SemaDeclCXX.cpp revision d3861ce75a308c65b58c0159e2cee58aea2dff1c
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/ExprCXX.h"
27#include "clang/AST/RecordLayout.h"
28#include "clang/AST/RecursiveASTVisitor.h"
29#include "clang/AST/StmtVisitor.h"
30#include "clang/AST/TypeLoc.h"
31#include "clang/AST/TypeOrdering.h"
32#include "clang/Sema/DeclSpec.h"
33#include "clang/Sema/ParsedTemplate.h"
34#include "clang/Basic/PartialDiagnostic.h"
35#include "clang/Lex/Preprocessor.h"
36#include "llvm/ADT/SmallString.h"
37#include "llvm/ADT/STLExtras.h"
38#include <map>
39#include <set>
40
41using namespace clang;
42
43//===----------------------------------------------------------------------===//
44// CheckDefaultArgumentVisitor
45//===----------------------------------------------------------------------===//
46
47namespace {
48  /// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
49  /// the default argument of a parameter to determine whether it
50  /// contains any ill-formed subexpressions. For example, this will
51  /// diagnose the use of local variables or parameters within the
52  /// default argument expression.
53  class CheckDefaultArgumentVisitor
54    : public StmtVisitor<CheckDefaultArgumentVisitor, bool> {
55    Expr *DefaultArg;
56    Sema *S;
57
58  public:
59    CheckDefaultArgumentVisitor(Expr *defarg, Sema *s)
60      : DefaultArg(defarg), S(s) {}
61
62    bool VisitExpr(Expr *Node);
63    bool VisitDeclRefExpr(DeclRefExpr *DRE);
64    bool VisitCXXThisExpr(CXXThisExpr *ThisE);
65    bool VisitLambdaExpr(LambdaExpr *Lambda);
66  };
67
68  /// VisitExpr - Visit all of the children of this expression.
69  bool CheckDefaultArgumentVisitor::VisitExpr(Expr *Node) {
70    bool IsInvalid = false;
71    for (Stmt::child_range I = Node->children(); I; ++I)
72      IsInvalid |= Visit(*I);
73    return IsInvalid;
74  }
75
76  /// VisitDeclRefExpr - Visit a reference to a declaration, to
77  /// determine whether this declaration can be used in the default
78  /// argument expression.
79  bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(DeclRefExpr *DRE) {
80    NamedDecl *Decl = DRE->getDecl();
81    if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Decl)) {
82      // C++ [dcl.fct.default]p9
83      //   Default arguments are evaluated each time the function is
84      //   called. The order of evaluation of function arguments is
85      //   unspecified. Consequently, parameters of a function shall not
86      //   be used in default argument expressions, even if they are not
87      //   evaluated. Parameters of a function declared before a default
88      //   argument expression are in scope and can hide namespace and
89      //   class member names.
90      return S->Diag(DRE->getLocStart(),
91                     diag::err_param_default_argument_references_param)
92         << Param->getDeclName() << DefaultArg->getSourceRange();
93    } else if (VarDecl *VDecl = dyn_cast<VarDecl>(Decl)) {
94      // C++ [dcl.fct.default]p7
95      //   Local variables shall not be used in default argument
96      //   expressions.
97      if (VDecl->isLocalVarDecl())
98        return S->Diag(DRE->getLocStart(),
99                       diag::err_param_default_argument_references_local)
100          << VDecl->getDeclName() << DefaultArg->getSourceRange();
101    }
102
103    return false;
104  }
105
106  /// VisitCXXThisExpr - Visit a C++ "this" expression.
107  bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(CXXThisExpr *ThisE) {
108    // C++ [dcl.fct.default]p8:
109    //   The keyword this shall not be used in a default argument of a
110    //   member function.
111    return S->Diag(ThisE->getLocStart(),
112                   diag::err_param_default_argument_references_this)
113               << ThisE->getSourceRange();
114  }
115
116  bool CheckDefaultArgumentVisitor::VisitLambdaExpr(LambdaExpr *Lambda) {
117    // C++11 [expr.lambda.prim]p13:
118    //   A lambda-expression appearing in a default argument shall not
119    //   implicitly or explicitly capture any entity.
120    if (Lambda->capture_begin() == Lambda->capture_end())
121      return false;
122
123    return S->Diag(Lambda->getLocStart(),
124                   diag::err_lambda_capture_default_arg);
125  }
126}
127
128void Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc,
129                                                      CXXMethodDecl *Method) {
130  // If we have an MSAny or unknown spec already, don't bother.
131  if (!Method || ComputedEST == EST_MSAny || ComputedEST == EST_Delayed)
132    return;
133
134  const FunctionProtoType *Proto
135    = Method->getType()->getAs<FunctionProtoType>();
136  Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
137  if (!Proto)
138    return;
139
140  ExceptionSpecificationType EST = Proto->getExceptionSpecType();
141
142  // If this function can throw any exceptions, make a note of that.
143  if (EST == EST_Delayed || EST == EST_MSAny || EST == EST_None) {
144    ClearExceptions();
145    ComputedEST = EST;
146    return;
147  }
148
149  // FIXME: If the call to this decl is using any of its default arguments, we
150  // need to search them for potentially-throwing calls.
151
152  // If this function has a basic noexcept, it doesn't affect the outcome.
153  if (EST == EST_BasicNoexcept)
154    return;
155
156  // If we have a throw-all spec at this point, ignore the function.
157  if (ComputedEST == EST_None)
158    return;
159
160  // If we're still at noexcept(true) and there's a nothrow() callee,
161  // change to that specification.
162  if (EST == EST_DynamicNone) {
163    if (ComputedEST == EST_BasicNoexcept)
164      ComputedEST = EST_DynamicNone;
165    return;
166  }
167
168  // Check out noexcept specs.
169  if (EST == EST_ComputedNoexcept) {
170    FunctionProtoType::NoexceptResult NR =
171        Proto->getNoexceptSpec(Self->Context);
172    assert(NR != FunctionProtoType::NR_NoNoexcept &&
173           "Must have noexcept result for EST_ComputedNoexcept.");
174    assert(NR != FunctionProtoType::NR_Dependent &&
175           "Should not generate implicit declarations for dependent cases, "
176           "and don't know how to handle them anyway.");
177
178    // noexcept(false) -> no spec on the new function
179    if (NR == FunctionProtoType::NR_Throw) {
180      ClearExceptions();
181      ComputedEST = EST_None;
182    }
183    // noexcept(true) won't change anything either.
184    return;
185  }
186
187  assert(EST == EST_Dynamic && "EST case not considered earlier.");
188  assert(ComputedEST != EST_None &&
189         "Shouldn't collect exceptions when throw-all is guaranteed.");
190  ComputedEST = EST_Dynamic;
191  // Record the exceptions in this function's exception specification.
192  for (FunctionProtoType::exception_iterator E = Proto->exception_begin(),
193                                          EEnd = Proto->exception_end();
194       E != EEnd; ++E)
195    if (ExceptionsSeen.insert(Self->Context.getCanonicalType(*E)))
196      Exceptions.push_back(*E);
197}
198
199void Sema::ImplicitExceptionSpecification::CalledExpr(Expr *E) {
200  if (!E || ComputedEST == EST_MSAny || ComputedEST == EST_Delayed)
201    return;
202
203  // FIXME:
204  //
205  // C++0x [except.spec]p14:
206  //   [An] implicit exception-specification specifies the type-id T if and
207  // only if T is allowed by the exception-specification of a function directly
208  // invoked by f's implicit definition; f shall allow all exceptions if any
209  // function it directly invokes allows all exceptions, and f shall allow no
210  // exceptions if every function it directly invokes allows no exceptions.
211  //
212  // Note in particular that if an implicit exception-specification is generated
213  // for a function containing a throw-expression, that specification can still
214  // be noexcept(true).
215  //
216  // Note also that 'directly invoked' is not defined in the standard, and there
217  // is no indication that we should only consider potentially-evaluated calls.
218  //
219  // Ultimately we should implement the intent of the standard: the exception
220  // specification should be the set of exceptions which can be thrown by the
221  // implicit definition. For now, we assume that any non-nothrow expression can
222  // throw any exception.
223
224  if (Self->canThrow(E))
225    ComputedEST = EST_None;
226}
227
228bool
229Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
230                              SourceLocation EqualLoc) {
231  if (RequireCompleteType(Param->getLocation(), Param->getType(),
232                          diag::err_typecheck_decl_incomplete_type)) {
233    Param->setInvalidDecl();
234    return true;
235  }
236
237  // C++ [dcl.fct.default]p5
238  //   A default argument expression is implicitly converted (clause
239  //   4) to the parameter type. The default argument expression has
240  //   the same semantic constraints as the initializer expression in
241  //   a declaration of a variable of the parameter type, using the
242  //   copy-initialization semantics (8.5).
243  InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
244                                                                    Param);
245  InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(),
246                                                           EqualLoc);
247  InitializationSequence InitSeq(*this, Entity, Kind, &Arg, 1);
248  ExprResult Result = InitSeq.Perform(*this, Entity, Kind,
249                                      MultiExprArg(*this, &Arg, 1));
250  if (Result.isInvalid())
251    return true;
252  Arg = Result.takeAs<Expr>();
253
254  CheckImplicitConversions(Arg, EqualLoc);
255  Arg = MaybeCreateExprWithCleanups(Arg);
256
257  // Okay: add the default argument to the parameter
258  Param->setDefaultArg(Arg);
259
260  // We have already instantiated this parameter; provide each of the
261  // instantiations with the uninstantiated default argument.
262  UnparsedDefaultArgInstantiationsMap::iterator InstPos
263    = UnparsedDefaultArgInstantiations.find(Param);
264  if (InstPos != UnparsedDefaultArgInstantiations.end()) {
265    for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
266      InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
267
268    // We're done tracking this parameter's instantiations.
269    UnparsedDefaultArgInstantiations.erase(InstPos);
270  }
271
272  return false;
273}
274
275/// ActOnParamDefaultArgument - Check whether the default argument
276/// provided for a function parameter is well-formed. If so, attach it
277/// to the parameter declaration.
278void
279Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc,
280                                Expr *DefaultArg) {
281  if (!param || !DefaultArg)
282    return;
283
284  ParmVarDecl *Param = cast<ParmVarDecl>(param);
285  UnparsedDefaultArgLocs.erase(Param);
286
287  // Default arguments are only permitted in C++
288  if (!getLangOpts().CPlusPlus) {
289    Diag(EqualLoc, diag::err_param_default_argument)
290      << DefaultArg->getSourceRange();
291    Param->setInvalidDecl();
292    return;
293  }
294
295  // Check for unexpanded parameter packs.
296  if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
297    Param->setInvalidDecl();
298    return;
299  }
300
301  // Check that the default argument is well-formed
302  CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg, this);
303  if (DefaultArgChecker.Visit(DefaultArg)) {
304    Param->setInvalidDecl();
305    return;
306  }
307
308  SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
309}
310
311/// ActOnParamUnparsedDefaultArgument - We've seen a default
312/// argument for a function parameter, but we can't parse it yet
313/// because we're inside a class definition. Note that this default
314/// argument will be parsed later.
315void Sema::ActOnParamUnparsedDefaultArgument(Decl *param,
316                                             SourceLocation EqualLoc,
317                                             SourceLocation ArgLoc) {
318  if (!param)
319    return;
320
321  ParmVarDecl *Param = cast<ParmVarDecl>(param);
322  if (Param)
323    Param->setUnparsedDefaultArg();
324
325  UnparsedDefaultArgLocs[Param] = ArgLoc;
326}
327
328/// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
329/// the default argument for the parameter param failed.
330void Sema::ActOnParamDefaultArgumentError(Decl *param) {
331  if (!param)
332    return;
333
334  ParmVarDecl *Param = cast<ParmVarDecl>(param);
335
336  Param->setInvalidDecl();
337
338  UnparsedDefaultArgLocs.erase(Param);
339}
340
341/// CheckExtraCXXDefaultArguments - Check for any extra default
342/// arguments in the declarator, which is not a function declaration
343/// or definition and therefore is not permitted to have default
344/// arguments. This routine should be invoked for every declarator
345/// that is not a function declaration or definition.
346void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
347  // C++ [dcl.fct.default]p3
348  //   A default argument expression shall be specified only in the
349  //   parameter-declaration-clause of a function declaration or in a
350  //   template-parameter (14.1). It shall not be specified for a
351  //   parameter pack. If it is specified in a
352  //   parameter-declaration-clause, it shall not occur within a
353  //   declarator or abstract-declarator of a parameter-declaration.
354  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
355    DeclaratorChunk &chunk = D.getTypeObject(i);
356    if (chunk.Kind == DeclaratorChunk::Function) {
357      for (unsigned argIdx = 0, e = chunk.Fun.NumArgs; argIdx != e; ++argIdx) {
358        ParmVarDecl *Param =
359          cast<ParmVarDecl>(chunk.Fun.ArgInfo[argIdx].Param);
360        if (Param->hasUnparsedDefaultArg()) {
361          CachedTokens *Toks = chunk.Fun.ArgInfo[argIdx].DefaultArgTokens;
362          Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
363            << SourceRange((*Toks)[1].getLocation(), Toks->back().getLocation());
364          delete Toks;
365          chunk.Fun.ArgInfo[argIdx].DefaultArgTokens = 0;
366        } else if (Param->getDefaultArg()) {
367          Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
368            << Param->getDefaultArg()->getSourceRange();
369          Param->setDefaultArg(0);
370        }
371      }
372    }
373  }
374}
375
376// MergeCXXFunctionDecl - Merge two declarations of the same C++
377// function, once we already know that they have the same
378// type. Subroutine of MergeFunctionDecl. Returns true if there was an
379// error, false otherwise.
380bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old,
381                                Scope *S) {
382  bool Invalid = false;
383
384  // C++ [dcl.fct.default]p4:
385  //   For non-template functions, default arguments can be added in
386  //   later declarations of a function in the same
387  //   scope. Declarations in different scopes have completely
388  //   distinct sets of default arguments. That is, declarations in
389  //   inner scopes do not acquire default arguments from
390  //   declarations in outer scopes, and vice versa. In a given
391  //   function declaration, all parameters subsequent to a
392  //   parameter with a default argument shall have default
393  //   arguments supplied in this or previous declarations. A
394  //   default argument shall not be redefined by a later
395  //   declaration (not even to the same value).
396  //
397  // C++ [dcl.fct.default]p6:
398  //   Except for member functions of class templates, the default arguments
399  //   in a member function definition that appears outside of the class
400  //   definition are added to the set of default arguments provided by the
401  //   member function declaration in the class definition.
402  for (unsigned p = 0, NumParams = Old->getNumParams(); p < NumParams; ++p) {
403    ParmVarDecl *OldParam = Old->getParamDecl(p);
404    ParmVarDecl *NewParam = New->getParamDecl(p);
405
406    bool OldParamHasDfl = OldParam->hasDefaultArg();
407    bool NewParamHasDfl = NewParam->hasDefaultArg();
408
409    NamedDecl *ND = Old;
410    if (S && !isDeclInScope(ND, New->getDeclContext(), S))
411      // Ignore default parameters of old decl if they are not in
412      // the same scope.
413      OldParamHasDfl = false;
414
415    if (OldParamHasDfl && NewParamHasDfl) {
416
417      unsigned DiagDefaultParamID =
418        diag::err_param_default_argument_redefinition;
419
420      // MSVC accepts that default parameters be redefined for member functions
421      // of template class. The new default parameter's value is ignored.
422      Invalid = true;
423      if (getLangOpts().MicrosoftExt) {
424        CXXMethodDecl* MD = dyn_cast<CXXMethodDecl>(New);
425        if (MD && MD->getParent()->getDescribedClassTemplate()) {
426          // Merge the old default argument into the new parameter.
427          NewParam->setHasInheritedDefaultArg();
428          if (OldParam->hasUninstantiatedDefaultArg())
429            NewParam->setUninstantiatedDefaultArg(
430                                      OldParam->getUninstantiatedDefaultArg());
431          else
432            NewParam->setDefaultArg(OldParam->getInit());
433          DiagDefaultParamID = diag::warn_param_default_argument_redefinition;
434          Invalid = false;
435        }
436      }
437
438      // FIXME: If we knew where the '=' was, we could easily provide a fix-it
439      // hint here. Alternatively, we could walk the type-source information
440      // for NewParam to find the last source location in the type... but it
441      // isn't worth the effort right now. This is the kind of test case that
442      // is hard to get right:
443      //   int f(int);
444      //   void g(int (*fp)(int) = f);
445      //   void g(int (*fp)(int) = &f);
446      Diag(NewParam->getLocation(), DiagDefaultParamID)
447        << NewParam->getDefaultArgRange();
448
449      // Look for the function declaration where the default argument was
450      // actually written, which may be a declaration prior to Old.
451      for (FunctionDecl *Older = Old->getPreviousDecl();
452           Older; Older = Older->getPreviousDecl()) {
453        if (!Older->getParamDecl(p)->hasDefaultArg())
454          break;
455
456        OldParam = Older->getParamDecl(p);
457      }
458
459      Diag(OldParam->getLocation(), diag::note_previous_definition)
460        << OldParam->getDefaultArgRange();
461    } else if (OldParamHasDfl) {
462      // Merge the old default argument into the new parameter.
463      // It's important to use getInit() here;  getDefaultArg()
464      // strips off any top-level ExprWithCleanups.
465      NewParam->setHasInheritedDefaultArg();
466      if (OldParam->hasUninstantiatedDefaultArg())
467        NewParam->setUninstantiatedDefaultArg(
468                                      OldParam->getUninstantiatedDefaultArg());
469      else
470        NewParam->setDefaultArg(OldParam->getInit());
471    } else if (NewParamHasDfl) {
472      if (New->getDescribedFunctionTemplate()) {
473        // Paragraph 4, quoted above, only applies to non-template functions.
474        Diag(NewParam->getLocation(),
475             diag::err_param_default_argument_template_redecl)
476          << NewParam->getDefaultArgRange();
477        Diag(Old->getLocation(), diag::note_template_prev_declaration)
478          << false;
479      } else if (New->getTemplateSpecializationKind()
480                   != TSK_ImplicitInstantiation &&
481                 New->getTemplateSpecializationKind() != TSK_Undeclared) {
482        // C++ [temp.expr.spec]p21:
483        //   Default function arguments shall not be specified in a declaration
484        //   or a definition for one of the following explicit specializations:
485        //     - the explicit specialization of a function template;
486        //     - the explicit specialization of a member function template;
487        //     - the explicit specialization of a member function of a class
488        //       template where the class template specialization to which the
489        //       member function specialization belongs is implicitly
490        //       instantiated.
491        Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
492          << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
493          << New->getDeclName()
494          << NewParam->getDefaultArgRange();
495      } else if (New->getDeclContext()->isDependentContext()) {
496        // C++ [dcl.fct.default]p6 (DR217):
497        //   Default arguments for a member function of a class template shall
498        //   be specified on the initial declaration of the member function
499        //   within the class template.
500        //
501        // Reading the tea leaves a bit in DR217 and its reference to DR205
502        // leads me to the conclusion that one cannot add default function
503        // arguments for an out-of-line definition of a member function of a
504        // dependent type.
505        int WhichKind = 2;
506        if (CXXRecordDecl *Record
507              = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
508          if (Record->getDescribedClassTemplate())
509            WhichKind = 0;
510          else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
511            WhichKind = 1;
512          else
513            WhichKind = 2;
514        }
515
516        Diag(NewParam->getLocation(),
517             diag::err_param_default_argument_member_template_redecl)
518          << WhichKind
519          << NewParam->getDefaultArgRange();
520      } else if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(New)) {
521        CXXSpecialMember NewSM = getSpecialMember(Ctor),
522                         OldSM = getSpecialMember(cast<CXXConstructorDecl>(Old));
523        if (NewSM != OldSM) {
524          Diag(NewParam->getLocation(),diag::warn_default_arg_makes_ctor_special)
525            << NewParam->getDefaultArgRange() << NewSM;
526          Diag(Old->getLocation(), diag::note_previous_declaration_special)
527            << OldSM;
528        }
529      }
530    }
531  }
532
533  // C++11 [dcl.constexpr]p1: If any declaration of a function or function
534  // template has a constexpr specifier then all its declarations shall
535  // contain the constexpr specifier.
536  if (New->isConstexpr() != Old->isConstexpr()) {
537    Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
538      << New << New->isConstexpr();
539    Diag(Old->getLocation(), diag::note_previous_declaration);
540    Invalid = true;
541  }
542
543  if (CheckEquivalentExceptionSpec(Old, New))
544    Invalid = true;
545
546  return Invalid;
547}
548
549/// \brief Merge the exception specifications of two variable declarations.
550///
551/// This is called when there's a redeclaration of a VarDecl. The function
552/// checks if the redeclaration might have an exception specification and
553/// validates compatibility and merges the specs if necessary.
554void Sema::MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old) {
555  // Shortcut if exceptions are disabled.
556  if (!getLangOpts().CXXExceptions)
557    return;
558
559  assert(Context.hasSameType(New->getType(), Old->getType()) &&
560         "Should only be called if types are otherwise the same.");
561
562  QualType NewType = New->getType();
563  QualType OldType = Old->getType();
564
565  // We're only interested in pointers and references to functions, as well
566  // as pointers to member functions.
567  if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
568    NewType = R->getPointeeType();
569    OldType = OldType->getAs<ReferenceType>()->getPointeeType();
570  } else if (const PointerType *P = NewType->getAs<PointerType>()) {
571    NewType = P->getPointeeType();
572    OldType = OldType->getAs<PointerType>()->getPointeeType();
573  } else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
574    NewType = M->getPointeeType();
575    OldType = OldType->getAs<MemberPointerType>()->getPointeeType();
576  }
577
578  if (!NewType->isFunctionProtoType())
579    return;
580
581  // There's lots of special cases for functions. For function pointers, system
582  // libraries are hopefully not as broken so that we don't need these
583  // workarounds.
584  if (CheckEquivalentExceptionSpec(
585        OldType->getAs<FunctionProtoType>(), Old->getLocation(),
586        NewType->getAs<FunctionProtoType>(), New->getLocation())) {
587    New->setInvalidDecl();
588  }
589}
590
591/// CheckCXXDefaultArguments - Verify that the default arguments for a
592/// function declaration are well-formed according to C++
593/// [dcl.fct.default].
594void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
595  unsigned NumParams = FD->getNumParams();
596  unsigned p;
597
598  bool IsLambda = FD->getOverloadedOperator() == OO_Call &&
599                  isa<CXXMethodDecl>(FD) &&
600                  cast<CXXMethodDecl>(FD)->getParent()->isLambda();
601
602  // Find first parameter with a default argument
603  for (p = 0; p < NumParams; ++p) {
604    ParmVarDecl *Param = FD->getParamDecl(p);
605    if (Param->hasDefaultArg()) {
606      // C++11 [expr.prim.lambda]p5:
607      //   [...] Default arguments (8.3.6) shall not be specified in the
608      //   parameter-declaration-clause of a lambda-declarator.
609      //
610      // FIXME: Core issue 974 strikes this sentence, we only provide an
611      // extension warning.
612      if (IsLambda)
613        Diag(Param->getLocation(), diag::ext_lambda_default_arguments)
614          << Param->getDefaultArgRange();
615      break;
616    }
617  }
618
619  // C++ [dcl.fct.default]p4:
620  //   In a given function declaration, all parameters
621  //   subsequent to a parameter with a default argument shall
622  //   have default arguments supplied in this or previous
623  //   declarations. A default argument shall not be redefined
624  //   by a later declaration (not even to the same value).
625  unsigned LastMissingDefaultArg = 0;
626  for (; p < NumParams; ++p) {
627    ParmVarDecl *Param = FD->getParamDecl(p);
628    if (!Param->hasDefaultArg()) {
629      if (Param->isInvalidDecl())
630        /* We already complained about this parameter. */;
631      else if (Param->getIdentifier())
632        Diag(Param->getLocation(),
633             diag::err_param_default_argument_missing_name)
634          << Param->getIdentifier();
635      else
636        Diag(Param->getLocation(),
637             diag::err_param_default_argument_missing);
638
639      LastMissingDefaultArg = p;
640    }
641  }
642
643  if (LastMissingDefaultArg > 0) {
644    // Some default arguments were missing. Clear out all of the
645    // default arguments up to (and including) the last missing
646    // default argument, so that we leave the function parameters
647    // in a semantically valid state.
648    for (p = 0; p <= LastMissingDefaultArg; ++p) {
649      ParmVarDecl *Param = FD->getParamDecl(p);
650      if (Param->hasDefaultArg()) {
651        Param->setDefaultArg(0);
652      }
653    }
654  }
655}
656
657// CheckConstexprParameterTypes - Check whether a function's parameter types
658// are all literal types. If so, return true. If not, produce a suitable
659// diagnostic and return false.
660static bool CheckConstexprParameterTypes(Sema &SemaRef,
661                                         const FunctionDecl *FD) {
662  unsigned ArgIndex = 0;
663  const FunctionProtoType *FT = FD->getType()->getAs<FunctionProtoType>();
664  for (FunctionProtoType::arg_type_iterator i = FT->arg_type_begin(),
665       e = FT->arg_type_end(); i != e; ++i, ++ArgIndex) {
666    const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
667    SourceLocation ParamLoc = PD->getLocation();
668    if (!(*i)->isDependentType() &&
669        SemaRef.RequireLiteralType(ParamLoc, *i,
670                                   diag::err_constexpr_non_literal_param,
671                                   ArgIndex+1, PD->getSourceRange(),
672                                   isa<CXXConstructorDecl>(FD)))
673      return false;
674  }
675  return true;
676}
677
678// CheckConstexprFunctionDecl - Check whether a function declaration satisfies
679// the requirements of a constexpr function definition or a constexpr
680// constructor definition. If so, return true. If not, produce appropriate
681// diagnostics and return false.
682//
683// This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
684bool Sema::CheckConstexprFunctionDecl(const FunctionDecl *NewFD) {
685  const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
686  if (MD && MD->isInstance()) {
687    // C++11 [dcl.constexpr]p4:
688    //  The definition of a constexpr constructor shall satisfy the following
689    //  constraints:
690    //  - the class shall not have any virtual base classes;
691    const CXXRecordDecl *RD = MD->getParent();
692    if (RD->getNumVBases()) {
693      Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
694        << isa<CXXConstructorDecl>(NewFD) << RD->isStruct()
695        << RD->getNumVBases();
696      for (CXXRecordDecl::base_class_const_iterator I = RD->vbases_begin(),
697             E = RD->vbases_end(); I != E; ++I)
698        Diag(I->getLocStart(),
699             diag::note_constexpr_virtual_base_here) << I->getSourceRange();
700      return false;
701    }
702  }
703
704  if (!isa<CXXConstructorDecl>(NewFD)) {
705    // C++11 [dcl.constexpr]p3:
706    //  The definition of a constexpr function shall satisfy the following
707    //  constraints:
708    // - it shall not be virtual;
709    const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
710    if (Method && Method->isVirtual()) {
711      Diag(NewFD->getLocation(), diag::err_constexpr_virtual);
712
713      // If it's not obvious why this function is virtual, find an overridden
714      // function which uses the 'virtual' keyword.
715      const CXXMethodDecl *WrittenVirtual = Method;
716      while (!WrittenVirtual->isVirtualAsWritten())
717        WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
718      if (WrittenVirtual != Method)
719        Diag(WrittenVirtual->getLocation(),
720             diag::note_overridden_virtual_function);
721      return false;
722    }
723
724    // - its return type shall be a literal type;
725    QualType RT = NewFD->getResultType();
726    if (!RT->isDependentType() &&
727        RequireLiteralType(NewFD->getLocation(), RT,
728                           diag::err_constexpr_non_literal_return))
729      return false;
730  }
731
732  // - each of its parameter types shall be a literal type;
733  if (!CheckConstexprParameterTypes(*this, NewFD))
734    return false;
735
736  return true;
737}
738
739/// Check the given declaration statement is legal within a constexpr function
740/// body. C++0x [dcl.constexpr]p3,p4.
741///
742/// \return true if the body is OK, false if we have diagnosed a problem.
743static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
744                                   DeclStmt *DS) {
745  // C++0x [dcl.constexpr]p3 and p4:
746  //  The definition of a constexpr function(p3) or constructor(p4) [...] shall
747  //  contain only
748  for (DeclStmt::decl_iterator DclIt = DS->decl_begin(),
749         DclEnd = DS->decl_end(); DclIt != DclEnd; ++DclIt) {
750    switch ((*DclIt)->getKind()) {
751    case Decl::StaticAssert:
752    case Decl::Using:
753    case Decl::UsingShadow:
754    case Decl::UsingDirective:
755    case Decl::UnresolvedUsingTypename:
756      //   - static_assert-declarations
757      //   - using-declarations,
758      //   - using-directives,
759      continue;
760
761    case Decl::Typedef:
762    case Decl::TypeAlias: {
763      //   - typedef declarations and alias-declarations that do not define
764      //     classes or enumerations,
765      TypedefNameDecl *TN = cast<TypedefNameDecl>(*DclIt);
766      if (TN->getUnderlyingType()->isVariablyModifiedType()) {
767        // Don't allow variably-modified types in constexpr functions.
768        TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
769        SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
770          << TL.getSourceRange() << TL.getType()
771          << isa<CXXConstructorDecl>(Dcl);
772        return false;
773      }
774      continue;
775    }
776
777    case Decl::Enum:
778    case Decl::CXXRecord:
779      // As an extension, we allow the declaration (but not the definition) of
780      // classes and enumerations in all declarations, not just in typedef and
781      // alias declarations.
782      if (cast<TagDecl>(*DclIt)->isThisDeclarationADefinition()) {
783        SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_type_definition)
784          << isa<CXXConstructorDecl>(Dcl);
785        return false;
786      }
787      continue;
788
789    case Decl::Var:
790      SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_var_declaration)
791        << isa<CXXConstructorDecl>(Dcl);
792      return false;
793
794    default:
795      SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_body_invalid_stmt)
796        << isa<CXXConstructorDecl>(Dcl);
797      return false;
798    }
799  }
800
801  return true;
802}
803
804/// Check that the given field is initialized within a constexpr constructor.
805///
806/// \param Dcl The constexpr constructor being checked.
807/// \param Field The field being checked. This may be a member of an anonymous
808///        struct or union nested within the class being checked.
809/// \param Inits All declarations, including anonymous struct/union members and
810///        indirect members, for which any initialization was provided.
811/// \param Diagnosed Set to true if an error is produced.
812static void CheckConstexprCtorInitializer(Sema &SemaRef,
813                                          const FunctionDecl *Dcl,
814                                          FieldDecl *Field,
815                                          llvm::SmallSet<Decl*, 16> &Inits,
816                                          bool &Diagnosed) {
817  if (Field->isUnnamedBitfield())
818    return;
819
820  if (Field->isAnonymousStructOrUnion() &&
821      Field->getType()->getAsCXXRecordDecl()->isEmpty())
822    return;
823
824  if (!Inits.count(Field)) {
825    if (!Diagnosed) {
826      SemaRef.Diag(Dcl->getLocation(), diag::err_constexpr_ctor_missing_init);
827      Diagnosed = true;
828    }
829    SemaRef.Diag(Field->getLocation(), diag::note_constexpr_ctor_missing_init);
830  } else if (Field->isAnonymousStructOrUnion()) {
831    const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
832    for (RecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end();
833         I != E; ++I)
834      // If an anonymous union contains an anonymous struct of which any member
835      // is initialized, all members must be initialized.
836      if (!RD->isUnion() || Inits.count(*I))
837        CheckConstexprCtorInitializer(SemaRef, Dcl, *I, Inits, Diagnosed);
838  }
839}
840
841/// Check the body for the given constexpr function declaration only contains
842/// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
843///
844/// \return true if the body is OK, false if we have diagnosed a problem.
845bool Sema::CheckConstexprFunctionBody(const FunctionDecl *Dcl, Stmt *Body) {
846  if (isa<CXXTryStmt>(Body)) {
847    // C++11 [dcl.constexpr]p3:
848    //  The definition of a constexpr function shall satisfy the following
849    //  constraints: [...]
850    // - its function-body shall be = delete, = default, or a
851    //   compound-statement
852    //
853    // C++11 [dcl.constexpr]p4:
854    //  In the definition of a constexpr constructor, [...]
855    // - its function-body shall not be a function-try-block;
856    Diag(Body->getLocStart(), diag::err_constexpr_function_try_block)
857      << isa<CXXConstructorDecl>(Dcl);
858    return false;
859  }
860
861  // - its function-body shall be [...] a compound-statement that contains only
862  CompoundStmt *CompBody = cast<CompoundStmt>(Body);
863
864  llvm::SmallVector<SourceLocation, 4> ReturnStmts;
865  for (CompoundStmt::body_iterator BodyIt = CompBody->body_begin(),
866         BodyEnd = CompBody->body_end(); BodyIt != BodyEnd; ++BodyIt) {
867    switch ((*BodyIt)->getStmtClass()) {
868    case Stmt::NullStmtClass:
869      //   - null statements,
870      continue;
871
872    case Stmt::DeclStmtClass:
873      //   - static_assert-declarations
874      //   - using-declarations,
875      //   - using-directives,
876      //   - typedef declarations and alias-declarations that do not define
877      //     classes or enumerations,
878      if (!CheckConstexprDeclStmt(*this, Dcl, cast<DeclStmt>(*BodyIt)))
879        return false;
880      continue;
881
882    case Stmt::ReturnStmtClass:
883      //   - and exactly one return statement;
884      if (isa<CXXConstructorDecl>(Dcl))
885        break;
886
887      ReturnStmts.push_back((*BodyIt)->getLocStart());
888      continue;
889
890    default:
891      break;
892    }
893
894    Diag((*BodyIt)->getLocStart(), diag::err_constexpr_body_invalid_stmt)
895      << isa<CXXConstructorDecl>(Dcl);
896    return false;
897  }
898
899  if (const CXXConstructorDecl *Constructor
900        = dyn_cast<CXXConstructorDecl>(Dcl)) {
901    const CXXRecordDecl *RD = Constructor->getParent();
902    // DR1359:
903    // - every non-variant non-static data member and base class sub-object
904    //   shall be initialized;
905    // - if the class is a non-empty union, or for each non-empty anonymous
906    //   union member of a non-union class, exactly one non-static data member
907    //   shall be initialized;
908    if (RD->isUnion()) {
909      if (Constructor->getNumCtorInitializers() == 0 && !RD->isEmpty()) {
910        Diag(Dcl->getLocation(), diag::err_constexpr_union_ctor_no_init);
911        return false;
912      }
913    } else if (!Constructor->isDependentContext() &&
914               !Constructor->isDelegatingConstructor()) {
915      assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases");
916
917      // Skip detailed checking if we have enough initializers, and we would
918      // allow at most one initializer per member.
919      bool AnyAnonStructUnionMembers = false;
920      unsigned Fields = 0;
921      for (CXXRecordDecl::field_iterator I = RD->field_begin(),
922           E = RD->field_end(); I != E; ++I, ++Fields) {
923        if (I->isAnonymousStructOrUnion()) {
924          AnyAnonStructUnionMembers = true;
925          break;
926        }
927      }
928      if (AnyAnonStructUnionMembers ||
929          Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
930        // Check initialization of non-static data members. Base classes are
931        // always initialized so do not need to be checked. Dependent bases
932        // might not have initializers in the member initializer list.
933        llvm::SmallSet<Decl*, 16> Inits;
934        for (CXXConstructorDecl::init_const_iterator
935               I = Constructor->init_begin(), E = Constructor->init_end();
936             I != E; ++I) {
937          if (FieldDecl *FD = (*I)->getMember())
938            Inits.insert(FD);
939          else if (IndirectFieldDecl *ID = (*I)->getIndirectMember())
940            Inits.insert(ID->chain_begin(), ID->chain_end());
941        }
942
943        bool Diagnosed = false;
944        for (CXXRecordDecl::field_iterator I = RD->field_begin(),
945             E = RD->field_end(); I != E; ++I)
946          CheckConstexprCtorInitializer(*this, Dcl, *I, Inits, Diagnosed);
947        if (Diagnosed)
948          return false;
949      }
950    }
951  } else {
952    if (ReturnStmts.empty()) {
953      Diag(Dcl->getLocation(), diag::err_constexpr_body_no_return);
954      return false;
955    }
956    if (ReturnStmts.size() > 1) {
957      Diag(ReturnStmts.back(), diag::err_constexpr_body_multiple_return);
958      for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
959        Diag(ReturnStmts[I], diag::note_constexpr_body_previous_return);
960      return false;
961    }
962  }
963
964  // C++11 [dcl.constexpr]p5:
965  //   if no function argument values exist such that the function invocation
966  //   substitution would produce a constant expression, the program is
967  //   ill-formed; no diagnostic required.
968  // C++11 [dcl.constexpr]p3:
969  //   - every constructor call and implicit conversion used in initializing the
970  //     return value shall be one of those allowed in a constant expression.
971  // C++11 [dcl.constexpr]p4:
972  //   - every constructor involved in initializing non-static data members and
973  //     base class sub-objects shall be a constexpr constructor.
974  llvm::SmallVector<PartialDiagnosticAt, 8> Diags;
975  if (!Expr::isPotentialConstantExpr(Dcl, Diags)) {
976    Diag(Dcl->getLocation(), diag::err_constexpr_function_never_constant_expr)
977      << isa<CXXConstructorDecl>(Dcl);
978    for (size_t I = 0, N = Diags.size(); I != N; ++I)
979      Diag(Diags[I].first, Diags[I].second);
980    return false;
981  }
982
983  return true;
984}
985
986/// isCurrentClassName - Determine whether the identifier II is the
987/// name of the class type currently being defined. In the case of
988/// nested classes, this will only return true if II is the name of
989/// the innermost class.
990bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *,
991                              const CXXScopeSpec *SS) {
992  assert(getLangOpts().CPlusPlus && "No class names in C!");
993
994  CXXRecordDecl *CurDecl;
995  if (SS && SS->isSet() && !SS->isInvalid()) {
996    DeclContext *DC = computeDeclContext(*SS, true);
997    CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
998  } else
999    CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
1000
1001  if (CurDecl && CurDecl->getIdentifier())
1002    return &II == CurDecl->getIdentifier();
1003  else
1004    return false;
1005}
1006
1007/// \brief Check the validity of a C++ base class specifier.
1008///
1009/// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
1010/// and returns NULL otherwise.
1011CXXBaseSpecifier *
1012Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
1013                         SourceRange SpecifierRange,
1014                         bool Virtual, AccessSpecifier Access,
1015                         TypeSourceInfo *TInfo,
1016                         SourceLocation EllipsisLoc) {
1017  QualType BaseType = TInfo->getType();
1018
1019  // C++ [class.union]p1:
1020  //   A union shall not have base classes.
1021  if (Class->isUnion()) {
1022    Diag(Class->getLocation(), diag::err_base_clause_on_union)
1023      << SpecifierRange;
1024    return 0;
1025  }
1026
1027  if (EllipsisLoc.isValid() &&
1028      !TInfo->getType()->containsUnexpandedParameterPack()) {
1029    Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
1030      << TInfo->getTypeLoc().getSourceRange();
1031    EllipsisLoc = SourceLocation();
1032  }
1033
1034  if (BaseType->isDependentType())
1035    return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
1036                                          Class->getTagKind() == TTK_Class,
1037                                          Access, TInfo, EllipsisLoc);
1038
1039  SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
1040
1041  // Base specifiers must be record types.
1042  if (!BaseType->isRecordType()) {
1043    Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
1044    return 0;
1045  }
1046
1047  // C++ [class.union]p1:
1048  //   A union shall not be used as a base class.
1049  if (BaseType->isUnionType()) {
1050    Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
1051    return 0;
1052  }
1053
1054  // C++ [class.derived]p2:
1055  //   The class-name in a base-specifier shall not be an incompletely
1056  //   defined class.
1057  if (RequireCompleteType(BaseLoc, BaseType,
1058                          diag::err_incomplete_base_class, SpecifierRange)) {
1059    Class->setInvalidDecl();
1060    return 0;
1061  }
1062
1063  // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
1064  RecordDecl *BaseDecl = BaseType->getAs<RecordType>()->getDecl();
1065  assert(BaseDecl && "Record type has no declaration");
1066  BaseDecl = BaseDecl->getDefinition();
1067  assert(BaseDecl && "Base type is not incomplete, but has no definition");
1068  CXXRecordDecl * CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
1069  assert(CXXBaseDecl && "Base type is not a C++ type");
1070
1071  // C++ [class]p3:
1072  //   If a class is marked final and it appears as a base-type-specifier in
1073  //   base-clause, the program is ill-formed.
1074  if (CXXBaseDecl->hasAttr<FinalAttr>()) {
1075    Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
1076      << CXXBaseDecl->getDeclName();
1077    Diag(CXXBaseDecl->getLocation(), diag::note_previous_decl)
1078      << CXXBaseDecl->getDeclName();
1079    return 0;
1080  }
1081
1082  if (BaseDecl->isInvalidDecl())
1083    Class->setInvalidDecl();
1084
1085  // Create the base specifier.
1086  return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
1087                                        Class->getTagKind() == TTK_Class,
1088                                        Access, TInfo, EllipsisLoc);
1089}
1090
1091/// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
1092/// one entry in the base class list of a class specifier, for
1093/// example:
1094///    class foo : public bar, virtual private baz {
1095/// 'public bar' and 'virtual private baz' are each base-specifiers.
1096BaseResult
1097Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
1098                         bool Virtual, AccessSpecifier Access,
1099                         ParsedType basetype, SourceLocation BaseLoc,
1100                         SourceLocation EllipsisLoc) {
1101  if (!classdecl)
1102    return true;
1103
1104  AdjustDeclIfTemplate(classdecl);
1105  CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
1106  if (!Class)
1107    return true;
1108
1109  TypeSourceInfo *TInfo = 0;
1110  GetTypeFromParser(basetype, &TInfo);
1111
1112  if (EllipsisLoc.isInvalid() &&
1113      DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
1114                                      UPPC_BaseType))
1115    return true;
1116
1117  if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
1118                                                      Virtual, Access, TInfo,
1119                                                      EllipsisLoc))
1120    return BaseSpec;
1121
1122  return true;
1123}
1124
1125/// \brief Performs the actual work of attaching the given base class
1126/// specifiers to a C++ class.
1127bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class, CXXBaseSpecifier **Bases,
1128                                unsigned NumBases) {
1129 if (NumBases == 0)
1130    return false;
1131
1132  // Used to keep track of which base types we have already seen, so
1133  // that we can properly diagnose redundant direct base types. Note
1134  // that the key is always the unqualified canonical type of the base
1135  // class.
1136  std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
1137
1138  // Copy non-redundant base specifiers into permanent storage.
1139  unsigned NumGoodBases = 0;
1140  bool Invalid = false;
1141  for (unsigned idx = 0; idx < NumBases; ++idx) {
1142    QualType NewBaseType
1143      = Context.getCanonicalType(Bases[idx]->getType());
1144    NewBaseType = NewBaseType.getLocalUnqualifiedType();
1145
1146    CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
1147    if (KnownBase) {
1148      // C++ [class.mi]p3:
1149      //   A class shall not be specified as a direct base class of a
1150      //   derived class more than once.
1151      Diag(Bases[idx]->getLocStart(),
1152           diag::err_duplicate_base_class)
1153        << KnownBase->getType()
1154        << Bases[idx]->getSourceRange();
1155
1156      // Delete the duplicate base class specifier; we're going to
1157      // overwrite its pointer later.
1158      Context.Deallocate(Bases[idx]);
1159
1160      Invalid = true;
1161    } else {
1162      // Okay, add this new base class.
1163      KnownBase = Bases[idx];
1164      Bases[NumGoodBases++] = Bases[idx];
1165      if (const RecordType *Record = NewBaseType->getAs<RecordType>())
1166        if (const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl()))
1167          if (RD->hasAttr<WeakAttr>())
1168            Class->addAttr(::new (Context) WeakAttr(SourceRange(), Context));
1169    }
1170  }
1171
1172  // Attach the remaining base class specifiers to the derived class.
1173  Class->setBases(Bases, NumGoodBases);
1174
1175  // Delete the remaining (good) base class specifiers, since their
1176  // data has been copied into the CXXRecordDecl.
1177  for (unsigned idx = 0; idx < NumGoodBases; ++idx)
1178    Context.Deallocate(Bases[idx]);
1179
1180  return Invalid;
1181}
1182
1183/// ActOnBaseSpecifiers - Attach the given base specifiers to the
1184/// class, after checking whether there are any duplicate base
1185/// classes.
1186void Sema::ActOnBaseSpecifiers(Decl *ClassDecl, CXXBaseSpecifier **Bases,
1187                               unsigned NumBases) {
1188  if (!ClassDecl || !Bases || !NumBases)
1189    return;
1190
1191  AdjustDeclIfTemplate(ClassDecl);
1192  AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl),
1193                       (CXXBaseSpecifier**)(Bases), NumBases);
1194}
1195
1196static CXXRecordDecl *GetClassForType(QualType T) {
1197  if (const RecordType *RT = T->getAs<RecordType>())
1198    return cast<CXXRecordDecl>(RT->getDecl());
1199  else if (const InjectedClassNameType *ICT = T->getAs<InjectedClassNameType>())
1200    return ICT->getDecl();
1201  else
1202    return 0;
1203}
1204
1205/// \brief Determine whether the type \p Derived is a C++ class that is
1206/// derived from the type \p Base.
1207bool Sema::IsDerivedFrom(QualType Derived, QualType Base) {
1208  if (!getLangOpts().CPlusPlus)
1209    return false;
1210
1211  CXXRecordDecl *DerivedRD = GetClassForType(Derived);
1212  if (!DerivedRD)
1213    return false;
1214
1215  CXXRecordDecl *BaseRD = GetClassForType(Base);
1216  if (!BaseRD)
1217    return false;
1218
1219  // FIXME: instantiate DerivedRD if necessary.  We need a PoI for this.
1220  return DerivedRD->hasDefinition() && DerivedRD->isDerivedFrom(BaseRD);
1221}
1222
1223/// \brief Determine whether the type \p Derived is a C++ class that is
1224/// derived from the type \p Base.
1225bool Sema::IsDerivedFrom(QualType Derived, QualType Base, CXXBasePaths &Paths) {
1226  if (!getLangOpts().CPlusPlus)
1227    return false;
1228
1229  CXXRecordDecl *DerivedRD = GetClassForType(Derived);
1230  if (!DerivedRD)
1231    return false;
1232
1233  CXXRecordDecl *BaseRD = GetClassForType(Base);
1234  if (!BaseRD)
1235    return false;
1236
1237  return DerivedRD->isDerivedFrom(BaseRD, Paths);
1238}
1239
1240void Sema::BuildBasePathArray(const CXXBasePaths &Paths,
1241                              CXXCastPath &BasePathArray) {
1242  assert(BasePathArray.empty() && "Base path array must be empty!");
1243  assert(Paths.isRecordingPaths() && "Must record paths!");
1244
1245  const CXXBasePath &Path = Paths.front();
1246
1247  // We first go backward and check if we have a virtual base.
1248  // FIXME: It would be better if CXXBasePath had the base specifier for
1249  // the nearest virtual base.
1250  unsigned Start = 0;
1251  for (unsigned I = Path.size(); I != 0; --I) {
1252    if (Path[I - 1].Base->isVirtual()) {
1253      Start = I - 1;
1254      break;
1255    }
1256  }
1257
1258  // Now add all bases.
1259  for (unsigned I = Start, E = Path.size(); I != E; ++I)
1260    BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
1261}
1262
1263/// \brief Determine whether the given base path includes a virtual
1264/// base class.
1265bool Sema::BasePathInvolvesVirtualBase(const CXXCastPath &BasePath) {
1266  for (CXXCastPath::const_iterator B = BasePath.begin(),
1267                                BEnd = BasePath.end();
1268       B != BEnd; ++B)
1269    if ((*B)->isVirtual())
1270      return true;
1271
1272  return false;
1273}
1274
1275/// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
1276/// conversion (where Derived and Base are class types) is
1277/// well-formed, meaning that the conversion is unambiguous (and
1278/// that all of the base classes are accessible). Returns true
1279/// and emits a diagnostic if the code is ill-formed, returns false
1280/// otherwise. Loc is the location where this routine should point to
1281/// if there is an error, and Range is the source range to highlight
1282/// if there is an error.
1283bool
1284Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
1285                                   unsigned InaccessibleBaseID,
1286                                   unsigned AmbigiousBaseConvID,
1287                                   SourceLocation Loc, SourceRange Range,
1288                                   DeclarationName Name,
1289                                   CXXCastPath *BasePath) {
1290  // First, determine whether the path from Derived to Base is
1291  // ambiguous. This is slightly more expensive than checking whether
1292  // the Derived to Base conversion exists, because here we need to
1293  // explore multiple paths to determine if there is an ambiguity.
1294  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1295                     /*DetectVirtual=*/false);
1296  bool DerivationOkay = IsDerivedFrom(Derived, Base, Paths);
1297  assert(DerivationOkay &&
1298         "Can only be used with a derived-to-base conversion");
1299  (void)DerivationOkay;
1300
1301  if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType())) {
1302    if (InaccessibleBaseID) {
1303      // Check that the base class can be accessed.
1304      switch (CheckBaseClassAccess(Loc, Base, Derived, Paths.front(),
1305                                   InaccessibleBaseID)) {
1306        case AR_inaccessible:
1307          return true;
1308        case AR_accessible:
1309        case AR_dependent:
1310        case AR_delayed:
1311          break;
1312      }
1313    }
1314
1315    // Build a base path if necessary.
1316    if (BasePath)
1317      BuildBasePathArray(Paths, *BasePath);
1318    return false;
1319  }
1320
1321  // We know that the derived-to-base conversion is ambiguous, and
1322  // we're going to produce a diagnostic. Perform the derived-to-base
1323  // search just one more time to compute all of the possible paths so
1324  // that we can print them out. This is more expensive than any of
1325  // the previous derived-to-base checks we've done, but at this point
1326  // performance isn't as much of an issue.
1327  Paths.clear();
1328  Paths.setRecordingPaths(true);
1329  bool StillOkay = IsDerivedFrom(Derived, Base, Paths);
1330  assert(StillOkay && "Can only be used with a derived-to-base conversion");
1331  (void)StillOkay;
1332
1333  // Build up a textual representation of the ambiguous paths, e.g.,
1334  // D -> B -> A, that will be used to illustrate the ambiguous
1335  // conversions in the diagnostic. We only print one of the paths
1336  // to each base class subobject.
1337  std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
1338
1339  Diag(Loc, AmbigiousBaseConvID)
1340  << Derived << Base << PathDisplayStr << Range << Name;
1341  return true;
1342}
1343
1344bool
1345Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
1346                                   SourceLocation Loc, SourceRange Range,
1347                                   CXXCastPath *BasePath,
1348                                   bool IgnoreAccess) {
1349  return CheckDerivedToBaseConversion(Derived, Base,
1350                                      IgnoreAccess ? 0
1351                                       : diag::err_upcast_to_inaccessible_base,
1352                                      diag::err_ambiguous_derived_to_base_conv,
1353                                      Loc, Range, DeclarationName(),
1354                                      BasePath);
1355}
1356
1357
1358/// @brief Builds a string representing ambiguous paths from a
1359/// specific derived class to different subobjects of the same base
1360/// class.
1361///
1362/// This function builds a string that can be used in error messages
1363/// to show the different paths that one can take through the
1364/// inheritance hierarchy to go from the derived class to different
1365/// subobjects of a base class. The result looks something like this:
1366/// @code
1367/// struct D -> struct B -> struct A
1368/// struct D -> struct C -> struct A
1369/// @endcode
1370std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
1371  std::string PathDisplayStr;
1372  std::set<unsigned> DisplayedPaths;
1373  for (CXXBasePaths::paths_iterator Path = Paths.begin();
1374       Path != Paths.end(); ++Path) {
1375    if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
1376      // We haven't displayed a path to this particular base
1377      // class subobject yet.
