SemaDeclCXX.cpp revision eef00293897a73cc47f4d42e2653ff47c59d6030
1//===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file implements semantic analysis for C++ declarations.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Sema/SemaInternal.h"
15#include "clang/Sema/CXXFieldCollector.h"
16#include "clang/Sema/Scope.h"
17#include "clang/Sema/Initialization.h"
18#include "clang/Sema/Lookup.h"
19#include "clang/Sema/ScopeInfo.h"
20#include "clang/AST/ASTConsumer.h"
21#include "clang/AST/ASTContext.h"
22#include "clang/AST/ASTMutationListener.h"
23#include "clang/AST/CharUnits.h"
24#include "clang/AST/CXXInheritance.h"
25#include "clang/AST/DeclVisitor.h"
26#include "clang/AST/EvaluatedExprVisitor.h"
27#include "clang/AST/ExprCXX.h"
28#include "clang/AST/RecordLayout.h"
29#include "clang/AST/RecursiveASTVisitor.h"
30#include "clang/AST/StmtVisitor.h"
31#include "clang/AST/TypeLoc.h"
32#include "clang/AST/TypeOrdering.h"
33#include "clang/Sema/DeclSpec.h"
34#include "clang/Sema/ParsedTemplate.h"
35#include "clang/Basic/PartialDiagnostic.h"
36#include "clang/Lex/Preprocessor.h"
37#include "llvm/ADT/SmallString.h"
38#include "llvm/ADT/STLExtras.h"
39#include <map>
40#include <set>
41
42using namespace clang;
43
44//===----------------------------------------------------------------------===//
45// CheckDefaultArgumentVisitor
46//===----------------------------------------------------------------------===//
47
48namespace {
49  /// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
50  /// the default argument of a parameter to determine whether it
51  /// contains any ill-formed subexpressions. For example, this will
52  /// diagnose the use of local variables or parameters within the
53  /// default argument expression.
54  class CheckDefaultArgumentVisitor
55    : public StmtVisitor<CheckDefaultArgumentVisitor, bool> {
56    Expr *DefaultArg;
57    Sema *S;
58
59  public:
60    CheckDefaultArgumentVisitor(Expr *defarg, Sema *s)
61      : DefaultArg(defarg), S(s) {}
62
63    bool VisitExpr(Expr *Node);
64    bool VisitDeclRefExpr(DeclRefExpr *DRE);
65    bool VisitCXXThisExpr(CXXThisExpr *ThisE);
66    bool VisitLambdaExpr(LambdaExpr *Lambda);
67  };
68
69  /// VisitExpr - Visit all of the children of this expression.
70  bool CheckDefaultArgumentVisitor::VisitExpr(Expr *Node) {
71    bool IsInvalid = false;
72    for (Stmt::child_range I = Node->children(); I; ++I)
73      IsInvalid |= Visit(*I);
74    return IsInvalid;
75  }
76
77  /// VisitDeclRefExpr - Visit a reference to a declaration, to
78  /// determine whether this declaration can be used in the default
79  /// argument expression.
80  bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(DeclRefExpr *DRE) {
81    NamedDecl *Decl = DRE->getDecl();
82    if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Decl)) {
83      // C++ [dcl.fct.default]p9
84      //   Default arguments are evaluated each time the function is
85      //   called. The order of evaluation of function arguments is
86      //   unspecified. Consequently, parameters of a function shall not
87      //   be used in default argument expressions, even if they are not
88      //   evaluated. Parameters of a function declared before a default
89      //   argument expression are in scope and can hide namespace and
90      //   class member names.
91      return S->Diag(DRE->getLocStart(),
92                     diag::err_param_default_argument_references_param)
93         << Param->getDeclName() << DefaultArg->getSourceRange();
94    } else if (VarDecl *VDecl = dyn_cast<VarDecl>(Decl)) {
95      // C++ [dcl.fct.default]p7
96      //   Local variables shall not be used in default argument
97      //   expressions.
98      if (VDecl->isLocalVarDecl())
99        return S->Diag(DRE->getLocStart(),
100                       diag::err_param_default_argument_references_local)
101          << VDecl->getDeclName() << DefaultArg->getSourceRange();
102    }
103
104    return false;
105  }
106
107  /// VisitCXXThisExpr - Visit a C++ "this" expression.
108  bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(CXXThisExpr *ThisE) {
109    // C++ [dcl.fct.default]p8:
110    //   The keyword this shall not be used in a default argument of a
111    //   member function.
112    return S->Diag(ThisE->getLocStart(),
113                   diag::err_param_default_argument_references_this)
114               << ThisE->getSourceRange();
115  }
116
117  bool CheckDefaultArgumentVisitor::VisitLambdaExpr(LambdaExpr *Lambda) {
118    // C++11 [expr.lambda.prim]p13:
119    //   A lambda-expression appearing in a default argument shall not
120    //   implicitly or explicitly capture any entity.
121    if (Lambda->capture_begin() == Lambda->capture_end())
122      return false;
123
124    return S->Diag(Lambda->getLocStart(),
125                   diag::err_lambda_capture_default_arg);
126  }
127}
128
129void Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc,
130                                                      CXXMethodDecl *Method) {
131  // If we have an MSAny spec already, don't bother.
132  if (!Method || ComputedEST == EST_MSAny)
133    return;
134
135  const FunctionProtoType *Proto
136    = Method->getType()->getAs<FunctionProtoType>();
137  Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
138  if (!Proto)
139    return;
140
141  ExceptionSpecificationType EST = Proto->getExceptionSpecType();
142
143  // If this function can throw any exceptions, make a note of that.
144  if (EST == EST_MSAny || EST == EST_None) {
145    ClearExceptions();
146    ComputedEST = EST;
147    return;
148  }
149
150  // FIXME: If the call to this decl is using any of its default arguments, we
151  // need to search them for potentially-throwing calls.
152
153  // If this function has a basic noexcept, it doesn't affect the outcome.
154  if (EST == EST_BasicNoexcept)
155    return;
156
157  // If we have a throw-all spec at this point, ignore the function.
158  if (ComputedEST == EST_None)
159    return;
160
161  // If we're still at noexcept(true) and there's a nothrow() callee,
162  // change to that specification.
163  if (EST == EST_DynamicNone) {
164    if (ComputedEST == EST_BasicNoexcept)
165      ComputedEST = EST_DynamicNone;
166    return;
167  }
168
169  // Check out noexcept specs.
170  if (EST == EST_ComputedNoexcept) {
171    FunctionProtoType::NoexceptResult NR =
172        Proto->getNoexceptSpec(Self->Context);
173    assert(NR != FunctionProtoType::NR_NoNoexcept &&
174           "Must have noexcept result for EST_ComputedNoexcept.");
175    assert(NR != FunctionProtoType::NR_Dependent &&
176           "Should not generate implicit declarations for dependent cases, "
177           "and don't know how to handle them anyway.");
178
179    // noexcept(false) -> no spec on the new function
180    if (NR == FunctionProtoType::NR_Throw) {
181      ClearExceptions();
182      ComputedEST = EST_None;
183    }
184    // noexcept(true) won't change anything either.
185    return;
186  }
187
188  assert(EST == EST_Dynamic && "EST case not considered earlier.");
189  assert(ComputedEST != EST_None &&
190         "Shouldn't collect exceptions when throw-all is guaranteed.");
191  ComputedEST = EST_Dynamic;
192  // Record the exceptions in this function's exception specification.
193  for (FunctionProtoType::exception_iterator E = Proto->exception_begin(),
194                                          EEnd = Proto->exception_end();
195       E != EEnd; ++E)
196    if (ExceptionsSeen.insert(Self->Context.getCanonicalType(*E)))
197      Exceptions.push_back(*E);
198}
199
200void Sema::ImplicitExceptionSpecification::CalledExpr(Expr *E) {
201  if (!E || ComputedEST == EST_MSAny)
202    return;
203
204  // FIXME:
205  //
206  // C++0x [except.spec]p14:
207  //   [An] implicit exception-specification specifies the type-id T if and
208  // only if T is allowed by the exception-specification of a function directly
209  // invoked by f's implicit definition; f shall allow all exceptions if any
210  // function it directly invokes allows all exceptions, and f shall allow no
211  // exceptions if every function it directly invokes allows no exceptions.
212  //
213  // Note in particular that if an implicit exception-specification is generated
214  // for a function containing a throw-expression, that specification can still
215  // be noexcept(true).
216  //
217  // Note also that 'directly invoked' is not defined in the standard, and there
218  // is no indication that we should only consider potentially-evaluated calls.
219  //
220  // Ultimately we should implement the intent of the standard: the exception
221  // specification should be the set of exceptions which can be thrown by the
222  // implicit definition. For now, we assume that any non-nothrow expression can
223  // throw any exception.
224
225  if (Self->canThrow(E))
226    ComputedEST = EST_None;
227}
228
229bool
230Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
231                              SourceLocation EqualLoc) {
232  if (RequireCompleteType(Param->getLocation(), Param->getType(),
233                          diag::err_typecheck_decl_incomplete_type)) {
234    Param->setInvalidDecl();
235    return true;
236  }
237
238  // C++ [dcl.fct.default]p5
239  //   A default argument expression is implicitly converted (clause
240  //   4) to the parameter type. The default argument expression has
241  //   the same semantic constraints as the initializer expression in
242  //   a declaration of a variable of the parameter type, using the
243  //   copy-initialization semantics (8.5).
244  InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
245                                                                    Param);
246  InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(),
247                                                           EqualLoc);
248  InitializationSequence InitSeq(*this, Entity, Kind, &Arg, 1);
249  ExprResult Result = InitSeq.Perform(*this, Entity, Kind,
250                                      MultiExprArg(*this, &Arg, 1));
251  if (Result.isInvalid())
252    return true;
253  Arg = Result.takeAs<Expr>();
254
255  CheckImplicitConversions(Arg, EqualLoc);
256  Arg = MaybeCreateExprWithCleanups(Arg);
257
258  // Okay: add the default argument to the parameter
259  Param->setDefaultArg(Arg);
260
261  // We have already instantiated this parameter; provide each of the
262  // instantiations with the uninstantiated default argument.
263  UnparsedDefaultArgInstantiationsMap::iterator InstPos
264    = UnparsedDefaultArgInstantiations.find(Param);
265  if (InstPos != UnparsedDefaultArgInstantiations.end()) {
266    for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
267      InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
268
269    // We're done tracking this parameter's instantiations.
270    UnparsedDefaultArgInstantiations.erase(InstPos);
271  }
272
273  return false;
274}
275
276/// ActOnParamDefaultArgument - Check whether the default argument
277/// provided for a function parameter is well-formed. If so, attach it
278/// to the parameter declaration.
279void
280Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc,
281                                Expr *DefaultArg) {
282  if (!param || !DefaultArg)
283    return;
284
285  ParmVarDecl *Param = cast<ParmVarDecl>(param);
286  UnparsedDefaultArgLocs.erase(Param);
287
288  // Default arguments are only permitted in C++
289  if (!getLangOpts().CPlusPlus) {
290    Diag(EqualLoc, diag::err_param_default_argument)
291      << DefaultArg->getSourceRange();
292    Param->setInvalidDecl();
293    return;
294  }
295
296  // Check for unexpanded parameter packs.
297  if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
298    Param->setInvalidDecl();
299    return;
300  }
301
302  // Check that the default argument is well-formed
303  CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg, this);
304  if (DefaultArgChecker.Visit(DefaultArg)) {
305    Param->setInvalidDecl();
306    return;
307  }
308
309  SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
310}
311
312/// ActOnParamUnparsedDefaultArgument - We've seen a default
313/// argument for a function parameter, but we can't parse it yet
314/// because we're inside a class definition. Note that this default
315/// argument will be parsed later.
316void Sema::ActOnParamUnparsedDefaultArgument(Decl *param,
317                                             SourceLocation EqualLoc,
318                                             SourceLocation ArgLoc) {
319  if (!param)
320    return;
321
322  ParmVarDecl *Param = cast<ParmVarDecl>(param);
323  if (Param)
324    Param->setUnparsedDefaultArg();
325
326  UnparsedDefaultArgLocs[Param] = ArgLoc;
327}
328
329/// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
330/// the default argument for the parameter param failed.
331void Sema::ActOnParamDefaultArgumentError(Decl *param) {
332  if (!param)
333    return;
334
335  ParmVarDecl *Param = cast<ParmVarDecl>(param);
336
337  Param->setInvalidDecl();
338
339  UnparsedDefaultArgLocs.erase(Param);
340}
341
342/// CheckExtraCXXDefaultArguments - Check for any extra default
343/// arguments in the declarator, which is not a function declaration
344/// or definition and therefore is not permitted to have default
345/// arguments. This routine should be invoked for every declarator
346/// that is not a function declaration or definition.
347void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
348  // C++ [dcl.fct.default]p3
349  //   A default argument expression shall be specified only in the
350  //   parameter-declaration-clause of a function declaration or in a
351  //   template-parameter (14.1). It shall not be specified for a
352  //   parameter pack. If it is specified in a
353  //   parameter-declaration-clause, it shall not occur within a
354  //   declarator or abstract-declarator of a parameter-declaration.
355  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
356    DeclaratorChunk &chunk = D.getTypeObject(i);
357    if (chunk.Kind == DeclaratorChunk::Function) {
358      for (unsigned argIdx = 0, e = chunk.Fun.NumArgs; argIdx != e; ++argIdx) {
359        ParmVarDecl *Param =
360          cast<ParmVarDecl>(chunk.Fun.ArgInfo[argIdx].Param);
361        if (Param->hasUnparsedDefaultArg()) {
362          CachedTokens *Toks = chunk.Fun.ArgInfo[argIdx].DefaultArgTokens;
363          Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
364            << SourceRange((*Toks)[1].getLocation(), Toks->back().getLocation());
365          delete Toks;
366          chunk.Fun.ArgInfo[argIdx].DefaultArgTokens = 0;
367        } else if (Param->getDefaultArg()) {
368          Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
369            << Param->getDefaultArg()->getSourceRange();
370          Param->setDefaultArg(0);
371        }
372      }
373    }
374  }
375}
376
377// MergeCXXFunctionDecl - Merge two declarations of the same C++
378// function, once we already know that they have the same
379// type. Subroutine of MergeFunctionDecl. Returns true if there was an
380// error, false otherwise.
381bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old,
382                                Scope *S) {
383  bool Invalid = false;
384
385  // C++ [dcl.fct.default]p4:
386  //   For non-template functions, default arguments can be added in
387  //   later declarations of a function in the same
388  //   scope. Declarations in different scopes have completely
389  //   distinct sets of default arguments. That is, declarations in
390  //   inner scopes do not acquire default arguments from
391  //   declarations in outer scopes, and vice versa. In a given
392  //   function declaration, all parameters subsequent to a
393  //   parameter with a default argument shall have default
394  //   arguments supplied in this or previous declarations. A
395  //   default argument shall not be redefined by a later
396  //   declaration (not even to the same value).
397  //
398  // C++ [dcl.fct.default]p6:
399  //   Except for member functions of class templates, the default arguments
400  //   in a member function definition that appears outside of the class
401  //   definition are added to the set of default arguments provided by the
402  //   member function declaration in the class definition.
403  for (unsigned p = 0, NumParams = Old->getNumParams(); p < NumParams; ++p) {
404    ParmVarDecl *OldParam = Old->getParamDecl(p);
405    ParmVarDecl *NewParam = New->getParamDecl(p);
406
407    bool OldParamHasDfl = OldParam->hasDefaultArg();
408    bool NewParamHasDfl = NewParam->hasDefaultArg();
409
410    NamedDecl *ND = Old;
411    if (S && !isDeclInScope(ND, New->getDeclContext(), S))
412      // Ignore default parameters of old decl if they are not in
413      // the same scope.
414      OldParamHasDfl = false;
415
416    if (OldParamHasDfl && NewParamHasDfl) {
417
418      unsigned DiagDefaultParamID =
419        diag::err_param_default_argument_redefinition;
420
421      // MSVC accepts that default parameters be redefined for member functions
422      // of template class. The new default parameter's value is ignored.
423      Invalid = true;
424      if (getLangOpts().MicrosoftExt) {
425        CXXMethodDecl* MD = dyn_cast<CXXMethodDecl>(New);
426        if (MD && MD->getParent()->getDescribedClassTemplate()) {
427          // Merge the old default argument into the new parameter.
428          NewParam->setHasInheritedDefaultArg();
429          if (OldParam->hasUninstantiatedDefaultArg())
430            NewParam->setUninstantiatedDefaultArg(
431                                      OldParam->getUninstantiatedDefaultArg());
432          else
433            NewParam->setDefaultArg(OldParam->getInit());
434          DiagDefaultParamID = diag::warn_param_default_argument_redefinition;
435          Invalid = false;
436        }
437      }
438
439      // FIXME: If we knew where the '=' was, we could easily provide a fix-it
440      // hint here. Alternatively, we could walk the type-source information
441      // for NewParam to find the last source location in the type... but it
442      // isn't worth the effort right now. This is the kind of test case that
443      // is hard to get right:
444      //   int f(int);
445      //   void g(int (*fp)(int) = f);
446      //   void g(int (*fp)(int) = &f);
447      Diag(NewParam->getLocation(), DiagDefaultParamID)
448        << NewParam->getDefaultArgRange();
449
450      // Look for the function declaration where the default argument was
451      // actually written, which may be a declaration prior to Old.
452      for (FunctionDecl *Older = Old->getPreviousDecl();
453           Older; Older = Older->getPreviousDecl()) {
454        if (!Older->getParamDecl(p)->hasDefaultArg())
455          break;
456
457        OldParam = Older->getParamDecl(p);
458      }
459
460      Diag(OldParam->getLocation(), diag::note_previous_definition)
461        << OldParam->getDefaultArgRange();
462    } else if (OldParamHasDfl) {
463      // Merge the old default argument into the new parameter.
464      // It's important to use getInit() here;  getDefaultArg()
465      // strips off any top-level ExprWithCleanups.
466      NewParam->setHasInheritedDefaultArg();
467      if (OldParam->hasUninstantiatedDefaultArg())
468        NewParam->setUninstantiatedDefaultArg(
469                                      OldParam->getUninstantiatedDefaultArg());
470      else
471        NewParam->setDefaultArg(OldParam->getInit());
472    } else if (NewParamHasDfl) {
473      if (New->getDescribedFunctionTemplate()) {
474        // Paragraph 4, quoted above, only applies to non-template functions.
475        Diag(NewParam->getLocation(),
476             diag::err_param_default_argument_template_redecl)
477          << NewParam->getDefaultArgRange();
478        Diag(Old->getLocation(), diag::note_template_prev_declaration)
479          << false;
480      } else if (New->getTemplateSpecializationKind()
481                   != TSK_ImplicitInstantiation &&
482                 New->getTemplateSpecializationKind() != TSK_Undeclared) {
483        // C++ [temp.expr.spec]p21:
484        //   Default function arguments shall not be specified in a declaration
485        //   or a definition for one of the following explicit specializations:
486        //     - the explicit specialization of a function template;
487        //     - the explicit specialization of a member function template;
488        //     - the explicit specialization of a member function of a class
489        //       template where the class template specialization to which the
490        //       member function specialization belongs is implicitly
491        //       instantiated.
492        Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
493          << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
494          << New->getDeclName()
495          << NewParam->getDefaultArgRange();
496      } else if (New->getDeclContext()->isDependentContext()) {
497        // C++ [dcl.fct.default]p6 (DR217):
498        //   Default arguments for a member function of a class template shall
499        //   be specified on the initial declaration of the member function
500        //   within the class template.
501        //
502        // Reading the tea leaves a bit in DR217 and its reference to DR205
503        // leads me to the conclusion that one cannot add default function
504        // arguments for an out-of-line definition of a member function of a
505        // dependent type.
506        int WhichKind = 2;
507        if (CXXRecordDecl *Record
508              = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
509          if (Record->getDescribedClassTemplate())
510            WhichKind = 0;
511          else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
512            WhichKind = 1;
513          else
514            WhichKind = 2;
515        }
516
517        Diag(NewParam->getLocation(),
518             diag::err_param_default_argument_member_template_redecl)
519          << WhichKind
520          << NewParam->getDefaultArgRange();
521      } else if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(New)) {
522        CXXSpecialMember NewSM = getSpecialMember(Ctor),
523                         OldSM = getSpecialMember(cast<CXXConstructorDecl>(Old));
524        if (NewSM != OldSM) {
525          Diag(NewParam->getLocation(),diag::warn_default_arg_makes_ctor_special)
526            << NewParam->getDefaultArgRange() << NewSM;
527          Diag(Old->getLocation(), diag::note_previous_declaration_special)
528            << OldSM;
529        }
530      }
531    }
532  }
533
534  // C++11 [dcl.constexpr]p1: If any declaration of a function or function
535  // template has a constexpr specifier then all its declarations shall
536  // contain the constexpr specifier.
537  if (New->isConstexpr() != Old->isConstexpr()) {
538    Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
539      << New << New->isConstexpr();
540    Diag(Old->getLocation(), diag::note_previous_declaration);
541    Invalid = true;
542  }
543
544  if (CheckEquivalentExceptionSpec(Old, New))
545    Invalid = true;
546
547  return Invalid;
548}
549
550/// \brief Merge the exception specifications of two variable declarations.
551///
552/// This is called when there's a redeclaration of a VarDecl. The function
553/// checks if the redeclaration might have an exception specification and
554/// validates compatibility and merges the specs if necessary.
555void Sema::MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old) {
556  // Shortcut if exceptions are disabled.
557  if (!getLangOpts().CXXExceptions)
558    return;
559
560  assert(Context.hasSameType(New->getType(), Old->getType()) &&
561         "Should only be called if types are otherwise the same.");
562
563  QualType NewType = New->getType();
564  QualType OldType = Old->getType();
565
566  // We're only interested in pointers and references to functions, as well
567  // as pointers to member functions.
568  if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
569    NewType = R->getPointeeType();
570    OldType = OldType->getAs<ReferenceType>()->getPointeeType();
571  } else if (const PointerType *P = NewType->getAs<PointerType>()) {
572    NewType = P->getPointeeType();
573    OldType = OldType->getAs<PointerType>()->getPointeeType();
574  } else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
575    NewType = M->getPointeeType();
576    OldType = OldType->getAs<MemberPointerType>()->getPointeeType();
577  }
578
579  if (!NewType->isFunctionProtoType())
580    return;
581
582  // There's lots of special cases for functions. For function pointers, system
583  // libraries are hopefully not as broken so that we don't need these
584  // workarounds.
585  if (CheckEquivalentExceptionSpec(
586        OldType->getAs<FunctionProtoType>(), Old->getLocation(),
587        NewType->getAs<FunctionProtoType>(), New->getLocation())) {
588    New->setInvalidDecl();
589  }
590}
591
592/// CheckCXXDefaultArguments - Verify that the default arguments for a
593/// function declaration are well-formed according to C++
594/// [dcl.fct.default].
595void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
596  unsigned NumParams = FD->getNumParams();
597  unsigned p;
598
599  bool IsLambda = FD->getOverloadedOperator() == OO_Call &&
600                  isa<CXXMethodDecl>(FD) &&
601                  cast<CXXMethodDecl>(FD)->getParent()->isLambda();
602
603  // Find first parameter with a default argument
604  for (p = 0; p < NumParams; ++p) {
605    ParmVarDecl *Param = FD->getParamDecl(p);
606    if (Param->hasDefaultArg()) {
607      // C++11 [expr.prim.lambda]p5:
608      //   [...] Default arguments (8.3.6) shall not be specified in the
609      //   parameter-declaration-clause of a lambda-declarator.
610      //
611      // FIXME: Core issue 974 strikes this sentence, we only provide an
612      // extension warning.
613      if (IsLambda)
614        Diag(Param->getLocation(), diag::ext_lambda_default_arguments)
615          << Param->getDefaultArgRange();
616      break;
617    }
618  }
619
620  // C++ [dcl.fct.default]p4:
621  //   In a given function declaration, all parameters
622  //   subsequent to a parameter with a default argument shall
623  //   have default arguments supplied in this or previous
624  //   declarations. A default argument shall not be redefined
625  //   by a later declaration (not even to the same value).
626  unsigned LastMissingDefaultArg = 0;
627  for (; p < NumParams; ++p) {
628    ParmVarDecl *Param = FD->getParamDecl(p);
629    if (!Param->hasDefaultArg()) {
630      if (Param->isInvalidDecl())
631        /* We already complained about this parameter. */;
632      else if (Param->getIdentifier())
633        Diag(Param->getLocation(),
634             diag::err_param_default_argument_missing_name)
635          << Param->getIdentifier();
636      else
637        Diag(Param->getLocation(),
638             diag::err_param_default_argument_missing);
639
640      LastMissingDefaultArg = p;
641    }
642  }
643
644  if (LastMissingDefaultArg > 0) {
645    // Some default arguments were missing. Clear out all of the
646    // default arguments up to (and including) the last missing
647    // default argument, so that we leave the function parameters
648    // in a semantically valid state.
649    for (p = 0; p <= LastMissingDefaultArg; ++p) {
650      ParmVarDecl *Param = FD->getParamDecl(p);
651      if (Param->hasDefaultArg()) {
652        Param->setDefaultArg(0);
653      }
654    }
655  }
656}
657
658// CheckConstexprParameterTypes - Check whether a function's parameter types
659// are all literal types. If so, return true. If not, produce a suitable
660// diagnostic and return false.
661static bool CheckConstexprParameterTypes(Sema &SemaRef,
662                                         const FunctionDecl *FD) {
663  unsigned ArgIndex = 0;
664  const FunctionProtoType *FT = FD->getType()->getAs<FunctionProtoType>();
665  for (FunctionProtoType::arg_type_iterator i = FT->arg_type_begin(),
666       e = FT->arg_type_end(); i != e; ++i, ++ArgIndex) {
667    const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
668    SourceLocation ParamLoc = PD->getLocation();
669    if (!(*i)->isDependentType() &&
670        SemaRef.RequireLiteralType(ParamLoc, *i,
671                                   diag::err_constexpr_non_literal_param,
672                                   ArgIndex+1, PD->getSourceRange(),
673                                   isa<CXXConstructorDecl>(FD)))
674      return false;
675  }
676  return true;
677}
678
679// CheckConstexprFunctionDecl - Check whether a function declaration satisfies
680// the requirements of a constexpr function definition or a constexpr
681// constructor definition. If so, return true. If not, produce appropriate
682// diagnostics and return false.
683//
684// This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
685bool Sema::CheckConstexprFunctionDecl(const FunctionDecl *NewFD) {
686  const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
687  if (MD && MD->isInstance()) {
688    // C++11 [dcl.constexpr]p4:
689    //  The definition of a constexpr constructor shall satisfy the following
690    //  constraints:
691    //  - the class shall not have any virtual base classes;
692    const CXXRecordDecl *RD = MD->getParent();
693    if (RD->getNumVBases()) {
694      Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
695        << isa<CXXConstructorDecl>(NewFD) << RD->isStruct()
696        << RD->getNumVBases();
697      for (CXXRecordDecl::base_class_const_iterator I = RD->vbases_begin(),
698             E = RD->vbases_end(); I != E; ++I)
699        Diag(I->getLocStart(),
700             diag::note_constexpr_virtual_base_here) << I->getSourceRange();
701      return false;
702    }
703  }
704
705  if (!isa<CXXConstructorDecl>(NewFD)) {
706    // C++11 [dcl.constexpr]p3:
707    //  The definition of a constexpr function shall satisfy the following
708    //  constraints:
709    // - it shall not be virtual;
710    const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
711    if (Method && Method->isVirtual()) {
712      Diag(NewFD->getLocation(), diag::err_constexpr_virtual);
713
714      // If it's not obvious why this function is virtual, find an overridden
715      // function which uses the 'virtual' keyword.
716      const CXXMethodDecl *WrittenVirtual = Method;
717      while (!WrittenVirtual->isVirtualAsWritten())
718        WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
719      if (WrittenVirtual != Method)
720        Diag(WrittenVirtual->getLocation(),
721             diag::note_overridden_virtual_function);
722      return false;
723    }
724
725    // - its return type shall be a literal type;
726    QualType RT = NewFD->getResultType();
727    if (!RT->isDependentType() &&
728        RequireLiteralType(NewFD->getLocation(), RT,
729                           diag::err_constexpr_non_literal_return))
730      return false;
731  }
732
733  // - each of its parameter types shall be a literal type;
734  if (!CheckConstexprParameterTypes(*this, NewFD))
735    return false;
736
737  return true;
738}
739
740/// Check the given declaration statement is legal within a constexpr function
741/// body. C++0x [dcl.constexpr]p3,p4.
742///
743/// \return true if the body is OK, false if we have diagnosed a problem.
744static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
745                                   DeclStmt *DS) {
746  // C++0x [dcl.constexpr]p3 and p4:
747  //  The definition of a constexpr function(p3) or constructor(p4) [...] shall
748  //  contain only
749  for (DeclStmt::decl_iterator DclIt = DS->decl_begin(),
750         DclEnd = DS->decl_end(); DclIt != DclEnd; ++DclIt) {
751    switch ((*DclIt)->getKind()) {
752    case Decl::StaticAssert:
753    case Decl::Using:
754    case Decl::UsingShadow:
755    case Decl::UsingDirective:
756    case Decl::UnresolvedUsingTypename:
757      //   - static_assert-declarations
758      //   - using-declarations,
759      //   - using-directives,
760      continue;
761
762    case Decl::Typedef:
763    case Decl::TypeAlias: {
764      //   - typedef declarations and alias-declarations that do not define
765      //     classes or enumerations,
766      TypedefNameDecl *TN = cast<TypedefNameDecl>(*DclIt);
767      if (TN->getUnderlyingType()->isVariablyModifiedType()) {
768        // Don't allow variably-modified types in constexpr functions.
769        TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
770        SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
771          << TL.getSourceRange() << TL.getType()
772          << isa<CXXConstructorDecl>(Dcl);
773        return false;
774      }
775      continue;
776    }
777
778    case Decl::Enum:
779    case Decl::CXXRecord:
780      // As an extension, we allow the declaration (but not the definition) of
781      // classes and enumerations in all declarations, not just in typedef and
782      // alias declarations.
783      if (cast<TagDecl>(*DclIt)->isThisDeclarationADefinition()) {
784        SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_type_definition)
785          << isa<CXXConstructorDecl>(Dcl);
786        return false;
787      }
788      continue;
789
790    case Decl::Var:
791      SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_var_declaration)
792        << isa<CXXConstructorDecl>(Dcl);
793      return false;
794
795    default:
796      SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_body_invalid_stmt)
797        << isa<CXXConstructorDecl>(Dcl);
798      return false;
799    }
800  }
801
802  return true;
803}
804
805/// Check that the given field is initialized within a constexpr constructor.
806///
807/// \param Dcl The constexpr constructor being checked.
808/// \param Field The field being checked. This may be a member of an anonymous
809///        struct or union nested within the class being checked.
810/// \param Inits All declarations, including anonymous struct/union members and
811///        indirect members, for which any initialization was provided.
812/// \param Diagnosed Set to true if an error is produced.
813static void CheckConstexprCtorInitializer(Sema &SemaRef,
814                                          const FunctionDecl *Dcl,
815                                          FieldDecl *Field,
816                                          llvm::SmallSet<Decl*, 16> &Inits,
817                                          bool &Diagnosed) {
818  if (Field->isUnnamedBitfield())
819    return;
820
821  if (Field->isAnonymousStructOrUnion() &&
822      Field->getType()->getAsCXXRecordDecl()->isEmpty())
823    return;
824
825  if (!Inits.count(Field)) {
826    if (!Diagnosed) {
827      SemaRef.Diag(Dcl->getLocation(), diag::err_constexpr_ctor_missing_init);
828      Diagnosed = true;
829    }
830    SemaRef.Diag(Field->getLocation(), diag::note_constexpr_ctor_missing_init);
831  } else if (Field->isAnonymousStructOrUnion()) {
832    const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
833    for (RecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end();
834         I != E; ++I)
835      // If an anonymous union contains an anonymous struct of which any member
836      // is initialized, all members must be initialized.
837      if (!RD->isUnion() || Inits.count(*I))
838        CheckConstexprCtorInitializer(SemaRef, Dcl, *I, Inits, Diagnosed);
839  }
840}
841
842/// Check the body for the given constexpr function declaration only contains
843/// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
844///
845/// \return true if the body is OK, false if we have diagnosed a problem.
846bool Sema::CheckConstexprFunctionBody(const FunctionDecl *Dcl, Stmt *Body) {
847  if (isa<CXXTryStmt>(Body)) {
848    // C++11 [dcl.constexpr]p3:
849    //  The definition of a constexpr function shall satisfy the following
850    //  constraints: [...]
851    // - its function-body shall be = delete, = default, or a
852    //   compound-statement
853    //
854    // C++11 [dcl.constexpr]p4:
855    //  In the definition of a constexpr constructor, [...]
856    // - its function-body shall not be a function-try-block;
857    Diag(Body->getLocStart(), diag::err_constexpr_function_try_block)
858      << isa<CXXConstructorDecl>(Dcl);
859    return false;
860  }
861
862  // - its function-body shall be [...] a compound-statement that contains only
863  CompoundStmt *CompBody = cast<CompoundStmt>(Body);
864
865  llvm::SmallVector<SourceLocation, 4> ReturnStmts;
866  for (CompoundStmt::body_iterator BodyIt = CompBody->body_begin(),
867         BodyEnd = CompBody->body_end(); BodyIt != BodyEnd; ++BodyIt) {
868    switch ((*BodyIt)->getStmtClass()) {
869    case Stmt::NullStmtClass:
870      //   - null statements,
871      continue;
872
873    case Stmt::DeclStmtClass:
874      //   - static_assert-declarations
875      //   - using-declarations,
876      //   - using-directives,
877      //   - typedef declarations and alias-declarations that do not define
878      //     classes or enumerations,
879      if (!CheckConstexprDeclStmt(*this, Dcl, cast<DeclStmt>(*BodyIt)))
880        return false;
881      continue;
882
883    case Stmt::ReturnStmtClass:
884      //   - and exactly one return statement;
885      if (isa<CXXConstructorDecl>(Dcl))
886        break;
887
888      ReturnStmts.push_back((*BodyIt)->getLocStart());
889      continue;
890
891    default:
892      break;
893    }
894
895    Diag((*BodyIt)->getLocStart(), diag::err_constexpr_body_invalid_stmt)
896      << isa<CXXConstructorDecl>(Dcl);
897    return false;
898  }
899
900  if (const CXXConstructorDecl *Constructor
901        = dyn_cast<CXXConstructorDecl>(Dcl)) {
902    const CXXRecordDecl *RD = Constructor->getParent();
903    // DR1359:
904    // - every non-variant non-static data member and base class sub-object
905    //   shall be initialized;
906    // - if the class is a non-empty union, or for each non-empty anonymous
907    //   union member of a non-union class, exactly one non-static data member
908    //   shall be initialized;
909    if (RD->isUnion()) {
910      if (Constructor->getNumCtorInitializers() == 0 && !RD->isEmpty()) {
911        Diag(Dcl->getLocation(), diag::err_constexpr_union_ctor_no_init);
912        return false;
913      }
914    } else if (!Constructor->isDependentContext() &&
915               !Constructor->isDelegatingConstructor()) {
916      assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases");
917
918      // Skip detailed checking if we have enough initializers, and we would
919      // allow at most one initializer per member.
920      bool AnyAnonStructUnionMembers = false;
921      unsigned Fields = 0;
922      for (CXXRecordDecl::field_iterator I = RD->field_begin(),
923           E = RD->field_end(); I != E; ++I, ++Fields) {
924        if (I->isAnonymousStructOrUnion()) {
925          AnyAnonStructUnionMembers = true;
926          break;
927        }
928      }
929      if (AnyAnonStructUnionMembers ||
930          Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
931        // Check initialization of non-static data members. Base classes are
932        // always initialized so do not need to be checked. Dependent bases
933        // might not have initializers in the member initializer list.
934        llvm::SmallSet<Decl*, 16> Inits;
935        for (CXXConstructorDecl::init_const_iterator
936               I = Constructor->init_begin(), E = Constructor->init_end();
937             I != E; ++I) {
938          if (FieldDecl *FD = (*I)->getMember())
939            Inits.insert(FD);
940          else if (IndirectFieldDecl *ID = (*I)->getIndirectMember())
941            Inits.insert(ID->chain_begin(), ID->chain_end());
942        }
943
944        bool Diagnosed = false;
945        for (CXXRecordDecl::field_iterator I = RD->field_begin(),
946             E = RD->field_end(); I != E; ++I)
947          CheckConstexprCtorInitializer(*this, Dcl, *I, Inits, Diagnosed);
948        if (Diagnosed)
949          return false;
950      }
951    }
952  } else {
953    if (ReturnStmts.empty()) {
954      Diag(Dcl->getLocation(), diag::err_constexpr_body_no_return);
955      return false;
956    }
957    if (ReturnStmts.size() > 1) {
958      Diag(ReturnStmts.back(), diag::err_constexpr_body_multiple_return);
959      for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
960        Diag(ReturnStmts[I], diag::note_constexpr_body_previous_return);
961      return false;
962    }
963  }
964
965  // C++11 [dcl.constexpr]p5:
966  //   if no function argument values exist such that the function invocation
967  //   substitution would produce a constant expression, the program is
968  //   ill-formed; no diagnostic required.
969  // C++11 [dcl.constexpr]p3:
970  //   - every constructor call and implicit conversion used in initializing the
971  //     return value shall be one of those allowed in a constant expression.
972  // C++11 [dcl.constexpr]p4:
973  //   - every constructor involved in initializing non-static data members and
974  //     base class sub-objects shall be a constexpr constructor.
975  llvm::SmallVector<PartialDiagnosticAt, 8> Diags;
976  if (!Expr::isPotentialConstantExpr(Dcl, Diags)) {
977    Diag(Dcl->getLocation(), diag::err_constexpr_function_never_constant_expr)
978      << isa<CXXConstructorDecl>(Dcl);
979    for (size_t I = 0, N = Diags.size(); I != N; ++I)
980      Diag(Diags[I].first, Diags[I].second);
981    return false;
982  }
983
984  return true;
985}
986
987/// isCurrentClassName - Determine whether the identifier II is the
988/// name of the class type currently being defined. In the case of
989/// nested classes, this will only return true if II is the name of
990/// the innermost class.
991bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *,
992                              const CXXScopeSpec *SS) {
993  assert(getLangOpts().CPlusPlus && "No class names in C!");
994
995  CXXRecordDecl *CurDecl;
996  if (SS && SS->isSet() && !SS->isInvalid()) {
997    DeclContext *DC = computeDeclContext(*SS, true);
998    CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
999  } else
1000    CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
1001
1002  if (CurDecl && CurDecl->getIdentifier())
1003    return &II == CurDecl->getIdentifier();
1004  else
1005    return false;
1006}
1007
1008/// \brief Check the validity of a C++ base class specifier.
1009///
1010/// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
1011/// and returns NULL otherwise.
1012CXXBaseSpecifier *
1013Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
1014                         SourceRange SpecifierRange,
1015                         bool Virtual, AccessSpecifier Access,
1016                         TypeSourceInfo *TInfo,
1017                         SourceLocation EllipsisLoc) {
1018  QualType BaseType = TInfo->getType();
1019
1020  // C++ [class.union]p1:
1021  //   A union shall not have base classes.
1022  if (Class->isUnion()) {
1023    Diag(Class->getLocation(), diag::err_base_clause_on_union)
1024      << SpecifierRange;
1025    return 0;
1026  }
1027
1028  if (EllipsisLoc.isValid() &&
1029      !TInfo->getType()->containsUnexpandedParameterPack()) {
1030    Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
1031      << TInfo->getTypeLoc().getSourceRange();
1032    EllipsisLoc = SourceLocation();
1033  }
1034
1035  if (BaseType->isDependentType())
1036    return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
1037                                          Class->getTagKind() == TTK_Class,
1038                                          Access, TInfo, EllipsisLoc);
1039
1040  SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
1041
1042  // Base specifiers must be record types.
1043  if (!BaseType->isRecordType()) {
1044    Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
1045    return 0;
1046  }
1047
1048  // C++ [class.union]p1:
1049  //   A union shall not be used as a base class.
1050  if (BaseType->isUnionType()) {
1051    Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
1052    return 0;
1053  }
1054
1055  // C++ [class.derived]p2:
1056  //   The class-name in a base-specifier shall not be an incompletely
1057  //   defined class.
1058  if (RequireCompleteType(BaseLoc, BaseType,
1059                          diag::err_incomplete_base_class, SpecifierRange)) {
1060    Class->setInvalidDecl();
1061    return 0;
1062  }
1063
1064  // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
1065  RecordDecl *BaseDecl = BaseType->getAs<RecordType>()->getDecl();
1066  assert(BaseDecl && "Record type has no declaration");
1067  BaseDecl = BaseDecl->getDefinition();
1068  assert(BaseDecl && "Base type is not incomplete, but has no definition");
1069  CXXRecordDecl * CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
1070  assert(CXXBaseDecl && "Base type is not a C++ type");
1071
1072  // C++ [class]p3:
1073  //   If a class is marked final and it appears as a base-type-specifier in
1074  //   base-clause, the program is ill-formed.
1075  if (CXXBaseDecl->hasAttr<FinalAttr>()) {
1076    Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
1077      << CXXBaseDecl->getDeclName();
1078    Diag(CXXBaseDecl->getLocation(), diag::note_previous_decl)
1079      << CXXBaseDecl->getDeclName();
1080    return 0;
1081  }
1082
1083  if (BaseDecl->isInvalidDecl())
1084    Class->setInvalidDecl();
1085
1086  // Create the base specifier.
1087  return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
1088                                        Class->getTagKind() == TTK_Class,
1089                                        Access, TInfo, EllipsisLoc);
1090}
1091
1092/// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
1093/// one entry in the base class list of a class specifier, for
1094/// example:
1095///    class foo : public bar, virtual private baz {
1096/// 'public bar' and 'virtual private baz' are each base-specifiers.
1097BaseResult
1098Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
1099                         bool Virtual, AccessSpecifier Access,
1100                         ParsedType basetype, SourceLocation BaseLoc,
1101                         SourceLocation EllipsisLoc) {
1102  if (!classdecl)
1103    return true;
1104
1105  AdjustDeclIfTemplate(classdecl);
1106  CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
1107  if (!Class)
1108    return true;
1109
1110  TypeSourceInfo *TInfo = 0;
1111  GetTypeFromParser(basetype, &TInfo);
1112
1113  if (EllipsisLoc.isInvalid() &&
1114      DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
1115                                      UPPC_BaseType))
1116    return true;
1117
1118  if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
1119                                                      Virtual, Access, TInfo,
1120                                                      EllipsisLoc))
1121    return BaseSpec;
1122  else
1123    Class->setInvalidDecl();
1124
1125  return true;
1126}
1127
1128/// \brief Performs the actual work of attaching the given base class
1129/// specifiers to a C++ class.
1130bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class, CXXBaseSpecifier **Bases,
1131                                unsigned NumBases) {
1132 if (NumBases == 0)
1133    return false;
1134
1135  // Used to keep track of which base types we have already seen, so
1136  // that we can properly diagnose redundant direct base types. Note
1137  // that the key is always the unqualified canonical type of the base
1138  // class.
1139  std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
1140
1141  // Copy non-redundant base specifiers into permanent storage.
1142  unsigned NumGoodBases = 0;
1143  bool Invalid = false;
1144  for (unsigned idx = 0; idx < NumBases; ++idx) {
1145    QualType NewBaseType
1146      = Context.getCanonicalType(Bases[idx]->getType());
1147    NewBaseType = NewBaseType.getLocalUnqualifiedType();
1148
1149    CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
1150    if (KnownBase) {
1151      // C++ [class.mi]p3:
1152      //   A class shall not be specified as a direct base class of a
1153      //   derived class more than once.
1154      Diag(Bases[idx]->getLocStart(),
1155           diag::err_duplicate_base_class)
1156        << KnownBase->getType()
1157        << Bases[idx]->getSourceRange();
1158
1159      // Delete the duplicate base class specifier; we're going to
1160      // overwrite its pointer later.
1161      Context.Deallocate(Bases[idx]);
1162
1163      Invalid = true;
1164    } else {
1165      // Okay, add this new base class.
1166      KnownBase = Bases[idx];
1167      Bases[NumGoodBases++] = Bases[idx];
1168      if (const RecordType *Record = NewBaseType->getAs<RecordType>())
1169        if (const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl()))
1170          if (RD->hasAttr<WeakAttr>())
1171            Class->addAttr(::new (Context) WeakAttr(SourceRange(), Context));
1172    }
1173  }
1174
1175  // Attach the remaining base class specifiers to the derived class.
1176  Class->setBases(Bases, NumGoodBases);
1177
1178  // Delete the remaining (good) base class specifiers, since their
1179  // data has been copied into the CXXRecordDecl.
1180  for (unsigned idx = 0; idx < NumGoodBases; ++idx)
1181    Context.Deallocate(Bases[idx]);
1182
1183  return Invalid;
1184}
1185
1186/// ActOnBaseSpecifiers - Attach the given base specifiers to the
1187/// class, after checking whether there are any duplicate base
1188/// classes.
1189void Sema::ActOnBaseSpecifiers(Decl *ClassDecl, CXXBaseSpecifier **Bases,
1190                               unsigned NumBases) {
1191  if (!ClassDecl || !Bases || !NumBases)
1192    return;
1193
1194  AdjustDeclIfTemplate(ClassDecl);
1195  AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl),
1196                       (CXXBaseSpecifier**)(Bases), NumBases);
1197}
1198
1199static CXXRecordDecl *GetClassForType(QualType T) {
1200  if (const RecordType *RT = T->getAs<RecordType>())
1201    return cast<CXXRecordDecl>(RT->getDecl());
1202  else if (const InjectedClassNameType *ICT = T->getAs<InjectedClassNameType>())
1203    return ICT->getDecl();
1204  else
1205    return 0;
1206}
1207
1208/// \brief Determine whether the type \p Derived is a C++ class that is
1209/// derived from the type \p Base.
1210bool Sema::IsDerivedFrom(QualType Derived, QualType Base) {
1211  if (!getLangOpts().CPlusPlus)
1212    return false;
1213
1214  CXXRecordDecl *DerivedRD = GetClassForType(Derived);
1215  if (!DerivedRD)
1216    return false;
1217
1218  CXXRecordDecl *BaseRD = GetClassForType(Base);
1219  if (!BaseRD)
1220    return false;
1221
1222  // FIXME: instantiate DerivedRD if necessary.  We need a PoI for this.
1223  return DerivedRD->hasDefinition() && DerivedRD->isDerivedFrom(BaseRD);
1224}
1225
1226/// \brief Determine whether the type \p Derived is a C++ class that is
1227/// derived from the type \p Base.
1228bool Sema::IsDerivedFrom(QualType Derived, QualType Base, CXXBasePaths &Paths) {
1229  if (!getLangOpts().CPlusPlus)
1230    return false;
1231
1232  CXXRecordDecl *DerivedRD = GetClassForType(Derived);
1233  if (!DerivedRD)
1234    return false;
1235
1236  CXXRecordDecl *BaseRD = GetClassForType(Base);
1237  if (!BaseRD)
1238    return false;
1239
1240  return DerivedRD->isDerivedFrom(BaseRD, Paths);
1241}
1242
1243void Sema::BuildBasePathArray(const CXXBasePaths &Paths,
1244                              CXXCastPath &BasePathArray) {
1245  assert(BasePathArray.empty() && "Base path array must be empty!");
1246  assert(Paths.isRecordingPaths() && "Must record paths!");
1247
1248  const CXXBasePath &Path = Paths.front();
1249
1250  // We first go backward and check if we have a virtual base.
1251  // FIXME: It would be better if CXXBasePath had the base specifier for
1252  // the nearest virtual base.
1253  unsigned Start = 0;
1254  for (unsigned I = Path.size(); I != 0; --I) {
1255    if (Path[I - 1].Base->isVirtual()) {
1256      Start = I - 1;
1257      break;
1258    }
1259  }
1260
1261  // Now add all bases.
1262  for (unsigned I = Start, E = Path.size(); I != E; ++I)
1263    BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
1264}
1265
1266/// \brief Determine whether the given base path includes a virtual
1267/// base class.
1268bool Sema::BasePathInvolvesVirtualBase(const CXXCastPath &BasePath) {
1269  for (CXXCastPath::const_iterator B = BasePath.begin(),
1270                                BEnd = BasePath.end();
1271       B != BEnd; ++B)
1272    if ((*B)->isVirtual())
1273      return true;
1274
1275  return false;
1276}
1277
1278/// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
1279/// conversion (where Derived and Base are class types) is
1280/// well-formed, meaning that the conversion is unambiguous (and
1281/// that all of the base classes are accessible). Returns true
1282/// and emits a diagnostic if the code is ill-formed, returns false
1283/// otherwise. Loc is the location where this routine should point to
1284/// if there is an error, and Range is the source range to highlight
1285/// if there is an error.
1286bool
1287Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
1288                                   unsigned InaccessibleBaseID,
1289                                   unsigned AmbigiousBaseConvID,
1290                                   SourceLocation Loc, SourceRange Range,
1291                                   DeclarationName Name,
1292                                   CXXCastPath *BasePath) {
1293  // First, determine whether the path from Derived to Base is
1294  // ambiguous. This is slightly more expensive than checking whether
1295  // the Derived to Base conversion exists, because here we need to
1296  // explore multiple paths to determine if there is an ambiguity.
1297  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1298                     /*DetectVirtual=*/false);
1299  bool DerivationOkay = IsDerivedFrom(Derived, Base, Paths);
1300  assert(DerivationOkay &&
1301         "Can only be used with a derived-to-base conversion");
1302  (void)DerivationOkay;
1303
1304  if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType())) {
1305    if (InaccessibleBaseID) {
1306      // Check that the base class can be accessed.
1307      switch (CheckBaseClassAccess(Loc, Base, Derived, Paths.front(),
1308                                   InaccessibleBaseID)) {
1309        case AR_inaccessible:
1310          return true;
1311        case AR_accessible:
1312        case AR_dependent:
1313        case AR_delayed:
1314          break;
1315      }
1316    }
1317
1318    // Build a base path if necessary.
1319    if (BasePath)
1320      BuildBasePathArray(Paths, *BasePath);
1321    return false;
1322  }
1323
1324  // We know that the derived-to-base conversion is ambiguous, and
1325  // we're going to produce a diagnostic. Perform the derived-to-base
1326  // search just one more time to compute all of the possible paths so
1327  // that we can print them out. This is more expensive than any of
1328  // the previous derived-to-base checks we've done, but at this point
1329  // performance isn't as much of an issue.
1330  Paths.clear();
1331  Paths.setRecordingPaths(true);
1332  bool StillOkay = IsDerivedFrom(Derived, Base, Paths);
1333  assert(StillOkay && "Can only be used with a derived-to-base conversion");
1334  (void)StillOkay;
1335
1336  // Build up a textual representation of the ambiguous paths, e.g.,
1337  // D -> B -> A, that will be used to illustrate the ambiguous
1338  // conversions in the diagnostic. We only print one of the paths
1339  // to each base class subobject.
1340  std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
1341
1342  Diag(Loc, AmbigiousBaseConvID)
1343  << Derived << Base << PathDisplayStr << Range << Name;
1344  return true;
1345}
1346
1347bool
1348Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
1349                                   SourceLocation Loc, SourceRange Range,
1350                                   CXXCastPath *BasePath,
1351                                   bool IgnoreAccess) {
1352  return CheckDerivedToBaseConversion(Derived, Base,
1353                                      IgnoreAccess ? 0
1354                                       : diag::err_upcast_to_inaccessible_base,
1355                                      diag::err_ambiguous_derived_to_base_conv,
1356                                      Loc, Range, DeclarationName(),
1357                                      BasePath);
1358}
1359
1360
1361/// @brief Builds a string representing ambiguous paths from a
1362/// specific derived class to different subobjects of the same base
1363/// class.
1364///
1365/// This function builds a string that can be used in error messages
1366/// to show the different paths that one can take through the
1367/// inheritance hierarchy to go from the derived class to different
1368/// subobjects of a base class. The result looks something like this:
1369/// @code
1370/// struct D -> struct B -> struct A
1371/// struct D -> struct C -> struct A
1372/// @endcode
1373std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
1374  std::string PathDisplayStr;
1375  std::set<unsigned> DisplayedPaths;
1376  for (CXXBasePaths::paths_iterator Path = Paths.begin();
1377       Path != Paths.end(); ++Path) {
1378    if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
1379      // We haven't displayed a path to this particular base
1380      // class subobject yet.
1381      PathDisplayStr += "\n    ";
1382      PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
1383      for (CXXBasePath::const_iterator Element = Path->begin();
1384           Element != Path->end(); ++Element)
1385        PathDisplayStr += " -> " + Element->Base->getType().getAsString();
1386    }
1387  }
1388
1389  return PathDisplayStr;
1390}
1391
1392//===----------------------------------------------------------------------===//
1393// C++ class member Handling
1394//===----------------------------------------------------------------------===//
1395
1396/// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
1397bool Sema::ActOnAccessSpecifier(AccessSpecifier Access,
1398                                SourceLocation ASLoc,
1399                                SourceLocation ColonLoc,
1400                                AttributeList *Attrs) {
1401  assert(Access != AS_none && "Invalid kind for syntactic access specifier!");
1402  AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
1403                                                  ASLoc, ColonLoc);
1404  CurContext->addHiddenDecl(ASDecl);
1405  return ProcessAccessDeclAttributeList(ASDecl, Attrs);
1406}
1407
1408/// CheckOverrideControl - Check C++0x override control semantics.
1409void Sema::CheckOverrideControl(const Decl *D) {
1410  const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
1411  if (!MD || !MD->isVirtual())
1412    return;
1413
1414  if (MD->isDependentContext())
1415    return;
1416
1417  // C++0x [class.virtual]p3:
1418  //   If a virtual function is marked with the virt-specifier override and does
1419  //   not override a member function of a base class,
1420  //   the program is ill-formed.
1421  bool HasOverriddenMethods =
1422    MD->begin_overridden_methods() != MD->end_overridden_methods();
1423  if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods) {
1424    Diag(MD->getLocation(),
1425                 diag::err_function_marked_override_not_overriding)
1426      << MD->getDeclName();
1427    return;
1428  }
1429}
1430
1431/// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
1432/// function overrides a virtual member function marked 'final', according to
1433/// C++0x [class.virtual]p3.
1434bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
1435                                                  const CXXMethodDecl *Old) {
1436  if (!Old->hasAttr<FinalAttr>())
1437    return false;
1438
1439  Diag(New->getLocation(), diag::err_final_function_overridden)
1440    << New->getDeclName();
1441  Diag(Old->getLocation(), diag::note_overridden_virtual_function);
1442  return true;
1443}
1444
1445static bool InitializationHasSideEffects(const FieldDecl &FD) {
1446  if (!FD.getType().isNull()) {
1447    if (const CXXRecordDecl *RD = FD.getType()->getAsCXXRecordDecl()) {
1448      return !RD->isCompleteDefinition() ||
1449             !RD->hasTrivialDefaultConstructor() ||
1450             !RD->hasTrivialDestructor();
1451    }
1452  }
1453  return false;
1454}
1455
1456/// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
1457/// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
1458/// bitfield width if there is one, 'InitExpr' specifies the initializer if
1459/// one has been parsed, and 'InitStyle' is set if an in-class initializer is
1460/// present (but parsing it has been deferred).
1461Decl *
1462Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
1463                               MultiTemplateParamsArg TemplateParameterLists,
1464                               Expr *BW, const VirtSpecifiers &VS,
1465                               InClassInitStyle InitStyle) {
1466  const DeclSpec &DS = D.getDeclSpec();
1467  DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
1468  DeclarationName Name = NameInfo.getName();
1469  SourceLocation Loc = NameInfo.getLoc();
1470
1471  // For anonymous bitfields, the location should point to the type.
1472  if (Loc.isInvalid())
1473    Loc = D.getLocStart();
1474
1475  Expr *BitWidth = static_cast<Expr*>(BW);
1476
1477  assert(isa<CXXRecordDecl>(CurContext));
1478  assert(!DS.isFriendSpecified());
1479
1480  bool isFunc = D.isDeclarationOfFunction();
1481
1482  // C++ 9.2p6: A member shall not be declared to have automatic storage
1483  // duration (auto, register) or with the extern storage-class-specifier.
1484  // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
1485  // data members and cannot be applied to names declared const or static,
1486  // and cannot be applied to reference members.
1487  switch (DS.getStorageClassSpec()) {
1488    case DeclSpec::SCS_unspecified:
1489    case DeclSpec::SCS_typedef:
1490    case DeclSpec::SCS_static:
1491      // FALL THROUGH.
1492      break;
1493    case DeclSpec::SCS_mutable:
1494      if (isFunc) {
1495        if (DS.getStorageClassSpecLoc().isValid())
1496          Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
1497        else
1498          Diag(DS.getThreadSpecLoc(), diag::err_mutable_function);
1499
1500        // FIXME: It would be nicer if the keyword was ignored only for this
1501        // declarator. Otherwise we could get follow-up errors.
1502        D.getMutableDeclSpec().ClearStorageClassSpecs();
1503      }
1504      break;
1505    default:
1506      if (DS.getStorageClassSpecLoc().isValid())
1507        Diag(DS.getStorageClassSpecLoc(),
1508             diag::err_storageclass_invalid_for_member);
1509      else
1510        Diag(DS.getThreadSpecLoc(), diag::err_storageclass_invalid_for_member);
1511      D.getMutableDeclSpec().ClearStorageClassSpecs();
1512  }
1513
1514  bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
1515                       DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
1516                      !isFunc);
1517
1518  Decl *Member;
1519  if (isInstField) {
1520    CXXScopeSpec &SS = D.getCXXScopeSpec();
1521
1522    // Data members must have identifiers for names.