1378      PathDisplayStr += "\n    ";
1379      PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
1380      for (CXXBasePath::const_iterator Element = Path->begin();
1381           Element != Path->end(); ++Element)
1382        PathDisplayStr += " -> " + Element->Base->getType().getAsString();
1383    }
1384  }
1385
1386  return PathDisplayStr;
1387}
1388
1389//===----------------------------------------------------------------------===//
1390// C++ class member Handling
1391//===----------------------------------------------------------------------===//
1392
1393/// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
1394bool Sema::ActOnAccessSpecifier(AccessSpecifier Access,
1395                                SourceLocation ASLoc,
1396                                SourceLocation ColonLoc,
1397                                AttributeList *Attrs) {
1398  assert(Access != AS_none && "Invalid kind for syntactic access specifier!");
1399  AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
1400                                                  ASLoc, ColonLoc);
1401  CurContext->addHiddenDecl(ASDecl);
1402  return ProcessAccessDeclAttributeList(ASDecl, Attrs);
1403}
1404
1405/// CheckOverrideControl - Check C++0x override control semantics.
1406void Sema::CheckOverrideControl(const Decl *D) {
1407  const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
1408  if (!MD || !MD->isVirtual())
1409    return;
1410
1411  if (MD->isDependentContext())
1412    return;
1413
1414  // C++0x [class.virtual]p3:
1415  //   If a virtual function is marked with the virt-specifier override and does
1416  //   not override a member function of a base class,
1417  //   the program is ill-formed.
1418  bool HasOverriddenMethods =
1419    MD->begin_overridden_methods() != MD->end_overridden_methods();
1420  if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods) {
1421    Diag(MD->getLocation(),
1422                 diag::err_function_marked_override_not_overriding)
1423      << MD->getDeclName();
1424    return;
1425  }
1426}
1427
1428/// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
1429/// function overrides a virtual member function marked 'final', according to
1430/// C++0x [class.virtual]p3.
1431bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
1432                                                  const CXXMethodDecl *Old) {
1433  if (!Old->hasAttr<FinalAttr>())
1434    return false;
1435
1436  Diag(New->getLocation(), diag::err_final_function_overridden)
1437    << New->getDeclName();
1438  Diag(Old->getLocation(), diag::note_overridden_virtual_function);
1439  return true;
1440}
1441
1442static bool InitializationHasSideEffects(const FieldDecl &FD) {
1443  if (!FD.getType().isNull()) {
1444    if (const CXXRecordDecl *RD = FD.getType()->getAsCXXRecordDecl()) {
1445      return !RD->isCompleteDefinition() ||
1446             !RD->hasTrivialDefaultConstructor() ||
1447             !RD->hasTrivialDestructor();
1448    }
1449  }
1450  return false;
1451}
1452
1453/// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
1454/// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
1455/// bitfield width if there is one, 'InitExpr' specifies the initializer if
1456/// one has been parsed, and 'InitStyle' is set if an in-class initializer is
1457/// present (but parsing it has been deferred).
1458Decl *
1459Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
1460                               MultiTemplateParamsArg TemplateParameterLists,
1461                               Expr *BW, const VirtSpecifiers &VS,
1462                               InClassInitStyle InitStyle) {
1463  const DeclSpec &DS = D.getDeclSpec();
1464  DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
1465  DeclarationName Name = NameInfo.getName();
1466  SourceLocation Loc = NameInfo.getLoc();
1467
1468  // For anonymous bitfields, the location should point to the type.
1469  if (Loc.isInvalid())
1470    Loc = D.getLocStart();
1471
1472  Expr *BitWidth = static_cast<Expr*>(BW);
1473
1474  assert(isa<CXXRecordDecl>(CurContext));
1475  assert(!DS.isFriendSpecified());
1476
1477  bool isFunc = D.isDeclarationOfFunction();
1478
1479  // C++ 9.2p6: A member shall not be declared to have automatic storage
1480  // duration (auto, register) or with the extern storage-class-specifier.
1481  // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
1482  // data members and cannot be applied to names declared const or static,
1483  // and cannot be applied to reference members.
1484  switch (DS.getStorageClassSpec()) {
1485    case DeclSpec::SCS_unspecified:
1486    case DeclSpec::SCS_typedef:
1487    case DeclSpec::SCS_static:
1488      // FALL THROUGH.
1489      break;
1490    case DeclSpec::SCS_mutable:
1491      if (isFunc) {
1492        if (DS.getStorageClassSpecLoc().isValid())
1493          Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
1494        else
1495          Diag(DS.getThreadSpecLoc(), diag::err_mutable_function);
1496
1497        // FIXME: It would be nicer if the keyword was ignored only for this
1498        // declarator. Otherwise we could get follow-up errors.
1499        D.getMutableDeclSpec().ClearStorageClassSpecs();
1500      }
1501      break;
1502    default:
1503      if (DS.getStorageClassSpecLoc().isValid())
1504        Diag(DS.getStorageClassSpecLoc(),
1505             diag::err_storageclass_invalid_for_member);
1506      else
1507        Diag(DS.getThreadSpecLoc(), diag::err_storageclass_invalid_for_member);
1508      D.getMutableDeclSpec().ClearStorageClassSpecs();
1509  }
1510
1511  bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
1512                       DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
1513                      !isFunc);
1514
1515  Decl *Member;
1516  if (isInstField) {
1517    CXXScopeSpec &SS = D.getCXXScopeSpec();
1518
1519    // Data members must have identifiers for names.
1520    if (!Name.isIdentifier()) {
1521      Diag(Loc, diag::err_bad_variable_name)
1522        << Name;
1523      return 0;
1524    }
1525
1526    IdentifierInfo *II = Name.getAsIdentifierInfo();
1527
1528    // Member field could not be with "template" keyword.
1529    // So TemplateParameterLists should be empty in this case.
1530    if (TemplateParameterLists.size()) {
1531      TemplateParameterList* TemplateParams = TemplateParameterLists.get()[0];
1532      if (TemplateParams->size()) {
1533        // There is no such thing as a member field template.
1534        Diag(D.getIdentifierLoc(), diag::err_template_member)
1535            << II
1536            << SourceRange(TemplateParams->getTemplateLoc(),
1537                TemplateParams->getRAngleLoc());
1538      } else {
1539        // There is an extraneous 'template<>' for this member.
1540        Diag(TemplateParams->getTemplateLoc(),
1541            diag::err_template_member_noparams)
1542            << II
1543            << SourceRange(TemplateParams->getTemplateLoc(),
1544                TemplateParams->getRAngleLoc());
1545      }
1546      return 0;
1547    }
1548
1549    if (SS.isSet() && !SS.isInvalid()) {
1550      // The user provided a superfluous scope specifier inside a class
1551      // definition:
1552      //
1553      // class X {
1554      //   int X::member;
1555      // };
1556      if (DeclContext *DC = computeDeclContext(SS, false))
1557        diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc());
1558      else
1559        Diag(D.getIdentifierLoc(), diag::err_member_qualification)
1560          << Name << SS.getRange();
1561
1562      SS.clear();
1563    }
1564
1565    Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D, BitWidth,
1566                         InitStyle, AS);
1567    assert(Member && "HandleField never returns null");
1568  } else {
1569    assert(InitStyle == ICIS_NoInit);
1570
1571    Member = HandleDeclarator(S, D, move(TemplateParameterLists));
1572    if (!Member) {
1573      return 0;
1574    }
1575
1576    // Non-instance-fields can't have a bitfield.
1577    if (BitWidth) {
1578      if (Member->isInvalidDecl()) {
1579        // don't emit another diagnostic.
1580      } else if (isa<VarDecl>(Member)) {
1581        // C++ 9.6p3: A bit-field shall not be a static member.
1582        // "static member 'A' cannot be a bit-field"
1583        Diag(Loc, diag::err_static_not_bitfield)
1584          << Name << BitWidth->getSourceRange();
1585      } else if (isa<TypedefDecl>(Member)) {
1586        // "typedef member 'x' cannot be a bit-field"
1587        Diag(Loc, diag::err_typedef_not_bitfield)
1588          << Name << BitWidth->getSourceRange();
1589      } else {
1590        // A function typedef ("typedef int f(); f a;").
1591        // C++ 9.6p3: A bit-field shall have integral or enumeration type.
1592        Diag(Loc, diag::err_not_integral_type_bitfield)
1593          << Name << cast<ValueDecl>(Member)->getType()
1594          << BitWidth->getSourceRange();
1595      }
1596
1597      BitWidth = 0;
1598      Member->setInvalidDecl();
1599    }
1600
1601    Member->setAccess(AS);
1602
1603    // If we have declared a member function template, set the access of the
1604    // templated declaration as well.
1605    if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
1606      FunTmpl->getTemplatedDecl()->setAccess(AS);
1607  }
1608
1609  if (VS.isOverrideSpecified()) {
1610    CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
1611    if (!MD || !MD->isVirtual()) {
1612      Diag(Member->getLocStart(),
1613           diag::override_keyword_only_allowed_on_virtual_member_functions)
1614        << "override" << FixItHint::CreateRemoval(VS.getOverrideLoc());
1615    } else
1616      MD->addAttr(new (Context) OverrideAttr(VS.getOverrideLoc(), Context));
1617  }
1618  if (VS.isFinalSpecified()) {
1619    CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
1620    if (!MD || !MD->isVirtual()) {
1621      Diag(Member->getLocStart(),
1622           diag::override_keyword_only_allowed_on_virtual_member_functions)
1623      << "final" << FixItHint::CreateRemoval(VS.getFinalLoc());
1624    } else
1625      MD->addAttr(new (Context) FinalAttr(VS.getFinalLoc(), Context));
1626  }
1627
1628  if (VS.getLastLocation().isValid()) {
1629    // Update the end location of a method that has a virt-specifiers.
1630    if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
1631      MD->setRangeEnd(VS.getLastLocation());
1632  }
1633
1634  CheckOverrideControl(Member);
1635
1636  assert((Name || isInstField) && "No identifier for non-field ?");
1637
1638  if (isInstField) {
1639    FieldDecl *FD = cast<FieldDecl>(Member);
1640    FieldCollector->Add(FD);
1641
1642    if (Diags.getDiagnosticLevel(diag::warn_unused_private_field,
1643                                 FD->getLocation())
1644          != DiagnosticsEngine::Ignored) {
1645      // Remember all explicit private FieldDecls that have a name, no side
1646      // effects and are not part of a dependent type declaration.
1647      if (!FD->isImplicit() && FD->getDeclName() &&
1648          FD->getAccess() == AS_private &&
1649          !FD->getParent()->getTypeForDecl()->isDependentType() &&
1650          !InitializationHasSideEffects(*FD))
1651        UnusedPrivateFields.insert(FD);
1652    }
1653  }
1654
1655  return Member;
1656}
1657
1658/// ActOnCXXInClassMemberInitializer - This is invoked after parsing an
1659/// in-class initializer for a non-static C++ class member, and after
1660/// instantiating an in-class initializer in a class template. Such actions
1661/// are deferred until the class is complete.
1662void
1663Sema::ActOnCXXInClassMemberInitializer(Decl *D, SourceLocation InitLoc,
1664                                       Expr *InitExpr) {
1665  FieldDecl *FD = cast<FieldDecl>(D);
1666  assert(FD->getInClassInitStyle() != ICIS_NoInit &&
1667         "must set init style when field is created");
1668
1669  if (!InitExpr) {
1670    FD->setInvalidDecl();
1671    FD->removeInClassInitializer();
1672    return;
1673  }
1674
1675  if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
1676    FD->setInvalidDecl();
1677    FD->removeInClassInitializer();
1678    return;
1679  }
1680
1681  ExprResult Init = InitExpr;
1682  if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
1683    if (isa<InitListExpr>(InitExpr) && isStdInitializerList(FD->getType(), 0)) {
1684      Diag(FD->getLocation(), diag::warn_dangling_std_initializer_list)
1685        << /*at end of ctor*/1 << InitExpr->getSourceRange();
1686    }
1687    Expr **Inits = &InitExpr;
1688    unsigned NumInits = 1;
1689    InitializedEntity Entity = InitializedEntity::InitializeMember(FD);
1690    InitializationKind Kind = FD->getInClassInitStyle() == ICIS_ListInit
1691        ? InitializationKind::CreateDirectList(InitExpr->getLocStart())
1692        : InitializationKind::CreateCopy(InitExpr->getLocStart(), InitLoc);
1693    InitializationSequence Seq(*this, Entity, Kind, Inits, NumInits);
1694    Init = Seq.Perform(*this, Entity, Kind, MultiExprArg(Inits, NumInits));
1695    if (Init.isInvalid()) {
1696      FD->setInvalidDecl();
1697      return;
1698    }
1699
1700    CheckImplicitConversions(Init.get(), InitLoc);
1701  }
1702
1703  // C++0x [class.base.init]p7:
1704  //   The initialization of each base and member constitutes a
1705  //   full-expression.
1706  Init = MaybeCreateExprWithCleanups(Init);
1707  if (Init.isInvalid()) {
1708    FD->setInvalidDecl();
1709    return;
1710  }
1711
1712  InitExpr = Init.release();
1713
1714  FD->setInClassInitializer(InitExpr);
1715}
1716
1717/// \brief Find the direct and/or virtual base specifiers that
1718/// correspond to the given base type, for use in base initialization
1719/// within a constructor.
1720static bool FindBaseInitializer(Sema &SemaRef,
1721                                CXXRecordDecl *ClassDecl,
1722                                QualType BaseType,
1723                                const CXXBaseSpecifier *&DirectBaseSpec,
1724                                const CXXBaseSpecifier *&VirtualBaseSpec) {
1725  // First, check for a direct base class.
1726  DirectBaseSpec = 0;
1727  for (CXXRecordDecl::base_class_const_iterator Base
1728         = ClassDecl->bases_begin();
1729       Base != ClassDecl->bases_end(); ++Base) {
1730    if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base->getType())) {
1731      // We found a direct base of this type. That's what we're
1732      // initializing.
1733      DirectBaseSpec = &*Base;
1734      break;
1735    }
1736  }
1737
1738  // Check for a virtual base class.
1739  // FIXME: We might be able to short-circuit this if we know in advance that
1740  // there are no virtual bases.
1741  VirtualBaseSpec = 0;
1742  if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
1743    // We haven't found a base yet; search the class hierarchy for a
1744    // virtual base class.
1745    CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1746                       /*DetectVirtual=*/false);
1747    if (SemaRef.IsDerivedFrom(SemaRef.Context.getTypeDeclType(ClassDecl),
1748                              BaseType, Paths)) {
1749      for (CXXBasePaths::paths_iterator Path = Paths.begin();
1750           Path != Paths.end(); ++Path) {
1751        if (Path->back().Base->isVirtual()) {
1752          VirtualBaseSpec = Path->back().Base;
1753          break;
1754        }
1755      }
1756    }
1757  }
1758
1759  return DirectBaseSpec || VirtualBaseSpec;
1760}
1761
1762/// \brief Handle a C++ member initializer using braced-init-list syntax.
1763MemInitResult
1764Sema::ActOnMemInitializer(Decl *ConstructorD,
1765                          Scope *S,
1766                          CXXScopeSpec &SS,
1767                          IdentifierInfo *MemberOrBase,
1768                          ParsedType TemplateTypeTy,
1769                          const DeclSpec &DS,
1770                          SourceLocation IdLoc,
1771                          Expr *InitList,
1772                          SourceLocation EllipsisLoc) {
1773  return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
1774                             DS, IdLoc, InitList,
1775                             EllipsisLoc);
1776}
1777
1778/// \brief Handle a C++ member initializer using parentheses syntax.
1779MemInitResult
1780Sema::ActOnMemInitializer(Decl *ConstructorD,
1781                          Scope *S,
1782                          CXXScopeSpec &SS,
1783                          IdentifierInfo *MemberOrBase,
1784                          ParsedType TemplateTypeTy,
1785                          const DeclSpec &DS,
1786                          SourceLocation IdLoc,
1787                          SourceLocation LParenLoc,
1788                          Expr **Args, unsigned NumArgs,
1789                          SourceLocation RParenLoc,
1790                          SourceLocation EllipsisLoc) {
1791  Expr *List = new (Context) ParenListExpr(Context, LParenLoc, Args, NumArgs,
1792                                           RParenLoc);
1793  return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
1794                             DS, IdLoc, List, EllipsisLoc);
1795}
1796
1797namespace {
1798
1799// Callback to only accept typo corrections that can be a valid C++ member
1800// intializer: either a non-static field member or a base class.
1801class MemInitializerValidatorCCC : public CorrectionCandidateCallback {
1802 public:
1803  explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
1804      : ClassDecl(ClassDecl) {}
1805
1806  virtual bool ValidateCandidate(const TypoCorrection &candidate) {
1807    if (NamedDecl *ND = candidate.getCorrectionDecl()) {
1808      if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
1809        return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
1810      else
1811        return isa<TypeDecl>(ND);
1812    }
1813    return false;
1814  }
1815
1816 private:
1817  CXXRecordDecl *ClassDecl;
1818};
1819
1820}
1821
1822/// \brief Handle a C++ member initializer.
1823MemInitResult
1824Sema::BuildMemInitializer(Decl *ConstructorD,
1825                          Scope *S,
1826                          CXXScopeSpec &SS,
1827                          IdentifierInfo *MemberOrBase,
1828                          ParsedType TemplateTypeTy,
1829                          const DeclSpec &DS,
1830                          SourceLocation IdLoc,
1831                          Expr *Init,
1832                          SourceLocation EllipsisLoc) {
1833  if (!ConstructorD)
1834    return true;
1835
1836  AdjustDeclIfTemplate(ConstructorD);
1837
1838  CXXConstructorDecl *Constructor
1839    = dyn_cast<CXXConstructorDecl>(ConstructorD);
1840  if (!Constructor) {
1841    // The user wrote a constructor initializer on a function that is
1842    // not a C++ constructor. Ignore the error for now, because we may
1843    // have more member initializers coming; we'll diagnose it just
1844    // once in ActOnMemInitializers.
1845    return true;
1846  }
1847
1848  CXXRecordDecl *ClassDecl = Constructor->getParent();
1849
1850  // C++ [class.base.init]p2:
1851  //   Names in a mem-initializer-id are looked up in the scope of the
1852  //   constructor's class and, if not found in that scope, are looked
1853  //   up in the scope containing the constructor's definition.
1854  //   [Note: if the constructor's class contains a member with the
1855  //   same name as a direct or virtual base class of the class, a
1856  //   mem-initializer-id naming the member or base class and composed
1857  //   of a single identifier refers to the class member. A
1858  //   mem-initializer-id for the hidden base class may be specified
1859  //   using a qualified name. ]
1860  if (!SS.getScopeRep() && !TemplateTypeTy) {
1861    // Look for a member, first.
1862    DeclContext::lookup_result Result
1863      = ClassDecl->lookup(MemberOrBase);
1864    if (Result.first != Result.second) {
1865      ValueDecl *Member;
1866      if ((Member = dyn_cast<FieldDecl>(*Result.first)) ||
1867          (Member = dyn_cast<IndirectFieldDecl>(*Result.first))) {
1868        if (EllipsisLoc.isValid())
1869          Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
1870            << MemberOrBase
1871            << SourceRange(IdLoc, Init->getSourceRange().getEnd());
1872
1873        return BuildMemberInitializer(Member, Init, IdLoc);
1874      }
1875    }
1876  }
1877  // It didn't name a member, so see if it names a class.
1878  QualType BaseType;
1879  TypeSourceInfo *TInfo = 0;
1880
1881  if (TemplateTypeTy) {
1882    BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
1883  } else if (DS.getTypeSpecType() == TST_decltype) {
1884    BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
1885  } else {
1886    LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
1887    LookupParsedName(R, S, &SS);
1888
1889    TypeDecl *TyD = R.getAsSingle<TypeDecl>();
1890    if (!TyD) {
1891      if (R.isAmbiguous()) return true;
1892
1893      // We don't want access-control diagnostics here.
1894      R.suppressDiagnostics();
1895
1896      if (SS.isSet() && isDependentScopeSpecifier(SS)) {
1897        bool NotUnknownSpecialization = false;
1898        DeclContext *DC = computeDeclContext(SS, false);
1899        if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
1900          NotUnknownSpecialization = !Record->hasAnyDependentBases();
1901
1902        if (!NotUnknownSpecialization) {
1903          // When the scope specifier can refer to a member of an unknown
1904          // specialization, we take it as a type name.
1905          BaseType = CheckTypenameType(ETK_None, SourceLocation(),
1906                                       SS.getWithLocInContext(Context),
1907                                       *MemberOrBase, IdLoc);
1908          if (BaseType.isNull())
1909            return true;
1910
1911          R.clear();
1912          R.setLookupName(MemberOrBase);
1913        }
1914      }
1915
1916      // If no results were found, try to correct typos.
1917      TypoCorrection Corr;
1918      MemInitializerValidatorCCC Validator(ClassDecl);
1919      if (R.empty() && BaseType.isNull() &&
1920          (Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
1921                              Validator, ClassDecl))) {
1922        std::string CorrectedStr(Corr.getAsString(getLangOpts()));
1923        std::string CorrectedQuotedStr(Corr.getQuoted(getLangOpts()));
1924        if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
1925          // We have found a non-static data member with a similar
1926          // name to what was typed; complain and initialize that
1927          // member.
1928          Diag(R.getNameLoc(), diag::err_mem_init_not_member_or_class_suggest)
1929            << MemberOrBase << true << CorrectedQuotedStr
1930            << FixItHint::CreateReplacement(R.getNameLoc(), CorrectedStr);
1931          Diag(Member->getLocation(), diag::note_previous_decl)
1932            << CorrectedQuotedStr;
1933
1934          return BuildMemberInitializer(Member, Init, IdLoc);
1935        } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
1936          const CXXBaseSpecifier *DirectBaseSpec;
1937          const CXXBaseSpecifier *VirtualBaseSpec;
1938          if (FindBaseInitializer(*this, ClassDecl,
1939                                  Context.getTypeDeclType(Type),
1940                                  DirectBaseSpec, VirtualBaseSpec)) {
1941            // We have found a direct or virtual base class with a
1942            // similar name to what was typed; complain and initialize
1943            // that base class.
1944            Diag(R.getNameLoc(), diag::err_mem_init_not_member_or_class_suggest)
1945              << MemberOrBase << false << CorrectedQuotedStr
1946              << FixItHint::CreateReplacement(R.getNameLoc(), CorrectedStr);
1947
1948            const CXXBaseSpecifier *BaseSpec = DirectBaseSpec? DirectBaseSpec
1949                                                             : VirtualBaseSpec;
1950            Diag(BaseSpec->getLocStart(),
1951                 diag::note_base_class_specified_here)
1952              << BaseSpec->getType()
1953              << BaseSpec->getSourceRange();
1954
1955            TyD = Type;
1956          }
1957        }
1958      }
1959
1960      if (!TyD && BaseType.isNull()) {
1961        Diag(IdLoc, diag::err_mem_init_not_member_or_class)
1962          << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
1963        return true;
1964      }
1965    }
1966
1967    if (BaseType.isNull()) {
1968      BaseType = Context.getTypeDeclType(TyD);
1969      if (SS.isSet()) {
1970        NestedNameSpecifier *Qualifier =
1971          static_cast<NestedNameSpecifier*>(SS.getScopeRep());
1972
1973        // FIXME: preserve source range information
1974        BaseType = Context.getElaboratedType(ETK_None, Qualifier, BaseType);
1975      }
1976    }
1977  }
1978
1979  if (!TInfo)
1980    TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
1981
1982  return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
1983}
1984
1985/// Checks a member initializer expression for cases where reference (or
1986/// pointer) members are bound to by-value parameters (or their addresses).
1987static void CheckForDanglingReferenceOrPointer(Sema &S, ValueDecl *Member,
1988                                               Expr *Init,
1989                                               SourceLocation IdLoc) {
1990  QualType MemberTy = Member->getType();
1991
1992  // We only handle pointers and references currently.
1993  // FIXME: Would this be relevant for ObjC object pointers? Or block pointers?
1994  if (!MemberTy->isReferenceType() && !MemberTy->isPointerType())
1995    return;
1996
1997  const bool IsPointer = MemberTy->isPointerType();
1998  if (IsPointer) {
1999    if (const UnaryOperator *Op
2000          = dyn_cast<UnaryOperator>(Init->IgnoreParenImpCasts())) {
2001      // The only case we're worried about with pointers requires taking the
2002      // address.
2003      if (Op->getOpcode() != UO_AddrOf)
2004        return;
2005
2006      Init = Op->getSubExpr();
2007    } else {
2008      // We only handle address-of expression initializers for pointers.
2009      return;
2010    }
2011  }
2012
2013  if (isa<MaterializeTemporaryExpr>(Init->IgnoreParens())) {
2014    // Taking the address of a temporary will be diagnosed as a hard error.
2015    if (IsPointer)
2016      return;
2017
2018    S.Diag(Init->getExprLoc(), diag::warn_bind_ref_member_to_temporary)
2019      << Member << Init->getSourceRange();
2020  } else if (const DeclRefExpr *DRE
2021               = dyn_cast<DeclRefExpr>(Init->IgnoreParens())) {
2022    // We only warn when referring to a non-reference parameter declaration.
2023    const ParmVarDecl *Parameter = dyn_cast<ParmVarDecl>(DRE->getDecl());
2024    if (!Parameter || Parameter->getType()->isReferenceType())
2025      return;
2026
2027    S.Diag(Init->getExprLoc(),
2028           IsPointer ? diag::warn_init_ptr_member_to_parameter_addr
2029                     : diag::warn_bind_ref_member_to_parameter)
2030      << Member << Parameter << Init->getSourceRange();
2031  } else {
2032    // Other initializers are fine.
2033    return;
2034  }
2035
2036  S.Diag(Member->getLocation(), diag::note_ref_or_ptr_member_declared_here)
2037    << (unsigned)IsPointer;
2038}
2039
2040/// Checks an initializer expression for use of uninitialized fields, such as
2041/// containing the field that is being initialized. Returns true if there is an
2042/// uninitialized field was used an updates the SourceLocation parameter; false
2043/// otherwise.
2044static bool InitExprContainsUninitializedFields(const Stmt *S,
2045                                                const ValueDecl *LhsField,
2046                                                SourceLocation *L) {
2047  assert(isa<FieldDecl>(LhsField) || isa<IndirectFieldDecl>(LhsField));
2048
2049  if (isa<CallExpr>(S)) {
2050    // Do not descend into function calls or constructors, as the use
2051    // of an uninitialized field may be valid. One would have to inspect
2052    // the contents of the function/ctor to determine if it is safe or not.
2053    // i.e. Pass-by-value is never safe, but pass-by-reference and pointers
2054    // may be safe, depending on what the function/ctor does.
2055    return false;
2056  }
2057  if (const MemberExpr *ME = dyn_cast<MemberExpr>(S)) {
2058    const NamedDecl *RhsField = ME->getMemberDecl();
2059
2060    if (const VarDecl *VD = dyn_cast<VarDecl>(RhsField)) {
2061      // The member expression points to a static data member.
2062      assert(VD->isStaticDataMember() &&
2063             "Member points to non-static data member!");
2064      (void)VD;
2065      return false;
2066    }
2067
2068    if (isa<EnumConstantDecl>(RhsField)) {
2069      // The member expression points to an enum.
2070      return false;
2071    }
2072
2073    if (RhsField == LhsField) {
2074      // Initializing a field with itself. Throw a warning.
2075      // But wait; there are exceptions!
2076      // Exception #1:  The field may not belong to this record.
2077      // e.g. Foo(const Foo& rhs) : A(rhs.A) {}
2078      const Expr *base = ME->getBase();
2079      if (base != NULL && !isa<CXXThisExpr>(base->IgnoreParenCasts())) {
2080        // Even though the field matches, it does not belong to this record.
2081        return false;
2082      }
2083      // None of the exceptions triggered; return true to indicate an
2084      // uninitialized field was used.
2085      *L = ME->getMemberLoc();
2086      return true;
2087    }
2088  } else if (isa<UnaryExprOrTypeTraitExpr>(S)) {
2089    // sizeof/alignof doesn't reference contents, do not warn.
2090    return false;
2091  } else if (const UnaryOperator *UOE = dyn_cast<UnaryOperator>(S)) {
2092    // address-of doesn't reference contents (the pointer may be dereferenced
2093    // in the same expression but it would be rare; and weird).
2094    if (UOE->getOpcode() == UO_AddrOf)
2095      return false;
2096  }
2097  for (Stmt::const_child_range it = S->children(); it; ++it) {
2098    if (!*it) {
2099      // An expression such as 'member(arg ?: "")' may trigger this.
2100      continue;
2101    }
2102    if (InitExprContainsUninitializedFields(*it, LhsField, L))
2103      return true;
2104  }
2105  return false;
2106}
2107
2108MemInitResult
2109Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
2110                             SourceLocation IdLoc) {
2111  FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
2112  IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
2113  assert((DirectMember || IndirectMember) &&
2114         "Member must be a FieldDecl or IndirectFieldDecl");
2115
2116  if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
2117    return true;
2118
2119  if (Member->isInvalidDecl())
2120    return true;
2121
2122  // Diagnose value-uses of fields to initialize themselves, e.g.
2123  //   foo(foo)
2124  // where foo is not also a parameter to the constructor.
2125  // TODO: implement -Wuninitialized and fold this into that framework.
2126  Expr **Args;
2127  unsigned NumArgs;
2128  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
2129    Args = ParenList->getExprs();
2130    NumArgs = ParenList->getNumExprs();
2131  } else {
2132    InitListExpr *InitList = cast<InitListExpr>(Init);
2133    Args = InitList->getInits();
2134    NumArgs = InitList->getNumInits();
2135  }
2136
2137  // Mark FieldDecl as being used if it is a non-primitive type and the
2138  // initializer does not call the default constructor (which is trivial
2139  // for all entries in UnusedPrivateFields).
2140  // FIXME: Make this smarter once more side effect-free types can be
2141  // determined.
2142  if (NumArgs > 0) {
2143    if (Member->getType()->isRecordType()) {
2144      UnusedPrivateFields.remove(Member);
2145    } else {
2146      for (unsigned i = 0; i < NumArgs; ++i) {
2147        if (Args[i]->HasSideEffects(Context)) {
2148          UnusedPrivateFields.remove(Member);
2149          break;
2150        }
2151      }
2152    }
2153  }
2154
2155  for (unsigned i = 0; i < NumArgs; ++i) {
2156    SourceLocation L;
2157    if (InitExprContainsUninitializedFields(Args[i], Member, &L)) {
2158      // FIXME: Return true in the case when other fields are used before being
2159      // uninitialized. For example, let this field be the i'th field. When
2160      // initializing the i'th field, throw a warning if any of the >= i'th
2161      // fields are used, as they are not yet initialized.
2162      // Right now we are only handling the case where the i'th field uses
2163      // itself in its initializer.
2164      Diag(L, diag::warn_field_is_uninit);
2165    }
2166  }
2167
2168  SourceRange InitRange = Init->getSourceRange();
2169
2170  if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
2171    // Can't check initialization for a member of dependent type or when
2172    // any of the arguments are type-dependent expressions.
2173    DiscardCleanupsInEvaluationContext();
2174  } else {
2175    bool InitList = false;
2176    if (isa<InitListExpr>(Init)) {
2177      InitList = true;
2178      Args = &Init;
2179      NumArgs = 1;
2180
2181      if (isStdInitializerList(Member->getType(), 0)) {
2182        Diag(IdLoc, diag::warn_dangling_std_initializer_list)
2183            << /*at end of ctor*/1 << InitRange;
2184      }
2185    }
2186
2187    // Initialize the member.
2188    InitializedEntity MemberEntity =
2189      DirectMember ? InitializedEntity::InitializeMember(DirectMember, 0)
2190                   : InitializedEntity::InitializeMember(IndirectMember, 0);
2191    InitializationKind Kind =
2192      InitList ? InitializationKind::CreateDirectList(IdLoc)
2193               : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
2194                                                  InitRange.getEnd());
2195
2196    InitializationSequence InitSeq(*this, MemberEntity, Kind, Args, NumArgs);
2197    ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind,
2198                                            MultiExprArg(*this, Args, NumArgs),
2199                                            0);
2200    if (MemberInit.isInvalid())
2201      return true;
2202
2203    CheckImplicitConversions(MemberInit.get(),
2204                             InitRange.getBegin());
2205
2206    // C++0x [class.base.init]p7:
2207    //   The initialization of each base and member constitutes a
2208    //   full-expression.
2209    MemberInit = MaybeCreateExprWithCleanups(MemberInit);
2210    if (MemberInit.isInvalid())
2211      return true;
2212
2213    // If we are in a dependent context, template instantiation will
2214    // perform this type-checking again. Just save the arguments that we
2215    // received.
2216    // FIXME: This isn't quite ideal, since our ASTs don't capture all
2217    // of the information that we have about the member
2218    // initializer. However, deconstructing the ASTs is a dicey process,
2219    // and this approach is far more likely to get the corner cases right.
2220    if (CurContext->isDependentContext()) {
2221      // The existing Init will do fine.
2222    } else {
2223      Init = MemberInit.get();
2224      CheckForDanglingReferenceOrPointer(*this, Member, Init, IdLoc);
2225    }
2226  }
2227
2228  if (DirectMember) {
2229    return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
2230                                            InitRange.getBegin(), Init,
2231                                            InitRange.getEnd());
2232  } else {
2233    return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
2234                                            InitRange.getBegin(), Init,
2235                                            InitRange.getEnd());
2236  }
2237}
2238
2239MemInitResult
2240Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
2241                                 CXXRecordDecl *ClassDecl) {
2242  SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
2243  if (!LangOpts.CPlusPlus0x)
2244    return Diag(NameLoc, diag::err_delegating_ctor)
2245      << TInfo->getTypeLoc().getLocalSourceRange();
2246  Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
2247
2248  bool InitList = true;
2249  Expr **Args = &Init;
2250  unsigned NumArgs = 1;
2251  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
2252    InitList = false;
2253    Args = ParenList->getExprs();
2254    NumArgs = ParenList->getNumExprs();
2255  }
2256
2257  SourceRange InitRange = Init->getSourceRange();
2258  // Initialize the object.
2259  InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation(
2260                                     QualType(ClassDecl->getTypeForDecl(), 0));
2261  InitializationKind Kind =
2262    InitList ? InitializationKind::CreateDirectList(NameLoc)
2263             : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
2264                                                InitRange.getEnd());
2265  InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args, NumArgs);
2266  ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
2267                                              MultiExprArg(*this, Args,NumArgs),
2268                                              0);
2269  if (DelegationInit.isInvalid())
2270    return true;
2271
2272  assert(cast<CXXConstructExpr>(DelegationInit.get())->getConstructor() &&
2273         "Delegating constructor with no target?");
2274
2275  CheckImplicitConversions(DelegationInit.get(), InitRange.getBegin());
2276
2277  // C++0x [class.base.init]p7:
2278  //   The initialization of each base and member constitutes a
2279  //   full-expression.
2280  DelegationInit = MaybeCreateExprWithCleanups(DelegationInit);
2281  if (DelegationInit.isInvalid())
2282    return true;
2283
2284  // If we are in a dependent context, template instantiation will
2285  // perform this type-checking again. Just save the arguments that we
2286  // received in a ParenListExpr.
2287  // FIXME: This isn't quite ideal, since our ASTs don't capture all
2288  // of the information that we have about the base
2289  // initializer. However, deconstructing the ASTs is a dicey process,
2290  // and this approach is far more likely to get the corner cases right.
2291  if (CurContext->isDependentContext())
2292    DelegationInit = Owned(Init);
2293
2294  return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
2295                                          DelegationInit.takeAs<Expr>(),
2296                                          InitRange.getEnd());
2297}
2298
2299MemInitResult
2300Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
2301                           Expr *Init, CXXRecordDecl *ClassDecl,
2302                           SourceLocation EllipsisLoc) {
2303  SourceLocation BaseLoc
2304    = BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();
2305
2306  if (!BaseType->isDependentType() && !BaseType->isRecordType())
2307    return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
2308             << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
2309
2310  // C++ [class.base.init]p2:
2311  //   [...] Unless the mem-initializer-id names a nonstatic data
2312  //   member of the constructor's class or a direct or virtual base
2313  //   of that class, the mem-initializer is ill-formed. A
2314  //   mem-initializer-list can initialize a base class using any
2315  //   name that denotes that base class type.
2316  bool Dependent = BaseType->isDependentType() || Init->isTypeDependent();
2317
2318  SourceRange InitRange = Init->getSourceRange();
2319  if (EllipsisLoc.isValid()) {
2320    // This is a pack expansion.
2321    if (!BaseType->containsUnexpandedParameterPack())  {
2322      Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
2323        << SourceRange(BaseLoc, InitRange.getEnd());
2324
2325      EllipsisLoc = SourceLocation();
2326    }
2327  } else {
2328    // Check for any unexpanded parameter packs.
2329    if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
2330      return true;
2331
2332    if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
2333      return true;
2334  }
2335
2336  // Check for direct and virtual base classes.
2337  const CXXBaseSpecifier *DirectBaseSpec = 0;
2338  const CXXBaseSpecifier *VirtualBaseSpec = 0;
2339  if (!Dependent) {
2340    if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
2341                                       BaseType))
2342      return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);
2343
2344    FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
2345                        VirtualBaseSpec);
2346
2347    // C++ [base.class.init]p2:
2348    // Unless the mem-initializer-id names a nonstatic data member of the
2349    // constructor's class or a direct or virtual base of that class, the
2350    // mem-initializer is ill-formed.
2351    if (!DirectBaseSpec && !VirtualBaseSpec) {
2352      // If the class has any dependent bases, then it's possible that
2353      // one of those types will resolve to the same type as
2354      // BaseType. Therefore, just treat this as a dependent base
2355      // class initialization.  FIXME: Should we try to check the
2356      // initialization anyway? It seems odd.
2357      if (ClassDecl->hasAnyDependentBases())
2358        Dependent = true;
2359      else
2360        return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
2361          << BaseType << Context.getTypeDeclType(ClassDecl)
2362          << BaseTInfo->getTypeLoc().getLocalSourceRange();
2363    }
2364  }
2365
2366  if (Dependent) {
2367    DiscardCleanupsInEvaluationContext();
2368
2369    return new (Context) CXXCtorInitializer(Context, BaseTInfo,
2370                                            /*IsVirtual=*/false,
2371                                            InitRange.getBegin(), Init,
2372                                            InitRange.getEnd(), EllipsisLoc);
2373  }
2374
2375  // C++ [base.class.init]p2:
2376  //   If a mem-initializer-id is ambiguous because it designates both
2377  //   a direct non-virtual base class and an inherited virtual base
2378  //   class, the mem-initializer is ill-formed.
2379  if (DirectBaseSpec && VirtualBaseSpec)
2380    return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
2381      << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
2382
2383  CXXBaseSpecifier *BaseSpec = const_cast<CXXBaseSpecifier *>(DirectBaseSpec);
2384  if (!BaseSpec)
2385    BaseSpec = const_cast<CXXBaseSpecifier *>(VirtualBaseSpec);
2386
2387  // Initialize the base.
2388  bool InitList = true;
2389  Expr **Args = &Init;
2390  unsigned NumArgs = 1;
2391  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
2392    InitList = false;
2393    Args = ParenList->getExprs();
2394    NumArgs = ParenList->getNumExprs();
2395  }
2396
2397  InitializedEntity BaseEntity =
2398    InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
2399  InitializationKind Kind =
2400    InitList ? InitializationKind::CreateDirectList(BaseLoc)
2401             : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
2402                                                InitRange.getEnd());
2403  InitializationSequence InitSeq(*this, BaseEntity, Kind, Args, NumArgs);
2404  ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind,
2405                                          MultiExprArg(*this, Args, NumArgs),
2406                                          0);
2407  if (BaseInit.isInvalid())
2408    return true;
2409
2410  CheckImplicitConversions(BaseInit.get(), InitRange.getBegin());
2411
2412  // C++0x [class.base.init]p7:
2413  //   The initialization of each base and member constitutes a
2414  //   full-expression.
2415  BaseInit = MaybeCreateExprWithCleanups(BaseInit);
2416  if (BaseInit.isInvalid())
2417    return true;
2418
2419  // If we are in a dependent context, template instantiation will
2420  // perform this type-checking again. Just save the arguments that we
2421  // received in a ParenListExpr.
2422  // FIXME: This isn't quite ideal, since our ASTs don't capture all
2423  // of the information that we have about the base
2424  // initializer. However, deconstructing the ASTs is a dicey process,
2425  // and this approach is far more likely to get the corner cases right.
2426  if (CurContext->isDependentContext())
2427    BaseInit = Owned(Init);
2428
2429  return new (Context) CXXCtorInitializer(Context, BaseTInfo,
2430                                          BaseSpec->isVirtual(),
2431                                          InitRange.getBegin(),
2432                                          BaseInit.takeAs<Expr>(),
2433                                          InitRange.getEnd(), EllipsisLoc);
2434}
2435
2436// Create a static_cast\<T&&>(expr).
2437static Expr *CastForMoving(Sema &SemaRef, Expr *E) {
2438  QualType ExprType = E->getType();
2439  QualType TargetType = SemaRef.Context.getRValueReferenceType(ExprType);
2440  SourceLocation ExprLoc = E->getLocStart();
2441  TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
2442      TargetType, ExprLoc);
2443
2444  return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
2445                                   SourceRange(ExprLoc, ExprLoc),
2446                                   E->getSourceRange()).take();
2447}
2448
2449/// ImplicitInitializerKind - How an implicit base or member initializer should
2450/// initialize its base or member.
2451enum ImplicitInitializerKind {
2452  IIK_Default,
2453  IIK_Copy,
2454  IIK_Move
2455};
2456
2457static bool
2458BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
2459                             ImplicitInitializerKind ImplicitInitKind,
2460                             CXXBaseSpecifier *BaseSpec,
2461                             bool IsInheritedVirtualBase,
2462                             CXXCtorInitializer *&CXXBaseInit) {
2463  InitializedEntity InitEntity
2464    = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
2465                                        IsInheritedVirtualBase);
2466
2467  ExprResult BaseInit;
2468
2469  switch (ImplicitInitKind) {
2470  case IIK_Default: {
2471    InitializationKind InitKind
2472      = InitializationKind::CreateDefault(Constructor->getLocation());
2473    InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, 0, 0);
2474    BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind,
2475                               MultiExprArg(SemaRef, 0, 0));
2476    break;
2477  }
2478
2479  case IIK_Move:
2480  case IIK_Copy: {
2481    bool Moving = ImplicitInitKind == IIK_Move;
2482    ParmVarDecl *Param = Constructor->getParamDecl(0);
2483    QualType ParamType = Param->getType().getNonReferenceType();
2484
2485    Expr *CopyCtorArg =
2486      DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
2487                          SourceLocation(), Param, false,
2488                          Constructor->getLocation(), ParamType,
2489                          VK_LValue, 0);
2490
2491    SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));
2492
2493    // Cast to the base class to avoid ambiguities.
2494    QualType ArgTy =
2495      SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
2496                                       ParamType.getQualifiers());
2497
2498    if (Moving) {
2499      CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
2500    }
2501
2502    CXXCastPath BasePath;
2503    BasePath.push_back(BaseSpec);
2504    CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
2505                                            CK_UncheckedDerivedToBase,
2506                                            Moving ? VK_XValue : VK_LValue,
2507                                            &BasePath).take();
2508
2509    InitializationKind InitKind
2510      = InitializationKind::CreateDirect(Constructor->getLocation(),
2511                                         SourceLocation(), SourceLocation());
2512    InitializationSequence InitSeq(SemaRef, InitEntity, InitKind,
2513                                   &CopyCtorArg, 1);
2514    BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind,
2515                               MultiExprArg(&CopyCtorArg, 1));
2516    break;
2517  }
2518  }
2519
2520  BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
2521  if (BaseInit.isInvalid())
2522    return true;
2523
2524  CXXBaseInit =
2525    new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
2526               SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
2527                                                        SourceLocation()),
2528                                             BaseSpec->isVirtual(),
2529                                             SourceLocation(),
2530                                             BaseInit.takeAs<Expr>(),
2531                                             SourceLocation(),
2532                                             SourceLocation());
2533
2534  return false;
2535}
2536
2537static bool RefersToRValueRef(Expr *MemRef) {
2538  ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
2539  return Referenced->getType()->isRValueReferenceType();
2540}
2541
2542static bool
2543BuildImplicitMemberInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
2544                               ImplicitInitializerKind ImplicitInitKind,
2545                               FieldDecl *Field, IndirectFieldDecl *Indirect,
2546                               CXXCtorInitializer *&CXXMemberInit) {
2547  if (Field->isInvalidDecl())
2548    return true;
2549
2550  SourceLocation Loc = Constructor->getLocation();
2551
2552  if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
2553    bool Moving = ImplicitInitKind == IIK_Move;
2554    ParmVarDecl *Param = Constructor->getParamDecl(0);
2555    QualType ParamType = Param->getType().getNonReferenceType();
2556
2557    // Suppress copying zero-width bitfields.
2558    if (Field->isBitField() && Field->getBitWidthValue(SemaRef.Context) == 0)
2559      return false;
2560
2561    Expr *MemberExprBase =
2562      DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
2563                          SourceLocation(), Param, false,
2564                          Loc, ParamType, VK_LValue, 0);
2565
2566    SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));
2567
2568    if (Moving) {
2569      MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
2570    }
2571
2572    // Build a reference to this field within the parameter.
2573    CXXScopeSpec SS;
2574    LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
2575                              Sema::LookupMemberName);
2576    MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
2577                                  : cast<ValueDecl>(Field), AS_public);
2578    MemberLookup.resolveKind();
2579    ExprResult CtorArg
2580      = SemaRef.BuildMemberReferenceExpr(MemberExprBase,
2581                                         ParamType, Loc,
2582                                         /*IsArrow=*/false,
2583                                         SS,
2584                                         /*TemplateKWLoc=*/SourceLocation(),
2585                                         /*FirstQualifierInScope=*/0,
2586                                         MemberLookup,
2587                                         /*TemplateArgs=*/0);
2588    if (CtorArg.isInvalid())
2589      return true;
2590
2591    // C++11 [class.copy]p15:
2592    //   - if a member m has rvalue reference type T&&, it is direct-initialized
2593    //     with static_cast<T&&>(x.m);
2594    if (RefersToRValueRef(CtorArg.get())) {
2595      CtorArg = CastForMoving(SemaRef, CtorArg.take());
2596    }
2597
2598    // When the field we are copying is an array, create index variables for
2599    // each dimension of the array. We use these index variables to subscript
2600    // the source array, and other clients (e.g., CodeGen) will perform the
2601    // necessary iteration with these index variables.
2602    SmallVector<VarDecl *, 4> IndexVariables;
2603    QualType BaseType = Field->getType();
2604    QualType SizeType = SemaRef.Context.getSizeType();
2605    bool InitializingArray = false;
2606    while (const ConstantArrayType *Array
2607                          = SemaRef.Context.getAsConstantArrayType(BaseType)) {
2608      InitializingArray = true;
2609      // Create the iteration variable for this array index.
2610      IdentifierInfo *IterationVarName = 0;
2611      {
2612        SmallString<8> Str;
2613        llvm::raw_svector_ostream OS(Str);
2614        OS << "__i" << IndexVariables.size();
2615        IterationVarName = &SemaRef.Context.Idents.get(OS.str());
2616      }
2617      VarDecl *IterationVar
2618        = VarDecl::Create(SemaRef.Context, SemaRef.CurContext, Loc, Loc,
2619                          IterationVarName, SizeType,
2620                        SemaRef.Context.getTrivialTypeSourceInfo(SizeType, Loc),
2621                          SC_None, SC_None);
2622      IndexVariables.push_back(IterationVar);
2623
2624      // Create a reference to the iteration variable.
2625      ExprResult IterationVarRef
2626        = SemaRef.BuildDeclRefExpr(IterationVar, SizeType, VK_LValue, Loc);
2627      assert(!IterationVarRef.isInvalid() &&
2628             "Reference to invented variable cannot fail!");
2629      IterationVarRef = SemaRef.DefaultLvalueConversion(IterationVarRef.take());
2630      assert(!IterationVarRef.isInvalid() &&
2631             "Conversion of invented variable cannot fail!");
2632
2633      // Subscript the array with this iteration variable.
2634      CtorArg = SemaRef.CreateBuiltinArraySubscriptExpr(CtorArg.take(), Loc,
2635                                                        IterationVarRef.take(),
2636                                                        Loc);
2637      if (CtorArg.isInvalid())
2638        return true;
2639
2640      BaseType = Array->getElementType();
2641    }
2642
2643    // The array subscript expression is an lvalue, which is wrong for moving.
2644    if (Moving && InitializingArray)
2645      CtorArg = CastForMoving(SemaRef, CtorArg.take());
2646
2647    // Construct the entity that we will be initializing. For an array, this
2648    // will be first element in the array, which may require several levels
2649    // of array-subscript entities.
2650    SmallVector<InitializedEntity, 4> Entities;
2651    Entities.reserve(1 + IndexVariables.size());
2652    if (Indirect)
2653      Entities.push_back(InitializedEntity::InitializeMember(Indirect));
2654    else
2655      Entities.push_back(InitializedEntity::InitializeMember(Field));
2656    for (unsigned I = 0, N = IndexVariables.size(); I != N; ++I)
2657      Entities.push_back(InitializedEntity::InitializeElement(SemaRef.Context,
2658                                                              0,
2659                                                              Entities.back()));
2660
2661    // Direct-initialize to use the copy constructor.
2662    InitializationKind InitKind =
2663      InitializationKind::CreateDirect(Loc, SourceLocation(), SourceLocation());
2664
2665    Expr *CtorArgE = CtorArg.takeAs<Expr>();
2666    InitializationSequence InitSeq(SemaRef, Entities.back(), InitKind,
2667                                   &CtorArgE, 1);
2668
2669    ExprResult MemberInit
2670      = InitSeq.Perform(SemaRef, Entities.back(), InitKind,
2671                        MultiExprArg(&CtorArgE, 1));
2672    MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
2673    if (MemberInit.isInvalid())
2674      return true;
2675
2676    if (Indirect) {
2677      assert(IndexVariables.size() == 0 &&
2678             "Indirect field improperly initialized");
2679      CXXMemberInit
2680        = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Indirect,
2681                                                   Loc, Loc,
2682                                                   MemberInit.takeAs<Expr>(),
2683                                                   Loc);
2684    } else
2685      CXXMemberInit = CXXCtorInitializer::Create(SemaRef.Context, Field, Loc,
2686                                                 Loc, MemberInit.takeAs<Expr>(),
2687                                                 Loc,
2688                                                 IndexVariables.data(),
2689                                                 IndexVariables.size());
2690    return false;
2691  }
2692
2693  assert(ImplicitInitKind == IIK_Default && "Unhandled implicit init kind!");
2694
2695  QualType FieldBaseElementType =
2696    SemaRef.Context.getBaseElementType(Field->getType());
2697
2698  if (FieldBaseElementType->isRecordType()) {
2699    InitializedEntity InitEntity
2700      = Indirect? InitializedEntity::InitializeMember(Indirect)
2701                : InitializedEntity::InitializeMember(Field);
2702    InitializationKind InitKind =
2703      InitializationKind::CreateDefault(Loc);
2704
2705    InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, 0, 0);
2706    ExprResult MemberInit =
2707      InitSeq.Perform(SemaRef, InitEntity, InitKind, MultiExprArg());
2708
2709    MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
2710    if (MemberInit.isInvalid())
2711      return true;
2712
2713    if (Indirect)
2714      CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
2715                                                               Indirect, Loc,
2716                                                               Loc,
2717                                                               MemberInit.get(),
2718                                                               Loc);
2719    else
2720      CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
2721                                                               Field, Loc, Loc,
2722                                                               MemberInit.get(),
2723                                                               Loc);
2724    return false;
2725  }
2726
2727  if (!Field->getParent()->isUnion()) {
2728    if (FieldBaseElementType->isReferenceType()) {
2729      SemaRef.Diag(Constructor->getLocation(),
2730                   diag::err_uninitialized_member_in_ctor)
2731      << (int)Constructor->isImplicit()
2732      << SemaRef.Context.getTagDeclType(Constructor->getParent())
2733      << 0 << Field->getDeclName();
2734      SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
2735      return true;
2736    }
2737
2738    if (FieldBaseElementType.isConstQualified()) {
2739      SemaRef.Diag(Constructor->getLocation(),
2740                   diag::err_uninitialized_member_in_ctor)
2741      << (int)Constructor->isImplicit()
2742      << SemaRef.Context.getTagDeclType(Constructor->getParent())
2743      << 1 << Field->getDeclName();
2744      SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
2745      return true;
2746    }
2747  }
2748
2749  if (SemaRef.getLangOpts().ObjCAutoRefCount &&
2750      FieldBaseElementType->isObjCRetainableType() &&
2751      FieldBaseElementType.getObjCLifetime() != Qualifiers::OCL_None &&
2752      FieldBaseElementType.getObjCLifetime() != Qualifiers::OCL_ExplicitNone) {
2753    // Instant objects:
2754    //   Default-initialize Objective-C pointers to NULL.