1523    if (!Name.isIdentifier()) {
1524      Diag(Loc, diag::err_bad_variable_name)
1525        << Name;
1526      return 0;
1527    }
1528
1529    IdentifierInfo *II = Name.getAsIdentifierInfo();
1530
1531    // Member field could not be with "template" keyword.
1532    // So TemplateParameterLists should be empty in this case.
1533    if (TemplateParameterLists.size()) {
1534      TemplateParameterList* TemplateParams = TemplateParameterLists.get()[0];
1535      if (TemplateParams->size()) {
1536        // There is no such thing as a member field template.
1537        Diag(D.getIdentifierLoc(), diag::err_template_member)
1538            << II
1539            << SourceRange(TemplateParams->getTemplateLoc(),
1540                TemplateParams->getRAngleLoc());
1541      } else {
1542        // There is an extraneous 'template<>' for this member.
1543        Diag(TemplateParams->getTemplateLoc(),
1544            diag::err_template_member_noparams)
1545            << II
1546            << SourceRange(TemplateParams->getTemplateLoc(),
1547                TemplateParams->getRAngleLoc());
1548      }
1549      return 0;
1550    }
1551
1552    if (SS.isSet() && !SS.isInvalid()) {
1553      // The user provided a superfluous scope specifier inside a class
1554      // definition:
1555      //
1556      // class X {
1557      //   int X::member;
1558      // };
1559      if (DeclContext *DC = computeDeclContext(SS, false))
1560        diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc());
1561      else
1562        Diag(D.getIdentifierLoc(), diag::err_member_qualification)
1563          << Name << SS.getRange();
1564
1565      SS.clear();
1566    }
1567
1568    Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D, BitWidth,
1569                         InitStyle, AS);
1570    assert(Member && "HandleField never returns null");
1571  } else {
1572    assert(InitStyle == ICIS_NoInit);
1573
1574    Member = HandleDeclarator(S, D, move(TemplateParameterLists));
1575    if (!Member) {
1576      return 0;
1577    }
1578
1579    // Non-instance-fields can't have a bitfield.
1580    if (BitWidth) {
1581      if (Member->isInvalidDecl()) {
1582        // don't emit another diagnostic.
1583      } else if (isa<VarDecl>(Member)) {
1584        // C++ 9.6p3: A bit-field shall not be a static member.
1585        // "static member 'A' cannot be a bit-field"
1586        Diag(Loc, diag::err_static_not_bitfield)
1587          << Name << BitWidth->getSourceRange();
1588      } else if (isa<TypedefDecl>(Member)) {
1589        // "typedef member 'x' cannot be a bit-field"
1590        Diag(Loc, diag::err_typedef_not_bitfield)
1591          << Name << BitWidth->getSourceRange();
1592      } else {
1593        // A function typedef ("typedef int f(); f a;").
1594        // C++ 9.6p3: A bit-field shall have integral or enumeration type.
1595        Diag(Loc, diag::err_not_integral_type_bitfield)
1596          << Name << cast<ValueDecl>(Member)->getType()
1597          << BitWidth->getSourceRange();
1598      }
1599
1600      BitWidth = 0;
1601      Member->setInvalidDecl();
1602    }
1603
1604    Member->setAccess(AS);
1605
1606    // If we have declared a member function template, set the access of the
1607    // templated declaration as well.
1608    if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
1609      FunTmpl->getTemplatedDecl()->setAccess(AS);
1610  }
1611
1612  if (VS.isOverrideSpecified()) {
1613    CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
1614    if (!MD || !MD->isVirtual()) {
1615      Diag(Member->getLocStart(),
1616           diag::override_keyword_only_allowed_on_virtual_member_functions)
1617        << "override" << FixItHint::CreateRemoval(VS.getOverrideLoc());
1618    } else
1619      MD->addAttr(new (Context) OverrideAttr(VS.getOverrideLoc(), Context));
1620  }
1621  if (VS.isFinalSpecified()) {
1622    CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
1623    if (!MD || !MD->isVirtual()) {
1624      Diag(Member->getLocStart(),
1625           diag::override_keyword_only_allowed_on_virtual_member_functions)
1626      << "final" << FixItHint::CreateRemoval(VS.getFinalLoc());
1627    } else
1628      MD->addAttr(new (Context) FinalAttr(VS.getFinalLoc(), Context));
1629  }
1630
1631  if (VS.getLastLocation().isValid()) {
1632    // Update the end location of a method that has a virt-specifiers.
1633    if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
1634      MD->setRangeEnd(VS.getLastLocation());
1635  }
1636
1637  CheckOverrideControl(Member);
1638
1639  assert((Name || isInstField) && "No identifier for non-field ?");
1640
1641  if (isInstField) {
1642    FieldDecl *FD = cast<FieldDecl>(Member);
1643    FieldCollector->Add(FD);
1644
1645    if (Diags.getDiagnosticLevel(diag::warn_unused_private_field,
1646                                 FD->getLocation())
1647          != DiagnosticsEngine::Ignored) {
1648      // Remember all explicit private FieldDecls that have a name, no side
1649      // effects and are not part of a dependent type declaration.
1650      if (!FD->isImplicit() && FD->getDeclName() &&
1651          FD->getAccess() == AS_private &&
1652          !FD->hasAttr<UnusedAttr>() &&
1653          !FD->getParent()->getTypeForDecl()->isDependentType() &&
1654          !InitializationHasSideEffects(*FD))
1655        UnusedPrivateFields.insert(FD);
1656    }
1657  }
1658
1659  return Member;
1660}
1661
1662/// ActOnCXXInClassMemberInitializer - This is invoked after parsing an
1663/// in-class initializer for a non-static C++ class member, and after
1664/// instantiating an in-class initializer in a class template. Such actions
1665/// are deferred until the class is complete.
1666void
1667Sema::ActOnCXXInClassMemberInitializer(Decl *D, SourceLocation InitLoc,
1668                                       Expr *InitExpr) {
1669  FieldDecl *FD = cast<FieldDecl>(D);
1670  assert(FD->getInClassInitStyle() != ICIS_NoInit &&
1671         "must set init style when field is created");
1672
1673  if (!InitExpr) {
1674    FD->setInvalidDecl();
1675    FD->removeInClassInitializer();
1676    return;
1677  }
1678
1679  if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
1680    FD->setInvalidDecl();
1681    FD->removeInClassInitializer();
1682    return;
1683  }
1684
1685  ExprResult Init = InitExpr;
1686  if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
1687    if (isa<InitListExpr>(InitExpr) && isStdInitializerList(FD->getType(), 0)) {
1688      Diag(FD->getLocation(), diag::warn_dangling_std_initializer_list)
1689        << /*at end of ctor*/1 << InitExpr->getSourceRange();
1690    }
1691    Expr **Inits = &InitExpr;
1692    unsigned NumInits = 1;
1693    InitializedEntity Entity = InitializedEntity::InitializeMember(FD);
1694    InitializationKind Kind = FD->getInClassInitStyle() == ICIS_ListInit
1695        ? InitializationKind::CreateDirectList(InitExpr->getLocStart())
1696        : InitializationKind::CreateCopy(InitExpr->getLocStart(), InitLoc);
1697    InitializationSequence Seq(*this, Entity, Kind, Inits, NumInits);
1698    Init = Seq.Perform(*this, Entity, Kind, MultiExprArg(Inits, NumInits));
1699    if (Init.isInvalid()) {
1700      FD->setInvalidDecl();
1701      return;
1702    }
1703
1704    CheckImplicitConversions(Init.get(), InitLoc);
1705  }
1706
1707  // C++0x [class.base.init]p7:
1708  //   The initialization of each base and member constitutes a
1709  //   full-expression.
1710  Init = MaybeCreateExprWithCleanups(Init);
1711  if (Init.isInvalid()) {
1712    FD->setInvalidDecl();
1713    return;
1714  }
1715
1716  InitExpr = Init.release();
1717
1718  FD->setInClassInitializer(InitExpr);
1719}
1720
1721/// \brief Find the direct and/or virtual base specifiers that
1722/// correspond to the given base type, for use in base initialization
1723/// within a constructor.
1724static bool FindBaseInitializer(Sema &SemaRef,
1725                                CXXRecordDecl *ClassDecl,
1726                                QualType BaseType,
1727                                const CXXBaseSpecifier *&DirectBaseSpec,
1728                                const CXXBaseSpecifier *&VirtualBaseSpec) {
1729  // First, check for a direct base class.
1730  DirectBaseSpec = 0;
1731  for (CXXRecordDecl::base_class_const_iterator Base
1732         = ClassDecl->bases_begin();
1733       Base != ClassDecl->bases_end(); ++Base) {
1734    if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base->getType())) {
1735      // We found a direct base of this type. That's what we're
1736      // initializing.
1737      DirectBaseSpec = &*Base;
1738      break;
1739    }
1740  }
1741
1742  // Check for a virtual base class.
1743  // FIXME: We might be able to short-circuit this if we know in advance that
1744  // there are no virtual bases.
1745  VirtualBaseSpec = 0;
1746  if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
1747    // We haven't found a base yet; search the class hierarchy for a
1748    // virtual base class.
1749    CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1750                       /*DetectVirtual=*/false);
1751    if (SemaRef.IsDerivedFrom(SemaRef.Context.getTypeDeclType(ClassDecl),
1752                              BaseType, Paths)) {
1753      for (CXXBasePaths::paths_iterator Path = Paths.begin();
1754           Path != Paths.end(); ++Path) {
1755        if (Path->back().Base->isVirtual()) {
1756          VirtualBaseSpec = Path->back().Base;
1757          break;
1758        }
1759      }
1760    }
1761  }
1762
1763  return DirectBaseSpec || VirtualBaseSpec;
1764}
1765
1766/// \brief Handle a C++ member initializer using braced-init-list syntax.
1767MemInitResult
1768Sema::ActOnMemInitializer(Decl *ConstructorD,
1769                          Scope *S,
1770                          CXXScopeSpec &SS,
1771                          IdentifierInfo *MemberOrBase,
1772                          ParsedType TemplateTypeTy,
1773                          const DeclSpec &DS,
1774                          SourceLocation IdLoc,
1775                          Expr *InitList,
1776                          SourceLocation EllipsisLoc) {
1777  return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
1778                             DS, IdLoc, InitList,
1779                             EllipsisLoc);
1780}
1781
1782/// \brief Handle a C++ member initializer using parentheses syntax.
1783MemInitResult
1784Sema::ActOnMemInitializer(Decl *ConstructorD,
1785                          Scope *S,
1786                          CXXScopeSpec &SS,
1787                          IdentifierInfo *MemberOrBase,
1788                          ParsedType TemplateTypeTy,
1789                          const DeclSpec &DS,
1790                          SourceLocation IdLoc,
1791                          SourceLocation LParenLoc,
1792                          Expr **Args, unsigned NumArgs,
1793                          SourceLocation RParenLoc,
1794                          SourceLocation EllipsisLoc) {
1795  Expr *List = new (Context) ParenListExpr(Context, LParenLoc, Args, NumArgs,
1796                                           RParenLoc);
1797  return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
1798                             DS, IdLoc, List, EllipsisLoc);
1799}
1800
1801namespace {
1802
1803// Callback to only accept typo corrections that can be a valid C++ member
1804// intializer: either a non-static field member or a base class.
1805class MemInitializerValidatorCCC : public CorrectionCandidateCallback {
1806 public:
1807  explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
1808      : ClassDecl(ClassDecl) {}
1809
1810  virtual bool ValidateCandidate(const TypoCorrection &candidate) {
1811    if (NamedDecl *ND = candidate.getCorrectionDecl()) {
1812      if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
1813        return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
1814      else
1815        return isa<TypeDecl>(ND);
1816    }
1817    return false;
1818  }
1819
1820 private:
1821  CXXRecordDecl *ClassDecl;
1822};
1823
1824}
1825
1826/// \brief Handle a C++ member initializer.
1827MemInitResult
1828Sema::BuildMemInitializer(Decl *ConstructorD,
1829                          Scope *S,
1830                          CXXScopeSpec &SS,
1831                          IdentifierInfo *MemberOrBase,
1832                          ParsedType TemplateTypeTy,
1833                          const DeclSpec &DS,
1834                          SourceLocation IdLoc,
1835                          Expr *Init,
1836                          SourceLocation EllipsisLoc) {
1837  if (!ConstructorD)
1838    return true;
1839
1840  AdjustDeclIfTemplate(ConstructorD);
1841
1842  CXXConstructorDecl *Constructor
1843    = dyn_cast<CXXConstructorDecl>(ConstructorD);
1844  if (!Constructor) {
1845    // The user wrote a constructor initializer on a function that is
1846    // not a C++ constructor. Ignore the error for now, because we may
1847    // have more member initializers coming; we'll diagnose it just
1848    // once in ActOnMemInitializers.
1849    return true;
1850  }
1851
1852  CXXRecordDecl *ClassDecl = Constructor->getParent();
1853
1854  // C++ [class.base.init]p2:
1855  //   Names in a mem-initializer-id are looked up in the scope of the
1856  //   constructor's class and, if not found in that scope, are looked
1857  //   up in the scope containing the constructor's definition.
1858  //   [Note: if the constructor's class contains a member with the
1859  //   same name as a direct or virtual base class of the class, a
1860  //   mem-initializer-id naming the member or base class and composed
1861  //   of a single identifier refers to the class member. A
1862  //   mem-initializer-id for the hidden base class may be specified
1863  //   using a qualified name. ]
1864  if (!SS.getScopeRep() && !TemplateTypeTy) {
1865    // Look for a member, first.
1866    DeclContext::lookup_result Result
1867      = ClassDecl->lookup(MemberOrBase);
1868    if (Result.first != Result.second) {
1869      ValueDecl *Member;
1870      if ((Member = dyn_cast<FieldDecl>(*Result.first)) ||
1871          (Member = dyn_cast<IndirectFieldDecl>(*Result.first))) {
1872        if (EllipsisLoc.isValid())
1873          Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
1874            << MemberOrBase
1875            << SourceRange(IdLoc, Init->getSourceRange().getEnd());
1876
1877        return BuildMemberInitializer(Member, Init, IdLoc);
1878      }
1879    }
1880  }
1881  // It didn't name a member, so see if it names a class.
1882  QualType BaseType;
1883  TypeSourceInfo *TInfo = 0;
1884
1885  if (TemplateTypeTy) {
1886    BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
1887  } else if (DS.getTypeSpecType() == TST_decltype) {
1888    BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
1889  } else {
1890    LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
1891    LookupParsedName(R, S, &SS);
1892
1893    TypeDecl *TyD = R.getAsSingle<TypeDecl>();
1894    if (!TyD) {
1895      if (R.isAmbiguous()) return true;
1896
1897      // We don't want access-control diagnostics here.
1898      R.suppressDiagnostics();
1899
1900      if (SS.isSet() && isDependentScopeSpecifier(SS)) {
1901        bool NotUnknownSpecialization = false;
1902        DeclContext *DC = computeDeclContext(SS, false);
1903        if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
1904          NotUnknownSpecialization = !Record->hasAnyDependentBases();
1905
1906        if (!NotUnknownSpecialization) {
1907          // When the scope specifier can refer to a member of an unknown
1908          // specialization, we take it as a type name.
1909          BaseType = CheckTypenameType(ETK_None, SourceLocation(),
1910                                       SS.getWithLocInContext(Context),
1911                                       *MemberOrBase, IdLoc);
1912          if (BaseType.isNull())
1913            return true;
1914
1915          R.clear();
1916          R.setLookupName(MemberOrBase);
1917        }
1918      }
1919
1920      // If no results were found, try to correct typos.
1921      TypoCorrection Corr;
1922      MemInitializerValidatorCCC Validator(ClassDecl);
1923      if (R.empty() && BaseType.isNull() &&
1924          (Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
1925                              Validator, ClassDecl))) {
1926        std::string CorrectedStr(Corr.getAsString(getLangOpts()));
1927        std::string CorrectedQuotedStr(Corr.getQuoted(getLangOpts()));
1928        if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
1929          // We have found a non-static data member with a similar
1930          // name to what was typed; complain and initialize that
1931          // member.
1932          Diag(R.getNameLoc(), diag::err_mem_init_not_member_or_class_suggest)
1933            << MemberOrBase << true << CorrectedQuotedStr
1934            << FixItHint::CreateReplacement(R.getNameLoc(), CorrectedStr);
1935          Diag(Member->getLocation(), diag::note_previous_decl)
1936            << CorrectedQuotedStr;
1937
1938          return BuildMemberInitializer(Member, Init, IdLoc);
1939        } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
1940          const CXXBaseSpecifier *DirectBaseSpec;
1941          const CXXBaseSpecifier *VirtualBaseSpec;
1942          if (FindBaseInitializer(*this, ClassDecl,
1943                                  Context.getTypeDeclType(Type),
1944                                  DirectBaseSpec, VirtualBaseSpec)) {
1945            // We have found a direct or virtual base class with a
1946            // similar name to what was typed; complain and initialize
1947            // that base class.
1948            Diag(R.getNameLoc(), diag::err_mem_init_not_member_or_class_suggest)
1949              << MemberOrBase << false << CorrectedQuotedStr
1950              << FixItHint::CreateReplacement(R.getNameLoc(), CorrectedStr);
1951
1952            const CXXBaseSpecifier *BaseSpec = DirectBaseSpec? DirectBaseSpec
1953                                                             : VirtualBaseSpec;
1954            Diag(BaseSpec->getLocStart(),
1955                 diag::note_base_class_specified_here)
1956              << BaseSpec->getType()
1957              << BaseSpec->getSourceRange();
1958
1959            TyD = Type;
1960          }
1961        }
1962      }
1963
1964      if (!TyD && BaseType.isNull()) {
1965        Diag(IdLoc, diag::err_mem_init_not_member_or_class)
1966          << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
1967        return true;
1968      }
1969    }
1970
1971    if (BaseType.isNull()) {
1972      BaseType = Context.getTypeDeclType(TyD);
1973      if (SS.isSet()) {
1974        NestedNameSpecifier *Qualifier =
1975          static_cast<NestedNameSpecifier*>(SS.getScopeRep());
1976
1977        // FIXME: preserve source range information
1978        BaseType = Context.getElaboratedType(ETK_None, Qualifier, BaseType);
1979      }
1980    }
1981  }
1982
1983  if (!TInfo)
1984    TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
1985
1986  return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
1987}
1988
1989/// Checks a member initializer expression for cases where reference (or
1990/// pointer) members are bound to by-value parameters (or their addresses).
1991static void CheckForDanglingReferenceOrPointer(Sema &S, ValueDecl *Member,
1992                                               Expr *Init,
1993                                               SourceLocation IdLoc) {
1994  QualType MemberTy = Member->getType();
1995
1996  // We only handle pointers and references currently.
1997  // FIXME: Would this be relevant for ObjC object pointers? Or block pointers?
1998  if (!MemberTy->isReferenceType() && !MemberTy->isPointerType())
1999    return;
2000
2001  const bool IsPointer = MemberTy->isPointerType();
2002  if (IsPointer) {
2003    if (const UnaryOperator *Op
2004          = dyn_cast<UnaryOperator>(Init->IgnoreParenImpCasts())) {
2005      // The only case we're worried about with pointers requires taking the
2006      // address.
2007      if (Op->getOpcode() != UO_AddrOf)
2008        return;
2009
2010      Init = Op->getSubExpr();
2011    } else {
2012      // We only handle address-of expression initializers for pointers.
2013      return;
2014    }
2015  }
2016
2017  if (isa<MaterializeTemporaryExpr>(Init->IgnoreParens())) {
2018    // Taking the address of a temporary will be diagnosed as a hard error.
2019    if (IsPointer)
2020      return;
2021
2022    S.Diag(Init->getExprLoc(), diag::warn_bind_ref_member_to_temporary)
2023      << Member << Init->getSourceRange();
2024  } else if (const DeclRefExpr *DRE
2025               = dyn_cast<DeclRefExpr>(Init->IgnoreParens())) {
2026    // We only warn when referring to a non-reference parameter declaration.
2027    const ParmVarDecl *Parameter = dyn_cast<ParmVarDecl>(DRE->getDecl());
2028    if (!Parameter || Parameter->getType()->isReferenceType())
2029      return;
2030
2031    S.Diag(Init->getExprLoc(),
2032           IsPointer ? diag::warn_init_ptr_member_to_parameter_addr
2033                     : diag::warn_bind_ref_member_to_parameter)
2034      << Member << Parameter << Init->getSourceRange();
2035  } else {
2036    // Other initializers are fine.
2037    return;
2038  }
2039
2040  S.Diag(Member->getLocation(), diag::note_ref_or_ptr_member_declared_here)
2041    << (unsigned)IsPointer;
2042}
2043
2044namespace {
2045  class UninitializedFieldVisitor
2046      : public EvaluatedExprVisitor<UninitializedFieldVisitor> {
2047    Sema &S;
2048    ValueDecl *VD;
2049  public:
2050    typedef EvaluatedExprVisitor<UninitializedFieldVisitor> Inherited;
2051    UninitializedFieldVisitor(Sema &S, ValueDecl *VD) : Inherited(S.Context),
2052                                                        S(S), VD(VD) {
2053    }
2054
2055    void HandleExpr(Expr *E) {
2056      if (!E) return;
2057
2058      // Expressions like x(x) sometimes lack the surrounding expressions
2059      // but need to be checked anyways.
2060      HandleValue(E);
2061      Visit(E);
2062    }
2063
2064    void HandleValue(Expr *E) {
2065      E = E->IgnoreParens();
2066
2067      if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
2068        if (isa<EnumConstantDecl>(ME->getMemberDecl()))
2069            return;
2070        Expr *Base = E;
2071        while (isa<MemberExpr>(Base)) {
2072          ME = dyn_cast<MemberExpr>(Base);
2073          if (VarDecl *VarD = dyn_cast<VarDecl>(ME->getMemberDecl()))
2074            if (VarD->hasGlobalStorage())
2075              return;
2076          Base = ME->getBase();
2077        }
2078
2079        if (VD == ME->getMemberDecl() && isa<CXXThisExpr>(Base)) {
2080          S.Diag(ME->getExprLoc(), diag::warn_field_is_uninit);
2081          return;
2082        }
2083      }
2084
2085      if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
2086        HandleValue(CO->getTrueExpr());
2087        HandleValue(CO->getFalseExpr());
2088        return;
2089      }
2090
2091      if (BinaryConditionalOperator *BCO =
2092              dyn_cast<BinaryConditionalOperator>(E)) {
2093        HandleValue(BCO->getCommon());
2094        HandleValue(BCO->getFalseExpr());
2095        return;
2096      }
2097
2098      if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
2099        switch (BO->getOpcode()) {
2100        default:
2101          return;
2102        case(BO_PtrMemD):
2103        case(BO_PtrMemI):
2104          HandleValue(BO->getLHS());
2105          return;
2106        case(BO_Comma):
2107          HandleValue(BO->getRHS());
2108          return;
2109        }
2110      }
2111    }
2112
2113    void VisitImplicitCastExpr(ImplicitCastExpr *E) {
2114      if (E->getCastKind() == CK_LValueToRValue)
2115        HandleValue(E->getSubExpr());
2116
2117      Inherited::VisitImplicitCastExpr(E);
2118    }
2119
2120    void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
2121      Expr *Callee = E->getCallee();
2122      if (isa<MemberExpr>(Callee))
2123        HandleValue(Callee);
2124
2125      Inherited::VisitCXXMemberCallExpr(E);
2126    }
2127  };
2128  static void CheckInitExprContainsUninitializedFields(Sema &S, Expr *E,
2129                                                       ValueDecl *VD) {
2130    UninitializedFieldVisitor(S, VD).HandleExpr(E);
2131  }
2132} // namespace
2133
2134MemInitResult
2135Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
2136                             SourceLocation IdLoc) {
2137  FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
2138  IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
2139  assert((DirectMember || IndirectMember) &&
2140         "Member must be a FieldDecl or IndirectFieldDecl");
2141
2142  if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
2143    return true;
2144
2145  if (Member->isInvalidDecl())
2146    return true;
2147
2148  // Diagnose value-uses of fields to initialize themselves, e.g.
2149  //   foo(foo)
2150  // where foo is not also a parameter to the constructor.
2151  // TODO: implement -Wuninitialized and fold this into that framework.
2152  Expr **Args;
2153  unsigned NumArgs;
2154  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
2155    Args = ParenList->getExprs();
2156    NumArgs = ParenList->getNumExprs();
2157  } else {
2158    InitListExpr *InitList = cast<InitListExpr>(Init);
2159    Args = InitList->getInits();
2160    NumArgs = InitList->getNumInits();
2161  }
2162
2163  // Mark FieldDecl as being used if it is a non-primitive type and the
2164  // initializer does not call the default constructor (which is trivial
2165  // for all entries in UnusedPrivateFields).
2166  // FIXME: Make this smarter once more side effect-free types can be
2167  // determined.
2168  if (NumArgs > 0) {
2169    if (Member->getType()->isRecordType()) {
2170      UnusedPrivateFields.remove(Member);
2171    } else {
2172      for (unsigned i = 0; i < NumArgs; ++i) {
2173        if (Args[i]->HasSideEffects(Context)) {
2174          UnusedPrivateFields.remove(Member);
2175          break;
2176        }
2177      }
2178    }
2179  }
2180
2181  if (getDiagnostics().getDiagnosticLevel(diag::warn_field_is_uninit, IdLoc)
2182        != DiagnosticsEngine::Ignored)
2183    for (unsigned i = 0; i < NumArgs; ++i)
2184      // FIXME: Warn about the case when other fields are used before being
2185      // uninitialized. For example, let this field be the i'th field. When
2186      // initializing the i'th field, throw a warning if any of the >= i'th
2187      // fields are used, as they are not yet initialized.
2188      // Right now we are only handling the case where the i'th field uses
2189      // itself in its initializer.
2190      CheckInitExprContainsUninitializedFields(*this, Args[i], Member);
2191
2192  SourceRange InitRange = Init->getSourceRange();
2193
2194  if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
2195    // Can't check initialization for a member of dependent type or when
2196    // any of the arguments are type-dependent expressions.
2197    DiscardCleanupsInEvaluationContext();
2198  } else {
2199    bool InitList = false;
2200    if (isa<InitListExpr>(Init)) {
2201      InitList = true;
2202      Args = &Init;
2203      NumArgs = 1;
2204
2205      if (isStdInitializerList(Member->getType(), 0)) {
2206        Diag(IdLoc, diag::warn_dangling_std_initializer_list)
2207            << /*at end of ctor*/1 << InitRange;
2208      }
2209    }
2210
2211    // Initialize the member.
2212    InitializedEntity MemberEntity =
2213      DirectMember ? InitializedEntity::InitializeMember(DirectMember, 0)
2214                   : InitializedEntity::InitializeMember(IndirectMember, 0);
2215    InitializationKind Kind =
2216      InitList ? InitializationKind::CreateDirectList(IdLoc)
2217               : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
2218                                                  InitRange.getEnd());
2219
2220    InitializationSequence InitSeq(*this, MemberEntity, Kind, Args, NumArgs);
2221    ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind,
2222                                            MultiExprArg(*this, Args, NumArgs),
2223                                            0);
2224    if (MemberInit.isInvalid())
2225      return true;
2226
2227    CheckImplicitConversions(MemberInit.get(),
2228                             InitRange.getBegin());
2229
2230    // C++0x [class.base.init]p7:
2231    //   The initialization of each base and member constitutes a
2232    //   full-expression.
2233    MemberInit = MaybeCreateExprWithCleanups(MemberInit);
2234    if (MemberInit.isInvalid())
2235      return true;
2236
2237    // If we are in a dependent context, template instantiation will
2238    // perform this type-checking again. Just save the arguments that we
2239    // received.
2240    // FIXME: This isn't quite ideal, since our ASTs don't capture all
2241    // of the information that we have about the member
2242    // initializer. However, deconstructing the ASTs is a dicey process,
2243    // and this approach is far more likely to get the corner cases right.
2244    if (CurContext->isDependentContext()) {
2245      // The existing Init will do fine.
2246    } else {
2247      Init = MemberInit.get();
2248      CheckForDanglingReferenceOrPointer(*this, Member, Init, IdLoc);
2249    }
2250  }
2251
2252  if (DirectMember) {
2253    return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
2254                                            InitRange.getBegin(), Init,
2255                                            InitRange.getEnd());
2256  } else {
2257    return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
2258                                            InitRange.getBegin(), Init,
2259                                            InitRange.getEnd());
2260  }
2261}
2262
2263MemInitResult
2264Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
2265                                 CXXRecordDecl *ClassDecl) {
2266  SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
2267  if (!LangOpts.CPlusPlus0x)
2268    return Diag(NameLoc, diag::err_delegating_ctor)
2269      << TInfo->getTypeLoc().getLocalSourceRange();
2270  Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
2271
2272  bool InitList = true;
2273  Expr **Args = &Init;
2274  unsigned NumArgs = 1;
2275  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
2276    InitList = false;
2277    Args = ParenList->getExprs();
2278    NumArgs = ParenList->getNumExprs();
2279  }
2280
2281  SourceRange InitRange = Init->getSourceRange();
2282  // Initialize the object.
2283  InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation(
2284                                     QualType(ClassDecl->getTypeForDecl(), 0));
2285  InitializationKind Kind =
2286    InitList ? InitializationKind::CreateDirectList(NameLoc)
2287             : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
2288                                                InitRange.getEnd());
2289  InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args, NumArgs);
2290  ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
2291                                              MultiExprArg(*this, Args,NumArgs),
2292                                              0);
2293  if (DelegationInit.isInvalid())
2294    return true;
2295
2296  assert(cast<CXXConstructExpr>(DelegationInit.get())->getConstructor() &&
2297         "Delegating constructor with no target?");
2298
2299  CheckImplicitConversions(DelegationInit.get(), InitRange.getBegin());
2300
2301  // C++0x [class.base.init]p7:
2302  //   The initialization of each base and member constitutes a
2303  //   full-expression.
2304  DelegationInit = MaybeCreateExprWithCleanups(DelegationInit);
2305  if (DelegationInit.isInvalid())
2306    return true;
2307
2308  // If we are in a dependent context, template instantiation will
2309  // perform this type-checking again. Just save the arguments that we
2310  // received in a ParenListExpr.
2311  // FIXME: This isn't quite ideal, since our ASTs don't capture all
2312  // of the information that we have about the base
2313  // initializer. However, deconstructing the ASTs is a dicey process,
2314  // and this approach is far more likely to get the corner cases right.
2315  if (CurContext->isDependentContext())
2316    DelegationInit = Owned(Init);
2317
2318  return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
2319                                          DelegationInit.takeAs<Expr>(),
2320                                          InitRange.getEnd());
2321}
2322
2323MemInitResult
2324Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
2325                           Expr *Init, CXXRecordDecl *ClassDecl,
2326                           SourceLocation EllipsisLoc) {
2327  SourceLocation BaseLoc
2328    = BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();
2329
2330  if (!BaseType->isDependentType() && !BaseType->isRecordType())
2331    return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
2332             << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
2333
2334  // C++ [class.base.init]p2:
2335  //   [...] Unless the mem-initializer-id names a nonstatic data
2336  //   member of the constructor's class or a direct or virtual base
2337  //   of that class, the mem-initializer is ill-formed. A
2338  //   mem-initializer-list can initialize a base class using any
2339  //   name that denotes that base class type.
2340  bool Dependent = BaseType->isDependentType() || Init->isTypeDependent();
2341
2342  SourceRange InitRange = Init->getSourceRange();
2343  if (EllipsisLoc.isValid()) {
2344    // This is a pack expansion.
2345    if (!BaseType->containsUnexpandedParameterPack())  {
2346      Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
2347        << SourceRange(BaseLoc, InitRange.getEnd());
2348
2349      EllipsisLoc = SourceLocation();
2350    }
2351  } else {
2352    // Check for any unexpanded parameter packs.
2353    if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
2354      return true;
2355
2356    if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
2357      return true;
2358  }
2359
2360  // Check for direct and virtual base classes.
2361  const CXXBaseSpecifier *DirectBaseSpec = 0;
2362  const CXXBaseSpecifier *VirtualBaseSpec = 0;
2363  if (!Dependent) {
2364    if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
2365                                       BaseType))
2366      return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);
2367
2368    FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
2369                        VirtualBaseSpec);
2370
2371    // C++ [base.class.init]p2:
2372    // Unless the mem-initializer-id names a nonstatic data member of the
2373    // constructor's class or a direct or virtual base of that class, the
2374    // mem-initializer is ill-formed.
2375    if (!DirectBaseSpec && !VirtualBaseSpec) {
2376      // If the class has any dependent bases, then it's possible that
2377      // one of those types will resolve to the same type as
2378      // BaseType. Therefore, just treat this as a dependent base
2379      // class initialization.  FIXME: Should we try to check the
2380      // initialization anyway? It seems odd.
2381      if (ClassDecl->hasAnyDependentBases())
2382        Dependent = true;
2383      else
2384        return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
2385          << BaseType << Context.getTypeDeclType(ClassDecl)
2386          << BaseTInfo->getTypeLoc().getLocalSourceRange();
2387    }
2388  }
2389
2390  if (Dependent) {
2391    DiscardCleanupsInEvaluationContext();
2392
2393    return new (Context) CXXCtorInitializer(Context, BaseTInfo,
2394                                            /*IsVirtual=*/false,
2395                                            InitRange.getBegin(), Init,
2396                                            InitRange.getEnd(), EllipsisLoc);
2397  }
2398
2399  // C++ [base.class.init]p2:
2400  //   If a mem-initializer-id is ambiguous because it designates both
2401  //   a direct non-virtual base class and an inherited virtual base
2402  //   class, the mem-initializer is ill-formed.
2403  if (DirectBaseSpec && VirtualBaseSpec)
2404    return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
2405      << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
2406
2407  CXXBaseSpecifier *BaseSpec = const_cast<CXXBaseSpecifier *>(DirectBaseSpec);
2408  if (!BaseSpec)
2409    BaseSpec = const_cast<CXXBaseSpecifier *>(VirtualBaseSpec);
2410
2411  // Initialize the base.
2412  bool InitList = true;
2413  Expr **Args = &Init;
2414  unsigned NumArgs = 1;
2415  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
2416    InitList = false;
2417    Args = ParenList->getExprs();
2418    NumArgs = ParenList->getNumExprs();
2419  }
2420
2421  InitializedEntity BaseEntity =
2422    InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
2423  InitializationKind Kind =
2424    InitList ? InitializationKind::CreateDirectList(BaseLoc)
2425             : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
2426                                                InitRange.getEnd());
2427  InitializationSequence InitSeq(*this, BaseEntity, Kind, Args, NumArgs);
2428  ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind,
2429                                          MultiExprArg(*this, Args, NumArgs),
2430                                          0);
2431  if (BaseInit.isInvalid())
2432    return true;
2433
2434  CheckImplicitConversions(BaseInit.get(), InitRange.getBegin());
2435
2436  // C++0x [class.base.init]p7:
2437  //   The initialization of each base and member constitutes a
2438  //   full-expression.
2439  BaseInit = MaybeCreateExprWithCleanups(BaseInit);
2440  if (BaseInit.isInvalid())
2441    return true;
2442
2443  // If we are in a dependent context, template instantiation will
2444  // perform this type-checking again. Just save the arguments that we
2445  // received in a ParenListExpr.
2446  // FIXME: This isn't quite ideal, since our ASTs don't capture all
2447  // of the information that we have about the base
2448  // initializer. However, deconstructing the ASTs is a dicey process,
2449  // and this approach is far more likely to get the corner cases right.
2450  if (CurContext->isDependentContext())
2451    BaseInit = Owned(Init);
2452
2453  return new (Context) CXXCtorInitializer(Context, BaseTInfo,
2454                                          BaseSpec->isVirtual(),
2455                                          InitRange.getBegin(),
2456                                          BaseInit.takeAs<Expr>(),
2457                                          InitRange.getEnd(), EllipsisLoc);
2458}
2459
2460// Create a static_cast\<T&&>(expr).
2461static Expr *CastForMoving(Sema &SemaRef, Expr *E) {
2462  QualType ExprType = E->getType();
2463  QualType TargetType = SemaRef.Context.getRValueReferenceType(ExprType);
2464  SourceLocation ExprLoc = E->getLocStart();
2465  TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
2466      TargetType, ExprLoc);
2467
2468  return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
2469                                   SourceRange(ExprLoc, ExprLoc),
2470                                   E->getSourceRange()).take();
2471}
2472
2473/// ImplicitInitializerKind - How an implicit base or member initializer should
2474/// initialize its base or member.
2475enum ImplicitInitializerKind {
2476  IIK_Default,
2477  IIK_Copy,
2478  IIK_Move
2479};
2480
2481static bool
2482BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
2483                             ImplicitInitializerKind ImplicitInitKind,
2484                             CXXBaseSpecifier *BaseSpec,
2485                             bool IsInheritedVirtualBase,
2486                             CXXCtorInitializer *&CXXBaseInit) {
2487  InitializedEntity InitEntity
2488    = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
2489                                        IsInheritedVirtualBase);
2490
2491  ExprResult BaseInit;
2492
2493  switch (ImplicitInitKind) {
2494  case IIK_Default: {
2495    InitializationKind InitKind
2496      = InitializationKind::CreateDefault(Constructor->getLocation());
2497    InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, 0, 0);
2498    BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind,
2499                               MultiExprArg(SemaRef, 0, 0));
2500    break;
2501  }
2502
2503  case IIK_Move:
2504  case IIK_Copy: {
2505    bool Moving = ImplicitInitKind == IIK_Move;
2506    ParmVarDecl *Param = Constructor->getParamDecl(0);
2507    QualType ParamType = Param->getType().getNonReferenceType();
2508
2509    Expr *CopyCtorArg =
2510      DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
2511                          SourceLocation(), Param, false,
2512                          Constructor->getLocation(), ParamType,
2513                          VK_LValue, 0);
2514
2515    SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));
2516
2517    // Cast to the base class to avoid ambiguities.
2518    QualType ArgTy =
2519      SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
2520                                       ParamType.getQualifiers());
2521
2522    if (Moving) {
2523      CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
2524    }
2525
2526    CXXCastPath BasePath;
2527    BasePath.push_back(BaseSpec);
2528    CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
2529                                            CK_UncheckedDerivedToBase,
2530                                            Moving ? VK_XValue : VK_LValue,
2531                                            &BasePath).take();
2532
2533    InitializationKind InitKind
2534      = InitializationKind::CreateDirect(Constructor->getLocation(),
2535                                         SourceLocation(), SourceLocation());
2536    InitializationSequence InitSeq(SemaRef, InitEntity, InitKind,
2537                                   &CopyCtorArg, 1);
2538    BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind,
2539                               MultiExprArg(&CopyCtorArg, 1));
2540    break;
2541  }
2542  }
2543
2544  BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
2545  if (BaseInit.isInvalid())
2546    return true;
2547
2548  CXXBaseInit =
2549    new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
2550               SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
2551                                                        SourceLocation()),
2552                                             BaseSpec->isVirtual(),
2553                                             SourceLocation(),
2554                                             BaseInit.takeAs<Expr>(),
2555                                             SourceLocation(),
2556                                             SourceLocation());
2557
2558  return false;
2559}
2560
2561static bool RefersToRValueRef(Expr *MemRef) {
2562  ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
2563  return Referenced->getType()->isRValueReferenceType();
2564}
2565
2566static bool
2567BuildImplicitMemberInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
2568                               ImplicitInitializerKind ImplicitInitKind,
2569                               FieldDecl *Field, IndirectFieldDecl *Indirect,
2570                               CXXCtorInitializer *&CXXMemberInit) {
2571  if (Field->isInvalidDecl())
2572    return true;
2573
2574  SourceLocation Loc = Constructor->getLocation();
2575
2576  if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
2577    bool Moving = ImplicitInitKind == IIK_Move;
2578    ParmVarDecl *Param = Constructor->getParamDecl(0);
2579    QualType ParamType = Param->getType().getNonReferenceType();
2580
2581    // Suppress copying zero-width bitfields.
2582    if (Field->isBitField() && Field->getBitWidthValue(SemaRef.Context) == 0)
2583      return false;
2584
2585    Expr *MemberExprBase =
2586      DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
2587                          SourceLocation(), Param, false,
2588                          Loc, ParamType, VK_LValue, 0);
2589
2590    SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));
2591
2592    if (Moving) {
2593      MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
2594    }
2595
2596    // Build a reference to this field within the parameter.
2597    CXXScopeSpec SS;
2598    LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
2599                              Sema::LookupMemberName);
2600    MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
2601                                  : cast<ValueDecl>(Field), AS_public);
2602    MemberLookup.resolveKind();
2603    ExprResult CtorArg
2604      = SemaRef.BuildMemberReferenceExpr(MemberExprBase,
2605                                         ParamType, Loc,
2606                                         /*IsArrow=*/false,
2607                                         SS,
2608                                         /*TemplateKWLoc=*/SourceLocation(),
2609                                         /*FirstQualifierInScope=*/0,
2610                                         MemberLookup,
2611                                         /*TemplateArgs=*/0);
2612    if (CtorArg.isInvalid())
2613      return true;
2614
2615    // C++11 [class.copy]p15:
2616    //   - if a member m has rvalue reference type T&&, it is direct-initialized
2617    //     with static_cast<T&&>(x.m);
2618    if (RefersToRValueRef(CtorArg.get())) {
2619      CtorArg = CastForMoving(SemaRef, CtorArg.take());
2620    }
2621
2622    // When the field we are copying is an array, create index variables for
2623    // each dimension of the array. We use these index variables to subscript
2624    // the source array, and other clients (e.g., CodeGen) will perform the
2625    // necessary iteration with these index variables.
2626    SmallVector<VarDecl *, 4> IndexVariables;
2627    QualType BaseType = Field->getType();
2628    QualType SizeType = SemaRef.Context.getSizeType();
2629    bool InitializingArray = false;
2630    while (const ConstantArrayType *Array
2631                          = SemaRef.Context.getAsConstantArrayType(BaseType)) {
2632      InitializingArray = true;
2633      // Create the iteration variable for this array index.
2634      IdentifierInfo *IterationVarName = 0;
2635      {
2636        SmallString<8> Str;
2637        llvm::raw_svector_ostream OS(Str);
2638        OS << "__i" << IndexVariables.size();
2639        IterationVarName = &SemaRef.Context.Idents.get(OS.str());
2640      }
2641      VarDecl *IterationVar
2642        = VarDecl::Create(SemaRef.Context, SemaRef.CurContext, Loc, Loc,
2643                          IterationVarName, SizeType,
2644                        SemaRef.Context.getTrivialTypeSourceInfo(SizeType, Loc),
2645                          SC_None, SC_None);
2646      IndexVariables.push_back(IterationVar);
2647
2648      // Create a reference to the iteration variable.
2649      ExprResult IterationVarRef
2650        = SemaRef.BuildDeclRefExpr(IterationVar, SizeType, VK_LValue, Loc);
2651      assert(!IterationVarRef.isInvalid() &&
2652             "Reference to invented variable cannot fail!");
2653      IterationVarRef = SemaRef.DefaultLvalueConversion(IterationVarRef.take());
2654      assert(!IterationVarRef.isInvalid() &&
2655             "Conversion of invented variable cannot fail!");
2656
2657      // Subscript the array with this iteration variable.
2658      CtorArg = SemaRef.CreateBuiltinArraySubscriptExpr(CtorArg.take(), Loc,
2659                                                        IterationVarRef.take(),
2660                                                        Loc);
2661      if (CtorArg.isInvalid())
2662        return true;
2663
2664      BaseType = Array->getElementType();
2665    }
2666
2667    // The array subscript expression is an lvalue, which is wrong for moving.
2668    if (Moving && InitializingArray)
2669      CtorArg = CastForMoving(SemaRef, CtorArg.take());
2670
2671    // Construct the entity that we will be initializing. For an array, this
2672    // will be first element in the array, which may require several levels
2673    // of array-subscript entities.
2674    SmallVector<InitializedEntity, 4> Entities;
2675    Entities.reserve(1 + IndexVariables.size());
2676    if (Indirect)
2677      Entities.push_back(InitializedEntity::InitializeMember(Indirect));
2678    else
2679      Entities.push_back(InitializedEntity::InitializeMember(Field));
2680    for (unsigned I = 0, N = IndexVariables.size(); I != N; ++I)
2681      Entities.push_back(InitializedEntity::InitializeElement(SemaRef.Context,
2682                                                              0,
2683                                                              Entities.back()));
2684
2685    // Direct-initialize to use the copy constructor.
2686    InitializationKind InitKind =
2687      InitializationKind::CreateDirect(Loc, SourceLocation(), SourceLocation());
2688
2689    Expr *CtorArgE = CtorArg.takeAs<Expr>();
2690    InitializationSequence InitSeq(SemaRef, Entities.back(), InitKind,
2691                                   &CtorArgE, 1);
2692
2693    ExprResult MemberInit
2694      = InitSeq.Perform(SemaRef, Entities.back(), InitKind,
2695                        MultiExprArg(&CtorArgE, 1));
2696    MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
2697    if (MemberInit.isInvalid())
2698      return true;
2699
2700    if (Indirect) {
2701      assert(IndexVariables.size() == 0 &&
2702             "Indirect field improperly initialized");
2703      CXXMemberInit
2704        = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Indirect,
2705                                                   Loc, Loc,
2706                                                   MemberInit.takeAs<Expr>(),
2707                                                   Loc);
2708    } else
2709      CXXMemberInit = CXXCtorInitializer::Create(SemaRef.Context, Field, Loc,
2710                                                 Loc, MemberInit.takeAs<Expr>(),
2711                                                 Loc,
2712                                                 IndexVariables.data(),
2713                                                 IndexVariables.size());
2714    return false;
2715  }
2716
2717  assert(ImplicitInitKind == IIK_Default && "Unhandled implicit init kind!");
2718
2719  QualType FieldBaseElementType =
2720    SemaRef.Context.getBaseElementType(Field->getType());
2721
2722  if (FieldBaseElementType->isRecordType()) {
2723    InitializedEntity InitEntity
2724      = Indirect? InitializedEntity::InitializeMember(Indirect)
2725                : InitializedEntity::InitializeMember(Field);
2726    InitializationKind InitKind =
2727      InitializationKind::CreateDefault(Loc);
2728
2729    InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, 0, 0);
2730    ExprResult MemberInit =
2731      InitSeq.Perform(SemaRef, InitEntity, InitKind, MultiExprArg());
2732
2733    MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
2734    if (MemberInit.isInvalid())
2735      return true;
2736
2737    if (Indirect)
2738      CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
2739                                                               Indirect, Loc,
2740                                                               Loc,
2741                                                               MemberInit.get(),
2742                                                               Loc);
2743    else
2744      CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
2745                                                               Field, Loc, Loc,
2746                                                               MemberInit.get(),
2747                                                               Loc);
2748    return false;
2749  }
2750
2751  if (!Field->getParent()->isUnion()) {
2752    if (FieldBaseElementType->isReferenceType()) {
2753      SemaRef.Diag(Constructor->getLocation(),
2754                   diag::err_uninitialized_member_in_ctor)
2755      << (int)Constructor->isImplicit()
2756      << SemaRef.Context.getTagDeclType(Constructor->getParent())
2757      << 0 << Field->getDeclName();
2758      SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
2759      return true;
2760    }
2761
2762    if (FieldBaseElementType.isConstQualified()) {
2763      SemaRef.Diag(Constructor->getLocation(),
2764                   diag::err_uninitialized_member_in_ctor)
2765      << (int)Constructor->isImplicit()
2766      << SemaRef.Context.getTagDeclType(Constructor->getParent())
2767      << 1 << Field->getDeclName();
2768      SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
2769      return true;
2770    }
2771  }
2772
2773  if (SemaRef.getLangOpts().ObjCAutoRefCount &&
2774      FieldBaseElementType->isObjCRetainableType() &&
2775      FieldBaseElementType.getObjCLifetime() != Qualifiers::OCL_None &&
2776      FieldBaseElementType.getObjCLifetime() != Qualifiers::OCL_ExplicitNone) {
2777    // ARC:
2778    //   Default-initialize Objective-C pointers to NULL.
2779    CXXMemberInit
2780      = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
2781                                                 Loc, Loc,
2782                 new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
2783                                                 Loc);
2784    return false;
2785  }
2786
2787  // Nothing to initialize.
2788  CXXMemberInit = 0;
2789  return false;
2790}
2791
2792namespace {
2793struct BaseAndFieldInfo {
2794  Sema &S;
2795  CXXConstructorDecl *Ctor;
2796  bool AnyErrorsInInits;
2797  ImplicitInitializerKind IIK;
2798  llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
2799  SmallVector<CXXCtorInitializer*, 8> AllToInit;
2800
2801  BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
2802    : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
2803    bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
2804    if (Generated && Ctor->isCopyConstructor())
2805      IIK = IIK_Copy;
2806    else if (Generated && Ctor->isMoveConstructor())
2807      IIK = IIK_Move;
2808    else
2809      IIK = IIK_Default;
2810  }
2811
2812  bool isImplicitCopyOrMove() const {
2813    switch (IIK) {
2814    case IIK_Copy:
2815    case IIK_Move:
2816      return true;
2817
2818    case IIK_Default:
2819      return false;
2820    }
2821
2822    llvm_unreachable("Invalid ImplicitInitializerKind!");
2823  }
2824};
2825}
2826
2827/// \brief Determine whether the given indirect field declaration is somewhere
2828/// within an anonymous union.
2829static bool isWithinAnonymousUnion(IndirectFieldDecl *F) {
2830  for (IndirectFieldDecl::chain_iterator C = F->chain_begin(),
2831                                      CEnd = F->chain_end();
2832       C != CEnd; ++C)
2833    if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>((*C)->getDeclContext()))
2834      if (Record->isUnion())
2835        return true;
2836
2837  return false;
2838}
2839
2840/// \brief Determine whether the given type is an incomplete or zero-lenfgth
2841/// array type.
2842static bool isIncompleteOrZeroLengthArrayType(ASTContext &Context, QualType T) {
2843  if (T->isIncompleteArrayType())
2844    return true;
2845
2846  while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
2847    if (!ArrayT->getSize())
2848      return true;
2849
2850    T = ArrayT->getElementType();
2851  }
2852
2853  return false;
2854}
2855
2856static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
2857                                    FieldDecl *Field,
2858                                    IndirectFieldDecl *Indirect = 0) {
2859
2860  // Overwhelmingly common case: we have a direct initializer for this field.
2861  if (CXXCtorInitializer *Init = Info.AllBaseFields.lookup(Field)) {
2862    Info.AllToInit.push_back(Init);
2863    return false;
2864  }
2865
2866  // C++0x [class.base.init]p8: if the entity is a non-static data member that
2867  // has a brace-or-equal-initializer, the entity is initialized as specified
2868  // in [dcl.init].
2869  if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
2870    CXXCtorInitializer *Init;
2871    if (Indirect)
2872      Init = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Indirect,
2873                                                      SourceLocation(),
2874                                                      SourceLocation(), 0,
2875                                                      SourceLocation());
2876    else
2877      Init = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
2878                                                      SourceLocation(),
2879                                                      SourceLocation(), 0,
2880                                                      SourceLocation());
2881    Info.AllToInit.push_back(Init);
2882
2883    // Check whether this initializer makes the field "used".
2884    Expr *InitExpr = Field->getInClassInitializer();
2885    if (Field->getType()->isRecordType() ||
2886        (InitExpr && InitExpr->HasSideEffects(SemaRef.Context)))
2887      SemaRef.UnusedPrivateFields.remove(Field);
2888
2889    return false;
2890  }
2891
2892  // Don't build an implicit initializer for union members if none was
2893  // explicitly specified.
2894  if (Field->getParent()->isUnion() ||
2895      (Indirect && isWithinAnonymousUnion(Indirect)))
2896    return false;
2897
2898  // Don't initialize incomplete or zero-length arrays.
2899  if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
2900    return false;
2901
2902  // Don't try to build an implicit initializer if there were semantic
2903  // errors in any of the initializers (and therefore we might be
2904  // missing some that the user actually wrote).
2905  if (Info.AnyErrorsInInits || Field->isInvalidDecl())
2906    return false;
2907
2908  CXXCtorInitializer *Init = 0;
2909  if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
2910                                     Indirect, Init))
2911    return true;
2912
2913  if (Init)
2914    Info.AllToInit.push_back(Init);
2915
2916  return false;
2917}
2918
2919bool
2920Sema::SetDelegatingInitializer(CXXConstructorDecl *Constructor,
2921                               CXXCtorInitializer *Initializer) {
2922  assert(Initializer->isDelegatingInitializer());
2923  Constructor->setNumCtorInitializers(1);
2924  CXXCtorInitializer **initializer =
2925    new (Context) CXXCtorInitializer*[1];
2926  memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
2927  Constructor->setCtorInitializers(initializer);
2928
2929  if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
2930    MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
2931    DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
2932  }
2933
2934  DelegatingCtorDecls.push_back(Constructor);
2935
2936  return false;
2937}
2938
2939bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor,
2940                               CXXCtorInitializer **Initializers,
2941                               unsigned NumInitializers,
2942                               bool AnyErrors) {
2943  if (Constructor->isDependentContext()) {
2944    // Just store the initializers as written, they will be checked during
2945    // instantiation.
2946    if (NumInitializers > 0) {
2947      Constructor->setNumCtorInitializers(NumInitializers);
2948      CXXCtorInitializer **baseOrMemberInitializers =
2949        new (Context) CXXCtorInitializer*[NumInitializers];
2950      memcpy(baseOrMemberInitializers, Initializers,
2951             NumInitializers * sizeof(CXXCtorInitializer*));
2952      Constructor->setCtorInitializers(baseOrMemberInitializers);
2953    }
2954
2955    return false;
2956  }
2957
2958  BaseAndFieldInfo Info(*this, Constructor, AnyErrors);
2959
2960  // We need to build the initializer AST according to order of construction
2961  // and not what user specified in the Initializers list.
2962  CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
2963  if (!ClassDecl)
2964    return true;
2965
2966  bool HadError = false;
2967
2968  for (unsigned i = 0; i < NumInitializers; i++) {
2969    CXXCtorInitializer *Member = Initializers[i];
2970
2971    if (Member->isBaseInitializer())
2972      Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
2973    else
2974      Info.AllBaseFields[Member->getAnyMember()] = Member;
2975  }
2976
2977  // Keep track of the direct virtual bases.
2978  llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
2979  for (CXXRecordDecl::base_class_iterator I = ClassDecl->bases_begin(),
2980       E = ClassDecl->bases_end(); I != E; ++I) {
2981    if (I->isVirtual())
2982      DirectVBases.insert(I);
2983  }
2984
2985  // Push virtual bases before others.
2986  for (CXXRecordDecl::base_class_iterator VBase = ClassDecl->vbases_begin(),
2987       E = ClassDecl->vbases_end(); VBase != E; ++VBase) {
2988
2989    if (CXXCtorInitializer *Value
2990        = Info.AllBaseFields.lookup(VBase->getType()->getAs<RecordType>())) {
2991      Info.AllToInit.push_back(Value);
2992    } else if (!AnyErrors) {
2993      bool IsInheritedVirtualBase = !DirectVBases.count(VBase);
2994      CXXCtorInitializer *CXXBaseInit;
2995      if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
2996                                       VBase, IsInheritedVirtualBase,
2997                                       CXXBaseInit)) {
2998        HadError = true;
2999        continue;
3000      }
3001
3002      Info.AllToInit.push_back(CXXBaseInit);
3003    }
3004  }
3005
3006  // Non-virtual bases.
3007  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
3008       E = ClassDecl->bases_end(); Base != E; ++Base) {
3009    // Virtuals are in the virtual base list and already constructed.
3010    if (Base->isVirtual())
3011      continue;
3012
3013    if (CXXCtorInitializer *Value
3014          = Info.AllBaseFields.lookup(Base->getType()->getAs<RecordType>())) {
3015      Info.AllToInit.push_back(Value);
3016    } else if (!AnyErrors) {
3017      CXXCtorInitializer *CXXBaseInit;
3018      if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
3019                                       Base, /*IsInheritedVirtualBase=*/false,
3020                                       CXXBaseInit)) {
3021        HadError = true;
3022        continue;
3023      }
3024
3025      Info.AllToInit.push_back(CXXBaseInit);
3026    }
3027  }
3028
3029  // Fields.
3030  for (DeclContext::decl_iterator Mem = ClassDecl->decls_begin(),
3031                               MemEnd = ClassDecl->decls_end();
3032       Mem != MemEnd; ++Mem) {
3033    if (FieldDecl *F = dyn_cast<FieldDecl>(*Mem)) {
3034      // C++ [class.bit]p2:
3035      //   A declaration for a bit-field that omits the identifier declares an
3036      //   unnamed bit-field. Unnamed bit-fields are not members and cannot be
3037      //   initialized.
3038      if (F->isUnnamedBitfield())
3039        continue;
3040
3041      // If we're not generating the implicit copy/move constructor, then we'll
3042      // handle anonymous struct/union fields based on their individual
3043      // indirect fields.
3044      if (F->isAnonymousStructOrUnion() && Info.IIK == IIK_Default)
3045        continue;
3046
3047      if (CollectFieldInitializer(*this, Info, F))
3048        HadError = true;
3049      continue;
3050    }
3051
3052    // Beyond this point, we only consider default initialization.
3053    if (Info.IIK != IIK_Default)
3054      continue;
3055
3056    if (IndirectFieldDecl *F = dyn_cast<IndirectFieldDecl>(*Mem)) {
3057      if (F->getType()->isIncompleteArrayType()) {
3058        assert(ClassDecl->hasFlexibleArrayMember() &&
3059               "Incomplete array type is not valid");
3060        continue;
3061      }
3062
3063      // Initialize each field of an anonymous struct individually.