2755    CXXMemberInit
2756      = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
2757                                                 Loc, Loc,
2758                 new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
2759                                                 Loc);
2760    return false;
2761  }
2762
2763  // Nothing to initialize.
2764  CXXMemberInit = 0;
2765  return false;
2766}
2767
2768namespace {
2769struct BaseAndFieldInfo {
2770  Sema &S;
2771  CXXConstructorDecl *Ctor;
2772  bool AnyErrorsInInits;
2773  ImplicitInitializerKind IIK;
2774  llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
2775  SmallVector<CXXCtorInitializer*, 8> AllToInit;
2776
2777  BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
2778    : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
2779    bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
2780    if (Generated && Ctor->isCopyConstructor())
2781      IIK = IIK_Copy;
2782    else if (Generated && Ctor->isMoveConstructor())
2783      IIK = IIK_Move;
2784    else
2785      IIK = IIK_Default;
2786  }
2787
2788  bool isImplicitCopyOrMove() const {
2789    switch (IIK) {
2790    case IIK_Copy:
2791    case IIK_Move:
2792      return true;
2793
2794    case IIK_Default:
2795      return false;
2796    }
2797
2798    llvm_unreachable("Invalid ImplicitInitializerKind!");
2799  }
2800};
2801}
2802
2803/// \brief Determine whether the given indirect field declaration is somewhere
2804/// within an anonymous union.
2805static bool isWithinAnonymousUnion(IndirectFieldDecl *F) {
2806  for (IndirectFieldDecl::chain_iterator C = F->chain_begin(),
2807                                      CEnd = F->chain_end();
2808       C != CEnd; ++C)
2809    if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>((*C)->getDeclContext()))
2810      if (Record->isUnion())
2811        return true;
2812
2813  return false;
2814}
2815
2816/// \brief Determine whether the given type is an incomplete or zero-lenfgth
2817/// array type.
2818static bool isIncompleteOrZeroLengthArrayType(ASTContext &Context, QualType T) {
2819  if (T->isIncompleteArrayType())
2820    return true;
2821
2822  while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
2823    if (!ArrayT->getSize())
2824      return true;
2825
2826    T = ArrayT->getElementType();
2827  }
2828
2829  return false;
2830}
2831
2832static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
2833                                    FieldDecl *Field,
2834                                    IndirectFieldDecl *Indirect = 0) {
2835
2836  // Overwhelmingly common case: we have a direct initializer for this field.
2837  if (CXXCtorInitializer *Init = Info.AllBaseFields.lookup(Field)) {
2838    Info.AllToInit.push_back(Init);
2839    return false;
2840  }
2841
2842  // C++0x [class.base.init]p8: if the entity is a non-static data member that
2843  // has a brace-or-equal-initializer, the entity is initialized as specified
2844  // in [dcl.init].
2845  if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
2846    CXXCtorInitializer *Init;
2847    if (Indirect)
2848      Init = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Indirect,
2849                                                      SourceLocation(),
2850                                                      SourceLocation(), 0,
2851                                                      SourceLocation());
2852    else
2853      Init = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
2854                                                      SourceLocation(),
2855                                                      SourceLocation(), 0,
2856                                                      SourceLocation());
2857    Info.AllToInit.push_back(Init);
2858
2859    // Check whether this initializer makes the field "used".
2860    Expr *InitExpr = Field->getInClassInitializer();
2861    if (Field->getType()->isRecordType() ||
2862        (InitExpr && InitExpr->HasSideEffects(SemaRef.Context)))
2863      SemaRef.UnusedPrivateFields.remove(Field);
2864
2865    return false;
2866  }
2867
2868  // Don't build an implicit initializer for union members if none was
2869  // explicitly specified.
2870  if (Field->getParent()->isUnion() ||
2871      (Indirect && isWithinAnonymousUnion(Indirect)))
2872    return false;
2873
2874  // Don't initialize incomplete or zero-length arrays.
2875  if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
2876    return false;
2877
2878  // Don't try to build an implicit initializer if there were semantic
2879  // errors in any of the initializers (and therefore we might be
2880  // missing some that the user actually wrote).
2881  if (Info.AnyErrorsInInits || Field->isInvalidDecl())
2882    return false;
2883
2884  CXXCtorInitializer *Init = 0;
2885  if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
2886                                     Indirect, Init))
2887    return true;
2888
2889  if (Init)
2890    Info.AllToInit.push_back(Init);
2891
2892  return false;
2893}
2894
2895bool
2896Sema::SetDelegatingInitializer(CXXConstructorDecl *Constructor,
2897                               CXXCtorInitializer *Initializer) {
2898  assert(Initializer->isDelegatingInitializer());
2899  Constructor->setNumCtorInitializers(1);
2900  CXXCtorInitializer **initializer =
2901    new (Context) CXXCtorInitializer*[1];
2902  memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
2903  Constructor->setCtorInitializers(initializer);
2904
2905  if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
2906    MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
2907    DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
2908  }
2909
2910  DelegatingCtorDecls.push_back(Constructor);
2911
2912  return false;
2913}
2914
2915bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor,
2916                               CXXCtorInitializer **Initializers,
2917                               unsigned NumInitializers,
2918                               bool AnyErrors) {
2919  if (Constructor->isDependentContext()) {
2920    // Just store the initializers as written, they will be checked during
2921    // instantiation.
2922    if (NumInitializers > 0) {
2923      Constructor->setNumCtorInitializers(NumInitializers);
2924      CXXCtorInitializer **baseOrMemberInitializers =
2925        new (Context) CXXCtorInitializer*[NumInitializers];
2926      memcpy(baseOrMemberInitializers, Initializers,
2927             NumInitializers * sizeof(CXXCtorInitializer*));
2928      Constructor->setCtorInitializers(baseOrMemberInitializers);
2929    }
2930
2931    return false;
2932  }
2933
2934  BaseAndFieldInfo Info(*this, Constructor, AnyErrors);
2935
2936  // We need to build the initializer AST according to order of construction
2937  // and not what user specified in the Initializers list.
2938  CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
2939  if (!ClassDecl)
2940    return true;
2941
2942  bool HadError = false;
2943
2944  for (unsigned i = 0; i < NumInitializers; i++) {
2945    CXXCtorInitializer *Member = Initializers[i];
2946
2947    if (Member->isBaseInitializer())
2948      Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
2949    else
2950      Info.AllBaseFields[Member->getAnyMember()] = Member;
2951  }
2952
2953  // Keep track of the direct virtual bases.
2954  llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
2955  for (CXXRecordDecl::base_class_iterator I = ClassDecl->bases_begin(),
2956       E = ClassDecl->bases_end(); I != E; ++I) {
2957    if (I->isVirtual())
2958      DirectVBases.insert(I);
2959  }
2960
2961  // Push virtual bases before others.
2962  for (CXXRecordDecl::base_class_iterator VBase = ClassDecl->vbases_begin(),
2963       E = ClassDecl->vbases_end(); VBase != E; ++VBase) {
2964
2965    if (CXXCtorInitializer *Value
2966        = Info.AllBaseFields.lookup(VBase->getType()->getAs<RecordType>())) {
2967      Info.AllToInit.push_back(Value);
2968    } else if (!AnyErrors) {
2969      bool IsInheritedVirtualBase = !DirectVBases.count(VBase);
2970      CXXCtorInitializer *CXXBaseInit;
2971      if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
2972                                       VBase, IsInheritedVirtualBase,
2973                                       CXXBaseInit)) {
2974        HadError = true;
2975        continue;
2976      }
2977
2978      Info.AllToInit.push_back(CXXBaseInit);
2979    }
2980  }
2981
2982  // Non-virtual bases.
2983  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
2984       E = ClassDecl->bases_end(); Base != E; ++Base) {
2985    // Virtuals are in the virtual base list and already constructed.
2986    if (Base->isVirtual())
2987      continue;
2988
2989    if (CXXCtorInitializer *Value
2990          = Info.AllBaseFields.lookup(Base->getType()->getAs<RecordType>())) {
2991      Info.AllToInit.push_back(Value);
2992    } else if (!AnyErrors) {
2993      CXXCtorInitializer *CXXBaseInit;
2994      if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
2995                                       Base, /*IsInheritedVirtualBase=*/false,
2996                                       CXXBaseInit)) {
2997        HadError = true;
2998        continue;
2999      }
3000
3001      Info.AllToInit.push_back(CXXBaseInit);
3002    }
3003  }
3004
3005  // Fields.
3006  for (DeclContext::decl_iterator Mem = ClassDecl->decls_begin(),
3007                               MemEnd = ClassDecl->decls_end();
3008       Mem != MemEnd; ++Mem) {
3009    if (FieldDecl *F = dyn_cast<FieldDecl>(*Mem)) {
3010      // C++ [class.bit]p2:
3011      //   A declaration for a bit-field that omits the identifier declares an
3012      //   unnamed bit-field. Unnamed bit-fields are not members and cannot be
3013      //   initialized.
3014      if (F->isUnnamedBitfield())
3015        continue;
3016
3017      // If we're not generating the implicit copy/move constructor, then we'll
3018      // handle anonymous struct/union fields based on their individual
3019      // indirect fields.
3020      if (F->isAnonymousStructOrUnion() && Info.IIK == IIK_Default)
3021        continue;
3022
3023      if (CollectFieldInitializer(*this, Info, F))
3024        HadError = true;
3025      continue;
3026    }
3027
3028    // Beyond this point, we only consider default initialization.
3029    if (Info.IIK != IIK_Default)
3030      continue;
3031
3032    if (IndirectFieldDecl *F = dyn_cast<IndirectFieldDecl>(*Mem)) {
3033      if (F->getType()->isIncompleteArrayType()) {
3034        assert(ClassDecl->hasFlexibleArrayMember() &&
3035               "Incomplete array type is not valid");
3036        continue;
3037      }
3038
3039      // Initialize each field of an anonymous struct individually.
3040      if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
3041        HadError = true;
3042
3043      continue;
3044    }
3045  }
3046
3047  NumInitializers = Info.AllToInit.size();
3048  if (NumInitializers > 0) {
3049    Constructor->setNumCtorInitializers(NumInitializers);
3050    CXXCtorInitializer **baseOrMemberInitializers =
3051      new (Context) CXXCtorInitializer*[NumInitializers];
3052    memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
3053           NumInitializers * sizeof(CXXCtorInitializer*));
3054    Constructor->setCtorInitializers(baseOrMemberInitializers);
3055
3056    // Constructors implicitly reference the base and member
3057    // destructors.
3058    MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
3059                                           Constructor->getParent());
3060  }
3061
3062  return HadError;
3063}
3064
3065static void *GetKeyForTopLevelField(FieldDecl *Field) {
3066  // For anonymous unions, use the class declaration as the key.
3067  if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
3068    if (RT->getDecl()->isAnonymousStructOrUnion())
3069      return static_cast<void *>(RT->getDecl());
3070  }
3071  return static_cast<void *>(Field);
3072}
3073
3074static void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
3075  return const_cast<Type*>(Context.getCanonicalType(BaseType).getTypePtr());
3076}
3077
3078static void *GetKeyForMember(ASTContext &Context,
3079                             CXXCtorInitializer *Member) {
3080  if (!Member->isAnyMemberInitializer())
3081    return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));
3082
3083  // For fields injected into the class via declaration of an anonymous union,
3084  // use its anonymous union class declaration as the unique key.
3085  FieldDecl *Field = Member->getAnyMember();
3086
3087  // If the field is a member of an anonymous struct or union, our key
3088  // is the anonymous record decl that's a direct child of the class.
3089  RecordDecl *RD = Field->getParent();
3090  if (RD->isAnonymousStructOrUnion()) {
3091    while (true) {
3092      RecordDecl *Parent = cast<RecordDecl>(RD->getDeclContext());
3093      if (Parent->isAnonymousStructOrUnion())
3094        RD = Parent;
3095      else
3096        break;
3097    }
3098
3099    return static_cast<void *>(RD);
3100  }
3101
3102  return static_cast<void *>(Field);
3103}
3104
3105static void
3106DiagnoseBaseOrMemInitializerOrder(Sema &SemaRef,
3107                                  const CXXConstructorDecl *Constructor,
3108                                  CXXCtorInitializer **Inits,
3109                                  unsigned NumInits) {
3110  if (Constructor->getDeclContext()->isDependentContext())
3111    return;
3112
3113  // Don't check initializers order unless the warning is enabled at the
3114  // location of at least one initializer.
3115  bool ShouldCheckOrder = false;
3116  for (unsigned InitIndex = 0; InitIndex != NumInits; ++InitIndex) {
3117    CXXCtorInitializer *Init = Inits[InitIndex];
3118    if (SemaRef.Diags.getDiagnosticLevel(diag::warn_initializer_out_of_order,
3119                                         Init->getSourceLocation())
3120          != DiagnosticsEngine::Ignored) {
3121      ShouldCheckOrder = true;
3122      break;
3123    }
3124  }
3125  if (!ShouldCheckOrder)
3126    return;
3127
3128  // Build the list of bases and members in the order that they'll
3129  // actually be initialized.  The explicit initializers should be in
3130  // this same order but may be missing things.
3131  SmallVector<const void*, 32> IdealInitKeys;
3132
3133  const CXXRecordDecl *ClassDecl = Constructor->getParent();
3134
3135  // 1. Virtual bases.
3136  for (CXXRecordDecl::base_class_const_iterator VBase =
3137       ClassDecl->vbases_begin(),
3138       E = ClassDecl->vbases_end(); VBase != E; ++VBase)
3139    IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase->getType()));
3140
3141  // 2. Non-virtual bases.
3142  for (CXXRecordDecl::base_class_const_iterator Base = ClassDecl->bases_begin(),
3143       E = ClassDecl->bases_end(); Base != E; ++Base) {
3144    if (Base->isVirtual())
3145      continue;
3146    IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base->getType()));
3147  }
3148
3149  // 3. Direct fields.
3150  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
3151       E = ClassDecl->field_end(); Field != E; ++Field) {
3152    if (Field->isUnnamedBitfield())
3153      continue;
3154
3155    IdealInitKeys.push_back(GetKeyForTopLevelField(*Field));
3156  }
3157
3158  unsigned NumIdealInits = IdealInitKeys.size();
3159  unsigned IdealIndex = 0;
3160
3161  CXXCtorInitializer *PrevInit = 0;
3162  for (unsigned InitIndex = 0; InitIndex != NumInits; ++InitIndex) {
3163    CXXCtorInitializer *Init = Inits[InitIndex];
3164    void *InitKey = GetKeyForMember(SemaRef.Context, Init);
3165
3166    // Scan forward to try to find this initializer in the idealized
3167    // initializers list.
3168    for (; IdealIndex != NumIdealInits; ++IdealIndex)
3169      if (InitKey == IdealInitKeys[IdealIndex])
3170        break;
3171
3172    // If we didn't find this initializer, it must be because we
3173    // scanned past it on a previous iteration.  That can only
3174    // happen if we're out of order;  emit a warning.
3175    if (IdealIndex == NumIdealInits && PrevInit) {
3176      Sema::SemaDiagnosticBuilder D =
3177        SemaRef.Diag(PrevInit->getSourceLocation(),
3178                     diag::warn_initializer_out_of_order);
3179
3180      if (PrevInit->isAnyMemberInitializer())
3181        D << 0 << PrevInit->getAnyMember()->getDeclName();
3182      else
3183        D << 1 << PrevInit->getTypeSourceInfo()->getType();
3184
3185      if (Init->isAnyMemberInitializer())
3186        D << 0 << Init->getAnyMember()->getDeclName();
3187      else
3188        D << 1 << Init->getTypeSourceInfo()->getType();
3189
3190      // Move back to the initializer's location in the ideal list.
3191      for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
3192        if (InitKey == IdealInitKeys[IdealIndex])
3193          break;
3194
3195      assert(IdealIndex != NumIdealInits &&
3196             "initializer not found in initializer list");
3197    }
3198
3199    PrevInit = Init;
3200  }
3201}
3202
3203namespace {
3204bool CheckRedundantInit(Sema &S,
3205                        CXXCtorInitializer *Init,
3206                        CXXCtorInitializer *&PrevInit) {
3207  if (!PrevInit) {
3208    PrevInit = Init;
3209    return false;
3210  }
3211
3212  if (FieldDecl *Field = Init->getMember())
3213    S.Diag(Init->getSourceLocation(),
3214           diag::err_multiple_mem_initialization)
3215      << Field->getDeclName()
3216      << Init->getSourceRange();
3217  else {
3218    const Type *BaseClass = Init->getBaseClass();
3219    assert(BaseClass && "neither field nor base");
3220    S.Diag(Init->getSourceLocation(),
3221           diag::err_multiple_base_initialization)
3222      << QualType(BaseClass, 0)
3223      << Init->getSourceRange();
3224  }
3225  S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
3226    << 0 << PrevInit->getSourceRange();
3227
3228  return true;
3229}
3230
3231typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
3232typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;
3233
3234bool CheckRedundantUnionInit(Sema &S,
3235                             CXXCtorInitializer *Init,
3236                             RedundantUnionMap &Unions) {
3237  FieldDecl *Field = Init->getAnyMember();
3238  RecordDecl *Parent = Field->getParent();
3239  NamedDecl *Child = Field;
3240
3241  while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
3242    if (Parent->isUnion()) {
3243      UnionEntry &En = Unions[Parent];
3244      if (En.first && En.first != Child) {
3245        S.Diag(Init->getSourceLocation(),
3246               diag::err_multiple_mem_union_initialization)
3247          << Field->getDeclName()
3248          << Init->getSourceRange();
3249        S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
3250          << 0 << En.second->getSourceRange();
3251        return true;
3252      }
3253      if (!En.first) {
3254        En.first = Child;
3255        En.second = Init;
3256      }
3257      if (!Parent->isAnonymousStructOrUnion())
3258        return false;
3259    }
3260
3261    Child = Parent;
3262    Parent = cast<RecordDecl>(Parent->getDeclContext());
3263  }
3264
3265  return false;
3266}
3267}
3268
3269/// ActOnMemInitializers - Handle the member initializers for a constructor.
3270void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
3271                                SourceLocation ColonLoc,
3272                                CXXCtorInitializer **meminits,
3273                                unsigned NumMemInits,
3274                                bool AnyErrors) {
3275  if (!ConstructorDecl)
3276    return;
3277
3278  AdjustDeclIfTemplate(ConstructorDecl);
3279
3280  CXXConstructorDecl *Constructor
3281    = dyn_cast<CXXConstructorDecl>(ConstructorDecl);
3282
3283  if (!Constructor) {
3284    Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
3285    return;
3286  }
3287
3288  CXXCtorInitializer **MemInits =
3289    reinterpret_cast<CXXCtorInitializer **>(meminits);
3290
3291  // Mapping for the duplicate initializers check.
3292  // For member initializers, this is keyed with a FieldDecl*.
3293  // For base initializers, this is keyed with a Type*.
3294  llvm::DenseMap<void*, CXXCtorInitializer *> Members;
3295
3296  // Mapping for the inconsistent anonymous-union initializers check.
3297  RedundantUnionMap MemberUnions;
3298
3299  bool HadError = false;
3300  for (unsigned i = 0; i < NumMemInits; i++) {
3301    CXXCtorInitializer *Init = MemInits[i];
3302
3303    // Set the source order index.
3304    Init->setSourceOrder(i);
3305
3306    if (Init->isAnyMemberInitializer()) {
3307      FieldDecl *Field = Init->getAnyMember();
3308      if (CheckRedundantInit(*this, Init, Members[Field]) ||
3309          CheckRedundantUnionInit(*this, Init, MemberUnions))
3310        HadError = true;
3311    } else if (Init->isBaseInitializer()) {
3312      void *Key = GetKeyForBase(Context, QualType(Init->getBaseClass(), 0));
3313      if (CheckRedundantInit(*this, Init, Members[Key]))
3314        HadError = true;
3315    } else {
3316      assert(Init->isDelegatingInitializer());
3317      // This must be the only initializer
3318      if (i != 0 || NumMemInits > 1) {
3319        Diag(MemInits[0]->getSourceLocation(),
3320             diag::err_delegating_initializer_alone)
3321          << MemInits[0]->getSourceRange();
3322        HadError = true;
3323        // We will treat this as being the only initializer.
3324      }
3325      SetDelegatingInitializer(Constructor, MemInits[i]);
3326      // Return immediately as the initializer is set.
3327      return;
3328    }
3329  }
3330
3331  if (HadError)
3332    return;
3333
3334  DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits, NumMemInits);
3335
3336  SetCtorInitializers(Constructor, MemInits, NumMemInits, AnyErrors);
3337}
3338
3339void
3340Sema::MarkBaseAndMemberDestructorsReferenced(SourceLocation Location,
3341                                             CXXRecordDecl *ClassDecl) {
3342  // Ignore dependent contexts. Also ignore unions, since their members never
3343  // have destructors implicitly called.
3344  if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
3345    return;
3346
3347  // FIXME: all the access-control diagnostics are positioned on the
3348  // field/base declaration.  That's probably good; that said, the
3349  // user might reasonably want to know why the destructor is being
3350  // emitted, and we currently don't say.
3351
3352  // Non-static data members.
3353  for (CXXRecordDecl::field_iterator I = ClassDecl->field_begin(),
3354       E = ClassDecl->field_end(); I != E; ++I) {
3355    FieldDecl *Field = *I;
3356    if (Field->isInvalidDecl())
3357      continue;
3358
3359    // Don't destroy incomplete or zero-length arrays.
3360    if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
3361      continue;
3362
3363    QualType FieldType = Context.getBaseElementType(Field->getType());
3364
3365    const RecordType* RT = FieldType->getAs<RecordType>();
3366    if (!RT)
3367      continue;
3368
3369    CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
3370    if (FieldClassDecl->isInvalidDecl())
3371      continue;
3372    if (FieldClassDecl->hasIrrelevantDestructor())
3373      continue;
3374    // The destructor for an implicit anonymous union member is never invoked.
3375    if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
3376      continue;
3377
3378    CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
3379    assert(Dtor && "No dtor found for FieldClassDecl!");
3380    CheckDestructorAccess(Field->getLocation(), Dtor,
3381                          PDiag(diag::err_access_dtor_field)
3382                            << Field->getDeclName()
3383                            << FieldType);
3384
3385    MarkFunctionReferenced(Location, const_cast<CXXDestructorDecl*>(Dtor));
3386    DiagnoseUseOfDecl(Dtor, Location);
3387  }
3388
3389  llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;
3390
3391  // Bases.
3392  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
3393       E = ClassDecl->bases_end(); Base != E; ++Base) {
3394    // Bases are always records in a well-formed non-dependent class.
3395    const RecordType *RT = Base->getType()->getAs<RecordType>();
3396
3397    // Remember direct virtual bases.
3398    if (Base->isVirtual())
3399      DirectVirtualBases.insert(RT);
3400
3401    CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
3402    // If our base class is invalid, we probably can't get its dtor anyway.
3403    if (BaseClassDecl->isInvalidDecl())
3404      continue;
3405    if (BaseClassDecl->hasIrrelevantDestructor())
3406      continue;
3407
3408    CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
3409    assert(Dtor && "No dtor found for BaseClassDecl!");
3410
3411    // FIXME: caret should be on the start of the class name
3412    CheckDestructorAccess(Base->getLocStart(), Dtor,
3413                          PDiag(diag::err_access_dtor_base)
3414                            << Base->getType()
3415                            << Base->getSourceRange(),
3416                          Context.getTypeDeclType(ClassDecl));
3417
3418    MarkFunctionReferenced(Location, const_cast<CXXDestructorDecl*>(Dtor));
3419    DiagnoseUseOfDecl(Dtor, Location);
3420  }
3421
3422  // Virtual bases.
3423  for (CXXRecordDecl::base_class_iterator VBase = ClassDecl->vbases_begin(),
3424       E = ClassDecl->vbases_end(); VBase != E; ++VBase) {
3425
3426    // Bases are always records in a well-formed non-dependent class.
3427    const RecordType *RT = VBase->getType()->castAs<RecordType>();
3428
3429    // Ignore direct virtual bases.
3430    if (DirectVirtualBases.count(RT))
3431      continue;
3432
3433    CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
3434    // If our base class is invalid, we probably can't get its dtor anyway.
3435    if (BaseClassDecl->isInvalidDecl())
3436      continue;
3437    if (BaseClassDecl->hasIrrelevantDestructor())
3438      continue;
3439
3440    CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
3441    assert(Dtor && "No dtor found for BaseClassDecl!");
3442    CheckDestructorAccess(ClassDecl->getLocation(), Dtor,
3443                          PDiag(diag::err_access_dtor_vbase)
3444                            << VBase->getType(),
3445                          Context.getTypeDeclType(ClassDecl));
3446
3447    MarkFunctionReferenced(Location, const_cast<CXXDestructorDecl*>(Dtor));
3448    DiagnoseUseOfDecl(Dtor, Location);
3449  }
3450}
3451
3452void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
3453  if (!CDtorDecl)
3454    return;
3455
3456  if (CXXConstructorDecl *Constructor
3457      = dyn_cast<CXXConstructorDecl>(CDtorDecl))
3458    SetCtorInitializers(Constructor, 0, 0, /*AnyErrors=*/false);
3459}
3460
3461bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
3462                                  unsigned DiagID, AbstractDiagSelID SelID) {
3463  class NonAbstractTypeDiagnoser : public TypeDiagnoser {
3464    unsigned DiagID;
3465    AbstractDiagSelID SelID;
3466
3467  public:
3468    NonAbstractTypeDiagnoser(unsigned DiagID, AbstractDiagSelID SelID)
3469      : TypeDiagnoser(DiagID == 0), DiagID(DiagID), SelID(SelID) { }
3470
3471    virtual void diagnose(Sema &S, SourceLocation Loc, QualType T) {
3472      if (SelID == -1)
3473        S.Diag(Loc, DiagID) << T;
3474      else
3475        S.Diag(Loc, DiagID) << SelID << T;
3476    }
3477  } Diagnoser(DiagID, SelID);
3478
3479  return RequireNonAbstractType(Loc, T, Diagnoser);
3480}
3481
3482bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
3483                                  TypeDiagnoser &Diagnoser) {
3484  if (!getLangOpts().CPlusPlus)
3485    return false;
3486
3487  if (const ArrayType *AT = Context.getAsArrayType(T))
3488    return RequireNonAbstractType(Loc, AT->getElementType(), Diagnoser);
3489
3490  if (const PointerType *PT = T->getAs<PointerType>()) {
3491    // Find the innermost pointer type.
3492    while (const PointerType *T = PT->getPointeeType()->getAs<PointerType>())
3493      PT = T;
3494
3495    if (const ArrayType *AT = Context.getAsArrayType(PT->getPointeeType()))
3496      return RequireNonAbstractType(Loc, AT->getElementType(), Diagnoser);
3497  }
3498
3499  const RecordType *RT = T->getAs<RecordType>();
3500  if (!RT)
3501    return false;
3502
3503  const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
3504
3505  // We can't answer whether something is abstract until it has a
3506  // definition.  If it's currently being defined, we'll walk back
3507  // over all the declarations when we have a full definition.
3508  const CXXRecordDecl *Def = RD->getDefinition();
3509  if (!Def || Def->isBeingDefined())
3510    return false;
3511
3512  if (!RD->isAbstract())
3513    return false;
3514
3515  Diagnoser.diagnose(*this, Loc, T);
3516  DiagnoseAbstractType(RD);
3517
3518  return true;
3519}
3520
3521void Sema::DiagnoseAbstractType(const CXXRecordDecl *RD) {
3522  // Check if we've already emitted the list of pure virtual functions
3523  // for this class.
3524  if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
3525    return;
3526
3527  CXXFinalOverriderMap FinalOverriders;
3528  RD->getFinalOverriders(FinalOverriders);
3529
3530  // Keep a set of seen pure methods so we won't diagnose the same method
3531  // more than once.
3532  llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;
3533
3534  for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
3535                                   MEnd = FinalOverriders.end();
3536       M != MEnd;
3537       ++M) {
3538    for (OverridingMethods::iterator SO = M->second.begin(),
3539                                  SOEnd = M->second.end();
3540         SO != SOEnd; ++SO) {
3541      // C++ [class.abstract]p4:
3542      //   A class is abstract if it contains or inherits at least one
3543      //   pure virtual function for which the final overrider is pure
3544      //   virtual.
3545
3546      //
3547      if (SO->second.size() != 1)
3548        continue;
3549
3550      if (!SO->second.front().Method->isPure())
3551        continue;
3552
3553      if (!SeenPureMethods.insert(SO->second.front().Method))
3554        continue;
3555
3556      Diag(SO->second.front().Method->getLocation(),
3557           diag::note_pure_virtual_function)
3558        << SO->second.front().Method->getDeclName() << RD->getDeclName();
3559    }
3560  }
3561
3562  if (!PureVirtualClassDiagSet)
3563    PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
3564  PureVirtualClassDiagSet->insert(RD);
3565}
3566
3567namespace {
3568struct AbstractUsageInfo {
3569  Sema &S;
3570  CXXRecordDecl *Record;
3571  CanQualType AbstractType;
3572  bool Invalid;
3573
3574  AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
3575    : S(S), Record(Record),
3576      AbstractType(S.Context.getCanonicalType(
3577                   S.Context.getTypeDeclType(Record))),
3578      Invalid(false) {}
3579
3580  void DiagnoseAbstractType() {
3581    if (Invalid) return;
3582    S.DiagnoseAbstractType(Record);
3583    Invalid = true;
3584  }
3585
3586  void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
3587};
3588
3589struct CheckAbstractUsage {
3590  AbstractUsageInfo &Info;
3591  const NamedDecl *Ctx;
3592
3593  CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
3594    : Info(Info), Ctx(Ctx) {}
3595
3596  void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
3597    switch (TL.getTypeLocClass()) {
3598#define ABSTRACT_TYPELOC(CLASS, PARENT)
3599#define TYPELOC(CLASS, PARENT) \
3600    case TypeLoc::CLASS: Check(cast<CLASS##TypeLoc>(TL), Sel); break;
3601#include "clang/AST/TypeLocNodes.def"
3602    }
3603  }
3604
3605  void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
3606    Visit(TL.getResultLoc(), Sema::AbstractReturnType);
3607    for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
3608      if (!TL.getArg(I))
3609        continue;
3610
3611      TypeSourceInfo *TSI = TL.getArg(I)->getTypeSourceInfo();
3612      if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
3613    }
3614  }
3615
3616  void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
3617    Visit(TL.getElementLoc(), Sema::AbstractArrayType);
3618  }
3619
3620  void Check(TemplateSpecializationTypeLoc TL, Sema::AbstractDiagSelID Sel) {
3621    // Visit the type parameters from a permissive context.
3622    for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
3623      TemplateArgumentLoc TAL = TL.getArgLoc(I);
3624      if (TAL.getArgument().getKind() == TemplateArgument::Type)
3625        if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
3626          Visit(TSI->getTypeLoc(), Sema::AbstractNone);
3627      // TODO: other template argument types?
3628    }
3629  }
3630
3631  // Visit pointee types from a permissive context.
3632#define CheckPolymorphic(Type) \
3633  void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
3634    Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
3635  }
3636  CheckPolymorphic(PointerTypeLoc)
3637  CheckPolymorphic(ReferenceTypeLoc)
3638  CheckPolymorphic(MemberPointerTypeLoc)
3639  CheckPolymorphic(BlockPointerTypeLoc)
3640  CheckPolymorphic(AtomicTypeLoc)
3641
3642  /// Handle all the types we haven't given a more specific
3643  /// implementation for above.
3644  void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
3645    // Every other kind of type that we haven't called out already
3646    // that has an inner type is either (1) sugar or (2) contains that
3647    // inner type in some way as a subobject.
3648    if (TypeLoc Next = TL.getNextTypeLoc())
3649      return Visit(Next, Sel);
3650
3651    // If there's no inner type and we're in a permissive context,
3652    // don't diagnose.
3653    if (Sel == Sema::AbstractNone) return;
3654
3655    // Check whether the type matches the abstract type.
3656    QualType T = TL.getType();
3657    if (T->isArrayType()) {
3658      Sel = Sema::AbstractArrayType;
3659      T = Info.S.Context.getBaseElementType(T);
3660    }
3661    CanQualType CT = T->getCanonicalTypeUnqualified().getUnqualifiedType();
3662    if (CT != Info.AbstractType) return;
3663
3664    // It matched; do some magic.
3665    if (Sel == Sema::AbstractArrayType) {
3666      Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
3667        << T << TL.getSourceRange();
3668    } else {
3669      Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
3670        << Sel << T << TL.getSourceRange();
3671    }
3672    Info.DiagnoseAbstractType();
3673  }
3674};
3675
3676void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
3677                                  Sema::AbstractDiagSelID Sel) {
3678  CheckAbstractUsage(*this, D).Visit(TL, Sel);
3679}
3680
3681}
3682
3683/// Check for invalid uses of an abstract type in a method declaration.
3684static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
3685                                    CXXMethodDecl *MD) {
3686  // No need to do the check on definitions, which require that
3687  // the return/param types be complete.
3688  if (MD->doesThisDeclarationHaveABody())
3689    return;
3690
3691  // For safety's sake, just ignore it if we don't have type source
3692  // information.  This should never happen for non-implicit methods,
3693  // but...
3694  if (TypeSourceInfo *TSI = MD->getTypeSourceInfo())
3695    Info.CheckType(MD, TSI->getTypeLoc(), Sema::AbstractNone);
3696}
3697
3698/// Check for invalid uses of an abstract type within a class definition.
3699static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
3700                                    CXXRecordDecl *RD) {
3701  for (CXXRecordDecl::decl_iterator
3702         I = RD->decls_begin(), E = RD->decls_end(); I != E; ++I) {
3703    Decl *D = *I;
3704    if (D->isImplicit()) continue;
3705
3706    // Methods and method templates.
3707    if (isa<CXXMethodDecl>(D)) {
3708      CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(D));
3709    } else if (isa<FunctionTemplateDecl>(D)) {
3710      FunctionDecl *FD = cast<FunctionTemplateDecl>(D)->getTemplatedDecl();
3711      CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(FD));
3712
3713    // Fields and static variables.
3714    } else if (isa<FieldDecl>(D)) {
3715      FieldDecl *FD = cast<FieldDecl>(D);
3716      if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
3717        Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
3718    } else if (isa<VarDecl>(D)) {
3719      VarDecl *VD = cast<VarDecl>(D);
3720      if (TypeSourceInfo *TSI = VD->getTypeSourceInfo())
3721        Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType);
3722
3723    // Nested classes and class templates.
3724    } else if (isa<CXXRecordDecl>(D)) {
3725      CheckAbstractClassUsage(Info, cast<CXXRecordDecl>(D));
3726    } else if (isa<ClassTemplateDecl>(D)) {
3727      CheckAbstractClassUsage(Info,
3728                             cast<ClassTemplateDecl>(D)->getTemplatedDecl());
3729    }
3730  }
3731}
3732
3733/// \brief Perform semantic checks on a class definition that has been
3734/// completing, introducing implicitly-declared members, checking for
3735/// abstract types, etc.
3736void Sema::CheckCompletedCXXClass(CXXRecordDecl *Record) {
3737  if (!Record)
3738    return;
3739
3740  if (Record->isAbstract() && !Record->isInvalidDecl()) {
3741    AbstractUsageInfo Info(*this, Record);
3742    CheckAbstractClassUsage(Info, Record);
3743  }
3744
3745  // If this is not an aggregate type and has no user-declared constructor,
3746  // complain about any non-static data members of reference or const scalar
3747  // type, since they will never get initializers.
3748  if (!Record->isInvalidDecl() && !Record->isDependentType() &&
3749      !Record->isAggregate() && !Record->hasUserDeclaredConstructor() &&
3750      !Record->isLambda()) {
3751    bool Complained = false;
3752    for (RecordDecl::field_iterator F = Record->field_begin(),
3753                                 FEnd = Record->field_end();
3754         F != FEnd; ++F) {
3755      if (F->hasInClassInitializer() || F->isUnnamedBitfield())
3756        continue;
3757
3758      if (F->getType()->isReferenceType() ||
3759          (F->getType().isConstQualified() && F->getType()->isScalarType())) {
3760        if (!Complained) {
3761          Diag(Record->getLocation(), diag::warn_no_constructor_for_refconst)
3762            << Record->getTagKind() << Record;
3763          Complained = true;
3764        }
3765
3766        Diag(F->getLocation(), diag::note_refconst_member_not_initialized)
3767          << F->getType()->isReferenceType()
3768          << F->getDeclName();
3769      }
3770    }
3771  }
3772
3773  if (Record->isDynamicClass() && !Record->isDependentType())
3774    DynamicClasses.push_back(Record);
3775
3776  if (Record->getIdentifier()) {
3777    // C++ [class.mem]p13:
3778    //   If T is the name of a class, then each of the following shall have a
3779    //   name different from T:
3780    //     - every member of every anonymous union that is a member of class T.
3781    //
3782    // C++ [class.mem]p14:
3783    //   In addition, if class T has a user-declared constructor (12.1), every
3784    //   non-static data member of class T shall have a name different from T.
3785    for (DeclContext::lookup_result R = Record->lookup(Record->getDeclName());
3786         R.first != R.second; ++R.first) {
3787      NamedDecl *D = *R.first;
3788      if ((isa<FieldDecl>(D) && Record->hasUserDeclaredConstructor()) ||
3789          isa<IndirectFieldDecl>(D)) {
3790        Diag(D->getLocation(), diag::err_member_name_of_class)
3791          << D->getDeclName();
3792        break;
3793      }
3794    }
3795  }
3796
3797  // Warn if the class has virtual methods but non-virtual public destructor.
3798  if (Record->isPolymorphic() && !Record->isDependentType()) {
3799    CXXDestructorDecl *dtor = Record->getDestructor();
3800    if (!dtor || (!dtor->isVirtual() && dtor->getAccess() == AS_public))
3801      Diag(dtor ? dtor->getLocation() : Record->getLocation(),
3802           diag::warn_non_virtual_dtor) << Context.getRecordType(Record);
3803  }
3804
3805  // See if a method overloads virtual methods in a base
3806  /// class without overriding any.
3807  if (!Record->isDependentType()) {
3808    for (CXXRecordDecl::method_iterator M = Record->method_begin(),
3809                                     MEnd = Record->method_end();
3810         M != MEnd; ++M) {
3811      if (!M->isStatic())
3812        DiagnoseHiddenVirtualMethods(Record, *M);
3813    }
3814  }
3815
3816  // C++0x [dcl.constexpr]p8: A constexpr specifier for a non-static member
3817  // function that is not a constructor declares that member function to be
3818  // const. [...] The class of which that function is a member shall be
3819  // a literal type.
3820  //
3821  // If the class has virtual bases, any constexpr members will already have
3822  // been diagnosed by the checks performed on the member declaration, so
3823  // suppress this (less useful) diagnostic.
3824  if (LangOpts.CPlusPlus0x && !Record->isDependentType() &&
3825      !Record->isLiteral() && !Record->getNumVBases()) {
3826    for (CXXRecordDecl::method_iterator M = Record->method_begin(),
3827                                     MEnd = Record->method_end();
3828         M != MEnd; ++M) {
3829      if (M->isConstexpr() && M->isInstance() && !isa<CXXConstructorDecl>(*M)) {
3830        switch (Record->getTemplateSpecializationKind()) {
3831        case TSK_ImplicitInstantiation:
3832        case TSK_ExplicitInstantiationDeclaration:
3833        case TSK_ExplicitInstantiationDefinition:
3834          // If a template instantiates to a non-literal type, but its members
3835          // instantiate to constexpr functions, the template is technically
3836          // ill-formed, but we allow it for sanity.
3837          continue;
3838
3839        case TSK_Undeclared:
3840        case TSK_ExplicitSpecialization:
3841          RequireLiteralType(M->getLocation(), Context.getRecordType(Record),
3842                             diag::err_constexpr_method_non_literal);
3843          break;
3844        }
3845
3846        // Only produce one error per class.
3847        break;
3848      }
3849    }
3850  }
3851
3852  // Declare inherited constructors. We do this eagerly here because:
3853  // - The standard requires an eager diagnostic for conflicting inherited
3854  //   constructors from different classes.
3855  // - The lazy declaration of the other implicit constructors is so as to not
3856  //   waste space and performance on classes that are not meant to be
3857  //   instantiated (e.g. meta-functions). This doesn't apply to classes that
3858  //   have inherited constructors.
3859  DeclareInheritedConstructors(Record);
3860
3861  if (!Record->isDependentType())
3862    CheckExplicitlyDefaultedMethods(Record);
3863}
3864
3865void Sema::CheckExplicitlyDefaultedMethods(CXXRecordDecl *Record) {
3866  for (CXXRecordDecl::method_iterator MI = Record->method_begin(),
3867                                      ME = Record->method_end();
3868       MI != ME; ++MI)
3869    if (!MI->isInvalidDecl() && MI->isExplicitlyDefaulted())
3870      CheckExplicitlyDefaultedSpecialMember(*MI);
3871}
3872
3873/// Is the special member function which would be selected to perform the
3874/// specified operation on the specified class type a constexpr constructor?
3875static bool specialMemberIsConstexpr(Sema &S, CXXRecordDecl *ClassDecl,
3876                                     Sema::CXXSpecialMember CSM,
3877                                     bool ConstArg) {
3878  Sema::SpecialMemberOverloadResult *SMOR =
3879      S.LookupSpecialMember(ClassDecl, CSM, ConstArg,
3880                            false, false, false, false);
3881  if (!SMOR || !SMOR->getMethod())
3882    // A constructor we wouldn't select can't be "involved in initializing"
3883    // anything.
3884    return true;
3885  return SMOR->getMethod()->isConstexpr();
3886}
3887
3888/// Determine whether the specified special member function would be constexpr
3889/// if it were implicitly defined.
3890static bool defaultedSpecialMemberIsConstexpr(Sema &S, CXXRecordDecl *ClassDecl,
3891                                              Sema::CXXSpecialMember CSM,
3892                                              bool ConstArg) {
3893  if (!S.getLangOpts().CPlusPlus0x)
3894    return false;
3895
3896  // C++11 [dcl.constexpr]p4:
3897  // In the definition of a constexpr constructor [...]
3898  switch (CSM) {
3899  case Sema::CXXDefaultConstructor:
3900    // Since default constructor lookup is essentially trivial (and cannot
3901    // involve, for instance, template instantiation), we compute whether a
3902    // defaulted default constructor is constexpr directly within CXXRecordDecl.
3903    //
3904    // This is important for performance; we need to know whether the default
3905    // constructor is constexpr to determine whether the type is a literal type.
3906    return ClassDecl->defaultedDefaultConstructorIsConstexpr();
3907
3908  case Sema::CXXCopyConstructor:
3909  case Sema::CXXMoveConstructor:
3910    // For copy or move constructors, we need to perform overload resolution.
3911    break;
3912
3913  case Sema::CXXCopyAssignment:
3914  case Sema::CXXMoveAssignment:
3915  case Sema::CXXDestructor:
3916  case Sema::CXXInvalid:
3917    return false;
3918  }
3919
3920  //   -- if the class is a non-empty union, or for each non-empty anonymous
3921  //      union member of a non-union class, exactly one non-static data member
3922  //      shall be initialized; [DR1359]
3923  //
3924  // If we squint, this is guaranteed, since exactly one non-static data member
3925  // will be initialized (if the constructor isn't deleted), we just don't know
3926  // which one.
3927  if (ClassDecl->isUnion())
3928    return true;
3929
3930  //   -- the class shall not have any virtual base classes;
3931  if (ClassDecl->getNumVBases())
3932    return false;
3933
3934  //   -- every constructor involved in initializing [...] base class
3935  //      sub-objects shall be a constexpr constructor;
3936  for (CXXRecordDecl::base_class_iterator B = ClassDecl->bases_begin(),
3937                                       BEnd = ClassDecl->bases_end();
3938       B != BEnd; ++B) {
3939    const RecordType *BaseType = B->getType()->getAs<RecordType>();
3940    if (!BaseType) continue;
3941
3942    CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
3943    if (!specialMemberIsConstexpr(S, BaseClassDecl, CSM, ConstArg))
3944      return false;
3945  }
3946
3947  //   -- every constructor involved in initializing non-static data members
3948  //      [...] shall be a constexpr constructor;
3949  //   -- every non-static data member and base class sub-object shall be
3950  //      initialized
3951  for (RecordDecl::field_iterator F = ClassDecl->field_begin(),
3952                               FEnd = ClassDecl->field_end();
3953       F != FEnd; ++F) {
3954    if (F->isInvalidDecl())
3955      continue;
3956    if (const RecordType *RecordTy =
3957            S.Context.getBaseElementType(F->getType())->getAs<RecordType>()) {
3958      CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
3959      if (!specialMemberIsConstexpr(S, FieldRecDecl, CSM, ConstArg))
3960        return false;
3961    }
3962  }
3963
3964  // All OK, it's constexpr!
3965  return true;
3966}
3967
3968void Sema::CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD) {
3969  CXXRecordDecl *RD = MD->getParent();
3970  CXXSpecialMember CSM = getSpecialMember(MD);
3971
3972  assert(MD->isExplicitlyDefaulted() && CSM != CXXInvalid &&
3973         "not an explicitly-defaulted special member");
3974
3975  // Whether this was the first-declared instance of the constructor.
3976  // This affects whether we implicitly add an exception spec and constexpr.
3977  bool First = MD == MD->getCanonicalDecl();
3978
3979  bool HadError = false;
3980
3981  // C++11 [dcl.fct.def.default]p1:
3982  //   A function that is explicitly defaulted shall
3983  //     -- be a special member function (checked elsewhere),
3984  //     -- have the same type (except for ref-qualifiers, and except that a
3985  //        copy operation can take a non-const reference) as an implicit
3986  //        declaration, and
3987  //     -- not have default arguments.
3988  unsigned ExpectedParams = 1;
3989  if (CSM == CXXDefaultConstructor || CSM == CXXDestructor)
3990    ExpectedParams = 0;
3991  if (MD->getNumParams() != ExpectedParams) {
3992    // This also checks for default arguments: a copy or move constructor with a
3993    // default argument is classified as a default constructor, and assignment
3994    // operations and destructors can't have default arguments.
3995    Diag(MD->getLocation(), diag::err_defaulted_special_member_params)
3996      << CSM << MD->getSourceRange();
3997    HadError = true;
3998  }
3999
4000  const FunctionProtoType *Type = MD->getType()->getAs<FunctionProtoType>();
4001
4002  // Compute implicit exception specification, argument constness, constexpr
4003  // and triviality.
4004  ImplicitExceptionSpecification Spec(*this);
4005  bool CanHaveConstParam = false;
4006  bool Trivial;
4007  switch (CSM) {
4008  case CXXDefaultConstructor:
4009    Spec = ComputeDefaultedDefaultCtorExceptionSpec(RD);
4010    if (Spec.isDelayed())
4011      // Exception specification depends on some deferred part of the class.
4012      // We'll try again when the class's definition has been fully processed.
4013      return;
4014    Trivial = RD->hasTrivialDefaultConstructor();
4015    break;
4016  case CXXCopyConstructor:
4017    llvm::tie(Spec, CanHaveConstParam) =
4018      ComputeDefaultedCopyCtorExceptionSpecAndConst(RD);
4019    Trivial = RD->hasTrivialCopyConstructor();
4020    break;
4021  case CXXCopyAssignment:
4022    llvm::tie(Spec, CanHaveConstParam) =
4023      ComputeDefaultedCopyAssignmentExceptionSpecAndConst(RD);
4024    Trivial = RD->hasTrivialCopyAssignment();
4025    break;
4026  case CXXMoveConstructor:
4027    Spec = ComputeDefaultedMoveCtorExceptionSpec(RD);
4028    Trivial = RD->hasTrivialMoveConstructor();
4029    break;
4030  case CXXMoveAssignment:
4031    Spec = ComputeDefaultedMoveAssignmentExceptionSpec(RD);
4032    Trivial = RD->hasTrivialMoveAssignment();
4033    break;
4034  case CXXDestructor:
4035    Spec = ComputeDefaultedDtorExceptionSpec(RD);
4036    Trivial = RD->hasTrivialDestructor();
4037    break;
4038  case CXXInvalid:
4039    llvm_unreachable("non-special member explicitly defaulted!");
4040  }
4041
4042  QualType ReturnType = Context.VoidTy;
4043  if (CSM == CXXCopyAssignment || CSM == CXXMoveAssignment) {
4044    // Check for return type matching.
4045    ReturnType = Type->getResultType();
4046    QualType ExpectedReturnType =
4047        Context.getLValueReferenceType(Context.getTypeDeclType(RD));
4048    if (!Context.hasSameType(ReturnType, ExpectedReturnType)) {
4049      Diag(MD->getLocation(), diag::err_defaulted_special_member_return_type)
4050        << (CSM == CXXMoveAssignment) << ExpectedReturnType;
4051      HadError = true;
4052    }
4053
4054    // A defaulted special member cannot have cv-qualifiers.
4055    if (Type->getTypeQuals()) {
4056      Diag(MD->getLocation(), diag::err_defaulted_special_member_quals)
4057        << (CSM == CXXMoveAssignment);
4058      HadError = true;
4059    }
4060  }
4061
4062  // Check for parameter type matching.
4063  QualType ArgType = ExpectedParams ? Type->getArgType(0) : QualType();
4064  bool HasConstParam = false;
4065  if (ExpectedParams && ArgType->isReferenceType()) {
4066    // Argument must be reference to possibly-const T.
4067    QualType ReferentType = ArgType->getPointeeType();
4068    HasConstParam = ReferentType.isConstQualified();
4069
4070    if (ReferentType.isVolatileQualified()) {
4071      Diag(MD->getLocation(),
4072           diag::err_defaulted_special_member_volatile_param) << CSM;
4073      HadError = true;
4074    }
4075
4076    if (HasConstParam && !CanHaveConstParam) {
4077      if (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment) {
4078        Diag(MD->getLocation(),
4079             diag::err_defaulted_special_member_copy_const_param)
4080          << (CSM == CXXCopyAssignment);
4081        // FIXME: Explain why this special member can't be const.
4082      } else {
4083        Diag(MD->getLocation(),
4084             diag::err_defaulted_special_member_move_const_param)
4085          << (CSM == CXXMoveAssignment);
4086      }
4087      HadError = true;
4088    }
4089
4090    // If a function is explicitly defaulted on its first declaration, it shall
4091    // have the same parameter type as if it had been implicitly declared.
4092    // (Presumably this is to prevent it from being trivial?)
4093    if (!HasConstParam && CanHaveConstParam && First)
4094      Diag(MD->getLocation(),
4095           diag::err_defaulted_special_member_copy_non_const_param)
4096        << (CSM == CXXCopyAssignment);
4097  } else if (ExpectedParams) {
4098    // A copy assignment operator can take its argument by value, but a
4099    // defaulted one cannot.
4100    assert(CSM == CXXCopyAssignment && "unexpected non-ref argument");
4101    Diag(MD->getLocation(), diag::err_defaulted_copy_assign_not_ref);
4102    HadError = true;
4103  }
4104
4105  // Rebuild the type with the implicit exception specification added.
4106  FunctionProtoType::ExtProtoInfo EPI = Type->getExtProtoInfo();
4107  Spec.getEPI(EPI);
4108  const FunctionProtoType *ImplicitType = cast<FunctionProtoType>(
4109    Context.getFunctionType(ReturnType, &ArgType, ExpectedParams, EPI));
4110
4111  // C++11 [dcl.fct.def.default]p2:
4112  //   An explicitly-defaulted function may be declared constexpr only if it
4113  //   would have been implicitly declared as constexpr,
4114  // Do not apply this rule to members of class templates, since core issue 1358
4115  // makes such functions always instantiate to constexpr functions. For
4116  // non-constructors, this is checked elsewhere.
4117  bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, RD, CSM,
4118                                                     HasConstParam);
4119  if (isa<CXXConstructorDecl>(MD) && MD->isConstexpr() && !Constexpr &&
4120      MD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) {
4121    Diag(MD->getLocStart(), diag::err_incorrect_defaulted_constexpr) << CSM;
4122    // FIXME: Explain why the constructor can't be constexpr.
4123    HadError = true;
4124  }
4125  //   and may have an explicit exception-specification only if it is compatible
4126  //   with the exception-specification on the implicit declaration.
4127  if (Type->hasExceptionSpec() &&
4128      CheckEquivalentExceptionSpec(
4129        PDiag(diag::err_incorrect_defaulted_exception_spec) << CSM,
4130        PDiag(), ImplicitType, SourceLocation(), Type, MD->getLocation()))
4131    HadError = true;
4132
4133  //   If a function is explicitly defaulted on its first declaration,
4134  if (First) {
4135    //  -- it is implicitly considered to be constexpr if the implicit
4136    //     definition would be,
4137    MD->setConstexpr(Constexpr);
4138
4139    //  -- it is implicitly considered to have the same exception-specification
4140    //     as if it had been implicitly declared,
4141    MD->setType(QualType(ImplicitType, 0));
4142
4143    // Such a function is also trivial if the implicitly-declared function
4144    // would have been.
4145    MD->setTrivial(Trivial);
4146  }
4147
4148  if (ShouldDeleteSpecialMember(MD, CSM)) {
4149    if (First) {
4150      MD->setDeletedAsWritten();
4151    } else {
4152      // C++11 [dcl.fct.def.default]p4:
4153      //   [For a] user-provided explicitly-defaulted function [...] if such a
4154      //   function is implicitly defined as deleted, the program is ill-formed.
4155      Diag(MD->getLocation(), diag::err_out_of_line_default_deletes) << CSM;
4156      HadError = true;
4157    }
4158  }
4159
4160  if (HadError)
4161    MD->setInvalidDecl();
4162}
4163
4164namespace {
4165struct SpecialMemberDeletionInfo {
4166  Sema &S;
4167  CXXMethodDecl *MD;
4168  Sema::CXXSpecialMember CSM;
4169  bool Diagnose;
4170
4171  // Properties of the special member, computed for convenience.
4172  bool IsConstructor, IsAssignment, IsMove, ConstArg, VolatileArg;
4173  SourceLocation Loc;
4174
4175  bool AllFieldsAreConst;
4176
4177  SpecialMemberDeletionInfo(Sema &S, CXXMethodDecl *MD,
4178                            Sema::CXXSpecialMember CSM, bool Diagnose)
4179    : S(S), MD(MD), CSM(CSM), Diagnose(Diagnose),
4180      IsConstructor(false), IsAssignment(false), IsMove(false),
4181      ConstArg(false), VolatileArg(false), Loc(MD->getLocation()),
4182      AllFieldsAreConst(true) {
4183    switch (CSM) {
4184      case Sema::CXXDefaultConstructor:
4185      case Sema::CXXCopyConstructor:
4186        IsConstructor = true;
4187        break;
4188      case Sema::CXXMoveConstructor:
4189        IsConstructor = true;
4190        IsMove = true;
4191        break;
4192      case Sema::CXXCopyAssignment:
4193        IsAssignment = true;
4194        break;
4195      case Sema::CXXMoveAssignment:
4196        IsAssignment = true;
4197        IsMove = true;
4198        break;
4199      case Sema::CXXDestructor:
4200        break;
4201      case Sema::CXXInvalid:
4202        llvm_unreachable("invalid special member kind");
4203    }
4204
4205    if (MD->getNumParams()) {
4206      ConstArg = MD->getParamDecl(0)->getType().isConstQualified();
4207      VolatileArg = MD->getParamDecl(0)->getType().isVolatileQualified();
4208    }
4209  }
4210
4211  bool inUnion() const { return MD->getParent()->isUnion(); }
4212
4213  /// Look up the corresponding special member in the given class.
4214  Sema::SpecialMemberOverloadResult *lookupIn(CXXRecordDecl *Class) {
4215    unsigned TQ = MD->getTypeQualifiers();
4216    return S.LookupSpecialMember(Class, CSM, ConstArg, VolatileArg,
4217                                 MD->getRefQualifier() == RQ_RValue,
4218                                 TQ & Qualifiers::Const,
4219                                 TQ & Qualifiers::Volatile);
4220  }
4221
4222  typedef llvm::PointerUnion<CXXBaseSpecifier*, FieldDecl*> Subobject;
4223
4224  bool shouldDeleteForBase(CXXBaseSpecifier *Base);
4225  bool shouldDeleteForField(FieldDecl *FD);
4226  bool shouldDeleteForAllConstMembers();
4227
4228  bool shouldDeleteForClassSubobject(CXXRecordDecl *Class, Subobject Subobj);
4229  bool shouldDeleteForSubobjectCall(Subobject Subobj,
4230                                    Sema::SpecialMemberOverloadResult *SMOR,
4231                                    bool IsDtorCallInCtor);
4232
4233  bool isAccessible(Subobject Subobj, CXXMethodDecl *D);
4234};
4235}
4236
4237/// Is the given special member inaccessible when used on the given
4238/// sub-object.
4239bool SpecialMemberDeletionInfo::isAccessible(Subobject Subobj,
4240                                             CXXMethodDecl *target) {
4241  /// If we're operating on a base class, the object type is the
4242  /// type of this special member.
4243  QualType objectTy;
4244  AccessSpecifier access = target->getAccess();;
4245  if (CXXBaseSpecifier *base = Subobj.dyn_cast<CXXBaseSpecifier*>()) {
4246    objectTy = S.Context.getTypeDeclType(MD->getParent());
4247    access = CXXRecordDecl::MergeAccess(base->getAccessSpecifier(), access);
4248
4249  // If we're operating on a field, the object type is the type of the field.
4250  } else {
4251    objectTy = S.Context.getTypeDeclType(target->getParent());
4252  }
4253
4254  return S.isSpecialMemberAccessibleForDeletion(target, access, objectTy);
4255}
4256
4257/// Check whether we should delete a special member due to the implicit
4258/// definition containing a call to a special member of a subobject.
4259bool SpecialMemberDeletionInfo::shouldDeleteForSubobjectCall(
4260    Subobject Subobj, Sema::SpecialMemberOverloadResult *SMOR,
4261    bool IsDtorCallInCtor) {
4262  CXXMethodDecl *Decl = SMOR->getMethod();
4263  FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
4264
4265  int DiagKind = -1;
4266
4267  if (SMOR->getKind() == Sema::SpecialMemberOverloadResult::NoMemberOrDeleted)
4268    DiagKind = !Decl ? 0 : 1;
4269  else if (SMOR->getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
4270    DiagKind = 2;
4271  else if (!isAccessible(Subobj, Decl))
4272    DiagKind = 3;
4273  else if (!IsDtorCallInCtor && Field && Field->getParent()->isUnion() &&
4274           !Decl->isTrivial()) {
4275    // A member of a union must have a trivial corresponding special member.
4276    // As a weird special case, a destructor call from a union's constructor
4277    // must be accessible and non-deleted, but need not be trivial. Such a
4278    // destructor is never actually called, but is semantically checked as
4279    // if it were.
4280    DiagKind = 4;
4281  }
4282
4283  if (DiagKind == -1)
4284    return false;
4285
4286  if (Diagnose) {
4287    if (Field) {
4288      S.Diag(Field->getLocation(),
4289             diag::note_deleted_special_member_class_subobject)
4290        << CSM << MD->getParent() << /*IsField*/true
4291        << Field << DiagKind << IsDtorCallInCtor;
4292    } else {
4293      CXXBaseSpecifier *Base = Subobj.get<CXXBaseSpecifier*>();
4294      S.Diag(Base->getLocStart(),
4295             diag::note_deleted_special_member_class_subobject)
4296        << CSM << MD->getParent() << /*IsField*/false
4297        << Base->getType() << DiagKind << IsDtorCallInCtor;
4298    }
4299
4300    if (DiagKind == 1)
4301      S.NoteDeletedFunction(Decl);
4302    // FIXME: Explain inaccessibility if DiagKind == 3.
4303  }
4304
4305  return true;
4306}
4307
4308/// Check whether we should delete a special member function due to having a
4309/// direct or virtual base class or static data member of class type M.
4310bool SpecialMemberDeletionInfo::shouldDeleteForClassSubobject(
4311    CXXRecordDecl *Class, Subobject Subobj) {
4312  FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
4313
4314  // C++11 [class.ctor]p5:
4315  // -- any direct or virtual base class, or non-static data member with no
4316  //    brace-or-equal-initializer, has class type M (or array thereof) and
4317  //    either M has no default constructor or overload resolution as applied
4318  //    to M's default constructor results in an ambiguity or in a function
4319  //    that is deleted or inaccessible
4320  // C++11 [class.copy]p11, C++11 [class.copy]p23:
4321  // -- a direct or virtual base class B that cannot be copied/moved because
4322  //    overload resolution, as applied to B's corresponding special member,
4323  //    results in an ambiguity or a function that is deleted or inaccessible
4324  //    from the defaulted special member
4325  // C++11 [class.dtor]p5:
4326  // -- any direct or virtual base class [...] has a type with a destructor
4327  //    that is deleted or inaccessible
4328  if (!(CSM == Sema::CXXDefaultConstructor &&
4329        Field && Field->hasInClassInitializer()) &&
4330      shouldDeleteForSubobjectCall(Subobj, lookupIn(Class), false))
4331    return true;
4332
4333  // C++11 [class.ctor]p5, C++11 [class.copy]p11:
4334  // -- any direct or virtual base class or non-static data member has a
4335  //    type with a destructor that is deleted or inaccessible
4336  if (IsConstructor) {
4337    Sema::SpecialMemberOverloadResult *SMOR =
4338        S.LookupSpecialMember(Class, Sema::CXXDestructor,
4339                              false, false, false, false, false);
4340    if (shouldDeleteForSubobjectCall(Subobj, SMOR, true))
4341      return true;
4342  }
4343
4344  return false;
4345}
4346
4347/// Check whether we should delete a special member function due to the class
4348/// having a particular direct or virtual base class.
4349bool SpecialMemberDeletionInfo::shouldDeleteForBase(CXXBaseSpecifier *Base) {
4350  CXXRecordDecl *BaseClass = Base->getType()->getAsCXXRecordDecl();
4351  return shouldDeleteForClassSubobject(BaseClass, Base);
4352}
4353
4354/// Check whether we should delete a special member function due to the class
4355/// having a particular non-static data member.
4356bool SpecialMemberDeletionInfo::shouldDeleteForField(FieldDecl *FD) {
4357  QualType FieldType = S.Context.getBaseElementType(FD->getType());
4358  CXXRecordDecl *FieldRecord = FieldType->getAsCXXRecordDecl();
4359
4360  if (CSM == Sema::CXXDefaultConstructor) {
4361    // For a default constructor, all references must be initialized in-class
4362    // and, if a union, it must have a non-const member.
4363    if (FieldType->isReferenceType() && !FD->hasInClassInitializer()) {
4364      if (Diagnose)
4365        S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
4366          << MD->getParent() << FD << FieldType << /*Reference*/0;
4367      return true;
4368    }
4369    // C++11 [class.ctor]p5: any non-variant non-static data member of
4370    // const-qualified type (or array thereof) with no
4371    // brace-or-equal-initializer does not have a user-provided default
4372    // constructor.
4373    if (!inUnion() && FieldType.isConstQualified() &&
4374        !FD->hasInClassInitializer() &&
4375        (!FieldRecord || !FieldRecord->hasUserProvidedDefaultConstructor())) {
4376      if (Diagnose)
4377        S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
4378          << MD->getParent() << FD << FD->getType() << /*Const*/1;
4379      return true;
4380    }
4381
4382    if (inUnion() && !FieldType.isConstQualified())
4383      AllFieldsAreConst = false;
4384  } else if (CSM == Sema::CXXCopyConstructor) {
4385    // For a copy constructor, data members must not be of rvalue reference
4386    // type.
4387    if (FieldType->isRValueReferenceType()) {
4388      if (Diagnose)
4389        S.Diag(FD->getLocation(), diag::note_deleted_copy_ctor_rvalue_reference)
4390          << MD->getParent() << FD << FieldType;
4391      return true;
4392    }
4393  } else if (IsAssignment) {
4394    // For an assignment operator, data members must not be of reference type.
4395    if (FieldType->isReferenceType()) {
4396      if (Diagnose)
4397        S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
4398          << IsMove << MD->getParent() << FD << FieldType << /*Reference*/0;
4399      return true;
4400    }
4401    if (!FieldRecord && FieldType.isConstQualified()) {
4402      // C++11 [class.copy]p23:
4403      // -- a non-static data member of const non-class type (or array thereof)
4404      if (Diagnose)
4405        S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
4406          << IsMove << MD->getParent() << FD << FD->getType() << /*Const*/1;
4407      return true;
4408    }
4409  }
4410
4411  if (FieldRecord) {
4412    // Some additional restrictions exist on the variant members.
4413    if (!inUnion() && FieldRecord->isUnion() &&
4414        FieldRecord->isAnonymousStructOrUnion()) {
4415      bool AllVariantFieldsAreConst = true;
4416
4417      // FIXME: Handle anonymous unions declared within anonymous unions.
4418      for (CXXRecordDecl::field_iterator UI = FieldRecord->field_begin(),
4419                                         UE = FieldRecord->field_end();
4420           UI != UE; ++UI) {
4421        QualType UnionFieldType = S.Context.getBaseElementType(UI->getType());
4422
4423        if (!UnionFieldType.isConstQualified())
4424          AllVariantFieldsAreConst = false;
4425
4426        CXXRecordDecl *UnionFieldRecord = UnionFieldType->getAsCXXRecordDecl();
4427        if (UnionFieldRecord &&
4428            shouldDeleteForClassSubobject(UnionFieldRecord, *UI))
4429          return true;
4430      }
4431
4432      // At least one member in each anonymous union must be non-const
4433      if (CSM == Sema::CXXDefaultConstructor && AllVariantFieldsAreConst &&
4434          FieldRecord->field_begin() != FieldRecord->field_end()) {
4435        if (Diagnose)
4436          S.Diag(FieldRecord->getLocation(),
4437                 diag::note_deleted_default_ctor_all_const)
4438            << MD->getParent() << /*anonymous union*/1;
4439        return true;
4440      }
4441
4442      // Don't check the implicit member of the anonymous union type.
4443      // This is technically non-conformant, but sanity demands it.
4444      return false;
4445    }
4446
4447    if (shouldDeleteForClassSubobject(FieldRecord, FD))
4448      return true;
4449  }
4450
4451  return false;
4452}
4453
4454/// C++11 [class.ctor] p5:
4455///   A defaulted default constructor for a class X is defined as deleted if
4456/// X is a union and all of its variant members are of const-qualified type.
4457bool SpecialMemberDeletionInfo::shouldDeleteForAllConstMembers() {
4458  // This is a silly definition, because it gives an empty union a deleted
4459  // default constructor. Don't do that.
4460  if (CSM == Sema::CXXDefaultConstructor && inUnion() && AllFieldsAreConst &&
4461      (MD->getParent()->field_begin() != MD->getParent()->field_end())) {
4462    if (Diagnose)
4463      S.Diag(MD->getParent()->getLocation(),
4464             diag::note_deleted_default_ctor_all_const)
4465        << MD->getParent() << /*not anonymous union*/0;
4466    return true;
4467  }
4468  return false;
4469}
4470
4471/// Determine whether a defaulted special member function should be defined as
4472/// deleted, as specified in C++11 [class.ctor]p5, C++11 [class.copy]p11,
4473/// C++11 [class.copy]p23, and C++11 [class.dtor]p5.
4474bool Sema::ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM,
4475                                     bool Diagnose) {
4476  assert(!MD->isInvalidDecl());
4477  CXXRecordDecl *RD = MD->getParent();
4478  assert(!RD->isDependentType() && "do deletion after instantiation");
4479  if (!LangOpts.CPlusPlus0x || RD->isInvalidDecl())
4480    return false;
4481
4482  // C++11 [expr.lambda.prim]p19:
4483  //   The closure type associated with a lambda-expression has a
4484  //   deleted (8.4.3) default constructor and a deleted copy
4485  //   assignment operator.
4486  if (RD->isLambda() &&
4487      (CSM == CXXDefaultConstructor || CSM == CXXCopyAssignment)) {
4488    if (Diagnose)
4489      Diag(RD->getLocation(), diag::note_lambda_decl);
4490    return true;
4491  }
4492
4493  // For an anonymous struct or union, the copy and assignment special members
4494  // will never be used, so skip the check. For an anonymous union declared at
4495  // namespace scope, the constructor and destructor are used.
4496  if (CSM != CXXDefaultConstructor && CSM != CXXDestructor &&
4497      RD->isAnonymousStructOrUnion())
4498    return false;
4499
4500  // C++11 [class.copy]p7, p18:
4501  //   If the class definition declares a move constructor or move assignment
4502  //   operator, an implicitly declared copy constructor or copy assignment
4503  //   operator is defined as deleted.
4504  if (MD->isImplicit() &&
4505      (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment)) {
4506    CXXMethodDecl *UserDeclaredMove = 0;
4507
4508    // In Microsoft mode, a user-declared move only causes the deletion of the
4509    // corresponding copy operation, not both copy operations.
4510    if (RD->hasUserDeclaredMoveConstructor() &&
4511        (!getLangOpts().MicrosoftMode || CSM == CXXCopyConstructor)) {
4512      if (!Diagnose) return true;
4513      UserDeclaredMove = RD->getMoveConstructor();
4514      assert(UserDeclaredMove);
4515    } else if (RD->hasUserDeclaredMoveAssignment() &&
4516               (!getLangOpts().MicrosoftMode || CSM == CXXCopyAssignment)) {
4517      if (!Diagnose) return true;
4518      UserDeclaredMove = RD->getMoveAssignmentOperator();
4519      assert(UserDeclaredMove);
4520    }
4521
4522    if (UserDeclaredMove) {
4523      Diag(UserDeclaredMove->getLocation(),
4524           diag::note_deleted_copy_user_declared_move)
4525        << (CSM == CXXCopyAssignment) << RD
4526        << UserDeclaredMove->isMoveAssignmentOperator();
4527      return true;
4528    }
4529  }
4530
4531  // Do access control from the special member function
4532  ContextRAII MethodContext(*this, MD);
4533
4534  // C++11 [class.dtor]p5:
4535  // -- for a virtual destructor, lookup of the non-array deallocation function
4536  //    results in an ambiguity or in a function that is deleted or inaccessible
4537  if (CSM == CXXDestructor && MD->isVirtual()) {
4538    FunctionDecl *OperatorDelete = 0;
4539    DeclarationName Name =
4540      Context.DeclarationNames.getCXXOperatorName(OO_Delete);
4541    if (FindDeallocationFunction(MD->getLocation(), MD->getParent(), Name,
4542                                 OperatorDelete, false)) {
4543      if (Diagnose)
4544        Diag(RD->getLocation(), diag::note_deleted_dtor_no_operator_delete);
4545      return true;
4546    }
4547  }
4548
4549  SpecialMemberDeletionInfo SMI(*this, MD, CSM, Diagnose);
4550
4551  for (CXXRecordDecl::base_class_iterator BI = RD->bases_begin(),
4552                                          BE = RD->bases_end(); BI != BE; ++BI)
4553    if (!BI->isVirtual() &&
4554        SMI.shouldDeleteForBase(BI))
4555      return true;
4556
4557  for (CXXRecordDecl::base_class_iterator BI = RD->vbases_begin(),
4558                                          BE = RD->vbases_end(); BI != BE; ++BI)
4559    if (SMI.shouldDeleteForBase(BI))
4560      return true;
4561
4562  for (CXXRecordDecl::field_iterator FI = RD->field_begin(),
4563                                     FE = RD->field_end(); FI != FE; ++FI)
4564    if (!FI->isInvalidDecl() && !FI->isUnnamedBitfield() &&
4565        SMI.shouldDeleteForField(*FI))
4566      return true;
4567
4568  if (SMI.shouldDeleteForAllConstMembers())
4569    return true;
4570
4571  return false;
4572}
4573
4574/// \brief Data used with FindHiddenVirtualMethod
4575namespace {
4576  struct FindHiddenVirtualMethodData {
4577    Sema *S;
4578    CXXMethodDecl *Method;
4579    llvm::SmallPtrSet<const CXXMethodDecl *, 8> OverridenAndUsingBaseMethods;
4580    SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
4581  };
4582}
4583
4584/// \brief Member lookup function that determines whether a given C++
4585/// method overloads virtual methods in a base class without overriding any,
4586/// to be used with CXXRecordDecl::lookupInBases().
4587static bool FindHiddenVirtualMethod(const CXXBaseSpecifier *Specifier,
4588                                    CXXBasePath &Path,
4589                                    void *UserData) {
4590  RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl();
4591
4592  FindHiddenVirtualMethodData &Data
4593    = *static_cast<FindHiddenVirtualMethodData*>(UserData);
4594
4595  DeclarationName Name = Data.Method->getDeclName();
4596  assert(Name.getNameKind() == DeclarationName::Identifier);
4597
4598  bool foundSameNameMethod = false;
4599  SmallVector<CXXMethodDecl *, 8> overloadedMethods;
4600  for (Path.Decls = BaseRecord->lookup(Name);
4601       Path.Decls.first != Path.Decls.second;
4602       ++Path.Decls.first) {
4603    NamedDecl *D = *Path.Decls.first;
4604    if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
4605      MD = MD->getCanonicalDecl();
4606      foundSameNameMethod = true;
4607      // Interested only in hidden virtual methods.
4608      if (!MD->isVirtual())
4609        continue;
4610      // If the method we are checking overrides a method from its base
4611      // don't warn about the other overloaded methods.
4612      if (!Data.S->IsOverload(Data.Method, MD, false))
4613        return true;
4614      // Collect the overload only if its hidden.
4615      if (!Data.OverridenAndUsingBaseMethods.count(MD))
4616        overloadedMethods.push_back(MD);
4617    }
4618  }
4619
4620  if (foundSameNameMethod)
4621    Data.OverloadedMethods.append(overloadedMethods.begin(),
4622                                   overloadedMethods.end());
4623  return foundSameNameMethod;
4624}
4625
4626/// \brief See if a method overloads virtual methods in a base class without
4627/// overriding any.
4628void Sema::DiagnoseHiddenVirtualMethods(CXXRecordDecl *DC, CXXMethodDecl *MD) {
4629  if (Diags.getDiagnosticLevel(diag::warn_overloaded_virtual,
4630                               MD->getLocation()) == DiagnosticsEngine::Ignored)
4631    return;
4632  if (!MD->getDeclName().isIdentifier())
4633    return;
4634
4635  CXXBasePaths Paths(/*FindAmbiguities=*/true, // true to look in all bases.
4636                     /*bool RecordPaths=*/false,
4637                     /*bool DetectVirtual=*/false);
4638  FindHiddenVirtualMethodData Data;
4639  Data.Method = MD;
4640  Data.S = this;
4641
4642  // Keep the base methods that were overriden or introduced in the subclass
4643  // by 'using' in a set. A base method not in this set is hidden.
4644  for (DeclContext::lookup_result res = DC->lookup(MD->getDeclName());
4645       res.first != res.second; ++res.first) {
4646    if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(*res.first))
4647      for (CXXMethodDecl::method_iterator I = MD->begin_overridden_methods(),
4648                                          E = MD->end_overridden_methods();
4649           I != E; ++I)
4650        Data.OverridenAndUsingBaseMethods.insert((*I)->getCanonicalDecl());
4651    if (UsingShadowDecl *shad = dyn_cast<UsingShadowDecl>(*res.first))
4652      if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(shad->getTargetDecl()))
4653        Data.OverridenAndUsingBaseMethods.insert(MD->getCanonicalDecl());
4654  }
4655
4656  if (DC->lookupInBases(&FindHiddenVirtualMethod, &Data, Paths) &&
4657      !Data.OverloadedMethods.empty()) {
4658    Diag(MD->getLocation(), diag::warn_overloaded_virtual)
4659      << MD << (Data.OverloadedMethods.size() > 1);
4660
4661    for (unsigned i = 0, e = Data.OverloadedMethods.size(); i != e; ++i) {
4662      CXXMethodDecl *overloadedMD = Data.OverloadedMethods[i];
4663      Diag(overloadedMD->getLocation(),
4664           diag::note_hidden_overloaded_virtual_declared_here) << overloadedMD;
4665    }
4666  }
4667}
4668
4669void Sema::ActOnFinishCXXMemberSpecification(Scope* S, SourceLocation RLoc,
4670                                             Decl *TagDecl,
4671                                             SourceLocation LBrac,
4672                                             SourceLocation RBrac,
4673                                             AttributeList *AttrList) {
4674  if (!TagDecl)
4675    return;
4676
4677  AdjustDeclIfTemplate(TagDecl);
4678
4679  ActOnFields(S, RLoc, TagDecl, llvm::makeArrayRef(
4680              // strict aliasing violation!
4681              reinterpret_cast<Decl**>(FieldCollector->getCurFields()),
4682              FieldCollector->getCurNumFields()), LBrac, RBrac, AttrList);
4683
4684  CheckCompletedCXXClass(
4685                        dyn_cast_or_null<CXXRecordDecl>(TagDecl));
4686}
4687
4688/// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared
4689/// special functions, such as the default constructor, copy
4690/// constructor, or destructor, to the given C++ class (C++
4691/// [special]p1).  This routine can only be executed just before the
4692/// definition of the class is complete.
4693void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) {
4694  if (!ClassDecl->hasUserDeclaredConstructor())
4695    ++ASTContext::NumImplicitDefaultConstructors;
4696
4697  if (!ClassDecl->hasUserDeclaredCopyConstructor())
4698    ++ASTContext::NumImplicitCopyConstructors;
4699
4700  if (getLangOpts().CPlusPlus0x && ClassDecl->needsImplicitMoveConstructor())
4701    ++ASTContext::NumImplicitMoveConstructors;
4702
4703  if (!ClassDecl->hasUserDeclaredCopyAssignment()) {
4704    ++ASTContext::NumImplicitCopyAssignmentOperators;
4705
4706    // If we have a dynamic class, then the copy assignment operator may be
4707    // virtual, so we have to declare it immediately. This ensures that, e.g.,
4708    // it shows up in the right place in the vtable and that we diagnose
4709    // problems with the implicit exception specification.
4710    if (ClassDecl->isDynamicClass())
4711      DeclareImplicitCopyAssignment(ClassDecl);
4712  }
4713
4714  if (getLangOpts().CPlusPlus0x && ClassDecl->needsImplicitMoveAssignment()) {
4715    ++ASTContext::NumImplicitMoveAssignmentOperators;
4716
4717    // Likewise for the move assignment operator.
4718    if (ClassDecl->isDynamicClass())
4719      DeclareImplicitMoveAssignment(ClassDecl);
4720  }
4721
4722  if (!ClassDecl->hasUserDeclaredDestructor()) {
4723    ++ASTContext::NumImplicitDestructors;
4724
4725    // If we have a dynamic class, then the destructor may be virtual, so we
4726    // have to declare the destructor immediately. This ensures that, e.g., it
4727    // shows up in the right place in the vtable and that we diagnose problems
4728    // with the implicit exception specification.
4729    if (ClassDecl->isDynamicClass())
4730      DeclareImplicitDestructor(ClassDecl);
4731  }
4732}
4733
4734void Sema::ActOnReenterDeclaratorTemplateScope(Scope *S, DeclaratorDecl *D) {
4735  if (!D)
4736    return;
4737
4738  int NumParamList = D->getNumTemplateParameterLists();
4739  for (int i = 0; i < NumParamList; i++) {
4740    TemplateParameterList* Params = D->getTemplateParameterList(i);
4741    for (TemplateParameterList::iterator Param = Params->begin(),
4742                                      ParamEnd = Params->end();
4743          Param != ParamEnd; ++Param) {
4744      NamedDecl *Named = cast<NamedDecl>(*Param);
4745      if (Named->getDeclName()) {
4746        S->AddDecl(Named);
4747        IdResolver.AddDecl(Named);
4748      }
4749    }
4750  }
4751}
4752
4753void Sema::ActOnReenterTemplateScope(Scope *S, Decl *D) {
4754  if (!D)
4755    return;
4756
4757  TemplateParameterList *Params = 0;
4758  if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D))
4759    Params = Template->getTemplateParameters();
4760  else if (ClassTemplatePartialSpecializationDecl *PartialSpec
4761           = dyn_cast<ClassTemplatePartialSpecializationDecl>(D))
4762    Params = PartialSpec->getTemplateParameters();
4763  else
4764    return;
4765
4766  for (TemplateParameterList::iterator Param = Params->begin(),
4767                                    ParamEnd = Params->end();
4768       Param != ParamEnd; ++Param) {
4769    NamedDecl *Named = cast<NamedDecl>(*Param);
4770    if (Named->getDeclName()) {
4771      S->AddDecl(Named);
4772      IdResolver.AddDecl(Named);
4773    }
4774  }
4775}
4776
4777void Sema::ActOnStartDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
4778  if (!RecordD) return;
4779  AdjustDeclIfTemplate(RecordD);
4780  CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordD);
4781  PushDeclContext(S, Record);
4782}
4783
4784void Sema::ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
4785  if (!RecordD) return;
4786  PopDeclContext();
4787}
4788
4789/// ActOnStartDelayedCXXMethodDeclaration - We have completed
4790/// parsing a top-level (non-nested) C++ class, and we are now
4791/// parsing those parts of the given Method declaration that could
4792/// not be parsed earlier (C++ [class.mem]p2), such as default
4793/// arguments. This action should enter the scope of the given
4794/// Method declaration as if we had just parsed the qualified method
4795/// name. However, it should not bring the parameters into scope;
4796/// that will be performed by ActOnDelayedCXXMethodParameter.
4797void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
4798}
4799
4800/// ActOnDelayedCXXMethodParameter - We've already started a delayed
4801/// C++ method declaration. We're (re-)introducing the given
4802/// function parameter into scope for use in parsing later parts of
4803/// the method declaration. For example, we could see an
4804/// ActOnParamDefaultArgument event for this parameter.
4805void Sema::ActOnDelayedCXXMethodParameter(Scope *S, Decl *ParamD) {
4806  if (!ParamD)
4807    return;
4808
4809  ParmVarDecl *Param = cast<ParmVarDecl>(ParamD);
4810
4811  // If this parameter has an unparsed default argument, clear it out
4812  // to make way for the parsed default argument.
4813  if (Param->hasUnparsedDefaultArg())
4814    Param->setDefaultArg(0);
4815
4816  S->AddDecl(Param);
4817  if (Param->getDeclName())
4818    IdResolver.AddDecl(Param);
4819}
4820
4821/// ActOnFinishDelayedCXXMethodDeclaration - We have finished
4822/// processing the delayed method declaration for Method. The method
4823/// declaration is now considered finished. There may be a separate
4824/// ActOnStartOfFunctionDef action later (not necessarily
4825/// immediately!) for this method, if it was also defined inside the
4826/// class body.
4827void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
4828  if (!MethodD)
4829    return;
4830
4831  AdjustDeclIfTemplate(MethodD);
4832
4833  FunctionDecl *Method = cast<FunctionDecl>(MethodD);
4834
4835  // Now that we have our default arguments, check the constructor
4836  // again. It could produce additional diagnostics or affect whether
4837  // the class has implicitly-declared destructors, among other
4838  // things.
4839  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method))
4840    CheckConstructor(Constructor);
4841
4842  // Check the default arguments, which we may have added.
4843  if (!Method->isInvalidDecl())
4844    CheckCXXDefaultArguments(Method);
4845}
4846
4847/// CheckConstructorDeclarator - Called by ActOnDeclarator to check
4848/// the well-formedness of the constructor declarator @p D with type @p
4849/// R. If there are any errors in the declarator, this routine will
4850/// emit diagnostics and set the invalid bit to true.  In any case, the type
4851/// will be updated to reflect a well-formed type for the constructor and
4852/// returned.
4853QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R,
4854                                          StorageClass &SC) {
4855  bool isVirtual = D.getDeclSpec().isVirtualSpecified();
4856
4857  // C++ [class.ctor]p3:
4858  //   A constructor shall not be virtual (10.3) or static (9.4). A
4859  //   constructor can be invoked for a const, volatile or const
4860  //   volatile object. A constructor shall not be declared const,
4861  //   volatile, or const volatile (9.3.2).
4862  if (isVirtual) {
4863    if (!D.isInvalidType())
4864      Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
4865        << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc())
4866        << SourceRange(D.getIdentifierLoc());
4867    D.setInvalidType();
4868  }
4869  if (SC == SC_Static) {
4870    if (!D.isInvalidType())
4871      Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
4872        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
4873        << SourceRange(D.getIdentifierLoc());
4874    D.setInvalidType();
4875    SC = SC_None;
4876  }
4877
4878  DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
4879  if (FTI.TypeQuals != 0) {
4880    if (FTI.TypeQuals & Qualifiers::Const)
4881      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
4882        << "const" << SourceRange(D.getIdentifierLoc());
4883    if (FTI.TypeQuals & Qualifiers::Volatile)
4884      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
4885        << "volatile" << SourceRange(D.getIdentifierLoc());
4886    if (FTI.TypeQuals & Qualifiers::Restrict)
4887      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
4888        << "restrict" << SourceRange(D.getIdentifierLoc());
4889    D.setInvalidType();
4890  }
4891
4892  // C++0x [class.ctor]p4:
4893  //   A constructor shall not be declared with a ref-qualifier.
4894  if (FTI.hasRefQualifier()) {
4895    Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_constructor)
4896      << FTI.RefQualifierIsLValueRef
4897      << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
4898    D.setInvalidType();
4899  }
4900
4901  // Rebuild the function type "R" without any type qualifiers (in
4902  // case any of the errors above fired) and with "void" as the
4903  // return type, since constructors don't have return types.
4904  const FunctionProtoType *Proto = R->getAs<FunctionProtoType>();
4905  if (Proto->getResultType() == Context.VoidTy && !D.isInvalidType())
4906    return R;
4907
4908  FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
4909  EPI.TypeQuals = 0;
4910  EPI.RefQualifier = RQ_None;
4911
4912  return Context.getFunctionType(Context.VoidTy, Proto->arg_type_begin(),
4913                                 Proto->getNumArgs(), EPI);
4914}
4915
4916/// CheckConstructor - Checks a fully-formed constructor for
4917/// well-formedness, issuing any diagnostics required. Returns true if
4918/// the constructor declarator is invalid.
4919void Sema::CheckConstructor(CXXConstructorDecl *Constructor) {
4920  CXXRecordDecl *ClassDecl
4921    = dyn_cast<CXXRecordDecl>(Constructor->getDeclContext());
4922  if (!ClassDecl)
4923    return Constructor->setInvalidDecl();
4924
4925  // C++ [class.copy]p3:
4926  //   A declaration of a constructor for a class X is ill-formed if
4927  //   its first parameter is of type (optionally cv-qualified) X and
4928  //   either there are no other parameters or else all other
4929  //   parameters have default arguments.
4930  if (!Constructor->isInvalidDecl() &&
4931      ((Constructor->getNumParams() == 1) ||
4932       (Constructor->getNumParams() > 1 &&
4933        Constructor->getParamDecl(1)->hasDefaultArg())) &&
4934      Constructor->getTemplateSpecializationKind()
4935                                              != TSK_ImplicitInstantiation) {
4936    QualType ParamType = Constructor->getParamDecl(0)->getType();
4937    QualType ClassTy = Context.getTagDeclType(ClassDecl);
4938    if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) {
4939      SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation();
4940      const char *ConstRef
4941        = Constructor->getParamDecl(0)->getIdentifier() ? "const &"
4942                                                        : " const &";
4943      Diag(ParamLoc, diag::err_constructor_byvalue_arg)
4944        << FixItHint::CreateInsertion(ParamLoc, ConstRef);
4945
4946      // FIXME: Rather that making the constructor invalid, we should endeavor
4947      // to fix the type.
4948      Constructor->setInvalidDecl();
4949    }
4950  }
4951}
4952
4953/// CheckDestructor - Checks a fully-formed destructor definition for
4954/// well-formedness, issuing any diagnostics required.  Returns true
4955/// on error.
4956bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) {
4957  CXXRecordDecl *RD = Destructor->getParent();
4958
4959  if (Destructor->isVirtual()) {
4960    SourceLocation Loc;
4961
4962    if (!Destructor->isImplicit())
4963      Loc = Destructor->getLocation();
4964    else
4965      Loc = RD->getLocation();
4966
4967    // If we have a virtual destructor, look up the deallocation function
4968    FunctionDecl *OperatorDelete = 0;
4969    DeclarationName Name =
4970    Context.DeclarationNames.getCXXOperatorName(OO_Delete);
4971    if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete))
4972      return true;
4973
4974    MarkFunctionReferenced(Loc, OperatorDelete);
4975
4976    Destructor->setOperatorDelete(OperatorDelete);
4977  }
4978
4979  return false;
4980}
4981
4982static inline bool
4983FTIHasSingleVoidArgument(DeclaratorChunk::FunctionTypeInfo &FTI) {
4984  return (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 &&
4985          FTI.ArgInfo[0].Param &&
4986          cast<ParmVarDecl>(FTI.ArgInfo[0].Param)->getType()->isVoidType());
4987}
4988
4989/// CheckDestructorDeclarator - Called by ActOnDeclarator to check
4990/// the well-formednes of the destructor declarator @p D with type @p
4991/// R. If there are any errors in the declarator, this routine will
4992/// emit diagnostics and set the declarator to invalid.  Even if this happens,
4993/// will be updated to reflect a well-formed type for the destructor and
4994/// returned.
4995QualType Sema::CheckDestructorDeclarator(Declarator &D, QualType R,
4996                                         StorageClass& SC) {
4997  // C++ [class.dtor]p1:
4998  //   [...] A typedef-name that names a class is a class-name
4999  //   (7.1.3); however, a typedef-name that names a class shall not
5000  //   be used as the identifier in the declarator for a destructor
5001  //   declaration.
5002  QualType DeclaratorType = GetTypeFromParser(D.getName().DestructorName);
5003  if (const TypedefType *TT = DeclaratorType->getAs<TypedefType>())
5004    Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name)
5005      << DeclaratorType << isa<TypeAliasDecl>(TT->getDecl());
5006  else if (const TemplateSpecializationType *TST =
5007             DeclaratorType->getAs<TemplateSpecializationType>())
5008    if (TST->isTypeAlias())
5009      Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name)
5010        << DeclaratorType << 1;
5011
5012  // C++ [class.dtor]p2:
5013  //   A destructor is used to destroy objects of its class type. A
5014  //   destructor takes no parameters, and no return type can be
5015  //   specified for it (not even void). The address of a destructor
5016  //   shall not be taken. A destructor shall not be static. A
5017  //   destructor can be invoked for a const, volatile or const
5018  //   volatile object. A destructor shall not be declared const,
5019  //   volatile or const volatile (9.3.2).
5020  if (SC == SC_Static) {
5021    if (!D.isInvalidType())
5022      Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be)
5023        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
5024        << SourceRange(D.getIdentifierLoc())
5025        << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
5026
5027    SC = SC_None;
5028  }
5029  if (D.getDeclSpec().hasTypeSpecifier() && !D.isInvalidType()) {
5030    // Destructors don't have return types, but the parser will
5031    // happily parse something like:
5032    //
5033    //   class X {
5034    //     float ~X();
5035    //   };
5036    //
5037    // The return type will be eliminated later.
5038    Diag(D.getIdentifierLoc(), diag::err_destructor_return_type)
5039      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
5040      << SourceRange(D.getIdentifierLoc());
5041  }
5042
5043  DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
5044  if (FTI.TypeQuals != 0 && !D.isInvalidType()) {
5045    if (FTI.TypeQuals & Qualifiers::Const)
5046      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
5047        << "const" << SourceRange(D.getIdentifierLoc());
5048    if (FTI.TypeQuals & Qualifiers::Volatile)
5049      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
5050        << "volatile" << SourceRange(D.getIdentifierLoc());
5051    if (FTI.TypeQuals & Qualifiers::Restrict)
5052      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
5053        << "restrict" << SourceRange(D.getIdentifierLoc());
5054    D.setInvalidType();
5055  }
5056
5057  // C++0x [class.dtor]p2:
5058  //   A destructor shall not be declared with a ref-qualifier.
5059  if (FTI.hasRefQualifier()) {
5060    Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_destructor)
5061      << FTI.RefQualifierIsLValueRef
5062      << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
5063    D.setInvalidType();
5064  }
5065
5066  // Make sure we don't have any parameters.
5067  if (FTI.NumArgs > 0 && !FTIHasSingleVoidArgument(FTI)) {
5068    Diag(D.getIdentifierLoc(), diag::err_destructor_with_params);
5069
5070    // Delete the parameters.
5071    FTI.freeArgs();
5072    D.setInvalidType();
5073  }
5074
5075  // Make sure the destructor isn't variadic.
5076  if (FTI.isVariadic) {
5077    Diag(D.getIdentifierLoc(), diag::err_destructor_variadic);
5078    D.setInvalidType();
5079  }
5080
5081  // Rebuild the function type "R" without any type qualifiers or
5082  // parameters (in case any of the errors above fired) and with
5083  // "void" as the return type, since destructors don't have return
5084  // types.
5085  if (!D.isInvalidType())
5086    return R;
5087
5088  const FunctionProtoType *Proto = R->getAs<FunctionProtoType>();
5089  FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
5090  EPI.Variadic = false;
5091  EPI.TypeQuals = 0;
5092  EPI.RefQualifier = RQ_None;
5093  return Context.getFunctionType(Context.VoidTy, 0, 0, EPI);
5094}
5095
5096/// CheckConversionDeclarator - Called by ActOnDeclarator to check the
5097/// well-formednes of the conversion function declarator @p D with
5098/// type @p R. If there are any errors in the declarator, this routine
5099/// will emit diagnostics and return true. Otherwise, it will return
5100/// false. Either way, the type @p R will be updated to reflect a
5101/// well-formed type for the conversion operator.
5102void Sema::CheckConversionDeclarator(Declarator &D, QualType &R,
5103                                     StorageClass& SC) {
5104  // C++ [class.conv.fct]p1:
5105  //   Neither parameter types nor return type can be specified. The
5106  //   type of a conversion function (8.3.5) is "function taking no
5107  //   parameter returning conversion-type-id."
5108  if (SC == SC_Static) {
5109    if (!D.isInvalidType())
5110      Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member)
5111        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
5112        << SourceRange(D.getIdentifierLoc());
5113    D.setInvalidType();
5114    SC = SC_None;
5115  }
5116
5117  QualType ConvType = GetTypeFromParser(D.getName().ConversionFunctionId);
5118
5119  if (D.getDeclSpec().hasTypeSpecifier() && !D.isInvalidType()) {
5120    // Conversion functions don't have return types, but the parser will
5121    // happily parse something like:
5122    //
5123    //   class X {
5124    //     float operator bool();
5125    //   };
5126    //
5127    // The return type will be changed later anyway.
5128    Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type)
5129      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
5130      << SourceRange(D.getIdentifierLoc());
5131    D.setInvalidType();
5132  }
5133
5134  const FunctionProtoType *Proto = R->getAs<FunctionProtoType>();
5135
5136  // Make sure we don't have any parameters.
5137  if (Proto->getNumArgs() > 0) {
5138    Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params);
5139
5140    // Delete the parameters.
5141    D.getFunctionTypeInfo().freeArgs();
5142    D.setInvalidType();
5143  } else if (Proto->isVariadic()) {
5144    Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic);
5145    D.setInvalidType();
5146  }
5147
5148  // Diagnose "&operator bool()" and other such nonsense.  This
5149  // is actually a gcc extension which we don't support.
5150  if (Proto->getResultType() != ConvType) {
5151    Diag(D.getIdentifierLoc(), diag::err_conv_function_with_complex_decl)
5152      << Proto->getResultType();
5153    D.setInvalidType();
5154    ConvType = Proto->getResultType();
5155  }
5156
5157  // C++ [class.conv.fct]p4:
5158  //   The conversion-type-id shall not represent a function type nor
5159  //   an array type.
5160  if (ConvType->isArrayType()) {
5161    Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array);
5162    ConvType = Context.getPointerType(ConvType);
5163    D.setInvalidType();
5164  } else if (ConvType->isFunctionType()) {
5165    Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function);
5166    ConvType = Context.getPointerType(ConvType);
5167    D.setInvalidType();
5168  }
5169
5170  // Rebuild the function type "R" without any parameters (in case any
5171  // of the errors above fired) and with the conversion type as the
5172  // return type.
5173  if (D.isInvalidType())
5174    R = Context.getFunctionType(ConvType, 0, 0, Proto->getExtProtoInfo());
5175
5176  // C++0x explicit conversion operators.
5177  if (D.getDeclSpec().isExplicitSpecified())
5178    Diag(D.getDeclSpec().getExplicitSpecLoc(),
5179         getLangOpts().CPlusPlus0x ?
5180           diag::warn_cxx98_compat_explicit_conversion_functions :
5181           diag::ext_explicit_conversion_functions)
5182      << SourceRange(D.getDeclSpec().getExplicitSpecLoc());
5183}
5184
5185/// ActOnConversionDeclarator - Called by ActOnDeclarator to complete
5186/// the declaration of the given C++ conversion function. This routine
5187/// is responsible for recording the conversion function in the C++
5188/// class, if possible.
5189Decl *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) {
5190  assert(Conversion && "Expected to receive a conversion function declaration");
5191
5192  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext());
5193
5194  // Make sure we aren't redeclaring the conversion function.
5195  QualType ConvType = Context.getCanonicalType(Conversion->getConversionType());
5196
5197  // C++ [class.conv.fct]p1:
5198  //   [...] A conversion function is never used to convert a
5199  //   (possibly cv-qualified) object to the (possibly cv-qualified)
5200  //   same object type (or a reference to it), to a (possibly
5201  //   cv-qualified) base class of that type (or a reference to it),
5202  //   or to (possibly cv-qualified) void.
5203  // FIXME: Suppress this warning if the conversion function ends up being a
5204  // virtual function that overrides a virtual function in a base class.
5205  QualType ClassType
5206    = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
5207  if (const ReferenceType *ConvTypeRef = ConvType->getAs<ReferenceType>())
5208    ConvType = ConvTypeRef->getPointeeType();
5209  if (Conversion->getTemplateSpecializationKind() != TSK_Undeclared &&
5210      Conversion->getTemplateSpecializationKind() != TSK_ExplicitSpecialization)
5211    /* Suppress diagnostics for instantiations. */;
5212  else if (ConvType->isRecordType()) {
5213    ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType();
5214    if (ConvType == ClassType)
5215      Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used)
5216        << ClassType;
5217    else if (IsDerivedFrom(ClassType, ConvType))
5218      Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used)
5219        <<  ClassType << ConvType;
5220  } else if (ConvType->isVoidType()) {
5221    Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used)
5222      << ClassType << ConvType;
5223  }
5224
5225  if (FunctionTemplateDecl *ConversionTemplate
5226                                = Conversion->getDescribedFunctionTemplate())
5227    return ConversionTemplate;
5228
5229  return Conversion;
5230}
5231
5232//===----------------------------------------------------------------------===//
5233// Namespace Handling
5234//===----------------------------------------------------------------------===//
5235
5236
5237
5238/// ActOnStartNamespaceDef - This is called at the start of a namespace
5239/// definition.
5240Decl *Sema::ActOnStartNamespaceDef(Scope *NamespcScope,
5241                                   SourceLocation InlineLoc,
5242                                   SourceLocation NamespaceLoc,
5243                                   SourceLocation IdentLoc,
5244                                   IdentifierInfo *II,
5245                                   SourceLocation LBrace,
5246                                   AttributeList *AttrList) {
5247  SourceLocation StartLoc = InlineLoc.isValid() ? InlineLoc : NamespaceLoc;
5248  // For anonymous namespace, take the location of the left brace.
5249  SourceLocation Loc = II ? IdentLoc : LBrace;
5250  bool IsInline = InlineLoc.isValid();
5251  bool IsInvalid = false;
5252  bool IsStd = false;
5253  bool AddToKnown = false;
5254  Scope *DeclRegionScope = NamespcScope->getParent();
5255
5256  NamespaceDecl *PrevNS = 0;
5257  if (II) {
5258    // C++ [namespace.def]p2:
5259    //   The identifier in an original-namespace-definition shall not
5260    //   have been previously defined in the declarative region in
5261    //   which the original-namespace-definition appears. The
5262    //   identifier in an original-namespace-definition is the name of
5263    //   the namespace. Subsequently in that declarative region, it is
5264    //   treated as an original-namespace-name.
5265    //
5266    // Since namespace names are unique in their scope, and we don't
5267    // look through using directives, just look for any ordinary names.
5268
5269    const unsigned IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Member |
5270    Decl::IDNS_Type | Decl::IDNS_Using | Decl::IDNS_Tag |
5271    Decl::IDNS_Namespace;
5272    NamedDecl *PrevDecl = 0;
5273    for (DeclContext::lookup_result R
5274         = CurContext->getRedeclContext()->lookup(II);
5275         R.first != R.second; ++R.first) {
5276      if ((*R.first)->getIdentifierNamespace() & IDNS) {
5277        PrevDecl = *R.first;
5278        break;
5279      }
5280    }
5281
5282    PrevNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl);
5283
5284    if (PrevNS) {
5285      // This is an extended namespace definition.
5286      if (IsInline != PrevNS->isInline()) {
5287        // inline-ness must match
5288        if (PrevNS->isInline()) {
5289          // The user probably just forgot the 'inline', so suggest that it
5290          // be added back.
5291          Diag(Loc, diag::warn_inline_namespace_reopened_noninline)
5292            << FixItHint::CreateInsertion(NamespaceLoc, "inline ");
5293        } else {
5294          Diag(Loc, diag::err_inline_namespace_mismatch)
5295            << IsInline;
5296        }
5297        Diag(PrevNS->getLocation(), diag::note_previous_definition);
5298
5299        IsInline = PrevNS->isInline();
5300      }
5301    } else if (PrevDecl) {
5302      // This is an invalid name redefinition.
5303      Diag(Loc, diag::err_redefinition_different_kind)
5304        << II;
5305      Diag(PrevDecl->getLocation(), diag::note_previous_definition);
5306      IsInvalid = true;
5307      // Continue on to push Namespc as current DeclContext and return it.
5308    } else if (II->isStr("std") &&
5309               CurContext->getRedeclContext()->isTranslationUnit()) {
5310      // This is the first "real" definition of the namespace "std", so update
5311      // our cache of the "std" namespace to point at this definition.
5312      PrevNS = getStdNamespace();
5313      IsStd = true;
5314      AddToKnown = !IsInline;
5315    } else {
5316      // We've seen this namespace for the first time.
5317      AddToKnown = !IsInline;
5318    }
5319  } else {
5320    // Anonymous namespaces.
5321
5322    // Determine whether the parent already has an anonymous namespace.
5323    DeclContext *Parent = CurContext->getRedeclContext();
5324    if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
5325      PrevNS = TU->getAnonymousNamespace();
5326    } else {
5327      NamespaceDecl *ND = cast<NamespaceDecl>(Parent);
5328      PrevNS = ND->getAnonymousNamespace();
5329    }
5330
5331    if (PrevNS && IsInline != PrevNS->isInline()) {
5332      // inline-ness must match
5333      Diag(Loc, diag::err_inline_namespace_mismatch)
5334        << IsInline;
5335      Diag(PrevNS->getLocation(), diag::note_previous_definition);
5336
5337      // Recover by ignoring the new namespace's inline status.
5338      IsInline = PrevNS->isInline();
5339    }
5340  }
5341
5342  NamespaceDecl *Namespc = NamespaceDecl::Create(Context, CurContext, IsInline,
5343                                                 StartLoc, Loc, II, PrevNS);
5344  if (IsInvalid)
5345    Namespc->setInvalidDecl();
5346
5347  ProcessDeclAttributeList(DeclRegionScope, Namespc, AttrList);
5348
5349  // FIXME: Should we be merging attributes?