3064      if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
3065        HadError = true;
3066
3067      continue;
3068    }
3069  }
3070
3071  NumInitializers = Info.AllToInit.size();
3072  if (NumInitializers > 0) {
3073    Constructor->setNumCtorInitializers(NumInitializers);
3074    CXXCtorInitializer **baseOrMemberInitializers =
3075      new (Context) CXXCtorInitializer*[NumInitializers];
3076    memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
3077           NumInitializers * sizeof(CXXCtorInitializer*));
3078    Constructor->setCtorInitializers(baseOrMemberInitializers);
3079
3080    // Constructors implicitly reference the base and member
3081    // destructors.
3082    MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
3083                                           Constructor->getParent());
3084  }
3085
3086  return HadError;
3087}
3088
3089static void *GetKeyForTopLevelField(FieldDecl *Field) {
3090  // For anonymous unions, use the class declaration as the key.
3091  if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
3092    if (RT->getDecl()->isAnonymousStructOrUnion())
3093      return static_cast<void *>(RT->getDecl());
3094  }
3095  return static_cast<void *>(Field);
3096}
3097
3098static void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
3099  return const_cast<Type*>(Context.getCanonicalType(BaseType).getTypePtr());
3100}
3101
3102static void *GetKeyForMember(ASTContext &Context,
3103                             CXXCtorInitializer *Member) {
3104  if (!Member->isAnyMemberInitializer())
3105    return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));
3106
3107  // For fields injected into the class via declaration of an anonymous union,
3108  // use its anonymous union class declaration as the unique key.
3109  FieldDecl *Field = Member->getAnyMember();
3110
3111  // If the field is a member of an anonymous struct or union, our key
3112  // is the anonymous record decl that's a direct child of the class.
3113  RecordDecl *RD = Field->getParent();
3114  if (RD->isAnonymousStructOrUnion()) {
3115    while (true) {
3116      RecordDecl *Parent = cast<RecordDecl>(RD->getDeclContext());
3117      if (Parent->isAnonymousStructOrUnion())
3118        RD = Parent;
3119      else
3120        break;
3121    }
3122
3123    return static_cast<void *>(RD);
3124  }
3125
3126  return static_cast<void *>(Field);
3127}
3128
3129static void
3130DiagnoseBaseOrMemInitializerOrder(Sema &SemaRef,
3131                                  const CXXConstructorDecl *Constructor,
3132                                  CXXCtorInitializer **Inits,
3133                                  unsigned NumInits) {
3134  if (Constructor->getDeclContext()->isDependentContext())
3135    return;
3136
3137  // Don't check initializers order unless the warning is enabled at the
3138  // location of at least one initializer.
3139  bool ShouldCheckOrder = false;
3140  for (unsigned InitIndex = 0; InitIndex != NumInits; ++InitIndex) {
3141    CXXCtorInitializer *Init = Inits[InitIndex];
3142    if (SemaRef.Diags.getDiagnosticLevel(diag::warn_initializer_out_of_order,
3143                                         Init->getSourceLocation())
3144          != DiagnosticsEngine::Ignored) {
3145      ShouldCheckOrder = true;
3146      break;
3147    }
3148  }
3149  if (!ShouldCheckOrder)
3150    return;
3151
3152  // Build the list of bases and members in the order that they'll
3153  // actually be initialized.  The explicit initializers should be in
3154  // this same order but may be missing things.
3155  SmallVector<const void*, 32> IdealInitKeys;
3156
3157  const CXXRecordDecl *ClassDecl = Constructor->getParent();
3158
3159  // 1. Virtual bases.
3160  for (CXXRecordDecl::base_class_const_iterator VBase =
3161       ClassDecl->vbases_begin(),
3162       E = ClassDecl->vbases_end(); VBase != E; ++VBase)
3163    IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase->getType()));
3164
3165  // 2. Non-virtual bases.
3166  for (CXXRecordDecl::base_class_const_iterator Base = ClassDecl->bases_begin(),
3167       E = ClassDecl->bases_end(); Base != E; ++Base) {
3168    if (Base->isVirtual())
3169      continue;
3170    IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base->getType()));
3171  }
3172
3173  // 3. Direct fields.
3174  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
3175       E = ClassDecl->field_end(); Field != E; ++Field) {
3176    if (Field->isUnnamedBitfield())
3177      continue;
3178
3179    IdealInitKeys.push_back(GetKeyForTopLevelField(*Field));
3180  }
3181
3182  unsigned NumIdealInits = IdealInitKeys.size();
3183  unsigned IdealIndex = 0;
3184
3185  CXXCtorInitializer *PrevInit = 0;
3186  for (unsigned InitIndex = 0; InitIndex != NumInits; ++InitIndex) {
3187    CXXCtorInitializer *Init = Inits[InitIndex];
3188    void *InitKey = GetKeyForMember(SemaRef.Context, Init);
3189
3190    // Scan forward to try to find this initializer in the idealized
3191    // initializers list.
3192    for (; IdealIndex != NumIdealInits; ++IdealIndex)
3193      if (InitKey == IdealInitKeys[IdealIndex])
3194        break;
3195
3196    // If we didn't find this initializer, it must be because we
3197    // scanned past it on a previous iteration.  That can only
3198    // happen if we're out of order;  emit a warning.
3199    if (IdealIndex == NumIdealInits && PrevInit) {
3200      Sema::SemaDiagnosticBuilder D =
3201        SemaRef.Diag(PrevInit->getSourceLocation(),
3202                     diag::warn_initializer_out_of_order);
3203
3204      if (PrevInit->isAnyMemberInitializer())
3205        D << 0 << PrevInit->getAnyMember()->getDeclName();
3206      else
3207        D << 1 << PrevInit->getTypeSourceInfo()->getType();
3208
3209      if (Init->isAnyMemberInitializer())
3210        D << 0 << Init->getAnyMember()->getDeclName();
3211      else
3212        D << 1 << Init->getTypeSourceInfo()->getType();
3213
3214      // Move back to the initializer's location in the ideal list.
3215      for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
3216        if (InitKey == IdealInitKeys[IdealIndex])
3217          break;
3218
3219      assert(IdealIndex != NumIdealInits &&
3220             "initializer not found in initializer list");
3221    }
3222
3223    PrevInit = Init;
3224  }
3225}
3226
3227namespace {
3228bool CheckRedundantInit(Sema &S,
3229                        CXXCtorInitializer *Init,
3230                        CXXCtorInitializer *&PrevInit) {
3231  if (!PrevInit) {
3232    PrevInit = Init;
3233    return false;
3234  }
3235
3236  if (FieldDecl *Field = Init->getMember())
3237    S.Diag(Init->getSourceLocation(),
3238           diag::err_multiple_mem_initialization)
3239      << Field->getDeclName()
3240      << Init->getSourceRange();
3241  else {
3242    const Type *BaseClass = Init->getBaseClass();
3243    assert(BaseClass && "neither field nor base");
3244    S.Diag(Init->getSourceLocation(),
3245           diag::err_multiple_base_initialization)
3246      << QualType(BaseClass, 0)
3247      << Init->getSourceRange();
3248  }
3249  S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
3250    << 0 << PrevInit->getSourceRange();
3251
3252  return true;
3253}
3254
3255typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
3256typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;
3257
3258bool CheckRedundantUnionInit(Sema &S,
3259                             CXXCtorInitializer *Init,
3260                             RedundantUnionMap &Unions) {
3261  FieldDecl *Field = Init->getAnyMember();
3262  RecordDecl *Parent = Field->getParent();
3263  NamedDecl *Child = Field;
3264
3265  while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
3266    if (Parent->isUnion()) {
3267      UnionEntry &En = Unions[Parent];
3268      if (En.first && En.first != Child) {
3269        S.Diag(Init->getSourceLocation(),
3270               diag::err_multiple_mem_union_initialization)
3271          << Field->getDeclName()
3272          << Init->getSourceRange();
3273        S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
3274          << 0 << En.second->getSourceRange();
3275        return true;
3276      }
3277      if (!En.first) {
3278        En.first = Child;
3279        En.second = Init;
3280      }
3281      if (!Parent->isAnonymousStructOrUnion())
3282        return false;
3283    }
3284
3285    Child = Parent;
3286    Parent = cast<RecordDecl>(Parent->getDeclContext());
3287  }
3288
3289  return false;
3290}
3291}
3292
3293/// ActOnMemInitializers - Handle the member initializers for a constructor.
3294void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
3295                                SourceLocation ColonLoc,
3296                                CXXCtorInitializer **meminits,
3297                                unsigned NumMemInits,
3298                                bool AnyErrors) {
3299  if (!ConstructorDecl)
3300    return;
3301
3302  AdjustDeclIfTemplate(ConstructorDecl);
3303
3304  CXXConstructorDecl *Constructor
3305    = dyn_cast<CXXConstructorDecl>(ConstructorDecl);
3306
3307  if (!Constructor) {
3308    Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
3309    return;
3310  }
3311
3312  CXXCtorInitializer **MemInits =
3313    reinterpret_cast<CXXCtorInitializer **>(meminits);
3314
3315  // Mapping for the duplicate initializers check.
3316  // For member initializers, this is keyed with a FieldDecl*.
3317  // For base initializers, this is keyed with a Type*.
3318  llvm::DenseMap<void*, CXXCtorInitializer *> Members;
3319
3320  // Mapping for the inconsistent anonymous-union initializers check.
3321  RedundantUnionMap MemberUnions;
3322
3323  bool HadError = false;
3324  for (unsigned i = 0; i < NumMemInits; i++) {
3325    CXXCtorInitializer *Init = MemInits[i];
3326
3327    // Set the source order index.
3328    Init->setSourceOrder(i);
3329
3330    if (Init->isAnyMemberInitializer()) {
3331      FieldDecl *Field = Init->getAnyMember();
3332      if (CheckRedundantInit(*this, Init, Members[Field]) ||
3333          CheckRedundantUnionInit(*this, Init, MemberUnions))
3334        HadError = true;
3335    } else if (Init->isBaseInitializer()) {
3336      void *Key = GetKeyForBase(Context, QualType(Init->getBaseClass(), 0));
3337      if (CheckRedundantInit(*this, Init, Members[Key]))
3338        HadError = true;
3339    } else {
3340      assert(Init->isDelegatingInitializer());
3341      // This must be the only initializer
3342      if (i != 0 || NumMemInits > 1) {
3343        Diag(MemInits[0]->getSourceLocation(),
3344             diag::err_delegating_initializer_alone)
3345          << MemInits[0]->getSourceRange();
3346        HadError = true;
3347        // We will treat this as being the only initializer.
3348      }
3349      SetDelegatingInitializer(Constructor, MemInits[i]);
3350      // Return immediately as the initializer is set.
3351      return;
3352    }
3353  }
3354
3355  if (HadError)
3356    return;
3357
3358  DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits, NumMemInits);
3359
3360  SetCtorInitializers(Constructor, MemInits, NumMemInits, AnyErrors);
3361}
3362
3363void
3364Sema::MarkBaseAndMemberDestructorsReferenced(SourceLocation Location,
3365                                             CXXRecordDecl *ClassDecl) {
3366  // Ignore dependent contexts. Also ignore unions, since their members never
3367  // have destructors implicitly called.
3368  if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
3369    return;
3370
3371  // FIXME: all the access-control diagnostics are positioned on the
3372  // field/base declaration.  That's probably good; that said, the
3373  // user might reasonably want to know why the destructor is being
3374  // emitted, and we currently don't say.
3375
3376  // Non-static data members.
3377  for (CXXRecordDecl::field_iterator I = ClassDecl->field_begin(),
3378       E = ClassDecl->field_end(); I != E; ++I) {
3379    FieldDecl *Field = *I;
3380    if (Field->isInvalidDecl())
3381      continue;
3382
3383    // Don't destroy incomplete or zero-length arrays.
3384    if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
3385      continue;
3386
3387    QualType FieldType = Context.getBaseElementType(Field->getType());
3388
3389    const RecordType* RT = FieldType->getAs<RecordType>();
3390    if (!RT)
3391      continue;
3392
3393    CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
3394    if (FieldClassDecl->isInvalidDecl())
3395      continue;
3396    if (FieldClassDecl->hasIrrelevantDestructor())
3397      continue;
3398    // The destructor for an implicit anonymous union member is never invoked.
3399    if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
3400      continue;
3401
3402    CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
3403    assert(Dtor && "No dtor found for FieldClassDecl!");
3404    CheckDestructorAccess(Field->getLocation(), Dtor,
3405                          PDiag(diag::err_access_dtor_field)
3406                            << Field->getDeclName()
3407                            << FieldType);
3408
3409    MarkFunctionReferenced(Location, const_cast<CXXDestructorDecl*>(Dtor));
3410    DiagnoseUseOfDecl(Dtor, Location);
3411  }
3412
3413  llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;
3414
3415  // Bases.
3416  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
3417       E = ClassDecl->bases_end(); Base != E; ++Base) {
3418    // Bases are always records in a well-formed non-dependent class.
3419    const RecordType *RT = Base->getType()->getAs<RecordType>();
3420
3421    // Remember direct virtual bases.
3422    if (Base->isVirtual())
3423      DirectVirtualBases.insert(RT);
3424
3425    CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
3426    // If our base class is invalid, we probably can't get its dtor anyway.
3427    if (BaseClassDecl->isInvalidDecl())
3428      continue;
3429    if (BaseClassDecl->hasIrrelevantDestructor())
3430      continue;
3431
3432    CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
3433    assert(Dtor && "No dtor found for BaseClassDecl!");
3434
3435    // FIXME: caret should be on the start of the class name
3436    CheckDestructorAccess(Base->getLocStart(), Dtor,
3437                          PDiag(diag::err_access_dtor_base)
3438                            << Base->getType()
3439                            << Base->getSourceRange(),
3440                          Context.getTypeDeclType(ClassDecl));
3441
3442    MarkFunctionReferenced(Location, const_cast<CXXDestructorDecl*>(Dtor));
3443    DiagnoseUseOfDecl(Dtor, Location);
3444  }
3445
3446  // Virtual bases.
3447  for (CXXRecordDecl::base_class_iterator VBase = ClassDecl->vbases_begin(),
3448       E = ClassDecl->vbases_end(); VBase != E; ++VBase) {
3449
3450    // Bases are always records in a well-formed non-dependent class.
3451    const RecordType *RT = VBase->getType()->castAs<RecordType>();
3452
3453    // Ignore direct virtual bases.
3454    if (DirectVirtualBases.count(RT))
3455      continue;
3456
3457    CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
3458    // If our base class is invalid, we probably can't get its dtor anyway.
3459    if (BaseClassDecl->isInvalidDecl())
3460      continue;
3461    if (BaseClassDecl->hasIrrelevantDestructor())
3462      continue;
3463
3464    CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
3465    assert(Dtor && "No dtor found for BaseClassDecl!");
3466    CheckDestructorAccess(ClassDecl->getLocation(), Dtor,
3467                          PDiag(diag::err_access_dtor_vbase)
3468                            << VBase->getType(),
3469                          Context.getTypeDeclType(ClassDecl));
3470
3471    MarkFunctionReferenced(Location, const_cast<CXXDestructorDecl*>(Dtor));
3472    DiagnoseUseOfDecl(Dtor, Location);
3473  }
3474}
3475
3476void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
3477  if (!CDtorDecl)
3478    return;
3479
3480  if (CXXConstructorDecl *Constructor
3481      = dyn_cast<CXXConstructorDecl>(CDtorDecl))
3482    SetCtorInitializers(Constructor, 0, 0, /*AnyErrors=*/false);
3483}
3484
3485bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
3486                                  unsigned DiagID, AbstractDiagSelID SelID) {
3487  class NonAbstractTypeDiagnoser : public TypeDiagnoser {
3488    unsigned DiagID;
3489    AbstractDiagSelID SelID;
3490
3491  public:
3492    NonAbstractTypeDiagnoser(unsigned DiagID, AbstractDiagSelID SelID)
3493      : TypeDiagnoser(DiagID == 0), DiagID(DiagID), SelID(SelID) { }
3494
3495    virtual void diagnose(Sema &S, SourceLocation Loc, QualType T) {
3496      if (SelID == -1)
3497        S.Diag(Loc, DiagID) << T;
3498      else
3499        S.Diag(Loc, DiagID) << SelID << T;
3500    }
3501  } Diagnoser(DiagID, SelID);
3502
3503  return RequireNonAbstractType(Loc, T, Diagnoser);
3504}
3505
3506bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
3507                                  TypeDiagnoser &Diagnoser) {
3508  if (!getLangOpts().CPlusPlus)
3509    return false;
3510
3511  if (const ArrayType *AT = Context.getAsArrayType(T))
3512    return RequireNonAbstractType(Loc, AT->getElementType(), Diagnoser);
3513
3514  if (const PointerType *PT = T->getAs<PointerType>()) {
3515    // Find the innermost pointer type.
3516    while (const PointerType *T = PT->getPointeeType()->getAs<PointerType>())
3517      PT = T;
3518
3519    if (const ArrayType *AT = Context.getAsArrayType(PT->getPointeeType()))
3520      return RequireNonAbstractType(Loc, AT->getElementType(), Diagnoser);
3521  }
3522
3523  const RecordType *RT = T->getAs<RecordType>();
3524  if (!RT)
3525    return false;
3526
3527  const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
3528
3529  // We can't answer whether something is abstract until it has a
3530  // definition.  If it's currently being defined, we'll walk back
3531  // over all the declarations when we have a full definition.
3532  const CXXRecordDecl *Def = RD->getDefinition();
3533  if (!Def || Def->isBeingDefined())
3534    return false;
3535
3536  if (!RD->isAbstract())
3537    return false;
3538
3539  Diagnoser.diagnose(*this, Loc, T);
3540  DiagnoseAbstractType(RD);
3541
3542  return true;
3543}
3544
3545void Sema::DiagnoseAbstractType(const CXXRecordDecl *RD) {
3546  // Check if we've already emitted the list of pure virtual functions
3547  // for this class.
3548  if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
3549    return;
3550
3551  CXXFinalOverriderMap FinalOverriders;
3552  RD->getFinalOverriders(FinalOverriders);
3553
3554  // Keep a set of seen pure methods so we won't diagnose the same method
3555  // more than once.
3556  llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;
3557
3558  for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
3559                                   MEnd = FinalOverriders.end();
3560       M != MEnd;
3561       ++M) {
3562    for (OverridingMethods::iterator SO = M->second.begin(),
3563                                  SOEnd = M->second.end();
3564         SO != SOEnd; ++SO) {
3565      // C++ [class.abstract]p4:
3566      //   A class is abstract if it contains or inherits at least one
3567      //   pure virtual function for which the final overrider is pure
3568      //   virtual.
3569
3570      //
3571      if (SO->second.size() != 1)
3572        continue;
3573
3574      if (!SO->second.front().Method->isPure())
3575        continue;
3576
3577      if (!SeenPureMethods.insert(SO->second.front().Method))
3578        continue;
3579
3580      Diag(SO->second.front().Method->getLocation(),
3581           diag::note_pure_virtual_function)
3582        << SO->second.front().Method->getDeclName() << RD->getDeclName();
3583    }
3584  }
3585
3586  if (!PureVirtualClassDiagSet)
3587    PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
3588  PureVirtualClassDiagSet->insert(RD);
3589}
3590
3591namespace {
3592struct AbstractUsageInfo {
3593  Sema &S;
3594  CXXRecordDecl *Record;
3595  CanQualType AbstractType;
3596  bool Invalid;
3597
3598  AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
3599    : S(S), Record(Record),
3600      AbstractType(S.Context.getCanonicalType(
3601                   S.Context.getTypeDeclType(Record))),
3602      Invalid(false) {}
3603
3604  void DiagnoseAbstractType() {
3605    if (Invalid) return;
3606    S.DiagnoseAbstractType(Record);
3607    Invalid = true;
3608  }
3609
3610  void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
3611};
3612
3613struct CheckAbstractUsage {
3614  AbstractUsageInfo &Info;
3615  const NamedDecl *Ctx;
3616
3617  CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
3618    : Info(Info), Ctx(Ctx) {}
3619
3620  void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
3621    switch (TL.getTypeLocClass()) {
3622#define ABSTRACT_TYPELOC(CLASS, PARENT)
3623#define TYPELOC(CLASS, PARENT) \
3624    case TypeLoc::CLASS: Check(cast<CLASS##TypeLoc>(TL), Sel); break;
3625#include "clang/AST/TypeLocNodes.def"
3626    }
3627  }
3628
3629  void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
3630    Visit(TL.getResultLoc(), Sema::AbstractReturnType);
3631    for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
3632      if (!TL.getArg(I))
3633        continue;
3634
3635      TypeSourceInfo *TSI = TL.getArg(I)->getTypeSourceInfo();
3636      if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
3637    }
3638  }
3639
3640  void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
3641    Visit(TL.getElementLoc(), Sema::AbstractArrayType);
3642  }
3643
3644  void Check(TemplateSpecializationTypeLoc TL, Sema::AbstractDiagSelID Sel) {
3645    // Visit the type parameters from a permissive context.
3646    for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
3647      TemplateArgumentLoc TAL = TL.getArgLoc(I);
3648      if (TAL.getArgument().getKind() == TemplateArgument::Type)
3649        if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
3650          Visit(TSI->getTypeLoc(), Sema::AbstractNone);
3651      // TODO: other template argument types?
3652    }
3653  }
3654
3655  // Visit pointee types from a permissive context.
3656#define CheckPolymorphic(Type) \
3657  void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
3658    Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
3659  }
3660  CheckPolymorphic(PointerTypeLoc)
3661  CheckPolymorphic(ReferenceTypeLoc)
3662  CheckPolymorphic(MemberPointerTypeLoc)
3663  CheckPolymorphic(BlockPointerTypeLoc)
3664  CheckPolymorphic(AtomicTypeLoc)
3665
3666  /// Handle all the types we haven't given a more specific
3667  /// implementation for above.
3668  void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
3669    // Every other kind of type that we haven't called out already
3670    // that has an inner type is either (1) sugar or (2) contains that
3671    // inner type in some way as a subobject.
3672    if (TypeLoc Next = TL.getNextTypeLoc())
3673      return Visit(Next, Sel);
3674
3675    // If there's no inner type and we're in a permissive context,
3676    // don't diagnose.
3677    if (Sel == Sema::AbstractNone) return;
3678
3679    // Check whether the type matches the abstract type.
3680    QualType T = TL.getType();
3681    if (T->isArrayType()) {
3682      Sel = Sema::AbstractArrayType;
3683      T = Info.S.Context.getBaseElementType(T);
3684    }
3685    CanQualType CT = T->getCanonicalTypeUnqualified().getUnqualifiedType();
3686    if (CT != Info.AbstractType) return;
3687
3688    // It matched; do some magic.
3689    if (Sel == Sema::AbstractArrayType) {
3690      Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
3691        << T << TL.getSourceRange();
3692    } else {
3693      Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
3694        << Sel << T << TL.getSourceRange();
3695    }
3696    Info.DiagnoseAbstractType();
3697  }
3698};
3699
3700void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
3701                                  Sema::AbstractDiagSelID Sel) {
3702  CheckAbstractUsage(*this, D).Visit(TL, Sel);
3703}
3704
3705}
3706
3707/// Check for invalid uses of an abstract type in a method declaration.
3708static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
3709                                    CXXMethodDecl *MD) {
3710  // No need to do the check on definitions, which require that
3711  // the return/param types be complete.
3712  if (MD->doesThisDeclarationHaveABody())
3713    return;
3714
3715  // For safety's sake, just ignore it if we don't have type source
3716  // information.  This should never happen for non-implicit methods,
3717  // but...
3718  if (TypeSourceInfo *TSI = MD->getTypeSourceInfo())
3719    Info.CheckType(MD, TSI->getTypeLoc(), Sema::AbstractNone);
3720}
3721
3722/// Check for invalid uses of an abstract type within a class definition.
3723static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
3724                                    CXXRecordDecl *RD) {
3725  for (CXXRecordDecl::decl_iterator
3726         I = RD->decls_begin(), E = RD->decls_end(); I != E; ++I) {
3727    Decl *D = *I;
3728    if (D->isImplicit()) continue;
3729
3730    // Methods and method templates.
3731    if (isa<CXXMethodDecl>(D)) {
3732      CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(D));
3733    } else if (isa<FunctionTemplateDecl>(D)) {
3734      FunctionDecl *FD = cast<FunctionTemplateDecl>(D)->getTemplatedDecl();
3735      CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(FD));
3736
3737    // Fields and static variables.
3738    } else if (isa<FieldDecl>(D)) {
3739      FieldDecl *FD = cast<FieldDecl>(D);
3740      if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
3741        Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
3742    } else if (isa<VarDecl>(D)) {
3743      VarDecl *VD = cast<VarDecl>(D);
3744      if (TypeSourceInfo *TSI = VD->getTypeSourceInfo())
3745        Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType);
3746
3747    // Nested classes and class templates.
3748    } else if (isa<CXXRecordDecl>(D)) {
3749      CheckAbstractClassUsage(Info, cast<CXXRecordDecl>(D));
3750    } else if (isa<ClassTemplateDecl>(D)) {
3751      CheckAbstractClassUsage(Info,
3752                             cast<ClassTemplateDecl>(D)->getTemplatedDecl());
3753    }
3754  }
3755}
3756
3757/// \brief Perform semantic checks on a class definition that has been
3758/// completing, introducing implicitly-declared members, checking for
3759/// abstract types, etc.
3760void Sema::CheckCompletedCXXClass(CXXRecordDecl *Record) {
3761  if (!Record)
3762    return;
3763
3764  if (Record->isAbstract() && !Record->isInvalidDecl()) {
3765    AbstractUsageInfo Info(*this, Record);
3766    CheckAbstractClassUsage(Info, Record);
3767  }
3768
3769  // If this is not an aggregate type and has no user-declared constructor,
3770  // complain about any non-static data members of reference or const scalar
3771  // type, since they will never get initializers.
3772  if (!Record->isInvalidDecl() && !Record->isDependentType() &&
3773      !Record->isAggregate() && !Record->hasUserDeclaredConstructor() &&
3774      !Record->isLambda()) {
3775    bool Complained = false;
3776    for (RecordDecl::field_iterator F = Record->field_begin(),
3777                                 FEnd = Record->field_end();
3778         F != FEnd; ++F) {
3779      if (F->hasInClassInitializer() || F->isUnnamedBitfield())
3780        continue;
3781
3782      if (F->getType()->isReferenceType() ||
3783          (F->getType().isConstQualified() && F->getType()->isScalarType())) {
3784        if (!Complained) {
3785          Diag(Record->getLocation(), diag::warn_no_constructor_for_refconst)
3786            << Record->getTagKind() << Record;
3787          Complained = true;
3788        }
3789
3790        Diag(F->getLocation(), diag::note_refconst_member_not_initialized)
3791          << F->getType()->isReferenceType()
3792          << F->getDeclName();
3793      }
3794    }
3795  }
3796
3797  if (Record->isDynamicClass() && !Record->isDependentType())
3798    DynamicClasses.push_back(Record);
3799
3800  if (Record->getIdentifier()) {
3801    // C++ [class.mem]p13:
3802    //   If T is the name of a class, then each of the following shall have a
3803    //   name different from T:
3804    //     - every member of every anonymous union that is a member of class T.
3805    //
3806    // C++ [class.mem]p14:
3807    //   In addition, if class T has a user-declared constructor (12.1), every
3808    //   non-static data member of class T shall have a name different from T.
3809    for (DeclContext::lookup_result R = Record->lookup(Record->getDeclName());
3810         R.first != R.second; ++R.first) {
3811      NamedDecl *D = *R.first;
3812      if ((isa<FieldDecl>(D) && Record->hasUserDeclaredConstructor()) ||
3813          isa<IndirectFieldDecl>(D)) {
3814        Diag(D->getLocation(), diag::err_member_name_of_class)
3815          << D->getDeclName();
3816        break;
3817      }
3818    }
3819  }
3820
3821  // Warn if the class has virtual methods but non-virtual public destructor.
3822  if (Record->isPolymorphic() && !Record->isDependentType()) {
3823    CXXDestructorDecl *dtor = Record->getDestructor();
3824    if (!dtor || (!dtor->isVirtual() && dtor->getAccess() == AS_public))
3825      Diag(dtor ? dtor->getLocation() : Record->getLocation(),
3826           diag::warn_non_virtual_dtor) << Context.getRecordType(Record);
3827  }
3828
3829  // See if a method overloads virtual methods in a base
3830  /// class without overriding any.
3831  if (!Record->isDependentType()) {
3832    for (CXXRecordDecl::method_iterator M = Record->method_begin(),
3833                                     MEnd = Record->method_end();
3834         M != MEnd; ++M) {
3835      if (!M->isStatic())
3836        DiagnoseHiddenVirtualMethods(Record, *M);
3837    }
3838  }
3839
3840  // C++0x [dcl.constexpr]p8: A constexpr specifier for a non-static member
3841  // function that is not a constructor declares that member function to be
3842  // const. [...] The class of which that function is a member shall be
3843  // a literal type.
3844  //
3845  // If the class has virtual bases, any constexpr members will already have
3846  // been diagnosed by the checks performed on the member declaration, so
3847  // suppress this (less useful) diagnostic.
3848  if (LangOpts.CPlusPlus0x && !Record->isDependentType() &&
3849      !Record->isLiteral() && !Record->getNumVBases()) {
3850    for (CXXRecordDecl::method_iterator M = Record->method_begin(),
3851                                     MEnd = Record->method_end();
3852         M != MEnd; ++M) {
3853      if (M->isConstexpr() && M->isInstance() && !isa<CXXConstructorDecl>(*M)) {
3854        switch (Record->getTemplateSpecializationKind()) {
3855        case TSK_ImplicitInstantiation:
3856        case TSK_ExplicitInstantiationDeclaration:
3857        case TSK_ExplicitInstantiationDefinition:
3858          // If a template instantiates to a non-literal type, but its members
3859          // instantiate to constexpr functions, the template is technically
3860          // ill-formed, but we allow it for sanity.
3861          continue;
3862
3863        case TSK_Undeclared:
3864        case TSK_ExplicitSpecialization:
3865          RequireLiteralType(M->getLocation(), Context.getRecordType(Record),
3866                             diag::err_constexpr_method_non_literal);
3867          break;
3868        }
3869
3870        // Only produce one error per class.
3871        break;
3872      }
3873    }
3874  }
3875
3876  // Declare inherited constructors. We do this eagerly here because:
3877  // - The standard requires an eager diagnostic for conflicting inherited
3878  //   constructors from different classes.
3879  // - The lazy declaration of the other implicit constructors is so as to not
3880  //   waste space and performance on classes that are not meant to be
3881  //   instantiated (e.g. meta-functions). This doesn't apply to classes that
3882  //   have inherited constructors.
3883  DeclareInheritedConstructors(Record);
3884}
3885
3886void Sema::CheckExplicitlyDefaultedMethods(CXXRecordDecl *Record) {
3887  for (CXXRecordDecl::method_iterator MI = Record->method_begin(),
3888                                      ME = Record->method_end();
3889       MI != ME; ++MI)
3890    if (!MI->isInvalidDecl() && MI->isExplicitlyDefaulted())
3891      CheckExplicitlyDefaultedSpecialMember(*MI);
3892}
3893
3894/// Is the special member function which would be selected to perform the
3895/// specified operation on the specified class type a constexpr constructor?
3896static bool specialMemberIsConstexpr(Sema &S, CXXRecordDecl *ClassDecl,
3897                                     Sema::CXXSpecialMember CSM,
3898                                     bool ConstArg) {
3899  Sema::SpecialMemberOverloadResult *SMOR =
3900      S.LookupSpecialMember(ClassDecl, CSM, ConstArg,
3901                            false, false, false, false);
3902  if (!SMOR || !SMOR->getMethod())
3903    // A constructor we wouldn't select can't be "involved in initializing"
3904    // anything.
3905    return true;
3906  return SMOR->getMethod()->isConstexpr();
3907}
3908
3909/// Determine whether the specified special member function would be constexpr
3910/// if it were implicitly defined.
3911static bool defaultedSpecialMemberIsConstexpr(Sema &S, CXXRecordDecl *ClassDecl,
3912                                              Sema::CXXSpecialMember CSM,
3913                                              bool ConstArg) {
3914  if (!S.getLangOpts().CPlusPlus0x)
3915    return false;
3916
3917  // C++11 [dcl.constexpr]p4:
3918  // In the definition of a constexpr constructor [...]
3919  switch (CSM) {
3920  case Sema::CXXDefaultConstructor:
3921    // Since default constructor lookup is essentially trivial (and cannot
3922    // involve, for instance, template instantiation), we compute whether a
3923    // defaulted default constructor is constexpr directly within CXXRecordDecl.
3924    //
3925    // This is important for performance; we need to know whether the default
3926    // constructor is constexpr to determine whether the type is a literal type.
3927    return ClassDecl->defaultedDefaultConstructorIsConstexpr();
3928
3929  case Sema::CXXCopyConstructor:
3930  case Sema::CXXMoveConstructor:
3931    // For copy or move constructors, we need to perform overload resolution.
3932    break;
3933
3934  case Sema::CXXCopyAssignment:
3935  case Sema::CXXMoveAssignment:
3936  case Sema::CXXDestructor:
3937  case Sema::CXXInvalid:
3938    return false;
3939  }
3940
3941  //   -- if the class is a non-empty union, or for each non-empty anonymous
3942  //      union member of a non-union class, exactly one non-static data member
3943  //      shall be initialized; [DR1359]
3944  //
3945  // If we squint, this is guaranteed, since exactly one non-static data member
3946  // will be initialized (if the constructor isn't deleted), we just don't know
3947  // which one.
3948  if (ClassDecl->isUnion())
3949    return true;
3950
3951  //   -- the class shall not have any virtual base classes;
3952  if (ClassDecl->getNumVBases())
3953    return false;
3954
3955  //   -- every constructor involved in initializing [...] base class
3956  //      sub-objects shall be a constexpr constructor;
3957  for (CXXRecordDecl::base_class_iterator B = ClassDecl->bases_begin(),
3958                                       BEnd = ClassDecl->bases_end();
3959       B != BEnd; ++B) {
3960    const RecordType *BaseType = B->getType()->getAs<RecordType>();
3961    if (!BaseType) continue;
3962
3963    CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
3964    if (!specialMemberIsConstexpr(S, BaseClassDecl, CSM, ConstArg))
3965      return false;
3966  }
3967
3968  //   -- every constructor involved in initializing non-static data members
3969  //      [...] shall be a constexpr constructor;
3970  //   -- every non-static data member and base class sub-object shall be
3971  //      initialized
3972  for (RecordDecl::field_iterator F = ClassDecl->field_begin(),
3973                               FEnd = ClassDecl->field_end();
3974       F != FEnd; ++F) {
3975    if (F->isInvalidDecl())
3976      continue;
3977    if (const RecordType *RecordTy =
3978            S.Context.getBaseElementType(F->getType())->getAs<RecordType>()) {
3979      CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
3980      if (!specialMemberIsConstexpr(S, FieldRecDecl, CSM, ConstArg))
3981        return false;
3982    }
3983  }
3984
3985  // All OK, it's constexpr!
3986  return true;
3987}
3988
3989static Sema::ImplicitExceptionSpecification
3990computeImplicitExceptionSpec(Sema &S, SourceLocation Loc, CXXMethodDecl *MD) {
3991  switch (S.getSpecialMember(MD)) {
3992  case Sema::CXXDefaultConstructor:
3993    return S.ComputeDefaultedDefaultCtorExceptionSpec(Loc, MD);
3994  case Sema::CXXCopyConstructor:
3995    return S.ComputeDefaultedCopyCtorExceptionSpec(MD);
3996  case Sema::CXXCopyAssignment:
3997    return S.ComputeDefaultedCopyAssignmentExceptionSpec(MD);
3998  case Sema::CXXMoveConstructor:
3999    return S.ComputeDefaultedMoveCtorExceptionSpec(MD);
4000  case Sema::CXXMoveAssignment:
4001    return S.ComputeDefaultedMoveAssignmentExceptionSpec(MD);
4002  case Sema::CXXDestructor:
4003    return S.ComputeDefaultedDtorExceptionSpec(MD);
4004  case Sema::CXXInvalid:
4005    break;
4006  }
4007  llvm_unreachable("only special members have implicit exception specs");
4008}
4009
4010static void
4011updateExceptionSpec(Sema &S, FunctionDecl *FD, const FunctionProtoType *FPT,
4012                    const Sema::ImplicitExceptionSpecification &ExceptSpec) {
4013  FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
4014  ExceptSpec.getEPI(EPI);
4015  const FunctionProtoType *NewFPT = cast<FunctionProtoType>(
4016    S.Context.getFunctionType(FPT->getResultType(), FPT->arg_type_begin(),
4017                              FPT->getNumArgs(), EPI));
4018  FD->setType(QualType(NewFPT, 0));
4019}
4020
4021void Sema::EvaluateImplicitExceptionSpec(SourceLocation Loc, CXXMethodDecl *MD) {
4022  const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
4023  if (FPT->getExceptionSpecType() != EST_Unevaluated)
4024    return;
4025
4026  // Evaluate the exception specification.
4027  ImplicitExceptionSpecification ExceptSpec =
4028      computeImplicitExceptionSpec(*this, Loc, MD);
4029
4030  // Update the type of the special member to use it.
4031  updateExceptionSpec(*this, MD, FPT, ExceptSpec);
4032
4033  // A user-provided destructor can be defined outside the class. When that
4034  // happens, be sure to update the exception specification on both
4035  // declarations.
4036  const FunctionProtoType *CanonicalFPT =
4037    MD->getCanonicalDecl()->getType()->castAs<FunctionProtoType>();
4038  if (CanonicalFPT->getExceptionSpecType() == EST_Unevaluated)
4039    updateExceptionSpec(*this, MD->getCanonicalDecl(),
4040                        CanonicalFPT, ExceptSpec);
4041}
4042
4043static bool isImplicitCopyCtorArgConst(Sema &S, CXXRecordDecl *ClassDecl);
4044static bool isImplicitCopyAssignmentArgConst(Sema &S, CXXRecordDecl *ClassDecl);
4045
4046void Sema::CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD) {
4047  CXXRecordDecl *RD = MD->getParent();
4048  CXXSpecialMember CSM = getSpecialMember(MD);
4049
4050  assert(MD->isExplicitlyDefaulted() && CSM != CXXInvalid &&
4051         "not an explicitly-defaulted special member");
4052
4053  // Whether this was the first-declared instance of the constructor.
4054  // This affects whether we implicitly add an exception spec and constexpr.
4055  bool First = MD == MD->getCanonicalDecl();
4056
4057  bool HadError = false;
4058
4059  // C++11 [dcl.fct.def.default]p1:
4060  //   A function that is explicitly defaulted shall
4061  //     -- be a special member function (checked elsewhere),
4062  //     -- have the same type (except for ref-qualifiers, and except that a
4063  //        copy operation can take a non-const reference) as an implicit
4064  //        declaration, and
4065  //     -- not have default arguments.
4066  unsigned ExpectedParams = 1;
4067  if (CSM == CXXDefaultConstructor || CSM == CXXDestructor)
4068    ExpectedParams = 0;
4069  if (MD->getNumParams() != ExpectedParams) {
4070    // This also checks for default arguments: a copy or move constructor with a
4071    // default argument is classified as a default constructor, and assignment
4072    // operations and destructors can't have default arguments.
4073    Diag(MD->getLocation(), diag::err_defaulted_special_member_params)
4074      << CSM << MD->getSourceRange();
4075    HadError = true;
4076  }
4077
4078  const FunctionProtoType *Type = MD->getType()->getAs<FunctionProtoType>();
4079
4080  // Compute argument constness, constexpr, and triviality.
4081  bool CanHaveConstParam = false;
4082  bool Trivial;
4083  switch (CSM) {
4084  case CXXDefaultConstructor:
4085    Trivial = RD->hasTrivialDefaultConstructor();
4086    break;
4087  case CXXCopyConstructor:
4088    CanHaveConstParam = isImplicitCopyCtorArgConst(*this, RD);
4089    Trivial = RD->hasTrivialCopyConstructor();
4090    break;
4091  case CXXCopyAssignment:
4092    CanHaveConstParam = isImplicitCopyAssignmentArgConst(*this, RD);
4093    Trivial = RD->hasTrivialCopyAssignment();
4094    break;
4095  case CXXMoveConstructor:
4096    Trivial = RD->hasTrivialMoveConstructor();
4097    break;
4098  case CXXMoveAssignment:
4099    Trivial = RD->hasTrivialMoveAssignment();
4100    break;
4101  case CXXDestructor:
4102    Trivial = RD->hasTrivialDestructor();
4103    break;
4104  case CXXInvalid:
4105    llvm_unreachable("non-special member explicitly defaulted!");
4106  }
4107
4108  QualType ReturnType = Context.VoidTy;
4109  if (CSM == CXXCopyAssignment || CSM == CXXMoveAssignment) {
4110    // Check for return type matching.
4111    ReturnType = Type->getResultType();
4112    QualType ExpectedReturnType =
4113        Context.getLValueReferenceType(Context.getTypeDeclType(RD));
4114    if (!Context.hasSameType(ReturnType, ExpectedReturnType)) {
4115      Diag(MD->getLocation(), diag::err_defaulted_special_member_return_type)
4116        << (CSM == CXXMoveAssignment) << ExpectedReturnType;
4117      HadError = true;
4118    }
4119
4120    // A defaulted special member cannot have cv-qualifiers.
4121    if (Type->getTypeQuals()) {
4122      Diag(MD->getLocation(), diag::err_defaulted_special_member_quals)
4123        << (CSM == CXXMoveAssignment);
4124      HadError = true;
4125    }
4126  }
4127
4128  // Check for parameter type matching.
4129  QualType ArgType = ExpectedParams ? Type->getArgType(0) : QualType();
4130  bool HasConstParam = false;
4131  if (ExpectedParams && ArgType->isReferenceType()) {
4132    // Argument must be reference to possibly-const T.
4133    QualType ReferentType = ArgType->getPointeeType();
4134    HasConstParam = ReferentType.isConstQualified();
4135
4136    if (ReferentType.isVolatileQualified()) {
4137      Diag(MD->getLocation(),
4138           diag::err_defaulted_special_member_volatile_param) << CSM;
4139      HadError = true;
4140    }
4141
4142    if (HasConstParam && !CanHaveConstParam) {
4143      if (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment) {
4144        Diag(MD->getLocation(),
4145             diag::err_defaulted_special_member_copy_const_param)
4146          << (CSM == CXXCopyAssignment);
4147        // FIXME: Explain why this special member can't be const.
4148      } else {
4149        Diag(MD->getLocation(),
4150             diag::err_defaulted_special_member_move_const_param)
4151          << (CSM == CXXMoveAssignment);
4152      }
4153      HadError = true;
4154    }
4155
4156    // If a function is explicitly defaulted on its first declaration, it shall
4157    // have the same parameter type as if it had been implicitly declared.
4158    // (Presumably this is to prevent it from being trivial?)
4159    if (!HasConstParam && CanHaveConstParam && First)
4160      Diag(MD->getLocation(),
4161           diag::err_defaulted_special_member_copy_non_const_param)
4162        << (CSM == CXXCopyAssignment);
4163  } else if (ExpectedParams) {
4164    // A copy assignment operator can take its argument by value, but a
4165    // defaulted one cannot.
4166    assert(CSM == CXXCopyAssignment && "unexpected non-ref argument");
4167    Diag(MD->getLocation(), diag::err_defaulted_copy_assign_not_ref);
4168    HadError = true;
4169  }
4170
4171  // Rebuild the type with the implicit exception specification added, if we
4172  // are going to need it.
4173  const FunctionProtoType *ImplicitType = 0;
4174  if (First || Type->hasExceptionSpec()) {
4175    FunctionProtoType::ExtProtoInfo EPI = Type->getExtProtoInfo();
4176    computeImplicitExceptionSpec(*this, MD->getLocation(), MD).getEPI(EPI);
4177    ImplicitType = cast<FunctionProtoType>(
4178      Context.getFunctionType(ReturnType, &ArgType, ExpectedParams, EPI));
4179  }
4180
4181  // C++11 [dcl.fct.def.default]p2:
4182  //   An explicitly-defaulted function may be declared constexpr only if it
4183  //   would have been implicitly declared as constexpr,
4184  // Do not apply this rule to members of class templates, since core issue 1358
4185  // makes such functions always instantiate to constexpr functions. For
4186  // non-constructors, this is checked elsewhere.
4187  bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, RD, CSM,
4188                                                     HasConstParam);
4189  if (isa<CXXConstructorDecl>(MD) && MD->isConstexpr() && !Constexpr &&
4190      MD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) {
4191    Diag(MD->getLocStart(), diag::err_incorrect_defaulted_constexpr) << CSM;
4192    // FIXME: Explain why the constructor can't be constexpr.
4193    HadError = true;
4194  }
4195  //   and may have an explicit exception-specification only if it is compatible
4196  //   with the exception-specification on the implicit declaration.
4197  if (Type->hasExceptionSpec() &&
4198      CheckEquivalentExceptionSpec(
4199        PDiag(diag::err_incorrect_defaulted_exception_spec) << CSM,
4200        PDiag(), ImplicitType, SourceLocation(), Type, MD->getLocation()))
4201    HadError = true;
4202
4203  //   If a function is explicitly defaulted on its first declaration,
4204  if (First) {
4205    //  -- it is implicitly considered to be constexpr if the implicit
4206    //     definition would be,
4207    MD->setConstexpr(Constexpr);
4208
4209    //  -- it is implicitly considered to have the same exception-specification
4210    //     as if it had been implicitly declared,
4211    MD->setType(QualType(ImplicitType, 0));
4212
4213    // Such a function is also trivial if the implicitly-declared function
4214    // would have been.
4215    MD->setTrivial(Trivial);
4216  }
4217
4218  if (ShouldDeleteSpecialMember(MD, CSM)) {
4219    if (First) {
4220      MD->setDeletedAsWritten();
4221    } else {
4222      // C++11 [dcl.fct.def.default]p4:
4223      //   [For a] user-provided explicitly-defaulted function [...] if such a
4224      //   function is implicitly defined as deleted, the program is ill-formed.
4225      Diag(MD->getLocation(), diag::err_out_of_line_default_deletes) << CSM;
4226      HadError = true;
4227    }
4228  }
4229
4230  if (HadError)
4231    MD->setInvalidDecl();
4232}
4233
4234namespace {
4235struct SpecialMemberDeletionInfo {
4236  Sema &S;
4237  CXXMethodDecl *MD;
4238  Sema::CXXSpecialMember CSM;
4239  bool Diagnose;
4240
4241  // Properties of the special member, computed for convenience.
4242  bool IsConstructor, IsAssignment, IsMove, ConstArg, VolatileArg;
4243  SourceLocation Loc;
4244
4245  bool AllFieldsAreConst;
4246
4247  SpecialMemberDeletionInfo(Sema &S, CXXMethodDecl *MD,
4248                            Sema::CXXSpecialMember CSM, bool Diagnose)
4249    : S(S), MD(MD), CSM(CSM), Diagnose(Diagnose),
4250      IsConstructor(false), IsAssignment(false), IsMove(false),
4251      ConstArg(false), VolatileArg(false), Loc(MD->getLocation()),
4252      AllFieldsAreConst(true) {
4253    switch (CSM) {
4254      case Sema::CXXDefaultConstructor:
4255      case Sema::CXXCopyConstructor:
4256        IsConstructor = true;
4257        break;
4258      case Sema::CXXMoveConstructor:
4259        IsConstructor = true;
4260        IsMove = true;
4261        break;
4262      case Sema::CXXCopyAssignment:
4263        IsAssignment = true;
4264        break;
4265      case Sema::CXXMoveAssignment:
4266        IsAssignment = true;
4267        IsMove = true;
4268        break;
4269      case Sema::CXXDestructor:
4270        break;
4271      case Sema::CXXInvalid:
4272        llvm_unreachable("invalid special member kind");
4273    }
4274
4275    if (MD->getNumParams()) {
4276      ConstArg = MD->getParamDecl(0)->getType().isConstQualified();
4277      VolatileArg = MD->getParamDecl(0)->getType().isVolatileQualified();
4278    }
4279  }
4280
4281  bool inUnion() const { return MD->getParent()->isUnion(); }
4282
4283  /// Look up the corresponding special member in the given class.
4284  Sema::SpecialMemberOverloadResult *lookupIn(CXXRecordDecl *Class,
4285                                              unsigned Quals) {
4286    unsigned TQ = MD->getTypeQualifiers();
4287    // cv-qualifiers on class members don't affect default ctor / dtor calls.
4288    if (CSM == Sema::CXXDefaultConstructor || CSM == Sema::CXXDestructor)
4289      Quals = 0;
4290    return S.LookupSpecialMember(Class, CSM,
4291                                 ConstArg || (Quals & Qualifiers::Const),
4292                                 VolatileArg || (Quals & Qualifiers::Volatile),
4293                                 MD->getRefQualifier() == RQ_RValue,
4294                                 TQ & Qualifiers::Const,
4295                                 TQ & Qualifiers::Volatile);
4296  }
4297
4298  typedef llvm::PointerUnion<CXXBaseSpecifier*, FieldDecl*> Subobject;
4299
4300  bool shouldDeleteForBase(CXXBaseSpecifier *Base);
4301  bool shouldDeleteForField(FieldDecl *FD);
4302  bool shouldDeleteForAllConstMembers();
4303
4304  bool shouldDeleteForClassSubobject(CXXRecordDecl *Class, Subobject Subobj,
4305                                     unsigned Quals);
4306  bool shouldDeleteForSubobjectCall(Subobject Subobj,
4307                                    Sema::SpecialMemberOverloadResult *SMOR,
4308                                    bool IsDtorCallInCtor);
4309
4310  bool isAccessible(Subobject Subobj, CXXMethodDecl *D);
4311};
4312}
4313
4314/// Is the given special member inaccessible when used on the given
4315/// sub-object.
4316bool SpecialMemberDeletionInfo::isAccessible(Subobject Subobj,
4317                                             CXXMethodDecl *target) {
4318  /// If we're operating on a base class, the object type is the
4319  /// type of this special member.
4320  QualType objectTy;
4321  AccessSpecifier access = target->getAccess();;
4322  if (CXXBaseSpecifier *base = Subobj.dyn_cast<CXXBaseSpecifier*>()) {
4323    objectTy = S.Context.getTypeDeclType(MD->getParent());
4324    access = CXXRecordDecl::MergeAccess(base->getAccessSpecifier(), access);
4325
4326  // If we're operating on a field, the object type is the type of the field.
4327  } else {
4328    objectTy = S.Context.getTypeDeclType(target->getParent());
4329  }
4330
4331  return S.isSpecialMemberAccessibleForDeletion(target, access, objectTy);
4332}
4333
4334/// Check whether we should delete a special member due to the implicit
4335/// definition containing a call to a special member of a subobject.
4336bool SpecialMemberDeletionInfo::shouldDeleteForSubobjectCall(
4337    Subobject Subobj, Sema::SpecialMemberOverloadResult *SMOR,
4338    bool IsDtorCallInCtor) {
4339  CXXMethodDecl *Decl = SMOR->getMethod();
4340  FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
4341
4342  int DiagKind = -1;
4343
4344  if (SMOR->getKind() == Sema::SpecialMemberOverloadResult::NoMemberOrDeleted)
4345    DiagKind = !Decl ? 0 : 1;
4346  else if (SMOR->getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
4347    DiagKind = 2;
4348  else if (!isAccessible(Subobj, Decl))
4349    DiagKind = 3;
4350  else if (!IsDtorCallInCtor && Field && Field->getParent()->isUnion() &&
4351           !Decl->isTrivial()) {
4352    // A member of a union must have a trivial corresponding special member.
4353    // As a weird special case, a destructor call from a union's constructor
4354    // must be accessible and non-deleted, but need not be trivial. Such a
4355    // destructor is never actually called, but is semantically checked as
4356    // if it were.
4357    DiagKind = 4;
4358  }
4359
4360  if (DiagKind == -1)
4361    return false;
4362
4363  if (Diagnose) {
4364    if (Field) {
4365      S.Diag(Field->getLocation(),
4366             diag::note_deleted_special_member_class_subobject)
4367        << CSM << MD->getParent() << /*IsField*/true
4368        << Field << DiagKind << IsDtorCallInCtor;
4369    } else {
4370      CXXBaseSpecifier *Base = Subobj.get<CXXBaseSpecifier*>();
4371      S.Diag(Base->getLocStart(),
4372             diag::note_deleted_special_member_class_subobject)
4373        << CSM << MD->getParent() << /*IsField*/false
4374        << Base->getType() << DiagKind << IsDtorCallInCtor;
4375    }
4376
4377    if (DiagKind == 1)
4378      S.NoteDeletedFunction(Decl);
4379    // FIXME: Explain inaccessibility if DiagKind == 3.
4380  }
4381
4382  return true;
4383}
4384
4385/// Check whether we should delete a special member function due to having a
4386/// direct or virtual base class or non-static data member of class type M.
4387bool SpecialMemberDeletionInfo::shouldDeleteForClassSubobject(
4388    CXXRecordDecl *Class, Subobject Subobj, unsigned Quals) {
4389  FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
4390
4391  // C++11 [class.ctor]p5:
4392  // -- any direct or virtual base class, or non-static data member with no
4393  //    brace-or-equal-initializer, has class type M (or array thereof) and
4394  //    either M has no default constructor or overload resolution as applied
4395  //    to M's default constructor results in an ambiguity or in a function
4396  //    that is deleted or inaccessible
4397  // C++11 [class.copy]p11, C++11 [class.copy]p23:
4398  // -- a direct or virtual base class B that cannot be copied/moved because
4399  //    overload resolution, as applied to B's corresponding special member,
4400  //    results in an ambiguity or a function that is deleted or inaccessible
4401  //    from the defaulted special member
4402  // C++11 [class.dtor]p5:
4403  // -- any direct or virtual base class [...] has a type with a destructor
4404  //    that is deleted or inaccessible
4405  if (!(CSM == Sema::CXXDefaultConstructor &&
4406        Field && Field->hasInClassInitializer()) &&
4407      shouldDeleteForSubobjectCall(Subobj, lookupIn(Class, Quals), false))
4408    return true;
4409
4410  // C++11 [class.ctor]p5, C++11 [class.copy]p11:
4411  // -- any direct or virtual base class or non-static data member has a
4412  //    type with a destructor that is deleted or inaccessible
4413  if (IsConstructor) {
4414    Sema::SpecialMemberOverloadResult *SMOR =
4415        S.LookupSpecialMember(Class, Sema::CXXDestructor,
4416                              false, false, false, false, false);
4417    if (shouldDeleteForSubobjectCall(Subobj, SMOR, true))
4418      return true;
4419  }
4420
4421  return false;
4422}
4423
4424/// Check whether we should delete a special member function due to the class
4425/// having a particular direct or virtual base class.
4426bool SpecialMemberDeletionInfo::shouldDeleteForBase(CXXBaseSpecifier *Base) {
4427  CXXRecordDecl *BaseClass = Base->getType()->getAsCXXRecordDecl();
4428  return shouldDeleteForClassSubobject(BaseClass, Base, 0);
4429}
4430
4431/// Check whether we should delete a special member function due to the class
4432/// having a particular non-static data member.
4433bool SpecialMemberDeletionInfo::shouldDeleteForField(FieldDecl *FD) {
4434  QualType FieldType = S.Context.getBaseElementType(FD->getType());
4435  CXXRecordDecl *FieldRecord = FieldType->getAsCXXRecordDecl();
4436
4437  if (CSM == Sema::CXXDefaultConstructor) {
4438    // For a default constructor, all references must be initialized in-class
4439    // and, if a union, it must have a non-const member.
4440    if (FieldType->isReferenceType() && !FD->hasInClassInitializer()) {
4441      if (Diagnose)
4442        S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
4443          << MD->getParent() << FD << FieldType << /*Reference*/0;
4444      return true;
4445    }
4446    // C++11 [class.ctor]p5: any non-variant non-static data member of
4447    // const-qualified type (or array thereof) with no
4448    // brace-or-equal-initializer does not have a user-provided default
4449    // constructor.
4450    if (!inUnion() && FieldType.isConstQualified() &&
4451        !FD->hasInClassInitializer() &&
4452        (!FieldRecord || !FieldRecord->hasUserProvidedDefaultConstructor())) {
4453      if (Diagnose)
4454        S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
4455          << MD->getParent() << FD << FD->getType() << /*Const*/1;
4456      return true;
4457    }
4458
4459    if (inUnion() && !FieldType.isConstQualified())
4460      AllFieldsAreConst = false;
4461  } else if (CSM == Sema::CXXCopyConstructor) {
4462    // For a copy constructor, data members must not be of rvalue reference
4463    // type.
4464    if (FieldType->isRValueReferenceType()) {
4465      if (Diagnose)
4466        S.Diag(FD->getLocation(), diag::note_deleted_copy_ctor_rvalue_reference)
4467          << MD->getParent() << FD << FieldType;
4468      return true;
4469    }
4470  } else if (IsAssignment) {
4471    // For an assignment operator, data members must not be of reference type.
4472    if (FieldType->isReferenceType()) {
4473      if (Diagnose)
4474        S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
4475          << IsMove << MD->getParent() << FD << FieldType << /*Reference*/0;
4476      return true;
4477    }
4478    if (!FieldRecord && FieldType.isConstQualified()) {
4479      // C++11 [class.copy]p23:
4480      // -- a non-static data member of const non-class type (or array thereof)
4481      if (Diagnose)
4482        S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
4483          << IsMove << MD->getParent() << FD << FD->getType() << /*Const*/1;
4484      return true;
4485    }
4486  }
4487
4488  if (FieldRecord) {
4489    // Some additional restrictions exist on the variant members.
4490    if (!inUnion() && FieldRecord->isUnion() &&
4491        FieldRecord->isAnonymousStructOrUnion()) {
4492      bool AllVariantFieldsAreConst = true;
4493
4494      // FIXME: Handle anonymous unions declared within anonymous unions.
4495      for (CXXRecordDecl::field_iterator UI = FieldRecord->field_begin(),
4496                                         UE = FieldRecord->field_end();
4497           UI != UE; ++UI) {
4498        QualType UnionFieldType = S.Context.getBaseElementType(UI->getType());
4499
4500        if (!UnionFieldType.isConstQualified())
4501          AllVariantFieldsAreConst = false;
4502
4503        CXXRecordDecl *UnionFieldRecord = UnionFieldType->getAsCXXRecordDecl();
4504        if (UnionFieldRecord &&
4505            shouldDeleteForClassSubobject(UnionFieldRecord, *UI,
4506                                          UnionFieldType.getCVRQualifiers()))
4507          return true;
4508      }
4509
4510      // At least one member in each anonymous union must be non-const
4511      if (CSM == Sema::CXXDefaultConstructor && AllVariantFieldsAreConst &&
4512          FieldRecord->field_begin() != FieldRecord->field_end()) {
4513        if (Diagnose)
4514          S.Diag(FieldRecord->getLocation(),
4515                 diag::note_deleted_default_ctor_all_const)
4516            << MD->getParent() << /*anonymous union*/1;
4517        return true;
4518      }
4519
4520      // Don't check the implicit member of the anonymous union type.
4521      // This is technically non-conformant, but sanity demands it.
4522      return false;
4523    }
4524
4525    if (shouldDeleteForClassSubobject(FieldRecord, FD,
4526                                      FieldType.getCVRQualifiers()))
4527      return true;
4528  }
4529
4530  return false;
4531}
4532
4533/// C++11 [class.ctor] p5:
4534///   A defaulted default constructor for a class X is defined as deleted if
4535/// X is a union and all of its variant members are of const-qualified type.
4536bool SpecialMemberDeletionInfo::shouldDeleteForAllConstMembers() {
4537  // This is a silly definition, because it gives an empty union a deleted
4538  // default constructor. Don't do that.
4539  if (CSM == Sema::CXXDefaultConstructor && inUnion() && AllFieldsAreConst &&
4540      (MD->getParent()->field_begin() != MD->getParent()->field_end())) {
4541    if (Diagnose)
4542      S.Diag(MD->getParent()->getLocation(),
4543             diag::note_deleted_default_ctor_all_const)
4544        << MD->getParent() << /*not anonymous union*/0;
4545    return true;
4546  }
4547  return false;
4548}
4549
4550/// Determine whether a defaulted special member function should be defined as
4551/// deleted, as specified in C++11 [class.ctor]p5, C++11 [class.copy]p11,
4552/// C++11 [class.copy]p23, and C++11 [class.dtor]p5.
4553bool Sema::ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM,
4554                                     bool Diagnose) {
4555  if (MD->isInvalidDecl())
4556    return false;
4557  CXXRecordDecl *RD = MD->getParent();
4558  assert(!RD->isDependentType() && "do deletion after instantiation");
4559  if (!LangOpts.CPlusPlus0x || RD->isInvalidDecl())
4560    return false;
4561
4562  // C++11 [expr.lambda.prim]p19:
4563  //   The closure type associated with a lambda-expression has a
4564  //   deleted (8.4.3) default constructor and a deleted copy
4565  //   assignment operator.
4566  if (RD->isLambda() &&
4567      (CSM == CXXDefaultConstructor || CSM == CXXCopyAssignment)) {
4568    if (Diagnose)
4569      Diag(RD->getLocation(), diag::note_lambda_decl);
4570    return true;
4571  }
4572
4573  // For an anonymous struct or union, the copy and assignment special members
4574  // will never be used, so skip the check. For an anonymous union declared at
4575  // namespace scope, the constructor and destructor are used.
4576  if (CSM != CXXDefaultConstructor && CSM != CXXDestructor &&
4577      RD->isAnonymousStructOrUnion())
4578    return false;
4579
4580  // C++11 [class.copy]p7, p18:
4581  //   If the class definition declares a move constructor or move assignment
4582  //   operator, an implicitly declared copy constructor or copy assignment
4583  //   operator is defined as deleted.
4584  if (MD->isImplicit() &&
4585      (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment)) {
4586    CXXMethodDecl *UserDeclaredMove = 0;
4587
4588    // In Microsoft mode, a user-declared move only causes the deletion of the
4589    // corresponding copy operation, not both copy operations.
4590    if (RD->hasUserDeclaredMoveConstructor() &&
4591        (!getLangOpts().MicrosoftMode || CSM == CXXCopyConstructor)) {
4592      if (!Diagnose) return true;
4593      UserDeclaredMove = RD->getMoveConstructor();
4594      assert(UserDeclaredMove);
4595    } else if (RD->hasUserDeclaredMoveAssignment() &&
4596               (!getLangOpts().MicrosoftMode || CSM == CXXCopyAssignment)) {
4597      if (!Diagnose) return true;
4598      UserDeclaredMove = RD->getMoveAssignmentOperator();
4599      assert(UserDeclaredMove);
4600    }
4601
4602    if (UserDeclaredMove) {
4603      Diag(UserDeclaredMove->getLocation(),
4604           diag::note_deleted_copy_user_declared_move)
4605        << (CSM == CXXCopyAssignment) << RD
4606        << UserDeclaredMove->isMoveAssignmentOperator();
4607      return true;
4608    }
4609  }
4610
4611  // Do access control from the special member function
4612  ContextRAII MethodContext(*this, MD);
4613
4614  // C++11 [class.dtor]p5:
4615  // -- for a virtual destructor, lookup of the non-array deallocation function
4616  //    results in an ambiguity or in a function that is deleted or inaccessible
4617  if (CSM == CXXDestructor && MD->isVirtual()) {
4618    FunctionDecl *OperatorDelete = 0;
4619    DeclarationName Name =
4620      Context.DeclarationNames.getCXXOperatorName(OO_Delete);
4621    if (FindDeallocationFunction(MD->getLocation(), MD->getParent(), Name,
4622                                 OperatorDelete, false)) {
4623      if (Diagnose)
4624        Diag(RD->getLocation(), diag::note_deleted_dtor_no_operator_delete);
4625      return true;
4626    }
4627  }
4628
4629  SpecialMemberDeletionInfo SMI(*this, MD, CSM, Diagnose);
4630
4631  for (CXXRecordDecl::base_class_iterator BI = RD->bases_begin(),
4632                                          BE = RD->bases_end(); BI != BE; ++BI)
4633    if (!BI->isVirtual() &&
4634        SMI.shouldDeleteForBase(BI))
4635      return true;
4636
4637  for (CXXRecordDecl::base_class_iterator BI = RD->vbases_begin(),
4638                                          BE = RD->vbases_end(); BI != BE; ++BI)
4639    if (SMI.shouldDeleteForBase(BI))
4640      return true;
4641
4642  for (CXXRecordDecl::field_iterator FI = RD->field_begin(),
4643                                     FE = RD->field_end(); FI != FE; ++FI)
4644    if (!FI->isInvalidDecl() && !FI->isUnnamedBitfield() &&
4645        SMI.shouldDeleteForField(*FI))
4646      return true;
4647
4648  if (SMI.shouldDeleteForAllConstMembers())
4649    return true;
4650
4651  return false;
4652}
4653
4654/// \brief Data used with FindHiddenVirtualMethod
4655namespace {
4656  struct FindHiddenVirtualMethodData {
4657    Sema *S;
4658    CXXMethodDecl *Method;
4659    llvm::SmallPtrSet<const CXXMethodDecl *, 8> OverridenAndUsingBaseMethods;
4660    SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
4661  };
4662}
4663
4664/// \brief Member lookup function that determines whether a given C++
4665/// method overloads virtual methods in a base class without overriding any,
4666/// to be used with CXXRecordDecl::lookupInBases().
4667static bool FindHiddenVirtualMethod(const CXXBaseSpecifier *Specifier,
4668                                    CXXBasePath &Path,
4669                                    void *UserData) {
4670  RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl();
4671
4672  FindHiddenVirtualMethodData &Data
4673    = *static_cast<FindHiddenVirtualMethodData*>(UserData);
4674
4675  DeclarationName Name = Data.Method->getDeclName();
4676  assert(Name.getNameKind() == DeclarationName::Identifier);
4677
4678  bool foundSameNameMethod = false;
4679  SmallVector<CXXMethodDecl *, 8> overloadedMethods;
4680  for (Path.Decls = BaseRecord->lookup(Name);
4681       Path.Decls.first != Path.Decls.second;
4682       ++Path.Decls.first) {
4683    NamedDecl *D = *Path.Decls.first;
4684    if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
4685      MD = MD->getCanonicalDecl();
4686      foundSameNameMethod = true;
4687      // Interested only in hidden virtual methods.
4688      if (!MD->isVirtual())
4689        continue;
4690      // If the method we are checking overrides a method from its base
4691      // don't warn about the other overloaded methods.
4692      if (!Data.S->IsOverload(Data.Method, MD, false))
4693        return true;
4694      // Collect the overload only if its hidden.
4695      if (!Data.OverridenAndUsingBaseMethods.count(MD))
4696        overloadedMethods.push_back(MD);
4697    }
4698  }
4699
4700  if (foundSameNameMethod)
4701    Data.OverloadedMethods.append(overloadedMethods.begin(),
4702                                   overloadedMethods.end());
4703  return foundSameNameMethod;
4704}
4705
4706/// \brief See if a method overloads virtual methods in a base class without
4707/// overriding any.
4708void Sema::DiagnoseHiddenVirtualMethods(CXXRecordDecl *DC, CXXMethodDecl *MD) {
4709  if (Diags.getDiagnosticLevel(diag::warn_overloaded_virtual,
4710                               MD->getLocation()) == DiagnosticsEngine::Ignored)
4711    return;
4712  if (!MD->getDeclName().isIdentifier())
4713    return;
4714
4715  CXXBasePaths Paths(/*FindAmbiguities=*/true, // true to look in all bases.
4716                     /*bool RecordPaths=*/false,
4717                     /*bool DetectVirtual=*/false);
4718  FindHiddenVirtualMethodData Data;
4719  Data.Method = MD;
4720  Data.S = this;
4721
4722  // Keep the base methods that were overriden or introduced in the subclass
4723  // by 'using' in a set. A base method not in this set is hidden.
4724  for (DeclContext::lookup_result res = DC->lookup(MD->getDeclName());
4725       res.first != res.second; ++res.first) {
4726    if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(*res.first))
4727      for (CXXMethodDecl::method_iterator I = MD->begin_overridden_methods(),
4728                                          E = MD->end_overridden_methods();
4729           I != E; ++I)
4730        Data.OverridenAndUsingBaseMethods.insert((*I)->getCanonicalDecl());
4731    if (UsingShadowDecl *shad = dyn_cast<UsingShadowDecl>(*res.first))
4732      if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(shad->getTargetDecl()))
4733        Data.OverridenAndUsingBaseMethods.insert(MD->getCanonicalDecl());
4734  }
4735
4736  if (DC->lookupInBases(&FindHiddenVirtualMethod, &Data, Paths) &&
4737      !Data.OverloadedMethods.empty()) {
4738    Diag(MD->getLocation(), diag::warn_overloaded_virtual)
4739      << MD << (Data.OverloadedMethods.size() > 1);
4740
4741    for (unsigned i = 0, e = Data.OverloadedMethods.size(); i != e; ++i) {
4742      CXXMethodDecl *overloadedMD = Data.OverloadedMethods[i];
4743      Diag(overloadedMD->getLocation(),
4744           diag::note_hidden_overloaded_virtual_declared_here) << overloadedMD;
4745    }
4746  }
4747}
4748
4749void Sema::ActOnFinishCXXMemberSpecification(Scope* S, SourceLocation RLoc,
4750                                             Decl *TagDecl,
4751                                             SourceLocation LBrac,
4752                                             SourceLocation RBrac,
4753                                             AttributeList *AttrList) {
4754  if (!TagDecl)
4755    return;
4756
4757  AdjustDeclIfTemplate(TagDecl);
4758
4759  for (const AttributeList* l = AttrList; l; l = l->getNext()) {
4760    if (l->getKind() != AttributeList::AT_Visibility)
4761      continue;
4762    l->setInvalid();
4763    Diag(l->getLoc(), diag::warn_attribute_after_definition_ignored) <<
4764      l->getName();
4765  }
4766
4767  ActOnFields(S, RLoc, TagDecl, llvm::makeArrayRef(
4768              // strict aliasing violation!
4769              reinterpret_cast<Decl**>(FieldCollector->getCurFields()),
4770              FieldCollector->getCurNumFields()), LBrac, RBrac, AttrList);
4771
4772  CheckCompletedCXXClass(
4773                        dyn_cast_or_null<CXXRecordDecl>(TagDecl));
4774}
4775
4776/// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared
4777/// special functions, such as the default constructor, copy
4778/// constructor, or destructor, to the given C++ class (C++
4779/// [special]p1).  This routine can only be executed just before the
4780/// definition of the class is complete.
4781void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) {
4782  if (!ClassDecl->hasUserDeclaredConstructor())
4783    ++ASTContext::NumImplicitDefaultConstructors;
4784
4785  if (!ClassDecl->hasUserDeclaredCopyConstructor())
4786    ++ASTContext::NumImplicitCopyConstructors;
4787
4788  if (getLangOpts().CPlusPlus0x && ClassDecl->needsImplicitMoveConstructor())
4789    ++ASTContext::NumImplicitMoveConstructors;
4790
4791  if (!ClassDecl->hasUserDeclaredCopyAssignment()) {
4792    ++ASTContext::NumImplicitCopyAssignmentOperators;
4793
4794    // If we have a dynamic class, then the copy assignment operator may be
4795    // virtual, so we have to declare it immediately. This ensures that, e.g.,
4796    // it shows up in the right place in the vtable and that we diagnose
4797    // problems with the implicit exception specification.
4798    if (ClassDecl->isDynamicClass())
4799      DeclareImplicitCopyAssignment(ClassDecl);
4800  }
4801
4802  if (getLangOpts().CPlusPlus0x && ClassDecl->needsImplicitMoveAssignment()) {
4803    ++ASTContext::NumImplicitMoveAssignmentOperators;
4804
4805    // Likewise for the move assignment operator.
4806    if (ClassDecl->isDynamicClass())
4807      DeclareImplicitMoveAssignment(ClassDecl);
4808  }
4809
4810  if (!ClassDecl->hasUserDeclaredDestructor()) {
4811    ++ASTContext::NumImplicitDestructors;
4812
4813    // If we have a dynamic class, then the destructor may be virtual, so we
4814    // have to declare the destructor immediately. This ensures that, e.g., it
4815    // shows up in the right place in the vtable and that we diagnose problems
4816    // with the implicit exception specification.
4817    if (ClassDecl->isDynamicClass())
4818      DeclareImplicitDestructor(ClassDecl);
4819  }
4820}
4821
4822void Sema::ActOnReenterDeclaratorTemplateScope(Scope *S, DeclaratorDecl *D) {
4823  if (!D)
4824    return;
4825
4826  int NumParamList = D->getNumTemplateParameterLists();
4827  for (int i = 0; i < NumParamList; i++) {
4828    TemplateParameterList* Params = D->getTemplateParameterList(i);
4829    for (TemplateParameterList::iterator Param = Params->begin(),
4830                                      ParamEnd = Params->end();
4831          Param != ParamEnd; ++Param) {
4832      NamedDecl *Named = cast<NamedDecl>(*Param);
4833      if (Named->getDeclName()) {
4834        S->AddDecl(Named);
4835        IdResolver.AddDecl(Named);
4836      }
4837    }
4838  }
4839}
4840
4841void Sema::ActOnReenterTemplateScope(Scope *S, Decl *D) {
4842  if (!D)
4843    return;
4844
4845  TemplateParameterList *Params = 0;
4846  if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D))
4847    Params = Template->getTemplateParameters();
4848  else if (ClassTemplatePartialSpecializationDecl *PartialSpec
4849           = dyn_cast<ClassTemplatePartialSpecializationDecl>(D))
4850    Params = PartialSpec->getTemplateParameters();
4851  else
4852    return;
4853
4854  for (TemplateParameterList::iterator Param = Params->begin(),
4855                                    ParamEnd = Params->end();
4856       Param != ParamEnd; ++Param) {
4857    NamedDecl *Named = cast<NamedDecl>(*Param);
4858    if (Named->getDeclName()) {
4859      S->AddDecl(Named);
4860      IdResolver.AddDecl(Named);
4861    }
4862  }
4863}
4864
4865void Sema::ActOnStartDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
4866  if (!RecordD) return;
4867  AdjustDeclIfTemplate(RecordD);
4868  CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordD);
4869  PushDeclContext(S, Record);
4870}
4871
4872void Sema::ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
4873  if (!RecordD) return;
4874  PopDeclContext();
4875}
4876
4877/// ActOnStartDelayedCXXMethodDeclaration - We have completed
4878/// parsing a top-level (non-nested) C++ class, and we are now
4879/// parsing those parts of the given Method declaration that could
4880/// not be parsed earlier (C++ [class.mem]p2), such as default
4881/// arguments. This action should enter the scope of the given
4882/// Method declaration as if we had just parsed the qualified method
4883/// name. However, it should not bring the parameters into scope;
4884/// that will be performed by ActOnDelayedCXXMethodParameter.
4885void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
4886}
4887
4888/// ActOnDelayedCXXMethodParameter - We've already started a delayed
4889/// C++ method declaration. We're (re-)introducing the given
4890/// function parameter into scope for use in parsing later parts of
4891/// the method declaration. For example, we could see an
4892/// ActOnParamDefaultArgument event for this parameter.
4893void Sema::ActOnDelayedCXXMethodParameter(Scope *S, Decl *ParamD) {
4894  if (!ParamD)
4895    return;
4896
4897  ParmVarDecl *Param = cast<ParmVarDecl>(ParamD);
4898
4899  // If this parameter has an unparsed default argument, clear it out
4900  // to make way for the parsed default argument.
4901  if (Param->hasUnparsedDefaultArg())
4902    Param->setDefaultArg(0);
4903
4904  S->AddDecl(Param);
4905  if (Param->getDeclName())
4906    IdResolver.AddDecl(Param);
4907}
4908
4909/// ActOnFinishDelayedCXXMethodDeclaration - We have finished
4910/// processing the delayed method declaration for Method. The method
4911/// declaration is now considered finished. There may be a separate
4912/// ActOnStartOfFunctionDef action later (not necessarily
4913/// immediately!) for this method, if it was also defined inside the
4914/// class body.
4915void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
4916  if (!MethodD)
4917    return;
4918
4919  AdjustDeclIfTemplate(MethodD);
4920
4921  FunctionDecl *Method = cast<FunctionDecl>(MethodD);
4922
4923  // Now that we have our default arguments, check the constructor
4924  // again. It could produce additional diagnostics or affect whether
4925  // the class has implicitly-declared destructors, among other
4926  // things.
4927  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method))
4928    CheckConstructor(Constructor);
4929
4930  // Check the default arguments, which we may have added.
4931  if (!Method->isInvalidDecl())
4932    CheckCXXDefaultArguments(Method);
4933}
4934
4935/// CheckConstructorDeclarator - Called by ActOnDeclarator to check
4936/// the well-formedness of the constructor declarator @p D with type @p
4937/// R. If there are any errors in the declarator, this routine will
4938/// emit diagnostics and set the invalid bit to true.  In any case, the type
4939/// will be updated to reflect a well-formed type for the constructor and
4940/// returned.
4941QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R,
4942                                          StorageClass &SC) {
4943  bool isVirtual = D.getDeclSpec().isVirtualSpecified();
4944
4945  // C++ [class.ctor]p3:
4946  //   A constructor shall not be virtual (10.3) or static (9.4). A
4947  //   constructor can be invoked for a const, volatile or const
4948  //   volatile object. A constructor shall not be declared const,
4949  //   volatile, or const volatile (9.3.2).
4950  if (isVirtual) {
4951    if (!D.isInvalidType())
4952      Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
4953        << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc())
4954        << SourceRange(D.getIdentifierLoc());
4955    D.setInvalidType();
4956  }
4957  if (SC == SC_Static) {
4958    if (!D.isInvalidType())
4959      Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
4960        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
4961        << SourceRange(D.getIdentifierLoc());
4962    D.setInvalidType();
4963    SC = SC_None;
4964  }
4965
4966  DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
4967  if (FTI.TypeQuals != 0) {
4968    if (FTI.TypeQuals & Qualifiers::Const)
4969      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
4970        << "const" << SourceRange(D.getIdentifierLoc());
4971    if (FTI.TypeQuals & Qualifiers::Volatile)
4972      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
4973        << "volatile" << SourceRange(D.getIdentifierLoc());
4974    if (FTI.TypeQuals & Qualifiers::Restrict)
4975      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
4976        << "restrict" << SourceRange(D.getIdentifierLoc());
4977    D.setInvalidType();
4978  }
4979
4980  // C++0x [class.ctor]p4:
4981  //   A constructor shall not be declared with a ref-qualifier.
4982  if (FTI.hasRefQualifier()) {
4983    Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_constructor)
4984      << FTI.RefQualifierIsLValueRef
4985      << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
4986    D.setInvalidType();
4987  }
4988
4989  // Rebuild the function type "R" without any type qualifiers (in
4990  // case any of the errors above fired) and with "void" as the
4991  // return type, since constructors don't have return types.
4992  const FunctionProtoType *Proto = R->getAs<FunctionProtoType>();
4993  if (Proto->getResultType() == Context.VoidTy && !D.isInvalidType())
4994    return R;
4995
4996  FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
4997  EPI.TypeQuals = 0;
4998  EPI.RefQualifier = RQ_None;
4999
5000  return Context.getFunctionType(Context.VoidTy, Proto->arg_type_begin(),
5001                                 Proto->getNumArgs(), EPI);
5002}
5003
5004/// CheckConstructor - Checks a fully-formed constructor for
5005/// well-formedness, issuing any diagnostics required. Returns true if
5006/// the constructor declarator is invalid.
5007void Sema::CheckConstructor(CXXConstructorDecl *Constructor) {
5008  CXXRecordDecl *ClassDecl
5009    = dyn_cast<CXXRecordDecl>(Constructor->getDeclContext());
5010  if (!ClassDecl)
5011    return Constructor->setInvalidDecl();
5012
5013  // C++ [class.copy]p3:
5014  //   A declaration of a constructor for a class X is ill-formed if
5015  //   its first parameter is of type (optionally cv-qualified) X and
5016  //   either there are no other parameters or else all other
5017  //   parameters have default arguments.
5018  if (!Constructor->isInvalidDecl() &&
5019      ((Constructor->getNumParams() == 1) ||
5020       (Constructor->getNumParams() > 1 &&
5021        Constructor->getParamDecl(1)->hasDefaultArg())) &&
5022      Constructor->getTemplateSpecializationKind()
5023                                              != TSK_ImplicitInstantiation) {
5024    QualType ParamType = Constructor->getParamDecl(0)->getType();
5025    QualType ClassTy = Context.getTagDeclType(ClassDecl);
5026    if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) {
5027      SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation();
5028      const char *ConstRef
5029        = Constructor->getParamDecl(0)->getIdentifier() ? "const &"
5030                                                        : " const &";
5031      Diag(ParamLoc, diag::err_constructor_byvalue_arg)
5032        << FixItHint::CreateInsertion(ParamLoc, ConstRef);
5033
5034      // FIXME: Rather that making the constructor invalid, we should endeavor
5035      // to fix the type.
5036      Constructor->setInvalidDecl();
5037    }
5038  }
5039}
5040
5041/// CheckDestructor - Checks a fully-formed destructor definition for
5042/// well-formedness, issuing any diagnostics required.  Returns true
5043/// on error.
5044bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) {
5045  CXXRecordDecl *RD = Destructor->getParent();
5046
5047  if (Destructor->isVirtual()) {
5048    SourceLocation Loc;
5049
5050    if (!Destructor->isImplicit())
5051      Loc = Destructor->getLocation();
5052    else
5053      Loc = RD->getLocation();
5054
5055    // If we have a virtual destructor, look up the deallocation function
5056    FunctionDecl *OperatorDelete = 0;
5057    DeclarationName Name =
5058    Context.DeclarationNames.getCXXOperatorName(OO_Delete);
5059    if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete))
5060      return true;
5061
5062    MarkFunctionReferenced(Loc, OperatorDelete);
5063
5064    Destructor->setOperatorDelete(OperatorDelete);
5065  }
5066
5067  return false;
5068}
5069
5070static inline bool
5071FTIHasSingleVoidArgument(DeclaratorChunk::FunctionTypeInfo &FTI) {
5072  return (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 &&
5073          FTI.ArgInfo[0].Param &&
5074          cast<ParmVarDecl>(FTI.ArgInfo[0].Param)->getType()->isVoidType());
5075}
5076
5077/// CheckDestructorDeclarator - Called by ActOnDeclarator to check
5078/// the well-formednes of the destructor declarator @p D with type @p
5079/// R. If there are any errors in the declarator, this routine will
5080/// emit diagnostics and set the declarator to invalid.  Even if this happens,
5081/// will be updated to reflect a well-formed type for the destructor and
5082/// returned.
5083QualType Sema::CheckDestructorDeclarator(Declarator &D, QualType R,
5084                                         StorageClass& SC) {
5085  // C++ [class.dtor]p1:
5086  //   [...] A typedef-name that names a class is a class-name
5087  //   (7.1.3); however, a typedef-name that names a class shall not
5088  //   be used as the identifier in the declarator for a destructor
5089  //   declaration.
5090  QualType DeclaratorType = GetTypeFromParser(D.getName().DestructorName);
5091  if (const TypedefType *TT = DeclaratorType->getAs<TypedefType>())
5092    Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name)
5093      << DeclaratorType << isa<TypeAliasDecl>(TT->getDecl());
5094  else if (const TemplateSpecializationType *TST =
5095             DeclaratorType->getAs<TemplateSpecializationType>())
5096    if (TST->isTypeAlias())
5097      Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name)
5098        << DeclaratorType << 1;
5099
5100  // C++ [class.dtor]p2:
5101  //   A destructor is used to destroy objects of its class type. A
5102  //   destructor takes no parameters, and no return type can be
5103  //   specified for it (not even void). The address of a destructor
5104  //   shall not be taken. A destructor shall not be static. A
5105  //   destructor can be invoked for a const, volatile or const
5106  //   volatile object. A destructor shall not be declared const,
5107  //   volatile or const volatile (9.3.2).
5108  if (SC == SC_Static) {
5109    if (!D.isInvalidType())
5110      Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be)
5111        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
5112        << SourceRange(D.getIdentifierLoc())
5113        << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
5114
5115    SC = SC_None;
5116  }
5117  if (D.getDeclSpec().hasTypeSpecifier() && !D.isInvalidType()) {
5118    // Destructors don't have return types, but the parser will
5119    // happily parse something like:
5120    //
5121    //   class X {
5122    //     float ~X();
5123    //   };
5124    //
5125    // The return type will be eliminated later.
5126    Diag(D.getIdentifierLoc(), diag::err_destructor_return_type)
5127      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
5128      << SourceRange(D.getIdentifierLoc());
5129  }
5130
5131  DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
5132  if (FTI.TypeQuals != 0 && !D.isInvalidType()) {
5133    if (FTI.TypeQuals & Qualifiers::Const)
5134      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
5135        << "const" << SourceRange(D.getIdentifierLoc());
5136    if (FTI.TypeQuals & Qualifiers::Volatile)
5137      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
5138        << "volatile" << SourceRange(D.getIdentifierLoc());
5139    if (FTI.TypeQuals & Qualifiers::Restrict)
5140      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
5141        << "restrict" << SourceRange(D.getIdentifierLoc());
5142    D.setInvalidType();
5143  }
5144
5145  // C++0x [class.dtor]p2:
5146  //   A destructor shall not be declared with a ref-qualifier.
5147  if (FTI.hasRefQualifier()) {
5148    Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_destructor)
5149      << FTI.RefQualifierIsLValueRef
5150      << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
5151    D.setInvalidType();
5152  }
5153
5154  // Make sure we don't have any parameters.
5155  if (FTI.NumArgs > 0 && !FTIHasSingleVoidArgument(FTI)) {
5156    Diag(D.getIdentifierLoc(), diag::err_destructor_with_params);
5157
5158    // Delete the parameters.
5159    FTI.freeArgs();
5160    D.setInvalidType();
5161  }
5162
5163  // Make sure the destructor isn't variadic.
5164  if (FTI.isVariadic) {
5165    Diag(D.getIdentifierLoc(), diag::err_destructor_variadic);
5166    D.setInvalidType();
5167  }
5168
5169  // Rebuild the function type "R" without any type qualifiers or
5170  // parameters (in case any of the errors above fired) and with
5171  // "void" as the return type, since destructors don't have return
5172  // types.
5173  if (!D.isInvalidType())
5174    return R;
5175
5176  const FunctionProtoType *Proto = R->getAs<FunctionProtoType>();
5177  FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
5178  EPI.Variadic = false;
5179  EPI.TypeQuals = 0;
5180  EPI.RefQualifier = RQ_None;
5181  return Context.getFunctionType(Context.VoidTy, 0, 0, EPI);
5182}
5183
5184/// CheckConversionDeclarator - Called by ActOnDeclarator to check the
5185/// well-formednes of the conversion function declarator @p D with
5186/// type @p R. If there are any errors in the declarator, this routine
5187/// will emit diagnostics and return true. Otherwise, it will return
5188/// false. Either way, the type @p R will be updated to reflect a
5189/// well-formed type for the conversion operator.
5190void Sema::CheckConversionDeclarator(Declarator &D, QualType &R,
5191                                     StorageClass& SC) {
5192  // C++ [class.conv.fct]p1:
5193  //   Neither parameter types nor return type can be specified. The
5194  //   type of a conversion function (8.3.5) is "function taking no
5195  //   parameter returning conversion-type-id."
5196  if (SC == SC_Static) {
5197    if (!D.isInvalidType())
5198      Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member)
5199        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
5200        << SourceRange(D.getIdentifierLoc());
5201    D.setInvalidType();
5202    SC = SC_None;
5203  }
5204
5205  QualType ConvType = GetTypeFromParser(D.getName().ConversionFunctionId);
5206
5207  if (D.getDeclSpec().hasTypeSpecifier() && !D.isInvalidType()) {
5208    // Conversion functions don't have return types, but the parser will
5209    // happily parse something like:
5210    //
5211    //   class X {
5212    //     float operator bool();
5213    //   };
5214    //
5215    // The return type will be changed later anyway.
5216    Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type)
5217      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
5218      << SourceRange(D.getIdentifierLoc());
5219    D.setInvalidType();
5220  }
5221
5222  const FunctionProtoType *Proto = R->getAs<FunctionProtoType>();
5223
5224  // Make sure we don't have any parameters.
5225  if (Proto->getNumArgs() > 0) {
5226    Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params);
5227
5228    // Delete the parameters.
5229    D.getFunctionTypeInfo().freeArgs();
5230    D.setInvalidType();
5231  } else if (Proto->isVariadic()) {
5232    Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic);
5233    D.setInvalidType();
5234  }
5235
5236  // Diagnose "&operator bool()" and other such nonsense.  This
5237  // is actually a gcc extension which we don't support.
5238  if (Proto->getResultType() != ConvType) {
5239    Diag(D.getIdentifierLoc(), diag::err_conv_function_with_complex_decl)
5240      << Proto->getResultType();
5241    D.setInvalidType();
5242    ConvType = Proto->getResultType();
5243  }
5244
5245  // C++ [class.conv.fct]p4:
5246  //   The conversion-type-id shall not represent a function type nor
5247  //   an array type.
5248  if (ConvType->isArrayType()) {
5249    Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array);
5250    ConvType = Context.getPointerType(ConvType);
5251    D.setInvalidType();
5252  } else if (ConvType->isFunctionType()) {
5253    Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function);
5254    ConvType = Context.getPointerType(ConvType);
5255    D.setInvalidType();
5256  }
5257
5258  // Rebuild the function type "R" without any parameters (in case any
5259  // of the errors above fired) and with the conversion type as the
5260  // return type.
5261  if (D.isInvalidType())
5262    R = Context.getFunctionType(ConvType, 0, 0, Proto->getExtProtoInfo());
5263
5264  // C++0x explicit conversion operators.
5265  if (D.getDeclSpec().isExplicitSpecified())
5266    Diag(D.getDeclSpec().getExplicitSpecLoc(),
5267         getLangOpts().CPlusPlus0x ?
5268           diag::warn_cxx98_compat_explicit_conversion_functions :
5269           diag::ext_explicit_conversion_functions)
5270      << SourceRange(D.getDeclSpec().getExplicitSpecLoc());
5271}
5272
5273/// ActOnConversionDeclarator - Called by ActOnDeclarator to complete
5274/// the declaration of the given C++ conversion function. This routine
5275/// is responsible for recording the conversion function in the C++
5276/// class, if possible.
5277Decl *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) {
5278  assert(Conversion && "Expected to receive a conversion function declaration");
5279
5280  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext());
5281
5282  // Make sure we aren't redeclaring the conversion function.
5283  QualType ConvType = Context.getCanonicalType(Conversion->getConversionType());
5284
5285  // C++ [class.conv.fct]p1:
5286  //   [...] A conversion function is never used to convert a
5287  //   (possibly cv-qualified) object to the (possibly cv-qualified)
5288  //   same object type (or a reference to it), to a (possibly
5289  //   cv-qualified) base class of that type (or a reference to it),
5290  //   or to (possibly cv-qualified) void.
5291  // FIXME: Suppress this warning if the conversion function ends up being a
5292  // virtual function that overrides a virtual function in a base class.
5293  QualType ClassType
5294    = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
5295  if (const ReferenceType *ConvTypeRef = ConvType->getAs<ReferenceType>())
5296    ConvType = ConvTypeRef->getPointeeType();
5297  if (Conversion->getTemplateSpecializationKind() != TSK_Undeclared &&
5298      Conversion->getTemplateSpecializationKind() != TSK_ExplicitSpecialization)
5299    /* Suppress diagnostics for instantiations. */;
5300  else if (ConvType->isRecordType()) {
5301    ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType();
5302    if (ConvType == ClassType)
5303      Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used)
5304        << ClassType;
5305    else if (IsDerivedFrom(ClassType, ConvType))
5306      Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used)
5307        <<  ClassType << ConvType;
5308  } else if (ConvType->isVoidType()) {
5309    Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used)
5310      << ClassType << ConvType;
5311  }
5312
5313  if (FunctionTemplateDecl *ConversionTemplate
5314                                = Conversion->getDescribedFunctionTemplate())
5315    return ConversionTemplate;
5316
5317  return Conversion;
5318}
5319
5320//===----------------------------------------------------------------------===//
5321// Namespace Handling
5322//===----------------------------------------------------------------------===//
5323
5324
5325
5326/// ActOnStartNamespaceDef - This is called at the start of a namespace
5327/// definition.
5328Decl *Sema::ActOnStartNamespaceDef(Scope *NamespcScope,
5329                                   SourceLocation InlineLoc,
5330                                   SourceLocation NamespaceLoc,
5331                                   SourceLocation IdentLoc,
5332                                   IdentifierInfo *II,
5333                                   SourceLocation LBrace,
5334                                   AttributeList *AttrList) {
5335  SourceLocation StartLoc = InlineLoc.isValid() ? InlineLoc : NamespaceLoc;
5336  // For anonymous namespace, take the location of the left brace.
5337  SourceLocation Loc = II ? IdentLoc : LBrace;
5338  bool IsInline = InlineLoc.isValid();
5339  bool IsInvalid = false;
5340  bool IsStd = false;
5341  bool AddToKnown = false;
5342  Scope *DeclRegionScope = NamespcScope->getParent();
5343
5344  NamespaceDecl *PrevNS = 0;
5345  if (II) {
5346    // C++ [namespace.def]p2:
5347    //   The identifier in an original-namespace-definition shall not
5348    //   have been previously defined in the declarative region in
5349    //   which the original-namespace-definition appears. The
5350    //   identifier in an original-namespace-definition is the name of
5351    //   the namespace. Subsequently in that declarative region, it is
5352    //   treated as an original-namespace-name.
5353    //
5354    // Since namespace names are unique in their scope, and we don't
5355    // look through using directives, just look for any ordinary names.
5356
5357    const unsigned IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Member |
5358    Decl::IDNS_Type | Decl::IDNS_Using | Decl::IDNS_Tag |
5359    Decl::IDNS_Namespace;
5360    NamedDecl *PrevDecl = 0;
5361    for (DeclContext::lookup_result R
5362         = CurContext->getRedeclContext()->lookup(II);
5363         R.first != R.second; ++R.first) {
5364      if ((*R.first)->getIdentifierNamespace() & IDNS) {
5365        PrevDecl = *R.first;
5366        break;
5367      }
5368    }
5369
5370    PrevNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl);
5371
5372    if (PrevNS) {
5373      // This is an extended namespace definition.
5374      if (IsInline != PrevNS->isInline()) {
5375        // inline-ness must match
5376        if (PrevNS->isInline()) {
5377          // The user probably just forgot the 'inline', so suggest that it
5378          // be added back.
5379          Diag(Loc, diag::warn_inline_namespace_reopened_noninline)
5380            << FixItHint::CreateInsertion(NamespaceLoc, "inline ");
5381        } else {
5382          Diag(Loc, diag::err_inline_namespace_mismatch)
5383            << IsInline;
5384        }
5385        Diag(PrevNS->getLocation(), diag::note_previous_definition);
5386
5387        IsInline = PrevNS->isInline();
5388      }
5389    } else if (PrevDecl) {
5390      // This is an invalid name redefinition.
5391      Diag(Loc, diag::err_redefinition_different_kind)
5392        << II;
5393      Diag(PrevDecl->getLocation(), diag::note_previous_definition);
5394      IsInvalid = true;
5395      // Continue on to push Namespc as current DeclContext and return it.
5396    } else if (II->isStr("std") &&
5397               CurContext->getRedeclContext()->isTranslationUnit()) {
5398      // This is the first "real" definition of the namespace "std", so update
5399      // our cache of the "std" namespace to point at this definition.
5400      PrevNS = getStdNamespace();
5401      IsStd = true;
5402      AddToKnown = !IsInline;
5403    } else {
5404      // We've seen this namespace for the first time.
5405      AddToKnown = !IsInline;
5406    }
5407  } else {
5408    // Anonymous namespaces.
5409
5410    // Determine whether the parent already has an anonymous namespace.
5411    DeclContext *Parent = CurContext->getRedeclContext();
5412    if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
5413      PrevNS = TU->getAnonymousNamespace();
5414    } else {
5415      NamespaceDecl *ND = cast<NamespaceDecl>(Parent);
5416      PrevNS = ND->getAnonymousNamespace();
5417    }
5418
5419    if (PrevNS && IsInline != PrevNS->isInline()) {
5420      // inline-ness must match
5421      Diag(Loc, diag::err_inline_namespace_mismatch)
5422        << IsInline;
5423      Diag(PrevNS->getLocation(), diag::note_previous_definition);
5424
5425      // Recover by ignoring the new namespace's inline status.
5426      IsInline = PrevNS->isInline();
5427    }
5428  }
5429
5430  NamespaceDecl *Namespc = NamespaceDecl::Create(Context, CurContext, IsInline,
5431                                                 StartLoc, Loc, II, PrevNS);
5432  if (IsInvalid)
5433    Namespc->setInvalidDecl();
5434
5435  ProcessDeclAttributeList(DeclRegionScope, Namespc, AttrList);
5436
5437  // FIXME: Should we be merging attributes?
5438  if (const VisibilityAttr *Attr = Namespc->getAttr<VisibilityAttr>())
5439    PushNamespaceVisibilityAttr(Attr, Loc);
5440
5441  if (IsStd)
5442    StdNamespace = Namespc;
5443  if (AddToKnown)
5444    KnownNamespaces[Namespc] = false;
5445
5446  if (II) {
5447    PushOnScopeChains(Namespc, DeclRegionScope);
5448  } else {
5449    // Link the anonymous namespace into its parent.
5450    DeclContext *Parent = CurContext->getRedeclContext();
5451    if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
5452      TU->setAnonymousNamespace(Namespc);
5453    } else {
5454      cast<NamespaceDecl>(Parent)->setAnonymousNamespace(Namespc);
5455    }
5456
5457    CurContext->addDecl(Namespc);
5458
5459    // C++ [namespace.unnamed]p1.  An unnamed-namespace-definition
5460    //   behaves as if it were replaced by
5461    //     namespace unique { /* empty body */ }
5462    //     using namespace unique;
5463    //     namespace unique { namespace-body }
5464    //   where all occurrences of 'unique' in a translation unit are
5465    //   replaced by the same identifier and this identifier differs
5466    //   from all other identifiers in the entire program.
5467
5468    // We just create the namespace with an empty name and then add an
5469    // implicit using declaration, just like the standard suggests.
5470    //
5471    // CodeGen enforces the "universally unique" aspect by giving all
5472    // declarations semantically contained within an anonymous
5473    // namespace internal linkage.
5474
5475    if (!PrevNS) {
5476      UsingDirectiveDecl* UD
5477        = UsingDirectiveDecl::Create(Context, CurContext,
5478                                     /* 'using' */ LBrace,
5479                                     /* 'namespace' */ SourceLocation(),
5480                                     /* qualifier */ NestedNameSpecifierLoc(),
5481                                     /* identifier */ SourceLocation(),
5482                                     Namespc,
5483                                     /* Ancestor */ CurContext);
5484      UD->setImplicit();
5485      CurContext->addDecl(UD);
5486    }
5487  }
5488
5489  ActOnDocumentableDecl(Namespc);
5490
5491  // Although we could have an invalid decl (i.e. the namespace name is a
5492  // redefinition), push it as current DeclContext and try to continue parsing.
5493  // FIXME: We should be able to push Namespc here, so that the each DeclContext
5494  // for the namespace has the declarations that showed up in that particular
5495  // namespace definition.
5496  PushDeclContext(NamespcScope, Namespc);
5497  return Namespc;
5498}
5499
5500/// getNamespaceDecl - Returns the namespace a decl represents. If the decl
5501/// is a namespace alias, returns the namespace it points to.
5502static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) {
5503  if (NamespaceAliasDecl *AD = dyn_cast_or_null<NamespaceAliasDecl>(D))
5504    return AD->getNamespace();
5505  return dyn_cast_or_null<NamespaceDecl>(D);
5506}
5507
5508/// ActOnFinishNamespaceDef - This callback is called after a namespace is
5509/// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef.
5510void Sema::ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace) {
5511  NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl);
5512  assert(Namespc && "Invalid parameter, expected NamespaceDecl");
5513  Namespc->setRBraceLoc(RBrace);
5514  PopDeclContext();
5515  if (Namespc->hasAttr<VisibilityAttr>())
5516    PopPragmaVisibility(true, RBrace);
5517}
5518
5519CXXRecordDecl *Sema::getStdBadAlloc() const {
5520  return cast_or_null<CXXRecordDecl>(
5521                                  StdBadAlloc.get(Context.getExternalSource()));
5522}
5523
5524NamespaceDecl *Sema::getStdNamespace() const {
5525  return cast_or_null<NamespaceDecl>(
5526                                 StdNamespace.get(Context.getExternalSource()));
5527}
5528
5529/// \brief Retrieve the special "std" namespace, which may require us to
5530/// implicitly define the namespace.
5531NamespaceDecl *Sema::getOrCreateStdNamespace() {
5532  if (!StdNamespace) {
5533    // The "std" namespace has not yet been defined, so build one implicitly.
5534    StdNamespace = NamespaceDecl::Create(Context,
5535                                         Context.getTranslationUnitDecl(),
5536                                         /*Inline=*/false,
5537                                         SourceLocation(), SourceLocation(),
5538                                         &PP.getIdentifierTable().get("std"),
5539                                         /*PrevDecl=*/0);
5540    getStdNamespace()->setImplicit(true);
5541  }
5542
5543  return getStdNamespace();
5544}
5545
5546bool Sema::isStdInitializerList(QualType Ty, QualType *Element) {
5547  assert(getLangOpts().CPlusPlus &&
5548         "Looking for std::initializer_list outside of C++.");
5549
5550  // We're looking for implicit instantiations of
5551  // template <typename E> class std::initializer_list.
5552
5553  if (!StdNamespace) // If we haven't seen namespace std yet, this can't be it.
5554    return false;
5555
5556  ClassTemplateDecl *Template = 0;
5557  const TemplateArgument *Arguments = 0;
5558
5559  if (const RecordType *RT = Ty->getAs<RecordType>()) {
5560
5561    ClassTemplateSpecializationDecl *Specialization =
5562        dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl());
5563    if (!Specialization)
5564      return false;
5565
5566    Template = Specialization->getSpecializedTemplate();
5567    Arguments = Specialization->getTemplateArgs().data();
5568  } else if (const TemplateSpecializationType *TST =
5569                 Ty->getAs<TemplateSpecializationType>()) {
5570    Template = dyn_cast_or_null<ClassTemplateDecl>(
5571        TST->getTemplateName().getAsTemplateDecl());
5572    Arguments = TST->getArgs();
5573  }
5574  if (!Template)
5575    return false;
5576
5577  if (!StdInitializerList) {
5578    // Haven't recognized std::initializer_list yet, maybe this is it.
5579    CXXRecordDecl *TemplateClass = Template->getTemplatedDecl();
5580    if (TemplateClass->getIdentifier() !=
5581            &PP.getIdentifierTable().get("initializer_list") ||
5582        !getStdNamespace()->InEnclosingNamespaceSetOf(
5583            TemplateClass->getDeclContext()))
5584      return false;
5585    // This is a template called std::initializer_list, but is it the right
5586    // template?
5587    TemplateParameterList *Params = Template->getTemplateParameters();
5588    if (Params->getMinRequiredArguments() != 1)
5589      return false;
5590    if (!isa<TemplateTypeParmDecl>(Params->getParam(0)))
5591      return false;
5592
5593    // It's the right template.
5594    StdInitializerList = Template;
5595  }
5596
5597  if (Template != StdInitializerList)
5598    return false;
5599
5600  // This is an instance of std::initializer_list. Find the argument type.
5601  if (Element)
5602    *Element = Arguments[0].getAsType();
5603  return true;
5604}
5605
5606static ClassTemplateDecl *LookupStdInitializerList(Sema &S, SourceLocation Loc){
5607  NamespaceDecl *Std = S.getStdNamespace();
5608  if (!Std) {
5609    S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
5610    return 0;
5611  }
5612
5613  LookupResult Result(S, &S.PP.getIdentifierTable().get("initializer_list"),
5614                      Loc, Sema::LookupOrdinaryName);
5615  if (!S.LookupQualifiedName(Result, Std)) {
5616    S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
5617    return 0;
5618  }
5619  ClassTemplateDecl *Template = Result.getAsSingle<ClassTemplateDecl>();
5620  if (!Template) {
5621    Result.suppressDiagnostics();
5622    // We found something weird. Complain about the first thing we found.
5623    NamedDecl *Found = *Result.begin();
5624    S.Diag(Found->getLocation(), diag::err_malformed_std_initializer_list);
5625    return 0;
5626  }
5627
5628  // We found some template called std::initializer_list. Now verify that it's
5629  // correct.
5630  TemplateParameterList *Params = Template->getTemplateParameters();
5631  if (Params->getMinRequiredArguments() != 1 ||
5632      !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
5633    S.Diag(Template->getLocation(), diag::err_malformed_std_initializer_list);
5634    return 0;
5635  }
5636
5637  return Template;
5638}
5639
5640QualType Sema::BuildStdInitializerList(QualType Element, SourceLocation Loc) {
5641  if (!StdInitializerList) {
5642    StdInitializerList = LookupStdInitializerList(*this, Loc);
5643    if (!StdInitializerList)
5644      return QualType();
5645  }
5646
5647  TemplateArgumentListInfo Args(Loc, Loc);
5648  Args.addArgument(TemplateArgumentLoc(TemplateArgument(Element),
5649                                       Context.getTrivialTypeSourceInfo(Element,
5650                                                                        Loc)));
5651  return Context.getCanonicalType(
5652      CheckTemplateIdType(TemplateName(StdInitializerList), Loc, Args));
5653}
5654
5655bool Sema::isInitListConstructor(const CXXConstructorDecl* Ctor) {
5656  // C++ [dcl.init.list]p2:
5657  //   A constructor is an initializer-list constructor if its first parameter
5658  //   is of type std::initializer_list<E> or reference to possibly cv-qualified
5659  //   std::initializer_list<E> for some type E, and either there are no other
5660  //   parameters or else all other parameters have default arguments.
5661  if (Ctor->getNumParams() < 1 ||
5662      (Ctor->getNumParams() > 1 && !Ctor->getParamDecl(1)->hasDefaultArg()))
5663    return false;
5664
5665  QualType ArgType = Ctor->getParamDecl(0)->getType();
5666  if (const ReferenceType *RT = ArgType->getAs<ReferenceType>())
5667    ArgType = RT->getPointeeType().getUnqualifiedType();
5668
5669  return isStdInitializerList(ArgType, 0);
5670}
5671
5672/// \brief Determine whether a using statement is in a context where it will be
5673/// apply in all contexts.
5674static bool IsUsingDirectiveInToplevelContext(DeclContext *CurContext) {
5675  switch (CurContext->getDeclKind()) {
5676    case Decl::TranslationUnit:
5677      return true;
5678    case Decl::LinkageSpec:
5679      return IsUsingDirectiveInToplevelContext(CurContext->getParent());
5680    default:
5681      return false;
5682  }
5683}
5684
5685namespace {
5686
5687// Callback to only accept typo corrections that are namespaces.
5688class NamespaceValidatorCCC : public CorrectionCandidateCallback {
5689 public:
5690  virtual bool ValidateCandidate(const TypoCorrection &candidate) {
5691    if (NamedDecl *ND = candidate.getCorrectionDecl()) {
5692      return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND);
5693    }
5694    return false;
5695  }
5696};
5697
5698}
5699
5700static bool TryNamespaceTypoCorrection(Sema &S, LookupResult &R, Scope *Sc,
5701                                       CXXScopeSpec &SS,
5702                                       SourceLocation IdentLoc,
5703                                       IdentifierInfo *Ident) {
5704  NamespaceValidatorCCC Validator;
5705  R.clear();
5706  if (TypoCorrection Corrected = S.CorrectTypo(R.getLookupNameInfo(),
5707                                               R.getLookupKind(), Sc, &SS,
5708                                               Validator)) {
5709    std::string CorrectedStr(Corrected.getAsString(S.getLangOpts()));
5710    std::string CorrectedQuotedStr(Corrected.getQuoted(S.getLangOpts()));
5711    if (DeclContext *DC = S.computeDeclContext(SS, false))
5712      S.Diag(IdentLoc, diag::err_using_directive_member_suggest)
5713        << Ident << DC << CorrectedQuotedStr << SS.getRange()
5714        << FixItHint::CreateReplacement(IdentLoc, CorrectedStr);
5715    else
5716      S.Diag(IdentLoc, diag::err_using_directive_suggest)
5717        << Ident << CorrectedQuotedStr
5718        << FixItHint::CreateReplacement(IdentLoc, CorrectedStr);
5719
5720    S.Diag(Corrected.getCorrectionDecl()->getLocation(),
5721         diag::note_namespace_defined_here) << CorrectedQuotedStr;
5722
5723    R.addDecl(Corrected.getCorrectionDecl());
5724    return true;
5725  }
5726  return false;
5727}
5728
5729Decl *Sema::ActOnUsingDirective(Scope *S,
5730                                          SourceLocation UsingLoc,
5731                                          SourceLocation NamespcLoc,
5732                                          CXXScopeSpec &SS,
5733                                          SourceLocation IdentLoc,
5734                                          IdentifierInfo *NamespcName,
5735                                          AttributeList *AttrList) {
5736  assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
5737  assert(NamespcName && "Invalid NamespcName.");
5738  assert(IdentLoc.isValid() && "Invalid NamespceName location.");
5739
5740  // This can only happen along a recovery path.
5741  while (S->getFlags() & Scope::TemplateParamScope)
5742    S = S->getParent();
5743  assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
5744
5745  UsingDirectiveDecl *UDir = 0;
5746  NestedNameSpecifier *Qualifier = 0;
5747  if (SS.isSet())
5748    Qualifier = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
5749
5750  // Lookup namespace name.
5751  LookupResult R(*this, NamespcName, IdentLoc, LookupNamespaceName);
5752  LookupParsedName(R, S, &SS);
5753  if (R.isAmbiguous())
5754    return 0;
5755
5756  if (R.empty()) {
5757    R.clear();
5758    // Allow "using namespace std;" or "using namespace ::std;" even if
5759    // "std" hasn't been defined yet, for GCC compatibility.
5760    if ((!Qualifier || Qualifier->getKind() == NestedNameSpecifier::Global) &&
5761        NamespcName->isStr("std")) {
5762      Diag(IdentLoc, diag::ext_using_undefined_std);
5763      R.addDecl(getOrCreateStdNamespace());
5764      R.resolveKind();
5765    }
5766    // Otherwise, attempt typo correction.
5767    else TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, NamespcName);
5768  }
5769
5770  if (!R.empty()) {
5771    NamedDecl *Named = R.getFoundDecl();
5772    assert((isa<NamespaceDecl>(Named) || isa<NamespaceAliasDecl>(Named))
5773        && "expected namespace decl");
5774    // C++ [namespace.udir]p1:
5775    //   A using-directive specifies that the names in the nominated
5776    //   namespace can be used in the scope in which the
5777    //   using-directive appears after the using-directive. During
5778    //   unqualified name lookup (3.4.1), the names appear as if they
5779    //   were declared in the nearest enclosing namespace which
5780    //   contains both the using-directive and the nominated
5781    //   namespace. [Note: in this context, "contains" means "contains
5782    //   directly or indirectly". ]
5783
5784    // Find enclosing context containing both using-directive and
5785    // nominated namespace.
5786    NamespaceDecl *NS = getNamespaceDecl(Named);
5787    DeclContext *CommonAncestor = cast<DeclContext>(NS);
5788    while (CommonAncestor && !CommonAncestor->Encloses(CurContext))
5789      CommonAncestor = CommonAncestor->getParent();
5790
5791    UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc, NamespcLoc,
5792                                      SS.getWithLocInContext(Context),
5793                                      IdentLoc, Named, CommonAncestor);
5794
5795    if (IsUsingDirectiveInToplevelContext(CurContext) &&
5796        !SourceMgr.isFromMainFile(SourceMgr.getExpansionLoc(IdentLoc))) {
5797      Diag(IdentLoc, diag::warn_using_directive_in_header);
5798    }
5799
5800    PushUsingDirective(S, UDir);
5801  } else {
5802    Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
5803  }
5804
5805  // FIXME: We ignore attributes for now.
5806  return UDir;
5807}
5808
5809void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) {
5810  // If the scope has an associated entity and the using directive is at
5811  // namespace or translation unit scope, add the UsingDirectiveDecl into
5812  // its lookup structure so qualified name lookup can find it.
5813  DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity());
5814  if (Ctx && !Ctx->isFunctionOrMethod())
5815    Ctx->addDecl(UDir);
5816  else
5817    // Otherwise, it is at block sope. The using-directives will affect lookup
5818    // only to the end of the scope.
5819    S->PushUsingDirective(UDir);
5820}
5821
5822
5823Decl *Sema::ActOnUsingDeclaration(Scope *S,
5824                                  AccessSpecifier AS,
5825                                  bool HasUsingKeyword,
5826                                  SourceLocation UsingLoc,
5827                                  CXXScopeSpec &SS,
5828                                  UnqualifiedId &Name,
5829                                  AttributeList *AttrList,
5830                                  bool IsTypeName,
5831                                  SourceLocation TypenameLoc) {
5832  assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
5833
5834  switch (Name.getKind()) {
5835  case UnqualifiedId::IK_ImplicitSelfParam:
5836  case UnqualifiedId::IK_Identifier:
5837  case UnqualifiedId::IK_OperatorFunctionId:
5838  case UnqualifiedId::IK_LiteralOperatorId:
5839  case UnqualifiedId::IK_ConversionFunctionId:
5840    break;
5841
5842  case UnqualifiedId::IK_ConstructorName:
5843  case UnqualifiedId::IK_ConstructorTemplateId:
5844    // C++11 inheriting constructors.
5845    Diag(Name.getLocStart(),
5846         getLangOpts().CPlusPlus0x ?
5847           // FIXME: Produce warn_cxx98_compat_using_decl_constructor
5848           //        instead once inheriting constructors work.
5849           diag::err_using_decl_constructor_unsupported :
5850           diag::err_using_decl_constructor)
5851      << SS.getRange();
5852
5853    if (getLangOpts().CPlusPlus0x) break;
5854
5855    return 0;
5856
5857  case UnqualifiedId::IK_DestructorName:
5858    Diag(Name.getLocStart(), diag::err_using_decl_destructor)
5859      << SS.getRange();
5860    return 0;
5861
5862  case UnqualifiedId::IK_TemplateId:
5863    Diag(Name.getLocStart(), diag::err_using_decl_template_id)
5864      << SourceRange(Name.TemplateId->LAngleLoc, Name.TemplateId->RAngleLoc);
5865    return 0;
5866  }
5867
5868  DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name);
5869  DeclarationName TargetName = TargetNameInfo.getName();
5870  if (!TargetName)
5871    return 0;
5872
5873  // Warn about using declarations.
5874  // TODO: store that the declaration was written without 'using' and
5875  // talk about access decls instead of using decls in the
5876  // diagnostics.