5350  if (const VisibilityAttr *Attr = Namespc->getAttr<VisibilityAttr>())
5351    PushNamespaceVisibilityAttr(Attr, Loc);
5352
5353  if (IsStd)
5354    StdNamespace = Namespc;
5355  if (AddToKnown)
5356    KnownNamespaces[Namespc] = false;
5357
5358  if (II) {
5359    PushOnScopeChains(Namespc, DeclRegionScope);
5360  } else {
5361    // Link the anonymous namespace into its parent.
5362    DeclContext *Parent = CurContext->getRedeclContext();
5363    if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
5364      TU->setAnonymousNamespace(Namespc);
5365    } else {
5366      cast<NamespaceDecl>(Parent)->setAnonymousNamespace(Namespc);
5367    }
5368
5369    CurContext->addDecl(Namespc);
5370
5371    // C++ [namespace.unnamed]p1.  An unnamed-namespace-definition
5372    //   behaves as if it were replaced by
5373    //     namespace unique { /* empty body */ }
5374    //     using namespace unique;
5375    //     namespace unique { namespace-body }
5376    //   where all occurrences of 'unique' in a translation unit are
5377    //   replaced by the same identifier and this identifier differs
5378    //   from all other identifiers in the entire program.
5379
5380    // We just create the namespace with an empty name and then add an
5381    // implicit using declaration, just like the standard suggests.
5382    //
5383    // CodeGen enforces the "universally unique" aspect by giving all
5384    // declarations semantically contained within an anonymous
5385    // namespace internal linkage.
5386
5387    if (!PrevNS) {
5388      UsingDirectiveDecl* UD
5389        = UsingDirectiveDecl::Create(Context, CurContext,
5390                                     /* 'using' */ LBrace,
5391                                     /* 'namespace' */ SourceLocation(),
5392                                     /* qualifier */ NestedNameSpecifierLoc(),
5393                                     /* identifier */ SourceLocation(),
5394                                     Namespc,
5395                                     /* Ancestor */ CurContext);
5396      UD->setImplicit();
5397      CurContext->addDecl(UD);
5398    }
5399  }
5400
5401  // Although we could have an invalid decl (i.e. the namespace name is a
5402  // redefinition), push it as current DeclContext and try to continue parsing.
5403  // FIXME: We should be able to push Namespc here, so that the each DeclContext
5404  // for the namespace has the declarations that showed up in that particular
5405  // namespace definition.
5406  PushDeclContext(NamespcScope, Namespc);
5407  return Namespc;
5408}
5409
5410/// getNamespaceDecl - Returns the namespace a decl represents. If the decl
5411/// is a namespace alias, returns the namespace it points to.
5412static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) {
5413  if (NamespaceAliasDecl *AD = dyn_cast_or_null<NamespaceAliasDecl>(D))
5414    return AD->getNamespace();
5415  return dyn_cast_or_null<NamespaceDecl>(D);
5416}
5417
5418/// ActOnFinishNamespaceDef - This callback is called after a namespace is
5419/// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef.
5420void Sema::ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace) {
5421  NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl);
5422  assert(Namespc && "Invalid parameter, expected NamespaceDecl");
5423  Namespc->setRBraceLoc(RBrace);
5424  PopDeclContext();
5425  if (Namespc->hasAttr<VisibilityAttr>())
5426    PopPragmaVisibility(true, RBrace);
5427}
5428
5429CXXRecordDecl *Sema::getStdBadAlloc() const {
5430  return cast_or_null<CXXRecordDecl>(
5431                                  StdBadAlloc.get(Context.getExternalSource()));
5432}
5433
5434NamespaceDecl *Sema::getStdNamespace() const {
5435  return cast_or_null<NamespaceDecl>(
5436                                 StdNamespace.get(Context.getExternalSource()));
5437}
5438
5439/// \brief Retrieve the special "std" namespace, which may require us to
5440/// implicitly define the namespace.
5441NamespaceDecl *Sema::getOrCreateStdNamespace() {
5442  if (!StdNamespace) {
5443    // The "std" namespace has not yet been defined, so build one implicitly.
5444    StdNamespace = NamespaceDecl::Create(Context,
5445                                         Context.getTranslationUnitDecl(),
5446                                         /*Inline=*/false,
5447                                         SourceLocation(), SourceLocation(),
5448                                         &PP.getIdentifierTable().get("std"),
5449                                         /*PrevDecl=*/0);
5450    getStdNamespace()->setImplicit(true);
5451  }
5452
5453  return getStdNamespace();
5454}
5455
5456bool Sema::isStdInitializerList(QualType Ty, QualType *Element) {
5457  assert(getLangOpts().CPlusPlus &&
5458         "Looking for std::initializer_list outside of C++.");
5459
5460  // We're looking for implicit instantiations of
5461  // template <typename E> class std::initializer_list.
5462
5463  if (!StdNamespace) // If we haven't seen namespace std yet, this can't be it.
5464    return false;
5465
5466  ClassTemplateDecl *Template = 0;
5467  const TemplateArgument *Arguments = 0;
5468
5469  if (const RecordType *RT = Ty->getAs<RecordType>()) {
5470
5471    ClassTemplateSpecializationDecl *Specialization =
5472        dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl());
5473    if (!Specialization)
5474      return false;
5475
5476    Template = Specialization->getSpecializedTemplate();
5477    Arguments = Specialization->getTemplateArgs().data();
5478  } else if (const TemplateSpecializationType *TST =
5479                 Ty->getAs<TemplateSpecializationType>()) {
5480    Template = dyn_cast_or_null<ClassTemplateDecl>(
5481        TST->getTemplateName().getAsTemplateDecl());
5482    Arguments = TST->getArgs();
5483  }
5484  if (!Template)
5485    return false;
5486
5487  if (!StdInitializerList) {
5488    // Haven't recognized std::initializer_list yet, maybe this is it.
5489    CXXRecordDecl *TemplateClass = Template->getTemplatedDecl();
5490    if (TemplateClass->getIdentifier() !=
5491            &PP.getIdentifierTable().get("initializer_list") ||
5492        !getStdNamespace()->InEnclosingNamespaceSetOf(
5493            TemplateClass->getDeclContext()))
5494      return false;
5495    // This is a template called std::initializer_list, but is it the right
5496    // template?
5497    TemplateParameterList *Params = Template->getTemplateParameters();
5498    if (Params->getMinRequiredArguments() != 1)
5499      return false;
5500    if (!isa<TemplateTypeParmDecl>(Params->getParam(0)))
5501      return false;
5502
5503    // It's the right template.
5504    StdInitializerList = Template;
5505  }
5506
5507  if (Template != StdInitializerList)
5508    return false;
5509
5510  // This is an instance of std::initializer_list. Find the argument type.
5511  if (Element)
5512    *Element = Arguments[0].getAsType();
5513  return true;
5514}
5515
5516static ClassTemplateDecl *LookupStdInitializerList(Sema &S, SourceLocation Loc){
5517  NamespaceDecl *Std = S.getStdNamespace();
5518  if (!Std) {
5519    S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
5520    return 0;
5521  }
5522
5523  LookupResult Result(S, &S.PP.getIdentifierTable().get("initializer_list"),
5524                      Loc, Sema::LookupOrdinaryName);
5525  if (!S.LookupQualifiedName(Result, Std)) {
5526    S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
5527    return 0;
5528  }
5529  ClassTemplateDecl *Template = Result.getAsSingle<ClassTemplateDecl>();
5530  if (!Template) {
5531    Result.suppressDiagnostics();
5532    // We found something weird. Complain about the first thing we found.
5533    NamedDecl *Found = *Result.begin();
5534    S.Diag(Found->getLocation(), diag::err_malformed_std_initializer_list);
5535    return 0;
5536  }
5537
5538  // We found some template called std::initializer_list. Now verify that it's
5539  // correct.
5540  TemplateParameterList *Params = Template->getTemplateParameters();
5541  if (Params->getMinRequiredArguments() != 1 ||
5542      !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
5543    S.Diag(Template->getLocation(), diag::err_malformed_std_initializer_list);
5544    return 0;
5545  }
5546
5547  return Template;
5548}
5549
5550QualType Sema::BuildStdInitializerList(QualType Element, SourceLocation Loc) {
5551  if (!StdInitializerList) {
5552    StdInitializerList = LookupStdInitializerList(*this, Loc);
5553    if (!StdInitializerList)
5554      return QualType();
5555  }
5556
5557  TemplateArgumentListInfo Args(Loc, Loc);
5558  Args.addArgument(TemplateArgumentLoc(TemplateArgument(Element),
5559                                       Context.getTrivialTypeSourceInfo(Element,
5560                                                                        Loc)));
5561  return Context.getCanonicalType(
5562      CheckTemplateIdType(TemplateName(StdInitializerList), Loc, Args));
5563}
5564
5565bool Sema::isInitListConstructor(const CXXConstructorDecl* Ctor) {
5566  // C++ [dcl.init.list]p2:
5567  //   A constructor is an initializer-list constructor if its first parameter
5568  //   is of type std::initializer_list<E> or reference to possibly cv-qualified
5569  //   std::initializer_list<E> for some type E, and either there are no other
5570  //   parameters or else all other parameters have default arguments.
5571  if (Ctor->getNumParams() < 1 ||
5572      (Ctor->getNumParams() > 1 && !Ctor->getParamDecl(1)->hasDefaultArg()))
5573    return false;
5574
5575  QualType ArgType = Ctor->getParamDecl(0)->getType();
5576  if (const ReferenceType *RT = ArgType->getAs<ReferenceType>())
5577    ArgType = RT->getPointeeType().getUnqualifiedType();
5578
5579  return isStdInitializerList(ArgType, 0);
5580}
5581
5582/// \brief Determine whether a using statement is in a context where it will be
5583/// apply in all contexts.
5584static bool IsUsingDirectiveInToplevelContext(DeclContext *CurContext) {
5585  switch (CurContext->getDeclKind()) {
5586    case Decl::TranslationUnit:
5587      return true;
5588    case Decl::LinkageSpec:
5589      return IsUsingDirectiveInToplevelContext(CurContext->getParent());
5590    default:
5591      return false;
5592  }
5593}
5594
5595namespace {
5596
5597// Callback to only accept typo corrections that are namespaces.
5598class NamespaceValidatorCCC : public CorrectionCandidateCallback {
5599 public:
5600  virtual bool ValidateCandidate(const TypoCorrection &candidate) {
5601    if (NamedDecl *ND = candidate.getCorrectionDecl()) {
5602      return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND);
5603    }
5604    return false;
5605  }
5606};
5607
5608}
5609
5610static bool TryNamespaceTypoCorrection(Sema &S, LookupResult &R, Scope *Sc,
5611                                       CXXScopeSpec &SS,
5612                                       SourceLocation IdentLoc,
5613                                       IdentifierInfo *Ident) {
5614  NamespaceValidatorCCC Validator;
5615  R.clear();
5616  if (TypoCorrection Corrected = S.CorrectTypo(R.getLookupNameInfo(),
5617                                               R.getLookupKind(), Sc, &SS,
5618                                               Validator)) {
5619    std::string CorrectedStr(Corrected.getAsString(S.getLangOpts()));
5620    std::string CorrectedQuotedStr(Corrected.getQuoted(S.getLangOpts()));
5621    if (DeclContext *DC = S.computeDeclContext(SS, false))
5622      S.Diag(IdentLoc, diag::err_using_directive_member_suggest)
5623        << Ident << DC << CorrectedQuotedStr << SS.getRange()
5624        << FixItHint::CreateReplacement(IdentLoc, CorrectedStr);
5625    else
5626      S.Diag(IdentLoc, diag::err_using_directive_suggest)
5627        << Ident << CorrectedQuotedStr
5628        << FixItHint::CreateReplacement(IdentLoc, CorrectedStr);
5629
5630    S.Diag(Corrected.getCorrectionDecl()->getLocation(),
5631         diag::note_namespace_defined_here) << CorrectedQuotedStr;
5632
5633    R.addDecl(Corrected.getCorrectionDecl());
5634    return true;
5635  }
5636  return false;
5637}
5638
5639Decl *Sema::ActOnUsingDirective(Scope *S,
5640                                          SourceLocation UsingLoc,
5641                                          SourceLocation NamespcLoc,
5642                                          CXXScopeSpec &SS,
5643                                          SourceLocation IdentLoc,
5644                                          IdentifierInfo *NamespcName,
5645                                          AttributeList *AttrList) {
5646  assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
5647  assert(NamespcName && "Invalid NamespcName.");
5648  assert(IdentLoc.isValid() && "Invalid NamespceName location.");
5649
5650  // This can only happen along a recovery path.
5651  while (S->getFlags() & Scope::TemplateParamScope)
5652    S = S->getParent();
5653  assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
5654
5655  UsingDirectiveDecl *UDir = 0;
5656  NestedNameSpecifier *Qualifier = 0;
5657  if (SS.isSet())
5658    Qualifier = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
5659
5660  // Lookup namespace name.
5661  LookupResult R(*this, NamespcName, IdentLoc, LookupNamespaceName);
5662  LookupParsedName(R, S, &SS);
5663  if (R.isAmbiguous())
5664    return 0;
5665
5666  if (R.empty()) {
5667    R.clear();
5668    // Allow "using namespace std;" or "using namespace ::std;" even if
5669    // "std" hasn't been defined yet, for GCC compatibility.
5670    if ((!Qualifier || Qualifier->getKind() == NestedNameSpecifier::Global) &&
5671        NamespcName->isStr("std")) {
5672      Diag(IdentLoc, diag::ext_using_undefined_std);
5673      R.addDecl(getOrCreateStdNamespace());
5674      R.resolveKind();
5675    }
5676    // Otherwise, attempt typo correction.
5677    else TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, NamespcName);
5678  }
5679
5680  if (!R.empty()) {
5681    NamedDecl *Named = R.getFoundDecl();
5682    assert((isa<NamespaceDecl>(Named) || isa<NamespaceAliasDecl>(Named))
5683        && "expected namespace decl");
5684    // C++ [namespace.udir]p1:
5685    //   A using-directive specifies that the names in the nominated
5686    //   namespace can be used in the scope in which the
5687    //   using-directive appears after the using-directive. During
5688    //   unqualified name lookup (3.4.1), the names appear as if they
5689    //   were declared in the nearest enclosing namespace which
5690    //   contains both the using-directive and the nominated
5691    //   namespace. [Note: in this context, "contains" means "contains
5692    //   directly or indirectly". ]
5693
5694    // Find enclosing context containing both using-directive and
5695    // nominated namespace.
5696    NamespaceDecl *NS = getNamespaceDecl(Named);
5697    DeclContext *CommonAncestor = cast<DeclContext>(NS);
5698    while (CommonAncestor && !CommonAncestor->Encloses(CurContext))
5699      CommonAncestor = CommonAncestor->getParent();
5700
5701    UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc, NamespcLoc,
5702                                      SS.getWithLocInContext(Context),
5703                                      IdentLoc, Named, CommonAncestor);
5704
5705    if (IsUsingDirectiveInToplevelContext(CurContext) &&
5706        !SourceMgr.isFromMainFile(SourceMgr.getExpansionLoc(IdentLoc))) {
5707      Diag(IdentLoc, diag::warn_using_directive_in_header);
5708    }
5709
5710    PushUsingDirective(S, UDir);
5711  } else {
5712    Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
5713  }
5714
5715  // FIXME: We ignore attributes for now.
5716  return UDir;
5717}
5718
5719void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) {
5720  // If the scope has an associated entity and the using directive is at
5721  // namespace or translation unit scope, add the UsingDirectiveDecl into
5722  // its lookup structure so qualified name lookup can find it.
5723  DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity());
5724  if (Ctx && !Ctx->isFunctionOrMethod())
5725    Ctx->addDecl(UDir);
5726  else
5727    // Otherwise, it is at block sope. The using-directives will affect lookup
5728    // only to the end of the scope.
5729    S->PushUsingDirective(UDir);
5730}
5731
5732
5733Decl *Sema::ActOnUsingDeclaration(Scope *S,
5734                                  AccessSpecifier AS,
5735                                  bool HasUsingKeyword,
5736                                  SourceLocation UsingLoc,
5737                                  CXXScopeSpec &SS,
5738                                  UnqualifiedId &Name,
5739                                  AttributeList *AttrList,
5740                                  bool IsTypeName,
5741                                  SourceLocation TypenameLoc) {
5742  assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
5743
5744  switch (Name.getKind()) {
5745  case UnqualifiedId::IK_ImplicitSelfParam:
5746  case UnqualifiedId::IK_Identifier:
5747  case UnqualifiedId::IK_OperatorFunctionId:
5748  case UnqualifiedId::IK_LiteralOperatorId:
5749  case UnqualifiedId::IK_ConversionFunctionId:
5750    break;
5751
5752  case UnqualifiedId::IK_ConstructorName:
5753  case UnqualifiedId::IK_ConstructorTemplateId:
5754    // C++11 inheriting constructors.
5755    Diag(Name.getLocStart(),
5756         getLangOpts().CPlusPlus0x ?
5757           // FIXME: Produce warn_cxx98_compat_using_decl_constructor
5758           //        instead once inheriting constructors work.
5759           diag::err_using_decl_constructor_unsupported :
5760           diag::err_using_decl_constructor)
5761      << SS.getRange();
5762
5763    if (getLangOpts().CPlusPlus0x) break;
5764
5765    return 0;
5766
5767  case UnqualifiedId::IK_DestructorName:
5768    Diag(Name.getLocStart(), diag::err_using_decl_destructor)
5769      << SS.getRange();
5770    return 0;
5771
5772  case UnqualifiedId::IK_TemplateId:
5773    Diag(Name.getLocStart(), diag::err_using_decl_template_id)
5774      << SourceRange(Name.TemplateId->LAngleLoc, Name.TemplateId->RAngleLoc);
5775    return 0;
5776  }
5777
5778  DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name);
5779  DeclarationName TargetName = TargetNameInfo.getName();
5780  if (!TargetName)
5781    return 0;
5782
5783  // Warn about using declarations.
5784  // TODO: store that the declaration was written without 'using' and
5785  // talk about access decls instead of using decls in the
5786  // diagnostics.
5787  if (!HasUsingKeyword) {
5788    UsingLoc = Name.getLocStart();
5789
5790    Diag(UsingLoc, diag::warn_access_decl_deprecated)
5791      << FixItHint::CreateInsertion(SS.getRange().getBegin(), "using ");
5792  }
5793
5794  if (DiagnoseUnexpandedParameterPack(SS, UPPC_UsingDeclaration) ||
5795      DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC_UsingDeclaration))
5796    return 0;
5797
5798  NamedDecl *UD = BuildUsingDeclaration(S, AS, UsingLoc, SS,
5799                                        TargetNameInfo, AttrList,
5800                                        /* IsInstantiation */ false,
5801                                        IsTypeName, TypenameLoc);
5802  if (UD)
5803    PushOnScopeChains(UD, S, /*AddToContext*/ false);
5804
5805  return UD;
5806}
5807
5808/// \brief Determine whether a using declaration considers the given
5809/// declarations as "equivalent", e.g., if they are redeclarations of
5810/// the same entity or are both typedefs of the same type.
5811static bool
5812IsEquivalentForUsingDecl(ASTContext &Context, NamedDecl *D1, NamedDecl *D2,
5813                         bool &SuppressRedeclaration) {
5814  if (D1->getCanonicalDecl() == D2->getCanonicalDecl()) {
5815    SuppressRedeclaration = false;
5816    return true;
5817  }
5818
5819  if (TypedefNameDecl *TD1 = dyn_cast<TypedefNameDecl>(D1))
5820    if (TypedefNameDecl *TD2 = dyn_cast<TypedefNameDecl>(D2)) {
5821      SuppressRedeclaration = true;
5822      return Context.hasSameType(TD1->getUnderlyingType(),
5823                                 TD2->getUnderlyingType());
5824    }
5825
5826  return false;
5827}
5828
5829
5830/// Determines whether to create a using shadow decl for a particular
5831/// decl, given the set of decls existing prior to this using lookup.
5832bool Sema::CheckUsingShadowDecl(UsingDecl *Using, NamedDecl *Orig,
5833                                const LookupResult &Previous) {
5834  // Diagnose finding a decl which is not from a base class of the
5835  // current class.  We do this now because there are cases where this
5836  // function will silently decide not to build a shadow decl, which
5837  // will pre-empt further diagnostics.
5838  //
5839  // We don't need to do this in C++0x because we do the check once on
5840  // the qualifier.
5841  //
5842  // FIXME: diagnose the following if we care enough:
5843  //   struct A { int foo; };
5844  //   struct B : A { using A::foo; };
5845  //   template <class T> struct C : A {};
5846  //   template <class T> struct D : C<T> { using B::foo; } // <---
5847  // This is invalid (during instantiation) in C++03 because B::foo
5848  // resolves to the using decl in B, which is not a base class of D<T>.
5849  // We can't diagnose it immediately because C<T> is an unknown
5850  // specialization.  The UsingShadowDecl in D<T> then points directly
5851  // to A::foo, which will look well-formed when we instantiate.
5852  // The right solution is to not collapse the shadow-decl chain.
5853  if (!getLangOpts().CPlusPlus0x && CurContext->isRecord()) {
5854    DeclContext *OrigDC = Orig->getDeclContext();
5855
5856    // Handle enums and anonymous structs.
5857    if (isa<EnumDecl>(OrigDC)) OrigDC = OrigDC->getParent();
5858    CXXRecordDecl *OrigRec = cast<CXXRecordDecl>(OrigDC);
5859    while (OrigRec->isAnonymousStructOrUnion())
5860      OrigRec = cast<CXXRecordDecl>(OrigRec->getDeclContext());
5861
5862    if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(OrigRec)) {
5863      if (OrigDC == CurContext) {
5864        Diag(Using->getLocation(),
5865             diag::err_using_decl_nested_name_specifier_is_current_class)
5866          << Using->getQualifierLoc().getSourceRange();
5867        Diag(Orig->getLocation(), diag::note_using_decl_target);
5868        return true;
5869      }
5870
5871      Diag(Using->getQualifierLoc().getBeginLoc(),
5872           diag::err_using_decl_nested_name_specifier_is_not_base_class)
5873        << Using->getQualifier()
5874        << cast<CXXRecordDecl>(CurContext)
5875        << Using->getQualifierLoc().getSourceRange();
5876      Diag(Orig->getLocation(), diag::note_using_decl_target);
5877      return true;
5878    }
5879  }
5880
5881  if (Previous.empty()) return false;
5882
5883  NamedDecl *Target = Orig;
5884  if (isa<UsingShadowDecl>(Target))
5885    Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
5886
5887  // If the target happens to be one of the previous declarations, we
5888  // don't have a conflict.
5889  //
5890  // FIXME: but we might be increasing its access, in which case we
5891  // should redeclare it.
5892  NamedDecl *NonTag = 0, *Tag = 0;
5893  for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
5894         I != E; ++I) {
5895    NamedDecl *D = (*I)->getUnderlyingDecl();
5896    bool Result;
5897    if (IsEquivalentForUsingDecl(Context, D, Target, Result))
5898      return Result;
5899
5900    (isa<TagDecl>(D) ? Tag : NonTag) = D;
5901  }
5902
5903  if (Target->isFunctionOrFunctionTemplate()) {
5904    FunctionDecl *FD;
5905    if (isa<FunctionTemplateDecl>(Target))
5906      FD = cast<FunctionTemplateDecl>(Target)->getTemplatedDecl();
5907    else
5908      FD = cast<FunctionDecl>(Target);
5909
5910    NamedDecl *OldDecl = 0;
5911    switch (CheckOverload(0, FD, Previous, OldDecl, /*IsForUsingDecl*/ true)) {
5912    case Ovl_Overload:
5913      return false;
5914
5915    case Ovl_NonFunction:
5916      Diag(Using->getLocation(), diag::err_using_decl_conflict);
5917      break;
5918
5919    // We found a decl with the exact signature.
5920    case Ovl_Match:
5921      // If we're in a record, we want to hide the target, so we
5922      // return true (without a diagnostic) to tell the caller not to
5923      // build a shadow decl.
5924      if (CurContext->isRecord())
5925        return true;
5926
5927      // If we're not in a record, this is an error.
5928      Diag(Using->getLocation(), diag::err_using_decl_conflict);
5929      break;
5930    }
5931
5932    Diag(Target->getLocation(), diag::note_using_decl_target);
5933    Diag(OldDecl->getLocation(), diag::note_using_decl_conflict);
5934    return true;
5935  }
5936
5937  // Target is not a function.
5938
5939  if (isa<TagDecl>(Target)) {
5940    // No conflict between a tag and a non-tag.
5941    if (!Tag) return false;
5942
5943    Diag(Using->getLocation(), diag::err_using_decl_conflict);
5944    Diag(Target->getLocation(), diag::note_using_decl_target);
5945    Diag(Tag->getLocation(), diag::note_using_decl_conflict);
5946    return true;
5947  }
5948
5949  // No conflict between a tag and a non-tag.
5950  if (!NonTag) return false;
5951
5952  Diag(Using->getLocation(), diag::err_using_decl_conflict);
5953  Diag(Target->getLocation(), diag::note_using_decl_target);
5954  Diag(NonTag->getLocation(), diag::note_using_decl_conflict);
5955  return true;
5956}
5957
5958/// Builds a shadow declaration corresponding to a 'using' declaration.
5959UsingShadowDecl *Sema::BuildUsingShadowDecl(Scope *S,
5960                                            UsingDecl *UD,
5961                                            NamedDecl *Orig) {
5962
5963  // If we resolved to another shadow declaration, just coalesce them.
5964  NamedDecl *Target = Orig;
5965  if (isa<UsingShadowDecl>(Target)) {
5966    Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
5967    assert(!isa<UsingShadowDecl>(Target) && "nested shadow declaration");
5968  }
5969
5970  UsingShadowDecl *Shadow
5971    = UsingShadowDecl::Create(Context, CurContext,
5972                              UD->getLocation(), UD, Target);
5973  UD->addShadowDecl(Shadow);
5974
5975  Shadow->setAccess(UD->getAccess());
5976  if (Orig->isInvalidDecl() || UD->isInvalidDecl())
5977    Shadow->setInvalidDecl();
5978
5979  if (S)
5980    PushOnScopeChains(Shadow, S);
5981  else
5982    CurContext->addDecl(Shadow);
5983
5984
5985  return Shadow;
5986}
5987
5988/// Hides a using shadow declaration.  This is required by the current
5989/// using-decl implementation when a resolvable using declaration in a
5990/// class is followed by a declaration which would hide or override
5991/// one or more of the using decl's targets; for example:
5992///
5993///   struct Base { void foo(int); };
5994///   struct Derived : Base {
5995///     using Base::foo;
5996///     void foo(int);
5997///   };
5998///
5999/// The governing language is C++03 [namespace.udecl]p12:
6000///
6001///   When a using-declaration brings names from a base class into a
6002///   derived class scope, member functions in the derived class
6003///   override and/or hide member functions with the same name and
6004///   parameter types in a base class (rather than conflicting).
6005///
6006/// There are two ways to implement this:
6007///   (1) optimistically create shadow decls when they're not hidden
6008///       by existing declarations, or
6009///   (2) don't create any shadow decls (or at least don't make them
6010///       visible) until we've fully parsed/instantiated the class.
6011/// The problem with (1) is that we might have to retroactively remove
6012/// a shadow decl, which requires several O(n) operations because the
6013/// decl structures are (very reasonably) not designed for removal.
6014/// (2) avoids this but is very fiddly and phase-dependent.
6015void Sema::HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow) {
6016  if (Shadow->getDeclName().getNameKind() ==
6017        DeclarationName::CXXConversionFunctionName)
6018    cast<CXXRecordDecl>(Shadow->getDeclContext())->removeConversion(Shadow);
6019
6020  // Remove it from the DeclContext...
6021  Shadow->getDeclContext()->removeDecl(Shadow);
6022
6023  // ...and the scope, if applicable...
6024  if (S) {
6025    S->RemoveDecl(Shadow);
6026    IdResolver.RemoveDecl(Shadow);
6027  }
6028
6029  // ...and the using decl.
6030  Shadow->getUsingDecl()->removeShadowDecl(Shadow);
6031
6032  // TODO: complain somehow if Shadow was used.  It shouldn't
6033  // be possible for this to happen, because...?
6034}
6035
6036/// Builds a using declaration.
6037///
6038/// \param IsInstantiation - Whether this call arises from an
6039///   instantiation of an unresolved using declaration.  We treat
6040///   the lookup differently for these declarations.
6041NamedDecl *Sema::BuildUsingDeclaration(Scope *S, AccessSpecifier AS,
6042                                       SourceLocation UsingLoc,
6043                                       CXXScopeSpec &SS,
6044                                       const DeclarationNameInfo &NameInfo,
6045                                       AttributeList *AttrList,
6046                                       bool IsInstantiation,
6047                                       bool IsTypeName,
6048                                       SourceLocation TypenameLoc) {
6049  assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
6050  SourceLocation IdentLoc = NameInfo.getLoc();
6051  assert(IdentLoc.isValid() && "Invalid TargetName location.");
6052
6053  // FIXME: We ignore attributes for now.
6054
6055  if (SS.isEmpty()) {
6056    Diag(IdentLoc, diag::err_using_requires_qualname);
6057    return 0;
6058  }
6059
6060  // Do the redeclaration lookup in the current scope.
6061  LookupResult Previous(*this, NameInfo, LookupUsingDeclName,
6062                        ForRedeclaration);
6063  Previous.setHideTags(false);
6064  if (S) {
6065    LookupName(Previous, S);
6066
6067    // It is really dumb that we have to do this.
6068    LookupResult::Filter F = Previous.makeFilter();
6069    while (F.hasNext()) {
6070      NamedDecl *D = F.next();
6071      if (!isDeclInScope(D, CurContext, S))
6072        F.erase();
6073    }
6074    F.done();
6075  } else {
6076    assert(IsInstantiation && "no scope in non-instantiation");
6077    assert(CurContext->isRecord() && "scope not record in instantiation");
6078    LookupQualifiedName(Previous, CurContext);
6079  }
6080
6081  // Check for invalid redeclarations.
6082  if (CheckUsingDeclRedeclaration(UsingLoc, IsTypeName, SS, IdentLoc, Previous))
6083    return 0;
6084
6085  // Check for bad qualifiers.
6086  if (CheckUsingDeclQualifier(UsingLoc, SS, IdentLoc))
6087    return 0;
6088
6089  DeclContext *LookupContext = computeDeclContext(SS);
6090  NamedDecl *D;
6091  NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
6092  if (!LookupContext) {
6093    if (IsTypeName) {
6094      // FIXME: not all declaration name kinds are legal here
6095      D = UnresolvedUsingTypenameDecl::Create(Context, CurContext,
6096                                              UsingLoc, TypenameLoc,
6097                                              QualifierLoc,
6098                                              IdentLoc, NameInfo.getName());
6099    } else {
6100      D = UnresolvedUsingValueDecl::Create(Context, CurContext, UsingLoc,
6101                                           QualifierLoc, NameInfo);
6102    }
6103  } else {
6104    D = UsingDecl::Create(Context, CurContext, UsingLoc, QualifierLoc,
6105                          NameInfo, IsTypeName);
6106  }
6107  D->setAccess(AS);
6108  CurContext->addDecl(D);
6109
6110  if (!LookupContext) return D;
6111  UsingDecl *UD = cast<UsingDecl>(D);
6112
6113  if (RequireCompleteDeclContext(SS, LookupContext)) {
6114    UD->setInvalidDecl();
6115    return UD;
6116  }
6117
6118  // The normal rules do not apply to inheriting constructor declarations.
6119  if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName) {
6120    if (CheckInheritingConstructorUsingDecl(UD))
6121      UD->setInvalidDecl();
6122    return UD;
6123  }
6124
6125  // Otherwise, look up the target name.
6126
6127  LookupResult R(*this, NameInfo, LookupOrdinaryName);
6128
6129  // Unlike most lookups, we don't always want to hide tag
6130  // declarations: tag names are visible through the using declaration
6131  // even if hidden by ordinary names, *except* in a dependent context
6132  // where it's important for the sanity of two-phase lookup.
6133  if (!IsInstantiation)
6134    R.setHideTags(false);
6135
6136  // For the purposes of this lookup, we have a base object type
6137  // equal to that of the current context.
6138  if (CurContext->isRecord()) {
6139    R.setBaseObjectType(
6140                   Context.getTypeDeclType(cast<CXXRecordDecl>(CurContext)));
6141  }
6142
6143  LookupQualifiedName(R, LookupContext);
6144
6145  if (R.empty()) {
6146    Diag(IdentLoc, diag::err_no_member)
6147      << NameInfo.getName() << LookupContext << SS.getRange();
6148    UD->setInvalidDecl();
6149    return UD;
6150  }
6151
6152  if (R.isAmbiguous()) {
6153    UD->setInvalidDecl();
6154    return UD;
6155  }
6156
6157  if (IsTypeName) {
6158    // If we asked for a typename and got a non-type decl, error out.
6159    if (!R.getAsSingle<TypeDecl>()) {
6160      Diag(IdentLoc, diag::err_using_typename_non_type);
6161      for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
6162        Diag((*I)->getUnderlyingDecl()->getLocation(),
6163             diag::note_using_decl_target);
6164      UD->setInvalidDecl();
6165      return UD;
6166    }
6167  } else {
6168    // If we asked for a non-typename and we got a type, error out,
6169    // but only if this is an instantiation of an unresolved using
6170    // decl.  Otherwise just silently find the type name.
6171    if (IsInstantiation && R.getAsSingle<TypeDecl>()) {
6172      Diag(IdentLoc, diag::err_using_dependent_value_is_type);
6173      Diag(R.getFoundDecl()->getLocation(), diag::note_using_decl_target);
6174      UD->setInvalidDecl();
6175      return UD;
6176    }
6177  }
6178
6179  // C++0x N2914 [namespace.udecl]p6:
6180  // A using-declaration shall not name a namespace.
6181  if (R.getAsSingle<NamespaceDecl>()) {
6182    Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace)
6183      << SS.getRange();
6184    UD->setInvalidDecl();
6185    return UD;
6186  }
6187
6188  for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
6189    if (!CheckUsingShadowDecl(UD, *I, Previous))
6190      BuildUsingShadowDecl(S, UD, *I);
6191  }
6192
6193  return UD;
6194}
6195
6196/// Additional checks for a using declaration referring to a constructor name.
6197bool Sema::CheckInheritingConstructorUsingDecl(UsingDecl *UD) {
6198  assert(!UD->isTypeName() && "expecting a constructor name");
6199
6200  const Type *SourceType = UD->getQualifier()->getAsType();
6201  assert(SourceType &&
6202         "Using decl naming constructor doesn't have type in scope spec.");
6203  CXXRecordDecl *TargetClass = cast<CXXRecordDecl>(CurContext);
6204
6205  // Check whether the named type is a direct base class.
6206  CanQualType CanonicalSourceType = SourceType->getCanonicalTypeUnqualified();
6207  CXXRecordDecl::base_class_iterator BaseIt, BaseE;
6208  for (BaseIt = TargetClass->bases_begin(), BaseE = TargetClass->bases_end();
6209       BaseIt != BaseE; ++BaseIt) {
6210    CanQualType BaseType = BaseIt->getType()->getCanonicalTypeUnqualified();
6211    if (CanonicalSourceType == BaseType)
6212      break;
6213    if (BaseIt->getType()->isDependentType())
6214      break;
6215  }
6216
6217  if (BaseIt == BaseE) {
6218    // Did not find SourceType in the bases.
6219    Diag(UD->getUsingLocation(),
6220         diag::err_using_decl_constructor_not_in_direct_base)
6221      << UD->getNameInfo().getSourceRange()
6222      << QualType(SourceType, 0) << TargetClass;
6223    return true;
6224  }
6225
6226  if (!CurContext->isDependentContext())
6227    BaseIt->setInheritConstructors();
6228
6229  return false;
6230}
6231
6232/// Checks that the given using declaration is not an invalid
6233/// redeclaration.  Note that this is checking only for the using decl
6234/// itself, not for any ill-formedness among the UsingShadowDecls.
6235bool Sema::CheckUsingDeclRedeclaration(SourceLocation UsingLoc,
6236                                       bool isTypeName,
6237                                       const CXXScopeSpec &SS,
6238                                       SourceLocation NameLoc,
6239                                       const LookupResult &Prev) {
6240  // C++03 [namespace.udecl]p8:
6241  // C++0x [namespace.udecl]p10:
6242  //   A using-declaration is a declaration and can therefore be used
6243  //   repeatedly where (and only where) multiple declarations are
6244  //   allowed.
6245  //
6246  // That's in non-member contexts.
6247  if (!CurContext->getRedeclContext()->isRecord())
6248    return false;
6249
6250  NestedNameSpecifier *Qual
6251    = static_cast<NestedNameSpecifier*>(SS.getScopeRep());
6252
6253  for (LookupResult::iterator I = Prev.begin(), E = Prev.end(); I != E; ++I) {
6254    NamedDecl *D = *I;
6255
6256    bool DTypename;
6257    NestedNameSpecifier *DQual;
6258    if (UsingDecl *UD = dyn_cast<UsingDecl>(D)) {
6259      DTypename = UD->isTypeName();
6260      DQual = UD->getQualifier();
6261    } else if (UnresolvedUsingValueDecl *UD
6262                 = dyn_cast<UnresolvedUsingValueDecl>(D)) {
6263      DTypename = false;
6264      DQual = UD->getQualifier();
6265    } else if (UnresolvedUsingTypenameDecl *UD
6266                 = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
6267      DTypename = true;
6268      DQual = UD->getQualifier();
6269    } else continue;
6270
6271    // using decls differ if one says 'typename' and the other doesn't.
6272    // FIXME: non-dependent using decls?
6273    if (isTypeName != DTypename) continue;
6274
6275    // using decls differ if they name different scopes (but note that
6276    // template instantiation can cause this check to trigger when it
6277    // didn't before instantiation).
6278    if (Context.getCanonicalNestedNameSpecifier(Qual) !=
6279        Context.getCanonicalNestedNameSpecifier(DQual))
6280      continue;
6281
6282    Diag(NameLoc, diag::err_using_decl_redeclaration) << SS.getRange();
6283    Diag(D->getLocation(), diag::note_using_decl) << 1;
6284    return true;
6285  }
6286
6287  return false;
6288}
6289
6290
6291/// Checks that the given nested-name qualifier used in a using decl
6292/// in the current context is appropriately related to the current
6293/// scope.  If an error is found, diagnoses it and returns true.
6294bool Sema::CheckUsingDeclQualifier(SourceLocation UsingLoc,
6295                                   const CXXScopeSpec &SS,
6296                                   SourceLocation NameLoc) {
6297  DeclContext *NamedContext = computeDeclContext(SS);
6298
6299  if (!CurContext->isRecord()) {
6300    // C++03 [namespace.udecl]p3:
6301    // C++0x [namespace.udecl]p8:
6302    //   A using-declaration for a class member shall be a member-declaration.
6303
6304    // If we weren't able to compute a valid scope, it must be a
6305    // dependent class scope.
6306    if (!NamedContext || NamedContext->isRecord()) {
6307      Diag(NameLoc, diag::err_using_decl_can_not_refer_to_class_member)
6308        << SS.getRange();
6309      return true;
6310    }
6311
6312    // Otherwise, everything is known to be fine.
6313    return false;
6314  }
6315
6316  // The current scope is a record.
6317
6318  // If the named context is dependent, we can't decide much.
6319  if (!NamedContext) {
6320    // FIXME: in C++0x, we can diagnose if we can prove that the
6321    // nested-name-specifier does not refer to a base class, which is
6322    // still possible in some cases.
6323
6324    // Otherwise we have to conservatively report that things might be
6325    // okay.
6326    return false;
6327  }
6328
6329  if (!NamedContext->isRecord()) {
6330    // Ideally this would point at the last name in the specifier,
6331    // but we don't have that level of source info.
6332    Diag(SS.getRange().getBegin(),
6333         diag::err_using_decl_nested_name_specifier_is_not_class)
6334      << (NestedNameSpecifier*) SS.getScopeRep() << SS.getRange();
6335    return true;
6336  }
6337
6338  if (!NamedContext->isDependentContext() &&
6339      RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), NamedContext))
6340    return true;
6341
6342  if (getLangOpts().CPlusPlus0x) {
6343    // C++0x [namespace.udecl]p3:
6344    //   In a using-declaration used as a member-declaration, the
6345    //   nested-name-specifier shall name a base class of the class
6346    //   being defined.
6347
6348    if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(
6349                                 cast<CXXRecordDecl>(NamedContext))) {
6350      if (CurContext == NamedContext) {
6351        Diag(NameLoc,
6352             diag::err_using_decl_nested_name_specifier_is_current_class)
6353          << SS.getRange();
6354        return true;
6355      }
6356
6357      Diag(SS.getRange().getBegin(),
6358           diag::err_using_decl_nested_name_specifier_is_not_base_class)
6359        << (NestedNameSpecifier*) SS.getScopeRep()
6360        << cast<CXXRecordDecl>(CurContext)
6361        << SS.getRange();
6362      return true;
6363    }
6364
6365    return false;
6366  }
6367
6368  // C++03 [namespace.udecl]p4:
6369  //   A using-declaration used as a member-declaration shall refer
6370  //   to a member of a base class of the class being defined [etc.].
6371
6372  // Salient point: SS doesn't have to name a base class as long as
6373  // lookup only finds members from base classes.  Therefore we can
6374  // diagnose here only if we can prove that that can't happen,
6375  // i.e. if the class hierarchies provably don't intersect.
6376
6377  // TODO: it would be nice if "definitely valid" results were cached
6378  // in the UsingDecl and UsingShadowDecl so that these checks didn't
6379  // need to be repeated.
6380
6381  struct UserData {
6382    llvm::SmallPtrSet<const CXXRecordDecl*, 4> Bases;
6383
6384    static bool collect(const CXXRecordDecl *Base, void *OpaqueData) {
6385      UserData *Data = reinterpret_cast<UserData*>(OpaqueData);
6386      Data->Bases.insert(Base);
6387      return true;
6388    }
6389
6390    bool hasDependentBases(const CXXRecordDecl *Class) {
6391      return !Class->forallBases(collect, this);
6392    }
6393
6394    /// Returns true if the base is dependent or is one of the
6395    /// accumulated base classes.
6396    static bool doesNotContain(const CXXRecordDecl *Base, void *OpaqueData) {
6397      UserData *Data = reinterpret_cast<UserData*>(OpaqueData);
6398      return !Data->Bases.count(Base);
6399    }
6400
6401    bool mightShareBases(const CXXRecordDecl *Class) {
6402      return Bases.count(Class) || !Class->forallBases(doesNotContain, this);
6403    }
6404  };
6405
6406  UserData Data;
6407
6408  // Returns false if we find a dependent base.
6409  if (Data.hasDependentBases(cast<CXXRecordDecl>(CurContext)))
6410    return false;
6411
6412  // Returns false if the class has a dependent base or if it or one
6413  // of its bases is present in the base set of the current context.
6414  if (Data.mightShareBases(cast<CXXRecordDecl>(NamedContext)))
6415    return false;
6416
6417  Diag(SS.getRange().getBegin(),
6418       diag::err_using_decl_nested_name_specifier_is_not_base_class)
6419    << (NestedNameSpecifier*) SS.getScopeRep()
6420    << cast<CXXRecordDecl>(CurContext)
6421    << SS.getRange();
6422
6423  return true;
6424}
6425
6426Decl *Sema::ActOnAliasDeclaration(Scope *S,
6427                                  AccessSpecifier AS,
6428                                  MultiTemplateParamsArg TemplateParamLists,
6429                                  SourceLocation UsingLoc,
6430                                  UnqualifiedId &Name,
6431                                  TypeResult Type) {
6432  // Skip up to the relevant declaration scope.
6433  while (S->getFlags() & Scope::TemplateParamScope)
6434    S = S->getParent();
6435  assert((S->getFlags() & Scope::DeclScope) &&
6436         "got alias-declaration outside of declaration scope");
6437
6438  if (Type.isInvalid())
6439    return 0;
6440
6441  bool Invalid = false;
6442  DeclarationNameInfo NameInfo = GetNameFromUnqualifiedId(Name);
6443  TypeSourceInfo *TInfo = 0;
6444  GetTypeFromParser(Type.get(), &TInfo);
6445
6446  if (DiagnoseClassNameShadow(CurContext, NameInfo))
6447    return 0;
6448
6449  if (DiagnoseUnexpandedParameterPack(Name.StartLocation, TInfo,
6450                                      UPPC_DeclarationType)) {
6451    Invalid = true;
6452    TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
6453                                             TInfo->getTypeLoc().getBeginLoc());
6454  }
6455
6456  LookupResult Previous(*this, NameInfo, LookupOrdinaryName, ForRedeclaration);
6457  LookupName(Previous, S);
6458
6459  // Warn about shadowing the name of a template parameter.
6460  if (Previous.isSingleResult() &&
6461      Previous.getFoundDecl()->isTemplateParameter()) {
6462    DiagnoseTemplateParameterShadow(Name.StartLocation,Previous.getFoundDecl());
6463    Previous.clear();
6464  }
6465
6466  assert(Name.Kind == UnqualifiedId::IK_Identifier &&
6467         "name in alias declaration must be an identifier");
6468  TypeAliasDecl *NewTD = TypeAliasDecl::Create(Context, CurContext, UsingLoc,
6469                                               Name.StartLocation,
6470                                               Name.Identifier, TInfo);
6471
6472  NewTD->setAccess(AS);
6473
6474  if (Invalid)
6475    NewTD->setInvalidDecl();
6476
6477  CheckTypedefForVariablyModifiedType(S, NewTD);
6478  Invalid |= NewTD->isInvalidDecl();
6479
6480  bool Redeclaration = false;
6481
6482  NamedDecl *NewND;
6483  if (TemplateParamLists.size()) {
6484    TypeAliasTemplateDecl *OldDecl = 0;
6485    TemplateParameterList *OldTemplateParams = 0;
6486
6487    if (TemplateParamLists.size() != 1) {
6488      Diag(UsingLoc, diag::err_alias_template_extra_headers)
6489        << SourceRange(TemplateParamLists.get()[1]->getTemplateLoc(),
6490         TemplateParamLists.get()[TemplateParamLists.size()-1]->getRAngleLoc());
6491    }
6492    TemplateParameterList *TemplateParams = TemplateParamLists.get()[0];
6493
6494    // Only consider previous declarations in the same scope.
6495    FilterLookupForScope(Previous, CurContext, S, /*ConsiderLinkage*/false,
6496                         /*ExplicitInstantiationOrSpecialization*/false);
6497    if (!Previous.empty()) {
6498      Redeclaration = true;
6499
6500      OldDecl = Previous.getAsSingle<TypeAliasTemplateDecl>();
6501      if (!OldDecl && !Invalid) {
6502        Diag(UsingLoc, diag::err_redefinition_different_kind)
6503          << Name.Identifier;
6504
6505        NamedDecl *OldD = Previous.getRepresentativeDecl();
6506        if (OldD->getLocation().isValid())
6507          Diag(OldD->getLocation(), diag::note_previous_definition);
6508
6509        Invalid = true;
6510      }
6511
6512      if (!Invalid && OldDecl && !OldDecl->isInvalidDecl()) {
6513        if (TemplateParameterListsAreEqual(TemplateParams,
6514                                           OldDecl->getTemplateParameters(),
6515                                           /*Complain=*/true,
6516                                           TPL_TemplateMatch))
6517          OldTemplateParams = OldDecl->getTemplateParameters();
6518        else
6519          Invalid = true;
6520
6521        TypeAliasDecl *OldTD = OldDecl->getTemplatedDecl();
6522        if (!Invalid &&
6523            !Context.hasSameType(OldTD->getUnderlyingType(),
6524                                 NewTD->getUnderlyingType())) {
6525          // FIXME: The C++0x standard does not clearly say this is ill-formed,
6526          // but we can't reasonably accept it.
6527          Diag(NewTD->getLocation(), diag::err_redefinition_different_typedef)
6528            << 2 << NewTD->getUnderlyingType() << OldTD->getUnderlyingType();
6529          if (OldTD->getLocation().isValid())
6530            Diag(OldTD->getLocation(), diag::note_previous_definition);
6531          Invalid = true;
6532        }
6533      }
6534    }
6535
6536    // Merge any previous default template arguments into our parameters,
6537    // and check the parameter list.
6538    if (CheckTemplateParameterList(TemplateParams, OldTemplateParams,
6539                                   TPC_TypeAliasTemplate))
6540      return 0;
6541
6542    TypeAliasTemplateDecl *NewDecl =
6543      TypeAliasTemplateDecl::Create(Context, CurContext, UsingLoc,
6544                                    Name.Identifier, TemplateParams,
6545                                    NewTD);
6546
6547    NewDecl->setAccess(AS);
6548
6549    if (Invalid)
6550      NewDecl->setInvalidDecl();
6551    else if (OldDecl)
6552      NewDecl->setPreviousDeclaration(OldDecl);
6553
6554    NewND = NewDecl;
6555  } else {
6556    ActOnTypedefNameDecl(S, CurContext, NewTD, Previous, Redeclaration);
6557    NewND = NewTD;
6558  }
6559
6560  if (!Redeclaration)
6561    PushOnScopeChains(NewND, S);
6562
6563  return NewND;
6564}
6565
6566Decl *Sema::ActOnNamespaceAliasDef(Scope *S,
6567                                             SourceLocation NamespaceLoc,
6568                                             SourceLocation AliasLoc,
6569                                             IdentifierInfo *Alias,
6570                                             CXXScopeSpec &SS,
6571                                             SourceLocation IdentLoc,
6572                                             IdentifierInfo *Ident) {
6573
6574  // Lookup the namespace name.
6575  LookupResult R(*this, Ident, IdentLoc, LookupNamespaceName);
6576  LookupParsedName(R, S, &SS);
6577
6578  // Check if we have a previous declaration with the same name.
6579  NamedDecl *PrevDecl
6580    = LookupSingleName(S, Alias, AliasLoc, LookupOrdinaryName,
6581                       ForRedeclaration);
6582  if (PrevDecl && !isDeclInScope(PrevDecl, CurContext, S))
6583    PrevDecl = 0;
6584
6585  if (PrevDecl) {
6586    if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) {
6587      // We already have an alias with the same name that points to the same
6588      // namespace, so don't create a new one.
6589      // FIXME: At some point, we'll want to create the (redundant)
6590      // declaration to maintain better source information.
6591      if (!R.isAmbiguous() && !R.empty() &&
6592          AD->getNamespace()->Equals(getNamespaceDecl(R.getFoundDecl())))
6593        return 0;
6594    }
6595
6596    unsigned DiagID = isa<NamespaceDecl>(PrevDecl) ? diag::err_redefinition :
6597      diag::err_redefinition_different_kind;
6598    Diag(AliasLoc, DiagID) << Alias;
6599    Diag(PrevDecl->getLocation(), diag::note_previous_definition);
6600    return 0;
6601  }
6602
6603  if (R.isAmbiguous())
6604    return 0;
6605
6606  if (R.empty()) {
6607    if (!TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, Ident)) {
6608      Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
6609      return 0;
6610    }
6611  }
6612
6613  NamespaceAliasDecl *AliasDecl =
6614    NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc,
6615                               Alias, SS.getWithLocInContext(Context),
6616                               IdentLoc, R.getFoundDecl());
6617
6618  PushOnScopeChains(AliasDecl, S);
6619  return AliasDecl;
6620}
6621
6622namespace {
6623  /// \brief Scoped object used to handle the state changes required in Sema
6624  /// to implicitly define the body of a C++ member function;
6625  class ImplicitlyDefinedFunctionScope {
6626    Sema &S;
6627    Sema::ContextRAII SavedContext;
6628
6629  public:
6630    ImplicitlyDefinedFunctionScope(Sema &S, CXXMethodDecl *Method)
6631      : S(S), SavedContext(S, Method)
6632    {
6633      S.PushFunctionScope();
6634      S.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
6635    }
6636
6637    ~ImplicitlyDefinedFunctionScope() {
6638      S.PopExpressionEvaluationContext();
6639      S.PopFunctionScopeInfo();
6640    }
6641  };
6642}
6643
6644Sema::ImplicitExceptionSpecification
6645Sema::ComputeDefaultedDefaultCtorExceptionSpec(CXXRecordDecl *ClassDecl) {
6646  // C++ [except.spec]p14:
6647  //   An implicitly declared special member function (Clause 12) shall have an
6648  //   exception-specification. [...]