5877  if (!HasUsingKeyword) {
5878    UsingLoc = Name.getLocStart();
5879
5880    Diag(UsingLoc, diag::warn_access_decl_deprecated)
5881      << FixItHint::CreateInsertion(SS.getRange().getBegin(), "using ");
5882  }
5883
5884  if (DiagnoseUnexpandedParameterPack(SS, UPPC_UsingDeclaration) ||
5885      DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC_UsingDeclaration))
5886    return 0;
5887
5888  NamedDecl *UD = BuildUsingDeclaration(S, AS, UsingLoc, SS,
5889                                        TargetNameInfo, AttrList,
5890                                        /* IsInstantiation */ false,
5891                                        IsTypeName, TypenameLoc);
5892  if (UD)
5893    PushOnScopeChains(UD, S, /*AddToContext*/ false);
5894
5895  return UD;
5896}
5897
5898/// \brief Determine whether a using declaration considers the given
5899/// declarations as "equivalent", e.g., if they are redeclarations of
5900/// the same entity or are both typedefs of the same type.
5901static bool
5902IsEquivalentForUsingDecl(ASTContext &Context, NamedDecl *D1, NamedDecl *D2,
5903                         bool &SuppressRedeclaration) {
5904  if (D1->getCanonicalDecl() == D2->getCanonicalDecl()) {
5905    SuppressRedeclaration = false;
5906    return true;
5907  }
5908
5909  if (TypedefNameDecl *TD1 = dyn_cast<TypedefNameDecl>(D1))
5910    if (TypedefNameDecl *TD2 = dyn_cast<TypedefNameDecl>(D2)) {
5911      SuppressRedeclaration = true;
5912      return Context.hasSameType(TD1->getUnderlyingType(),
5913                                 TD2->getUnderlyingType());
5914    }
5915
5916  return false;
5917}
5918
5919
5920/// Determines whether to create a using shadow decl for a particular
5921/// decl, given the set of decls existing prior to this using lookup.
5922bool Sema::CheckUsingShadowDecl(UsingDecl *Using, NamedDecl *Orig,
5923                                const LookupResult &Previous) {
5924  // Diagnose finding a decl which is not from a base class of the
5925  // current class.  We do this now because there are cases where this
5926  // function will silently decide not to build a shadow decl, which
5927  // will pre-empt further diagnostics.
5928  //
5929  // We don't need to do this in C++0x because we do the check once on
5930  // the qualifier.
5931  //
5932  // FIXME: diagnose the following if we care enough:
5933  //   struct A { int foo; };
5934  //   struct B : A { using A::foo; };
5935  //   template <class T> struct C : A {};
5936  //   template <class T> struct D : C<T> { using B::foo; } // <---
5937  // This is invalid (during instantiation) in C++03 because B::foo
5938  // resolves to the using decl in B, which is not a base class of D<T>.
5939  // We can't diagnose it immediately because C<T> is an unknown
5940  // specialization.  The UsingShadowDecl in D<T> then points directly
5941  // to A::foo, which will look well-formed when we instantiate.
5942  // The right solution is to not collapse the shadow-decl chain.
5943  if (!getLangOpts().CPlusPlus0x && CurContext->isRecord()) {
5944    DeclContext *OrigDC = Orig->getDeclContext();
5945
5946    // Handle enums and anonymous structs.
5947    if (isa<EnumDecl>(OrigDC)) OrigDC = OrigDC->getParent();
5948    CXXRecordDecl *OrigRec = cast<CXXRecordDecl>(OrigDC);
5949    while (OrigRec->isAnonymousStructOrUnion())
5950      OrigRec = cast<CXXRecordDecl>(OrigRec->getDeclContext());
5951
5952    if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(OrigRec)) {
5953      if (OrigDC == CurContext) {
5954        Diag(Using->getLocation(),
5955             diag::err_using_decl_nested_name_specifier_is_current_class)
5956          << Using->getQualifierLoc().getSourceRange();
5957        Diag(Orig->getLocation(), diag::note_using_decl_target);
5958        return true;
5959      }
5960
5961      Diag(Using->getQualifierLoc().getBeginLoc(),
5962           diag::err_using_decl_nested_name_specifier_is_not_base_class)
5963        << Using->getQualifier()
5964        << cast<CXXRecordDecl>(CurContext)
5965        << Using->getQualifierLoc().getSourceRange();
5966      Diag(Orig->getLocation(), diag::note_using_decl_target);
5967      return true;
5968    }
5969  }
5970
5971  if (Previous.empty()) return false;
5972
5973  NamedDecl *Target = Orig;
5974  if (isa<UsingShadowDecl>(Target))
5975    Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
5976
5977  // If the target happens to be one of the previous declarations, we
5978  // don't have a conflict.
5979  //
5980  // FIXME: but we might be increasing its access, in which case we
5981  // should redeclare it.
5982  NamedDecl *NonTag = 0, *Tag = 0;
5983  for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
5984         I != E; ++I) {
5985    NamedDecl *D = (*I)->getUnderlyingDecl();
5986    bool Result;
5987    if (IsEquivalentForUsingDecl(Context, D, Target, Result))
5988      return Result;
5989
5990    (isa<TagDecl>(D) ? Tag : NonTag) = D;
5991  }
5992
5993  if (Target->isFunctionOrFunctionTemplate()) {
5994    FunctionDecl *FD;
5995    if (isa<FunctionTemplateDecl>(Target))
5996      FD = cast<FunctionTemplateDecl>(Target)->getTemplatedDecl();
5997    else
5998      FD = cast<FunctionDecl>(Target);
5999
6000    NamedDecl *OldDecl = 0;
6001    switch (CheckOverload(0, FD, Previous, OldDecl, /*IsForUsingDecl*/ true)) {
6002    case Ovl_Overload:
6003      return false;
6004
6005    case Ovl_NonFunction:
6006      Diag(Using->getLocation(), diag::err_using_decl_conflict);
6007      break;
6008
6009    // We found a decl with the exact signature.
6010    case Ovl_Match:
6011      // If we're in a record, we want to hide the target, so we
6012      // return true (without a diagnostic) to tell the caller not to
6013      // build a shadow decl.
6014      if (CurContext->isRecord())
6015        return true;
6016
6017      // If we're not in a record, this is an error.
6018      Diag(Using->getLocation(), diag::err_using_decl_conflict);
6019      break;
6020    }
6021
6022    Diag(Target->getLocation(), diag::note_using_decl_target);
6023    Diag(OldDecl->getLocation(), diag::note_using_decl_conflict);
6024    return true;
6025  }
6026
6027  // Target is not a function.
6028
6029  if (isa<TagDecl>(Target)) {
6030    // No conflict between a tag and a non-tag.
6031    if (!Tag) return false;
6032
6033    Diag(Using->getLocation(), diag::err_using_decl_conflict);
6034    Diag(Target->getLocation(), diag::note_using_decl_target);
6035    Diag(Tag->getLocation(), diag::note_using_decl_conflict);
6036    return true;
6037  }
6038
6039  // No conflict between a tag and a non-tag.
6040  if (!NonTag) return false;
6041
6042  Diag(Using->getLocation(), diag::err_using_decl_conflict);
6043  Diag(Target->getLocation(), diag::note_using_decl_target);
6044  Diag(NonTag->getLocation(), diag::note_using_decl_conflict);
6045  return true;
6046}
6047
6048/// Builds a shadow declaration corresponding to a 'using' declaration.
6049UsingShadowDecl *Sema::BuildUsingShadowDecl(Scope *S,
6050                                            UsingDecl *UD,
6051                                            NamedDecl *Orig) {
6052
6053  // If we resolved to another shadow declaration, just coalesce them.
6054  NamedDecl *Target = Orig;
6055  if (isa<UsingShadowDecl>(Target)) {
6056    Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
6057    assert(!isa<UsingShadowDecl>(Target) && "nested shadow declaration");
6058  }
6059
6060  UsingShadowDecl *Shadow
6061    = UsingShadowDecl::Create(Context, CurContext,
6062                              UD->getLocation(), UD, Target);
6063  UD->addShadowDecl(Shadow);
6064
6065  Shadow->setAccess(UD->getAccess());
6066  if (Orig->isInvalidDecl() || UD->isInvalidDecl())
6067    Shadow->setInvalidDecl();
6068
6069  if (S)
6070    PushOnScopeChains(Shadow, S);
6071  else
6072    CurContext->addDecl(Shadow);
6073
6074
6075  return Shadow;
6076}
6077
6078/// Hides a using shadow declaration.  This is required by the current
6079/// using-decl implementation when a resolvable using declaration in a
6080/// class is followed by a declaration which would hide or override
6081/// one or more of the using decl's targets; for example:
6082///
6083///   struct Base { void foo(int); };
6084///   struct Derived : Base {
6085///     using Base::foo;
6086///     void foo(int);
6087///   };
6088///
6089/// The governing language is C++03 [namespace.udecl]p12:
6090///
6091///   When a using-declaration brings names from a base class into a
6092///   derived class scope, member functions in the derived class
6093///   override and/or hide member functions with the same name and
6094///   parameter types in a base class (rather than conflicting).
6095///
6096/// There are two ways to implement this:
6097///   (1) optimistically create shadow decls when they're not hidden
6098///       by existing declarations, or
6099///   (2) don't create any shadow decls (or at least don't make them
6100///       visible) until we've fully parsed/instantiated the class.
6101/// The problem with (1) is that we might have to retroactively remove
6102/// a shadow decl, which requires several O(n) operations because the
6103/// decl structures are (very reasonably) not designed for removal.
6104/// (2) avoids this but is very fiddly and phase-dependent.
6105void Sema::HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow) {
6106  if (Shadow->getDeclName().getNameKind() ==
6107        DeclarationName::CXXConversionFunctionName)
6108    cast<CXXRecordDecl>(Shadow->getDeclContext())->removeConversion(Shadow);
6109
6110  // Remove it from the DeclContext...
6111  Shadow->getDeclContext()->removeDecl(Shadow);
6112
6113  // ...and the scope, if applicable...
6114  if (S) {
6115    S->RemoveDecl(Shadow);
6116    IdResolver.RemoveDecl(Shadow);
6117  }
6118
6119  // ...and the using decl.
6120  Shadow->getUsingDecl()->removeShadowDecl(Shadow);
6121
6122  // TODO: complain somehow if Shadow was used.  It shouldn't
6123  // be possible for this to happen, because...?
6124}
6125
6126/// Builds a using declaration.
6127///
6128/// \param IsInstantiation - Whether this call arises from an
6129///   instantiation of an unresolved using declaration.  We treat
6130///   the lookup differently for these declarations.
6131NamedDecl *Sema::BuildUsingDeclaration(Scope *S, AccessSpecifier AS,
6132                                       SourceLocation UsingLoc,
6133                                       CXXScopeSpec &SS,
6134                                       const DeclarationNameInfo &NameInfo,
6135                                       AttributeList *AttrList,
6136                                       bool IsInstantiation,
6137                                       bool IsTypeName,
6138                                       SourceLocation TypenameLoc) {
6139  assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
6140  SourceLocation IdentLoc = NameInfo.getLoc();
6141  assert(IdentLoc.isValid() && "Invalid TargetName location.");
6142
6143  // FIXME: We ignore attributes for now.
6144
6145  if (SS.isEmpty()) {
6146    Diag(IdentLoc, diag::err_using_requires_qualname);
6147    return 0;
6148  }
6149
6150  // Do the redeclaration lookup in the current scope.
6151  LookupResult Previous(*this, NameInfo, LookupUsingDeclName,
6152                        ForRedeclaration);
6153  Previous.setHideTags(false);
6154  if (S) {
6155    LookupName(Previous, S);
6156
6157    // It is really dumb that we have to do this.
6158    LookupResult::Filter F = Previous.makeFilter();
6159    while (F.hasNext()) {
6160      NamedDecl *D = F.next();
6161      if (!isDeclInScope(D, CurContext, S))
6162        F.erase();
6163    }
6164    F.done();
6165  } else {
6166    assert(IsInstantiation && "no scope in non-instantiation");
6167    assert(CurContext->isRecord() && "scope not record in instantiation");
6168    LookupQualifiedName(Previous, CurContext);
6169  }
6170
6171  // Check for invalid redeclarations.
6172  if (CheckUsingDeclRedeclaration(UsingLoc, IsTypeName, SS, IdentLoc, Previous))
6173    return 0;
6174
6175  // Check for bad qualifiers.
6176  if (CheckUsingDeclQualifier(UsingLoc, SS, IdentLoc))
6177    return 0;
6178
6179  DeclContext *LookupContext = computeDeclContext(SS);
6180  NamedDecl *D;
6181  NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
6182  if (!LookupContext) {
6183    if (IsTypeName) {
6184      // FIXME: not all declaration name kinds are legal here
6185      D = UnresolvedUsingTypenameDecl::Create(Context, CurContext,
6186                                              UsingLoc, TypenameLoc,
6187                                              QualifierLoc,
6188                                              IdentLoc, NameInfo.getName());
6189    } else {
6190      D = UnresolvedUsingValueDecl::Create(Context, CurContext, UsingLoc,
6191                                           QualifierLoc, NameInfo);
6192    }
6193  } else {
6194    D = UsingDecl::Create(Context, CurContext, UsingLoc, QualifierLoc,
6195                          NameInfo, IsTypeName);
6196  }
6197  D->setAccess(AS);
6198  CurContext->addDecl(D);
6199
6200  if (!LookupContext) return D;
6201  UsingDecl *UD = cast<UsingDecl>(D);
6202
6203  if (RequireCompleteDeclContext(SS, LookupContext)) {
6204    UD->setInvalidDecl();
6205    return UD;
6206  }
6207
6208  // The normal rules do not apply to inheriting constructor declarations.
6209  if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName) {
6210    if (CheckInheritingConstructorUsingDecl(UD))
6211      UD->setInvalidDecl();
6212    return UD;
6213  }
6214
6215  // Otherwise, look up the target name.
6216
6217  LookupResult R(*this, NameInfo, LookupOrdinaryName);
6218
6219  // Unlike most lookups, we don't always want to hide tag
6220  // declarations: tag names are visible through the using declaration
6221  // even if hidden by ordinary names, *except* in a dependent context
6222  // where it's important for the sanity of two-phase lookup.
6223  if (!IsInstantiation)
6224    R.setHideTags(false);
6225
6226  // For the purposes of this lookup, we have a base object type
6227  // equal to that of the current context.
6228  if (CurContext->isRecord()) {
6229    R.setBaseObjectType(
6230                   Context.getTypeDeclType(cast<CXXRecordDecl>(CurContext)));
6231  }
6232
6233  LookupQualifiedName(R, LookupContext);
6234
6235  if (R.empty()) {
6236    Diag(IdentLoc, diag::err_no_member)
6237      << NameInfo.getName() << LookupContext << SS.getRange();
6238    UD->setInvalidDecl();
6239    return UD;
6240  }
6241
6242  if (R.isAmbiguous()) {
6243    UD->setInvalidDecl();
6244    return UD;
6245  }
6246
6247  if (IsTypeName) {
6248    // If we asked for a typename and got a non-type decl, error out.
6249    if (!R.getAsSingle<TypeDecl>()) {
6250      Diag(IdentLoc, diag::err_using_typename_non_type);
6251      for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
6252        Diag((*I)->getUnderlyingDecl()->getLocation(),
6253             diag::note_using_decl_target);
6254      UD->setInvalidDecl();
6255      return UD;
6256    }
6257  } else {
6258    // If we asked for a non-typename and we got a type, error out,
6259    // but only if this is an instantiation of an unresolved using
6260    // decl.  Otherwise just silently find the type name.
6261    if (IsInstantiation && R.getAsSingle<TypeDecl>()) {
6262      Diag(IdentLoc, diag::err_using_dependent_value_is_type);
6263      Diag(R.getFoundDecl()->getLocation(), diag::note_using_decl_target);
6264      UD->setInvalidDecl();
6265      return UD;
6266    }
6267  }
6268
6269  // C++0x N2914 [namespace.udecl]p6:
6270  // A using-declaration shall not name a namespace.
6271  if (R.getAsSingle<NamespaceDecl>()) {
6272    Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace)
6273      << SS.getRange();
6274    UD->setInvalidDecl();
6275    return UD;
6276  }
6277
6278  for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
6279    if (!CheckUsingShadowDecl(UD, *I, Previous))
6280      BuildUsingShadowDecl(S, UD, *I);
6281  }
6282
6283  return UD;
6284}
6285
6286/// Additional checks for a using declaration referring to a constructor name.
6287bool Sema::CheckInheritingConstructorUsingDecl(UsingDecl *UD) {
6288  assert(!UD->isTypeName() && "expecting a constructor name");
6289
6290  const Type *SourceType = UD->getQualifier()->getAsType();
6291  assert(SourceType &&
6292         "Using decl naming constructor doesn't have type in scope spec.");
6293  CXXRecordDecl *TargetClass = cast<CXXRecordDecl>(CurContext);
6294
6295  // Check whether the named type is a direct base class.
6296  CanQualType CanonicalSourceType = SourceType->getCanonicalTypeUnqualified();
6297  CXXRecordDecl::base_class_iterator BaseIt, BaseE;
6298  for (BaseIt = TargetClass->bases_begin(), BaseE = TargetClass->bases_end();
6299       BaseIt != BaseE; ++BaseIt) {
6300    CanQualType BaseType = BaseIt->getType()->getCanonicalTypeUnqualified();
6301    if (CanonicalSourceType == BaseType)
6302      break;
6303    if (BaseIt->getType()->isDependentType())
6304      break;
6305  }
6306
6307  if (BaseIt == BaseE) {
6308    // Did not find SourceType in the bases.
6309    Diag(UD->getUsingLocation(),
6310         diag::err_using_decl_constructor_not_in_direct_base)
6311      << UD->getNameInfo().getSourceRange()
6312      << QualType(SourceType, 0) << TargetClass;
6313    return true;
6314  }
6315
6316  if (!CurContext->isDependentContext())
6317    BaseIt->setInheritConstructors();
6318
6319  return false;
6320}
6321
6322/// Checks that the given using declaration is not an invalid
6323/// redeclaration.  Note that this is checking only for the using decl
6324/// itself, not for any ill-formedness among the UsingShadowDecls.
6325bool Sema::CheckUsingDeclRedeclaration(SourceLocation UsingLoc,
6326                                       bool isTypeName,
6327                                       const CXXScopeSpec &SS,
6328                                       SourceLocation NameLoc,
6329                                       const LookupResult &Prev) {
6330  // C++03 [namespace.udecl]p8:
6331  // C++0x [namespace.udecl]p10:
6332  //   A using-declaration is a declaration and can therefore be used
6333  //   repeatedly where (and only where) multiple declarations are
6334  //   allowed.
6335  //
6336  // That's in non-member contexts.
6337  if (!CurContext->getRedeclContext()->isRecord())
6338    return false;
6339
6340  NestedNameSpecifier *Qual
6341    = static_cast<NestedNameSpecifier*>(SS.getScopeRep());
6342
6343  for (LookupResult::iterator I = Prev.begin(), E = Prev.end(); I != E; ++I) {
6344    NamedDecl *D = *I;
6345
6346    bool DTypename;
6347    NestedNameSpecifier *DQual;
6348    if (UsingDecl *UD = dyn_cast<UsingDecl>(D)) {
6349      DTypename = UD->isTypeName();
6350      DQual = UD->getQualifier();
6351    } else if (UnresolvedUsingValueDecl *UD
6352                 = dyn_cast<UnresolvedUsingValueDecl>(D)) {
6353      DTypename = false;
6354      DQual = UD->getQualifier();
6355    } else if (UnresolvedUsingTypenameDecl *UD
6356                 = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
6357      DTypename = true;
6358      DQual = UD->getQualifier();
6359    } else continue;
6360
6361    // using decls differ if one says 'typename' and the other doesn't.
6362    // FIXME: non-dependent using decls?
6363    if (isTypeName != DTypename) continue;
6364
6365    // using decls differ if they name different scopes (but note that
6366    // template instantiation can cause this check to trigger when it
6367    // didn't before instantiation).
6368    if (Context.getCanonicalNestedNameSpecifier(Qual) !=
6369        Context.getCanonicalNestedNameSpecifier(DQual))
6370      continue;
6371
6372    Diag(NameLoc, diag::err_using_decl_redeclaration) << SS.getRange();
6373    Diag(D->getLocation(), diag::note_using_decl) << 1;
6374    return true;
6375  }
6376
6377  return false;
6378}
6379
6380
6381/// Checks that the given nested-name qualifier used in a using decl
6382/// in the current context is appropriately related to the current
6383/// scope.  If an error is found, diagnoses it and returns true.
6384bool Sema::CheckUsingDeclQualifier(SourceLocation UsingLoc,
6385                                   const CXXScopeSpec &SS,
6386                                   SourceLocation NameLoc) {
6387  DeclContext *NamedContext = computeDeclContext(SS);
6388
6389  if (!CurContext->isRecord()) {
6390    // C++03 [namespace.udecl]p3:
6391    // C++0x [namespace.udecl]p8:
6392    //   A using-declaration for a class member shall be a member-declaration.
6393
6394    // If we weren't able to compute a valid scope, it must be a
6395    // dependent class scope.
6396    if (!NamedContext || NamedContext->isRecord()) {
6397      Diag(NameLoc, diag::err_using_decl_can_not_refer_to_class_member)
6398        << SS.getRange();
6399      return true;
6400    }
6401
6402    // Otherwise, everything is known to be fine.
6403    return false;
6404  }
6405
6406  // The current scope is a record.
6407
6408  // If the named context is dependent, we can't decide much.
6409  if (!NamedContext) {
6410    // FIXME: in C++0x, we can diagnose if we can prove that the
6411    // nested-name-specifier does not refer to a base class, which is
6412    // still possible in some cases.
6413
6414    // Otherwise we have to conservatively report that things might be
6415    // okay.
6416    return false;
6417  }
6418
6419  if (!NamedContext->isRecord()) {
6420    // Ideally this would point at the last name in the specifier,
6421    // but we don't have that level of source info.
6422    Diag(SS.getRange().getBegin(),
6423         diag::err_using_decl_nested_name_specifier_is_not_class)
6424      << (NestedNameSpecifier*) SS.getScopeRep() << SS.getRange();
6425    return true;
6426  }
6427
6428  if (!NamedContext->isDependentContext() &&
6429      RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), NamedContext))
6430    return true;
6431
6432  if (getLangOpts().CPlusPlus0x) {
6433    // C++0x [namespace.udecl]p3:
6434    //   In a using-declaration used as a member-declaration, the
6435    //   nested-name-specifier shall name a base class of the class
6436    //   being defined.
6437
6438    if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(
6439                                 cast<CXXRecordDecl>(NamedContext))) {
6440      if (CurContext == NamedContext) {
6441        Diag(NameLoc,
6442             diag::err_using_decl_nested_name_specifier_is_current_class)
6443          << SS.getRange();
6444        return true;
6445      }
6446
6447      Diag(SS.getRange().getBegin(),
6448           diag::err_using_decl_nested_name_specifier_is_not_base_class)
6449        << (NestedNameSpecifier*) SS.getScopeRep()
6450        << cast<CXXRecordDecl>(CurContext)
6451        << SS.getRange();
6452      return true;
6453    }
6454
6455    return false;
6456  }
6457
6458  // C++03 [namespace.udecl]p4:
6459  //   A using-declaration used as a member-declaration shall refer
6460  //   to a member of a base class of the class being defined [etc.].
6461
6462  // Salient point: SS doesn't have to name a base class as long as
6463  // lookup only finds members from base classes.  Therefore we can
6464  // diagnose here only if we can prove that that can't happen,
6465  // i.e. if the class hierarchies provably don't intersect.
6466
6467  // TODO: it would be nice if "definitely valid" results were cached
6468  // in the UsingDecl and UsingShadowDecl so that these checks didn't
6469  // need to be repeated.
6470
6471  struct UserData {
6472    llvm::SmallPtrSet<const CXXRecordDecl*, 4> Bases;
6473
6474    static bool collect(const CXXRecordDecl *Base, void *OpaqueData) {
6475      UserData *Data = reinterpret_cast<UserData*>(OpaqueData);
6476      Data->Bases.insert(Base);
6477      return true;
6478    }
6479
6480    bool hasDependentBases(const CXXRecordDecl *Class) {
6481      return !Class->forallBases(collect, this);
6482    }
6483
6484    /// Returns true if the base is dependent or is one of the
6485    /// accumulated base classes.
6486    static bool doesNotContain(const CXXRecordDecl *Base, void *OpaqueData) {
6487      UserData *Data = reinterpret_cast<UserData*>(OpaqueData);
6488      return !Data->Bases.count(Base);
6489    }
6490
6491    bool mightShareBases(const CXXRecordDecl *Class) {
6492      return Bases.count(Class) || !Class->forallBases(doesNotContain, this);
6493    }
6494  };
6495
6496  UserData Data;
6497
6498  // Returns false if we find a dependent base.
6499  if (Data.hasDependentBases(cast<CXXRecordDecl>(CurContext)))
6500    return false;
6501
6502  // Returns false if the class has a dependent base or if it or one
6503  // of its bases is present in the base set of the current context.
6504  if (Data.mightShareBases(cast<CXXRecordDecl>(NamedContext)))
6505    return false;
6506
6507  Diag(SS.getRange().getBegin(),
6508       diag::err_using_decl_nested_name_specifier_is_not_base_class)
6509    << (NestedNameSpecifier*) SS.getScopeRep()
6510    << cast<CXXRecordDecl>(CurContext)
6511    << SS.getRange();
6512
6513  return true;
6514}
6515
6516Decl *Sema::ActOnAliasDeclaration(Scope *S,
6517                                  AccessSpecifier AS,
6518                                  MultiTemplateParamsArg TemplateParamLists,
6519                                  SourceLocation UsingLoc,
6520                                  UnqualifiedId &Name,
6521                                  TypeResult Type) {
6522  // Skip up to the relevant declaration scope.
6523  while (S->getFlags() & Scope::TemplateParamScope)
6524    S = S->getParent();
6525  assert((S->getFlags() & Scope::DeclScope) &&
6526         "got alias-declaration outside of declaration scope");
6527
6528  if (Type.isInvalid())
6529    return 0;
6530
6531  bool Invalid = false;
6532  DeclarationNameInfo NameInfo = GetNameFromUnqualifiedId(Name);
6533  TypeSourceInfo *TInfo = 0;
6534  GetTypeFromParser(Type.get(), &TInfo);
6535
6536  if (DiagnoseClassNameShadow(CurContext, NameInfo))
6537    return 0;
6538
6539  if (DiagnoseUnexpandedParameterPack(Name.StartLocation, TInfo,
6540                                      UPPC_DeclarationType)) {
6541    Invalid = true;
6542    TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
6543                                             TInfo->getTypeLoc().getBeginLoc());
6544  }
6545
6546  LookupResult Previous(*this, NameInfo, LookupOrdinaryName, ForRedeclaration);
6547  LookupName(Previous, S);
6548
6549  // Warn about shadowing the name of a template parameter.
6550  if (Previous.isSingleResult() &&
6551      Previous.getFoundDecl()->isTemplateParameter()) {
6552    DiagnoseTemplateParameterShadow(Name.StartLocation,Previous.getFoundDecl());
6553    Previous.clear();
6554  }
6555
6556  assert(Name.Kind == UnqualifiedId::IK_Identifier &&
6557         "name in alias declaration must be an identifier");
6558  TypeAliasDecl *NewTD = TypeAliasDecl::Create(Context, CurContext, UsingLoc,
6559                                               Name.StartLocation,
6560                                               Name.Identifier, TInfo);
6561
6562  NewTD->setAccess(AS);
6563
6564  if (Invalid)
6565    NewTD->setInvalidDecl();
6566
6567  CheckTypedefForVariablyModifiedType(S, NewTD);
6568  Invalid |= NewTD->isInvalidDecl();
6569
6570  bool Redeclaration = false;
6571
6572  NamedDecl *NewND;
6573  if (TemplateParamLists.size()) {
6574    TypeAliasTemplateDecl *OldDecl = 0;
6575    TemplateParameterList *OldTemplateParams = 0;
6576
6577    if (TemplateParamLists.size() != 1) {
6578      Diag(UsingLoc, diag::err_alias_template_extra_headers)
6579        << SourceRange(TemplateParamLists.get()[1]->getTemplateLoc(),
6580         TemplateParamLists.get()[TemplateParamLists.size()-1]->getRAngleLoc());
6581    }
6582    TemplateParameterList *TemplateParams = TemplateParamLists.get()[0];
6583
6584    // Only consider previous declarations in the same scope.
6585    FilterLookupForScope(Previous, CurContext, S, /*ConsiderLinkage*/false,
6586                         /*ExplicitInstantiationOrSpecialization*/false);
6587    if (!Previous.empty()) {
6588      Redeclaration = true;
6589
6590      OldDecl = Previous.getAsSingle<TypeAliasTemplateDecl>();
6591      if (!OldDecl && !Invalid) {
6592        Diag(UsingLoc, diag::err_redefinition_different_kind)
6593          << Name.Identifier;
6594
6595        NamedDecl *OldD = Previous.getRepresentativeDecl();
6596        if (OldD->getLocation().isValid())
6597          Diag(OldD->getLocation(), diag::note_previous_definition);
6598
6599        Invalid = true;
6600      }
6601
6602      if (!Invalid && OldDecl && !OldDecl->isInvalidDecl()) {
6603        if (TemplateParameterListsAreEqual(TemplateParams,
6604                                           OldDecl->getTemplateParameters(),
6605                                           /*Complain=*/true,
6606                                           TPL_TemplateMatch))
6607          OldTemplateParams = OldDecl->getTemplateParameters();
6608        else
6609          Invalid = true;
6610
6611        TypeAliasDecl *OldTD = OldDecl->getTemplatedDecl();
6612        if (!Invalid &&
6613            !Context.hasSameType(OldTD->getUnderlyingType(),
6614                                 NewTD->getUnderlyingType())) {
6615          // FIXME: The C++0x standard does not clearly say this is ill-formed,
6616          // but we can't reasonably accept it.
6617          Diag(NewTD->getLocation(), diag::err_redefinition_different_typedef)
6618            << 2 << NewTD->getUnderlyingType() << OldTD->getUnderlyingType();
6619          if (OldTD->getLocation().isValid())
6620            Diag(OldTD->getLocation(), diag::note_previous_definition);
6621          Invalid = true;
6622        }
6623      }
6624    }
6625
6626    // Merge any previous default template arguments into our parameters,
6627    // and check the parameter list.
6628    if (CheckTemplateParameterList(TemplateParams, OldTemplateParams,
6629                                   TPC_TypeAliasTemplate))
6630      return 0;
6631
6632    TypeAliasTemplateDecl *NewDecl =
6633      TypeAliasTemplateDecl::Create(Context, CurContext, UsingLoc,
6634                                    Name.Identifier, TemplateParams,
6635                                    NewTD);
6636
6637    NewDecl->setAccess(AS);
6638
6639    if (Invalid)
6640      NewDecl->setInvalidDecl();
6641    else if (OldDecl)
6642      NewDecl->setPreviousDeclaration(OldDecl);
6643
6644    NewND = NewDecl;
6645  } else {
6646    ActOnTypedefNameDecl(S, CurContext, NewTD, Previous, Redeclaration);
6647    NewND = NewTD;
6648  }
6649
6650  if (!Redeclaration)
6651    PushOnScopeChains(NewND, S);
6652
6653  ActOnDocumentableDecl(NewND);
6654  return NewND;
6655}
6656
6657Decl *Sema::ActOnNamespaceAliasDef(Scope *S,
6658                                             SourceLocation NamespaceLoc,
6659                                             SourceLocation AliasLoc,
6660                                             IdentifierInfo *Alias,
6661                                             CXXScopeSpec &SS,
6662                                             SourceLocation IdentLoc,
6663                                             IdentifierInfo *Ident) {
6664
6665  // Lookup the namespace name.
6666  LookupResult R(*this, Ident, IdentLoc, LookupNamespaceName);
6667  LookupParsedName(R, S, &SS);
6668
6669  // Check if we have a previous declaration with the same name.
6670  NamedDecl *PrevDecl
6671    = LookupSingleName(S, Alias, AliasLoc, LookupOrdinaryName,
6672                       ForRedeclaration);
6673  if (PrevDecl && !isDeclInScope(PrevDecl, CurContext, S))
6674    PrevDecl = 0;
6675
6676  if (PrevDecl) {
6677    if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) {
6678      // We already have an alias with the same name that points to the same
6679      // namespace, so don't create a new one.
6680      // FIXME: At some point, we'll want to create the (redundant)
6681      // declaration to maintain better source information.
6682      if (!R.isAmbiguous() && !R.empty() &&
6683          AD->getNamespace()->Equals(getNamespaceDecl(R.getFoundDecl())))
6684        return 0;
6685    }
6686
6687    unsigned DiagID = isa<NamespaceDecl>(PrevDecl) ? diag::err_redefinition :
6688      diag::err_redefinition_different_kind;
6689    Diag(AliasLoc, DiagID) << Alias;
6690    Diag(PrevDecl->getLocation(), diag::note_previous_definition);
6691    return 0;
6692  }
6693
6694  if (R.isAmbiguous())
6695    return 0;
6696
6697  if (R.empty()) {
6698    if (!TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, Ident)) {
6699      Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
6700      return 0;
6701    }
6702  }
6703
6704  NamespaceAliasDecl *AliasDecl =
6705    NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc,
6706                               Alias, SS.getWithLocInContext(Context),
6707                               IdentLoc, R.getFoundDecl());
6708
6709  PushOnScopeChains(AliasDecl, S);
6710  return AliasDecl;
6711}
6712
6713namespace {
6714  /// \brief Scoped object used to handle the state changes required in Sema
6715  /// to implicitly define the body of a C++ member function;
6716  class ImplicitlyDefinedFunctionScope {
6717    Sema &S;
6718    Sema::ContextRAII SavedContext;
6719
6720  public:
6721    ImplicitlyDefinedFunctionScope(Sema &S, CXXMethodDecl *Method)
6722      : S(S), SavedContext(S, Method)
6723    {
6724      S.PushFunctionScope();
6725      S.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
6726    }
6727
6728    ~ImplicitlyDefinedFunctionScope() {
6729      S.PopExpressionEvaluationContext();
6730      S.PopFunctionScopeInfo();
6731    }
6732  };
6733}
6734
6735Sema::ImplicitExceptionSpecification
6736Sema::ComputeDefaultedDefaultCtorExceptionSpec(SourceLocation Loc,
6737                                               CXXMethodDecl *MD) {
6738  CXXRecordDecl *ClassDecl = MD->getParent();
6739
6740  // C++ [except.spec]p14:
6741  //   An implicitly declared special member function (Clause 12) shall have an
6742  //   exception-specification. [...]
6743  ImplicitExceptionSpecification ExceptSpec(*this);
6744  if (ClassDecl->isInvalidDecl())
6745    return ExceptSpec;
6746
6747  // Direct base-class constructors.
6748  for (CXXRecordDecl::base_class_iterator B = ClassDecl->bases_begin(),
6749                                       BEnd = ClassDecl->bases_end();
6750       B != BEnd; ++B) {
6751    if (B->isVirtual()) // Handled below.
6752      continue;
6753
6754    if (const RecordType *BaseType = B->getType()->getAs<RecordType>()) {
6755      CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
6756      CXXConstructorDecl *Constructor = LookupDefaultConstructor(BaseClassDecl);
6757      // If this is a deleted function, add it anyway. This might be conformant
6758      // with the standard. This might not. I'm not sure. It might not matter.
6759      if (Constructor)
6760        ExceptSpec.CalledDecl(B->getLocStart(), Constructor);
6761    }
6762  }
6763
6764  // Virtual base-class constructors.
6765  for (CXXRecordDecl::base_class_iterator B = ClassDecl->vbases_begin(),
6766                                       BEnd = ClassDecl->vbases_end();
6767       B != BEnd; ++B) {
6768    if (const RecordType *BaseType = B->getType()->getAs<RecordType>()) {
6769      CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
6770      CXXConstructorDecl *Constructor = LookupDefaultConstructor(BaseClassDecl);
6771      // If this is a deleted function, add it anyway. This might be conformant
6772      // with the standard. This might not. I'm not sure. It might not matter.
6773      if (Constructor)
6774        ExceptSpec.CalledDecl(B->getLocStart(), Constructor);
6775    }
6776  }
6777
6778  // Field constructors.
6779  for (RecordDecl::field_iterator F = ClassDecl->field_begin(),
6780                               FEnd = ClassDecl->field_end();
6781       F != FEnd; ++F) {
6782    if (F->hasInClassInitializer()) {
6783      if (Expr *E = F->getInClassInitializer())
6784        ExceptSpec.CalledExpr(E);
6785      else if (!F->isInvalidDecl())
6786        // DR1351:
6787        //   If the brace-or-equal-initializer of a non-static data member
6788        //   invokes a defaulted default constructor of its class or of an
6789        //   enclosing class in a potentially evaluated subexpression, the
6790        //   program is ill-formed.
6791        //
6792        // This resolution is unworkable: the exception specification of the
6793        // default constructor can be needed in an unevaluated context, in
6794        // particular, in the operand of a noexcept-expression, and we can be
6795        // unable to compute an exception specification for an enclosed class.
6796        //
6797        // We do not allow an in-class initializer to require the evaluation
6798        // of the exception specification for any in-class initializer whose
6799        // definition is not lexically complete.
6800        Diag(Loc, diag::err_in_class_initializer_references_def_ctor) << MD;
6801    } else if (const RecordType *RecordTy
6802              = Context.getBaseElementType(F->getType())->getAs<RecordType>()) {
6803      CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
6804      CXXConstructorDecl *Constructor = LookupDefaultConstructor(FieldRecDecl);
6805      // If this is a deleted function, add it anyway. This might be conformant
6806      // with the standard. This might not. I'm not sure. It might not matter.
6807      // In particular, the problem is that this function never gets called. It
6808      // might just be ill-formed because this function attempts to refer to
6809      // a deleted function here.
6810      if (Constructor)
6811        ExceptSpec.CalledDecl(F->getLocation(), Constructor);
6812    }
6813  }
6814
6815  return ExceptSpec;
6816}
6817
6818CXXConstructorDecl *Sema::DeclareImplicitDefaultConstructor(
6819                                                     CXXRecordDecl *ClassDecl) {
6820  // C++ [class.ctor]p5:
6821  //   A default constructor for a class X is a constructor of class X
6822  //   that can be called without an argument. If there is no
6823  //   user-declared constructor for class X, a default constructor is
6824  //   implicitly declared. An implicitly-declared default constructor
6825  //   is an inline public member of its class.
6826  assert(!ClassDecl->hasUserDeclaredConstructor() &&
6827         "Should not build implicit default constructor!");
6828
6829  bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
6830                                                     CXXDefaultConstructor,
6831                                                     false);
6832
6833  // Create the actual constructor declaration.
6834  CanQualType ClassType
6835    = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
6836  SourceLocation ClassLoc = ClassDecl->getLocation();
6837  DeclarationName Name
6838    = Context.DeclarationNames.getCXXConstructorName(ClassType);
6839  DeclarationNameInfo NameInfo(Name, ClassLoc);
6840  CXXConstructorDecl *DefaultCon = CXXConstructorDecl::Create(
6841      Context, ClassDecl, ClassLoc, NameInfo, /*Type*/QualType(), /*TInfo=*/0,
6842      /*isExplicit=*/false, /*isInline=*/true, /*isImplicitlyDeclared=*/true,
6843      Constexpr);
6844  DefaultCon->setAccess(AS_public);
6845  DefaultCon->setDefaulted();
6846  DefaultCon->setImplicit();
6847  DefaultCon->setTrivial(ClassDecl->hasTrivialDefaultConstructor());
6848
6849  // Build an exception specification pointing back at this constructor.
6850  FunctionProtoType::ExtProtoInfo EPI;
6851  EPI.ExceptionSpecType = EST_Unevaluated;
6852  EPI.ExceptionSpecDecl = DefaultCon;
6853  DefaultCon->setType(Context.getFunctionType(Context.VoidTy, 0, 0, EPI));
6854
6855  // Note that we have declared this constructor.
6856  ++ASTContext::NumImplicitDefaultConstructorsDeclared;
6857
6858  if (Scope *S = getScopeForContext(ClassDecl))
6859    PushOnScopeChains(DefaultCon, S, false);
6860  ClassDecl->addDecl(DefaultCon);
6861
6862  if (ShouldDeleteSpecialMember(DefaultCon, CXXDefaultConstructor))
6863    DefaultCon->setDeletedAsWritten();
6864
6865  return DefaultCon;
6866}
6867
6868void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
6869                                            CXXConstructorDecl *Constructor) {
6870  assert((Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&
6871          !Constructor->doesThisDeclarationHaveABody() &&
6872          !Constructor->isDeleted()) &&
6873    "DefineImplicitDefaultConstructor - call it for implicit default ctor");
6874
6875  CXXRecordDecl *ClassDecl = Constructor->getParent();
6876  assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor");
6877
6878  ImplicitlyDefinedFunctionScope Scope(*this, Constructor);
6879  DiagnosticErrorTrap Trap(Diags);
6880  if (SetCtorInitializers(Constructor, 0, 0, /*AnyErrors=*/false) ||
6881      Trap.hasErrorOccurred()) {
6882    Diag(CurrentLocation, diag::note_member_synthesized_at)
6883      << CXXDefaultConstructor << Context.getTagDeclType(ClassDecl);
6884    Constructor->setInvalidDecl();
6885    return;
6886  }
6887
6888  SourceLocation Loc = Constructor->getLocation();
6889  Constructor->setBody(new (Context) CompoundStmt(Loc));
6890
6891  Constructor->setUsed();
6892  MarkVTableUsed(CurrentLocation, ClassDecl);
6893
6894  if (ASTMutationListener *L = getASTMutationListener()) {
6895    L->CompletedImplicitDefinition(Constructor);
6896  }
6897}
6898
6899void Sema::ActOnFinishDelayedMemberInitializers(Decl *D) {
6900  if (!D) return;
6901  AdjustDeclIfTemplate(D);
6902
6903  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(D);
6904
6905  if (!ClassDecl->isDependentType())
6906    CheckExplicitlyDefaultedMethods(ClassDecl);
6907}
6908
6909void Sema::DeclareInheritedConstructors(CXXRecordDecl *ClassDecl) {
6910  // We start with an initial pass over the base classes to collect those that
6911  // inherit constructors from. If there are none, we can forgo all further
6912  // processing.
6913  typedef SmallVector<const RecordType *, 4> BasesVector;
6914  BasesVector BasesToInheritFrom;
6915  for (CXXRecordDecl::base_class_iterator BaseIt = ClassDecl->bases_begin(),
6916                                          BaseE = ClassDecl->bases_end();
6917         BaseIt != BaseE; ++BaseIt) {
6918    if (BaseIt->getInheritConstructors()) {
6919      QualType Base = BaseIt->getType();
6920      if (Base->isDependentType()) {
6921        // If we inherit constructors from anything that is dependent, just
6922        // abort processing altogether. We'll get another chance for the
6923        // instantiations.
6924        return;
6925      }
6926      BasesToInheritFrom.push_back(Base->castAs<RecordType>());
6927    }
6928  }
6929  if (BasesToInheritFrom.empty())
6930    return;
6931
6932  // Now collect the constructors that we already have in the current class.
6933  // Those take precedence over inherited constructors.
6934  // C++0x [class.inhctor]p3: [...] a constructor is implicitly declared [...]
6935  //   unless there is a user-declared constructor with the same signature in
6936  //   the class where the using-declaration appears.
6937  llvm::SmallSet<const Type *, 8> ExistingConstructors;
6938  for (CXXRecordDecl::ctor_iterator CtorIt = ClassDecl->ctor_begin(),
6939                                    CtorE = ClassDecl->ctor_end();
6940       CtorIt != CtorE; ++CtorIt) {
6941    ExistingConstructors.insert(
6942        Context.getCanonicalType(CtorIt->getType()).getTypePtr());
6943  }
6944
6945  DeclarationName CreatedCtorName =
6946      Context.DeclarationNames.getCXXConstructorName(
6947          ClassDecl->getTypeForDecl()->getCanonicalTypeUnqualified());
6948
6949  // Now comes the true work.
6950  // First, we keep a map from constructor types to the base that introduced
6951  // them. Needed for finding conflicting constructors. We also keep the
6952  // actually inserted declarations in there, for pretty diagnostics.
6953  typedef std::pair<CanQualType, CXXConstructorDecl *> ConstructorInfo;
6954  typedef llvm::DenseMap<const Type *, ConstructorInfo> ConstructorToSourceMap;
6955  ConstructorToSourceMap InheritedConstructors;
6956  for (BasesVector::iterator BaseIt = BasesToInheritFrom.begin(),
6957                             BaseE = BasesToInheritFrom.end();
6958       BaseIt != BaseE; ++BaseIt) {
6959    const RecordType *Base = *BaseIt;
6960    CanQualType CanonicalBase = Base->getCanonicalTypeUnqualified();
6961    CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(Base->getDecl());
6962    for (CXXRecordDecl::ctor_iterator CtorIt = BaseDecl->ctor_begin(),
6963                                      CtorE = BaseDecl->ctor_end();
6964         CtorIt != CtorE; ++CtorIt) {
6965      // Find the using declaration for inheriting this base's constructors.
6966      // FIXME: Don't perform name lookup just to obtain a source location!
6967      DeclarationName Name =
6968          Context.DeclarationNames.getCXXConstructorName(CanonicalBase);
6969      LookupResult Result(*this, Name, SourceLocation(), LookupUsingDeclName);
6970      LookupQualifiedName(Result, CurContext);
6971      UsingDecl *UD = Result.getAsSingle<UsingDecl>();
6972      SourceLocation UsingLoc = UD ? UD->getLocation() :
6973                                     ClassDecl->getLocation();
6974
6975      // C++0x [class.inhctor]p1: The candidate set of inherited constructors
6976      //   from the class X named in the using-declaration consists of actual
6977      //   constructors and notional constructors that result from the
6978      //   transformation of defaulted parameters as follows:
6979      //   - all non-template default constructors of X, and
6980      //   - for each non-template constructor of X that has at least one
6981      //     parameter with a default argument, the set of constructors that
6982      //     results from omitting any ellipsis parameter specification and
6983      //     successively omitting parameters with a default argument from the
6984      //     end of the parameter-type-list.
6985      CXXConstructorDecl *BaseCtor = *CtorIt;
6986      bool CanBeCopyOrMove = BaseCtor->isCopyOrMoveConstructor();
6987      const FunctionProtoType *BaseCtorType =
6988          BaseCtor->getType()->getAs<FunctionProtoType>();
6989
6990      for (unsigned params = BaseCtor->getMinRequiredArguments(),
6991                    maxParams = BaseCtor->getNumParams();
6992           params <= maxParams; ++params) {
6993        // Skip default constructors. They're never inherited.
6994        if (params == 0)
6995          continue;
6996        // Skip copy and move constructors for the same reason.
6997        if (CanBeCopyOrMove && params == 1)
6998          continue;
6999
7000        // Build up a function type for this particular constructor.
7001        // FIXME: The working paper does not consider that the exception spec
7002        // for the inheriting constructor might be larger than that of the
7003        // source. This code doesn't yet, either. When it does, this code will
7004        // need to be delayed until after exception specifications and in-class
7005        // member initializers are attached.
7006        const Type *NewCtorType;
7007        if (params == maxParams)
7008          NewCtorType = BaseCtorType;
7009        else {
7010          SmallVector<QualType, 16> Args;
7011          for (unsigned i = 0; i < params; ++i) {
7012            Args.push_back(BaseCtorType->getArgType(i));
7013          }
7014          FunctionProtoType::ExtProtoInfo ExtInfo =
7015              BaseCtorType->getExtProtoInfo();
7016          ExtInfo.Variadic = false;
7017          NewCtorType = Context.getFunctionType(BaseCtorType->getResultType(),
7018                                                Args.data(), params, ExtInfo)
7019                       .getTypePtr();
7020        }
7021        const Type *CanonicalNewCtorType =
7022            Context.getCanonicalType(NewCtorType);
7023
7024        // Now that we have the type, first check if the class already has a
7025        // constructor with this signature.
7026        if (ExistingConstructors.count(CanonicalNewCtorType))
7027          continue;
7028
7029        // Then we check if we have already declared an inherited constructor
7030        // with this signature.
7031        std::pair<ConstructorToSourceMap::iterator, bool> result =
7032            InheritedConstructors.insert(std::make_pair(
7033                CanonicalNewCtorType,
7034                std::make_pair(CanonicalBase, (CXXConstructorDecl*)0)));
7035        if (!result.second) {
7036          // Already in the map. If it came from a different class, that's an
7037          // error. Not if it's from the same.
7038          CanQualType PreviousBase = result.first->second.first;
7039          if (CanonicalBase != PreviousBase) {
7040            const CXXConstructorDecl *PrevCtor = result.first->second.second;
7041            const CXXConstructorDecl *PrevBaseCtor =
7042                PrevCtor->getInheritedConstructor();
7043            assert(PrevBaseCtor && "Conflicting constructor was not inherited");
7044
7045            Diag(UsingLoc, diag::err_using_decl_constructor_conflict);
7046            Diag(BaseCtor->getLocation(),
7047                 diag::note_using_decl_constructor_conflict_current_ctor);
7048            Diag(PrevBaseCtor->getLocation(),
7049                 diag::note_using_decl_constructor_conflict_previous_ctor);
7050            Diag(PrevCtor->getLocation(),
7051                 diag::note_using_decl_constructor_conflict_previous_using);
7052          }
7053          continue;
7054        }
7055
7056        // OK, we're there, now add the constructor.
7057        // C++0x [class.inhctor]p8: [...] that would be performed by a
7058        //   user-written inline constructor [...]
7059        DeclarationNameInfo DNI(CreatedCtorName, UsingLoc);
7060        CXXConstructorDecl *NewCtor = CXXConstructorDecl::Create(
7061            Context, ClassDecl, UsingLoc, DNI, QualType(NewCtorType, 0),
7062            /*TInfo=*/0, BaseCtor->isExplicit(), /*Inline=*/true,
7063            /*ImplicitlyDeclared=*/true,
7064            // FIXME: Due to a defect in the standard, we treat inherited
7065            // constructors as constexpr even if that makes them ill-formed.
7066            /*Constexpr=*/BaseCtor->isConstexpr());
7067        NewCtor->setAccess(BaseCtor->getAccess());
7068
7069        // Build up the parameter decls and add them.
7070        SmallVector<ParmVarDecl *, 16> ParamDecls;
7071        for (unsigned i = 0; i < params; ++i) {
7072          ParamDecls.push_back(ParmVarDecl::Create(Context, NewCtor,
7073                                                   UsingLoc, UsingLoc,
7074                                                   /*IdentifierInfo=*/0,
7075                                                   BaseCtorType->getArgType(i),
7076                                                   /*TInfo=*/0, SC_None,
7077                                                   SC_None, /*DefaultArg=*/0));
7078        }
7079        NewCtor->setParams(ParamDecls);
7080        NewCtor->setInheritedConstructor(BaseCtor);
7081
7082        ClassDecl->addDecl(NewCtor);
7083        result.first->second.second = NewCtor;
7084      }
7085    }
7086  }
7087}
7088
7089Sema::ImplicitExceptionSpecification
7090Sema::ComputeDefaultedDtorExceptionSpec(CXXMethodDecl *MD) {
7091  CXXRecordDecl *ClassDecl = MD->getParent();
7092
7093  // C++ [except.spec]p14:
7094  //   An implicitly declared special member function (Clause 12) shall have
7095  //   an exception-specification.
7096  ImplicitExceptionSpecification ExceptSpec(*this);
7097  if (ClassDecl->isInvalidDecl())
7098    return ExceptSpec;
7099
7100  // Direct base-class destructors.
7101  for (CXXRecordDecl::base_class_iterator B = ClassDecl->bases_begin(),
7102                                       BEnd = ClassDecl->bases_end();
7103       B != BEnd; ++B) {
7104    if (B->isVirtual()) // Handled below.
7105      continue;
7106
7107    if (const RecordType *BaseType = B->getType()->getAs<RecordType>())
7108      ExceptSpec.CalledDecl(B->getLocStart(),
7109                   LookupDestructor(cast<CXXRecordDecl>(BaseType->getDecl())));
7110  }
7111
7112  // Virtual base-class destructors.
7113  for (CXXRecordDecl::base_class_iterator B = ClassDecl->vbases_begin(),
7114                                       BEnd = ClassDecl->vbases_end();
7115       B != BEnd; ++B) {
7116    if (const RecordType *BaseType = B->getType()->getAs<RecordType>())
7117      ExceptSpec.CalledDecl(B->getLocStart(),
7118                  LookupDestructor(cast<CXXRecordDecl>(BaseType->getDecl())));
7119  }
7120
7121  // Field destructors.
7122  for (RecordDecl::field_iterator F = ClassDecl->field_begin(),
7123                               FEnd = ClassDecl->field_end();
7124       F != FEnd; ++F) {
7125    if (const RecordType *RecordTy
7126        = Context.getBaseElementType(F->getType())->getAs<RecordType>())
7127      ExceptSpec.CalledDecl(F->getLocation(),
7128                  LookupDestructor(cast<CXXRecordDecl>(RecordTy->getDecl())));
7129  }
7130
7131  return ExceptSpec;
7132}
7133
7134CXXDestructorDecl *Sema::DeclareImplicitDestructor(CXXRecordDecl *ClassDecl) {
7135  // C++ [class.dtor]p2:
7136  //   If a class has no user-declared destructor, a destructor is
7137  //   declared implicitly. An implicitly-declared destructor is an
7138  //   inline public member of its class.
7139
7140  // Create the actual destructor declaration.
7141  CanQualType ClassType
7142    = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
7143  SourceLocation ClassLoc = ClassDecl->getLocation();
7144  DeclarationName Name
7145    = Context.DeclarationNames.getCXXDestructorName(ClassType);
7146  DeclarationNameInfo NameInfo(Name, ClassLoc);
7147  CXXDestructorDecl *Destructor
7148      = CXXDestructorDecl::Create(Context, ClassDecl, ClassLoc, NameInfo,
7149                                  QualType(), 0, /*isInline=*/true,
7150                                  /*isImplicitlyDeclared=*/true);
7151  Destructor->setAccess(AS_public);
7152  Destructor->setDefaulted();
7153  Destructor->setImplicit();
7154  Destructor->setTrivial(ClassDecl->hasTrivialDestructor());
7155
7156  // Build an exception specification pointing back at this destructor.
7157  FunctionProtoType::ExtProtoInfo EPI;
7158  EPI.ExceptionSpecType = EST_Unevaluated;
7159  EPI.ExceptionSpecDecl = Destructor;
7160  Destructor->setType(Context.getFunctionType(Context.VoidTy, 0, 0, EPI));
7161
7162  // Note that we have declared this destructor.
7163  ++ASTContext::NumImplicitDestructorsDeclared;
7164
7165  // Introduce this destructor into its scope.
7166  if (Scope *S = getScopeForContext(ClassDecl))
7167    PushOnScopeChains(Destructor, S, false);
7168  ClassDecl->addDecl(Destructor);
7169
7170  AddOverriddenMethods(ClassDecl, Destructor);
7171
7172  if (ShouldDeleteSpecialMember(Destructor, CXXDestructor))
7173    Destructor->setDeletedAsWritten();
7174
7175  return Destructor;
7176}
7177
7178void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation,
7179                                    CXXDestructorDecl *Destructor) {
7180  assert((Destructor->isDefaulted() &&
7181          !Destructor->doesThisDeclarationHaveABody() &&
7182          !Destructor->isDeleted()) &&
7183         "DefineImplicitDestructor - call it for implicit default dtor");
7184  CXXRecordDecl *ClassDecl = Destructor->getParent();
7185  assert(ClassDecl && "DefineImplicitDestructor - invalid destructor");
7186
7187  if (Destructor->isInvalidDecl())
7188    return;
7189
7190  ImplicitlyDefinedFunctionScope Scope(*this, Destructor);
7191
7192  DiagnosticErrorTrap Trap(Diags);
7193  MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(),
7194                                         Destructor->getParent());
7195
7196  if (CheckDestructor(Destructor) || Trap.hasErrorOccurred()) {
7197    Diag(CurrentLocation, diag::note_member_synthesized_at)
7198      << CXXDestructor << Context.getTagDeclType(ClassDecl);
7199
7200    Destructor->setInvalidDecl();
7201    return;
7202  }
7203
7204  SourceLocation Loc = Destructor->getLocation();
7205  Destructor->setBody(new (Context) CompoundStmt(Loc));
7206  Destructor->setImplicitlyDefined(true);
7207  Destructor->setUsed();
7208  MarkVTableUsed(CurrentLocation, ClassDecl);
7209
7210  if (ASTMutationListener *L = getASTMutationListener()) {
7211    L->CompletedImplicitDefinition(Destructor);
7212  }
7213}
7214
7215/// \brief Perform any semantic analysis which needs to be delayed until all
7216/// pending class member declarations have been parsed.
7217void Sema::ActOnFinishCXXMemberDecls() {
7218  // Perform any deferred checking of exception specifications for virtual
7219  // destructors.
7220  for (unsigned i = 0, e = DelayedDestructorExceptionSpecChecks.size();
7221       i != e; ++i) {
7222    const CXXDestructorDecl *Dtor =
7223        DelayedDestructorExceptionSpecChecks[i].first;
7224    assert(!Dtor->getParent()->isDependentType() &&
7225           "Should not ever add destructors of templates into the list.");
7226    CheckOverridingFunctionExceptionSpec(Dtor,
7227        DelayedDestructorExceptionSpecChecks[i].second);
7228  }
7229  DelayedDestructorExceptionSpecChecks.clear();
7230}
7231
7232void Sema::AdjustDestructorExceptionSpec(CXXRecordDecl *ClassDecl,
7233                                         CXXDestructorDecl *Destructor) {
7234  assert(getLangOpts().CPlusPlus0x &&
7235         "adjusting dtor exception specs was introduced in c++11");
7236
7237  // C++11 [class.dtor]p3:
7238  //   A declaration of a destructor that does not have an exception-
7239  //   specification is implicitly considered to have the same exception-
7240  //   specification as an implicit declaration.
7241  const FunctionProtoType *DtorType = Destructor->getType()->
7242                                        getAs<FunctionProtoType>();
7243  if (DtorType->hasExceptionSpec())
7244    return;
7245
7246  // Replace the destructor's type, building off the existing one. Fortunately,
7247  // the only thing of interest in the destructor type is its extended info.
7248  // The return and arguments are fixed.
7249  FunctionProtoType::ExtProtoInfo EPI = DtorType->getExtProtoInfo();
7250  EPI.ExceptionSpecType = EST_Unevaluated;
7251  EPI.ExceptionSpecDecl = Destructor;
7252  Destructor->setType(Context.getFunctionType(Context.VoidTy, 0, 0, EPI));
7253
7254  // FIXME: If the destructor has a body that could throw, and the newly created
7255  // spec doesn't allow exceptions, we should emit a warning, because this
7256  // change in behavior can break conforming C++03 programs at runtime.
7257  // However, we don't have a body or an exception specification yet, so it
7258  // needs to be done somewhere else.
7259}
7260
7261/// \brief Builds a statement that copies/moves the given entity from \p From to
7262/// \c To.
7263///
7264/// This routine is used to copy/move the members of a class with an
7265/// implicitly-declared copy/move assignment operator. When the entities being
7266/// copied are arrays, this routine builds for loops to copy them.
7267///
7268/// \param S The Sema object used for type-checking.
7269///
7270/// \param Loc The location where the implicit copy/move is being generated.
7271///
7272/// \param T The type of the expressions being copied/moved. Both expressions
7273/// must have this type.
7274///
7275/// \param To The expression we are copying/moving to.
7276///
7277/// \param From The expression we are copying/moving from.
7278///
7279/// \param CopyingBaseSubobject Whether we're copying/moving a base subobject.
7280/// Otherwise, it's a non-static member subobject.
7281///
7282/// \param Copying Whether we're copying or moving.
7283///
7284/// \param Depth Internal parameter recording the depth of the recursion.
7285///
7286/// \returns A statement or a loop that copies the expressions.
7287static StmtResult
7288BuildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T,
7289                      Expr *To, Expr *From,
7290                      bool CopyingBaseSubobject, bool Copying,
7291                      unsigned Depth = 0) {
7292  // C++0x [class.copy]p28:
7293  //   Each subobject is assigned in the manner appropriate to its type:
7294  //
7295  //     - if the subobject is of class type, as if by a call to operator= with
7296  //       the subobject as the object expression and the corresponding
7297  //       subobject of x as a single function argument (as if by explicit
7298  //       qualification; that is, ignoring any possible virtual overriding
7299  //       functions in more derived classes);
7300  if (const RecordType *RecordTy = T->getAs<RecordType>()) {
7301    CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
7302
7303    // Look for operator=.
7304    DeclarationName Name
7305      = S.Context.DeclarationNames.getCXXOperatorName(OO_Equal);
7306    LookupResult OpLookup(S, Name, Loc, Sema::LookupOrdinaryName);
7307    S.LookupQualifiedName(OpLookup, ClassDecl, false);
7308
7309    // Filter out any result that isn't a copy/move-assignment operator.
7310    LookupResult::Filter F = OpLookup.makeFilter();
7311    while (F.hasNext()) {
7312      NamedDecl *D = F.next();
7313      if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
7314        if (Method->isCopyAssignmentOperator() ||
7315            (!Copying && Method->isMoveAssignmentOperator()))
7316          continue;
7317
7318      F.erase();
7319    }
7320    F.done();
7321
7322    // Suppress the protected check (C++ [class.protected]) for each of the
7323    // assignment operators we found. This strange dance is required when
7324    // we're assigning via a base classes's copy-assignment operator. To
7325    // ensure that we're getting the right base class subobject (without
7326    // ambiguities), we need to cast "this" to that subobject type; to
7327    // ensure that we don't go through the virtual call mechanism, we need
7328    // to qualify the operator= name with the base class (see below). However,
7329    // this means that if the base class has a protected copy assignment
7330    // operator, the protected member access check will fail. So, we
7331    // rewrite "protected" access to "public" access in this case, since we
7332    // know by construction that we're calling from a derived class.
7333    if (CopyingBaseSubobject) {
7334      for (LookupResult::iterator L = OpLookup.begin(), LEnd = OpLookup.end();
7335           L != LEnd; ++L) {
7336        if (L.getAccess() == AS_protected)
7337          L.setAccess(AS_public);
7338      }
7339    }
7340
7341    // Create the nested-name-specifier that will be used to qualify the
7342    // reference to operator=; this is required to suppress the virtual
7343    // call mechanism.
7344    CXXScopeSpec SS;
7345    const Type *CanonicalT = S.Context.getCanonicalType(T.getTypePtr());
7346    SS.MakeTrivial(S.Context,
7347                   NestedNameSpecifier::Create(S.Context, 0, false,
7348                                               CanonicalT),
7349                   Loc);
7350
7351    // Create the reference to operator=.
7352    ExprResult OpEqualRef
7353      = S.BuildMemberReferenceExpr(To, T, Loc, /*isArrow=*/false, SS,
7354                                   /*TemplateKWLoc=*/SourceLocation(),
7355                                   /*FirstQualifierInScope=*/0,
7356                                   OpLookup,
7357                                   /*TemplateArgs=*/0,
7358                                   /*SuppressQualifierCheck=*/true);
7359    if (OpEqualRef.isInvalid())
7360      return StmtError();
7361
7362    // Build the call to the assignment operator.
7363
7364    ExprResult Call = S.BuildCallToMemberFunction(/*Scope=*/0,
7365                                                  OpEqualRef.takeAs<Expr>(),
7366                                                  Loc, &From, 1, Loc);
7367    if (Call.isInvalid())
7368      return StmtError();
7369
7370    return S.Owned(Call.takeAs<Stmt>());
7371  }
7372
7373  //     - if the subobject is of scalar type, the built-in assignment
7374  //       operator is used.
7375  const ConstantArrayType *ArrayTy = S.Context.getAsConstantArrayType(T);
7376  if (!ArrayTy) {
7377    ExprResult Assignment = S.CreateBuiltinBinOp(Loc, BO_Assign, To, From);
7378    if (Assignment.isInvalid())
7379      return StmtError();
7380
7381    return S.Owned(Assignment.takeAs<Stmt>());
7382  }
7383
7384  //     - if the subobject is an array, each element is assigned, in the
7385  //       manner appropriate to the element type;
7386
7387  // Construct a loop over the array bounds, e.g.,
7388  //
7389  //   for (__SIZE_TYPE__ i0 = 0; i0 != array-size; ++i0)
7390  //
7391  // that will copy each of the array elements.
7392  QualType SizeType = S.Context.getSizeType();
7393
7394  // Create the iteration variable.
7395  IdentifierInfo *IterationVarName = 0;
7396  {
7397    SmallString<8> Str;
7398    llvm::raw_svector_ostream OS(Str);
7399    OS << "__i" << Depth;
7400    IterationVarName = &S.Context.Idents.get(OS.str());
7401  }
7402  VarDecl *IterationVar = VarDecl::Create(S.Context, S.CurContext, Loc, Loc,
7403                                          IterationVarName, SizeType,
7404                            S.Context.getTrivialTypeSourceInfo(SizeType, Loc),
7405                                          SC_None, SC_None);
7406
7407  // Initialize the iteration variable to zero.
7408  llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0);
7409  IterationVar->setInit(IntegerLiteral::Create(S.Context, Zero, SizeType, Loc));
7410
7411  // Create a reference to the iteration variable; we'll use this several
7412  // times throughout.
7413  Expr *IterationVarRef
7414    = S.BuildDeclRefExpr(IterationVar, SizeType, VK_LValue, Loc).take();
7415  assert(IterationVarRef && "Reference to invented variable cannot fail!");
7416  Expr *IterationVarRefRVal = S.DefaultLvalueConversion(IterationVarRef).take();
7417  assert(IterationVarRefRVal && "Conversion of invented variable cannot fail!");
7418
7419  // Create the DeclStmt that holds the iteration variable.
7420  Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(IterationVar),Loc,Loc);
7421
7422  // Create the comparison against the array bound.
7423  llvm::APInt Upper
7424    = ArrayTy->getSize().zextOrTrunc(S.Context.getTypeSize(SizeType));
7425  Expr *Comparison
7426    = new (S.Context) BinaryOperator(IterationVarRefRVal,
7427                     IntegerLiteral::Create(S.Context, Upper, SizeType, Loc),
7428                                     BO_NE, S.Context.BoolTy,
7429                                     VK_RValue, OK_Ordinary, Loc);
7430
7431  // Create the pre-increment of the iteration variable.
7432  Expr *Increment
7433    = new (S.Context) UnaryOperator(IterationVarRef, UO_PreInc, SizeType,
7434                                    VK_LValue, OK_Ordinary, Loc);
7435
7436  // Subscript the "from" and "to" expressions with the iteration variable.
7437  From = AssertSuccess(S.CreateBuiltinArraySubscriptExpr(From, Loc,
7438                                                         IterationVarRefRVal,
7439                                                         Loc));
7440  To = AssertSuccess(S.CreateBuiltinArraySubscriptExpr(To, Loc,
7441                                                       IterationVarRefRVal,
7442                                                       Loc));
7443  if (!Copying) // Cast to rvalue
7444    From = CastForMoving(S, From);
7445
7446  // Build the copy/move for an individual element of the array.
7447  StmtResult Copy = BuildSingleCopyAssign(S, Loc, ArrayTy->getElementType(),
7448                                          To, From, CopyingBaseSubobject,
7449                                          Copying, Depth + 1);
7450  if (Copy.isInvalid())
7451    return StmtError();
7452
7453  // Construct the loop that copies all elements of this array.
7454  return S.ActOnForStmt(Loc, Loc, InitStmt,
7455                        S.MakeFullExpr(Comparison),
7456                        0, S.MakeFullExpr(Increment),
7457                        Loc, Copy.take());
7458}
7459
7460/// Determine whether an implicit copy assignment operator for ClassDecl has a
7461/// const argument.
7462/// FIXME: It ought to be possible to store this on the record.
7463static bool isImplicitCopyAssignmentArgConst(Sema &S,
7464                                             CXXRecordDecl *ClassDecl) {
7465  if (ClassDecl->isInvalidDecl())
7466    return true;
7467
7468  // C++ [class.copy]p10:
7469  //   If the class definition does not explicitly declare a copy
7470  //   assignment operator, one is declared implicitly.
7471  //   The implicitly-defined copy assignment operator for a class X
7472  //   will have the form
7473  //
7474  //       X& X::operator=(const X&)
7475  //
7476  //   if
7477  //       -- each direct base class B of X has a copy assignment operator
7478  //          whose parameter is of type const B&, const volatile B& or B,
7479  //          and
7480  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
7481                                       BaseEnd = ClassDecl->bases_end();
7482       Base != BaseEnd; ++Base) {
7483    // We'll handle this below
7484    if (S.getLangOpts().CPlusPlus0x && Base->isVirtual())
7485      continue;
7486
7487    assert(!Base->getType()->isDependentType() &&
7488           "Cannot generate implicit members for class with dependent bases.");
7489    CXXRecordDecl *BaseClassDecl = Base->getType()->getAsCXXRecordDecl();
7490    if (!S.LookupCopyingAssignment(BaseClassDecl, Qualifiers::Const, false, 0))
7491      return false;
7492  }
7493
7494  // In C++11, the above citation has "or virtual" added
7495  if (S.getLangOpts().CPlusPlus0x) {
7496    for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
7497                                         BaseEnd = ClassDecl->vbases_end();
7498         Base != BaseEnd; ++Base) {
7499      assert(!Base->getType()->isDependentType() &&
7500             "Cannot generate implicit members for class with dependent bases.");
7501      CXXRecordDecl *BaseClassDecl = Base->getType()->getAsCXXRecordDecl();
7502      if (!S.LookupCopyingAssignment(BaseClassDecl, Qualifiers::Const,
7503                                     false, 0))
7504        return false;
7505    }
7506  }
7507
7508  //       -- for all the nonstatic data members of X that are of a class
7509  //          type M (or array thereof), each such class type has a copy
7510  //          assignment operator whose parameter is of type const M&,
7511  //          const volatile M& or M.
7512  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
7513                                  FieldEnd = ClassDecl->field_end();
7514       Field != FieldEnd; ++Field) {
7515    QualType FieldType = S.Context.getBaseElementType(Field->getType());
7516    if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl())
7517      if (!S.LookupCopyingAssignment(FieldClassDecl, Qualifiers::Const,
7518                                     false, 0))
7519        return false;
7520  }
7521
7522  //   Otherwise, the implicitly declared copy assignment operator will
7523  //   have the form
7524  //
7525  //       X& X::operator=(X&)
7526
7527  return true;
7528}
7529
7530Sema::ImplicitExceptionSpecification
7531Sema::ComputeDefaultedCopyAssignmentExceptionSpec(CXXMethodDecl *MD) {
7532  CXXRecordDecl *ClassDecl = MD->getParent();
7533
7534  ImplicitExceptionSpecification ExceptSpec(*this);
7535  if (ClassDecl->isInvalidDecl())
7536    return ExceptSpec;
7537
7538  const FunctionProtoType *T = MD->getType()->castAs<FunctionProtoType>();
7539  assert(T->getNumArgs() == 1 && "not a copy assignment op");
7540  unsigned ArgQuals = T->getArgType(0).getNonReferenceType().getCVRQualifiers();
7541
7542  // C++ [except.spec]p14:
7543  //   An implicitly declared special member function (Clause 12) shall have an
7544  //   exception-specification. [...]
7545
7546  // It is unspecified whether or not an implicit copy assignment operator
7547  // attempts to deduplicate calls to assignment operators of virtual bases are
7548  // made. As such, this exception specification is effectively unspecified.
7549  // Based on a similar decision made for constness in C++0x, we're erring on
7550  // the side of assuming such calls to be made regardless of whether they
7551  // actually happen.
7552  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
7553                                       BaseEnd = ClassDecl->bases_end();
7554       Base != BaseEnd; ++Base) {
7555    if (Base->isVirtual())
7556      continue;
7557
7558    CXXRecordDecl *BaseClassDecl
7559      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
7560    if (CXXMethodDecl *CopyAssign = LookupCopyingAssignment(BaseClassDecl,
7561                                                            ArgQuals, false, 0))
7562      ExceptSpec.CalledDecl(Base->getLocStart(), CopyAssign);
7563  }
7564
7565  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
7566                                       BaseEnd = ClassDecl->vbases_end();
7567       Base != BaseEnd; ++Base) {
7568    CXXRecordDecl *BaseClassDecl
7569      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
7570    if (CXXMethodDecl *CopyAssign = LookupCopyingAssignment(BaseClassDecl,
7571                                                            ArgQuals, false, 0))
7572      ExceptSpec.CalledDecl(Base->getLocStart(), CopyAssign);
7573  }
7574
7575  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
7576                                  FieldEnd = ClassDecl->field_end();
7577       Field != FieldEnd;
7578       ++Field) {
7579    QualType FieldType = Context.getBaseElementType(Field->getType());
7580    if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) {
7581      if (CXXMethodDecl *CopyAssign =
7582          LookupCopyingAssignment(FieldClassDecl,
7583                                  ArgQuals | FieldType.getCVRQualifiers(),
7584                                  false, 0))
7585        ExceptSpec.CalledDecl(Field->getLocation(), CopyAssign);
7586    }
7587  }
7588
7589  return ExceptSpec;
7590}
7591
7592CXXMethodDecl *Sema::DeclareImplicitCopyAssignment(CXXRecordDecl *ClassDecl) {
7593  // Note: The following rules are largely analoguous to the copy
7594  // constructor rules. Note that virtual bases are not taken into account
7595  // for determining the argument type of the operator. Note also that
7596  // operators taking an object instead of a reference are allowed.
7597
7598  QualType ArgType = Context.getTypeDeclType(ClassDecl);
7599  QualType RetType = Context.getLValueReferenceType(ArgType);
7600  if (isImplicitCopyAssignmentArgConst(*this, ClassDecl))
7601    ArgType = ArgType.withConst();
7602  ArgType = Context.getLValueReferenceType(ArgType);
7603
7604  //   An implicitly-declared copy assignment operator is an inline public
7605  //   member of its class.
7606  DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
7607  SourceLocation ClassLoc = ClassDecl->getLocation();
7608  DeclarationNameInfo NameInfo(Name, ClassLoc);
7609  CXXMethodDecl *CopyAssignment
7610    = CXXMethodDecl::Create(Context, ClassDecl, ClassLoc, NameInfo, QualType(),
7611                            /*TInfo=*/0, /*isStatic=*/false,
7612                            /*StorageClassAsWritten=*/SC_None,
7613                            /*isInline=*/true, /*isConstexpr=*/false,
7614                            SourceLocation());
7615  CopyAssignment->setAccess(AS_public);
7616  CopyAssignment->setDefaulted();
7617  CopyAssignment->setImplicit();
7618  CopyAssignment->setTrivial(ClassDecl->hasTrivialCopyAssignment());
7619
7620  // Build an exception specification pointing back at this member.
7621  FunctionProtoType::ExtProtoInfo EPI;
7622  EPI.ExceptionSpecType = EST_Unevaluated;
7623  EPI.ExceptionSpecDecl = CopyAssignment;
7624  CopyAssignment->setType(Context.getFunctionType(RetType, &ArgType, 1, EPI));
7625
7626  // Add the parameter to the operator.
7627  ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment,
7628                                               ClassLoc, ClassLoc, /*Id=*/0,
7629                                               ArgType, /*TInfo=*/0,
7630                                               SC_None,
7631                                               SC_None, 0);
7632  CopyAssignment->setParams(FromParam);
7633
7634  // Note that we have added this copy-assignment operator.
7635  ++ASTContext::NumImplicitCopyAssignmentOperatorsDeclared;
7636
7637  if (Scope *S = getScopeForContext(ClassDecl))
7638    PushOnScopeChains(CopyAssignment, S, false);
7639  ClassDecl->addDecl(CopyAssignment);
7640
7641  // C++0x [class.copy]p19:
7642  //   ....  If the class definition does not explicitly declare a copy
7643  //   assignment operator, there is no user-declared move constructor, and
7644  //   there is no user-declared move assignment operator, a copy assignment
7645  //   operator is implicitly declared as defaulted.
7646  if (ShouldDeleteSpecialMember(CopyAssignment, CXXCopyAssignment))
7647    CopyAssignment->setDeletedAsWritten();
7648
7649  AddOverriddenMethods(ClassDecl, CopyAssignment);
7650  return CopyAssignment;
7651}
7652
7653void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
7654                                        CXXMethodDecl *CopyAssignOperator) {
7655  assert((CopyAssignOperator->isDefaulted() &&
7656          CopyAssignOperator->isOverloadedOperator() &&
7657          CopyAssignOperator->getOverloadedOperator() == OO_Equal &&
7658          !CopyAssignOperator->doesThisDeclarationHaveABody() &&
7659          !CopyAssignOperator->isDeleted()) &&
7660         "DefineImplicitCopyAssignment called for wrong function");
7661
7662  CXXRecordDecl *ClassDecl = CopyAssignOperator->getParent();
7663
7664  if (ClassDecl->isInvalidDecl() || CopyAssignOperator->isInvalidDecl()) {
7665    CopyAssignOperator->setInvalidDecl();
7666    return;
7667  }
7668
7669  CopyAssignOperator->setUsed();
7670
7671  ImplicitlyDefinedFunctionScope Scope(*this, CopyAssignOperator);
7672  DiagnosticErrorTrap Trap(Diags);
7673
7674  // C++0x [class.copy]p30:
7675  //   The implicitly-defined or explicitly-defaulted copy assignment operator
7676  //   for a non-union class X performs memberwise copy assignment of its
7677  //   subobjects. The direct base classes of X are assigned first, in the
7678  //   order of their declaration in the base-specifier-list, and then the
7679  //   immediate non-static data members of X are assigned, in the order in
7680  //   which they were declared in the class definition.
7681
7682  // The statements that form the synthesized function body.
7683  ASTOwningVector<Stmt*> Statements(*this);
7684
7685  // The parameter for the "other" object, which we are copying from.
7686  ParmVarDecl *Other = CopyAssignOperator->getParamDecl(0);
7687  Qualifiers OtherQuals = Other->getType().getQualifiers();
7688  QualType OtherRefType = Other->getType();
7689  if (const LValueReferenceType *OtherRef
7690                                = OtherRefType->getAs<LValueReferenceType>()) {
7691    OtherRefType = OtherRef->getPointeeType();
7692    OtherQuals = OtherRefType.getQualifiers();
7693  }
7694
7695  // Our location for everything implicitly-generated.
7696  SourceLocation Loc = CopyAssignOperator->getLocation();
7697
7698  // Construct a reference to the "other" object. We'll be using this
7699  // throughout the generated ASTs.
7700  Expr *OtherRef = BuildDeclRefExpr(Other, OtherRefType, VK_LValue, Loc).take();
7701  assert(OtherRef && "Reference to parameter cannot fail!");
7702
7703  // Construct the "this" pointer. We'll be using this throughout the generated
7704  // ASTs.
7705  Expr *This = ActOnCXXThis(Loc).takeAs<Expr>();
7706  assert(This && "Reference to this cannot fail!");
7707
7708  // Assign base classes.
7709  bool Invalid = false;
7710  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
7711       E = ClassDecl->bases_end(); Base != E; ++Base) {
7712    // Form the assignment:
7713    //   static_cast<Base*>(this)->Base::operator=(static_cast<Base&>(other));
7714    QualType BaseType = Base->getType().getUnqualifiedType();
7715    if (!BaseType->isRecordType()) {
7716      Invalid = true;
7717      continue;
7718    }
7719
7720    CXXCastPath BasePath;
7721    BasePath.push_back(Base);
7722
7723    // Construct the "from" expression, which is an implicit cast to the
7724    // appropriately-qualified base type.
7725    Expr *From = OtherRef;
7726    From = ImpCastExprToType(From, Context.getQualifiedType(BaseType, OtherQuals),
7727                             CK_UncheckedDerivedToBase,
7728                             VK_LValue, &BasePath).take();
7729
7730    // Dereference "this".
7731    ExprResult To = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
7732
7733    // Implicitly cast "this" to the appropriately-qualified base type.
7734    To = ImpCastExprToType(To.take(),
7735                           Context.getCVRQualifiedType(BaseType,
7736                                     CopyAssignOperator->getTypeQualifiers()),
7737                           CK_UncheckedDerivedToBase,
7738                           VK_LValue, &BasePath);
7739
7740    // Build the copy.
7741    StmtResult Copy = BuildSingleCopyAssign(*this, Loc, BaseType,
7742                                            To.get(), From,
7743                                            /*CopyingBaseSubobject=*/true,
7744                                            /*Copying=*/true);
7745    if (Copy.isInvalid()) {
7746      Diag(CurrentLocation, diag::note_member_synthesized_at)
7747        << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
7748      CopyAssignOperator->setInvalidDecl();
7749      return;
7750    }
7751
7752    // Success! Record the copy.
7753    Statements.push_back(Copy.takeAs<Expr>());
7754  }
7755
7756  // \brief Reference to the __builtin_memcpy function.
7757  Expr *BuiltinMemCpyRef = 0;
7758  // \brief Reference to the __builtin_objc_memmove_collectable function.
7759  Expr *CollectableMemCpyRef = 0;
7760
7761  // Assign non-static members.
7762  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
7763                                  FieldEnd = ClassDecl->field_end();
7764       Field != FieldEnd; ++Field) {
7765    if (Field->isUnnamedBitfield())
7766      continue;
7767
7768    // Check for members of reference type; we can't copy those.
7769    if (Field->getType()->isReferenceType()) {
7770      Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
7771        << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
7772      Diag(Field->getLocation(), diag::note_declared_at);
7773      Diag(CurrentLocation, diag::note_member_synthesized_at)
7774        << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
7775      Invalid = true;
7776      continue;
7777    }
7778
7779    // Check for members of const-qualified, non-class type.
7780    QualType BaseType = Context.getBaseElementType(Field->getType());
7781    if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
7782      Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
7783        << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
7784      Diag(Field->getLocation(), diag::note_declared_at);
7785      Diag(CurrentLocation, diag::note_member_synthesized_at)
7786        << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
7787      Invalid = true;
7788      continue;
7789    }
7790
7791    // Suppress assigning zero-width bitfields.
7792    if (Field->isBitField() && Field->getBitWidthValue(Context) == 0)
7793      continue;
7794
7795    QualType FieldType = Field->getType().getNonReferenceType();
7796    if (FieldType->isIncompleteArrayType()) {
7797      assert(ClassDecl->hasFlexibleArrayMember() &&
7798             "Incomplete array type is not valid");
7799      continue;
7800    }
7801
7802    // Build references to the field in the object we're copying from and to.
7803    CXXScopeSpec SS; // Intentionally empty
7804    LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
7805                              LookupMemberName);
7806    MemberLookup.addDecl(*Field);
7807    MemberLookup.resolveKind();
7808    ExprResult From = BuildMemberReferenceExpr(OtherRef, OtherRefType,
7809                                               Loc, /*IsArrow=*/false,
7810                                               SS, SourceLocation(), 0,
7811                                               MemberLookup, 0);
7812    ExprResult To = BuildMemberReferenceExpr(This, This->getType(),
7813                                             Loc, /*IsArrow=*/true,
7814                                             SS, SourceLocation(), 0,
7815                                             MemberLookup, 0);
7816    assert(!From.isInvalid() && "Implicit field reference cannot fail");
7817    assert(!To.isInvalid() && "Implicit field reference cannot fail");
7818
7819    // If the field should be copied with __builtin_memcpy rather than via
7820    // explicit assignments, do so. This optimization only applies for arrays
7821    // of scalars and arrays of class type with trivial copy-assignment
7822    // operators.
7823    if (FieldType->isArrayType() && !FieldType.isVolatileQualified()
7824        && BaseType.hasTrivialAssignment(Context, /*Copying=*/true)) {
7825      // Compute the size of the memory buffer to be copied.
7826      QualType SizeType = Context.getSizeType();
7827      llvm::APInt Size(Context.getTypeSize(SizeType),
7828                       Context.getTypeSizeInChars(BaseType).getQuantity());
7829      for (const ConstantArrayType *Array
7830              = Context.getAsConstantArrayType(FieldType);
7831           Array;
7832           Array = Context.getAsConstantArrayType(Array->getElementType())) {
7833        llvm::APInt ArraySize
7834          = Array->getSize().zextOrTrunc(Size.getBitWidth());
7835        Size *= ArraySize;
7836      }
7837
7838      // Take the address of the field references for "from" and "to".
7839      From = CreateBuiltinUnaryOp(Loc, UO_AddrOf, From.get());
7840      To = CreateBuiltinUnaryOp(Loc, UO_AddrOf, To.get());
7841
7842      bool NeedsCollectableMemCpy =
7843          (BaseType->isRecordType() &&
7844           BaseType->getAs<RecordType>()->getDecl()->hasObjectMember());
7845
7846      if (NeedsCollectableMemCpy) {
7847        if (!CollectableMemCpyRef) {
7848          // Create a reference to the __builtin_objc_memmove_collectable function.
7849          LookupResult R(*this,
7850                         &Context.Idents.get("__builtin_objc_memmove_collectable"),
7851                         Loc, LookupOrdinaryName);
7852          LookupName(R, TUScope, true);
7853
7854          FunctionDecl *CollectableMemCpy = R.getAsSingle<FunctionDecl>();
7855          if (!CollectableMemCpy) {
7856            // Something went horribly wrong earlier, and we will have
7857            // complained about it.
7858            Invalid = true;
7859            continue;
7860          }
7861
7862          CollectableMemCpyRef = BuildDeclRefExpr(CollectableMemCpy,
7863                                                  CollectableMemCpy->getType(),
7864                                                  VK_LValue, Loc, 0).take();
7865          assert(CollectableMemCpyRef && "Builtin reference cannot fail");
7866        }
7867      }
7868      // Create a reference to the __builtin_memcpy builtin function.
7869      else if (!BuiltinMemCpyRef) {
7870        LookupResult R(*this, &Context.Idents.get("__builtin_memcpy"), Loc,
7871                       LookupOrdinaryName);
7872        LookupName(R, TUScope, true);
7873
7874        FunctionDecl *BuiltinMemCpy = R.getAsSingle<FunctionDecl>();
7875        if (!BuiltinMemCpy) {
7876          // Something went horribly wrong earlier, and we will have complained
7877          // about it.
7878          Invalid = true;
7879          continue;
7880        }
7881
7882        BuiltinMemCpyRef = BuildDeclRefExpr(BuiltinMemCpy,
7883                                            BuiltinMemCpy->getType(),
7884                                            VK_LValue, Loc, 0).take();
7885        assert(BuiltinMemCpyRef && "Builtin reference cannot fail");
7886      }
7887
7888      ASTOwningVector<Expr*> CallArgs(*this);
7889      CallArgs.push_back(To.takeAs<Expr>());
7890      CallArgs.push_back(From.takeAs<Expr>());
7891      CallArgs.push_back(IntegerLiteral::Create(Context, Size, SizeType, Loc));
7892      ExprResult Call = ExprError();
7893      if (NeedsCollectableMemCpy)
7894        Call = ActOnCallExpr(/*Scope=*/0,
7895                             CollectableMemCpyRef,
7896                             Loc, move_arg(CallArgs),
7897                             Loc);
7898      else
7899        Call = ActOnCallExpr(/*Scope=*/0,
7900                             BuiltinMemCpyRef,
7901                             Loc, move_arg(CallArgs),
7902                             Loc);
7903
7904      assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!");
7905      Statements.push_back(Call.takeAs<Expr>());
7906      continue;
7907    }
7908
7909    // Build the copy of this field.
7910    StmtResult Copy = BuildSingleCopyAssign(*this, Loc, FieldType,
7911                                            To.get(), From.get(),
7912                                            /*CopyingBaseSubobject=*/false,
7913                                            /*Copying=*/true);
7914    if (Copy.isInvalid()) {
7915      Diag(CurrentLocation, diag::note_member_synthesized_at)
7916        << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
7917      CopyAssignOperator->setInvalidDecl();
7918      return;
7919    }
7920
7921    // Success! Record the copy.
7922    Statements.push_back(Copy.takeAs<Stmt>());
7923  }
7924
7925  if (!Invalid) {
7926    // Add a "return *this;"
7927    ExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
7928
7929    StmtResult Return = ActOnReturnStmt(Loc, ThisObj.get());
7930    if (Return.isInvalid())
7931      Invalid = true;
7932    else {
7933      Statements.push_back(Return.takeAs<Stmt>());
7934
7935      if (Trap.hasErrorOccurred()) {
7936        Diag(CurrentLocation, diag::note_member_synthesized_at)
7937          << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
7938        Invalid = true;
7939      }
7940    }
7941  }
7942
7943  if (Invalid) {
7944    CopyAssignOperator->setInvalidDecl();
7945    return;
7946  }
7947
7948  StmtResult Body;
7949  {
7950    CompoundScopeRAII CompoundScope(*this);
7951    Body = ActOnCompoundStmt(Loc, Loc, move_arg(Statements),
7952                             /*isStmtExpr=*/false);
7953    assert(!Body.isInvalid() && "Compound statement creation cannot fail");
7954  }
7955  CopyAssignOperator->setBody(Body.takeAs<Stmt>());
7956
7957  if (ASTMutationListener *L = getASTMutationListener()) {
7958    L->CompletedImplicitDefinition(CopyAssignOperator);
7959  }
7960}
7961
7962Sema::ImplicitExceptionSpecification
7963Sema::ComputeDefaultedMoveAssignmentExceptionSpec(CXXMethodDecl *MD) {
7964  CXXRecordDecl *ClassDecl = MD->getParent();
7965
7966  ImplicitExceptionSpecification ExceptSpec(*this);
7967  if (ClassDecl->isInvalidDecl())
7968    return ExceptSpec;
7969
7970  // C++0x [except.spec]p14:
7971  //   An implicitly declared special member function (Clause 12) shall have an
7972  //   exception-specification. [...]
7973
7974  // It is unspecified whether or not an implicit move assignment operator
7975  // attempts to deduplicate calls to assignment operators of virtual bases are
7976  // made. As such, this exception specification is effectively unspecified.
7977  // Based on a similar decision made for constness in C++0x, we're erring on
7978  // the side of assuming such calls to be made regardless of whether they
7979  // actually happen.
7980  // Note that a move constructor is not implicitly declared when there are
7981  // virtual bases, but it can still be user-declared and explicitly defaulted.
7982  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
7983                                       BaseEnd = ClassDecl->bases_end();
7984       Base != BaseEnd; ++Base) {
7985    if (Base->isVirtual())
7986      continue;
7987
7988    CXXRecordDecl *BaseClassDecl
7989      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
7990    if (CXXMethodDecl *MoveAssign = LookupMovingAssignment(BaseClassDecl,
7991                                                           0, false, 0))
7992      ExceptSpec.CalledDecl(Base->getLocStart(), MoveAssign);
7993  }
7994
7995  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
7996                                       BaseEnd = ClassDecl->vbases_end();
7997       Base != BaseEnd; ++Base) {
7998    CXXRecordDecl *BaseClassDecl
7999      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8000    if (CXXMethodDecl *MoveAssign = LookupMovingAssignment(BaseClassDecl,
8001                                                           0, false, 0))
8002      ExceptSpec.CalledDecl(Base->getLocStart(), MoveAssign);
8003  }
8004
8005  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
8006                                  FieldEnd = ClassDecl->field_end();
8007       Field != FieldEnd;
8008       ++Field) {
8009    QualType FieldType = Context.getBaseElementType(Field->getType());
8010    if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) {
8011      if (CXXMethodDecl *MoveAssign =
8012              LookupMovingAssignment(FieldClassDecl,
8013                                     FieldType.getCVRQualifiers(),
8014                                     false, 0))
8015        ExceptSpec.CalledDecl(Field->getLocation(), MoveAssign);
8016    }
8017  }
8018
8019  return ExceptSpec;
8020}
8021
8022/// Determine whether the class type has any direct or indirect virtual base
8023/// classes which have a non-trivial move assignment operator.
8024static bool
8025hasVirtualBaseWithNonTrivialMoveAssignment(Sema &S, CXXRecordDecl *ClassDecl) {
8026  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
8027                                          BaseEnd = ClassDecl->vbases_end();
8028       Base != BaseEnd; ++Base) {
8029    CXXRecordDecl *BaseClass =
8030        cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8031
8032    // Try to declare the move assignment. If it would be deleted, then the
8033    // class does not have a non-trivial move assignment.
8034    if (BaseClass->needsImplicitMoveAssignment())
8035      S.DeclareImplicitMoveAssignment(BaseClass);
8036
8037    // If the class has both a trivial move assignment and a non-trivial move
8038    // assignment, hasTrivialMoveAssignment() is false.
8039    if (BaseClass->hasDeclaredMoveAssignment() &&
8040        !BaseClass->hasTrivialMoveAssignment())
8041      return true;
8042  }
8043
8044  return false;
8045}
8046
8047/// Determine whether the given type either has a move constructor or is
8048/// trivially copyable.
8049static bool
8050hasMoveOrIsTriviallyCopyable(Sema &S, QualType Type, bool IsConstructor) {
8051  Type = S.Context.getBaseElementType(Type);
8052
8053  // FIXME: Technically, non-trivially-copyable non-class types, such as
8054  // reference types, are supposed to return false here, but that appears
8055  // to be a standard defect.
8056  CXXRecordDecl *ClassDecl = Type->getAsCXXRecordDecl();
8057  if (!ClassDecl || !ClassDecl->getDefinition())
8058    return true;
8059
8060  if (Type.isTriviallyCopyableType(S.Context))
8061    return true;
8062
8063  if (IsConstructor) {
8064    if (ClassDecl->needsImplicitMoveConstructor())
8065      S.DeclareImplicitMoveConstructor(ClassDecl);
8066    return ClassDecl->hasDeclaredMoveConstructor();
8067  }
8068
8069  if (ClassDecl->needsImplicitMoveAssignment())
8070    S.DeclareImplicitMoveAssignment(ClassDecl);
8071  return ClassDecl->hasDeclaredMoveAssignment();
8072}
8073
8074/// Determine whether all non-static data members and direct or virtual bases
8075/// of class \p ClassDecl have either a move operation, or are trivially
8076/// copyable.
8077static bool subobjectsHaveMoveOrTrivialCopy(Sema &S, CXXRecordDecl *ClassDecl,
8078                                            bool IsConstructor) {
8079  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
8080                                          BaseEnd = ClassDecl->bases_end();
8081       Base != BaseEnd; ++Base) {
8082    if (Base->isVirtual())
8083      continue;
8084
8085    if (!hasMoveOrIsTriviallyCopyable(S, Base->getType(), IsConstructor))
8086      return false;
8087  }
8088
8089  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
8090                                          BaseEnd = ClassDecl->vbases_end();
8091       Base != BaseEnd; ++Base) {
8092    if (!hasMoveOrIsTriviallyCopyable(S, Base->getType(), IsConstructor))
8093      return false;
8094  }
8095
8096  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
8097                                     FieldEnd = ClassDecl->field_end();
8098       Field != FieldEnd; ++Field) {
8099    if (!hasMoveOrIsTriviallyCopyable(S, Field->getType(), IsConstructor))
8100      return false;
8101  }
8102
8103  return true;
8104}
8105
8106CXXMethodDecl *Sema::DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl) {
8107  // C++11 [class.copy]p20:
8108  //   If the definition of a class X does not explicitly declare a move
8109  //   assignment operator, one will be implicitly declared as defaulted
8110  //   if and only if:
8111  //
8112  //   - [first 4 bullets]
8113  assert(ClassDecl->needsImplicitMoveAssignment());
8114
8115  // [Checked after we build the declaration]
8116  //   - the move assignment operator would not be implicitly defined as
8117  //     deleted,
8118
8119  // [DR1402]:
8120  //   - X has no direct or indirect virtual base class with a non-trivial
8121  //     move assignment operator, and
8122  //   - each of X's non-static data members and direct or virtual base classes
8123  //     has a type that either has a move assignment operator or is trivially
8124  //     copyable.
8125  if (hasVirtualBaseWithNonTrivialMoveAssignment(*this, ClassDecl) ||
8126      !subobjectsHaveMoveOrTrivialCopy(*this, ClassDecl,/*Constructor*/false)) {
8127    ClassDecl->setFailedImplicitMoveAssignment();
8128    return 0;
8129  }
8130
8131  // Note: The following rules are largely analoguous to the move
8132  // constructor rules.
8133
8134  QualType ArgType = Context.getTypeDeclType(ClassDecl);
8135  QualType RetType = Context.getLValueReferenceType(ArgType);
8136  ArgType = Context.getRValueReferenceType(ArgType);
8137
8138  //   An implicitly-declared move assignment operator is an inline public
8139  //   member of its class.
8140  DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
8141  SourceLocation ClassLoc = ClassDecl->getLocation();
8142  DeclarationNameInfo NameInfo(Name, ClassLoc);
8143  CXXMethodDecl *MoveAssignment
8144    = CXXMethodDecl::Create(Context, ClassDecl, ClassLoc, NameInfo, QualType(),
8145                            /*TInfo=*/0, /*isStatic=*/false,
8146                            /*StorageClassAsWritten=*/SC_None,
8147                            /*isInline=*/true,
8148                            /*isConstexpr=*/false,
8149                            SourceLocation());
8150  MoveAssignment->setAccess(AS_public);
8151  MoveAssignment->setDefaulted();
8152  MoveAssignment->setImplicit();
8153  MoveAssignment->setTrivial(ClassDecl->hasTrivialMoveAssignment());
8154
8155  // Build an exception specification pointing back at this member.
8156  FunctionProtoType::ExtProtoInfo EPI;
8157  EPI.ExceptionSpecType = EST_Unevaluated;
8158  EPI.ExceptionSpecDecl = MoveAssignment;
8159  MoveAssignment->setType(Context.getFunctionType(RetType, &ArgType, 1, EPI));
8160
8161  // Add the parameter to the operator.
8162  ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveAssignment,
8163                                               ClassLoc, ClassLoc, /*Id=*/0,
8164                                               ArgType, /*TInfo=*/0,
8165                                               SC_None,
8166                                               SC_None, 0);
8167  MoveAssignment->setParams(FromParam);
8168
8169  // Note that we have added this copy-assignment operator.
8170  ++ASTContext::NumImplicitMoveAssignmentOperatorsDeclared;
8171
8172  // C++0x [class.copy]p9:
8173  //   If the definition of a class X does not explicitly declare a move
8174  //   assignment operator, one will be implicitly declared as defaulted if and
8175  //   only if:
8176  //   [...]
8177  //   - the move assignment operator would not be implicitly defined as
8178  //     deleted.
8179  if (ShouldDeleteSpecialMember(MoveAssignment, CXXMoveAssignment)) {
8180    // Cache this result so that we don't try to generate this over and over
8181    // on every lookup, leaking memory and wasting time.
8182    ClassDecl->setFailedImplicitMoveAssignment();
8183    return 0;
8184  }
8185
8186  if (Scope *S = getScopeForContext(ClassDecl))
8187    PushOnScopeChains(MoveAssignment, S, false);
8188  ClassDecl->addDecl(MoveAssignment);
8189
8190  AddOverriddenMethods(ClassDecl, MoveAssignment);
8191  return MoveAssignment;
8192}
8193
8194void Sema::DefineImplicitMoveAssignment(SourceLocation CurrentLocation,
8195                                        CXXMethodDecl *MoveAssignOperator) {
8196  assert((MoveAssignOperator->isDefaulted() &&
8197          MoveAssignOperator->isOverloadedOperator() &&
8198          MoveAssignOperator->getOverloadedOperator() == OO_Equal &&
8199          !MoveAssignOperator->doesThisDeclarationHaveABody() &&
8200          !MoveAssignOperator->isDeleted()) &&
8201         "DefineImplicitMoveAssignment called for wrong function");
8202
8203  CXXRecordDecl *ClassDecl = MoveAssignOperator->getParent();
8204
8205  if (ClassDecl->isInvalidDecl() || MoveAssignOperator->isInvalidDecl()) {
8206    MoveAssignOperator->setInvalidDecl();
8207    return;
8208  }
8209
8210  MoveAssignOperator->setUsed();
8211
8212  ImplicitlyDefinedFunctionScope Scope(*this, MoveAssignOperator);
8213  DiagnosticErrorTrap Trap(Diags);
8214
8215  // C++0x [class.copy]p28:
8216  //   The implicitly-defined or move assignment operator for a non-union class
8217  //   X performs memberwise move assignment of its subobjects. The direct base
8218  //   classes of X are assigned first, in the order of their declaration in the
8219  //   base-specifier-list, and then the immediate non-static data members of X
8220  //   are assigned, in the order in which they were declared in the class
8221  //   definition.
8222
8223  // The statements that form the synthesized function body.
8224  ASTOwningVector<Stmt*> Statements(*this);
8225
8226  // The parameter for the "other" object, which we are move from.
8227  ParmVarDecl *Other = MoveAssignOperator->getParamDecl(0);
8228  QualType OtherRefType = Other->getType()->
8229      getAs<RValueReferenceType>()->getPointeeType();
8230  assert(OtherRefType.getQualifiers() == 0 &&
8231         "Bad argument type of defaulted move assignment");
8232
8233  // Our location for everything implicitly-generated.
8234  SourceLocation Loc = MoveAssignOperator->getLocation();
8235
8236  // Construct a reference to the "other" object. We'll be using this
8237  // throughout the generated ASTs.
8238  Expr *OtherRef = BuildDeclRefExpr(Other, OtherRefType, VK_LValue, Loc).take();
8239  assert(OtherRef && "Reference to parameter cannot fail!");
8240  // Cast to rvalue.
8241  OtherRef = CastForMoving(*this, OtherRef);
8242
8243  // Construct the "this" pointer. We'll be using this throughout the generated
8244  // ASTs.
8245  Expr *This = ActOnCXXThis(Loc).takeAs<Expr>();
8246  assert(This && "Reference to this cannot fail!");
8247
8248  // Assign base classes.
8249  bool Invalid = false;
8250  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
8251       E = ClassDecl->bases_end(); Base != E; ++Base) {
8252    // Form the assignment:
8253    //   static_cast<Base*>(this)->Base::operator=(static_cast<Base&&>(other));
8254    QualType BaseType = Base->getType().getUnqualifiedType();
8255    if (!BaseType->isRecordType()) {
8256      Invalid = true;
8257      continue;
8258    }
8259
8260    CXXCastPath BasePath;
8261    BasePath.push_back(Base);
8262
8263    // Construct the "from" expression, which is an implicit cast to the
8264    // appropriately-qualified base type.
8265    Expr *From = OtherRef;
8266    From = ImpCastExprToType(From, BaseType, CK_UncheckedDerivedToBase,
8267                             VK_XValue, &BasePath).take();
8268
8269    // Dereference "this".
8270    ExprResult To = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
8271
8272    // Implicitly cast "this" to the appropriately-qualified base type.
8273    To = ImpCastExprToType(To.take(),
8274                           Context.getCVRQualifiedType(BaseType,
8275                                     MoveAssignOperator->getTypeQualifiers()),
8276                           CK_UncheckedDerivedToBase,
8277                           VK_LValue, &BasePath);
8278
8279    // Build the move.
8280    StmtResult Move = BuildSingleCopyAssign(*this, Loc, BaseType,
8281                                            To.get(), From,
8282                                            /*CopyingBaseSubobject=*/true,
8283                                            /*Copying=*/false);
8284    if (Move.isInvalid()) {
8285      Diag(CurrentLocation, diag::note_member_synthesized_at)
8286        << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8287      MoveAssignOperator->setInvalidDecl();
8288      return;
8289    }
8290
8291    // Success! Record the move.
8292    Statements.push_back(Move.takeAs<Expr>());
8293  }
8294
8295  // \brief Reference to the __builtin_memcpy function.
8296  Expr *BuiltinMemCpyRef = 0;
8297  // \brief Reference to the __builtin_objc_memmove_collectable function.
8298  Expr *CollectableMemCpyRef = 0;
8299
8300  // Assign non-static members.
8301  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
8302                                  FieldEnd = ClassDecl->field_end();
8303       Field != FieldEnd; ++Field) {
8304    if (Field->isUnnamedBitfield())
8305      continue;
8306
8307    // Check for members of reference type; we can't move those.
8308    if (Field->getType()->isReferenceType()) {
8309      Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
8310        << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
8311      Diag(Field->getLocation(), diag::note_declared_at);
8312      Diag(CurrentLocation, diag::note_member_synthesized_at)
8313        << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8314      Invalid = true;
8315      continue;
8316    }
8317
8318    // Check for members of const-qualified, non-class type.
8319    QualType BaseType = Context.getBaseElementType(Field->getType());
8320    if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
8321      Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
8322        << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
8323      Diag(Field->getLocation(), diag::note_declared_at);
8324      Diag(CurrentLocation, diag::note_member_synthesized_at)
8325        << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8326      Invalid = true;
8327      continue;
8328    }
8329
8330    // Suppress assigning zero-width bitfields.
8331    if (Field->isBitField() && Field->getBitWidthValue(Context) == 0)
8332      continue;
8333
8334    QualType FieldType = Field->getType().getNonReferenceType();
8335    if (FieldType->isIncompleteArrayType()) {
8336      assert(ClassDecl->hasFlexibleArrayMember() &&
8337             "Incomplete array type is not valid");
8338      continue;
8339    }
8340
8341    // Build references to the field in the object we're copying from and to.
8342    CXXScopeSpec SS; // Intentionally empty
8343    LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
8344                              LookupMemberName);
8345    MemberLookup.addDecl(*Field);
8346    MemberLookup.resolveKind();
8347    ExprResult From = BuildMemberReferenceExpr(OtherRef, OtherRefType,
8348                                               Loc, /*IsArrow=*/false,
8349                                               SS, SourceLocation(), 0,
8350                                               MemberLookup, 0);
8351    ExprResult To = BuildMemberReferenceExpr(This, This->getType(),
8352                                             Loc, /*IsArrow=*/true,
8353                                             SS, SourceLocation(), 0,
8354                                             MemberLookup, 0);
8355    assert(!From.isInvalid() && "Implicit field reference cannot fail");
8356    assert(!To.isInvalid() && "Implicit field reference cannot fail");
8357
8358    assert(!From.get()->isLValue() && // could be xvalue or prvalue
8359        "Member reference with rvalue base must be rvalue except for reference "
8360        "members, which aren't allowed for move assignment.");
8361
8362    // If the field should be copied with __builtin_memcpy rather than via
8363    // explicit assignments, do so. This optimization only applies for arrays
8364    // of scalars and arrays of class type with trivial move-assignment
8365    // operators.
8366    if (FieldType->isArrayType() && !FieldType.isVolatileQualified()
8367        && BaseType.hasTrivialAssignment(Context, /*Copying=*/false)) {
8368      // Compute the size of the memory buffer to be copied.
8369      QualType SizeType = Context.getSizeType();
8370      llvm::APInt Size(Context.getTypeSize(SizeType),
8371                       Context.getTypeSizeInChars(BaseType).getQuantity());
8372      for (const ConstantArrayType *Array
8373              = Context.getAsConstantArrayType(FieldType);
8374           Array;
8375           Array = Context.getAsConstantArrayType(Array->getElementType())) {
8376        llvm::APInt ArraySize
8377          = Array->getSize().zextOrTrunc(Size.getBitWidth());
8378        Size *= ArraySize;
8379      }
8380
8381      // Take the address of the field references for "from" and "to". We
8382      // directly construct UnaryOperators here because semantic analysis
8383      // does not permit us to take the address of an xvalue.
8384      From = new (Context) UnaryOperator(From.get(), UO_AddrOf,
8385                             Context.getPointerType(From.get()->getType()),
8386                             VK_RValue, OK_Ordinary, Loc);
8387      To = new (Context) UnaryOperator(To.get(), UO_AddrOf,
8388                           Context.getPointerType(To.get()->getType()),
8389                           VK_RValue, OK_Ordinary, Loc);
8390
8391      bool NeedsCollectableMemCpy =
8392          (BaseType->isRecordType() &&
8393           BaseType->getAs<RecordType>()->getDecl()->hasObjectMember());
8394
8395      if (NeedsCollectableMemCpy) {
8396        if (!CollectableMemCpyRef) {
8397          // Create a reference to the __builtin_objc_memmove_collectable function.
8398          LookupResult R(*this,
8399                         &Context.Idents.get("__builtin_objc_memmove_collectable"),
8400                         Loc, LookupOrdinaryName);
8401          LookupName(R, TUScope, true);
8402
8403          FunctionDecl *CollectableMemCpy = R.getAsSingle<FunctionDecl>();
8404          if (!CollectableMemCpy) {
8405            // Something went horribly wrong earlier, and we will have
8406            // complained about it.
8407            Invalid = true;
8408            continue;
8409          }
8410
8411          CollectableMemCpyRef = BuildDeclRefExpr(CollectableMemCpy,
8412                                                  CollectableMemCpy->getType(),
8413                                                  VK_LValue, Loc, 0).take();
8414          assert(CollectableMemCpyRef && "Builtin reference cannot fail");
8415        }
8416      }
8417      // Create a reference to the __builtin_memcpy builtin function.
8418      else if (!BuiltinMemCpyRef) {
8419        LookupResult R(*this, &Context.Idents.get("__builtin_memcpy"), Loc,
8420                       LookupOrdinaryName);
8421        LookupName(R, TUScope, true);
8422
8423        FunctionDecl *BuiltinMemCpy = R.getAsSingle<FunctionDecl>();
8424        if (!BuiltinMemCpy) {
8425          // Something went horribly wrong earlier, and we will have complained
8426          // about it.
8427          Invalid = true;
8428          continue;
8429        }
8430
8431        BuiltinMemCpyRef = BuildDeclRefExpr(BuiltinMemCpy,
8432                                            BuiltinMemCpy->getType(),
8433                                            VK_LValue, Loc, 0).take();
8434        assert(BuiltinMemCpyRef && "Builtin reference cannot fail");
8435      }
8436
8437      ASTOwningVector<Expr*> CallArgs(*this);
8438      CallArgs.push_back(To.takeAs<Expr>());
8439      CallArgs.push_back(From.takeAs<Expr>());
8440      CallArgs.push_back(IntegerLiteral::Create(Context, Size, SizeType, Loc));
8441      ExprResult Call = ExprError();
8442      if (NeedsCollectableMemCpy)
8443        Call = ActOnCallExpr(/*Scope=*/0,
8444                             CollectableMemCpyRef,
8445                             Loc, move_arg(CallArgs),
8446                             Loc);
8447      else
8448        Call = ActOnCallExpr(/*Scope=*/0,
8449                             BuiltinMemCpyRef,
8450                             Loc, move_arg(CallArgs),
8451                             Loc);
8452
8453      assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!");
8454      Statements.push_back(Call.takeAs<Expr>());
8455      continue;
8456    }
8457
8458    // Build the move of this field.
8459    StmtResult Move = BuildSingleCopyAssign(*this, Loc, FieldType,
8460                                            To.get(), From.get(),
8461                                            /*CopyingBaseSubobject=*/false,
8462                                            /*Copying=*/false);
8463    if (Move.isInvalid()) {
8464      Diag(CurrentLocation, diag::note_member_synthesized_at)
8465        << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8466      MoveAssignOperator->setInvalidDecl();
8467      return;
8468    }
8469
8470    // Success! Record the copy.
8471    Statements.push_back(Move.takeAs<Stmt>());
8472  }
8473
8474  if (!Invalid) {
8475    // Add a "return *this;"
8476    ExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
8477
8478    StmtResult Return = ActOnReturnStmt(Loc, ThisObj.get());
8479    if (Return.isInvalid())
8480      Invalid = true;
8481    else {
8482      Statements.push_back(Return.takeAs<Stmt>());
8483
8484      if (Trap.hasErrorOccurred()) {
8485        Diag(CurrentLocation, diag::note_member_synthesized_at)
8486          << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8487        Invalid = true;
8488      }
8489    }
8490  }
8491
8492  if (Invalid) {
8493    MoveAssignOperator->setInvalidDecl();
8494    return;
8495  }
8496
8497  StmtResult Body;
8498  {
8499    CompoundScopeRAII CompoundScope(*this);
8500    Body = ActOnCompoundStmt(Loc, Loc, move_arg(Statements),
8501                             /*isStmtExpr=*/false);
8502    assert(!Body.isInvalid() && "Compound statement creation cannot fail");
8503  }
8504  MoveAssignOperator->setBody(Body.takeAs<Stmt>());
8505
8506  if (ASTMutationListener *L = getASTMutationListener()) {
8507    L->CompletedImplicitDefinition(MoveAssignOperator);
8508  }
8509}
8510
8511/// Determine whether an implicit copy constructor for ClassDecl has a const
8512/// argument.
8513/// FIXME: It ought to be possible to store this on the record.
8514static bool isImplicitCopyCtorArgConst(Sema &S, CXXRecordDecl *ClassDecl) {
8515  if (ClassDecl->isInvalidDecl())
8516    return true;
8517
8518  // C++ [class.copy]p5:
8519  //   The implicitly-declared copy constructor for a class X will
8520  //   have the form
8521  //
8522  //       X::X(const X&)
8523  //
8524  //   if
8525  //     -- each direct or virtual base class B of X has a copy
8526  //        constructor whose first parameter is of type const B& or
8527  //        const volatile B&, and
8528  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
8529                                       BaseEnd = ClassDecl->bases_end();
8530       Base != BaseEnd; ++Base) {
8531    // Virtual bases are handled below.
8532    if (Base->isVirtual())
8533      continue;
8534
8535    CXXRecordDecl *BaseClassDecl
8536      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8537    // FIXME: This lookup is wrong. If the copy ctor for a member or base is
8538    // ambiguous, we should still produce a constructor with a const-qualified
8539    // parameter.
8540    if (!S.LookupCopyingConstructor(BaseClassDecl, Qualifiers::Const))
8541      return false;
8542  }
8543
8544  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
8545                                       BaseEnd = ClassDecl->vbases_end();
8546       Base != BaseEnd; ++Base) {
8547    CXXRecordDecl *BaseClassDecl
8548      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8549    if (!S.LookupCopyingConstructor(BaseClassDecl, Qualifiers::Const))
8550      return false;
8551  }
8552
8553  //     -- for all the nonstatic data members of X that are of a
8554  //        class type M (or array thereof), each such class type
8555  //        has a copy constructor whose first parameter is of type
8556  //        const M& or const volatile M&.
8557  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
8558                                  FieldEnd = ClassDecl->field_end();
8559       Field != FieldEnd; ++Field) {
8560    QualType FieldType = S.Context.getBaseElementType(Field->getType());
8561    if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) {
8562      if (!S.LookupCopyingConstructor(FieldClassDecl, Qualifiers::Const))
8563        return false;
8564    }
8565  }
8566
8567  //   Otherwise, the implicitly declared copy constructor will have
8568  //   the form
8569  //
8570  //       X::X(X&)
8571
8572  return true;
8573}
8574
8575Sema::ImplicitExceptionSpecification
8576Sema::ComputeDefaultedCopyCtorExceptionSpec(CXXMethodDecl *MD) {
8577  CXXRecordDecl *ClassDecl = MD->getParent();
8578
8579  ImplicitExceptionSpecification ExceptSpec(*this);
8580  if (ClassDecl->isInvalidDecl())
8581    return ExceptSpec;
8582
8583  const FunctionProtoType *T = MD->getType()->castAs<FunctionProtoType>();
8584  assert(T->getNumArgs() >= 1 && "not a copy ctor");
8585  unsigned Quals = T->getArgType(0).getNonReferenceType().getCVRQualifiers();
8586
8587  // C++ [except.spec]p14:
8588  //   An implicitly declared special member function (Clause 12) shall have an
8589  //   exception-specification. [...]