6649  ImplicitExceptionSpecification ExceptSpec(*this);
6650  if (ClassDecl->isInvalidDecl())
6651    return ExceptSpec;
6652
6653  // Direct base-class constructors.
6654  for (CXXRecordDecl::base_class_iterator B = ClassDecl->bases_begin(),
6655                                       BEnd = ClassDecl->bases_end();
6656       B != BEnd; ++B) {
6657    if (B->isVirtual()) // Handled below.
6658      continue;
6659
6660    if (const RecordType *BaseType = B->getType()->getAs<RecordType>()) {
6661      CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
6662      CXXConstructorDecl *Constructor = LookupDefaultConstructor(BaseClassDecl);
6663      // If this is a deleted function, add it anyway. This might be conformant
6664      // with the standard. This might not. I'm not sure. It might not matter.
6665      if (Constructor)
6666        ExceptSpec.CalledDecl(B->getLocStart(), Constructor);
6667    }
6668  }
6669
6670  // Virtual base-class constructors.
6671  for (CXXRecordDecl::base_class_iterator B = ClassDecl->vbases_begin(),
6672                                       BEnd = ClassDecl->vbases_end();
6673       B != BEnd; ++B) {
6674    if (const RecordType *BaseType = B->getType()->getAs<RecordType>()) {
6675      CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
6676      CXXConstructorDecl *Constructor = LookupDefaultConstructor(BaseClassDecl);
6677      // If this is a deleted function, add it anyway. This might be conformant
6678      // with the standard. This might not. I'm not sure. It might not matter.
6679      if (Constructor)
6680        ExceptSpec.CalledDecl(B->getLocStart(), Constructor);
6681    }
6682  }
6683
6684  // Field constructors.
6685  for (RecordDecl::field_iterator F = ClassDecl->field_begin(),
6686                               FEnd = ClassDecl->field_end();
6687       F != FEnd; ++F) {
6688    if (F->hasInClassInitializer()) {
6689      if (Expr *E = F->getInClassInitializer())
6690        ExceptSpec.CalledExpr(E);
6691      else if (!F->isInvalidDecl())
6692        ExceptSpec.SetDelayed();
6693    } else if (const RecordType *RecordTy
6694              = Context.getBaseElementType(F->getType())->getAs<RecordType>()) {
6695      CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
6696      CXXConstructorDecl *Constructor = LookupDefaultConstructor(FieldRecDecl);
6697      // If this is a deleted function, add it anyway. This might be conformant
6698      // with the standard. This might not. I'm not sure. It might not matter.
6699      // In particular, the problem is that this function never gets called. It
6700      // might just be ill-formed because this function attempts to refer to
6701      // a deleted function here.
6702      if (Constructor)
6703        ExceptSpec.CalledDecl(F->getLocation(), Constructor);
6704    }
6705  }
6706
6707  return ExceptSpec;
6708}
6709
6710CXXConstructorDecl *Sema::DeclareImplicitDefaultConstructor(
6711                                                     CXXRecordDecl *ClassDecl) {
6712  // C++ [class.ctor]p5:
6713  //   A default constructor for a class X is a constructor of class X
6714  //   that can be called without an argument. If there is no
6715  //   user-declared constructor for class X, a default constructor is
6716  //   implicitly declared. An implicitly-declared default constructor
6717  //   is an inline public member of its class.
6718  assert(!ClassDecl->hasUserDeclaredConstructor() &&
6719         "Should not build implicit default constructor!");
6720
6721  ImplicitExceptionSpecification Spec =
6722    ComputeDefaultedDefaultCtorExceptionSpec(ClassDecl);
6723  FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
6724
6725  bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
6726                                                     CXXDefaultConstructor,
6727                                                     false);
6728
6729  // Create the actual constructor declaration.
6730  CanQualType ClassType
6731    = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
6732  SourceLocation ClassLoc = ClassDecl->getLocation();
6733  DeclarationName Name
6734    = Context.DeclarationNames.getCXXConstructorName(ClassType);
6735  DeclarationNameInfo NameInfo(Name, ClassLoc);
6736  CXXConstructorDecl *DefaultCon = CXXConstructorDecl::Create(
6737      Context, ClassDecl, ClassLoc, NameInfo,
6738      Context.getFunctionType(Context.VoidTy, 0, 0, EPI), /*TInfo=*/0,
6739      /*isExplicit=*/false, /*isInline=*/true, /*isImplicitlyDeclared=*/true,
6740      Constexpr);
6741  DefaultCon->setAccess(AS_public);
6742  DefaultCon->setDefaulted();
6743  DefaultCon->setImplicit();
6744  DefaultCon->setTrivial(ClassDecl->hasTrivialDefaultConstructor());
6745
6746  // Note that we have declared this constructor.
6747  ++ASTContext::NumImplicitDefaultConstructorsDeclared;
6748
6749  if (Scope *S = getScopeForContext(ClassDecl))
6750    PushOnScopeChains(DefaultCon, S, false);
6751  ClassDecl->addDecl(DefaultCon);
6752
6753  if (ShouldDeleteSpecialMember(DefaultCon, CXXDefaultConstructor))
6754    DefaultCon->setDeletedAsWritten();
6755
6756  return DefaultCon;
6757}
6758
6759void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
6760                                            CXXConstructorDecl *Constructor) {
6761  assert((Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&
6762          !Constructor->doesThisDeclarationHaveABody() &&
6763          !Constructor->isDeleted()) &&
6764    "DefineImplicitDefaultConstructor - call it for implicit default ctor");
6765
6766  CXXRecordDecl *ClassDecl = Constructor->getParent();
6767  assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor");
6768
6769  ImplicitlyDefinedFunctionScope Scope(*this, Constructor);
6770  DiagnosticErrorTrap Trap(Diags);
6771  if (SetCtorInitializers(Constructor, 0, 0, /*AnyErrors=*/false) ||
6772      Trap.hasErrorOccurred()) {
6773    Diag(CurrentLocation, diag::note_member_synthesized_at)
6774      << CXXDefaultConstructor << Context.getTagDeclType(ClassDecl);
6775    Constructor->setInvalidDecl();
6776    return;
6777  }
6778
6779  SourceLocation Loc = Constructor->getLocation();
6780  Constructor->setBody(new (Context) CompoundStmt(Context, 0, 0, Loc, Loc));
6781
6782  Constructor->setUsed();
6783  MarkVTableUsed(CurrentLocation, ClassDecl);
6784
6785  if (ASTMutationListener *L = getASTMutationListener()) {
6786    L->CompletedImplicitDefinition(Constructor);
6787  }
6788}
6789
6790/// Get any existing defaulted default constructor for the given class. Do not
6791/// implicitly define one if it does not exist.
6792static CXXConstructorDecl *getDefaultedDefaultConstructorUnsafe(Sema &Self,
6793                                                             CXXRecordDecl *D) {
6794  ASTContext &Context = Self.Context;
6795  QualType ClassType = Context.getTypeDeclType(D);
6796  DeclarationName ConstructorName
6797    = Context.DeclarationNames.getCXXConstructorName(
6798                      Context.getCanonicalType(ClassType.getUnqualifiedType()));
6799
6800  DeclContext::lookup_const_iterator Con, ConEnd;
6801  for (llvm::tie(Con, ConEnd) = D->lookup(ConstructorName);
6802       Con != ConEnd; ++Con) {
6803    // A function template cannot be defaulted.
6804    if (isa<FunctionTemplateDecl>(*Con))
6805      continue;
6806
6807    CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con);
6808    if (Constructor->isDefaultConstructor())
6809      return Constructor->isDefaulted() ? Constructor : 0;
6810  }
6811  return 0;
6812}
6813
6814void Sema::ActOnFinishDelayedMemberInitializers(Decl *D) {
6815  if (!D) return;
6816  AdjustDeclIfTemplate(D);
6817
6818  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(D);
6819  CXXConstructorDecl *CtorDecl
6820    = getDefaultedDefaultConstructorUnsafe(*this, ClassDecl);
6821
6822  if (!CtorDecl) return;
6823
6824  // Compute the exception specification for the default constructor.
6825  const FunctionProtoType *CtorTy =
6826    CtorDecl->getType()->castAs<FunctionProtoType>();
6827  if (CtorTy->getExceptionSpecType() == EST_Delayed) {
6828    // FIXME: Don't do this unless the exception spec is needed.
6829    ImplicitExceptionSpecification Spec =
6830      ComputeDefaultedDefaultCtorExceptionSpec(ClassDecl);
6831    FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
6832    assert(EPI.ExceptionSpecType != EST_Delayed);
6833
6834    CtorDecl->setType(Context.getFunctionType(Context.VoidTy, 0, 0, EPI));
6835  }
6836
6837  // If the default constructor is explicitly defaulted, checking the exception
6838  // specification is deferred until now.
6839  if (!CtorDecl->isInvalidDecl() && CtorDecl->isExplicitlyDefaulted() &&
6840      !ClassDecl->isDependentType())
6841    CheckExplicitlyDefaultedSpecialMember(CtorDecl);
6842}
6843
6844void Sema::DeclareInheritedConstructors(CXXRecordDecl *ClassDecl) {
6845  // We start with an initial pass over the base classes to collect those that
6846  // inherit constructors from. If there are none, we can forgo all further
6847  // processing.
6848  typedef SmallVector<const RecordType *, 4> BasesVector;
6849  BasesVector BasesToInheritFrom;
6850  for (CXXRecordDecl::base_class_iterator BaseIt = ClassDecl->bases_begin(),
6851                                          BaseE = ClassDecl->bases_end();
6852         BaseIt != BaseE; ++BaseIt) {
6853    if (BaseIt->getInheritConstructors()) {
6854      QualType Base = BaseIt->getType();
6855      if (Base->isDependentType()) {
6856        // If we inherit constructors from anything that is dependent, just
6857        // abort processing altogether. We'll get another chance for the
6858        // instantiations.
6859        return;
6860      }
6861      BasesToInheritFrom.push_back(Base->castAs<RecordType>());
6862    }
6863  }
6864  if (BasesToInheritFrom.empty())
6865    return;
6866
6867  // Now collect the constructors that we already have in the current class.
6868  // Those take precedence over inherited constructors.
6869  // C++0x [class.inhctor]p3: [...] a constructor is implicitly declared [...]
6870  //   unless there is a user-declared constructor with the same signature in
6871  //   the class where the using-declaration appears.
6872  llvm::SmallSet<const Type *, 8> ExistingConstructors;
6873  for (CXXRecordDecl::ctor_iterator CtorIt = ClassDecl->ctor_begin(),
6874                                    CtorE = ClassDecl->ctor_end();
6875       CtorIt != CtorE; ++CtorIt) {
6876    ExistingConstructors.insert(
6877        Context.getCanonicalType(CtorIt->getType()).getTypePtr());
6878  }
6879
6880  DeclarationName CreatedCtorName =
6881      Context.DeclarationNames.getCXXConstructorName(
6882          ClassDecl->getTypeForDecl()->getCanonicalTypeUnqualified());
6883
6884  // Now comes the true work.
6885  // First, we keep a map from constructor types to the base that introduced
6886  // them. Needed for finding conflicting constructors. We also keep the
6887  // actually inserted declarations in there, for pretty diagnostics.
6888  typedef std::pair<CanQualType, CXXConstructorDecl *> ConstructorInfo;
6889  typedef llvm::DenseMap<const Type *, ConstructorInfo> ConstructorToSourceMap;
6890  ConstructorToSourceMap InheritedConstructors;
6891  for (BasesVector::iterator BaseIt = BasesToInheritFrom.begin(),
6892                             BaseE = BasesToInheritFrom.end();
6893       BaseIt != BaseE; ++BaseIt) {
6894    const RecordType *Base = *BaseIt;
6895    CanQualType CanonicalBase = Base->getCanonicalTypeUnqualified();
6896    CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(Base->getDecl());
6897    for (CXXRecordDecl::ctor_iterator CtorIt = BaseDecl->ctor_begin(),
6898                                      CtorE = BaseDecl->ctor_end();
6899         CtorIt != CtorE; ++CtorIt) {
6900      // Find the using declaration for inheriting this base's constructors.
6901      // FIXME: Don't perform name lookup just to obtain a source location!
6902      DeclarationName Name =
6903          Context.DeclarationNames.getCXXConstructorName(CanonicalBase);
6904      LookupResult Result(*this, Name, SourceLocation(), LookupUsingDeclName);
6905      LookupQualifiedName(Result, CurContext);
6906      UsingDecl *UD = Result.getAsSingle<UsingDecl>();
6907      SourceLocation UsingLoc = UD ? UD->getLocation() :
6908                                     ClassDecl->getLocation();
6909
6910      // C++0x [class.inhctor]p1: The candidate set of inherited constructors
6911      //   from the class X named in the using-declaration consists of actual
6912      //   constructors and notional constructors that result from the
6913      //   transformation of defaulted parameters as follows:
6914      //   - all non-template default constructors of X, and
6915      //   - for each non-template constructor of X that has at least one
6916      //     parameter with a default argument, the set of constructors that
6917      //     results from omitting any ellipsis parameter specification and
6918      //     successively omitting parameters with a default argument from the
6919      //     end of the parameter-type-list.
6920      CXXConstructorDecl *BaseCtor = *CtorIt;
6921      bool CanBeCopyOrMove = BaseCtor->isCopyOrMoveConstructor();
6922      const FunctionProtoType *BaseCtorType =
6923          BaseCtor->getType()->getAs<FunctionProtoType>();
6924
6925      for (unsigned params = BaseCtor->getMinRequiredArguments(),
6926                    maxParams = BaseCtor->getNumParams();
6927           params <= maxParams; ++params) {
6928        // Skip default constructors. They're never inherited.
6929        if (params == 0)
6930          continue;
6931        // Skip copy and move constructors for the same reason.
6932        if (CanBeCopyOrMove && params == 1)
6933          continue;
6934
6935        // Build up a function type for this particular constructor.
6936        // FIXME: The working paper does not consider that the exception spec
6937        // for the inheriting constructor might be larger than that of the
6938        // source. This code doesn't yet, either. When it does, this code will
6939        // need to be delayed until after exception specifications and in-class
6940        // member initializers are attached.
6941        const Type *NewCtorType;
6942        if (params == maxParams)
6943          NewCtorType = BaseCtorType;
6944        else {
6945          SmallVector<QualType, 16> Args;
6946          for (unsigned i = 0; i < params; ++i) {
6947            Args.push_back(BaseCtorType->getArgType(i));
6948          }
6949          FunctionProtoType::ExtProtoInfo ExtInfo =
6950              BaseCtorType->getExtProtoInfo();
6951          ExtInfo.Variadic = false;
6952          NewCtorType = Context.getFunctionType(BaseCtorType->getResultType(),
6953                                                Args.data(), params, ExtInfo)
6954                       .getTypePtr();
6955        }
6956        const Type *CanonicalNewCtorType =
6957            Context.getCanonicalType(NewCtorType);
6958
6959        // Now that we have the type, first check if the class already has a
6960        // constructor with this signature.
6961        if (ExistingConstructors.count(CanonicalNewCtorType))
6962          continue;
6963
6964        // Then we check if we have already declared an inherited constructor
6965        // with this signature.
6966        std::pair<ConstructorToSourceMap::iterator, bool> result =
6967            InheritedConstructors.insert(std::make_pair(
6968                CanonicalNewCtorType,
6969                std::make_pair(CanonicalBase, (CXXConstructorDecl*)0)));
6970        if (!result.second) {
6971          // Already in the map. If it came from a different class, that's an
6972          // error. Not if it's from the same.
6973          CanQualType PreviousBase = result.first->second.first;
6974          if (CanonicalBase != PreviousBase) {
6975            const CXXConstructorDecl *PrevCtor = result.first->second.second;
6976            const CXXConstructorDecl *PrevBaseCtor =
6977                PrevCtor->getInheritedConstructor();
6978            assert(PrevBaseCtor && "Conflicting constructor was not inherited");
6979
6980            Diag(UsingLoc, diag::err_using_decl_constructor_conflict);
6981            Diag(BaseCtor->getLocation(),
6982                 diag::note_using_decl_constructor_conflict_current_ctor);
6983            Diag(PrevBaseCtor->getLocation(),
6984                 diag::note_using_decl_constructor_conflict_previous_ctor);
6985            Diag(PrevCtor->getLocation(),
6986                 diag::note_using_decl_constructor_conflict_previous_using);
6987          }
6988          continue;
6989        }
6990
6991        // OK, we're there, now add the constructor.
6992        // C++0x [class.inhctor]p8: [...] that would be performed by a
6993        //   user-written inline constructor [...]
6994        DeclarationNameInfo DNI(CreatedCtorName, UsingLoc);
6995        CXXConstructorDecl *NewCtor = CXXConstructorDecl::Create(
6996            Context, ClassDecl, UsingLoc, DNI, QualType(NewCtorType, 0),
6997            /*TInfo=*/0, BaseCtor->isExplicit(), /*Inline=*/true,
6998            /*ImplicitlyDeclared=*/true,
6999            // FIXME: Due to a defect in the standard, we treat inherited
7000            // constructors as constexpr even if that makes them ill-formed.
7001            /*Constexpr=*/BaseCtor->isConstexpr());
7002        NewCtor->setAccess(BaseCtor->getAccess());
7003
7004        // Build up the parameter decls and add them.
7005        SmallVector<ParmVarDecl *, 16> ParamDecls;
7006        for (unsigned i = 0; i < params; ++i) {
7007          ParamDecls.push_back(ParmVarDecl::Create(Context, NewCtor,
7008                                                   UsingLoc, UsingLoc,
7009                                                   /*IdentifierInfo=*/0,
7010                                                   BaseCtorType->getArgType(i),
7011                                                   /*TInfo=*/0, SC_None,
7012                                                   SC_None, /*DefaultArg=*/0));
7013        }
7014        NewCtor->setParams(ParamDecls);
7015        NewCtor->setInheritedConstructor(BaseCtor);
7016
7017        ClassDecl->addDecl(NewCtor);
7018        result.first->second.second = NewCtor;
7019      }
7020    }
7021  }
7022}
7023
7024Sema::ImplicitExceptionSpecification
7025Sema::ComputeDefaultedDtorExceptionSpec(CXXRecordDecl *ClassDecl) {
7026  // C++ [except.spec]p14:
7027  //   An implicitly declared special member function (Clause 12) shall have
7028  //   an exception-specification.
7029  ImplicitExceptionSpecification ExceptSpec(*this);
7030  if (ClassDecl->isInvalidDecl())
7031    return ExceptSpec;
7032
7033  // Direct base-class destructors.
7034  for (CXXRecordDecl::base_class_iterator B = ClassDecl->bases_begin(),
7035                                       BEnd = ClassDecl->bases_end();
7036       B != BEnd; ++B) {
7037    if (B->isVirtual()) // Handled below.
7038      continue;
7039
7040    if (const RecordType *BaseType = B->getType()->getAs<RecordType>())
7041      ExceptSpec.CalledDecl(B->getLocStart(),
7042                   LookupDestructor(cast<CXXRecordDecl>(BaseType->getDecl())));
7043  }
7044
7045  // Virtual base-class destructors.
7046  for (CXXRecordDecl::base_class_iterator B = ClassDecl->vbases_begin(),
7047                                       BEnd = ClassDecl->vbases_end();
7048       B != BEnd; ++B) {
7049    if (const RecordType *BaseType = B->getType()->getAs<RecordType>())
7050      ExceptSpec.CalledDecl(B->getLocStart(),
7051                  LookupDestructor(cast<CXXRecordDecl>(BaseType->getDecl())));
7052  }
7053
7054  // Field destructors.
7055  for (RecordDecl::field_iterator F = ClassDecl->field_begin(),
7056                               FEnd = ClassDecl->field_end();
7057       F != FEnd; ++F) {
7058    if (const RecordType *RecordTy
7059        = Context.getBaseElementType(F->getType())->getAs<RecordType>())
7060      ExceptSpec.CalledDecl(F->getLocation(),
7061                  LookupDestructor(cast<CXXRecordDecl>(RecordTy->getDecl())));
7062  }
7063
7064  return ExceptSpec;
7065}
7066
7067CXXDestructorDecl *Sema::DeclareImplicitDestructor(CXXRecordDecl *ClassDecl) {
7068  // C++ [class.dtor]p2:
7069  //   If a class has no user-declared destructor, a destructor is
7070  //   declared implicitly. An implicitly-declared destructor is an
7071  //   inline public member of its class.
7072
7073  ImplicitExceptionSpecification Spec =
7074      ComputeDefaultedDtorExceptionSpec(ClassDecl);
7075  FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
7076
7077  // Create the actual destructor declaration.
7078  QualType Ty = Context.getFunctionType(Context.VoidTy, 0, 0, EPI);
7079
7080  CanQualType ClassType
7081    = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
7082  SourceLocation ClassLoc = ClassDecl->getLocation();
7083  DeclarationName Name
7084    = Context.DeclarationNames.getCXXDestructorName(ClassType);
7085  DeclarationNameInfo NameInfo(Name, ClassLoc);
7086  CXXDestructorDecl *Destructor
7087      = CXXDestructorDecl::Create(Context, ClassDecl, ClassLoc, NameInfo, Ty, 0,
7088                                  /*isInline=*/true,
7089                                  /*isImplicitlyDeclared=*/true);
7090  Destructor->setAccess(AS_public);
7091  Destructor->setDefaulted();
7092  Destructor->setImplicit();
7093  Destructor->setTrivial(ClassDecl->hasTrivialDestructor());
7094
7095  // Note that we have declared this destructor.
7096  ++ASTContext::NumImplicitDestructorsDeclared;
7097
7098  // Introduce this destructor into its scope.
7099  if (Scope *S = getScopeForContext(ClassDecl))
7100    PushOnScopeChains(Destructor, S, false);
7101  ClassDecl->addDecl(Destructor);
7102
7103  // This could be uniqued if it ever proves significant.
7104  Destructor->setTypeSourceInfo(Context.getTrivialTypeSourceInfo(Ty));
7105
7106  AddOverriddenMethods(ClassDecl, Destructor);
7107
7108  if (ShouldDeleteSpecialMember(Destructor, CXXDestructor))
7109    Destructor->setDeletedAsWritten();
7110
7111  return Destructor;
7112}
7113
7114void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation,
7115                                    CXXDestructorDecl *Destructor) {
7116  assert((Destructor->isDefaulted() &&
7117          !Destructor->doesThisDeclarationHaveABody() &&
7118          !Destructor->isDeleted()) &&
7119         "DefineImplicitDestructor - call it for implicit default dtor");
7120  CXXRecordDecl *ClassDecl = Destructor->getParent();
7121  assert(ClassDecl && "DefineImplicitDestructor - invalid destructor");
7122
7123  if (Destructor->isInvalidDecl())
7124    return;
7125
7126  ImplicitlyDefinedFunctionScope Scope(*this, Destructor);
7127
7128  DiagnosticErrorTrap Trap(Diags);
7129  MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(),
7130                                         Destructor->getParent());
7131
7132  if (CheckDestructor(Destructor) || Trap.hasErrorOccurred()) {
7133    Diag(CurrentLocation, diag::note_member_synthesized_at)
7134      << CXXDestructor << Context.getTagDeclType(ClassDecl);
7135
7136    Destructor->setInvalidDecl();
7137    return;
7138  }
7139
7140  SourceLocation Loc = Destructor->getLocation();
7141  Destructor->setBody(new (Context) CompoundStmt(Context, 0, 0, Loc, Loc));
7142  Destructor->setImplicitlyDefined(true);
7143  Destructor->setUsed();
7144  MarkVTableUsed(CurrentLocation, ClassDecl);
7145
7146  if (ASTMutationListener *L = getASTMutationListener()) {
7147    L->CompletedImplicitDefinition(Destructor);
7148  }
7149}
7150
7151/// \brief Perform any semantic analysis which needs to be delayed until all
7152/// pending class member declarations have been parsed.
7153void Sema::ActOnFinishCXXMemberDecls() {
7154  // Now we have parsed all exception specifications, determine the implicit
7155  // exception specifications for destructors.
7156  for (unsigned i = 0, e = DelayedDestructorExceptionSpecs.size();
7157       i != e; ++i) {
7158    CXXDestructorDecl *Dtor = DelayedDestructorExceptionSpecs[i];
7159    AdjustDestructorExceptionSpec(Dtor->getParent(), Dtor, true);
7160  }
7161  DelayedDestructorExceptionSpecs.clear();
7162
7163  // Perform any deferred checking of exception specifications for virtual
7164  // destructors.
7165  for (unsigned i = 0, e = DelayedDestructorExceptionSpecChecks.size();
7166       i != e; ++i) {
7167    const CXXDestructorDecl *Dtor =
7168        DelayedDestructorExceptionSpecChecks[i].first;
7169    assert(!Dtor->getParent()->isDependentType() &&
7170           "Should not ever add destructors of templates into the list.");
7171    CheckOverridingFunctionExceptionSpec(Dtor,
7172        DelayedDestructorExceptionSpecChecks[i].second);
7173  }
7174  DelayedDestructorExceptionSpecChecks.clear();
7175}
7176
7177void Sema::AdjustDestructorExceptionSpec(CXXRecordDecl *classDecl,
7178                                         CXXDestructorDecl *destructor,
7179                                         bool WasDelayed) {
7180  // C++11 [class.dtor]p3:
7181  //   A declaration of a destructor that does not have an exception-
7182  //   specification is implicitly considered to have the same exception-
7183  //   specification as an implicit declaration.
7184  const FunctionProtoType *dtorType = destructor->getType()->
7185                                        getAs<FunctionProtoType>();
7186  if (!WasDelayed && dtorType->hasExceptionSpec())
7187    return;
7188
7189  ImplicitExceptionSpecification exceptSpec =
7190      ComputeDefaultedDtorExceptionSpec(classDecl);
7191
7192  // Replace the destructor's type, building off the existing one. Fortunately,
7193  // the only thing of interest in the destructor type is its extended info.
7194  // The return and arguments are fixed.
7195  FunctionProtoType::ExtProtoInfo epi = dtorType->getExtProtoInfo();
7196  epi.ExceptionSpecType = exceptSpec.getExceptionSpecType();
7197  epi.NumExceptions = exceptSpec.size();
7198  epi.Exceptions = exceptSpec.data();
7199  QualType ty = Context.getFunctionType(Context.VoidTy, 0, 0, epi);
7200
7201  destructor->setType(ty);
7202
7203  // If we can't compute the exception specification for this destructor yet
7204  // (because it depends on an exception specification which we have not parsed
7205  // yet), make a note that we need to try again when the class is complete.
7206  if (epi.ExceptionSpecType == EST_Delayed) {
7207    assert(!WasDelayed && "couldn't compute destructor exception spec");
7208    DelayedDestructorExceptionSpecs.push_back(destructor);
7209  }
7210
7211  // FIXME: If the destructor has a body that could throw, and the newly created
7212  // spec doesn't allow exceptions, we should emit a warning, because this
7213  // change in behavior can break conforming C++03 programs at runtime.
7214  // However, we don't have a body yet, so it needs to be done somewhere else.
7215}
7216
7217/// \brief Builds a statement that copies/moves the given entity from \p From to
7218/// \c To.
7219///
7220/// This routine is used to copy/move the members of a class with an
7221/// implicitly-declared copy/move assignment operator. When the entities being
7222/// copied are arrays, this routine builds for loops to copy them.
7223///
7224/// \param S The Sema object used for type-checking.
7225///
7226/// \param Loc The location where the implicit copy/move is being generated.
7227///
7228/// \param T The type of the expressions being copied/moved. Both expressions
7229/// must have this type.
7230///
7231/// \param To The expression we are copying/moving to.
7232///
7233/// \param From The expression we are copying/moving from.
7234///
7235/// \param CopyingBaseSubobject Whether we're copying/moving a base subobject.
7236/// Otherwise, it's a non-static member subobject.
7237///
7238/// \param Copying Whether we're copying or moving.
7239///
7240/// \param Depth Internal parameter recording the depth of the recursion.
7241///
7242/// \returns A statement or a loop that copies the expressions.
7243static StmtResult
7244BuildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T,
7245                      Expr *To, Expr *From,
7246                      bool CopyingBaseSubobject, bool Copying,
7247                      unsigned Depth = 0) {
7248  // C++0x [class.copy]p28:
7249  //   Each subobject is assigned in the manner appropriate to its type:
7250  //
7251  //     - if the subobject is of class type, as if by a call to operator= with
7252  //       the subobject as the object expression and the corresponding
7253  //       subobject of x as a single function argument (as if by explicit
7254  //       qualification; that is, ignoring any possible virtual overriding
7255  //       functions in more derived classes);
7256  if (const RecordType *RecordTy = T->getAs<RecordType>()) {
7257    CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
7258
7259    // Look for operator=.
7260    DeclarationName Name
7261      = S.Context.DeclarationNames.getCXXOperatorName(OO_Equal);
7262    LookupResult OpLookup(S, Name, Loc, Sema::LookupOrdinaryName);
7263    S.LookupQualifiedName(OpLookup, ClassDecl, false);
7264
7265    // Filter out any result that isn't a copy/move-assignment operator.
7266    LookupResult::Filter F = OpLookup.makeFilter();
7267    while (F.hasNext()) {
7268      NamedDecl *D = F.next();
7269      if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
7270        if (Method->isCopyAssignmentOperator() ||
7271            (!Copying && Method->isMoveAssignmentOperator()))
7272          continue;
7273
7274      F.erase();
7275    }
7276    F.done();
7277
7278    // Suppress the protected check (C++ [class.protected]) for each of the
7279    // assignment operators we found. This strange dance is required when
7280    // we're assigning via a base classes's copy-assignment operator. To
7281    // ensure that we're getting the right base class subobject (without
7282    // ambiguities), we need to cast "this" to that subobject type; to
7283    // ensure that we don't go through the virtual call mechanism, we need
7284    // to qualify the operator= name with the base class (see below). However,
7285    // this means that if the base class has a protected copy assignment
7286    // operator, the protected member access check will fail. So, we
7287    // rewrite "protected" access to "public" access in this case, since we
7288    // know by construction that we're calling from a derived class.
7289    if (CopyingBaseSubobject) {
7290      for (LookupResult::iterator L = OpLookup.begin(), LEnd = OpLookup.end();
7291           L != LEnd; ++L) {
7292        if (L.getAccess() == AS_protected)
7293          L.setAccess(AS_public);
7294      }
7295    }
7296
7297    // Create the nested-name-specifier that will be used to qualify the
7298    // reference to operator=; this is required to suppress the virtual
7299    // call mechanism.
7300    CXXScopeSpec SS;
7301    const Type *CanonicalT = S.Context.getCanonicalType(T.getTypePtr());
7302    SS.MakeTrivial(S.Context,
7303                   NestedNameSpecifier::Create(S.Context, 0, false,
7304                                               CanonicalT),
7305                   Loc);
7306
7307    // Create the reference to operator=.
7308    ExprResult OpEqualRef
7309      = S.BuildMemberReferenceExpr(To, T, Loc, /*isArrow=*/false, SS,
7310                                   /*TemplateKWLoc=*/SourceLocation(),
7311                                   /*FirstQualifierInScope=*/0,
7312                                   OpLookup,
7313                                   /*TemplateArgs=*/0,
7314                                   /*SuppressQualifierCheck=*/true);
7315    if (OpEqualRef.isInvalid())
7316      return StmtError();
7317
7318    // Build the call to the assignment operator.
7319
7320    ExprResult Call = S.BuildCallToMemberFunction(/*Scope=*/0,
7321                                                  OpEqualRef.takeAs<Expr>(),
7322                                                  Loc, &From, 1, Loc);
7323    if (Call.isInvalid())
7324      return StmtError();
7325
7326    return S.Owned(Call.takeAs<Stmt>());
7327  }
7328
7329  //     - if the subobject is of scalar type, the built-in assignment
7330  //       operator is used.
7331  const ConstantArrayType *ArrayTy = S.Context.getAsConstantArrayType(T);
7332  if (!ArrayTy) {
7333    ExprResult Assignment = S.CreateBuiltinBinOp(Loc, BO_Assign, To, From);
7334    if (Assignment.isInvalid())
7335      return StmtError();
7336
7337    return S.Owned(Assignment.takeAs<Stmt>());
7338  }
7339
7340  //     - if the subobject is an array, each element is assigned, in the
7341  //       manner appropriate to the element type;
7342
7343  // Construct a loop over the array bounds, e.g.,
7344  //
7345  //   for (__SIZE_TYPE__ i0 = 0; i0 != array-size; ++i0)
7346  //
7347  // that will copy each of the array elements.
7348  QualType SizeType = S.Context.getSizeType();
7349
7350  // Create the iteration variable.
7351  IdentifierInfo *IterationVarName = 0;
7352  {
7353    SmallString<8> Str;
7354    llvm::raw_svector_ostream OS(Str);
7355    OS << "__i" << Depth;
7356    IterationVarName = &S.Context.Idents.get(OS.str());
7357  }
7358  VarDecl *IterationVar = VarDecl::Create(S.Context, S.CurContext, Loc, Loc,
7359                                          IterationVarName, SizeType,
7360                            S.Context.getTrivialTypeSourceInfo(SizeType, Loc),
7361                                          SC_None, SC_None);
7362
7363  // Initialize the iteration variable to zero.
7364  llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0);
7365  IterationVar->setInit(IntegerLiteral::Create(S.Context, Zero, SizeType, Loc));
7366
7367  // Create a reference to the iteration variable; we'll use this several
7368  // times throughout.
7369  Expr *IterationVarRef
7370    = S.BuildDeclRefExpr(IterationVar, SizeType, VK_LValue, Loc).take();
7371  assert(IterationVarRef && "Reference to invented variable cannot fail!");
7372  Expr *IterationVarRefRVal = S.DefaultLvalueConversion(IterationVarRef).take();
7373  assert(IterationVarRefRVal && "Conversion of invented variable cannot fail!");
7374
7375  // Create the DeclStmt that holds the iteration variable.
7376  Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(IterationVar),Loc,Loc);
7377
7378  // Create the comparison against the array bound.
7379  llvm::APInt Upper
7380    = ArrayTy->getSize().zextOrTrunc(S.Context.getTypeSize(SizeType));
7381  Expr *Comparison
7382    = new (S.Context) BinaryOperator(IterationVarRefRVal,
7383                     IntegerLiteral::Create(S.Context, Upper, SizeType, Loc),
7384                                     BO_NE, S.Context.BoolTy,
7385                                     VK_RValue, OK_Ordinary, Loc);
7386
7387  // Create the pre-increment of the iteration variable.
7388  Expr *Increment
7389    = new (S.Context) UnaryOperator(IterationVarRef, UO_PreInc, SizeType,
7390                                    VK_LValue, OK_Ordinary, Loc);
7391
7392  // Subscript the "from" and "to" expressions with the iteration variable.
7393  From = AssertSuccess(S.CreateBuiltinArraySubscriptExpr(From, Loc,
7394                                                         IterationVarRefRVal,
7395                                                         Loc));
7396  To = AssertSuccess(S.CreateBuiltinArraySubscriptExpr(To, Loc,
7397                                                       IterationVarRefRVal,
7398                                                       Loc));
7399  if (!Copying) // Cast to rvalue
7400    From = CastForMoving(S, From);
7401
7402  // Build the copy/move for an individual element of the array.
7403  StmtResult Copy = BuildSingleCopyAssign(S, Loc, ArrayTy->getElementType(),
7404                                          To, From, CopyingBaseSubobject,
7405                                          Copying, Depth + 1);
7406  if (Copy.isInvalid())
7407    return StmtError();
7408
7409  // Construct the loop that copies all elements of this array.
7410  return S.ActOnForStmt(Loc, Loc, InitStmt,
7411                        S.MakeFullExpr(Comparison),
7412                        0, S.MakeFullExpr(Increment),
7413                        Loc, Copy.take());
7414}
7415
7416std::pair<Sema::ImplicitExceptionSpecification, bool>
7417Sema::ComputeDefaultedCopyAssignmentExceptionSpecAndConst(
7418                                                   CXXRecordDecl *ClassDecl) {
7419  if (ClassDecl->isInvalidDecl())
7420    return std::make_pair(ImplicitExceptionSpecification(*this), true);
7421
7422  // C++ [class.copy]p10:
7423  //   If the class definition does not explicitly declare a copy
7424  //   assignment operator, one is declared implicitly.
7425  //   The implicitly-defined copy assignment operator for a class X
7426  //   will have the form
7427  //
7428  //       X& X::operator=(const X&)
7429  //
7430  //   if
7431  bool HasConstCopyAssignment = true;
7432
7433  //       -- each direct base class B of X has a copy assignment operator
7434  //          whose parameter is of type const B&, const volatile B& or B,
7435  //          and
7436  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
7437                                       BaseEnd = ClassDecl->bases_end();
7438       HasConstCopyAssignment && Base != BaseEnd; ++Base) {
7439    // We'll handle this below
7440    if (LangOpts.CPlusPlus0x && Base->isVirtual())
7441      continue;
7442
7443    assert(!Base->getType()->isDependentType() &&
7444           "Cannot generate implicit members for class with dependent bases.");
7445    CXXRecordDecl *BaseClassDecl = Base->getType()->getAsCXXRecordDecl();
7446    HasConstCopyAssignment &=
7447      (bool)LookupCopyingAssignment(BaseClassDecl, Qualifiers::Const,
7448                                    false, 0);
7449  }
7450
7451  // In C++11, the above citation has "or virtual" added
7452  if (LangOpts.CPlusPlus0x) {
7453    for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
7454                                         BaseEnd = ClassDecl->vbases_end();
7455         HasConstCopyAssignment && Base != BaseEnd; ++Base) {
7456      assert(!Base->getType()->isDependentType() &&
7457             "Cannot generate implicit members for class with dependent bases.");
7458      CXXRecordDecl *BaseClassDecl = Base->getType()->getAsCXXRecordDecl();
7459      HasConstCopyAssignment &=
7460        (bool)LookupCopyingAssignment(BaseClassDecl, Qualifiers::Const,
7461                                      false, 0);
7462    }
7463  }
7464
7465  //       -- for all the nonstatic data members of X that are of a class
7466  //          type M (or array thereof), each such class type has a copy
7467  //          assignment operator whose parameter is of type const M&,
7468  //          const volatile M& or M.
7469  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
7470                                  FieldEnd = ClassDecl->field_end();
7471       HasConstCopyAssignment && Field != FieldEnd;
7472       ++Field) {
7473    QualType FieldType = Context.getBaseElementType(Field->getType());
7474    if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) {
7475      HasConstCopyAssignment &=
7476        (bool)LookupCopyingAssignment(FieldClassDecl, Qualifiers::Const,
7477                                      false, 0);
7478    }
7479  }
7480
7481  //   Otherwise, the implicitly declared copy assignment operator will
7482  //   have the form
7483  //
7484  //       X& X::operator=(X&)
7485
7486  // C++ [except.spec]p14:
7487  //   An implicitly declared special member function (Clause 12) shall have an
7488  //   exception-specification. [...]
7489
7490  // It is unspecified whether or not an implicit copy assignment operator
7491  // attempts to deduplicate calls to assignment operators of virtual bases are
7492  // made. As such, this exception specification is effectively unspecified.
7493  // Based on a similar decision made for constness in C++0x, we're erring on
7494  // the side of assuming such calls to be made regardless of whether they
7495  // actually happen.
7496  ImplicitExceptionSpecification ExceptSpec(*this);
7497  unsigned ArgQuals = HasConstCopyAssignment ? Qualifiers::Const : 0;
7498  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
7499                                       BaseEnd = ClassDecl->bases_end();
7500       Base != BaseEnd; ++Base) {
7501    if (Base->isVirtual())
7502      continue;
7503
7504    CXXRecordDecl *BaseClassDecl
7505      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
7506    if (CXXMethodDecl *CopyAssign = LookupCopyingAssignment(BaseClassDecl,
7507                                                            ArgQuals, false, 0))
7508      ExceptSpec.CalledDecl(Base->getLocStart(), CopyAssign);
7509  }
7510
7511  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
7512                                       BaseEnd = ClassDecl->vbases_end();
7513       Base != BaseEnd; ++Base) {
7514    CXXRecordDecl *BaseClassDecl
7515      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
7516    if (CXXMethodDecl *CopyAssign = LookupCopyingAssignment(BaseClassDecl,
7517                                                            ArgQuals, false, 0))
7518      ExceptSpec.CalledDecl(Base->getLocStart(), CopyAssign);
7519  }
7520
7521  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
7522                                  FieldEnd = ClassDecl->field_end();
7523       Field != FieldEnd;
7524       ++Field) {
7525    QualType FieldType = Context.getBaseElementType(Field->getType());
7526    if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) {
7527      if (CXXMethodDecl *CopyAssign =
7528          LookupCopyingAssignment(FieldClassDecl, ArgQuals, false, 0))
7529        ExceptSpec.CalledDecl(Field->getLocation(), CopyAssign);
7530    }
7531  }
7532
7533  return std::make_pair(ExceptSpec, HasConstCopyAssignment);
7534}
7535
7536CXXMethodDecl *Sema::DeclareImplicitCopyAssignment(CXXRecordDecl *ClassDecl) {
7537  // Note: The following rules are largely analoguous to the copy
7538  // constructor rules. Note that virtual bases are not taken into account
7539  // for determining the argument type of the operator. Note also that
7540  // operators taking an object instead of a reference are allowed.
7541
7542  ImplicitExceptionSpecification Spec(*this);
7543  bool Const;
7544  llvm::tie(Spec, Const) =
7545    ComputeDefaultedCopyAssignmentExceptionSpecAndConst(ClassDecl);
7546
7547  QualType ArgType = Context.getTypeDeclType(ClassDecl);
7548  QualType RetType = Context.getLValueReferenceType(ArgType);
7549  if (Const)
7550    ArgType = ArgType.withConst();
7551  ArgType = Context.getLValueReferenceType(ArgType);
7552
7553  //   An implicitly-declared copy assignment operator is an inline public
7554  //   member of its class.
7555  FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
7556  DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
7557  SourceLocation ClassLoc = ClassDecl->getLocation();
7558  DeclarationNameInfo NameInfo(Name, ClassLoc);
7559  CXXMethodDecl *CopyAssignment
7560    = CXXMethodDecl::Create(Context, ClassDecl, ClassLoc, NameInfo,
7561                            Context.getFunctionType(RetType, &ArgType, 1, EPI),
7562                            /*TInfo=*/0, /*isStatic=*/false,
7563                            /*StorageClassAsWritten=*/SC_None,
7564                            /*isInline=*/true, /*isConstexpr=*/false,
7565                            SourceLocation());
7566  CopyAssignment->setAccess(AS_public);
7567  CopyAssignment->setDefaulted();
7568  CopyAssignment->setImplicit();
7569  CopyAssignment->setTrivial(ClassDecl->hasTrivialCopyAssignment());
7570
7571  // Add the parameter to the operator.
7572  ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment,
7573                                               ClassLoc, ClassLoc, /*Id=*/0,
7574                                               ArgType, /*TInfo=*/0,
7575                                               SC_None,
7576                                               SC_None, 0);
7577  CopyAssignment->setParams(FromParam);
7578
7579  // Note that we have added this copy-assignment operator.
7580  ++ASTContext::NumImplicitCopyAssignmentOperatorsDeclared;
7581
7582  if (Scope *S = getScopeForContext(ClassDecl))
7583    PushOnScopeChains(CopyAssignment, S, false);
7584  ClassDecl->addDecl(CopyAssignment);
7585
7586  // C++0x [class.copy]p19:
7587  //   ....  If the class definition does not explicitly declare a copy
7588  //   assignment operator, there is no user-declared move constructor, and
7589  //   there is no user-declared move assignment operator, a copy assignment
7590  //   operator is implicitly declared as defaulted.
7591  if (ShouldDeleteSpecialMember(CopyAssignment, CXXCopyAssignment))
7592    CopyAssignment->setDeletedAsWritten();
7593
7594  AddOverriddenMethods(ClassDecl, CopyAssignment);
7595  return CopyAssignment;
7596}
7597
7598void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
7599                                        CXXMethodDecl *CopyAssignOperator) {
7600  assert((CopyAssignOperator->isDefaulted() &&
7601          CopyAssignOperator->isOverloadedOperator() &&
7602          CopyAssignOperator->getOverloadedOperator() == OO_Equal &&
7603          !CopyAssignOperator->doesThisDeclarationHaveABody() &&
7604          !CopyAssignOperator->isDeleted()) &&
7605         "DefineImplicitCopyAssignment called for wrong function");
7606
7607  CXXRecordDecl *ClassDecl = CopyAssignOperator->getParent();
7608
7609  if (ClassDecl->isInvalidDecl() || CopyAssignOperator->isInvalidDecl()) {
7610    CopyAssignOperator->setInvalidDecl();
7611    return;
7612  }
7613
7614  CopyAssignOperator->setUsed();
7615
7616  ImplicitlyDefinedFunctionScope Scope(*this, CopyAssignOperator);
7617  DiagnosticErrorTrap Trap(Diags);
7618
7619  // C++0x [class.copy]p30:
7620  //   The implicitly-defined or explicitly-defaulted copy assignment operator
7621  //   for a non-union class X performs memberwise copy assignment of its
7622  //   subobjects. The direct base classes of X are assigned first, in the
7623  //   order of their declaration in the base-specifier-list, and then the
7624  //   immediate non-static data members of X are assigned, in the order in
7625  //   which they were declared in the class definition.
7626
7627  // The statements that form the synthesized function body.
7628  ASTOwningVector<Stmt*> Statements(*this);
7629
7630  // The parameter for the "other" object, which we are copying from.
7631  ParmVarDecl *Other = CopyAssignOperator->getParamDecl(0);
7632  Qualifiers OtherQuals = Other->getType().getQualifiers();
7633  QualType OtherRefType = Other->getType();
7634  if (const LValueReferenceType *OtherRef
7635                                = OtherRefType->getAs<LValueReferenceType>()) {
7636    OtherRefType = OtherRef->getPointeeType();
7637    OtherQuals = OtherRefType.getQualifiers();
7638  }
7639
7640  // Our location for everything implicitly-generated.
7641  SourceLocation Loc = CopyAssignOperator->getLocation();
7642
7643  // Construct a reference to the "other" object. We'll be using this
7644  // throughout the generated ASTs.
7645  Expr *OtherRef = BuildDeclRefExpr(Other, OtherRefType, VK_LValue, Loc).take();
7646  assert(OtherRef && "Reference to parameter cannot fail!");
7647
7648  // Construct the "this" pointer. We'll be using this throughout the generated
7649  // ASTs.
7650  Expr *This = ActOnCXXThis(Loc).takeAs<Expr>();
7651  assert(This && "Reference to this cannot fail!");
7652
7653  // Assign base classes.
7654  bool Invalid = false;
7655  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
7656       E = ClassDecl->bases_end(); Base != E; ++Base) {
7657    // Form the assignment:
7658    //   static_cast<Base*>(this)->Base::operator=(static_cast<Base&>(other));
7659    QualType BaseType = Base->getType().getUnqualifiedType();
7660    if (!BaseType->isRecordType()) {
7661      Invalid = true;
7662      continue;
7663    }
7664
7665    CXXCastPath BasePath;
7666    BasePath.push_back(Base);
7667
7668    // Construct the "from" expression, which is an implicit cast to the
7669    // appropriately-qualified base type.
7670    Expr *From = OtherRef;
7671    From = ImpCastExprToType(From, Context.getQualifiedType(BaseType, OtherQuals),
7672                             CK_UncheckedDerivedToBase,
7673                             VK_LValue, &BasePath).take();
7674
7675    // Dereference "this".
7676    ExprResult To = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
7677
7678    // Implicitly cast "this" to the appropriately-qualified base type.
7679    To = ImpCastExprToType(To.take(),
7680                           Context.getCVRQualifiedType(BaseType,
7681                                     CopyAssignOperator->getTypeQualifiers()),
7682                           CK_UncheckedDerivedToBase,
7683                           VK_LValue, &BasePath);
7684
7685    // Build the copy.
7686    StmtResult Copy = BuildSingleCopyAssign(*this, Loc, BaseType,
7687                                            To.get(), From,
7688                                            /*CopyingBaseSubobject=*/true,
7689                                            /*Copying=*/true);
7690    if (Copy.isInvalid()) {
7691      Diag(CurrentLocation, diag::note_member_synthesized_at)
7692        << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
7693      CopyAssignOperator->setInvalidDecl();
7694      return;
7695    }
7696
7697    // Success! Record the copy.
7698    Statements.push_back(Copy.takeAs<Expr>());
7699  }
7700
7701  // \brief Reference to the __builtin_memcpy function.
7702  Expr *BuiltinMemCpyRef = 0;
7703  // \brief Reference to the __builtin_objc_memmove_collectable function.
7704  Expr *CollectableMemCpyRef = 0;
7705
7706  // Assign non-static members.
7707  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
7708                                  FieldEnd = ClassDecl->field_end();
7709       Field != FieldEnd; ++Field) {
7710    if (Field->isUnnamedBitfield())
7711      continue;
7712
7713    // Check for members of reference type; we can't copy those.
7714    if (Field->getType()->isReferenceType()) {
7715      Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
7716        << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
7717      Diag(Field->getLocation(), diag::note_declared_at);
7718      Diag(CurrentLocation, diag::note_member_synthesized_at)
7719        << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
7720      Invalid = true;
7721      continue;
7722    }
7723
7724    // Check for members of const-qualified, non-class type.
7725    QualType BaseType = Context.getBaseElementType(Field->getType());
7726    if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
7727      Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
7728        << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
7729      Diag(Field->getLocation(), diag::note_declared_at);
7730      Diag(CurrentLocation, diag::note_member_synthesized_at)
7731        << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
7732      Invalid = true;
7733      continue;
7734    }
7735
7736    // Suppress assigning zero-width bitfields.
7737    if (Field->isBitField() && Field->getBitWidthValue(Context) == 0)
7738      continue;
7739
7740    QualType FieldType = Field->getType().getNonReferenceType();
7741    if (FieldType->isIncompleteArrayType()) {
7742      assert(ClassDecl->hasFlexibleArrayMember() &&
7743             "Incomplete array type is not valid");
7744      continue;
7745    }
7746
7747    // Build references to the field in the object we're copying from and to.
7748    CXXScopeSpec SS; // Intentionally empty
7749    LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
7750                              LookupMemberName);
7751    MemberLookup.addDecl(*Field);
7752    MemberLookup.resolveKind();
7753    ExprResult From = BuildMemberReferenceExpr(OtherRef, OtherRefType,
7754                                               Loc, /*IsArrow=*/false,
7755                                               SS, SourceLocation(), 0,
7756                                               MemberLookup, 0);
7757    ExprResult To = BuildMemberReferenceExpr(This, This->getType(),
7758                                             Loc, /*IsArrow=*/true,
7759                                             SS, SourceLocation(), 0,
7760                                             MemberLookup, 0);
7761    assert(!From.isInvalid() && "Implicit field reference cannot fail");
7762    assert(!To.isInvalid() && "Implicit field reference cannot fail");
7763
7764    // If the field should be copied with __builtin_memcpy rather than via
7765    // explicit assignments, do so. This optimization only applies for arrays
7766    // of scalars and arrays of class type with trivial copy-assignment
7767    // operators.
7768    if (FieldType->isArrayType() && !FieldType.isVolatileQualified()
7769        && BaseType.hasTrivialAssignment(Context, /*Copying=*/true)) {
7770      // Compute the size of the memory buffer to be copied.
7771      QualType SizeType = Context.getSizeType();
7772      llvm::APInt Size(Context.getTypeSize(SizeType),
7773                       Context.getTypeSizeInChars(BaseType).getQuantity());
7774      for (const ConstantArrayType *Array
7775              = Context.getAsConstantArrayType(FieldType);
7776           Array;
7777           Array = Context.getAsConstantArrayType(Array->getElementType())) {
7778        llvm::APInt ArraySize
7779          = Array->getSize().zextOrTrunc(Size.getBitWidth());
7780        Size *= ArraySize;
7781      }
7782
7783      // Take the address of the field references for "from" and "to".