8590  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
8591                                       BaseEnd = ClassDecl->bases_end();
8592       Base != BaseEnd;
8593       ++Base) {
8594    // Virtual bases are handled below.
8595    if (Base->isVirtual())
8596      continue;
8597
8598    CXXRecordDecl *BaseClassDecl
8599      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8600    if (CXXConstructorDecl *CopyConstructor =
8601          LookupCopyingConstructor(BaseClassDecl, Quals))
8602      ExceptSpec.CalledDecl(Base->getLocStart(), CopyConstructor);
8603  }
8604  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
8605                                       BaseEnd = ClassDecl->vbases_end();
8606       Base != BaseEnd;
8607       ++Base) {
8608    CXXRecordDecl *BaseClassDecl
8609      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8610    if (CXXConstructorDecl *CopyConstructor =
8611          LookupCopyingConstructor(BaseClassDecl, Quals))
8612      ExceptSpec.CalledDecl(Base->getLocStart(), CopyConstructor);
8613  }
8614  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
8615                                  FieldEnd = ClassDecl->field_end();
8616       Field != FieldEnd;
8617       ++Field) {
8618    QualType FieldType = Context.getBaseElementType(Field->getType());
8619    if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) {
8620      if (CXXConstructorDecl *CopyConstructor =
8621              LookupCopyingConstructor(FieldClassDecl,
8622                                       Quals | FieldType.getCVRQualifiers()))
8623      ExceptSpec.CalledDecl(Field->getLocation(), CopyConstructor);
8624    }
8625  }
8626
8627  return ExceptSpec;
8628}
8629
8630CXXConstructorDecl *Sema::DeclareImplicitCopyConstructor(
8631                                                    CXXRecordDecl *ClassDecl) {
8632  // C++ [class.copy]p4:
8633  //   If the class definition does not explicitly declare a copy
8634  //   constructor, one is declared implicitly.
8635
8636  QualType ClassType = Context.getTypeDeclType(ClassDecl);
8637  QualType ArgType = ClassType;
8638  bool Const = isImplicitCopyCtorArgConst(*this, ClassDecl);
8639  if (Const)
8640    ArgType = ArgType.withConst();
8641  ArgType = Context.getLValueReferenceType(ArgType);
8642
8643  bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
8644                                                     CXXCopyConstructor,
8645                                                     Const);
8646
8647  DeclarationName Name
8648    = Context.DeclarationNames.getCXXConstructorName(
8649                                           Context.getCanonicalType(ClassType));
8650  SourceLocation ClassLoc = ClassDecl->getLocation();
8651  DeclarationNameInfo NameInfo(Name, ClassLoc);
8652
8653  //   An implicitly-declared copy constructor is an inline public
8654  //   member of its class.
8655  CXXConstructorDecl *CopyConstructor = CXXConstructorDecl::Create(
8656      Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/0,
8657      /*isExplicit=*/false, /*isInline=*/true, /*isImplicitlyDeclared=*/true,
8658      Constexpr);
8659  CopyConstructor->setAccess(AS_public);
8660  CopyConstructor->setDefaulted();
8661  CopyConstructor->setTrivial(ClassDecl->hasTrivialCopyConstructor());
8662
8663  // Build an exception specification pointing back at this member.
8664  FunctionProtoType::ExtProtoInfo EPI;
8665  EPI.ExceptionSpecType = EST_Unevaluated;
8666  EPI.ExceptionSpecDecl = CopyConstructor;
8667  CopyConstructor->setType(
8668      Context.getFunctionType(Context.VoidTy, &ArgType, 1, EPI));
8669
8670  // Note that we have declared this constructor.
8671  ++ASTContext::NumImplicitCopyConstructorsDeclared;
8672
8673  // Add the parameter to the constructor.
8674  ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyConstructor,
8675                                               ClassLoc, ClassLoc,
8676                                               /*IdentifierInfo=*/0,
8677                                               ArgType, /*TInfo=*/0,
8678                                               SC_None,
8679                                               SC_None, 0);
8680  CopyConstructor->setParams(FromParam);
8681
8682  if (Scope *S = getScopeForContext(ClassDecl))
8683    PushOnScopeChains(CopyConstructor, S, false);
8684  ClassDecl->addDecl(CopyConstructor);
8685
8686  // C++11 [class.copy]p8:
8687  //   ... If the class definition does not explicitly declare a copy
8688  //   constructor, there is no user-declared move constructor, and there is no
8689  //   user-declared move assignment operator, a copy constructor is implicitly
8690  //   declared as defaulted.
8691  if (ShouldDeleteSpecialMember(CopyConstructor, CXXCopyConstructor))
8692    CopyConstructor->setDeletedAsWritten();
8693
8694  return CopyConstructor;
8695}
8696
8697void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
8698                                   CXXConstructorDecl *CopyConstructor) {
8699  assert((CopyConstructor->isDefaulted() &&
8700          CopyConstructor->isCopyConstructor() &&
8701          !CopyConstructor->doesThisDeclarationHaveABody() &&
8702          !CopyConstructor->isDeleted()) &&
8703         "DefineImplicitCopyConstructor - call it for implicit copy ctor");
8704
8705  CXXRecordDecl *ClassDecl = CopyConstructor->getParent();
8706  assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor");
8707
8708  ImplicitlyDefinedFunctionScope Scope(*this, CopyConstructor);
8709  DiagnosticErrorTrap Trap(Diags);
8710
8711  if (SetCtorInitializers(CopyConstructor, 0, 0, /*AnyErrors=*/false) ||
8712      Trap.hasErrorOccurred()) {
8713    Diag(CurrentLocation, diag::note_member_synthesized_at)
8714      << CXXCopyConstructor << Context.getTagDeclType(ClassDecl);
8715    CopyConstructor->setInvalidDecl();
8716  }  else {
8717    Sema::CompoundScopeRAII CompoundScope(*this);
8718    CopyConstructor->setBody(ActOnCompoundStmt(CopyConstructor->getLocation(),
8719                                               CopyConstructor->getLocation(),
8720                                               MultiStmtArg(*this, 0, 0),
8721                                               /*isStmtExpr=*/false)
8722                                                              .takeAs<Stmt>());
8723    CopyConstructor->setImplicitlyDefined(true);
8724  }
8725
8726  CopyConstructor->setUsed();
8727  if (ASTMutationListener *L = getASTMutationListener()) {
8728    L->CompletedImplicitDefinition(CopyConstructor);
8729  }
8730}
8731
8732Sema::ImplicitExceptionSpecification
8733Sema::ComputeDefaultedMoveCtorExceptionSpec(CXXMethodDecl *MD) {
8734  CXXRecordDecl *ClassDecl = MD->getParent();
8735
8736  // C++ [except.spec]p14:
8737  //   An implicitly declared special member function (Clause 12) shall have an
8738  //   exception-specification. [...]
8739  ImplicitExceptionSpecification ExceptSpec(*this);
8740  if (ClassDecl->isInvalidDecl())
8741    return ExceptSpec;
8742
8743  // Direct base-class constructors.
8744  for (CXXRecordDecl::base_class_iterator B = ClassDecl->bases_begin(),
8745                                       BEnd = ClassDecl->bases_end();
8746       B != BEnd; ++B) {
8747    if (B->isVirtual()) // Handled below.
8748      continue;
8749
8750    if (const RecordType *BaseType = B->getType()->getAs<RecordType>()) {
8751      CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
8752      CXXConstructorDecl *Constructor =
8753          LookupMovingConstructor(BaseClassDecl, 0);
8754      // If this is a deleted function, add it anyway. This might be conformant
8755      // with the standard. This might not. I'm not sure. It might not matter.
8756      if (Constructor)
8757        ExceptSpec.CalledDecl(B->getLocStart(), Constructor);
8758    }
8759  }
8760
8761  // Virtual base-class constructors.
8762  for (CXXRecordDecl::base_class_iterator B = ClassDecl->vbases_begin(),
8763                                       BEnd = ClassDecl->vbases_end();
8764       B != BEnd; ++B) {
8765    if (const RecordType *BaseType = B->getType()->getAs<RecordType>()) {
8766      CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
8767      CXXConstructorDecl *Constructor =
8768          LookupMovingConstructor(BaseClassDecl, 0);
8769      // If this is a deleted function, add it anyway. This might be conformant
8770      // with the standard. This might not. I'm not sure. It might not matter.
8771      if (Constructor)
8772        ExceptSpec.CalledDecl(B->getLocStart(), Constructor);
8773    }
8774  }
8775
8776  // Field constructors.
8777  for (RecordDecl::field_iterator F = ClassDecl->field_begin(),
8778                               FEnd = ClassDecl->field_end();
8779       F != FEnd; ++F) {
8780    QualType FieldType = Context.getBaseElementType(F->getType());
8781    if (CXXRecordDecl *FieldRecDecl = FieldType->getAsCXXRecordDecl()) {
8782      CXXConstructorDecl *Constructor =
8783          LookupMovingConstructor(FieldRecDecl, FieldType.getCVRQualifiers());
8784      // If this is a deleted function, add it anyway. This might be conformant
8785      // with the standard. This might not. I'm not sure. It might not matter.
8786      // In particular, the problem is that this function never gets called. It
8787      // might just be ill-formed because this function attempts to refer to
8788      // a deleted function here.
8789      if (Constructor)
8790        ExceptSpec.CalledDecl(F->getLocation(), Constructor);
8791    }
8792  }
8793
8794  return ExceptSpec;
8795}
8796
8797CXXConstructorDecl *Sema::DeclareImplicitMoveConstructor(
8798                                                    CXXRecordDecl *ClassDecl) {
8799  // C++11 [class.copy]p9:
8800  //   If the definition of a class X does not explicitly declare a move
8801  //   constructor, one will be implicitly declared as defaulted if and only if:
8802  //
8803  //   - [first 4 bullets]
8804  assert(ClassDecl->needsImplicitMoveConstructor());
8805
8806  // [Checked after we build the declaration]
8807  //   - the move assignment operator would not be implicitly defined as
8808  //     deleted,
8809
8810  // [DR1402]:
8811  //   - each of X's non-static data members and direct or virtual base classes
8812  //     has a type that either has a move constructor or is trivially copyable.
8813  if (!subobjectsHaveMoveOrTrivialCopy(*this, ClassDecl, /*Constructor*/true)) {
8814    ClassDecl->setFailedImplicitMoveConstructor();
8815    return 0;
8816  }
8817
8818  QualType ClassType = Context.getTypeDeclType(ClassDecl);
8819  QualType ArgType = Context.getRValueReferenceType(ClassType);
8820
8821  bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
8822                                                     CXXMoveConstructor,
8823                                                     false);
8824
8825  DeclarationName Name
8826    = Context.DeclarationNames.getCXXConstructorName(
8827                                           Context.getCanonicalType(ClassType));
8828  SourceLocation ClassLoc = ClassDecl->getLocation();
8829  DeclarationNameInfo NameInfo(Name, ClassLoc);
8830
8831  // C++0x [class.copy]p11:
8832  //   An implicitly-declared copy/move constructor is an inline public
8833  //   member of its class.
8834  CXXConstructorDecl *MoveConstructor = CXXConstructorDecl::Create(
8835      Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/0,
8836      /*isExplicit=*/false, /*isInline=*/true, /*isImplicitlyDeclared=*/true,
8837      Constexpr);
8838  MoveConstructor->setAccess(AS_public);
8839  MoveConstructor->setDefaulted();
8840  MoveConstructor->setTrivial(ClassDecl->hasTrivialMoveConstructor());
8841
8842  // Build an exception specification pointing back at this member.
8843  FunctionProtoType::ExtProtoInfo EPI;
8844  EPI.ExceptionSpecType = EST_Unevaluated;
8845  EPI.ExceptionSpecDecl = MoveConstructor;
8846  MoveConstructor->setType(
8847      Context.getFunctionType(Context.VoidTy, &ArgType, 1, EPI));
8848
8849  // Add the parameter to the constructor.
8850  ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveConstructor,
8851                                               ClassLoc, ClassLoc,
8852                                               /*IdentifierInfo=*/0,
8853                                               ArgType, /*TInfo=*/0,
8854                                               SC_None,
8855                                               SC_None, 0);
8856  MoveConstructor->setParams(FromParam);
8857
8858  // C++0x [class.copy]p9:
8859  //   If the definition of a class X does not explicitly declare a move
8860  //   constructor, one will be implicitly declared as defaulted if and only if:
8861  //   [...]
8862  //   - the move constructor would not be implicitly defined as deleted.
8863  if (ShouldDeleteSpecialMember(MoveConstructor, CXXMoveConstructor)) {
8864    // Cache this result so that we don't try to generate this over and over
8865    // on every lookup, leaking memory and wasting time.
8866    ClassDecl->setFailedImplicitMoveConstructor();
8867    return 0;
8868  }
8869
8870  // Note that we have declared this constructor.
8871  ++ASTContext::NumImplicitMoveConstructorsDeclared;
8872
8873  if (Scope *S = getScopeForContext(ClassDecl))
8874    PushOnScopeChains(MoveConstructor, S, false);
8875  ClassDecl->addDecl(MoveConstructor);
8876
8877  return MoveConstructor;
8878}
8879
8880void Sema::DefineImplicitMoveConstructor(SourceLocation CurrentLocation,
8881                                   CXXConstructorDecl *MoveConstructor) {
8882  assert((MoveConstructor->isDefaulted() &&
8883          MoveConstructor->isMoveConstructor() &&
8884          !MoveConstructor->doesThisDeclarationHaveABody() &&
8885          !MoveConstructor->isDeleted()) &&
8886         "DefineImplicitMoveConstructor - call it for implicit move ctor");
8887
8888  CXXRecordDecl *ClassDecl = MoveConstructor->getParent();
8889  assert(ClassDecl && "DefineImplicitMoveConstructor - invalid constructor");
8890
8891  ImplicitlyDefinedFunctionScope Scope(*this, MoveConstructor);
8892  DiagnosticErrorTrap Trap(Diags);
8893
8894  if (SetCtorInitializers(MoveConstructor, 0, 0, /*AnyErrors=*/false) ||
8895      Trap.hasErrorOccurred()) {
8896    Diag(CurrentLocation, diag::note_member_synthesized_at)
8897      << CXXMoveConstructor << Context.getTagDeclType(ClassDecl);
8898    MoveConstructor->setInvalidDecl();
8899  }  else {
8900    Sema::CompoundScopeRAII CompoundScope(*this);
8901    MoveConstructor->setBody(ActOnCompoundStmt(MoveConstructor->getLocation(),
8902                                               MoveConstructor->getLocation(),
8903                                               MultiStmtArg(*this, 0, 0),
8904                                               /*isStmtExpr=*/false)
8905                                                              .takeAs<Stmt>());
8906    MoveConstructor->setImplicitlyDefined(true);
8907  }
8908
8909  MoveConstructor->setUsed();
8910
8911  if (ASTMutationListener *L = getASTMutationListener()) {
8912    L->CompletedImplicitDefinition(MoveConstructor);
8913  }
8914}
8915
8916bool Sema::isImplicitlyDeleted(FunctionDecl *FD) {
8917  return FD->isDeleted() &&
8918         (FD->isDefaulted() || FD->isImplicit()) &&
8919         isa<CXXMethodDecl>(FD);
8920}
8921
8922/// \brief Mark the call operator of the given lambda closure type as "used".
8923static void markLambdaCallOperatorUsed(Sema &S, CXXRecordDecl *Lambda) {
8924  CXXMethodDecl *CallOperator
8925    = cast<CXXMethodDecl>(
8926        *Lambda->lookup(
8927          S.Context.DeclarationNames.getCXXOperatorName(OO_Call)).first);
8928  CallOperator->setReferenced();
8929  CallOperator->setUsed();
8930}
8931
8932void Sema::DefineImplicitLambdaToFunctionPointerConversion(
8933       SourceLocation CurrentLocation,
8934       CXXConversionDecl *Conv)
8935{
8936  CXXRecordDecl *Lambda = Conv->getParent();
8937
8938  // Make sure that the lambda call operator is marked used.
8939  markLambdaCallOperatorUsed(*this, Lambda);
8940
8941  Conv->setUsed();
8942
8943  ImplicitlyDefinedFunctionScope Scope(*this, Conv);
8944  DiagnosticErrorTrap Trap(Diags);
8945
8946  // Return the address of the __invoke function.
8947  DeclarationName InvokeName = &Context.Idents.get("__invoke");
8948  CXXMethodDecl *Invoke
8949    = cast<CXXMethodDecl>(*Lambda->lookup(InvokeName).first);
8950  Expr *FunctionRef = BuildDeclRefExpr(Invoke, Invoke->getType(),
8951                                       VK_LValue, Conv->getLocation()).take();
8952  assert(FunctionRef && "Can't refer to __invoke function?");
8953  Stmt *Return = ActOnReturnStmt(Conv->getLocation(), FunctionRef).take();
8954  Conv->setBody(new (Context) CompoundStmt(Context, &Return, 1,
8955                                           Conv->getLocation(),
8956                                           Conv->getLocation()));
8957
8958  // Fill in the __invoke function with a dummy implementation. IR generation
8959  // will fill in the actual details.
8960  Invoke->setUsed();
8961  Invoke->setReferenced();
8962  Invoke->setBody(new (Context) CompoundStmt(Conv->getLocation()));
8963
8964  if (ASTMutationListener *L = getASTMutationListener()) {
8965    L->CompletedImplicitDefinition(Conv);
8966    L->CompletedImplicitDefinition(Invoke);
8967  }
8968}
8969
8970void Sema::DefineImplicitLambdaToBlockPointerConversion(
8971       SourceLocation CurrentLocation,
8972       CXXConversionDecl *Conv)
8973{
8974  Conv->setUsed();
8975
8976  ImplicitlyDefinedFunctionScope Scope(*this, Conv);
8977  DiagnosticErrorTrap Trap(Diags);
8978
8979  // Copy-initialize the lambda object as needed to capture it.
8980  Expr *This = ActOnCXXThis(CurrentLocation).take();
8981  Expr *DerefThis =CreateBuiltinUnaryOp(CurrentLocation, UO_Deref, This).take();
8982
8983  ExprResult BuildBlock = BuildBlockForLambdaConversion(CurrentLocation,
8984                                                        Conv->getLocation(),
8985                                                        Conv, DerefThis);
8986
8987  // If we're not under ARC, make sure we still get the _Block_copy/autorelease
8988  // behavior.  Note that only the general conversion function does this
8989  // (since it's unusable otherwise); in the case where we inline the
8990  // block literal, it has block literal lifetime semantics.
8991  if (!BuildBlock.isInvalid() && !getLangOpts().ObjCAutoRefCount)
8992    BuildBlock = ImplicitCastExpr::Create(Context, BuildBlock.get()->getType(),
8993                                          CK_CopyAndAutoreleaseBlockObject,
8994                                          BuildBlock.get(), 0, VK_RValue);
8995
8996  if (BuildBlock.isInvalid()) {
8997    Diag(CurrentLocation, diag::note_lambda_to_block_conv);
8998    Conv->setInvalidDecl();
8999    return;
9000  }
9001
9002  // Create the return statement that returns the block from the conversion
9003  // function.
9004  StmtResult Return = ActOnReturnStmt(Conv->getLocation(), BuildBlock.get());
9005  if (Return.isInvalid()) {
9006    Diag(CurrentLocation, diag::note_lambda_to_block_conv);
9007    Conv->setInvalidDecl();
9008    return;
9009  }
9010
9011  // Set the body of the conversion function.
9012  Stmt *ReturnS = Return.take();
9013  Conv->setBody(new (Context) CompoundStmt(Context, &ReturnS, 1,
9014                                           Conv->getLocation(),
9015                                           Conv->getLocation()));
9016
9017  // We're done; notify the mutation listener, if any.
9018  if (ASTMutationListener *L = getASTMutationListener()) {
9019    L->CompletedImplicitDefinition(Conv);
9020  }
9021}
9022
9023/// \brief Determine whether the given list arguments contains exactly one
9024/// "real" (non-default) argument.
9025static bool hasOneRealArgument(MultiExprArg Args) {
9026  switch (Args.size()) {
9027  case 0:
9028    return false;
9029
9030  default:
9031    if (!Args.get()[1]->isDefaultArgument())
9032      return false;
9033
9034    // fall through
9035  case 1:
9036    return !Args.get()[0]->isDefaultArgument();
9037  }
9038
9039  return false;
9040}
9041
9042ExprResult
9043Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
9044                            CXXConstructorDecl *Constructor,
9045                            MultiExprArg ExprArgs,
9046                            bool HadMultipleCandidates,
9047                            bool RequiresZeroInit,
9048                            unsigned ConstructKind,
9049                            SourceRange ParenRange) {
9050  bool Elidable = false;
9051
9052  // C++0x [class.copy]p34:
9053  //   When certain criteria are met, an implementation is allowed to
9054  //   omit the copy/move construction of a class object, even if the
9055  //   copy/move constructor and/or destructor for the object have
9056  //   side effects. [...]
9057  //     - when a temporary class object that has not been bound to a
9058  //       reference (12.2) would be copied/moved to a class object
9059  //       with the same cv-unqualified type, the copy/move operation
9060  //       can be omitted by constructing the temporary object
9061  //       directly into the target of the omitted copy/move
9062  if (ConstructKind == CXXConstructExpr::CK_Complete &&
9063      Constructor->isCopyOrMoveConstructor() && hasOneRealArgument(ExprArgs)) {
9064    Expr *SubExpr = ((Expr **)ExprArgs.get())[0];
9065    Elidable = SubExpr->isTemporaryObject(Context, Constructor->getParent());
9066  }
9067
9068  return BuildCXXConstructExpr(ConstructLoc, DeclInitType, Constructor,
9069                               Elidable, move(ExprArgs), HadMultipleCandidates,
9070                               RequiresZeroInit, ConstructKind, ParenRange);
9071}
9072
9073/// BuildCXXConstructExpr - Creates a complete call to a constructor,
9074/// including handling of its default argument expressions.
9075ExprResult
9076Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
9077                            CXXConstructorDecl *Constructor, bool Elidable,
9078                            MultiExprArg ExprArgs,
9079                            bool HadMultipleCandidates,
9080                            bool RequiresZeroInit,
9081                            unsigned ConstructKind,
9082                            SourceRange ParenRange) {
9083  unsigned NumExprs = ExprArgs.size();
9084  Expr **Exprs = (Expr **)ExprArgs.release();
9085
9086  MarkFunctionReferenced(ConstructLoc, Constructor);
9087  return Owned(CXXConstructExpr::Create(Context, DeclInitType, ConstructLoc,
9088                                        Constructor, Elidable, Exprs, NumExprs,
9089                                        HadMultipleCandidates, /*FIXME*/false,
9090                                        RequiresZeroInit,
9091              static_cast<CXXConstructExpr::ConstructionKind>(ConstructKind),
9092                                        ParenRange));
9093}
9094
9095bool Sema::InitializeVarWithConstructor(VarDecl *VD,
9096                                        CXXConstructorDecl *Constructor,
9097                                        MultiExprArg Exprs,
9098                                        bool HadMultipleCandidates) {
9099  // FIXME: Provide the correct paren SourceRange when available.
9100  ExprResult TempResult =
9101    BuildCXXConstructExpr(VD->getLocation(), VD->getType(), Constructor,
9102                          move(Exprs), HadMultipleCandidates, false,
9103                          CXXConstructExpr::CK_Complete, SourceRange());
9104  if (TempResult.isInvalid())
9105    return true;
9106
9107  Expr *Temp = TempResult.takeAs<Expr>();
9108  CheckImplicitConversions(Temp, VD->getLocation());
9109  MarkFunctionReferenced(VD->getLocation(), Constructor);
9110  Temp = MaybeCreateExprWithCleanups(Temp);
9111  VD->setInit(Temp);
9112
9113  return false;
9114}
9115
9116void Sema::FinalizeVarWithDestructor(VarDecl *VD, const RecordType *Record) {
9117  if (VD->isInvalidDecl()) return;
9118
9119  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Record->getDecl());
9120  if (ClassDecl->isInvalidDecl()) return;
9121  if (ClassDecl->hasIrrelevantDestructor()) return;
9122  if (ClassDecl->isDependentContext()) return;
9123
9124  CXXDestructorDecl *Destructor = LookupDestructor(ClassDecl);
9125  MarkFunctionReferenced(VD->getLocation(), Destructor);
9126  CheckDestructorAccess(VD->getLocation(), Destructor,
9127                        PDiag(diag::err_access_dtor_var)
9128                        << VD->getDeclName()
9129                        << VD->getType());
9130  DiagnoseUseOfDecl(Destructor, VD->getLocation());
9131
9132  if (!VD->hasGlobalStorage()) return;
9133
9134  // Emit warning for non-trivial dtor in global scope (a real global,
9135  // class-static, function-static).
9136  Diag(VD->getLocation(), diag::warn_exit_time_destructor);
9137
9138  // TODO: this should be re-enabled for static locals by !CXAAtExit
9139  if (!VD->isStaticLocal())
9140    Diag(VD->getLocation(), diag::warn_global_destructor);
9141}
9142
9143/// \brief Given a constructor and the set of arguments provided for the
9144/// constructor, convert the arguments and add any required default arguments
9145/// to form a proper call to this constructor.
9146///
9147/// \returns true if an error occurred, false otherwise.
9148bool
9149Sema::CompleteConstructorCall(CXXConstructorDecl *Constructor,
9150                              MultiExprArg ArgsPtr,
9151                              SourceLocation Loc,
9152                              ASTOwningVector<Expr*> &ConvertedArgs,
9153                              bool AllowExplicit) {
9154  // FIXME: This duplicates a lot of code from Sema::ConvertArgumentsForCall.
9155  unsigned NumArgs = ArgsPtr.size();
9156  Expr **Args = (Expr **)ArgsPtr.get();
9157
9158  const FunctionProtoType *Proto
9159    = Constructor->getType()->getAs<FunctionProtoType>();
9160  assert(Proto && "Constructor without a prototype?");
9161  unsigned NumArgsInProto = Proto->getNumArgs();
9162
9163  // If too few arguments are available, we'll fill in the rest with defaults.
9164  if (NumArgs < NumArgsInProto)
9165    ConvertedArgs.reserve(NumArgsInProto);
9166  else
9167    ConvertedArgs.reserve(NumArgs);
9168
9169  VariadicCallType CallType =
9170    Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
9171  SmallVector<Expr *, 8> AllArgs;
9172  bool Invalid = GatherArgumentsForCall(Loc, Constructor,
9173                                        Proto, 0, Args, NumArgs, AllArgs,
9174                                        CallType, AllowExplicit);
9175  ConvertedArgs.append(AllArgs.begin(), AllArgs.end());
9176
9177  DiagnoseSentinelCalls(Constructor, Loc, AllArgs.data(), AllArgs.size());
9178
9179  CheckConstructorCall(Constructor, AllArgs.data(), AllArgs.size(),
9180                       Proto, Loc);
9181
9182  return Invalid;
9183}
9184
9185static inline bool
9186CheckOperatorNewDeleteDeclarationScope(Sema &SemaRef,
9187                                       const FunctionDecl *FnDecl) {
9188  const DeclContext *DC = FnDecl->getDeclContext()->getRedeclContext();
9189  if (isa<NamespaceDecl>(DC)) {
9190    return SemaRef.Diag(FnDecl->getLocation(),
9191                        diag::err_operator_new_delete_declared_in_namespace)
9192      << FnDecl->getDeclName();
9193  }
9194
9195  if (isa<TranslationUnitDecl>(DC) &&
9196      FnDecl->getStorageClass() == SC_Static) {
9197    return SemaRef.Diag(FnDecl->getLocation(),
9198                        diag::err_operator_new_delete_declared_static)
9199      << FnDecl->getDeclName();
9200  }
9201
9202  return false;
9203}
9204
9205static inline bool
9206CheckOperatorNewDeleteTypes(Sema &SemaRef, const FunctionDecl *FnDecl,
9207                            CanQualType ExpectedResultType,
9208                            CanQualType ExpectedFirstParamType,
9209                            unsigned DependentParamTypeDiag,
9210                            unsigned InvalidParamTypeDiag) {
9211  QualType ResultType =
9212    FnDecl->getType()->getAs<FunctionType>()->getResultType();
9213
9214  // Check that the result type is not dependent.
9215  if (ResultType->isDependentType())
9216    return SemaRef.Diag(FnDecl->getLocation(),
9217                        diag::err_operator_new_delete_dependent_result_type)
9218    << FnDecl->getDeclName() << ExpectedResultType;
9219
9220  // Check that the result type is what we expect.
9221  if (SemaRef.Context.getCanonicalType(ResultType) != ExpectedResultType)
9222    return SemaRef.Diag(FnDecl->getLocation(),
9223                        diag::err_operator_new_delete_invalid_result_type)
9224    << FnDecl->getDeclName() << ExpectedResultType;
9225
9226  // A function template must have at least 2 parameters.
9227  if (FnDecl->getDescribedFunctionTemplate() && FnDecl->getNumParams() < 2)
9228    return SemaRef.Diag(FnDecl->getLocation(),
9229                      diag::err_operator_new_delete_template_too_few_parameters)
9230        << FnDecl->getDeclName();
9231
9232  // The function decl must have at least 1 parameter.
9233  if (FnDecl->getNumParams() == 0)
9234    return SemaRef.Diag(FnDecl->getLocation(),
9235                        diag::err_operator_new_delete_too_few_parameters)
9236      << FnDecl->getDeclName();
9237
9238  // Check the first parameter type is not dependent.
9239  QualType FirstParamType = FnDecl->getParamDecl(0)->getType();
9240  if (FirstParamType->isDependentType())
9241    return SemaRef.Diag(FnDecl->getLocation(), DependentParamTypeDiag)
9242      << FnDecl->getDeclName() << ExpectedFirstParamType;
9243
9244  // Check that the first parameter type is what we expect.
9245  if (SemaRef.Context.getCanonicalType(FirstParamType).getUnqualifiedType() !=
9246      ExpectedFirstParamType)
9247    return SemaRef.Diag(FnDecl->getLocation(), InvalidParamTypeDiag)
9248    << FnDecl->getDeclName() << ExpectedFirstParamType;
9249
9250  return false;
9251}
9252
9253static bool
9254CheckOperatorNewDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
9255  // C++ [basic.stc.dynamic.allocation]p1:
9256  //   A program is ill-formed if an allocation function is declared in a
9257  //   namespace scope other than global scope or declared static in global
9258  //   scope.
9259  if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
9260    return true;
9261
9262  CanQualType SizeTy =
9263    SemaRef.Context.getCanonicalType(SemaRef.Context.getSizeType());
9264
9265  // C++ [basic.stc.dynamic.allocation]p1:
9266  //  The return type shall be void*. The first parameter shall have type
9267  //  std::size_t.
9268  if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidPtrTy,
9269                                  SizeTy,
9270                                  diag::err_operator_new_dependent_param_type,
9271                                  diag::err_operator_new_param_type))
9272    return true;
9273
9274  // C++ [basic.stc.dynamic.allocation]p1:
9275  //  The first parameter shall not have an associated default argument.
9276  if (FnDecl->getParamDecl(0)->hasDefaultArg())
9277    return SemaRef.Diag(FnDecl->getLocation(),
9278                        diag::err_operator_new_default_arg)
9279      << FnDecl->getDeclName() << FnDecl->getParamDecl(0)->getDefaultArgRange();
9280
9281  return false;
9282}
9283
9284static bool
9285CheckOperatorDeleteDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
9286  // C++ [basic.stc.dynamic.deallocation]p1:
9287  //   A program is ill-formed if deallocation functions are declared in a
9288  //   namespace scope other than global scope or declared static in global
9289  //   scope.
9290  if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
9291    return true;
9292
9293  // C++ [basic.stc.dynamic.deallocation]p2:
9294  //   Each deallocation function shall return void and its first parameter
9295  //   shall be void*.
9296  if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidTy,
9297                                  SemaRef.Context.VoidPtrTy,
9298                                 diag::err_operator_delete_dependent_param_type,
9299                                 diag::err_operator_delete_param_type))
9300    return true;
9301
9302  return false;
9303}
9304
9305/// CheckOverloadedOperatorDeclaration - Check whether the declaration
9306/// of this overloaded operator is well-formed. If so, returns false;
9307/// otherwise, emits appropriate diagnostics and returns true.
9308bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) {
9309  assert(FnDecl && FnDecl->isOverloadedOperator() &&
9310         "Expected an overloaded operator declaration");
9311
9312  OverloadedOperatorKind Op = FnDecl->getOverloadedOperator();
9313
9314  // C++ [over.oper]p5:
9315  //   The allocation and deallocation functions, operator new,
9316  //   operator new[], operator delete and operator delete[], are
9317  //   described completely in 3.7.3. The attributes and restrictions
9318  //   found in the rest of this subclause do not apply to them unless
9319  //   explicitly stated in 3.7.3.
9320  if (Op == OO_Delete || Op == OO_Array_Delete)
9321    return CheckOperatorDeleteDeclaration(*this, FnDecl);
9322
9323  if (Op == OO_New || Op == OO_Array_New)
9324    return CheckOperatorNewDeclaration(*this, FnDecl);
9325
9326  // C++ [over.oper]p6:
9327  //   An operator function shall either be a non-static member
9328  //   function or be a non-member function and have at least one
9329  //   parameter whose type is a class, a reference to a class, an
9330  //   enumeration, or a reference to an enumeration.
9331  if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) {
9332    if (MethodDecl->isStatic())
9333      return Diag(FnDecl->getLocation(),
9334                  diag::err_operator_overload_static) << FnDecl->getDeclName();
9335  } else {
9336    bool ClassOrEnumParam = false;
9337    for (FunctionDecl::param_iterator Param = FnDecl->param_begin(),
9338                                   ParamEnd = FnDecl->param_end();
9339         Param != ParamEnd; ++Param) {
9340      QualType ParamType = (*Param)->getType().getNonReferenceType();
9341      if (ParamType->isDependentType() || ParamType->isRecordType() ||
9342          ParamType->isEnumeralType()) {
9343        ClassOrEnumParam = true;
9344        break;
9345      }
9346    }
9347
9348    if (!ClassOrEnumParam)
9349      return Diag(FnDecl->getLocation(),
9350                  diag::err_operator_overload_needs_class_or_enum)
9351        << FnDecl->getDeclName();
9352  }
9353
9354  // C++ [over.oper]p8:
9355  //   An operator function cannot have default arguments (8.3.6),
9356  //   except where explicitly stated below.
9357  //
9358  // Only the function-call operator allows default arguments
9359  // (C++ [over.call]p1).
9360  if (Op != OO_Call) {
9361    for (FunctionDecl::param_iterator Param = FnDecl->param_begin();
9362         Param != FnDecl->param_end(); ++Param) {
9363      if ((*Param)->hasDefaultArg())
9364        return Diag((*Param)->getLocation(),
9365                    diag::err_operator_overload_default_arg)
9366          << FnDecl->getDeclName() << (*Param)->getDefaultArgRange();
9367    }
9368  }
9369
9370  static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = {
9371    { false, false, false }
9372#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
9373    , { Unary, Binary, MemberOnly }
9374#include "clang/Basic/OperatorKinds.def"
9375  };
9376
9377  bool CanBeUnaryOperator = OperatorUses[Op][0];
9378  bool CanBeBinaryOperator = OperatorUses[Op][1];
9379  bool MustBeMemberOperator = OperatorUses[Op][2];
9380
9381  // C++ [over.oper]p8:
9382  //   [...] Operator functions cannot have more or fewer parameters
9383  //   than the number required for the corresponding operator, as
9384  //   described in the rest of this subclause.
9385  unsigned NumParams = FnDecl->getNumParams()
9386                     + (isa<CXXMethodDecl>(FnDecl)? 1 : 0);
9387  if (Op != OO_Call &&
9388      ((NumParams == 1 && !CanBeUnaryOperator) ||
9389       (NumParams == 2 && !CanBeBinaryOperator) ||
9390       (NumParams < 1) || (NumParams > 2))) {
9391    // We have the wrong number of parameters.
9392    unsigned ErrorKind;
9393    if (CanBeUnaryOperator && CanBeBinaryOperator) {
9394      ErrorKind = 2;  // 2 -> unary or binary.
9395    } else if (CanBeUnaryOperator) {
9396      ErrorKind = 0;  // 0 -> unary
9397    } else {
9398      assert(CanBeBinaryOperator &&
9399             "All non-call overloaded operators are unary or binary!");
9400      ErrorKind = 1;  // 1 -> binary
9401    }
9402
9403    return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be)
9404      << FnDecl->getDeclName() << NumParams << ErrorKind;
9405  }
9406
9407  // Overloaded operators other than operator() cannot be variadic.
9408  if (Op != OO_Call &&
9409      FnDecl->getType()->getAs<FunctionProtoType>()->isVariadic()) {
9410    return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic)
9411      << FnDecl->getDeclName();
9412  }
9413
9414  // Some operators must be non-static member functions.
9415  if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) {
9416    return Diag(FnDecl->getLocation(),
9417                diag::err_operator_overload_must_be_member)
9418      << FnDecl->getDeclName();
9419  }
9420
9421  // C++ [over.inc]p1:
9422  //   The user-defined function called operator++ implements the
9423  //   prefix and postfix ++ operator. If this function is a member
9424  //   function with no parameters, or a non-member function with one
9425  //   parameter of class or enumeration type, it defines the prefix
9426  //   increment operator ++ for objects of that type. If the function
9427  //   is a member function with one parameter (which shall be of type
9428  //   int) or a non-member function with two parameters (the second
9429  //   of which shall be of type int), it defines the postfix
9430  //   increment operator ++ for objects of that type.
9431  if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) {
9432    ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1);
9433    bool ParamIsInt = false;
9434    if (const BuiltinType *BT = LastParam->getType()->getAs<BuiltinType>())
9435      ParamIsInt = BT->getKind() == BuiltinType::Int;
9436
9437    if (!ParamIsInt)
9438      return Diag(LastParam->getLocation(),
9439                  diag::err_operator_overload_post_incdec_must_be_int)
9440        << LastParam->getType() << (Op == OO_MinusMinus);
9441  }
9442
9443  return false;
9444}
9445
9446/// CheckLiteralOperatorDeclaration - Check whether the declaration
9447/// of this literal operator function is well-formed. If so, returns
9448/// false; otherwise, emits appropriate diagnostics and returns true.
9449bool Sema::CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl) {
9450  if (isa<CXXMethodDecl>(FnDecl)) {
9451    Diag(FnDecl->getLocation(), diag::err_literal_operator_outside_namespace)
9452      << FnDecl->getDeclName();
9453    return true;
9454  }
9455
9456  if (FnDecl->isExternC()) {
9457    Diag(FnDecl->getLocation(), diag::err_literal_operator_extern_c);
9458    return true;
9459  }
9460
9461  bool Valid = false;
9462
9463  // This might be the definition of a literal operator template.
9464  FunctionTemplateDecl *TpDecl = FnDecl->getDescribedFunctionTemplate();
9465  // This might be a specialization of a literal operator template.
9466  if (!TpDecl)
9467    TpDecl = FnDecl->getPrimaryTemplate();
9468
9469  // template <char...> type operator "" name() is the only valid template
9470  // signature, and the only valid signature with no parameters.
9471  if (TpDecl) {
9472    if (FnDecl->param_size() == 0) {
9473      // Must have only one template parameter
9474      TemplateParameterList *Params = TpDecl->getTemplateParameters();
9475      if (Params->size() == 1) {
9476        NonTypeTemplateParmDecl *PmDecl =
9477          dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(0));
9478
9479        // The template parameter must be a char parameter pack.
9480        if (PmDecl && PmDecl->isTemplateParameterPack() &&
9481            Context.hasSameType(PmDecl->getType(), Context.CharTy))
9482          Valid = true;
9483      }
9484    }
9485  } else if (FnDecl->param_size()) {
9486    // Check the first parameter
9487    FunctionDecl::param_iterator Param = FnDecl->param_begin();
9488
9489    QualType T = (*Param)->getType().getUnqualifiedType();
9490
9491    // unsigned long long int, long double, and any character type are allowed
9492    // as the only parameters.
9493    if (Context.hasSameType(T, Context.UnsignedLongLongTy) ||
9494        Context.hasSameType(T, Context.LongDoubleTy) ||
9495        Context.hasSameType(T, Context.CharTy) ||
9496        Context.hasSameType(T, Context.WCharTy) ||
9497        Context.hasSameType(T, Context.Char16Ty) ||
9498        Context.hasSameType(T, Context.Char32Ty)) {
9499      if (++Param == FnDecl->param_end())
9500        Valid = true;
9501      goto FinishedParams;
9502    }
9503
9504    // Otherwise it must be a pointer to const; let's strip those qualifiers.
9505    const PointerType *PT = T->getAs<PointerType>();
9506    if (!PT)
9507      goto FinishedParams;
9508    T = PT->getPointeeType();
9509    if (!T.isConstQualified() || T.isVolatileQualified())
9510      goto FinishedParams;
9511    T = T.getUnqualifiedType();
9512
9513    // Move on to the second parameter;
9514    ++Param;
9515
9516    // If there is no second parameter, the first must be a const char *
9517    if (Param == FnDecl->param_end()) {
9518      if (Context.hasSameType(T, Context.CharTy))
9519        Valid = true;
9520      goto FinishedParams;
9521    }
9522
9523    // const char *, const wchar_t*, const char16_t*, and const char32_t*
9524    // are allowed as the first parameter to a two-parameter function
9525    if (!(Context.hasSameType(T, Context.CharTy) ||
9526          Context.hasSameType(T, Context.WCharTy) ||
9527          Context.hasSameType(T, Context.Char16Ty) ||
9528          Context.hasSameType(T, Context.Char32Ty)))
9529      goto FinishedParams;
9530
9531    // The second and final parameter must be an std::size_t
9532    T = (*Param)->getType().getUnqualifiedType();
9533    if (Context.hasSameType(T, Context.getSizeType()) &&
9534        ++Param == FnDecl->param_end())
9535      Valid = true;
9536  }
9537
9538  // FIXME: This diagnostic is absolutely terrible.
9539FinishedParams:
9540  if (!Valid) {
9541    Diag(FnDecl->getLocation(), diag::err_literal_operator_params)
9542      << FnDecl->getDeclName();
9543    return true;
9544  }
9545
9546  // A parameter-declaration-clause containing a default argument is not
9547  // equivalent to any of the permitted forms.
9548  for (FunctionDecl::param_iterator Param = FnDecl->param_begin(),
9549                                    ParamEnd = FnDecl->param_end();
9550       Param != ParamEnd; ++Param) {
9551    if ((*Param)->hasDefaultArg()) {
9552      Diag((*Param)->getDefaultArgRange().getBegin(),
9553           diag::err_literal_operator_default_argument)
9554        << (*Param)->getDefaultArgRange();
9555      break;
9556    }
9557  }
9558
9559  StringRef LiteralName
9560    = FnDecl->getDeclName().getCXXLiteralIdentifier()->getName();
9561  if (LiteralName[0] != '_') {
9562    // C++11 [usrlit.suffix]p1:
9563    //   Literal suffix identifiers that do not start with an underscore
9564    //   are reserved for future standardization.
9565    Diag(FnDecl->getLocation(), diag::warn_user_literal_reserved);
9566  }
9567
9568  return false;
9569}
9570
9571/// ActOnStartLinkageSpecification - Parsed the beginning of a C++
9572/// linkage specification, including the language and (if present)
9573/// the '{'. ExternLoc is the location of the 'extern', LangLoc is
9574/// the location of the language string literal, which is provided
9575/// by Lang/StrSize. LBraceLoc, if valid, provides the location of
9576/// the '{' brace. Otherwise, this linkage specification does not
9577/// have any braces.
9578Decl *Sema::ActOnStartLinkageSpecification(Scope *S, SourceLocation ExternLoc,
9579                                           SourceLocation LangLoc,
9580                                           StringRef Lang,
9581                                           SourceLocation LBraceLoc) {
9582  LinkageSpecDecl::LanguageIDs Language;
9583  if (Lang == "\"C\"")
9584    Language = LinkageSpecDecl::lang_c;
9585  else if (Lang == "\"C++\"")
9586    Language = LinkageSpecDecl::lang_cxx;
9587  else {
9588    Diag(LangLoc, diag::err_bad_language);
9589    return 0;
9590  }
9591
9592  // FIXME: Add all the various semantics of linkage specifications
9593
9594  LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext,
9595                                               ExternLoc, LangLoc, Language);
9596  CurContext->addDecl(D);
9597  PushDeclContext(S, D);
9598  return D;
9599}
9600
9601/// ActOnFinishLinkageSpecification - Complete the definition of
9602/// the C++ linkage specification LinkageSpec. If RBraceLoc is
9603/// valid, it's the position of the closing '}' brace in a linkage
9604/// specification that uses braces.
9605Decl *Sema::ActOnFinishLinkageSpecification(Scope *S,
9606                                            Decl *LinkageSpec,
9607                                            SourceLocation RBraceLoc) {
9608  if (LinkageSpec) {
9609    if (RBraceLoc.isValid()) {
9610      LinkageSpecDecl* LSDecl = cast<LinkageSpecDecl>(LinkageSpec);
9611      LSDecl->setRBraceLoc(RBraceLoc);
9612    }
9613    PopDeclContext();
9614  }
9615  return LinkageSpec;
9616}
9617
9618/// \brief Perform semantic analysis for the variable declaration that
9619/// occurs within a C++ catch clause, returning the newly-created
9620/// variable.
9621VarDecl *Sema::BuildExceptionDeclaration(Scope *S,
9622                                         TypeSourceInfo *TInfo,
9623                                         SourceLocation StartLoc,
9624                                         SourceLocation Loc,
9625                                         IdentifierInfo *Name) {
9626  bool Invalid = false;
9627  QualType ExDeclType = TInfo->getType();
9628
9629  // Arrays and functions decay.
9630  if (ExDeclType->isArrayType())
9631    ExDeclType = Context.getArrayDecayedType(ExDeclType);
9632  else if (ExDeclType->isFunctionType())
9633    ExDeclType = Context.getPointerType(ExDeclType);
9634
9635  // C++ 15.3p1: The exception-declaration shall not denote an incomplete type.
9636  // The exception-declaration shall not denote a pointer or reference to an
9637  // incomplete type, other than [cv] void*.
9638  // N2844 forbids rvalue references.
9639  if (!ExDeclType->isDependentType() && ExDeclType->isRValueReferenceType()) {
9640    Diag(Loc, diag::err_catch_rvalue_ref);
9641    Invalid = true;
9642  }
9643
9644  QualType BaseType = ExDeclType;
9645  int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference
9646  unsigned DK = diag::err_catch_incomplete;
9647  if (const PointerType *Ptr = BaseType->getAs<PointerType>()) {
9648    BaseType = Ptr->getPointeeType();
9649    Mode = 1;
9650    DK = diag::err_catch_incomplete_ptr;
9651  } else if (const ReferenceType *Ref = BaseType->getAs<ReferenceType>()) {
9652    // For the purpose of error recovery, we treat rvalue refs like lvalue refs.
9653    BaseType = Ref->getPointeeType();
9654    Mode = 2;
9655    DK = diag::err_catch_incomplete_ref;
9656  }
9657  if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) &&
9658      !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK))
9659    Invalid = true;
9660
9661  if (!Invalid && !ExDeclType->isDependentType() &&
9662      RequireNonAbstractType(Loc, ExDeclType,
9663                             diag::err_abstract_type_in_decl,
9664                             AbstractVariableType))
9665    Invalid = true;
9666
9667  // Only the non-fragile NeXT runtime currently supports C++ catches
9668  // of ObjC types, and no runtime supports catching ObjC types by value.
9669  if (!Invalid && getLangOpts().ObjC1) {
9670    QualType T = ExDeclType;
9671    if (const ReferenceType *RT = T->getAs<ReferenceType>())
9672      T = RT->getPointeeType();
9673
9674    if (T->isObjCObjectType()) {
9675      Diag(Loc, diag::err_objc_object_catch);
9676      Invalid = true;
9677    } else if (T->isObjCObjectPointerType()) {
9678      // FIXME: should this be a test for macosx-fragile specifically?
9679      if (getLangOpts().ObjCRuntime.isFragile())
9680        Diag(Loc, diag::warn_objc_pointer_cxx_catch_fragile);
9681    }
9682  }
9683
9684  VarDecl *ExDecl = VarDecl::Create(Context, CurContext, StartLoc, Loc, Name,
9685                                    ExDeclType, TInfo, SC_None, SC_None);
9686  ExDecl->setExceptionVariable(true);
9687
9688  // In ARC, infer 'retaining' for variables of retainable type.
9689  if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(ExDecl))
9690    Invalid = true;
9691
9692  if (!Invalid && !ExDeclType->isDependentType()) {
9693    if (const RecordType *recordType = ExDeclType->getAs<RecordType>()) {
9694      // C++ [except.handle]p16:
9695      //   The object declared in an exception-declaration or, if the
9696      //   exception-declaration does not specify a name, a temporary (12.2) is
9697      //   copy-initialized (8.5) from the exception object. [...]
9698      //   The object is destroyed when the handler exits, after the destruction
9699      //   of any automatic objects initialized within the handler.
9700      //
9701      // We just pretend to initialize the object with itself, then make sure
9702      // it can be destroyed later.
9703      QualType initType = ExDeclType;
9704
9705      InitializedEntity entity =
9706        InitializedEntity::InitializeVariable(ExDecl);
9707      InitializationKind initKind =
9708        InitializationKind::CreateCopy(Loc, SourceLocation());
9709
9710      Expr *opaqueValue =
9711        new (Context) OpaqueValueExpr(Loc, initType, VK_LValue, OK_Ordinary);
9712      InitializationSequence sequence(*this, entity, initKind, &opaqueValue, 1);
9713      ExprResult result = sequence.Perform(*this, entity, initKind,
9714                                           MultiExprArg(&opaqueValue, 1));
9715      if (result.isInvalid())
9716        Invalid = true;
9717      else {
9718        // If the constructor used was non-trivial, set this as the
9719        // "initializer".
9720        CXXConstructExpr *construct = cast<CXXConstructExpr>(result.take());
9721        if (!construct->getConstructor()->isTrivial()) {
9722          Expr *init = MaybeCreateExprWithCleanups(construct);
9723          ExDecl->setInit(init);
9724        }
9725
9726        // And make sure it's destructable.
9727        FinalizeVarWithDestructor(ExDecl, recordType);
9728      }
9729    }
9730  }
9731
9732  if (Invalid)
9733    ExDecl->setInvalidDecl();
9734
9735  return ExDecl;
9736}
9737
9738/// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch
9739/// handler.
9740Decl *Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D) {
9741  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
9742  bool Invalid = D.isInvalidType();
9743
9744  // Check for unexpanded parameter packs.
9745  if (TInfo && DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
9746                                               UPPC_ExceptionType)) {
9747    TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
9748                                             D.getIdentifierLoc());
9749    Invalid = true;
9750  }
9751
9752  IdentifierInfo *II = D.getIdentifier();
9753  if (NamedDecl *PrevDecl = LookupSingleName(S, II, D.getIdentifierLoc(),
9754                                             LookupOrdinaryName,
9755                                             ForRedeclaration)) {
9756    // The scope should be freshly made just for us. There is just no way
9757    // it contains any previous declaration.
9758    assert(!S->isDeclScope(PrevDecl));
9759    if (PrevDecl->isTemplateParameter()) {
9760      // Maybe we will complain about the shadowed template parameter.
9761      DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
9762      PrevDecl = 0;
9763    }
9764  }
9765
9766  if (D.getCXXScopeSpec().isSet() && !Invalid) {
9767    Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator)
9768      << D.getCXXScopeSpec().getRange();
9769    Invalid = true;
9770  }
9771
9772  VarDecl *ExDecl = BuildExceptionDeclaration(S, TInfo,
9773                                              D.getLocStart(),
9774                                              D.getIdentifierLoc(),
9775                                              D.getIdentifier());
9776  if (Invalid)
9777    ExDecl->setInvalidDecl();
9778
9779  // Add the exception declaration into this scope.
9780  if (II)
9781    PushOnScopeChains(ExDecl, S);
9782  else
9783    CurContext->addDecl(ExDecl);
9784
9785  ProcessDeclAttributes(S, ExDecl, D);
9786  return ExDecl;
9787}
9788
9789Decl *Sema::ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,
9790                                         Expr *AssertExpr,
9791                                         Expr *AssertMessageExpr,
9792                                         SourceLocation RParenLoc) {
9793  StringLiteral *AssertMessage = cast<StringLiteral>(AssertMessageExpr);
9794
9795  if (DiagnoseUnexpandedParameterPack(AssertExpr, UPPC_StaticAssertExpression))
9796    return 0;
9797
9798  return BuildStaticAssertDeclaration(StaticAssertLoc, AssertExpr,
9799                                      AssertMessage, RParenLoc, false);
9800}
9801
9802Decl *Sema::BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc,
9803                                         Expr *AssertExpr,
9804                                         StringLiteral *AssertMessage,
9805                                         SourceLocation RParenLoc,
9806                                         bool Failed) {
9807  if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent() &&
9808      !Failed) {
9809    // In a static_assert-declaration, the constant-expression shall be a
9810    // constant expression that can be contextually converted to bool.
9811    ExprResult Converted = PerformContextuallyConvertToBool(AssertExpr);
9812    if (Converted.isInvalid())
9813      Failed = true;
9814
9815    llvm::APSInt Cond;
9816    if (!Failed && VerifyIntegerConstantExpression(Converted.get(), &Cond,
9817          diag::err_static_assert_expression_is_not_constant,
9818          /*AllowFold=*/false).isInvalid())
9819      Failed = true;
9820
9821    if (!Failed && !Cond) {
9822      llvm::SmallString<256> MsgBuffer;
9823      llvm::raw_svector_ostream Msg(MsgBuffer);
9824      AssertMessage->printPretty(Msg, Context, 0, getPrintingPolicy());
9825      Diag(StaticAssertLoc, diag::err_static_assert_failed)
9826        << Msg.str() << AssertExpr->getSourceRange();
9827      Failed = true;
9828    }
9829  }
9830
9831  Decl *Decl = StaticAssertDecl::Create(Context, CurContext, StaticAssertLoc,
9832                                        AssertExpr, AssertMessage, RParenLoc,
9833                                        Failed);
9834
9835  CurContext->addDecl(Decl);
9836  return Decl;
9837}
9838
9839/// \brief Perform semantic analysis of the given friend type declaration.
9840///
9841/// \returns A friend declaration that.
9842FriendDecl *Sema::CheckFriendTypeDecl(SourceLocation Loc,
9843                                      SourceLocation FriendLoc,
9844                                      TypeSourceInfo *TSInfo) {
9845  assert(TSInfo && "NULL TypeSourceInfo for friend type declaration");
9846
9847  QualType T = TSInfo->getType();
9848  SourceRange TypeRange = TSInfo->getTypeLoc().getLocalSourceRange();
9849
9850  // C++03 [class.friend]p2:
9851  //   An elaborated-type-specifier shall be used in a friend declaration
9852  //   for a class.*
9853  //
9854  //   * The class-key of the elaborated-type-specifier is required.
9855  if (!ActiveTemplateInstantiations.empty()) {
9856    // Do not complain about the form of friend template types during
9857    // template instantiation; we will already have complained when the
9858    // template was declared.
9859  } else if (!T->isElaboratedTypeSpecifier()) {
9860    // If we evaluated the type to a record type, suggest putting
9861    // a tag in front.
9862    if (const RecordType *RT = T->getAs<RecordType>()) {
9863      RecordDecl *RD = RT->getDecl();
9864
9865      std::string InsertionText = std::string(" ") + RD->getKindName();
9866
9867      Diag(TypeRange.getBegin(),
9868           getLangOpts().CPlusPlus0x ?
9869             diag::warn_cxx98_compat_unelaborated_friend_type :
9870             diag::ext_unelaborated_friend_type)
9871        << (unsigned) RD->getTagKind()
9872        << T
9873        << FixItHint::CreateInsertion(PP.getLocForEndOfToken(FriendLoc),
9874                                      InsertionText);
9875    } else {
9876      Diag(FriendLoc,
9877           getLangOpts().CPlusPlus0x ?
9878             diag::warn_cxx98_compat_nonclass_type_friend :
9879             diag::ext_nonclass_type_friend)
9880        << T
9881        << SourceRange(FriendLoc, TypeRange.getEnd());
9882    }
9883  } else if (T->getAs<EnumType>()) {
9884    Diag(FriendLoc,
9885         getLangOpts().CPlusPlus0x ?
9886           diag::warn_cxx98_compat_enum_friend :
9887           diag::ext_enum_friend)
9888      << T
9889      << SourceRange(FriendLoc, TypeRange.getEnd());
9890  }
9891
9892  // C++0x [class.friend]p3:
9893  //   If the type specifier in a friend declaration designates a (possibly
9894  //   cv-qualified) class type, that class is declared as a friend; otherwise,
9895  //   the friend declaration is ignored.
9896
9897  // FIXME: C++0x has some syntactic restrictions on friend type declarations
9898  // in [class.friend]p3 that we do not implement.
9899
9900  return FriendDecl::Create(Context, CurContext, Loc, TSInfo, FriendLoc);
9901}
9902
9903/// Handle a friend tag declaration where the scope specifier was
9904/// templated.
9905Decl *Sema::ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc,
9906                                    unsigned TagSpec, SourceLocation TagLoc,
9907                                    CXXScopeSpec &SS,
9908                                    IdentifierInfo *Name, SourceLocation NameLoc,
9909                                    AttributeList *Attr,
9910                                    MultiTemplateParamsArg TempParamLists) {
9911  TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
9912
9913  bool isExplicitSpecialization = false;
9914  bool Invalid = false;
9915
9916  if (TemplateParameterList *TemplateParams
9917        = MatchTemplateParametersToScopeSpecifier(TagLoc, NameLoc, SS,
9918                                                  TempParamLists.get(),
9919                                                  TempParamLists.size(),
9920                                                  /*friend*/ true,
9921                                                  isExplicitSpecialization,
9922                                                  Invalid)) {
9923    if (TemplateParams->size() > 0) {
9924      // This is a declaration of a class template.