7784      From = CreateBuiltinUnaryOp(Loc, UO_AddrOf, From.get());
7785      To = CreateBuiltinUnaryOp(Loc, UO_AddrOf, To.get());
7786
7787      bool NeedsCollectableMemCpy =
7788          (BaseType->isRecordType() &&
7789           BaseType->getAs<RecordType>()->getDecl()->hasObjectMember());
7790
7791      if (NeedsCollectableMemCpy) {
7792        if (!CollectableMemCpyRef) {
7793          // Create a reference to the __builtin_objc_memmove_collectable function.
7794          LookupResult R(*this,
7795                         &Context.Idents.get("__builtin_objc_memmove_collectable"),
7796                         Loc, LookupOrdinaryName);
7797          LookupName(R, TUScope, true);
7798
7799          FunctionDecl *CollectableMemCpy = R.getAsSingle<FunctionDecl>();
7800          if (!CollectableMemCpy) {
7801            // Something went horribly wrong earlier, and we will have
7802            // complained about it.
7803            Invalid = true;
7804            continue;
7805          }
7806
7807          CollectableMemCpyRef = BuildDeclRefExpr(CollectableMemCpy,
7808                                                  CollectableMemCpy->getType(),
7809                                                  VK_LValue, Loc, 0).take();
7810          assert(CollectableMemCpyRef && "Builtin reference cannot fail");
7811        }
7812      }
7813      // Create a reference to the __builtin_memcpy builtin function.
7814      else if (!BuiltinMemCpyRef) {
7815        LookupResult R(*this, &Context.Idents.get("__builtin_memcpy"), Loc,
7816                       LookupOrdinaryName);
7817        LookupName(R, TUScope, true);
7818
7819        FunctionDecl *BuiltinMemCpy = R.getAsSingle<FunctionDecl>();
7820        if (!BuiltinMemCpy) {
7821          // Something went horribly wrong earlier, and we will have complained
7822          // about it.
7823          Invalid = true;
7824          continue;
7825        }
7826
7827        BuiltinMemCpyRef = BuildDeclRefExpr(BuiltinMemCpy,
7828                                            BuiltinMemCpy->getType(),
7829                                            VK_LValue, Loc, 0).take();
7830        assert(BuiltinMemCpyRef && "Builtin reference cannot fail");
7831      }
7832
7833      ASTOwningVector<Expr*> CallArgs(*this);
7834      CallArgs.push_back(To.takeAs<Expr>());
7835      CallArgs.push_back(From.takeAs<Expr>());
7836      CallArgs.push_back(IntegerLiteral::Create(Context, Size, SizeType, Loc));
7837      ExprResult Call = ExprError();
7838      if (NeedsCollectableMemCpy)
7839        Call = ActOnCallExpr(/*Scope=*/0,
7840                             CollectableMemCpyRef,
7841                             Loc, move_arg(CallArgs),
7842                             Loc);
7843      else
7844        Call = ActOnCallExpr(/*Scope=*/0,
7845                             BuiltinMemCpyRef,
7846                             Loc, move_arg(CallArgs),
7847                             Loc);
7848
7849      assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!");
7850      Statements.push_back(Call.takeAs<Expr>());
7851      continue;
7852    }
7853
7854    // Build the copy of this field.
7855    StmtResult Copy = BuildSingleCopyAssign(*this, Loc, FieldType,
7856                                            To.get(), From.get(),
7857                                            /*CopyingBaseSubobject=*/false,
7858                                            /*Copying=*/true);
7859    if (Copy.isInvalid()) {
7860      Diag(CurrentLocation, diag::note_member_synthesized_at)
7861        << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
7862      CopyAssignOperator->setInvalidDecl();
7863      return;
7864    }
7865
7866    // Success! Record the copy.
7867    Statements.push_back(Copy.takeAs<Stmt>());
7868  }
7869
7870  if (!Invalid) {
7871    // Add a "return *this;"
7872    ExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
7873
7874    StmtResult Return = ActOnReturnStmt(Loc, ThisObj.get());
7875    if (Return.isInvalid())
7876      Invalid = true;
7877    else {
7878      Statements.push_back(Return.takeAs<Stmt>());
7879
7880      if (Trap.hasErrorOccurred()) {
7881        Diag(CurrentLocation, diag::note_member_synthesized_at)
7882          << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
7883        Invalid = true;
7884      }
7885    }
7886  }
7887
7888  if (Invalid) {
7889    CopyAssignOperator->setInvalidDecl();
7890    return;
7891  }
7892
7893  StmtResult Body;
7894  {
7895    CompoundScopeRAII CompoundScope(*this);
7896    Body = ActOnCompoundStmt(Loc, Loc, move_arg(Statements),
7897                             /*isStmtExpr=*/false);
7898    assert(!Body.isInvalid() && "Compound statement creation cannot fail");
7899  }
7900  CopyAssignOperator->setBody(Body.takeAs<Stmt>());
7901
7902  if (ASTMutationListener *L = getASTMutationListener()) {
7903    L->CompletedImplicitDefinition(CopyAssignOperator);
7904  }
7905}
7906
7907Sema::ImplicitExceptionSpecification
7908Sema::ComputeDefaultedMoveAssignmentExceptionSpec(CXXRecordDecl *ClassDecl) {
7909  ImplicitExceptionSpecification ExceptSpec(*this);
7910
7911  if (ClassDecl->isInvalidDecl())
7912    return ExceptSpec;
7913
7914  // C++0x [except.spec]p14:
7915  //   An implicitly declared special member function (Clause 12) shall have an
7916  //   exception-specification. [...]
7917
7918  // It is unspecified whether or not an implicit move assignment operator
7919  // attempts to deduplicate calls to assignment operators of virtual bases are
7920  // made. As such, this exception specification is effectively unspecified.
7921  // Based on a similar decision made for constness in C++0x, we're erring on
7922  // the side of assuming such calls to be made regardless of whether they
7923  // actually happen.
7924  // Note that a move constructor is not implicitly declared when there are
7925  // virtual bases, but it can still be user-declared and explicitly defaulted.
7926  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
7927                                       BaseEnd = ClassDecl->bases_end();
7928       Base != BaseEnd; ++Base) {
7929    if (Base->isVirtual())
7930      continue;
7931
7932    CXXRecordDecl *BaseClassDecl
7933      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
7934    if (CXXMethodDecl *MoveAssign = LookupMovingAssignment(BaseClassDecl,
7935                                                           false, 0))
7936      ExceptSpec.CalledDecl(Base->getLocStart(), MoveAssign);
7937  }
7938
7939  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
7940                                       BaseEnd = ClassDecl->vbases_end();
7941       Base != BaseEnd; ++Base) {
7942    CXXRecordDecl *BaseClassDecl
7943      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
7944    if (CXXMethodDecl *MoveAssign = LookupMovingAssignment(BaseClassDecl,
7945                                                           false, 0))
7946      ExceptSpec.CalledDecl(Base->getLocStart(), MoveAssign);
7947  }
7948
7949  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
7950                                  FieldEnd = ClassDecl->field_end();
7951       Field != FieldEnd;
7952       ++Field) {
7953    QualType FieldType = Context.getBaseElementType(Field->getType());
7954    if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) {
7955      if (CXXMethodDecl *MoveAssign = LookupMovingAssignment(FieldClassDecl,
7956                                                             false, 0))
7957        ExceptSpec.CalledDecl(Field->getLocation(), MoveAssign);
7958    }
7959  }
7960
7961  return ExceptSpec;
7962}
7963
7964/// Determine whether the class type has any direct or indirect virtual base
7965/// classes which have a non-trivial move assignment operator.
7966static bool
7967hasVirtualBaseWithNonTrivialMoveAssignment(Sema &S, CXXRecordDecl *ClassDecl) {
7968  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
7969                                          BaseEnd = ClassDecl->vbases_end();
7970       Base != BaseEnd; ++Base) {
7971    CXXRecordDecl *BaseClass =
7972        cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
7973
7974    // Try to declare the move assignment. If it would be deleted, then the
7975    // class does not have a non-trivial move assignment.
7976    if (BaseClass->needsImplicitMoveAssignment())
7977      S.DeclareImplicitMoveAssignment(BaseClass);
7978
7979    // If the class has both a trivial move assignment and a non-trivial move
7980    // assignment, hasTrivialMoveAssignment() is false.
7981    if (BaseClass->hasDeclaredMoveAssignment() &&
7982        !BaseClass->hasTrivialMoveAssignment())
7983      return true;
7984  }
7985
7986  return false;
7987}
7988
7989/// Determine whether the given type either has a move constructor or is
7990/// trivially copyable.
7991static bool
7992hasMoveOrIsTriviallyCopyable(Sema &S, QualType Type, bool IsConstructor) {
7993  Type = S.Context.getBaseElementType(Type);
7994
7995  // FIXME: Technically, non-trivially-copyable non-class types, such as
7996  // reference types, are supposed to return false here, but that appears
7997  // to be a standard defect.
7998  CXXRecordDecl *ClassDecl = Type->getAsCXXRecordDecl();
7999  if (!ClassDecl || !ClassDecl->getDefinition())
8000    return true;
8001
8002  if (Type.isTriviallyCopyableType(S.Context))
8003    return true;
8004
8005  if (IsConstructor) {
8006    if (ClassDecl->needsImplicitMoveConstructor())
8007      S.DeclareImplicitMoveConstructor(ClassDecl);
8008    return ClassDecl->hasDeclaredMoveConstructor();
8009  }
8010
8011  if (ClassDecl->needsImplicitMoveAssignment())
8012    S.DeclareImplicitMoveAssignment(ClassDecl);
8013  return ClassDecl->hasDeclaredMoveAssignment();
8014}
8015
8016/// Determine whether all non-static data members and direct or virtual bases
8017/// of class \p ClassDecl have either a move operation, or are trivially
8018/// copyable.
8019static bool subobjectsHaveMoveOrTrivialCopy(Sema &S, CXXRecordDecl *ClassDecl,
8020                                            bool IsConstructor) {
8021  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
8022                                          BaseEnd = ClassDecl->bases_end();
8023       Base != BaseEnd; ++Base) {
8024    if (Base->isVirtual())
8025      continue;
8026
8027    if (!hasMoveOrIsTriviallyCopyable(S, Base->getType(), IsConstructor))
8028      return false;
8029  }
8030
8031  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
8032                                          BaseEnd = ClassDecl->vbases_end();
8033       Base != BaseEnd; ++Base) {
8034    if (!hasMoveOrIsTriviallyCopyable(S, Base->getType(), IsConstructor))
8035      return false;
8036  }
8037
8038  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
8039                                     FieldEnd = ClassDecl->field_end();
8040       Field != FieldEnd; ++Field) {
8041    if (!hasMoveOrIsTriviallyCopyable(S, Field->getType(), IsConstructor))
8042      return false;
8043  }
8044
8045  return true;
8046}
8047
8048CXXMethodDecl *Sema::DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl) {
8049  // C++11 [class.copy]p20:
8050  //   If the definition of a class X does not explicitly declare a move
8051  //   assignment operator, one will be implicitly declared as defaulted
8052  //   if and only if:
8053  //
8054  //   - [first 4 bullets]
8055  assert(ClassDecl->needsImplicitMoveAssignment());
8056
8057  // [Checked after we build the declaration]
8058  //   - the move assignment operator would not be implicitly defined as
8059  //     deleted,
8060
8061  // [DR1402]:
8062  //   - X has no direct or indirect virtual base class with a non-trivial
8063  //     move assignment operator, and
8064  //   - each of X's non-static data members and direct or virtual base classes
8065  //     has a type that either has a move assignment operator or is trivially
8066  //     copyable.
8067  if (hasVirtualBaseWithNonTrivialMoveAssignment(*this, ClassDecl) ||
8068      !subobjectsHaveMoveOrTrivialCopy(*this, ClassDecl,/*Constructor*/false)) {
8069    ClassDecl->setFailedImplicitMoveAssignment();
8070    return 0;
8071  }
8072
8073  // Note: The following rules are largely analoguous to the move
8074  // constructor rules.
8075
8076  ImplicitExceptionSpecification Spec(
8077      ComputeDefaultedMoveAssignmentExceptionSpec(ClassDecl));
8078
8079  QualType ArgType = Context.getTypeDeclType(ClassDecl);
8080  QualType RetType = Context.getLValueReferenceType(ArgType);
8081  ArgType = Context.getRValueReferenceType(ArgType);
8082
8083  //   An implicitly-declared move assignment operator is an inline public
8084  //   member of its class.
8085  FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
8086  DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
8087  SourceLocation ClassLoc = ClassDecl->getLocation();
8088  DeclarationNameInfo NameInfo(Name, ClassLoc);
8089  CXXMethodDecl *MoveAssignment
8090    = CXXMethodDecl::Create(Context, ClassDecl, ClassLoc, NameInfo,
8091                            Context.getFunctionType(RetType, &ArgType, 1, EPI),
8092                            /*TInfo=*/0, /*isStatic=*/false,
8093                            /*StorageClassAsWritten=*/SC_None,
8094                            /*isInline=*/true,
8095                            /*isConstexpr=*/false,
8096                            SourceLocation());
8097  MoveAssignment->setAccess(AS_public);
8098  MoveAssignment->setDefaulted();
8099  MoveAssignment->setImplicit();
8100  MoveAssignment->setTrivial(ClassDecl->hasTrivialMoveAssignment());
8101
8102  // Add the parameter to the operator.
8103  ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveAssignment,
8104                                               ClassLoc, ClassLoc, /*Id=*/0,
8105                                               ArgType, /*TInfo=*/0,
8106                                               SC_None,
8107                                               SC_None, 0);
8108  MoveAssignment->setParams(FromParam);
8109
8110  // Note that we have added this copy-assignment operator.
8111  ++ASTContext::NumImplicitMoveAssignmentOperatorsDeclared;
8112
8113  // C++0x [class.copy]p9:
8114  //   If the definition of a class X does not explicitly declare a move
8115  //   assignment operator, one will be implicitly declared as defaulted if and
8116  //   only if:
8117  //   [...]
8118  //   - the move assignment operator would not be implicitly defined as
8119  //     deleted.
8120  if (ShouldDeleteSpecialMember(MoveAssignment, CXXMoveAssignment)) {
8121    // Cache this result so that we don't try to generate this over and over
8122    // on every lookup, leaking memory and wasting time.
8123    ClassDecl->setFailedImplicitMoveAssignment();
8124    return 0;
8125  }
8126
8127  if (Scope *S = getScopeForContext(ClassDecl))
8128    PushOnScopeChains(MoveAssignment, S, false);
8129  ClassDecl->addDecl(MoveAssignment);
8130
8131  AddOverriddenMethods(ClassDecl, MoveAssignment);
8132  return MoveAssignment;
8133}
8134
8135void Sema::DefineImplicitMoveAssignment(SourceLocation CurrentLocation,
8136                                        CXXMethodDecl *MoveAssignOperator) {
8137  assert((MoveAssignOperator->isDefaulted() &&
8138          MoveAssignOperator->isOverloadedOperator() &&
8139          MoveAssignOperator->getOverloadedOperator() == OO_Equal &&
8140          !MoveAssignOperator->doesThisDeclarationHaveABody() &&
8141          !MoveAssignOperator->isDeleted()) &&
8142         "DefineImplicitMoveAssignment called for wrong function");
8143
8144  CXXRecordDecl *ClassDecl = MoveAssignOperator->getParent();
8145
8146  if (ClassDecl->isInvalidDecl() || MoveAssignOperator->isInvalidDecl()) {
8147    MoveAssignOperator->setInvalidDecl();
8148    return;
8149  }
8150
8151  MoveAssignOperator->setUsed();
8152
8153  ImplicitlyDefinedFunctionScope Scope(*this, MoveAssignOperator);
8154  DiagnosticErrorTrap Trap(Diags);
8155
8156  // C++0x [class.copy]p28:
8157  //   The implicitly-defined or move assignment operator for a non-union class
8158  //   X performs memberwise move assignment of its subobjects. The direct base
8159  //   classes of X are assigned first, in the order of their declaration in the
8160  //   base-specifier-list, and then the immediate non-static data members of X
8161  //   are assigned, in the order in which they were declared in the class
8162  //   definition.
8163
8164  // The statements that form the synthesized function body.
8165  ASTOwningVector<Stmt*> Statements(*this);
8166
8167  // The parameter for the "other" object, which we are move from.
8168  ParmVarDecl *Other = MoveAssignOperator->getParamDecl(0);
8169  QualType OtherRefType = Other->getType()->
8170      getAs<RValueReferenceType>()->getPointeeType();
8171  assert(OtherRefType.getQualifiers() == 0 &&
8172         "Bad argument type of defaulted move assignment");
8173
8174  // Our location for everything implicitly-generated.
8175  SourceLocation Loc = MoveAssignOperator->getLocation();
8176
8177  // Construct a reference to the "other" object. We'll be using this
8178  // throughout the generated ASTs.
8179  Expr *OtherRef = BuildDeclRefExpr(Other, OtherRefType, VK_LValue, Loc).take();
8180  assert(OtherRef && "Reference to parameter cannot fail!");
8181  // Cast to rvalue.
8182  OtherRef = CastForMoving(*this, OtherRef);
8183
8184  // Construct the "this" pointer. We'll be using this throughout the generated
8185  // ASTs.
8186  Expr *This = ActOnCXXThis(Loc).takeAs<Expr>();
8187  assert(This && "Reference to this cannot fail!");
8188
8189  // Assign base classes.
8190  bool Invalid = false;
8191  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
8192       E = ClassDecl->bases_end(); Base != E; ++Base) {
8193    // Form the assignment:
8194    //   static_cast<Base*>(this)->Base::operator=(static_cast<Base&&>(other));
8195    QualType BaseType = Base->getType().getUnqualifiedType();
8196    if (!BaseType->isRecordType()) {
8197      Invalid = true;
8198      continue;
8199    }
8200
8201    CXXCastPath BasePath;
8202    BasePath.push_back(Base);
8203
8204    // Construct the "from" expression, which is an implicit cast to the
8205    // appropriately-qualified base type.
8206    Expr *From = OtherRef;
8207    From = ImpCastExprToType(From, BaseType, CK_UncheckedDerivedToBase,
8208                             VK_XValue, &BasePath).take();
8209
8210    // Dereference "this".
8211    ExprResult To = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
8212
8213    // Implicitly cast "this" to the appropriately-qualified base type.
8214    To = ImpCastExprToType(To.take(),
8215                           Context.getCVRQualifiedType(BaseType,
8216                                     MoveAssignOperator->getTypeQualifiers()),
8217                           CK_UncheckedDerivedToBase,
8218                           VK_LValue, &BasePath);
8219
8220    // Build the move.
8221    StmtResult Move = BuildSingleCopyAssign(*this, Loc, BaseType,
8222                                            To.get(), From,
8223                                            /*CopyingBaseSubobject=*/true,
8224                                            /*Copying=*/false);
8225    if (Move.isInvalid()) {
8226      Diag(CurrentLocation, diag::note_member_synthesized_at)
8227        << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8228      MoveAssignOperator->setInvalidDecl();
8229      return;
8230    }
8231
8232    // Success! Record the move.
8233    Statements.push_back(Move.takeAs<Expr>());
8234  }
8235
8236  // \brief Reference to the __builtin_memcpy function.
8237  Expr *BuiltinMemCpyRef = 0;
8238  // \brief Reference to the __builtin_objc_memmove_collectable function.
8239  Expr *CollectableMemCpyRef = 0;
8240
8241  // Assign non-static members.
8242  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
8243                                  FieldEnd = ClassDecl->field_end();
8244       Field != FieldEnd; ++Field) {
8245    if (Field->isUnnamedBitfield())
8246      continue;
8247
8248    // Check for members of reference type; we can't move those.
8249    if (Field->getType()->isReferenceType()) {
8250      Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
8251        << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
8252      Diag(Field->getLocation(), diag::note_declared_at);
8253      Diag(CurrentLocation, diag::note_member_synthesized_at)
8254        << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8255      Invalid = true;
8256      continue;
8257    }
8258
8259    // Check for members of const-qualified, non-class type.
8260    QualType BaseType = Context.getBaseElementType(Field->getType());
8261    if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
8262      Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
8263        << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
8264      Diag(Field->getLocation(), diag::note_declared_at);
8265      Diag(CurrentLocation, diag::note_member_synthesized_at)
8266        << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8267      Invalid = true;
8268      continue;
8269    }
8270
8271    // Suppress assigning zero-width bitfields.
8272    if (Field->isBitField() && Field->getBitWidthValue(Context) == 0)
8273      continue;
8274
8275    QualType FieldType = Field->getType().getNonReferenceType();
8276    if (FieldType->isIncompleteArrayType()) {
8277      assert(ClassDecl->hasFlexibleArrayMember() &&
8278             "Incomplete array type is not valid");
8279      continue;
8280    }
8281
8282    // Build references to the field in the object we're copying from and to.
8283    CXXScopeSpec SS; // Intentionally empty
8284    LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
8285                              LookupMemberName);
8286    MemberLookup.addDecl(*Field);
8287    MemberLookup.resolveKind();
8288    ExprResult From = BuildMemberReferenceExpr(OtherRef, OtherRefType,
8289                                               Loc, /*IsArrow=*/false,
8290                                               SS, SourceLocation(), 0,
8291                                               MemberLookup, 0);
8292    ExprResult To = BuildMemberReferenceExpr(This, This->getType(),
8293                                             Loc, /*IsArrow=*/true,
8294                                             SS, SourceLocation(), 0,
8295                                             MemberLookup, 0);
8296    assert(!From.isInvalid() && "Implicit field reference cannot fail");
8297    assert(!To.isInvalid() && "Implicit field reference cannot fail");
8298
8299    assert(!From.get()->isLValue() && // could be xvalue or prvalue
8300        "Member reference with rvalue base must be rvalue except for reference "
8301        "members, which aren't allowed for move assignment.");
8302
8303    // If the field should be copied with __builtin_memcpy rather than via
8304    // explicit assignments, do so. This optimization only applies for arrays
8305    // of scalars and arrays of class type with trivial move-assignment
8306    // operators.
8307    if (FieldType->isArrayType() && !FieldType.isVolatileQualified()
8308        && BaseType.hasTrivialAssignment(Context, /*Copying=*/false)) {
8309      // Compute the size of the memory buffer to be copied.
8310      QualType SizeType = Context.getSizeType();
8311      llvm::APInt Size(Context.getTypeSize(SizeType),
8312                       Context.getTypeSizeInChars(BaseType).getQuantity());
8313      for (const ConstantArrayType *Array
8314              = Context.getAsConstantArrayType(FieldType);
8315           Array;
8316           Array = Context.getAsConstantArrayType(Array->getElementType())) {
8317        llvm::APInt ArraySize
8318          = Array->getSize().zextOrTrunc(Size.getBitWidth());
8319        Size *= ArraySize;
8320      }
8321
8322      // Take the address of the field references for "from" and "to". We
8323      // directly construct UnaryOperators here because semantic analysis
8324      // does not permit us to take the address of an xvalue.
8325      From = new (Context) UnaryOperator(From.get(), UO_AddrOf,
8326                             Context.getPointerType(From.get()->getType()),
8327                             VK_RValue, OK_Ordinary, Loc);
8328      To = new (Context) UnaryOperator(To.get(), UO_AddrOf,
8329                           Context.getPointerType(To.get()->getType()),
8330                           VK_RValue, OK_Ordinary, Loc);
8331
8332      bool NeedsCollectableMemCpy =
8333          (BaseType->isRecordType() &&
8334           BaseType->getAs<RecordType>()->getDecl()->hasObjectMember());
8335
8336      if (NeedsCollectableMemCpy) {
8337        if (!CollectableMemCpyRef) {
8338          // Create a reference to the __builtin_objc_memmove_collectable function.
8339          LookupResult R(*this,
8340                         &Context.Idents.get("__builtin_objc_memmove_collectable"),
8341                         Loc, LookupOrdinaryName);
8342          LookupName(R, TUScope, true);
8343
8344          FunctionDecl *CollectableMemCpy = R.getAsSingle<FunctionDecl>();
8345          if (!CollectableMemCpy) {
8346            // Something went horribly wrong earlier, and we will have
8347            // complained about it.
8348            Invalid = true;
8349            continue;
8350          }
8351
8352          CollectableMemCpyRef = BuildDeclRefExpr(CollectableMemCpy,
8353                                                  CollectableMemCpy->getType(),
8354                                                  VK_LValue, Loc, 0).take();
8355          assert(CollectableMemCpyRef && "Builtin reference cannot fail");
8356        }
8357      }
8358      // Create a reference to the __builtin_memcpy builtin function.
8359      else if (!BuiltinMemCpyRef) {
8360        LookupResult R(*this, &Context.Idents.get("__builtin_memcpy"), Loc,
8361                       LookupOrdinaryName);
8362        LookupName(R, TUScope, true);
8363
8364        FunctionDecl *BuiltinMemCpy = R.getAsSingle<FunctionDecl>();
8365        if (!BuiltinMemCpy) {
8366          // Something went horribly wrong earlier, and we will have complained
8367          // about it.
8368          Invalid = true;
8369          continue;
8370        }
8371
8372        BuiltinMemCpyRef = BuildDeclRefExpr(BuiltinMemCpy,
8373                                            BuiltinMemCpy->getType(),
8374                                            VK_LValue, Loc, 0).take();
8375        assert(BuiltinMemCpyRef && "Builtin reference cannot fail");
8376      }
8377
8378      ASTOwningVector<Expr*> CallArgs(*this);
8379      CallArgs.push_back(To.takeAs<Expr>());
8380      CallArgs.push_back(From.takeAs<Expr>());
8381      CallArgs.push_back(IntegerLiteral::Create(Context, Size, SizeType, Loc));
8382      ExprResult Call = ExprError();
8383      if (NeedsCollectableMemCpy)
8384        Call = ActOnCallExpr(/*Scope=*/0,
8385                             CollectableMemCpyRef,
8386                             Loc, move_arg(CallArgs),
8387                             Loc);
8388      else
8389        Call = ActOnCallExpr(/*Scope=*/0,
8390                             BuiltinMemCpyRef,
8391                             Loc, move_arg(CallArgs),
8392                             Loc);
8393
8394      assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!");
8395      Statements.push_back(Call.takeAs<Expr>());
8396      continue;
8397    }
8398
8399    // Build the move of this field.
8400    StmtResult Move = BuildSingleCopyAssign(*this, Loc, FieldType,
8401                                            To.get(), From.get(),
8402                                            /*CopyingBaseSubobject=*/false,
8403                                            /*Copying=*/false);
8404    if (Move.isInvalid()) {
8405      Diag(CurrentLocation, diag::note_member_synthesized_at)
8406        << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8407      MoveAssignOperator->setInvalidDecl();
8408      return;
8409    }
8410
8411    // Success! Record the copy.
8412    Statements.push_back(Move.takeAs<Stmt>());
8413  }
8414
8415  if (!Invalid) {
8416    // Add a "return *this;"
8417    ExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
8418
8419    StmtResult Return = ActOnReturnStmt(Loc, ThisObj.get());
8420    if (Return.isInvalid())
8421      Invalid = true;
8422    else {
8423      Statements.push_back(Return.takeAs<Stmt>());
8424
8425      if (Trap.hasErrorOccurred()) {
8426        Diag(CurrentLocation, diag::note_member_synthesized_at)
8427          << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8428        Invalid = true;
8429      }
8430    }
8431  }
8432
8433  if (Invalid) {
8434    MoveAssignOperator->setInvalidDecl();
8435    return;
8436  }
8437
8438  StmtResult Body;
8439  {
8440    CompoundScopeRAII CompoundScope(*this);
8441    Body = ActOnCompoundStmt(Loc, Loc, move_arg(Statements),
8442                             /*isStmtExpr=*/false);
8443    assert(!Body.isInvalid() && "Compound statement creation cannot fail");
8444  }
8445  MoveAssignOperator->setBody(Body.takeAs<Stmt>());
8446
8447  if (ASTMutationListener *L = getASTMutationListener()) {
8448    L->CompletedImplicitDefinition(MoveAssignOperator);
8449  }
8450}
8451
8452std::pair<Sema::ImplicitExceptionSpecification, bool>
8453Sema::ComputeDefaultedCopyCtorExceptionSpecAndConst(CXXRecordDecl *ClassDecl) {
8454  if (ClassDecl->isInvalidDecl())
8455    return std::make_pair(ImplicitExceptionSpecification(*this), true);
8456
8457  // C++ [class.copy]p5:
8458  //   The implicitly-declared copy constructor for a class X will
8459  //   have the form
8460  //
8461  //       X::X(const X&)
8462  //
8463  //   if
8464  // FIXME: It ought to be possible to store this on the record.
8465  bool HasConstCopyConstructor = true;
8466
8467  //     -- each direct or virtual base class B of X has a copy
8468  //        constructor whose first parameter is of type const B& or
8469  //        const volatile B&, and
8470  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
8471                                       BaseEnd = ClassDecl->bases_end();
8472       HasConstCopyConstructor && Base != BaseEnd;
8473       ++Base) {
8474    // Virtual bases are handled below.
8475    if (Base->isVirtual())
8476      continue;
8477
8478    CXXRecordDecl *BaseClassDecl
8479      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8480    HasConstCopyConstructor &=
8481      (bool)LookupCopyingConstructor(BaseClassDecl, Qualifiers::Const);
8482  }
8483
8484  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
8485                                       BaseEnd = ClassDecl->vbases_end();
8486       HasConstCopyConstructor && Base != BaseEnd;
8487       ++Base) {
8488    CXXRecordDecl *BaseClassDecl
8489      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8490    HasConstCopyConstructor &=
8491      (bool)LookupCopyingConstructor(BaseClassDecl, Qualifiers::Const);
8492  }
8493
8494  //     -- for all the nonstatic data members of X that are of a
8495  //        class type M (or array thereof), each such class type
8496  //        has a copy constructor whose first parameter is of type
8497  //        const M& or const volatile M&.
8498  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
8499                                  FieldEnd = ClassDecl->field_end();
8500       HasConstCopyConstructor && Field != FieldEnd;
8501       ++Field) {
8502    QualType FieldType = Context.getBaseElementType(Field->getType());
8503    if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) {
8504      HasConstCopyConstructor &=
8505        (bool)LookupCopyingConstructor(FieldClassDecl, Qualifiers::Const);
8506    }
8507  }
8508  //   Otherwise, the implicitly declared copy constructor will have
8509  //   the form
8510  //
8511  //       X::X(X&)
8512
8513  // C++ [except.spec]p14:
8514  //   An implicitly declared special member function (Clause 12) shall have an
8515  //   exception-specification. [...]
8516  ImplicitExceptionSpecification ExceptSpec(*this);
8517  unsigned Quals = HasConstCopyConstructor? Qualifiers::Const : 0;
8518  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
8519                                       BaseEnd = ClassDecl->bases_end();
8520       Base != BaseEnd;
8521       ++Base) {
8522    // Virtual bases are handled below.
8523    if (Base->isVirtual())
8524      continue;
8525
8526    CXXRecordDecl *BaseClassDecl
8527      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8528    if (CXXConstructorDecl *CopyConstructor =
8529          LookupCopyingConstructor(BaseClassDecl, Quals))
8530      ExceptSpec.CalledDecl(Base->getLocStart(), CopyConstructor);
8531  }
8532  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
8533                                       BaseEnd = ClassDecl->vbases_end();
8534       Base != BaseEnd;
8535       ++Base) {
8536    CXXRecordDecl *BaseClassDecl
8537      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8538    if (CXXConstructorDecl *CopyConstructor =
8539          LookupCopyingConstructor(BaseClassDecl, Quals))
8540      ExceptSpec.CalledDecl(Base->getLocStart(), CopyConstructor);
8541  }
8542  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
8543                                  FieldEnd = ClassDecl->field_end();
8544       Field != FieldEnd;
8545       ++Field) {
8546    QualType FieldType = Context.getBaseElementType(Field->getType());
8547    if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) {
8548      if (CXXConstructorDecl *CopyConstructor =
8549        LookupCopyingConstructor(FieldClassDecl, Quals))
8550      ExceptSpec.CalledDecl(Field->getLocation(), CopyConstructor);
8551    }
8552  }
8553
8554  return std::make_pair(ExceptSpec, HasConstCopyConstructor);
8555}
8556
8557CXXConstructorDecl *Sema::DeclareImplicitCopyConstructor(
8558                                                    CXXRecordDecl *ClassDecl) {
8559  // C++ [class.copy]p4:
8560  //   If the class definition does not explicitly declare a copy
8561  //   constructor, one is declared implicitly.
8562
8563  ImplicitExceptionSpecification Spec(*this);
8564  bool Const;
8565  llvm::tie(Spec, Const) =
8566    ComputeDefaultedCopyCtorExceptionSpecAndConst(ClassDecl);
8567
8568  QualType ClassType = Context.getTypeDeclType(ClassDecl);
8569  QualType ArgType = ClassType;
8570  if (Const)
8571    ArgType = ArgType.withConst();
8572  ArgType = Context.getLValueReferenceType(ArgType);
8573
8574  FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
8575
8576  bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
8577                                                     CXXCopyConstructor,
8578                                                     Const);
8579
8580  DeclarationName Name
8581    = Context.DeclarationNames.getCXXConstructorName(
8582                                           Context.getCanonicalType(ClassType));
8583  SourceLocation ClassLoc = ClassDecl->getLocation();
8584  DeclarationNameInfo NameInfo(Name, ClassLoc);
8585
8586  //   An implicitly-declared copy constructor is an inline public
8587  //   member of its class.
8588  CXXConstructorDecl *CopyConstructor = CXXConstructorDecl::Create(
8589      Context, ClassDecl, ClassLoc, NameInfo,
8590      Context.getFunctionType(Context.VoidTy, &ArgType, 1, EPI), /*TInfo=*/0,
8591      /*isExplicit=*/false, /*isInline=*/true, /*isImplicitlyDeclared=*/true,
8592      Constexpr);
8593  CopyConstructor->setAccess(AS_public);
8594  CopyConstructor->setDefaulted();
8595  CopyConstructor->setTrivial(ClassDecl->hasTrivialCopyConstructor());
8596
8597  // Note that we have declared this constructor.
8598  ++ASTContext::NumImplicitCopyConstructorsDeclared;
8599
8600  // Add the parameter to the constructor.
8601  ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyConstructor,
8602                                               ClassLoc, ClassLoc,
8603                                               /*IdentifierInfo=*/0,
8604                                               ArgType, /*TInfo=*/0,
8605                                               SC_None,
8606                                               SC_None, 0);
8607  CopyConstructor->setParams(FromParam);
8608
8609  if (Scope *S = getScopeForContext(ClassDecl))
8610    PushOnScopeChains(CopyConstructor, S, false);
8611  ClassDecl->addDecl(CopyConstructor);
8612
8613  // C++11 [class.copy]p8:
8614  //   ... If the class definition does not explicitly declare a copy
8615  //   constructor, there is no user-declared move constructor, and there is no
8616  //   user-declared move assignment operator, a copy constructor is implicitly
8617  //   declared as defaulted.
8618  if (ShouldDeleteSpecialMember(CopyConstructor, CXXCopyConstructor))
8619    CopyConstructor->setDeletedAsWritten();
8620
8621  return CopyConstructor;
8622}
8623
8624void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
8625                                   CXXConstructorDecl *CopyConstructor) {
8626  assert((CopyConstructor->isDefaulted() &&
8627          CopyConstructor->isCopyConstructor() &&
8628          !CopyConstructor->doesThisDeclarationHaveABody() &&
8629          !CopyConstructor->isDeleted()) &&
8630         "DefineImplicitCopyConstructor - call it for implicit copy ctor");
8631
8632  CXXRecordDecl *ClassDecl = CopyConstructor->getParent();
8633  assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor");
8634
8635  ImplicitlyDefinedFunctionScope Scope(*this, CopyConstructor);
8636  DiagnosticErrorTrap Trap(Diags);
8637
8638  if (SetCtorInitializers(CopyConstructor, 0, 0, /*AnyErrors=*/false) ||
8639      Trap.hasErrorOccurred()) {
8640    Diag(CurrentLocation, diag::note_member_synthesized_at)
8641      << CXXCopyConstructor << Context.getTagDeclType(ClassDecl);
8642    CopyConstructor->setInvalidDecl();
8643  }  else {
8644    Sema::CompoundScopeRAII CompoundScope(*this);
8645    CopyConstructor->setBody(ActOnCompoundStmt(CopyConstructor->getLocation(),
8646                                               CopyConstructor->getLocation(),
8647                                               MultiStmtArg(*this, 0, 0),
8648                                               /*isStmtExpr=*/false)
8649                                                              .takeAs<Stmt>());
8650    CopyConstructor->setImplicitlyDefined(true);
8651  }
8652
8653  CopyConstructor->setUsed();
8654  if (ASTMutationListener *L = getASTMutationListener()) {
8655    L->CompletedImplicitDefinition(CopyConstructor);
8656  }
8657}
8658
8659Sema::ImplicitExceptionSpecification
8660Sema::ComputeDefaultedMoveCtorExceptionSpec(CXXRecordDecl *ClassDecl) {
8661  // C++ [except.spec]p14:
8662  //   An implicitly declared special member function (Clause 12) shall have an
8663  //   exception-specification. [...]
8664  ImplicitExceptionSpecification ExceptSpec(*this);
8665  if (ClassDecl->isInvalidDecl())
8666    return ExceptSpec;
8667
8668  // Direct base-class constructors.
8669  for (CXXRecordDecl::base_class_iterator B = ClassDecl->bases_begin(),
8670                                       BEnd = ClassDecl->bases_end();
8671       B != BEnd; ++B) {
8672    if (B->isVirtual()) // Handled below.
8673      continue;
8674
8675    if (const RecordType *BaseType = B->getType()->getAs<RecordType>()) {
8676      CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
8677      CXXConstructorDecl *Constructor = LookupMovingConstructor(BaseClassDecl);
8678      // If this is a deleted function, add it anyway. This might be conformant
8679      // with the standard. This might not. I'm not sure. It might not matter.
8680      if (Constructor)
8681        ExceptSpec.CalledDecl(B->getLocStart(), Constructor);
8682    }
8683  }
8684
8685  // Virtual base-class constructors.
8686  for (CXXRecordDecl::base_class_iterator B = ClassDecl->vbases_begin(),
8687                                       BEnd = ClassDecl->vbases_end();
8688       B != BEnd; ++B) {
8689    if (const RecordType *BaseType = B->getType()->getAs<RecordType>()) {
8690      CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
8691      CXXConstructorDecl *Constructor = LookupMovingConstructor(BaseClassDecl);
8692      // If this is a deleted function, add it anyway. This might be conformant
8693      // with the standard. This might not. I'm not sure. It might not matter.
8694      if (Constructor)
8695        ExceptSpec.CalledDecl(B->getLocStart(), Constructor);
8696    }
8697  }
8698
8699  // Field constructors.
8700  for (RecordDecl::field_iterator F = ClassDecl->field_begin(),
8701                               FEnd = ClassDecl->field_end();
8702       F != FEnd; ++F) {
8703    if (const RecordType *RecordTy
8704              = Context.getBaseElementType(F->getType())->getAs<RecordType>()) {
8705      CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
8706      CXXConstructorDecl *Constructor = LookupMovingConstructor(FieldRecDecl);
8707      // If this is a deleted function, add it anyway. This might be conformant
8708      // with the standard. This might not. I'm not sure. It might not matter.
8709      // In particular, the problem is that this function never gets called. It
8710      // might just be ill-formed because this function attempts to refer to
8711      // a deleted function here.
8712      if (Constructor)
8713        ExceptSpec.CalledDecl(F->getLocation(), Constructor);
8714    }
8715  }
8716
8717  return ExceptSpec;
8718}
8719
8720CXXConstructorDecl *Sema::DeclareImplicitMoveConstructor(
8721                                                    CXXRecordDecl *ClassDecl) {
8722  // C++11 [class.copy]p9:
8723  //   If the definition of a class X does not explicitly declare a move
8724  //   constructor, one will be implicitly declared as defaulted if and only if:
8725  //
8726  //   - [first 4 bullets]
8727  assert(ClassDecl->needsImplicitMoveConstructor());
8728
8729  // [Checked after we build the declaration]
8730  //   - the move assignment operator would not be implicitly defined as
8731  //     deleted,
8732
8733  // [DR1402]:
8734  //   - each of X's non-static data members and direct or virtual base classes
8735  //     has a type that either has a move constructor or is trivially copyable.
8736  if (!subobjectsHaveMoveOrTrivialCopy(*this, ClassDecl, /*Constructor*/true)) {
8737    ClassDecl->setFailedImplicitMoveConstructor();
8738    return 0;
8739  }
8740
8741  ImplicitExceptionSpecification Spec(
8742      ComputeDefaultedMoveCtorExceptionSpec(ClassDecl));
8743
8744  QualType ClassType = Context.getTypeDeclType(ClassDecl);
8745  QualType ArgType = Context.getRValueReferenceType(ClassType);
8746
8747  FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
8748
8749  bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
8750                                                     CXXMoveConstructor,
8751                                                     false);
8752
8753  DeclarationName Name
8754    = Context.DeclarationNames.getCXXConstructorName(
8755                                           Context.getCanonicalType(ClassType));
8756  SourceLocation ClassLoc = ClassDecl->getLocation();
8757  DeclarationNameInfo NameInfo(Name, ClassLoc);
8758
8759  // C++0x [class.copy]p11:
8760  //   An implicitly-declared copy/move constructor is an inline public
8761  //   member of its class.
8762  CXXConstructorDecl *MoveConstructor = CXXConstructorDecl::Create(
8763      Context, ClassDecl, ClassLoc, NameInfo,
8764      Context.getFunctionType(Context.VoidTy, &ArgType, 1, EPI), /*TInfo=*/0,
8765      /*isExplicit=*/false, /*isInline=*/true, /*isImplicitlyDeclared=*/true,
8766      Constexpr);
8767  MoveConstructor->setAccess(AS_public);
8768  MoveConstructor->setDefaulted();
8769  MoveConstructor->setTrivial(ClassDecl->hasTrivialMoveConstructor());
8770
8771  // Add the parameter to the constructor.
8772  ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveConstructor,
8773                                               ClassLoc, ClassLoc,
8774                                               /*IdentifierInfo=*/0,
8775                                               ArgType, /*TInfo=*/0,
8776                                               SC_None,
8777                                               SC_None, 0);
8778  MoveConstructor->setParams(FromParam);
8779
8780  // C++0x [class.copy]p9:
8781  //   If the definition of a class X does not explicitly declare a move
8782  //   constructor, one will be implicitly declared as defaulted if and only if:
8783  //   [...]
8784  //   - the move constructor would not be implicitly defined as deleted.
8785  if (ShouldDeleteSpecialMember(MoveConstructor, CXXMoveConstructor)) {
8786    // Cache this result so that we don't try to generate this over and over
8787    // on every lookup, leaking memory and wasting time.
8788    ClassDecl->setFailedImplicitMoveConstructor();
8789    return 0;
8790  }
8791
8792  // Note that we have declared this constructor.
8793  ++ASTContext::NumImplicitMoveConstructorsDeclared;
8794
8795  if (Scope *S = getScopeForContext(ClassDecl))
8796    PushOnScopeChains(MoveConstructor, S, false);
8797  ClassDecl->addDecl(MoveConstructor);
8798
8799  return MoveConstructor;
8800}
8801
8802void Sema::DefineImplicitMoveConstructor(SourceLocation CurrentLocation,
8803                                   CXXConstructorDecl *MoveConstructor) {
8804  assert((MoveConstructor->isDefaulted() &&
8805          MoveConstructor->isMoveConstructor() &&
8806          !MoveConstructor->doesThisDeclarationHaveABody() &&
8807          !MoveConstructor->isDeleted()) &&
8808         "DefineImplicitMoveConstructor - call it for implicit move ctor");
8809
8810  CXXRecordDecl *ClassDecl = MoveConstructor->getParent();
8811  assert(ClassDecl && "DefineImplicitMoveConstructor - invalid constructor");
8812
8813  ImplicitlyDefinedFunctionScope Scope(*this, MoveConstructor);
8814  DiagnosticErrorTrap Trap(Diags);
8815
8816  if (SetCtorInitializers(MoveConstructor, 0, 0, /*AnyErrors=*/false) ||
8817      Trap.hasErrorOccurred()) {
8818    Diag(CurrentLocation, diag::note_member_synthesized_at)
8819      << CXXMoveConstructor << Context.getTagDeclType(ClassDecl);
8820    MoveConstructor->setInvalidDecl();
8821  }  else {
8822    Sema::CompoundScopeRAII CompoundScope(*this);
8823    MoveConstructor->setBody(ActOnCompoundStmt(MoveConstructor->getLocation(),
8824                                               MoveConstructor->getLocation(),
8825                                               MultiStmtArg(*this, 0, 0),
8826                                               /*isStmtExpr=*/false)
8827                                                              .takeAs<Stmt>());
8828    MoveConstructor->setImplicitlyDefined(true);
8829  }
8830
8831  MoveConstructor->setUsed();
8832
8833  if (ASTMutationListener *L = getASTMutationListener()) {
8834    L->CompletedImplicitDefinition(MoveConstructor);
8835  }
8836}
8837
8838bool Sema::isImplicitlyDeleted(FunctionDecl *FD) {
8839  return FD->isDeleted() &&
8840         (FD->isDefaulted() || FD->isImplicit()) &&
8841         isa<CXXMethodDecl>(FD);
8842}
8843
8844/// \brief Mark the call operator of the given lambda closure type as "used".
8845static void markLambdaCallOperatorUsed(Sema &S, CXXRecordDecl *Lambda) {
8846  CXXMethodDecl *CallOperator
8847    = cast<CXXMethodDecl>(
8848        *Lambda->lookup(
8849          S.Context.DeclarationNames.getCXXOperatorName(OO_Call)).first);
8850  CallOperator->setReferenced();
8851  CallOperator->setUsed();
8852}
8853
8854void Sema::DefineImplicitLambdaToFunctionPointerConversion(
8855       SourceLocation CurrentLocation,
8856       CXXConversionDecl *Conv)
8857{
8858  CXXRecordDecl *Lambda = Conv->getParent();
8859
8860  // Make sure that the lambda call operator is marked used.
8861  markLambdaCallOperatorUsed(*this, Lambda);
8862
8863  Conv->setUsed();
8864
8865  ImplicitlyDefinedFunctionScope Scope(*this, Conv);
8866  DiagnosticErrorTrap Trap(Diags);
8867
8868  // Return the address of the __invoke function.
8869  DeclarationName InvokeName = &Context.Idents.get("__invoke");
8870  CXXMethodDecl *Invoke
8871    = cast<CXXMethodDecl>(*Lambda->lookup(InvokeName).first);
8872  Expr *FunctionRef = BuildDeclRefExpr(Invoke, Invoke->getType(),
8873                                       VK_LValue, Conv->getLocation()).take();
8874  assert(FunctionRef && "Can't refer to __invoke function?");
8875  Stmt *Return = ActOnReturnStmt(Conv->getLocation(), FunctionRef).take();
8876  Conv->setBody(new (Context) CompoundStmt(Context, &Return, 1,
8877                                           Conv->getLocation(),
8878                                           Conv->getLocation()));
8879
8880  // Fill in the __invoke function with a dummy implementation. IR generation
8881  // will fill in the actual details.
8882  Invoke->setUsed();
8883  Invoke->setReferenced();
8884  Invoke->setBody(new (Context) CompoundStmt(Context, 0, 0, Conv->getLocation(),
8885                                             Conv->getLocation()));
8886
8887  if (ASTMutationListener *L = getASTMutationListener()) {
8888    L->CompletedImplicitDefinition(Conv);
8889    L->CompletedImplicitDefinition(Invoke);
8890  }
8891}
8892
8893void Sema::DefineImplicitLambdaToBlockPointerConversion(
8894       SourceLocation CurrentLocation,
8895       CXXConversionDecl *Conv)
8896{
8897  Conv->setUsed();
8898
8899  ImplicitlyDefinedFunctionScope Scope(*this, Conv);
8900  DiagnosticErrorTrap Trap(Diags);
8901
8902  // Copy-initialize the lambda object as needed to capture it.
8903  Expr *This = ActOnCXXThis(CurrentLocation).take();
8904  Expr *DerefThis =CreateBuiltinUnaryOp(CurrentLocation, UO_Deref, This).take();
8905
8906  ExprResult BuildBlock = BuildBlockForLambdaConversion(CurrentLocation,
8907                                                        Conv->getLocation(),
8908                                                        Conv, DerefThis);
8909
8910  // If we're not under ARC, make sure we still get the _Block_copy/autorelease
8911  // behavior.  Note that only the general conversion function does this
8912  // (since it's unusable otherwise); in the case where we inline the
8913  // block literal, it has block literal lifetime semantics.
8914  if (!BuildBlock.isInvalid() && !getLangOpts().ObjCAutoRefCount)
8915    BuildBlock = ImplicitCastExpr::Create(Context, BuildBlock.get()->getType(),
8916                                          CK_CopyAndAutoreleaseBlockObject,
8917                                          BuildBlock.get(), 0, VK_RValue);
8918
8919  if (BuildBlock.isInvalid()) {
8920    Diag(CurrentLocation, diag::note_lambda_to_block_conv);
8921    Conv->setInvalidDecl();
8922    return;
8923  }
8924
8925  // Create the return statement that returns the block from the conversion
8926  // function.
8927  StmtResult Return = ActOnReturnStmt(Conv->getLocation(), BuildBlock.get());
8928  if (Return.isInvalid()) {
8929    Diag(CurrentLocation, diag::note_lambda_to_block_conv);
8930    Conv->setInvalidDecl();
8931    return;
8932  }
8933
8934  // Set the body of the conversion function.
8935  Stmt *ReturnS = Return.take();
8936  Conv->setBody(new (Context) CompoundStmt(Context, &ReturnS, 1,
8937                                           Conv->getLocation(),
8938                                           Conv->getLocation()));
8939
8940  // We're done; notify the mutation listener, if any.
8941  if (ASTMutationListener *L = getASTMutationListener()) {
8942    L->CompletedImplicitDefinition(Conv);
8943  }
8944}
8945
8946/// \brief Determine whether the given list arguments contains exactly one
8947/// "real" (non-default) argument.
8948static bool hasOneRealArgument(MultiExprArg Args) {
8949  switch (Args.size()) {
8950  case 0:
8951    return false;
8952
8953  default:
8954    if (!Args.get()[1]->isDefaultArgument())
8955      return false;
8956
8957    // fall through
8958  case 1:
8959    return !Args.get()[0]->isDefaultArgument();
8960  }
8961
8962  return false;
8963}
8964
8965ExprResult
8966Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
8967                            CXXConstructorDecl *Constructor,
8968                            MultiExprArg ExprArgs,
8969                            bool HadMultipleCandidates,
8970                            bool RequiresZeroInit,
8971                            unsigned ConstructKind,
8972                            SourceRange ParenRange) {
8973  bool Elidable = false;
8974
8975  // C++0x [class.copy]p34:
8976  //   When certain criteria are met, an implementation is allowed to
8977  //   omit the copy/move construction of a class object, even if the
8978  //   copy/move constructor and/or destructor for the object have
8979  //   side effects. [...]
8980  //     - when a temporary class object that has not been bound to a
8981  //       reference (12.2) would be copied/moved to a class object
8982  //       with the same cv-unqualified type, the copy/move operation
8983  //       can be omitted by constructing the temporary object
8984  //       directly into the target of the omitted copy/move
8985  if (ConstructKind == CXXConstructExpr::CK_Complete &&
8986      Constructor->isCopyOrMoveConstructor() && hasOneRealArgument(ExprArgs)) {
8987    Expr *SubExpr = ((Expr **)ExprArgs.get())[0];
8988    Elidable = SubExpr->isTemporaryObject(Context, Constructor->getParent());
8989  }
8990
8991  return BuildCXXConstructExpr(ConstructLoc, DeclInitType, Constructor,
8992                               Elidable, move(ExprArgs), HadMultipleCandidates,
8993                               RequiresZeroInit, ConstructKind, ParenRange);
8994}
8995
8996/// BuildCXXConstructExpr - Creates a complete call to a constructor,
8997/// including handling of its default argument expressions.