9925      if (Invalid)
9926        return 0;
9927
9928      return CheckClassTemplate(S, TagSpec, TUK_Friend, TagLoc,
9929                                SS, Name, NameLoc, Attr,
9930                                TemplateParams, AS_public,
9931                                /*ModulePrivateLoc=*/SourceLocation(),
9932                                TempParamLists.size() - 1,
9933                   (TemplateParameterList**) TempParamLists.release()).take();
9934    } else {
9935      // The "template<>" header is extraneous.
9936      Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams)
9937        << TypeWithKeyword::getTagTypeKindName(Kind) << Name;
9938      isExplicitSpecialization = true;
9939    }
9940  }
9941
9942  if (Invalid) return 0;
9943
9944  bool isAllExplicitSpecializations = true;
9945  for (unsigned I = TempParamLists.size(); I-- > 0; ) {
9946    if (TempParamLists.get()[I]->size()) {
9947      isAllExplicitSpecializations = false;
9948      break;
9949    }
9950  }
9951
9952  // FIXME: don't ignore attributes.
9953
9954  // If it's explicit specializations all the way down, just forget
9955  // about the template header and build an appropriate non-templated
9956  // friend.  TODO: for source fidelity, remember the headers.
9957  if (isAllExplicitSpecializations) {
9958    if (SS.isEmpty()) {
9959      bool Owned = false;
9960      bool IsDependent = false;
9961      return ActOnTag(S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc,
9962                      Attr, AS_public,
9963                      /*ModulePrivateLoc=*/SourceLocation(),
9964                      MultiTemplateParamsArg(), Owned, IsDependent,
9965                      /*ScopedEnumKWLoc=*/SourceLocation(),
9966                      /*ScopedEnumUsesClassTag=*/false,
9967                      /*UnderlyingType=*/TypeResult());
9968    }
9969
9970    NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
9971    ElaboratedTypeKeyword Keyword
9972      = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
9973    QualType T = CheckTypenameType(Keyword, TagLoc, QualifierLoc,
9974                                   *Name, NameLoc);
9975    if (T.isNull())
9976      return 0;
9977
9978    TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
9979    if (isa<DependentNameType>(T)) {
9980      DependentNameTypeLoc TL = cast<DependentNameTypeLoc>(TSI->getTypeLoc());
9981      TL.setElaboratedKeywordLoc(TagLoc);
9982      TL.setQualifierLoc(QualifierLoc);
9983      TL.setNameLoc(NameLoc);
9984    } else {
9985      ElaboratedTypeLoc TL = cast<ElaboratedTypeLoc>(TSI->getTypeLoc());
9986      TL.setElaboratedKeywordLoc(TagLoc);
9987      TL.setQualifierLoc(QualifierLoc);
9988      cast<TypeSpecTypeLoc>(TL.getNamedTypeLoc()).setNameLoc(NameLoc);
9989    }
9990
9991    FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
9992                                            TSI, FriendLoc);
9993    Friend->setAccess(AS_public);
9994    CurContext->addDecl(Friend);
9995    return Friend;
9996  }
9997
9998  assert(SS.isNotEmpty() && "valid templated tag with no SS and no direct?");
9999
10000
10001
10002  // Handle the case of a templated-scope friend class.  e.g.
10003  //   template <class T> class A<T>::B;
10004  // FIXME: we don't support these right now.
10005  ElaboratedTypeKeyword ETK = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
10006  QualType T = Context.getDependentNameType(ETK, SS.getScopeRep(), Name);
10007  TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
10008  DependentNameTypeLoc TL = cast<DependentNameTypeLoc>(TSI->getTypeLoc());
10009  TL.setElaboratedKeywordLoc(TagLoc);
10010  TL.setQualifierLoc(SS.getWithLocInContext(Context));
10011  TL.setNameLoc(NameLoc);
10012
10013  FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
10014                                          TSI, FriendLoc);
10015  Friend->setAccess(AS_public);
10016  Friend->setUnsupportedFriend(true);
10017  CurContext->addDecl(Friend);
10018  return Friend;
10019}
10020
10021
10022/// Handle a friend type declaration.  This works in tandem with
10023/// ActOnTag.
10024///
10025/// Notes on friend class templates:
10026///
10027/// We generally treat friend class declarations as if they were
10028/// declaring a class.  So, for example, the elaborated type specifier
10029/// in a friend declaration is required to obey the restrictions of a
10030/// class-head (i.e. no typedefs in the scope chain), template
10031/// parameters are required to match up with simple template-ids, &c.
10032/// However, unlike when declaring a template specialization, it's
10033/// okay to refer to a template specialization without an empty
10034/// template parameter declaration, e.g.
10035///   friend class A<T>::B<unsigned>;
10036/// We permit this as a special case; if there are any template
10037/// parameters present at all, require proper matching, i.e.
10038///   template <> template \<class T> friend class A<int>::B;
10039Decl *Sema::ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS,
10040                                MultiTemplateParamsArg TempParams) {
10041  SourceLocation Loc = DS.getLocStart();
10042
10043  assert(DS.isFriendSpecified());
10044  assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
10045
10046  // Try to convert the decl specifier to a type.  This works for
10047  // friend templates because ActOnTag never produces a ClassTemplateDecl
10048  // for a TUK_Friend.
10049  Declarator TheDeclarator(DS, Declarator::MemberContext);
10050  TypeSourceInfo *TSI = GetTypeForDeclarator(TheDeclarator, S);
10051  QualType T = TSI->getType();
10052  if (TheDeclarator.isInvalidType())
10053    return 0;
10054
10055  if (DiagnoseUnexpandedParameterPack(Loc, TSI, UPPC_FriendDeclaration))
10056    return 0;
10057
10058  // This is definitely an error in C++98.  It's probably meant to
10059  // be forbidden in C++0x, too, but the specification is just
10060  // poorly written.
10061  //
10062  // The problem is with declarations like the following:
10063  //   template <T> friend A<T>::foo;
10064  // where deciding whether a class C is a friend or not now hinges
10065  // on whether there exists an instantiation of A that causes
10066  // 'foo' to equal C.  There are restrictions on class-heads
10067  // (which we declare (by fiat) elaborated friend declarations to
10068  // be) that makes this tractable.
10069  //
10070  // FIXME: handle "template <> friend class A<T>;", which
10071  // is possibly well-formed?  Who even knows?
10072  if (TempParams.size() && !T->isElaboratedTypeSpecifier()) {
10073    Diag(Loc, diag::err_tagless_friend_type_template)
10074      << DS.getSourceRange();
10075    return 0;
10076  }
10077
10078  // C++98 [class.friend]p1: A friend of a class is a function
10079  //   or class that is not a member of the class . . .
10080  // This is fixed in DR77, which just barely didn't make the C++03
10081  // deadline.  It's also a very silly restriction that seriously
10082  // affects inner classes and which nobody else seems to implement;
10083  // thus we never diagnose it, not even in -pedantic.
10084  //
10085  // But note that we could warn about it: it's always useless to
10086  // friend one of your own members (it's not, however, worthless to
10087  // friend a member of an arbitrary specialization of your template).
10088
10089  Decl *D;
10090  if (unsigned NumTempParamLists = TempParams.size())
10091    D = FriendTemplateDecl::Create(Context, CurContext, Loc,
10092                                   NumTempParamLists,
10093                                   TempParams.release(),
10094                                   TSI,
10095                                   DS.getFriendSpecLoc());
10096  else
10097    D = CheckFriendTypeDecl(Loc, DS.getFriendSpecLoc(), TSI);
10098
10099  if (!D)
10100    return 0;
10101
10102  D->setAccess(AS_public);
10103  CurContext->addDecl(D);
10104
10105  return D;
10106}
10107
10108Decl *Sema::ActOnFriendFunctionDecl(Scope *S, Declarator &D,
10109                                    MultiTemplateParamsArg TemplateParams) {
10110  const DeclSpec &DS = D.getDeclSpec();
10111
10112  assert(DS.isFriendSpecified());
10113  assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
10114
10115  SourceLocation Loc = D.getIdentifierLoc();
10116  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
10117
10118  // C++ [class.friend]p1
10119  //   A friend of a class is a function or class....
10120  // Note that this sees through typedefs, which is intended.
10121  // It *doesn't* see through dependent types, which is correct
10122  // according to [temp.arg.type]p3:
10123  //   If a declaration acquires a function type through a
10124  //   type dependent on a template-parameter and this causes
10125  //   a declaration that does not use the syntactic form of a
10126  //   function declarator to have a function type, the program
10127  //   is ill-formed.
10128  if (!TInfo->getType()->isFunctionType()) {
10129    Diag(Loc, diag::err_unexpected_friend);
10130
10131    // It might be worthwhile to try to recover by creating an
10132    // appropriate declaration.
10133    return 0;
10134  }
10135
10136  // C++ [namespace.memdef]p3
10137  //  - If a friend declaration in a non-local class first declares a
10138  //    class or function, the friend class or function is a member
10139  //    of the innermost enclosing namespace.
10140  //  - The name of the friend is not found by simple name lookup
10141  //    until a matching declaration is provided in that namespace
10142  //    scope (either before or after the class declaration granting
10143  //    friendship).
10144  //  - If a friend function is called, its name may be found by the
10145  //    name lookup that considers functions from namespaces and
10146  //    classes associated with the types of the function arguments.
10147  //  - When looking for a prior declaration of a class or a function
10148  //    declared as a friend, scopes outside the innermost enclosing
10149  //    namespace scope are not considered.
10150
10151  CXXScopeSpec &SS = D.getCXXScopeSpec();
10152  DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
10153  DeclarationName Name = NameInfo.getName();
10154  assert(Name);
10155
10156  // Check for unexpanded parameter packs.
10157  if (DiagnoseUnexpandedParameterPack(Loc, TInfo, UPPC_FriendDeclaration) ||
10158      DiagnoseUnexpandedParameterPack(NameInfo, UPPC_FriendDeclaration) ||
10159      DiagnoseUnexpandedParameterPack(SS, UPPC_FriendDeclaration))
10160    return 0;
10161
10162  // The context we found the declaration in, or in which we should
10163  // create the declaration.
10164  DeclContext *DC;
10165  Scope *DCScope = S;
10166  LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
10167                        ForRedeclaration);
10168
10169  // FIXME: there are different rules in local classes
10170
10171  // There are four cases here.
10172  //   - There's no scope specifier, in which case we just go to the
10173  //     appropriate scope and look for a function or function template
10174  //     there as appropriate.
10175  // Recover from invalid scope qualifiers as if they just weren't there.
10176  if (SS.isInvalid() || !SS.isSet()) {
10177    // C++0x [namespace.memdef]p3:
10178    //   If the name in a friend declaration is neither qualified nor
10179    //   a template-id and the declaration is a function or an
10180    //   elaborated-type-specifier, the lookup to determine whether
10181    //   the entity has been previously declared shall not consider
10182    //   any scopes outside the innermost enclosing namespace.
10183    // C++0x [class.friend]p11:
10184    //   If a friend declaration appears in a local class and the name
10185    //   specified is an unqualified name, a prior declaration is
10186    //   looked up without considering scopes that are outside the
10187    //   innermost enclosing non-class scope. For a friend function
10188    //   declaration, if there is no prior declaration, the program is
10189    //   ill-formed.
10190    bool isLocal = cast<CXXRecordDecl>(CurContext)->isLocalClass();
10191    bool isTemplateId = D.getName().getKind() == UnqualifiedId::IK_TemplateId;
10192
10193    // Find the appropriate context according to the above.
10194    DC = CurContext;
10195    while (true) {
10196      // Skip class contexts.  If someone can cite chapter and verse
10197      // for this behavior, that would be nice --- it's what GCC and
10198      // EDG do, and it seems like a reasonable intent, but the spec
10199      // really only says that checks for unqualified existing
10200      // declarations should stop at the nearest enclosing namespace,
10201      // not that they should only consider the nearest enclosing
10202      // namespace.
10203      while (DC->isRecord() || DC->isTransparentContext())
10204        DC = DC->getParent();
10205
10206      LookupQualifiedName(Previous, DC);
10207
10208      // TODO: decide what we think about using declarations.
10209      if (isLocal || !Previous.empty())
10210        break;
10211
10212      if (isTemplateId) {
10213        if (isa<TranslationUnitDecl>(DC)) break;
10214      } else {
10215        if (DC->isFileContext()) break;
10216      }
10217      DC = DC->getParent();
10218    }
10219
10220    // C++ [class.friend]p1: A friend of a class is a function or
10221    //   class that is not a member of the class . . .
10222    // C++11 changes this for both friend types and functions.
10223    // Most C++ 98 compilers do seem to give an error here, so
10224    // we do, too.
10225    if (!Previous.empty() && DC->Equals(CurContext))
10226      Diag(DS.getFriendSpecLoc(),
10227           getLangOpts().CPlusPlus0x ?
10228             diag::warn_cxx98_compat_friend_is_member :
10229             diag::err_friend_is_member);
10230
10231    DCScope = getScopeForDeclContext(S, DC);
10232
10233    // C++ [class.friend]p6:
10234    //   A function can be defined in a friend declaration of a class if and
10235    //   only if the class is a non-local class (9.8), the function name is
10236    //   unqualified, and the function has namespace scope.
10237    if (isLocal && D.isFunctionDefinition()) {
10238      Diag(NameInfo.getBeginLoc(), diag::err_friend_def_in_local_class);
10239    }
10240
10241  //   - There's a non-dependent scope specifier, in which case we
10242  //     compute it and do a previous lookup there for a function
10243  //     or function template.
10244  } else if (!SS.getScopeRep()->isDependent()) {
10245    DC = computeDeclContext(SS);
10246    if (!DC) return 0;
10247
10248    if (RequireCompleteDeclContext(SS, DC)) return 0;
10249
10250    LookupQualifiedName(Previous, DC);
10251
10252    // Ignore things found implicitly in the wrong scope.
10253    // TODO: better diagnostics for this case.  Suggesting the right
10254    // qualified scope would be nice...
10255    LookupResult::Filter F = Previous.makeFilter();
10256    while (F.hasNext()) {
10257      NamedDecl *D = F.next();
10258      if (!DC->InEnclosingNamespaceSetOf(
10259              D->getDeclContext()->getRedeclContext()))
10260        F.erase();
10261    }
10262    F.done();
10263
10264    if (Previous.empty()) {
10265      D.setInvalidType();
10266      Diag(Loc, diag::err_qualified_friend_not_found)
10267          << Name << TInfo->getType();
10268      return 0;
10269    }
10270
10271    // C++ [class.friend]p1: A friend of a class is a function or
10272    //   class that is not a member of the class . . .
10273    if (DC->Equals(CurContext))
10274      Diag(DS.getFriendSpecLoc(),
10275           getLangOpts().CPlusPlus0x ?
10276             diag::warn_cxx98_compat_friend_is_member :
10277             diag::err_friend_is_member);
10278
10279    if (D.isFunctionDefinition()) {
10280      // C++ [class.friend]p6:
10281      //   A function can be defined in a friend declaration of a class if and
10282      //   only if the class is a non-local class (9.8), the function name is
10283      //   unqualified, and the function has namespace scope.
10284      SemaDiagnosticBuilder DB
10285        = Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def);
10286
10287      DB << SS.getScopeRep();
10288      if (DC->isFileContext())
10289        DB << FixItHint::CreateRemoval(SS.getRange());
10290      SS.clear();
10291    }
10292
10293  //   - There's a scope specifier that does not match any template
10294  //     parameter lists, in which case we use some arbitrary context,
10295  //     create a method or method template, and wait for instantiation.
10296  //   - There's a scope specifier that does match some template
10297  //     parameter lists, which we don't handle right now.
10298  } else {
10299    if (D.isFunctionDefinition()) {
10300      // C++ [class.friend]p6:
10301      //   A function can be defined in a friend declaration of a class if and
10302      //   only if the class is a non-local class (9.8), the function name is
10303      //   unqualified, and the function has namespace scope.
10304      Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def)
10305        << SS.getScopeRep();
10306    }
10307
10308    DC = CurContext;
10309    assert(isa<CXXRecordDecl>(DC) && "friend declaration not in class?");
10310  }
10311
10312  if (!DC->isRecord()) {
10313    // This implies that it has to be an operator or function.
10314    if (D.getName().getKind() == UnqualifiedId::IK_ConstructorName ||
10315        D.getName().getKind() == UnqualifiedId::IK_DestructorName ||
10316        D.getName().getKind() == UnqualifiedId::IK_ConversionFunctionId) {
10317      Diag(Loc, diag::err_introducing_special_friend) <<
10318        (D.getName().getKind() == UnqualifiedId::IK_ConstructorName ? 0 :
10319         D.getName().getKind() == UnqualifiedId::IK_DestructorName ? 1 : 2);
10320      return 0;
10321    }
10322  }
10323
10324  // FIXME: This is an egregious hack to cope with cases where the scope stack
10325  // does not contain the declaration context, i.e., in an out-of-line
10326  // definition of a class.
10327  Scope FakeDCScope(S, Scope::DeclScope, Diags);
10328  if (!DCScope) {
10329    FakeDCScope.setEntity(DC);
10330    DCScope = &FakeDCScope;
10331  }
10332
10333  bool AddToScope = true;
10334  NamedDecl *ND = ActOnFunctionDeclarator(DCScope, D, DC, TInfo, Previous,
10335                                          move(TemplateParams), AddToScope);
10336  if (!ND) return 0;
10337
10338  assert(ND->getDeclContext() == DC);
10339  assert(ND->getLexicalDeclContext() == CurContext);
10340
10341  // Add the function declaration to the appropriate lookup tables,
10342  // adjusting the redeclarations list as necessary.  We don't
10343  // want to do this yet if the friending class is dependent.
10344  //
10345  // Also update the scope-based lookup if the target context's
10346  // lookup context is in lexical scope.
10347  if (!CurContext->isDependentContext()) {
10348    DC = DC->getRedeclContext();
10349    DC->makeDeclVisibleInContext(ND);
10350    if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
10351      PushOnScopeChains(ND, EnclosingScope, /*AddToContext=*/ false);
10352  }
10353
10354  FriendDecl *FrD = FriendDecl::Create(Context, CurContext,
10355                                       D.getIdentifierLoc(), ND,
10356                                       DS.getFriendSpecLoc());
10357  FrD->setAccess(AS_public);
10358  CurContext->addDecl(FrD);
10359
10360  if (ND->isInvalidDecl())
10361    FrD->setInvalidDecl();
10362  else {
10363    FunctionDecl *FD;
10364    if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
10365      FD = FTD->getTemplatedDecl();
10366    else
10367      FD = cast<FunctionDecl>(ND);
10368
10369    // Mark templated-scope function declarations as unsupported.
10370    if (FD->getNumTemplateParameterLists())
10371      FrD->setUnsupportedFriend(true);
10372  }
10373
10374  return ND;
10375}
10376
10377void Sema::SetDeclDeleted(Decl *Dcl, SourceLocation DelLoc) {
10378  AdjustDeclIfTemplate(Dcl);
10379
10380  FunctionDecl *Fn = dyn_cast<FunctionDecl>(Dcl);
10381  if (!Fn) {
10382    Diag(DelLoc, diag::err_deleted_non_function);
10383    return;
10384  }
10385  if (const FunctionDecl *Prev = Fn->getPreviousDecl()) {
10386    // Don't consider the implicit declaration we generate for explicit
10387    // specializations. FIXME: Do not generate these implicit declarations.
10388    if ((Prev->getTemplateSpecializationKind() != TSK_ExplicitSpecialization
10389        || Prev->getPreviousDecl()) && !Prev->isDefined()) {
10390      Diag(DelLoc, diag::err_deleted_decl_not_first);
10391      Diag(Prev->getLocation(), diag::note_previous_declaration);
10392    }
10393    // If the declaration wasn't the first, we delete the function anyway for
10394    // recovery.
10395  }
10396  Fn->setDeletedAsWritten();
10397
10398  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Dcl);
10399  if (!MD)
10400    return;
10401
10402  // A deleted special member function is trivial if the corresponding
10403  // implicitly-declared function would have been.
10404  switch (getSpecialMember(MD)) {
10405  case CXXInvalid:
10406    break;
10407  case CXXDefaultConstructor:
10408    MD->setTrivial(MD->getParent()->hasTrivialDefaultConstructor());
10409    break;
10410  case CXXCopyConstructor:
10411    MD->setTrivial(MD->getParent()->hasTrivialCopyConstructor());
10412    break;
10413  case CXXMoveConstructor:
10414    MD->setTrivial(MD->getParent()->hasTrivialMoveConstructor());
10415    break;
10416  case CXXCopyAssignment:
10417    MD->setTrivial(MD->getParent()->hasTrivialCopyAssignment());
10418    break;
10419  case CXXMoveAssignment:
10420    MD->setTrivial(MD->getParent()->hasTrivialMoveAssignment());
10421    break;
10422  case CXXDestructor:
10423    MD->setTrivial(MD->getParent()->hasTrivialDestructor());
10424    break;
10425  }
10426}
10427
10428void Sema::SetDeclDefaulted(Decl *Dcl, SourceLocation DefaultLoc) {
10429  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Dcl);
10430
10431  if (MD) {
10432    if (MD->getParent()->isDependentType()) {
10433      MD->setDefaulted();
10434      MD->setExplicitlyDefaulted();
10435      return;
10436    }
10437
10438    CXXSpecialMember Member = getSpecialMember(MD);
10439    if (Member == CXXInvalid) {
10440      Diag(DefaultLoc, diag::err_default_special_members);
10441      return;
10442    }
10443
10444    MD->setDefaulted();
10445    MD->setExplicitlyDefaulted();
10446
10447    // If this definition appears within the record, do the checking when
10448    // the record is complete.
10449    const FunctionDecl *Primary = MD;
10450    if (MD->getTemplatedKind() != FunctionDecl::TK_NonTemplate)
10451      // Find the uninstantiated declaration that actually had the '= default'
10452      // on it.
10453      MD->getTemplateInstantiationPattern()->isDefined(Primary);
10454
10455    if (Primary == Primary->getCanonicalDecl())
10456      return;
10457
10458    CheckExplicitlyDefaultedSpecialMember(MD);
10459
10460    switch (Member) {
10461    case CXXDefaultConstructor: {
10462      CXXConstructorDecl *CD = cast<CXXConstructorDecl>(MD);
10463      if (!CD->isInvalidDecl())
10464        DefineImplicitDefaultConstructor(DefaultLoc, CD);
10465      break;
10466    }
10467
10468    case CXXCopyConstructor: {
10469      CXXConstructorDecl *CD = cast<CXXConstructorDecl>(MD);
10470      if (!CD->isInvalidDecl())
10471        DefineImplicitCopyConstructor(DefaultLoc, CD);
10472      break;
10473    }
10474
10475    case CXXCopyAssignment: {
10476      if (!MD->isInvalidDecl())
10477        DefineImplicitCopyAssignment(DefaultLoc, MD);
10478      break;
10479    }
10480
10481    case CXXDestructor: {
10482      CXXDestructorDecl *DD = cast<CXXDestructorDecl>(MD);
10483      if (!DD->isInvalidDecl())
10484        DefineImplicitDestructor(DefaultLoc, DD);
10485      break;
10486    }
10487
10488    case CXXMoveConstructor: {
10489      CXXConstructorDecl *CD = cast<CXXConstructorDecl>(MD);
10490      if (!CD->isInvalidDecl())
10491        DefineImplicitMoveConstructor(DefaultLoc, CD);
10492      break;
10493    }
10494
10495    case CXXMoveAssignment: {
10496      if (!MD->isInvalidDecl())
10497        DefineImplicitMoveAssignment(DefaultLoc, MD);
10498      break;
10499    }
10500
10501    case CXXInvalid:
10502      llvm_unreachable("Invalid special member.");
10503    }
10504  } else {
10505    Diag(DefaultLoc, diag::err_default_special_members);
10506  }
10507}
10508
10509static void SearchForReturnInStmt(Sema &Self, Stmt *S) {
10510  for (Stmt::child_range CI = S->children(); CI; ++CI) {
10511    Stmt *SubStmt = *CI;
10512    if (!SubStmt)
10513      continue;
10514    if (isa<ReturnStmt>(SubStmt))
10515      Self.Diag(SubStmt->getLocStart(),
10516           diag::err_return_in_constructor_handler);
10517    if (!isa<Expr>(SubStmt))
10518      SearchForReturnInStmt(Self, SubStmt);
10519  }
10520}
10521
10522void Sema::DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock) {
10523  for (unsigned I = 0, E = TryBlock->getNumHandlers(); I != E; ++I) {
10524    CXXCatchStmt *Handler = TryBlock->getHandler(I);
10525    SearchForReturnInStmt(*this, Handler);
10526  }
10527}
10528
10529bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
10530                                             const CXXMethodDecl *Old) {
10531  QualType NewTy = New->getType()->getAs<FunctionType>()->getResultType();
10532  QualType OldTy = Old->getType()->getAs<FunctionType>()->getResultType();
10533
10534  if (Context.hasSameType(NewTy, OldTy) ||
10535      NewTy->isDependentType() || OldTy->isDependentType())
10536    return false;
10537
10538  // Check if the return types are covariant
10539  QualType NewClassTy, OldClassTy;
10540
10541  /// Both types must be pointers or references to classes.
10542  if (const PointerType *NewPT = NewTy->getAs<PointerType>()) {
10543    if (const PointerType *OldPT = OldTy->getAs<PointerType>()) {
10544      NewClassTy = NewPT->getPointeeType();
10545      OldClassTy = OldPT->getPointeeType();
10546    }
10547  } else if (const ReferenceType *NewRT = NewTy->getAs<ReferenceType>()) {
10548    if (const ReferenceType *OldRT = OldTy->getAs<ReferenceType>()) {
10549      if (NewRT->getTypeClass() == OldRT->getTypeClass()) {
10550        NewClassTy = NewRT->getPointeeType();
10551        OldClassTy = OldRT->getPointeeType();
10552      }
10553    }
10554  }
10555
10556  // The return types aren't either both pointers or references to a class type.
10557  if (NewClassTy.isNull()) {
10558    Diag(New->getLocation(),
10559         diag::err_different_return_type_for_overriding_virtual_function)
10560      << New->getDeclName() << NewTy << OldTy;
10561    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10562
10563    return true;
10564  }
10565
10566  // C++ [class.virtual]p6:
10567  //   If the return type of D::f differs from the return type of B::f, the
10568  //   class type in the return type of D::f shall be complete at the point of
10569  //   declaration of D::f or shall be the class type D.
10570  if (const RecordType *RT = NewClassTy->getAs<RecordType>()) {
10571    if (!RT->isBeingDefined() &&
10572        RequireCompleteType(New->getLocation(), NewClassTy,
10573                            diag::err_covariant_return_incomplete,
10574                            New->getDeclName()))
10575    return true;
10576  }
10577
10578  if (!Context.hasSameUnqualifiedType(NewClassTy, OldClassTy)) {
10579    // Check if the new class derives from the old class.
10580    if (!IsDerivedFrom(NewClassTy, OldClassTy)) {
10581      Diag(New->getLocation(),
10582           diag::err_covariant_return_not_derived)
10583      << New->getDeclName() << NewTy << OldTy;
10584      Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10585      return true;
10586    }
10587
10588    // Check if we the conversion from derived to base is valid.
10589    if (CheckDerivedToBaseConversion(NewClassTy, OldClassTy,
10590                    diag::err_covariant_return_inaccessible_base,
10591                    diag::err_covariant_return_ambiguous_derived_to_base_conv,
10592                    // FIXME: Should this point to the return type?
10593                    New->getLocation(), SourceRange(), New->getDeclName(), 0)) {
10594      // FIXME: this note won't trigger for delayed access control
10595      // diagnostics, and it's impossible to get an undelayed error
10596      // here from access control during the original parse because
10597      // the ParsingDeclSpec/ParsingDeclarator are still in scope.
10598      Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10599      return true;
10600    }
10601  }
10602
10603  // The qualifiers of the return types must be the same.
10604  if (NewTy.getLocalCVRQualifiers() != OldTy.getLocalCVRQualifiers()) {
10605    Diag(New->getLocation(),
10606         diag::err_covariant_return_type_different_qualifications)
10607    << New->getDeclName() << NewTy << OldTy;
10608    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10609    return true;
10610  };
10611
10612
10613  // The new class type must have the same or less qualifiers as the old type.
10614  if (NewClassTy.isMoreQualifiedThan(OldClassTy)) {
10615    Diag(New->getLocation(),
10616         diag::err_covariant_return_type_class_type_more_qualified)
10617    << New->getDeclName() << NewTy << OldTy;
10618    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10619    return true;
10620  };
10621
10622  return false;
10623}
10624
10625/// \brief Mark the given method pure.
10626///
10627/// \param Method the method to be marked pure.
10628///
10629/// \param InitRange the source range that covers the "0" initializer.
10630bool Sema::CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange) {
10631  SourceLocation EndLoc = InitRange.getEnd();
10632  if (EndLoc.isValid())
10633    Method->setRangeEnd(EndLoc);
10634
10635  if (Method->isVirtual() || Method->getParent()->isDependentContext()) {
10636    Method->setPure();
10637    return false;
10638  }
10639
10640  if (!Method->isInvalidDecl())
10641    Diag(Method->getLocation(), diag::err_non_virtual_pure)
10642      << Method->getDeclName() << InitRange;
10643  return true;
10644}
10645
10646/// \brief Determine whether the given declaration is a static data member.
10647static bool isStaticDataMember(Decl *D) {
10648  VarDecl *Var = dyn_cast_or_null<VarDecl>(D);
10649  if (!Var)
10650    return false;
10651
10652  return Var->isStaticDataMember();
10653}
10654/// ActOnCXXEnterDeclInitializer - Invoked when we are about to parse
10655/// an initializer for the out-of-line declaration 'Dcl'.  The scope
10656/// is a fresh scope pushed for just this purpose.
10657///
10658/// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
10659/// static data member of class X, names should be looked up in the scope of
10660/// class X.
10661void Sema::ActOnCXXEnterDeclInitializer(Scope *S, Decl *D) {
10662  // If there is no declaration, there was an error parsing it.
10663  if (D == 0 || D->isInvalidDecl()) return;
10664
10665  // We should only get called for declarations with scope specifiers, like:
10666  //   int foo::bar;
10667  assert(D->isOutOfLine());
10668  EnterDeclaratorContext(S, D->getDeclContext());
10669
10670  // If we are parsing the initializer for a static data member, push a
10671  // new expression evaluation context that is associated with this static
10672  // data member.
10673  if (isStaticDataMember(D))
10674    PushExpressionEvaluationContext(PotentiallyEvaluated, D);
10675}
10676
10677/// ActOnCXXExitDeclInitializer - Invoked after we are finished parsing an
10678/// initializer for the out-of-line declaration 'D'.
10679void Sema::ActOnCXXExitDeclInitializer(Scope *S, Decl *D) {
10680  // If there is no declaration, there was an error parsing it.
10681  if (D == 0 || D->isInvalidDecl()) return;
10682
10683  if (isStaticDataMember(D))
10684    PopExpressionEvaluationContext();
10685
10686  assert(D->isOutOfLine());
10687  ExitDeclaratorContext(S);
10688}
10689
10690/// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a
10691/// C++ if/switch/while/for statement.
10692/// e.g: "if (int x = f()) {...}"
10693DeclResult Sema::ActOnCXXConditionDeclaration(Scope *S, Declarator &D) {
10694  // C++ 6.4p2:
10695  // The declarator shall not specify a function or an array.
10696  // The type-specifier-seq shall not contain typedef and shall not declare a
10697  // new class or enumeration.
10698  assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
10699         "Parser allowed 'typedef' as storage class of condition decl.");
10700
10701  Decl *Dcl = ActOnDeclarator(S, D);
10702  if (!Dcl)
10703    return true;
10704
10705  if (isa<FunctionDecl>(Dcl)) { // The declarator shall not specify a function.
10706    Diag(Dcl->getLocation(), diag::err_invalid_use_of_function_type)
10707      << D.getSourceRange();
10708    return true;
10709  }
10710
10711  return Dcl;
10712}
10713
10714void Sema::LoadExternalVTableUses() {
10715  if (!ExternalSource)
10716    return;
10717
10718  SmallVector<ExternalVTableUse, 4> VTables;
10719  ExternalSource->ReadUsedVTables(VTables);
10720  SmallVector<VTableUse, 4> NewUses;
10721  for (unsigned I = 0, N = VTables.size(); I != N; ++I) {
10722    llvm::DenseMap<CXXRecordDecl *, bool>::iterator Pos
10723      = VTablesUsed.find(VTables[I].Record);
10724    // Even if a definition wasn't required before, it may be required now.
10725    if (Pos != VTablesUsed.end()) {
10726      if (!Pos->second && VTables[I].DefinitionRequired)
10727        Pos->second = true;
10728      continue;
10729    }
10730
10731    VTablesUsed[VTables[I].Record] = VTables[I].DefinitionRequired;
10732    NewUses.push_back(VTableUse(VTables[I].Record, VTables[I].Location));
10733  }
10734
10735  VTableUses.insert(VTableUses.begin(), NewUses.begin(), NewUses.end());
10736}
10737
10738void Sema::MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class,
10739                          bool DefinitionRequired) {
10740  // Ignore any vtable uses in unevaluated operands or for classes that do
10741  // not have a vtable.
10742  if (!Class->isDynamicClass() || Class->isDependentContext() ||
10743      CurContext->isDependentContext() ||
10744      ExprEvalContexts.back().Context == Unevaluated)
10745    return;
10746
10747  // Try to insert this class into the map.
10748  LoadExternalVTableUses();
10749  Class = cast<CXXRecordDecl>(Class->getCanonicalDecl());
10750  std::pair<llvm::DenseMap<CXXRecordDecl *, bool>::iterator, bool>
10751    Pos = VTablesUsed.insert(std::make_pair(Class, DefinitionRequired));
10752  if (!Pos.second) {
10753    // If we already had an entry, check to see if we are promoting this vtable
10754    // to required a definition. If so, we need to reappend to the VTableUses
10755    // list, since we may have already processed the first entry.
10756    if (DefinitionRequired && !Pos.first->second) {
10757      Pos.first->second = true;
10758    } else {
10759      // Otherwise, we can early exit.
10760      return;
10761    }
10762  }
10763
10764  // Local classes need to have their virtual members marked
10765  // immediately. For all other classes, we mark their virtual members
10766  // at the end of the translation unit.
10767  if (Class->isLocalClass())
10768    MarkVirtualMembersReferenced(Loc, Class);
10769  else
10770    VTableUses.push_back(std::make_pair(Class, Loc));
10771}
10772
10773bool Sema::DefineUsedVTables() {
10774  LoadExternalVTableUses();
10775  if (VTableUses.empty())
10776    return false;
10777
10778  // Note: The VTableUses vector could grow as a result of marking
10779  // the members of a class as "used", so we check the size each
10780  // time through the loop and prefer indices (which are stable) to
10781  // iterators (which are not).
10782  bool DefinedAnything = false;
10783  for (unsigned I = 0; I != VTableUses.size(); ++I) {
10784    CXXRecordDecl *Class = VTableUses[I].first->getDefinition();
10785    if (!Class)
10786      continue;
10787
10788    SourceLocation Loc = VTableUses[I].second;
10789
10790    bool DefineVTable = true;
10791
10792    // If this class has a key function, but that key function is
10793    // defined in another translation unit, we don't need to emit the
10794    // vtable even though we're using it.
10795    const CXXMethodDecl *KeyFunction = Context.getKeyFunction(Class);
10796    if (KeyFunction && !KeyFunction->hasBody()) {
10797      switch (KeyFunction->getTemplateSpecializationKind()) {
10798      case TSK_Undeclared:
10799      case TSK_ExplicitSpecialization:
10800      case TSK_ExplicitInstantiationDeclaration:
10801        // The key function is in another translation unit.
10802        DefineVTable = false;
10803        break;
10804
10805      case TSK_ExplicitInstantiationDefinition:
10806      case TSK_ImplicitInstantiation:
10807        // We will be instantiating the key function.
10808        break;
10809      }
10810    } else if (!KeyFunction) {
10811      // If we have a class with no key function that is the subject
10812      // of an explicit instantiation declaration, suppress the
10813      // vtable; it will live with the explicit instantiation
10814      // definition.
10815      bool IsExplicitInstantiationDeclaration
10816        = Class->getTemplateSpecializationKind()
10817                                      == TSK_ExplicitInstantiationDeclaration;
10818      for (TagDecl::redecl_iterator R = Class->redecls_begin(),
10819                                 REnd = Class->redecls_end();
10820           R != REnd; ++R) {
10821        TemplateSpecializationKind TSK
10822          = cast<CXXRecordDecl>(*R)->getTemplateSpecializationKind();
10823        if (TSK == TSK_ExplicitInstantiationDeclaration)
10824          IsExplicitInstantiationDeclaration = true;
10825        else if (TSK == TSK_ExplicitInstantiationDefinition) {
10826          IsExplicitInstantiationDeclaration = false;
10827          break;
10828        }
10829      }
10830
10831      if (IsExplicitInstantiationDeclaration)
10832        DefineVTable = false;
10833    }
10834
10835    // The exception specifications for all virtual members may be needed even
10836    // if we are not providing an authoritative form of the vtable in this TU.
10837    // We may choose to emit it available_externally anyway.
10838    if (!DefineVTable) {
10839      MarkVirtualMemberExceptionSpecsNeeded(Loc, Class);
10840      continue;
10841    }
10842
10843    // Mark all of the virtual members of this class as referenced, so
10844    // that we can build a vtable. Then, tell the AST consumer that a
10845    // vtable for this class is required.
10846    DefinedAnything = true;
10847    MarkVirtualMembersReferenced(Loc, Class);
10848    CXXRecordDecl *Canonical = cast<CXXRecordDecl>(Class->getCanonicalDecl());
10849    Consumer.HandleVTable(Class, VTablesUsed[Canonical]);
10850
10851    // Optionally warn if we're emitting a weak vtable.
10852    if (Class->getLinkage() == ExternalLinkage &&
10853        Class->getTemplateSpecializationKind() != TSK_ImplicitInstantiation) {
10854      const FunctionDecl *KeyFunctionDef = 0;
10855      if (!KeyFunction ||
10856          (KeyFunction->hasBody(KeyFunctionDef) &&
10857           KeyFunctionDef->isInlined()))
10858        Diag(Class->getLocation(), Class->getTemplateSpecializationKind() ==
10859             TSK_ExplicitInstantiationDefinition
10860             ? diag::warn_weak_template_vtable : diag::warn_weak_vtable)
10861          << Class;
10862    }
10863  }
10864  VTableUses.clear();
10865
10866  return DefinedAnything;
10867}
10868
10869void Sema::MarkVirtualMemberExceptionSpecsNeeded(SourceLocation Loc,
10870                                                 const CXXRecordDecl *RD) {
10871  for (CXXRecordDecl::method_iterator I = RD->method_begin(),
10872                                      E = RD->method_end(); I != E; ++I)
10873    if ((*I)->isVirtual() && !(*I)->isPure())
10874      ResolveExceptionSpec(Loc, (*I)->getType()->castAs<FunctionProtoType>());
10875}
10876
10877void Sema::MarkVirtualMembersReferenced(SourceLocation Loc,
10878                                        const CXXRecordDecl *RD) {
10879  // Mark all functions which will appear in RD's vtable as used.
10880  CXXFinalOverriderMap FinalOverriders;
10881  RD->getFinalOverriders(FinalOverriders);
10882  for (CXXFinalOverriderMap::const_iterator I = FinalOverriders.begin(),
10883                                            E = FinalOverriders.end();
10884       I != E; ++I) {
10885    for (OverridingMethods::const_iterator OI = I->second.begin(),
10886                                           OE = I->second.end();
10887         OI != OE; ++OI) {
10888      assert(OI->second.size() > 0 && "no final overrider");
10889      CXXMethodDecl *Overrider = OI->second.front().Method;
10890
10891      // C++ [basic.def.odr]p2:
10892      //   [...] A virtual member function is used if it is not pure. [...]
10893      if (!Overrider->isPure())
10894        MarkFunctionReferenced(Loc, Overrider);
10895    }
10896  }
10897
10898  // Only classes that have virtual bases need a VTT.
10899  if (RD->getNumVBases() == 0)
10900    return;
10901
10902  for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
10903           e = RD->bases_end(); i != e; ++i) {
10904    const CXXRecordDecl *Base =
10905        cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
10906    if (Base->getNumVBases() == 0)
10907      continue;
10908    MarkVirtualMembersReferenced(Loc, Base);
10909  }
10910}
10911
10912/// SetIvarInitializers - This routine builds initialization ASTs for the
10913/// Objective-C implementation whose ivars need be initialized.
10914void Sema::SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation) {
10915  if (!getLangOpts().CPlusPlus)
10916    return;
10917  if (ObjCInterfaceDecl *OID = ObjCImplementation->getClassInterface()) {
10918    SmallVector<ObjCIvarDecl*, 8> ivars;
10919    CollectIvarsToConstructOrDestruct(OID, ivars);
10920    if (ivars.empty())
10921      return;
10922    SmallVector<CXXCtorInitializer*, 32> AllToInit;
10923    for (unsigned i = 0; i < ivars.size(); i++) {
10924      FieldDecl *Field = ivars[i];
10925      if (Field->isInvalidDecl())
10926        continue;
10927
10928      CXXCtorInitializer *Member;
10929      InitializedEntity InitEntity = InitializedEntity::InitializeMember(Field);
10930      InitializationKind InitKind =
10931        InitializationKind::CreateDefault(ObjCImplementation->getLocation());
10932
10933      InitializationSequence InitSeq(*this, InitEntity, InitKind, 0, 0);
10934      ExprResult MemberInit =
10935        InitSeq.Perform(*this, InitEntity, InitKind, MultiExprArg());
10936      MemberInit = MaybeCreateExprWithCleanups(MemberInit);
10937      // Note, MemberInit could actually come back empty if no initialization
10938      // is required (e.g., because it would call a trivial default constructor)
10939      if (!MemberInit.get() || MemberInit.isInvalid())
10940        continue;
10941
10942      Member =
10943        new (Context) CXXCtorInitializer(Context, Field, SourceLocation(),
10944                                         SourceLocation(),
10945                                         MemberInit.takeAs<Expr>(),
10946                                         SourceLocation());
10947      AllToInit.push_back(Member);
10948
10949      // Be sure that the destructor is accessible and is marked as referenced.
10950      if (const RecordType *RecordTy
10951                  = Context.getBaseElementType(Field->getType())
10952                                                        ->getAs<RecordType>()) {
10953                    CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl());
10954        if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
10955          MarkFunctionReferenced(Field->getLocation(), Destructor);
10956          CheckDestructorAccess(Field->getLocation(), Destructor,
10957                            PDiag(diag::err_access_dtor_ivar)
10958                              << Context.getBaseElementType(Field->getType()));
10959        }
10960      }
10961    }
10962    ObjCImplementation->setIvarInitializers(Context,
10963                                            AllToInit.data(), AllToInit.size());
10964  }
10965}
10966
10967static
10968void DelegatingCycleHelper(CXXConstructorDecl* Ctor,
10969                           llvm::SmallSet<CXXConstructorDecl*, 4> &Valid,
10970                           llvm::SmallSet<CXXConstructorDecl*, 4> &Invalid,
10971                           llvm::SmallSet<CXXConstructorDecl*, 4> &Current,
10972                           Sema &S) {
10973  llvm::SmallSet<CXXConstructorDecl*, 4>::iterator CI = Current.begin(),
10974                                                   CE = Current.end();
10975  if (Ctor->isInvalidDecl())
10976    return;
10977
10978  const FunctionDecl *FNTarget = 0;
10979  CXXConstructorDecl *Target;
10980
10981  // We ignore the result here since if we don't have a body, Target will be
10982  // null below.
10983  (void)Ctor->getTargetConstructor()->hasBody(FNTarget);
10984  Target
10985= const_cast<CXXConstructorDecl*>(cast_or_null<CXXConstructorDecl>(FNTarget));
10986
10987  CXXConstructorDecl *Canonical = Ctor->getCanonicalDecl(),
10988                     // Avoid dereferencing a null pointer here.
10989                     *TCanonical = Target ? Target->getCanonicalDecl() : 0;
10990
10991  if (!Current.insert(Canonical))
10992    return;
10993
10994  // We know that beyond here, we aren't chaining into a cycle.
10995  if (!Target || !Target->isDelegatingConstructor() ||
10996      Target->isInvalidDecl() || Valid.count(TCanonical)) {
10997    for (CI = Current.begin(), CE = Current.end(); CI != CE; ++CI)
10998      Valid.insert(*CI);
10999    Current.clear();
11000  // We've hit a cycle.
11001  } else if (TCanonical == Canonical || Invalid.count(TCanonical) ||
11002             Current.count(TCanonical)) {
11003    // If we haven't diagnosed this cycle yet, do so now.
11004    if (!Invalid.count(TCanonical)) {
11005      S.Diag((*Ctor->init_begin())->getSourceLocation(),
11006             diag::warn_delegating_ctor_cycle)
11007        << Ctor;
11008
11009      // Don't add a note for a function delegating directo to itself.
11010      if (TCanonical != Canonical)
11011        S.Diag(Target->getLocation(), diag::note_it_delegates_to);
11012
11013      CXXConstructorDecl *C = Target;
11014      while (C->getCanonicalDecl() != Canonical) {
11015        (void)C->getTargetConstructor()->hasBody(FNTarget);
11016        assert(FNTarget && "Ctor cycle through bodiless function");
11017
11018        C
11019       = const_cast<CXXConstructorDecl*>(cast<CXXConstructorDecl>(FNTarget));
11020        S.Diag(C->getLocation(), diag::note_which_delegates_to);
11021      }
11022    }
11023
11024    for (CI = Current.begin(), CE = Current.end(); CI != CE; ++CI)
11025      Invalid.insert(*CI);
11026    Current.clear();
11027  } else {
11028    DelegatingCycleHelper(Target, Valid, Invalid, Current, S);
11029  }
11030}
11031
11032
11033void Sema::CheckDelegatingCtorCycles() {
11034  llvm::SmallSet<CXXConstructorDecl*, 4> Valid, Invalid, Current;
11035
11036  llvm::SmallSet<CXXConstructorDecl*, 4>::iterator CI = Current.begin(),
11037                                                   CE = Current.end();
11038
11039  for (DelegatingCtorDeclsType::iterator
11040         I = DelegatingCtorDecls.begin(ExternalSource),
11041         E = DelegatingCtorDecls.end();
11042       I != E; ++I) {
11043   DelegatingCycleHelper(*I, Valid, Invalid, Current, *this);
11044  }
11045
11046  for (CI = Invalid.begin(), CE = Invalid.end(); CI != CE; ++CI)
11047    (*CI)->setInvalidDecl();
11048}
11049
11050namespace {
11051  /// \brief AST visitor that finds references to the 'this' expression.
11052  class FindCXXThisExpr : public RecursiveASTVisitor<FindCXXThisExpr> {
11053    Sema &S;
11054
11055  public:
11056    explicit FindCXXThisExpr(Sema &S) : S(S) { }
11057
11058    bool VisitCXXThisExpr(CXXThisExpr *E) {
11059      S.Diag(E->getLocation(), diag::err_this_static_member_func)
11060        << E->isImplicit();
11061      return false;
11062    }
11063  };
11064}
11065
11066bool Sema::checkThisInStaticMemberFunctionType(CXXMethodDecl *Method) {
11067  TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
11068  if (!TSInfo)
11069    return false;
11070
11071  TypeLoc TL = TSInfo->getTypeLoc();
11072  FunctionProtoTypeLoc *ProtoTL = dyn_cast<FunctionProtoTypeLoc>(&TL);
11073  if (!ProtoTL)
11074    return false;
11075
11076  // C++11 [expr.prim.general]p3:
11077  //   [The expression this] shall not appear before the optional
11078  //   cv-qualifier-seq and it shall not appear within the declaration of a
11079  //   static member function (although its type and value category are defined
11080  //   within a static member function as they are within a non-static member
11081  //   function). [ Note: this is because declaration matching does not occur
11082  //  until the complete declarator is known. - end note ]
11083  const FunctionProtoType *Proto = ProtoTL->getTypePtr();
11084  FindCXXThisExpr Finder(*this);
11085
11086  // If the return type came after the cv-qualifier-seq, check it now.
11087  if (Proto->hasTrailingReturn() &&
11088      !Finder.TraverseTypeLoc(ProtoTL->getResultLoc()))
11089    return true;
11090
11091  // Check the exception specification.
11092  if (checkThisInStaticMemberFunctionExceptionSpec(Method))
11093    return true;
11094
11095  return checkThisInStaticMemberFunctionAttributes(Method);
11096}
11097
11098bool Sema::checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl *Method) {
11099  TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
11100  if (!TSInfo)
11101    return false;
11102
11103  TypeLoc TL = TSInfo->getTypeLoc();
11104  FunctionProtoTypeLoc *ProtoTL = dyn_cast<FunctionProtoTypeLoc>(&TL);
11105  if (!ProtoTL)
11106    return false;
11107
11108  const FunctionProtoType *Proto = ProtoTL->getTypePtr();
11109  FindCXXThisExpr Finder(*this);
11110
11111  switch (Proto->getExceptionSpecType()) {
11112  case EST_Uninstantiated:
11113  case EST_Unevaluated:
11114  case EST_BasicNoexcept:
11115  case EST_DynamicNone:
11116  case EST_MSAny:
11117  case EST_None:
11118    break;
11119
11120  case EST_ComputedNoexcept:
11121    if (!Finder.TraverseStmt(Proto->getNoexceptExpr()))
11122      return true;
11123
11124  case EST_Dynamic:
11125    for (FunctionProtoType::exception_iterator E = Proto->exception_begin(),
11126         EEnd = Proto->exception_end();
11127         E != EEnd; ++E) {
11128      if (!Finder.TraverseType(*E))
11129        return true;
11130    }
11131    break;
11132  }
11133
11134  return false;
11135}
11136
11137bool Sema::checkThisInStaticMemberFunctionAttributes(CXXMethodDecl *Method) {
11138  FindCXXThisExpr Finder(*this);
11139
11140  // Check attributes.
11141  for (Decl::attr_iterator A = Method->attr_begin(), AEnd = Method->attr_end();
11142       A != AEnd; ++A) {
11143    // FIXME: This should be emitted by tblgen.
11144    Expr *Arg = 0;
11145    ArrayRef<Expr *> Args;
11146    if (GuardedByAttr *G = dyn_cast<GuardedByAttr>(*A))
11147      Arg = G->getArg();
11148    else if (PtGuardedByAttr *G = dyn_cast<PtGuardedByAttr>(*A))
11149      Arg = G->getArg();
11150    else if (AcquiredAfterAttr *AA = dyn_cast<AcquiredAfterAttr>(*A))
11151      Args = ArrayRef<Expr *>(AA->args_begin(), AA->args_size());
11152    else if (AcquiredBeforeAttr *AB = dyn_cast<AcquiredBeforeAttr>(*A))
11153      Args = ArrayRef<Expr *>(AB->args_begin(), AB->args_size());
11154    else if (ExclusiveLockFunctionAttr *ELF
11155               = dyn_cast<ExclusiveLockFunctionAttr>(*A))
11156      Args = ArrayRef<Expr *>(ELF->args_begin(), ELF->args_size());
11157    else if (SharedLockFunctionAttr *SLF
11158               = dyn_cast<SharedLockFunctionAttr>(*A))
11159      Args = ArrayRef<Expr *>(SLF->args_begin(), SLF->args_size());
11160    else if (ExclusiveTrylockFunctionAttr *ETLF
11161               = dyn_cast<ExclusiveTrylockFunctionAttr>(*A)) {
11162      Arg = ETLF->getSuccessValue();
11163      Args = ArrayRef<Expr *>(ETLF->args_begin(), ETLF->args_size());
11164    } else if (SharedTrylockFunctionAttr *STLF
11165                 = dyn_cast<SharedTrylockFunctionAttr>(*A)) {
11166      Arg = STLF->getSuccessValue();
11167      Args = ArrayRef<Expr *>(STLF->args_begin(), STLF->args_size());
11168    } else if (UnlockFunctionAttr *UF = dyn_cast<UnlockFunctionAttr>(*A))
11169      Args = ArrayRef<Expr *>(UF->args_begin(), UF->args_size());
11170    else if (LockReturnedAttr *LR = dyn_cast<LockReturnedAttr>(*A))
11171      Arg = LR->getArg();
11172    else if (LocksExcludedAttr *LE = dyn_cast<LocksExcludedAttr>(*A))
11173      Args = ArrayRef<Expr *>(LE->args_begin(), LE->args_size());
11174    else if (ExclusiveLocksRequiredAttr *ELR
11175               = dyn_cast<ExclusiveLocksRequiredAttr>(*A))
11176      Args = ArrayRef<Expr *>(ELR->args_begin(), ELR->args_size());
11177    else if (SharedLocksRequiredAttr *SLR
11178               = dyn_cast<SharedLocksRequiredAttr>(*A))
11179      Args = ArrayRef<Expr *>(SLR->args_begin(), SLR->args_size());
11180
11181    if (Arg && !Finder.TraverseStmt(Arg))
11182      return true;
11183
11184    for (unsigned I = 0, N = Args.size(); I != N; ++I) {
11185      if (!Finder.TraverseStmt(Args[I]))
11186        return true;
11187    }
11188  }
11189
11190  return false;
11191}
11192
11193void
11194Sema::checkExceptionSpecification(ExceptionSpecificationType EST,
11195                                  ArrayRef<ParsedType> DynamicExceptions,
11196                                  ArrayRef<SourceRange> DynamicExceptionRanges,
11197                                  Expr *NoexceptExpr,
11198                                  llvm::SmallVectorImpl<QualType> &Exceptions,
11199                                  FunctionProtoType::ExtProtoInfo &EPI) {
11200  Exceptions.clear();
11201  EPI.ExceptionSpecType = EST;
11202  if (EST == EST_Dynamic) {
11203    Exceptions.reserve(DynamicExceptions.size());
11204    for (unsigned ei = 0, ee = DynamicExceptions.size(); ei != ee; ++ei) {
11205      // FIXME: Preserve type source info.
11206      QualType ET = GetTypeFromParser(DynamicExceptions[ei]);
11207
11208      SmallVector<UnexpandedParameterPack, 2> Unexpanded;
11209      collectUnexpandedParameterPacks(ET, Unexpanded);
11210      if (!Unexpanded.empty()) {
11211        DiagnoseUnexpandedParameterPacks(DynamicExceptionRanges[ei].getBegin(),
11212                                         UPPC_ExceptionType,
11213                                         Unexpanded);
11214        continue;
11215      }
11216
11217      // Check that the type is valid for an exception spec, and
11218      // drop it if not.
11219      if (!CheckSpecifiedExceptionType(ET, DynamicExceptionRanges[ei]))
11220        Exceptions.push_back(ET);
11221    }
11222    EPI.NumExceptions = Exceptions.size();
11223    EPI.Exceptions = Exceptions.data();
11224    return;
11225  }
11226
11227  if (EST == EST_ComputedNoexcept) {
11228    // If an error occurred, there's no expression here.
11229    if (NoexceptExpr) {
11230      assert((NoexceptExpr->isTypeDependent() ||
11231              NoexceptExpr->getType()->getCanonicalTypeUnqualified() ==
11232              Context.BoolTy) &&
11233             "Parser should have made sure that the expression is boolean");
11234      if (NoexceptExpr && DiagnoseUnexpandedParameterPack(NoexceptExpr)) {
11235        EPI.ExceptionSpecType = EST_BasicNoexcept;
11236        return;
11237      }
11238
11239      if (!NoexceptExpr->isValueDependent())
11240        NoexceptExpr = VerifyIntegerConstantExpression(NoexceptExpr, 0,
11241                         diag::err_noexcept_needs_constant_expression,
11242                         /*AllowFold*/ false).take();
11243      EPI.NoexceptExpr = NoexceptExpr;
11244    }
11245    return;
11246  }
11247}
11248
11249/// IdentifyCUDATarget - Determine the CUDA compilation target for this function
11250Sema::CUDAFunctionTarget Sema::IdentifyCUDATarget(const FunctionDecl *D) {
11251  // Implicitly declared functions (e.g. copy constructors) are
11252  // __host__ __device__
11253  if (D->isImplicit())
11254    return CFT_HostDevice;
11255
11256  if (D->hasAttr<CUDAGlobalAttr>())
11257    return CFT_Global;
11258
11259  if (D->hasAttr<CUDADeviceAttr>()) {
11260    if (D->hasAttr<CUDAHostAttr>())
11261      return CFT_HostDevice;
11262    else
11263      return CFT_Device;
11264  }
11265
11266  return CFT_Host;
11267}
11268
11269bool Sema::CheckCUDATarget(CUDAFunctionTarget CallerTarget,
11270                           CUDAFunctionTarget CalleeTarget) {
11271  // CUDA B.1.1 "The __device__ qualifier declares a function that is...
11272  // Callable from the device only."
11273  if (CallerTarget == CFT_Host && CalleeTarget == CFT_Device)
11274    return true;
11275
11276  // CUDA B.1.2 "The __global__ qualifier declares a function that is...
11277  // Callable from the host only."
11278  // CUDA B.1.3 "The __host__ qualifier declares a function that is...
11279  // Callable from the host only."
11280  if ((CallerTarget == CFT_Device || CallerTarget == CFT_Global) &&
11281      (CalleeTarget == CFT_Host || CalleeTarget == CFT_Global))
11282    return true;
11283
11284  if (CallerTarget == CFT_HostDevice && CalleeTarget != CFT_HostDevice)
11285    return true;
11286
11287  return false;
11288}
11289