8998ExprResult
8999Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
9000                            CXXConstructorDecl *Constructor, bool Elidable,
9001                            MultiExprArg ExprArgs,
9002                            bool HadMultipleCandidates,
9003                            bool RequiresZeroInit,
9004                            unsigned ConstructKind,
9005                            SourceRange ParenRange) {
9006  unsigned NumExprs = ExprArgs.size();
9007  Expr **Exprs = (Expr **)ExprArgs.release();
9008
9009  for (specific_attr_iterator<NonNullAttr>
9010           i = Constructor->specific_attr_begin<NonNullAttr>(),
9011           e = Constructor->specific_attr_end<NonNullAttr>(); i != e; ++i) {
9012    const NonNullAttr *NonNull = *i;
9013    CheckNonNullArguments(NonNull, ExprArgs.get(), ConstructLoc);
9014  }
9015
9016  MarkFunctionReferenced(ConstructLoc, Constructor);
9017  return Owned(CXXConstructExpr::Create(Context, DeclInitType, ConstructLoc,
9018                                        Constructor, Elidable, Exprs, NumExprs,
9019                                        HadMultipleCandidates, /*FIXME*/false,
9020                                        RequiresZeroInit,
9021              static_cast<CXXConstructExpr::ConstructionKind>(ConstructKind),
9022                                        ParenRange));
9023}
9024
9025bool Sema::InitializeVarWithConstructor(VarDecl *VD,
9026                                        CXXConstructorDecl *Constructor,
9027                                        MultiExprArg Exprs,
9028                                        bool HadMultipleCandidates) {
9029  // FIXME: Provide the correct paren SourceRange when available.
9030  ExprResult TempResult =
9031    BuildCXXConstructExpr(VD->getLocation(), VD->getType(), Constructor,
9032                          move(Exprs), HadMultipleCandidates, false,
9033                          CXXConstructExpr::CK_Complete, SourceRange());
9034  if (TempResult.isInvalid())
9035    return true;
9036
9037  Expr *Temp = TempResult.takeAs<Expr>();
9038  CheckImplicitConversions(Temp, VD->getLocation());
9039  MarkFunctionReferenced(VD->getLocation(), Constructor);
9040  Temp = MaybeCreateExprWithCleanups(Temp);
9041  VD->setInit(Temp);
9042
9043  return false;
9044}
9045
9046void Sema::FinalizeVarWithDestructor(VarDecl *VD, const RecordType *Record) {
9047  if (VD->isInvalidDecl()) return;
9048
9049  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Record->getDecl());
9050  if (ClassDecl->isInvalidDecl()) return;
9051  if (ClassDecl->hasIrrelevantDestructor()) return;
9052  if (ClassDecl->isDependentContext()) return;
9053
9054  CXXDestructorDecl *Destructor = LookupDestructor(ClassDecl);
9055  MarkFunctionReferenced(VD->getLocation(), Destructor);
9056  CheckDestructorAccess(VD->getLocation(), Destructor,
9057                        PDiag(diag::err_access_dtor_var)
9058                        << VD->getDeclName()
9059                        << VD->getType());
9060  DiagnoseUseOfDecl(Destructor, VD->getLocation());
9061
9062  if (!VD->hasGlobalStorage()) return;
9063
9064  // Emit warning for non-trivial dtor in global scope (a real global,
9065  // class-static, function-static).
9066  Diag(VD->getLocation(), diag::warn_exit_time_destructor);
9067
9068  // TODO: this should be re-enabled for static locals by !CXAAtExit
9069  if (!VD->isStaticLocal())
9070    Diag(VD->getLocation(), diag::warn_global_destructor);
9071}
9072
9073/// \brief Given a constructor and the set of arguments provided for the
9074/// constructor, convert the arguments and add any required default arguments
9075/// to form a proper call to this constructor.
9076///
9077/// \returns true if an error occurred, false otherwise.
9078bool
9079Sema::CompleteConstructorCall(CXXConstructorDecl *Constructor,
9080                              MultiExprArg ArgsPtr,
9081                              SourceLocation Loc,
9082                              ASTOwningVector<Expr*> &ConvertedArgs,
9083                              bool AllowExplicit) {
9084  // FIXME: This duplicates a lot of code from Sema::ConvertArgumentsForCall.
9085  unsigned NumArgs = ArgsPtr.size();
9086  Expr **Args = (Expr **)ArgsPtr.get();
9087
9088  const FunctionProtoType *Proto
9089    = Constructor->getType()->getAs<FunctionProtoType>();
9090  assert(Proto && "Constructor without a prototype?");
9091  unsigned NumArgsInProto = Proto->getNumArgs();
9092
9093  // If too few arguments are available, we'll fill in the rest with defaults.
9094  if (NumArgs < NumArgsInProto)
9095    ConvertedArgs.reserve(NumArgsInProto);
9096  else
9097    ConvertedArgs.reserve(NumArgs);
9098
9099  VariadicCallType CallType =
9100    Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
9101  SmallVector<Expr *, 8> AllArgs;
9102  bool Invalid = GatherArgumentsForCall(Loc, Constructor,
9103                                        Proto, 0, Args, NumArgs, AllArgs,
9104                                        CallType, AllowExplicit);
9105  ConvertedArgs.append(AllArgs.begin(), AllArgs.end());
9106
9107  DiagnoseSentinelCalls(Constructor, Loc, AllArgs.data(), AllArgs.size());
9108
9109  // FIXME: Missing call to CheckFunctionCall or equivalent
9110
9111  return Invalid;
9112}
9113
9114static inline bool
9115CheckOperatorNewDeleteDeclarationScope(Sema &SemaRef,
9116                                       const FunctionDecl *FnDecl) {
9117  const DeclContext *DC = FnDecl->getDeclContext()->getRedeclContext();
9118  if (isa<NamespaceDecl>(DC)) {
9119    return SemaRef.Diag(FnDecl->getLocation(),
9120                        diag::err_operator_new_delete_declared_in_namespace)
9121      << FnDecl->getDeclName();
9122  }
9123
9124  if (isa<TranslationUnitDecl>(DC) &&
9125      FnDecl->getStorageClass() == SC_Static) {
9126    return SemaRef.Diag(FnDecl->getLocation(),
9127                        diag::err_operator_new_delete_declared_static)
9128      << FnDecl->getDeclName();
9129  }
9130
9131  return false;
9132}
9133
9134static inline bool
9135CheckOperatorNewDeleteTypes(Sema &SemaRef, const FunctionDecl *FnDecl,
9136                            CanQualType ExpectedResultType,
9137                            CanQualType ExpectedFirstParamType,
9138                            unsigned DependentParamTypeDiag,
9139                            unsigned InvalidParamTypeDiag) {
9140  QualType ResultType =
9141    FnDecl->getType()->getAs<FunctionType>()->getResultType();
9142
9143  // Check that the result type is not dependent.
9144  if (ResultType->isDependentType())
9145    return SemaRef.Diag(FnDecl->getLocation(),
9146                        diag::err_operator_new_delete_dependent_result_type)
9147    << FnDecl->getDeclName() << ExpectedResultType;
9148
9149  // Check that the result type is what we expect.
9150  if (SemaRef.Context.getCanonicalType(ResultType) != ExpectedResultType)
9151    return SemaRef.Diag(FnDecl->getLocation(),
9152                        diag::err_operator_new_delete_invalid_result_type)
9153    << FnDecl->getDeclName() << ExpectedResultType;
9154
9155  // A function template must have at least 2 parameters.
9156  if (FnDecl->getDescribedFunctionTemplate() && FnDecl->getNumParams() < 2)
9157    return SemaRef.Diag(FnDecl->getLocation(),
9158                      diag::err_operator_new_delete_template_too_few_parameters)
9159        << FnDecl->getDeclName();
9160
9161  // The function decl must have at least 1 parameter.
9162  if (FnDecl->getNumParams() == 0)
9163    return SemaRef.Diag(FnDecl->getLocation(),
9164                        diag::err_operator_new_delete_too_few_parameters)
9165      << FnDecl->getDeclName();
9166
9167  // Check the the first parameter type is not dependent.
9168  QualType FirstParamType = FnDecl->getParamDecl(0)->getType();
9169  if (FirstParamType->isDependentType())
9170    return SemaRef.Diag(FnDecl->getLocation(), DependentParamTypeDiag)
9171      << FnDecl->getDeclName() << ExpectedFirstParamType;
9172
9173  // Check that the first parameter type is what we expect.
9174  if (SemaRef.Context.getCanonicalType(FirstParamType).getUnqualifiedType() !=
9175      ExpectedFirstParamType)
9176    return SemaRef.Diag(FnDecl->getLocation(), InvalidParamTypeDiag)
9177    << FnDecl->getDeclName() << ExpectedFirstParamType;
9178
9179  return false;
9180}
9181
9182static bool
9183CheckOperatorNewDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
9184  // C++ [basic.stc.dynamic.allocation]p1:
9185  //   A program is ill-formed if an allocation function is declared in a
9186  //   namespace scope other than global scope or declared static in global
9187  //   scope.
9188  if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
9189    return true;
9190
9191  CanQualType SizeTy =
9192    SemaRef.Context.getCanonicalType(SemaRef.Context.getSizeType());
9193
9194  // C++ [basic.stc.dynamic.allocation]p1:
9195  //  The return type shall be void*. The first parameter shall have type
9196  //  std::size_t.
9197  if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidPtrTy,
9198                                  SizeTy,
9199                                  diag::err_operator_new_dependent_param_type,
9200                                  diag::err_operator_new_param_type))
9201    return true;
9202
9203  // C++ [basic.stc.dynamic.allocation]p1:
9204  //  The first parameter shall not have an associated default argument.
9205  if (FnDecl->getParamDecl(0)->hasDefaultArg())
9206    return SemaRef.Diag(FnDecl->getLocation(),
9207                        diag::err_operator_new_default_arg)
9208      << FnDecl->getDeclName() << FnDecl->getParamDecl(0)->getDefaultArgRange();
9209
9210  return false;
9211}
9212
9213static bool
9214CheckOperatorDeleteDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
9215  // C++ [basic.stc.dynamic.deallocation]p1:
9216  //   A program is ill-formed if deallocation functions are declared in a
9217  //   namespace scope other than global scope or declared static in global
9218  //   scope.
9219  if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
9220    return true;
9221
9222  // C++ [basic.stc.dynamic.deallocation]p2:
9223  //   Each deallocation function shall return void and its first parameter
9224  //   shall be void*.
9225  if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidTy,
9226                                  SemaRef.Context.VoidPtrTy,
9227                                 diag::err_operator_delete_dependent_param_type,
9228                                 diag::err_operator_delete_param_type))
9229    return true;
9230
9231  return false;
9232}
9233
9234/// CheckOverloadedOperatorDeclaration - Check whether the declaration
9235/// of this overloaded operator is well-formed. If so, returns false;
9236/// otherwise, emits appropriate diagnostics and returns true.
9237bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) {
9238  assert(FnDecl && FnDecl->isOverloadedOperator() &&
9239         "Expected an overloaded operator declaration");
9240
9241  OverloadedOperatorKind Op = FnDecl->getOverloadedOperator();
9242
9243  // C++ [over.oper]p5:
9244  //   The allocation and deallocation functions, operator new,
9245  //   operator new[], operator delete and operator delete[], are
9246  //   described completely in 3.7.3. The attributes and restrictions
9247  //   found in the rest of this subclause do not apply to them unless
9248  //   explicitly stated in 3.7.3.
9249  if (Op == OO_Delete || Op == OO_Array_Delete)
9250    return CheckOperatorDeleteDeclaration(*this, FnDecl);
9251
9252  if (Op == OO_New || Op == OO_Array_New)
9253    return CheckOperatorNewDeclaration(*this, FnDecl);
9254
9255  // C++ [over.oper]p6:
9256  //   An operator function shall either be a non-static member
9257  //   function or be a non-member function and have at least one
9258  //   parameter whose type is a class, a reference to a class, an
9259  //   enumeration, or a reference to an enumeration.
9260  if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) {
9261    if (MethodDecl->isStatic())
9262      return Diag(FnDecl->getLocation(),
9263                  diag::err_operator_overload_static) << FnDecl->getDeclName();
9264  } else {
9265    bool ClassOrEnumParam = false;
9266    for (FunctionDecl::param_iterator Param = FnDecl->param_begin(),
9267                                   ParamEnd = FnDecl->param_end();
9268         Param != ParamEnd; ++Param) {
9269      QualType ParamType = (*Param)->getType().getNonReferenceType();
9270      if (ParamType->isDependentType() || ParamType->isRecordType() ||
9271          ParamType->isEnumeralType()) {
9272        ClassOrEnumParam = true;
9273        break;
9274      }
9275    }
9276
9277    if (!ClassOrEnumParam)
9278      return Diag(FnDecl->getLocation(),
9279                  diag::err_operator_overload_needs_class_or_enum)
9280        << FnDecl->getDeclName();
9281  }
9282
9283  // C++ [over.oper]p8:
9284  //   An operator function cannot have default arguments (8.3.6),
9285  //   except where explicitly stated below.
9286  //
9287  // Only the function-call operator allows default arguments
9288  // (C++ [over.call]p1).
9289  if (Op != OO_Call) {
9290    for (FunctionDecl::param_iterator Param = FnDecl->param_begin();
9291         Param != FnDecl->param_end(); ++Param) {
9292      if ((*Param)->hasDefaultArg())
9293        return Diag((*Param)->getLocation(),
9294                    diag::err_operator_overload_default_arg)
9295          << FnDecl->getDeclName() << (*Param)->getDefaultArgRange();
9296    }
9297  }
9298
9299  static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = {
9300    { false, false, false }
9301#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
9302    , { Unary, Binary, MemberOnly }
9303#include "clang/Basic/OperatorKinds.def"
9304  };
9305
9306  bool CanBeUnaryOperator = OperatorUses[Op][0];
9307  bool CanBeBinaryOperator = OperatorUses[Op][1];
9308  bool MustBeMemberOperator = OperatorUses[Op][2];
9309
9310  // C++ [over.oper]p8:
9311  //   [...] Operator functions cannot have more or fewer parameters
9312  //   than the number required for the corresponding operator, as
9313  //   described in the rest of this subclause.
9314  unsigned NumParams = FnDecl->getNumParams()
9315                     + (isa<CXXMethodDecl>(FnDecl)? 1 : 0);
9316  if (Op != OO_Call &&
9317      ((NumParams == 1 && !CanBeUnaryOperator) ||
9318       (NumParams == 2 && !CanBeBinaryOperator) ||
9319       (NumParams < 1) || (NumParams > 2))) {
9320    // We have the wrong number of parameters.
9321    unsigned ErrorKind;
9322    if (CanBeUnaryOperator && CanBeBinaryOperator) {
9323      ErrorKind = 2;  // 2 -> unary or binary.
9324    } else if (CanBeUnaryOperator) {
9325      ErrorKind = 0;  // 0 -> unary
9326    } else {
9327      assert(CanBeBinaryOperator &&
9328             "All non-call overloaded operators are unary or binary!");
9329      ErrorKind = 1;  // 1 -> binary
9330    }
9331
9332    return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be)
9333      << FnDecl->getDeclName() << NumParams << ErrorKind;
9334  }
9335
9336  // Overloaded operators other than operator() cannot be variadic.
9337  if (Op != OO_Call &&
9338      FnDecl->getType()->getAs<FunctionProtoType>()->isVariadic()) {
9339    return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic)
9340      << FnDecl->getDeclName();
9341  }
9342
9343  // Some operators must be non-static member functions.
9344  if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) {
9345    return Diag(FnDecl->getLocation(),
9346                diag::err_operator_overload_must_be_member)
9347      << FnDecl->getDeclName();
9348  }
9349
9350  // C++ [over.inc]p1:
9351  //   The user-defined function called operator++ implements the
9352  //   prefix and postfix ++ operator. If this function is a member
9353  //   function with no parameters, or a non-member function with one
9354  //   parameter of class or enumeration type, it defines the prefix
9355  //   increment operator ++ for objects of that type. If the function
9356  //   is a member function with one parameter (which shall be of type
9357  //   int) or a non-member function with two parameters (the second
9358  //   of which shall be of type int), it defines the postfix
9359  //   increment operator ++ for objects of that type.
9360  if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) {
9361    ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1);
9362    bool ParamIsInt = false;
9363    if (const BuiltinType *BT = LastParam->getType()->getAs<BuiltinType>())
9364      ParamIsInt = BT->getKind() == BuiltinType::Int;
9365
9366    if (!ParamIsInt)
9367      return Diag(LastParam->getLocation(),
9368                  diag::err_operator_overload_post_incdec_must_be_int)
9369        << LastParam->getType() << (Op == OO_MinusMinus);
9370  }
9371
9372  return false;
9373}
9374
9375/// CheckLiteralOperatorDeclaration - Check whether the declaration
9376/// of this literal operator function is well-formed. If so, returns
9377/// false; otherwise, emits appropriate diagnostics and returns true.
9378bool Sema::CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl) {
9379  if (isa<CXXMethodDecl>(FnDecl)) {
9380    Diag(FnDecl->getLocation(), diag::err_literal_operator_outside_namespace)
9381      << FnDecl->getDeclName();
9382    return true;
9383  }
9384
9385  if (FnDecl->isExternC()) {
9386    Diag(FnDecl->getLocation(), diag::err_literal_operator_extern_c);
9387    return true;
9388  }
9389
9390  bool Valid = false;
9391
9392  // This might be the definition of a literal operator template.
9393  FunctionTemplateDecl *TpDecl = FnDecl->getDescribedFunctionTemplate();
9394  // This might be a specialization of a literal operator template.
9395  if (!TpDecl)
9396    TpDecl = FnDecl->getPrimaryTemplate();
9397
9398  // template <char...> type operator "" name() is the only valid template
9399  // signature, and the only valid signature with no parameters.
9400  if (TpDecl) {
9401    if (FnDecl->param_size() == 0) {
9402      // Must have only one template parameter
9403      TemplateParameterList *Params = TpDecl->getTemplateParameters();
9404      if (Params->size() == 1) {
9405        NonTypeTemplateParmDecl *PmDecl =
9406          cast<NonTypeTemplateParmDecl>(Params->getParam(0));
9407
9408        // The template parameter must be a char parameter pack.
9409        if (PmDecl && PmDecl->isTemplateParameterPack() &&
9410            Context.hasSameType(PmDecl->getType(), Context.CharTy))
9411          Valid = true;
9412      }
9413    }
9414  } else if (FnDecl->param_size()) {
9415    // Check the first parameter
9416    FunctionDecl::param_iterator Param = FnDecl->param_begin();
9417
9418    QualType T = (*Param)->getType().getUnqualifiedType();
9419
9420    // unsigned long long int, long double, and any character type are allowed
9421    // as the only parameters.
9422    if (Context.hasSameType(T, Context.UnsignedLongLongTy) ||
9423        Context.hasSameType(T, Context.LongDoubleTy) ||
9424        Context.hasSameType(T, Context.CharTy) ||
9425        Context.hasSameType(T, Context.WCharTy) ||
9426        Context.hasSameType(T, Context.Char16Ty) ||
9427        Context.hasSameType(T, Context.Char32Ty)) {
9428      if (++Param == FnDecl->param_end())
9429        Valid = true;
9430      goto FinishedParams;
9431    }
9432
9433    // Otherwise it must be a pointer to const; let's strip those qualifiers.
9434    const PointerType *PT = T->getAs<PointerType>();
9435    if (!PT)
9436      goto FinishedParams;
9437    T = PT->getPointeeType();
9438    if (!T.isConstQualified() || T.isVolatileQualified())
9439      goto FinishedParams;
9440    T = T.getUnqualifiedType();
9441
9442    // Move on to the second parameter;
9443    ++Param;
9444
9445    // If there is no second parameter, the first must be a const char *
9446    if (Param == FnDecl->param_end()) {
9447      if (Context.hasSameType(T, Context.CharTy))
9448        Valid = true;
9449      goto FinishedParams;
9450    }
9451
9452    // const char *, const wchar_t*, const char16_t*, and const char32_t*
9453    // are allowed as the first parameter to a two-parameter function
9454    if (!(Context.hasSameType(T, Context.CharTy) ||
9455          Context.hasSameType(T, Context.WCharTy) ||
9456          Context.hasSameType(T, Context.Char16Ty) ||
9457          Context.hasSameType(T, Context.Char32Ty)))
9458      goto FinishedParams;
9459
9460    // The second and final parameter must be an std::size_t
9461    T = (*Param)->getType().getUnqualifiedType();
9462    if (Context.hasSameType(T, Context.getSizeType()) &&
9463        ++Param == FnDecl->param_end())
9464      Valid = true;
9465  }
9466
9467  // FIXME: This diagnostic is absolutely terrible.
9468FinishedParams:
9469  if (!Valid) {
9470    Diag(FnDecl->getLocation(), diag::err_literal_operator_params)
9471      << FnDecl->getDeclName();
9472    return true;
9473  }
9474
9475  // A parameter-declaration-clause containing a default argument is not
9476  // equivalent to any of the permitted forms.
9477  for (FunctionDecl::param_iterator Param = FnDecl->param_begin(),
9478                                    ParamEnd = FnDecl->param_end();
9479       Param != ParamEnd; ++Param) {
9480    if ((*Param)->hasDefaultArg()) {
9481      Diag((*Param)->getDefaultArgRange().getBegin(),
9482           diag::err_literal_operator_default_argument)
9483        << (*Param)->getDefaultArgRange();
9484      break;
9485    }
9486  }
9487
9488  StringRef LiteralName
9489    = FnDecl->getDeclName().getCXXLiteralIdentifier()->getName();
9490  if (LiteralName[0] != '_') {
9491    // C++11 [usrlit.suffix]p1:
9492    //   Literal suffix identifiers that do not start with an underscore
9493    //   are reserved for future standardization.
9494    Diag(FnDecl->getLocation(), diag::warn_user_literal_reserved);
9495  }
9496
9497  return false;
9498}
9499
9500/// ActOnStartLinkageSpecification - Parsed the beginning of a C++
9501/// linkage specification, including the language and (if present)
9502/// the '{'. ExternLoc is the location of the 'extern', LangLoc is
9503/// the location of the language string literal, which is provided
9504/// by Lang/StrSize. LBraceLoc, if valid, provides the location of
9505/// the '{' brace. Otherwise, this linkage specification does not
9506/// have any braces.
9507Decl *Sema::ActOnStartLinkageSpecification(Scope *S, SourceLocation ExternLoc,
9508                                           SourceLocation LangLoc,
9509                                           StringRef Lang,
9510                                           SourceLocation LBraceLoc) {
9511  LinkageSpecDecl::LanguageIDs Language;
9512  if (Lang == "\"C\"")
9513    Language = LinkageSpecDecl::lang_c;
9514  else if (Lang == "\"C++\"")
9515    Language = LinkageSpecDecl::lang_cxx;
9516  else {
9517    Diag(LangLoc, diag::err_bad_language);
9518    return 0;
9519  }
9520
9521  // FIXME: Add all the various semantics of linkage specifications
9522
9523  LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext,
9524                                               ExternLoc, LangLoc, Language);
9525  CurContext->addDecl(D);
9526  PushDeclContext(S, D);
9527  return D;
9528}
9529
9530/// ActOnFinishLinkageSpecification - Complete the definition of
9531/// the C++ linkage specification LinkageSpec. If RBraceLoc is
9532/// valid, it's the position of the closing '}' brace in a linkage
9533/// specification that uses braces.
9534Decl *Sema::ActOnFinishLinkageSpecification(Scope *S,
9535                                            Decl *LinkageSpec,
9536                                            SourceLocation RBraceLoc) {
9537  if (LinkageSpec) {
9538    if (RBraceLoc.isValid()) {
9539      LinkageSpecDecl* LSDecl = cast<LinkageSpecDecl>(LinkageSpec);
9540      LSDecl->setRBraceLoc(RBraceLoc);
9541    }
9542    PopDeclContext();
9543  }
9544  return LinkageSpec;
9545}
9546
9547/// \brief Perform semantic analysis for the variable declaration that
9548/// occurs within a C++ catch clause, returning the newly-created
9549/// variable.
9550VarDecl *Sema::BuildExceptionDeclaration(Scope *S,
9551                                         TypeSourceInfo *TInfo,
9552                                         SourceLocation StartLoc,
9553                                         SourceLocation Loc,
9554                                         IdentifierInfo *Name) {
9555  bool Invalid = false;
9556  QualType ExDeclType = TInfo->getType();
9557
9558  // Arrays and functions decay.
9559  if (ExDeclType->isArrayType())
9560    ExDeclType = Context.getArrayDecayedType(ExDeclType);
9561  else if (ExDeclType->isFunctionType())
9562    ExDeclType = Context.getPointerType(ExDeclType);
9563
9564  // C++ 15.3p1: The exception-declaration shall not denote an incomplete type.
9565  // The exception-declaration shall not denote a pointer or reference to an
9566  // incomplete type, other than [cv] void*.
9567  // N2844 forbids rvalue references.
9568  if (!ExDeclType->isDependentType() && ExDeclType->isRValueReferenceType()) {
9569    Diag(Loc, diag::err_catch_rvalue_ref);
9570    Invalid = true;
9571  }
9572
9573  QualType BaseType = ExDeclType;
9574  int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference
9575  unsigned DK = diag::err_catch_incomplete;
9576  if (const PointerType *Ptr = BaseType->getAs<PointerType>()) {
9577    BaseType = Ptr->getPointeeType();
9578    Mode = 1;
9579    DK = diag::err_catch_incomplete_ptr;
9580  } else if (const ReferenceType *Ref = BaseType->getAs<ReferenceType>()) {
9581    // For the purpose of error recovery, we treat rvalue refs like lvalue refs.
9582    BaseType = Ref->getPointeeType();
9583    Mode = 2;
9584    DK = diag::err_catch_incomplete_ref;
9585  }
9586  if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) &&
9587      !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK))
9588    Invalid = true;
9589
9590  if (!Invalid && !ExDeclType->isDependentType() &&
9591      RequireNonAbstractType(Loc, ExDeclType,
9592                             diag::err_abstract_type_in_decl,
9593                             AbstractVariableType))
9594    Invalid = true;
9595
9596  // Only the non-fragile NeXT runtime currently supports C++ catches
9597  // of ObjC types, and no runtime supports catching ObjC types by value.
9598  if (!Invalid && getLangOpts().ObjC1) {
9599    QualType T = ExDeclType;
9600    if (const ReferenceType *RT = T->getAs<ReferenceType>())
9601      T = RT->getPointeeType();
9602
9603    if (T->isObjCObjectType()) {
9604      Diag(Loc, diag::err_objc_object_catch);
9605      Invalid = true;
9606    } else if (T->isObjCObjectPointerType()) {
9607      if (!getLangOpts().ObjCNonFragileABI)
9608        Diag(Loc, diag::warn_objc_pointer_cxx_catch_fragile);
9609    }
9610  }
9611
9612  VarDecl *ExDecl = VarDecl::Create(Context, CurContext, StartLoc, Loc, Name,
9613                                    ExDeclType, TInfo, SC_None, SC_None);
9614  ExDecl->setExceptionVariable(true);
9615
9616  // In ARC, infer 'retaining' for variables of retainable type.
9617  if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(ExDecl))
9618    Invalid = true;
9619
9620  if (!Invalid && !ExDeclType->isDependentType()) {
9621    if (const RecordType *recordType = ExDeclType->getAs<RecordType>()) {
9622      // C++ [except.handle]p16:
9623      //   The object declared in an exception-declaration or, if the
9624      //   exception-declaration does not specify a name, a temporary (12.2) is
9625      //   copy-initialized (8.5) from the exception object. [...]
9626      //   The object is destroyed when the handler exits, after the destruction
9627      //   of any automatic objects initialized within the handler.
9628      //
9629      // We just pretend to initialize the object with itself, then make sure
9630      // it can be destroyed later.
9631      QualType initType = ExDeclType;
9632
9633      InitializedEntity entity =
9634        InitializedEntity::InitializeVariable(ExDecl);
9635      InitializationKind initKind =
9636        InitializationKind::CreateCopy(Loc, SourceLocation());
9637
9638      Expr *opaqueValue =
9639        new (Context) OpaqueValueExpr(Loc, initType, VK_LValue, OK_Ordinary);
9640      InitializationSequence sequence(*this, entity, initKind, &opaqueValue, 1);
9641      ExprResult result = sequence.Perform(*this, entity, initKind,
9642                                           MultiExprArg(&opaqueValue, 1));
9643      if (result.isInvalid())
9644        Invalid = true;
9645      else {
9646        // If the constructor used was non-trivial, set this as the
9647        // "initializer".
9648        CXXConstructExpr *construct = cast<CXXConstructExpr>(result.take());
9649        if (!construct->getConstructor()->isTrivial()) {
9650          Expr *init = MaybeCreateExprWithCleanups(construct);
9651          ExDecl->setInit(init);
9652        }
9653
9654        // And make sure it's destructable.
9655        FinalizeVarWithDestructor(ExDecl, recordType);
9656      }
9657    }
9658  }
9659
9660  if (Invalid)
9661    ExDecl->setInvalidDecl();
9662
9663  return ExDecl;
9664}
9665
9666/// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch
9667/// handler.
9668Decl *Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D) {
9669  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
9670  bool Invalid = D.isInvalidType();
9671
9672  // Check for unexpanded parameter packs.
9673  if (TInfo && DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
9674                                               UPPC_ExceptionType)) {
9675    TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
9676                                             D.getIdentifierLoc());
9677    Invalid = true;
9678  }
9679
9680  IdentifierInfo *II = D.getIdentifier();
9681  if (NamedDecl *PrevDecl = LookupSingleName(S, II, D.getIdentifierLoc(),
9682                                             LookupOrdinaryName,
9683                                             ForRedeclaration)) {
9684    // The scope should be freshly made just for us. There is just no way
9685    // it contains any previous declaration.
9686    assert(!S->isDeclScope(PrevDecl));
9687    if (PrevDecl->isTemplateParameter()) {
9688      // Maybe we will complain about the shadowed template parameter.
9689      DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
9690      PrevDecl = 0;
9691    }
9692  }
9693
9694  if (D.getCXXScopeSpec().isSet() && !Invalid) {
9695    Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator)
9696      << D.getCXXScopeSpec().getRange();
9697    Invalid = true;
9698  }
9699
9700  VarDecl *ExDecl = BuildExceptionDeclaration(S, TInfo,
9701                                              D.getLocStart(),
9702                                              D.getIdentifierLoc(),
9703                                              D.getIdentifier());
9704  if (Invalid)
9705    ExDecl->setInvalidDecl();
9706
9707  // Add the exception declaration into this scope.
9708  if (II)
9709    PushOnScopeChains(ExDecl, S);
9710  else
9711    CurContext->addDecl(ExDecl);
9712
9713  ProcessDeclAttributes(S, ExDecl, D);
9714  return ExDecl;
9715}
9716
9717Decl *Sema::ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,
9718                                         Expr *AssertExpr,
9719                                         Expr *AssertMessageExpr_,
9720                                         SourceLocation RParenLoc) {
9721  StringLiteral *AssertMessage = cast<StringLiteral>(AssertMessageExpr_);
9722
9723  if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent()) {
9724    // In a static_assert-declaration, the constant-expression shall be a
9725    // constant expression that can be contextually converted to bool.
9726    ExprResult Converted = PerformContextuallyConvertToBool(AssertExpr);
9727    if (Converted.isInvalid())
9728      return 0;
9729
9730    llvm::APSInt Cond;
9731    if (VerifyIntegerConstantExpression(Converted.get(), &Cond,
9732          diag::err_static_assert_expression_is_not_constant,
9733          /*AllowFold=*/false).isInvalid())
9734      return 0;
9735
9736    if (!Cond) {
9737      llvm::SmallString<256> MsgBuffer;
9738      llvm::raw_svector_ostream Msg(MsgBuffer);
9739      AssertMessage->printPretty(Msg, Context, 0, getPrintingPolicy());
9740      Diag(StaticAssertLoc, diag::err_static_assert_failed)
9741        << Msg.str() << AssertExpr->getSourceRange();
9742    }
9743  }
9744
9745  if (DiagnoseUnexpandedParameterPack(AssertExpr, UPPC_StaticAssertExpression))
9746    return 0;
9747
9748  Decl *Decl = StaticAssertDecl::Create(Context, CurContext, StaticAssertLoc,
9749                                        AssertExpr, AssertMessage, RParenLoc);
9750
9751  CurContext->addDecl(Decl);
9752  return Decl;
9753}
9754
9755/// \brief Perform semantic analysis of the given friend type declaration.
9756///
9757/// \returns A friend declaration that.
9758FriendDecl *Sema::CheckFriendTypeDecl(SourceLocation Loc,
9759                                      SourceLocation FriendLoc,
9760                                      TypeSourceInfo *TSInfo) {
9761  assert(TSInfo && "NULL TypeSourceInfo for friend type declaration");
9762
9763  QualType T = TSInfo->getType();
9764  SourceRange TypeRange = TSInfo->getTypeLoc().getLocalSourceRange();
9765
9766  // C++03 [class.friend]p2:
9767  //   An elaborated-type-specifier shall be used in a friend declaration
9768  //   for a class.*
9769  //
9770  //   * The class-key of the elaborated-type-specifier is required.
9771  if (!ActiveTemplateInstantiations.empty()) {
9772    // Do not complain about the form of friend template types during
9773    // template instantiation; we will already have complained when the
9774    // template was declared.
9775  } else if (!T->isElaboratedTypeSpecifier()) {
9776    // If we evaluated the type to a record type, suggest putting
9777    // a tag in front.
9778    if (const RecordType *RT = T->getAs<RecordType>()) {
9779      RecordDecl *RD = RT->getDecl();
9780
9781      std::string InsertionText = std::string(" ") + RD->getKindName();
9782
9783      Diag(TypeRange.getBegin(),
9784           getLangOpts().CPlusPlus0x ?
9785             diag::warn_cxx98_compat_unelaborated_friend_type :
9786             diag::ext_unelaborated_friend_type)
9787        << (unsigned) RD->getTagKind()
9788        << T
9789        << FixItHint::CreateInsertion(PP.getLocForEndOfToken(FriendLoc),
9790                                      InsertionText);
9791    } else {
9792      Diag(FriendLoc,
9793           getLangOpts().CPlusPlus0x ?
9794             diag::warn_cxx98_compat_nonclass_type_friend :
9795             diag::ext_nonclass_type_friend)
9796        << T
9797        << SourceRange(FriendLoc, TypeRange.getEnd());
9798    }
9799  } else if (T->getAs<EnumType>()) {
9800    Diag(FriendLoc,
9801         getLangOpts().CPlusPlus0x ?
9802           diag::warn_cxx98_compat_enum_friend :
9803           diag::ext_enum_friend)
9804      << T
9805      << SourceRange(FriendLoc, TypeRange.getEnd());
9806  }
9807
9808  // C++0x [class.friend]p3:
9809  //   If the type specifier in a friend declaration designates a (possibly
9810  //   cv-qualified) class type, that class is declared as a friend; otherwise,
9811  //   the friend declaration is ignored.
9812
9813  // FIXME: C++0x has some syntactic restrictions on friend type declarations
9814  // in [class.friend]p3 that we do not implement.
9815
9816  return FriendDecl::Create(Context, CurContext, Loc, TSInfo, FriendLoc);
9817}
9818
9819/// Handle a friend tag declaration where the scope specifier was
9820/// templated.
9821Decl *Sema::ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc,
9822                                    unsigned TagSpec, SourceLocation TagLoc,
9823                                    CXXScopeSpec &SS,
9824                                    IdentifierInfo *Name, SourceLocation NameLoc,
9825                                    AttributeList *Attr,
9826                                    MultiTemplateParamsArg TempParamLists) {
9827  TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
9828
9829  bool isExplicitSpecialization = false;
9830  bool Invalid = false;
9831
9832  if (TemplateParameterList *TemplateParams
9833        = MatchTemplateParametersToScopeSpecifier(TagLoc, NameLoc, SS,
9834                                                  TempParamLists.get(),
9835                                                  TempParamLists.size(),
9836                                                  /*friend*/ true,
9837                                                  isExplicitSpecialization,
9838                                                  Invalid)) {
9839    if (TemplateParams->size() > 0) {
9840      // This is a declaration of a class template.
9841      if (Invalid)
9842        return 0;
9843
9844      return CheckClassTemplate(S, TagSpec, TUK_Friend, TagLoc,
9845                                SS, Name, NameLoc, Attr,
9846                                TemplateParams, AS_public,
9847                                /*ModulePrivateLoc=*/SourceLocation(),
9848                                TempParamLists.size() - 1,
9849                   (TemplateParameterList**) TempParamLists.release()).take();
9850    } else {
9851      // The "template<>" header is extraneous.
9852      Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams)
9853        << TypeWithKeyword::getTagTypeKindName(Kind) << Name;
9854      isExplicitSpecialization = true;
9855    }
9856  }
9857
9858  if (Invalid) return 0;
9859
9860  bool isAllExplicitSpecializations = true;
9861  for (unsigned I = TempParamLists.size(); I-- > 0; ) {
9862    if (TempParamLists.get()[I]->size()) {
9863      isAllExplicitSpecializations = false;
9864      break;
9865    }
9866  }
9867
9868  // FIXME: don't ignore attributes.
9869
9870  // If it's explicit specializations all the way down, just forget
9871  // about the template header and build an appropriate non-templated
9872  // friend.  TODO: for source fidelity, remember the headers.
9873  if (isAllExplicitSpecializations) {
9874    if (SS.isEmpty()) {
9875      bool Owned = false;
9876      bool IsDependent = false;
9877      return ActOnTag(S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc,
9878                      Attr, AS_public,
9879                      /*ModulePrivateLoc=*/SourceLocation(),
9880                      MultiTemplateParamsArg(), Owned, IsDependent,
9881                      /*ScopedEnumKWLoc=*/SourceLocation(),
9882                      /*ScopedEnumUsesClassTag=*/false,
9883                      /*UnderlyingType=*/TypeResult());
9884    }
9885
9886    NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
9887    ElaboratedTypeKeyword Keyword
9888      = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
9889    QualType T = CheckTypenameType(Keyword, TagLoc, QualifierLoc,
9890                                   *Name, NameLoc);
9891    if (T.isNull())
9892      return 0;
9893
9894    TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
9895    if (isa<DependentNameType>(T)) {
9896      DependentNameTypeLoc TL = cast<DependentNameTypeLoc>(TSI->getTypeLoc());
9897      TL.setElaboratedKeywordLoc(TagLoc);
9898      TL.setQualifierLoc(QualifierLoc);
9899      TL.setNameLoc(NameLoc);
9900    } else {
9901      ElaboratedTypeLoc TL = cast<ElaboratedTypeLoc>(TSI->getTypeLoc());
9902      TL.setElaboratedKeywordLoc(TagLoc);
9903      TL.setQualifierLoc(QualifierLoc);
9904      cast<TypeSpecTypeLoc>(TL.getNamedTypeLoc()).setNameLoc(NameLoc);
9905    }
9906
9907    FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
9908                                            TSI, FriendLoc);
9909    Friend->setAccess(AS_public);
9910    CurContext->addDecl(Friend);
9911    return Friend;
9912  }
9913
9914  assert(SS.isNotEmpty() && "valid templated tag with no SS and no direct?");
9915
9916
9917
9918  // Handle the case of a templated-scope friend class.  e.g.
9919  //   template <class T> class A<T>::B;
9920  // FIXME: we don't support these right now.
9921  ElaboratedTypeKeyword ETK = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
9922  QualType T = Context.getDependentNameType(ETK, SS.getScopeRep(), Name);
9923  TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
9924  DependentNameTypeLoc TL = cast<DependentNameTypeLoc>(TSI->getTypeLoc());
9925  TL.setElaboratedKeywordLoc(TagLoc);
9926  TL.setQualifierLoc(SS.getWithLocInContext(Context));
9927  TL.setNameLoc(NameLoc);
9928
9929  FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
9930                                          TSI, FriendLoc);
9931  Friend->setAccess(AS_public);
9932  Friend->setUnsupportedFriend(true);
9933  CurContext->addDecl(Friend);
9934  return Friend;
9935}
9936
9937
9938/// Handle a friend type declaration.  This works in tandem with
9939/// ActOnTag.
9940///
9941/// Notes on friend class templates:
9942///
9943/// We generally treat friend class declarations as if they were
9944/// declaring a class.  So, for example, the elaborated type specifier
9945/// in a friend declaration is required to obey the restrictions of a
9946/// class-head (i.e. no typedefs in the scope chain), template
9947/// parameters are required to match up with simple template-ids, &c.
9948/// However, unlike when declaring a template specialization, it's
9949/// okay to refer to a template specialization without an empty
9950/// template parameter declaration, e.g.
9951///   friend class A<T>::B<unsigned>;
9952/// We permit this as a special case; if there are any template
9953/// parameters present at all, require proper matching, i.e.
9954///   template <> template <class T> friend class A<int>::B;
9955Decl *Sema::ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS,
9956                                MultiTemplateParamsArg TempParams) {
9957  SourceLocation Loc = DS.getLocStart();
9958
9959  assert(DS.isFriendSpecified());
9960  assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
9961
9962  // Try to convert the decl specifier to a type.  This works for
9963  // friend templates because ActOnTag never produces a ClassTemplateDecl
9964  // for a TUK_Friend.
9965  Declarator TheDeclarator(DS, Declarator::MemberContext);
9966  TypeSourceInfo *TSI = GetTypeForDeclarator(TheDeclarator, S);
9967  QualType T = TSI->getType();
9968  if (TheDeclarator.isInvalidType())
9969    return 0;
9970
9971  if (DiagnoseUnexpandedParameterPack(Loc, TSI, UPPC_FriendDeclaration))
9972    return 0;
9973
9974  // This is definitely an error in C++98.  It's probably meant to
9975  // be forbidden in C++0x, too, but the specification is just
9976  // poorly written.
9977  //
9978  // The problem is with declarations like the following:
9979  //   template <T> friend A<T>::foo;
9980  // where deciding whether a class C is a friend or not now hinges
9981  // on whether there exists an instantiation of A that causes
9982  // 'foo' to equal C.  There are restrictions on class-heads
9983  // (which we declare (by fiat) elaborated friend declarations to
9984  // be) that makes this tractable.
9985  //
9986  // FIXME: handle "template <> friend class A<T>;", which
9987  // is possibly well-formed?  Who even knows?
9988  if (TempParams.size() && !T->isElaboratedTypeSpecifier()) {
9989    Diag(Loc, diag::err_tagless_friend_type_template)
9990      << DS.getSourceRange();
9991    return 0;
9992  }
9993
9994  // C++98 [class.friend]p1: A friend of a class is a function
9995  //   or class that is not a member of the class . . .
9996  // This is fixed in DR77, which just barely didn't make the C++03
9997  // deadline.  It's also a very silly restriction that seriously
9998  // affects inner classes and which nobody else seems to implement;
9999  // thus we never diagnose it, not even in -pedantic.
10000  //
10001  // But note that we could warn about it: it's always useless to
10002  // friend one of your own members (it's not, however, worthless to
10003  // friend a member of an arbitrary specialization of your template).
10004
10005  Decl *D;
10006  if (unsigned NumTempParamLists = TempParams.size())
10007    D = FriendTemplateDecl::Create(Context, CurContext, Loc,
10008                                   NumTempParamLists,
10009                                   TempParams.release(),
10010                                   TSI,
10011                                   DS.getFriendSpecLoc());
10012  else
10013    D = CheckFriendTypeDecl(Loc, DS.getFriendSpecLoc(), TSI);
10014
10015  if (!D)
10016    return 0;
10017
10018  D->setAccess(AS_public);
10019  CurContext->addDecl(D);
10020
10021  return D;
10022}
10023
10024Decl *Sema::ActOnFriendFunctionDecl(Scope *S, Declarator &D,
10025                                    MultiTemplateParamsArg TemplateParams) {
10026  const DeclSpec &DS = D.getDeclSpec();
10027
10028  assert(DS.isFriendSpecified());
10029  assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
10030
10031  SourceLocation Loc = D.getIdentifierLoc();
10032  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
10033
10034  // C++ [class.friend]p1
10035  //   A friend of a class is a function or class....
10036  // Note that this sees through typedefs, which is intended.
10037  // It *doesn't* see through dependent types, which is correct
10038  // according to [temp.arg.type]p3:
10039  //   If a declaration acquires a function type through a
10040  //   type dependent on a template-parameter and this causes
10041  //   a declaration that does not use the syntactic form of a
10042  //   function declarator to have a function type, the program
10043  //   is ill-formed.
10044  if (!TInfo->getType()->isFunctionType()) {
10045    Diag(Loc, diag::err_unexpected_friend);
10046
10047    // It might be worthwhile to try to recover by creating an
10048    // appropriate declaration.
10049    return 0;
10050  }
10051
10052  // C++ [namespace.memdef]p3
10053  //  - If a friend declaration in a non-local class first declares a
10054  //    class or function, the friend class or function is a member
10055  //    of the innermost enclosing namespace.
10056  //  - The name of the friend is not found by simple name lookup
10057  //    until a matching declaration is provided in that namespace
10058  //    scope (either before or after the class declaration granting
10059  //    friendship).
10060  //  - If a friend function is called, its name may be found by the
10061  //    name lookup that considers functions from namespaces and
10062  //    classes associated with the types of the function arguments.
10063  //  - When looking for a prior declaration of a class or a function
10064  //    declared as a friend, scopes outside the innermost enclosing
10065  //    namespace scope are not considered.
10066
10067  CXXScopeSpec &SS = D.getCXXScopeSpec();
10068  DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
10069  DeclarationName Name = NameInfo.getName();
10070  assert(Name);
10071
10072  // Check for unexpanded parameter packs.
10073  if (DiagnoseUnexpandedParameterPack(Loc, TInfo, UPPC_FriendDeclaration) ||
10074      DiagnoseUnexpandedParameterPack(NameInfo, UPPC_FriendDeclaration) ||
10075      DiagnoseUnexpandedParameterPack(SS, UPPC_FriendDeclaration))
10076    return 0;
10077
10078  // The context we found the declaration in, or in which we should
10079  // create the declaration.
10080  DeclContext *DC;
10081  Scope *DCScope = S;
10082  LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
10083                        ForRedeclaration);
10084
10085  // FIXME: there are different rules in local classes
10086
10087  // There are four cases here.
10088  //   - There's no scope specifier, in which case we just go to the
10089  //     appropriate scope and look for a function or function template
10090  //     there as appropriate.
10091  // Recover from invalid scope qualifiers as if they just weren't there.
10092  if (SS.isInvalid() || !SS.isSet()) {
10093    // C++0x [namespace.memdef]p3:
10094    //   If the name in a friend declaration is neither qualified nor
10095    //   a template-id and the declaration is a function or an
10096    //   elaborated-type-specifier, the lookup to determine whether
10097    //   the entity has been previously declared shall not consider
10098    //   any scopes outside the innermost enclosing namespace.
10099    // C++0x [class.friend]p11:
10100    //   If a friend declaration appears in a local class and the name
10101    //   specified is an unqualified name, a prior declaration is
10102    //   looked up without considering scopes that are outside the
10103    //   innermost enclosing non-class scope. For a friend function
10104    //   declaration, if there is no prior declaration, the program is
10105    //   ill-formed.
10106    bool isLocal = cast<CXXRecordDecl>(CurContext)->isLocalClass();
10107    bool isTemplateId = D.getName().getKind() == UnqualifiedId::IK_TemplateId;
10108
10109    // Find the appropriate context according to the above.
10110    DC = CurContext;
10111    while (true) {
10112      // Skip class contexts.  If someone can cite chapter and verse
10113      // for this behavior, that would be nice --- it's what GCC and
10114      // EDG do, and it seems like a reasonable intent, but the spec
10115      // really only says that checks for unqualified existing
10116      // declarations should stop at the nearest enclosing namespace,
10117      // not that they should only consider the nearest enclosing
10118      // namespace.
10119      while (DC->isRecord() || DC->isTransparentContext())
10120        DC = DC->getParent();
10121
10122      LookupQualifiedName(Previous, DC);
10123
10124      // TODO: decide what we think about using declarations.
10125      if (isLocal || !Previous.empty())
10126        break;
10127
10128      if (isTemplateId) {
10129        if (isa<TranslationUnitDecl>(DC)) break;
10130      } else {
10131        if (DC->isFileContext()) break;
10132      }
10133      DC = DC->getParent();
10134    }
10135
10136    // C++ [class.friend]p1: A friend of a class is a function or
10137    //   class that is not a member of the class . . .
10138    // C++11 changes this for both friend types and functions.
10139    // Most C++ 98 compilers do seem to give an error here, so
10140    // we do, too.
10141    if (!Previous.empty() && DC->Equals(CurContext))
10142      Diag(DS.getFriendSpecLoc(),
10143           getLangOpts().CPlusPlus0x ?
10144             diag::warn_cxx98_compat_friend_is_member :
10145             diag::err_friend_is_member);
10146
10147    DCScope = getScopeForDeclContext(S, DC);
10148
10149    // C++ [class.friend]p6:
10150    //   A function can be defined in a friend declaration of a class if and
10151    //   only if the class is a non-local class (9.8), the function name is
10152    //   unqualified, and the function has namespace scope.
10153    if (isLocal && D.isFunctionDefinition()) {
10154      Diag(NameInfo.getBeginLoc(), diag::err_friend_def_in_local_class);
10155    }
10156
10157  //   - There's a non-dependent scope specifier, in which case we
10158  //     compute it and do a previous lookup there for a function
10159  //     or function template.
10160  } else if (!SS.getScopeRep()->isDependent()) {
10161    DC = computeDeclContext(SS);
10162    if (!DC) return 0;
10163
10164    if (RequireCompleteDeclContext(SS, DC)) return 0;
10165
10166    LookupQualifiedName(Previous, DC);
10167
10168    // Ignore things found implicitly in the wrong scope.
10169    // TODO: better diagnostics for this case.  Suggesting the right
10170    // qualified scope would be nice...
10171    LookupResult::Filter F = Previous.makeFilter();
10172    while (F.hasNext()) {
10173      NamedDecl *D = F.next();
10174      if (!DC->InEnclosingNamespaceSetOf(
10175              D->getDeclContext()->getRedeclContext()))
10176        F.erase();
10177    }
10178    F.done();
10179
10180    if (Previous.empty()) {
10181      D.setInvalidType();
10182      Diag(Loc, diag::err_qualified_friend_not_found)
10183          << Name << TInfo->getType();
10184      return 0;
10185    }
10186
10187    // C++ [class.friend]p1: A friend of a class is a function or
10188    //   class that is not a member of the class . . .
10189    if (DC->Equals(CurContext))
10190      Diag(DS.getFriendSpecLoc(),
10191           getLangOpts().CPlusPlus0x ?
10192             diag::warn_cxx98_compat_friend_is_member :
10193             diag::err_friend_is_member);
10194
10195    if (D.isFunctionDefinition()) {
10196      // C++ [class.friend]p6:
10197      //   A function can be defined in a friend declaration of a class if and
10198      //   only if the class is a non-local class (9.8), the function name is
10199      //   unqualified, and the function has namespace scope.
10200      SemaDiagnosticBuilder DB
10201        = Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def);
10202
10203      DB << SS.getScopeRep();
10204      if (DC->isFileContext())
10205        DB << FixItHint::CreateRemoval(SS.getRange());
10206      SS.clear();
10207    }
10208
10209  //   - There's a scope specifier that does not match any template
10210  //     parameter lists, in which case we use some arbitrary context,
10211  //     create a method or method template, and wait for instantiation.
10212  //   - There's a scope specifier that does match some template
10213  //     parameter lists, which we don't handle right now.
10214  } else {
10215    if (D.isFunctionDefinition()) {
10216      // C++ [class.friend]p6:
10217      //   A function can be defined in a friend declaration of a class if and
10218      //   only if the class is a non-local class (9.8), the function name is
10219      //   unqualified, and the function has namespace scope.
10220      Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def)
10221        << SS.getScopeRep();
10222    }
10223
10224    DC = CurContext;
10225    assert(isa<CXXRecordDecl>(DC) && "friend declaration not in class?");
10226  }
10227
10228  if (!DC->isRecord()) {
10229    // This implies that it has to be an operator or function.
10230    if (D.getName().getKind() == UnqualifiedId::IK_ConstructorName ||
10231        D.getName().getKind() == UnqualifiedId::IK_DestructorName ||
10232        D.getName().getKind() == UnqualifiedId::IK_ConversionFunctionId) {
10233      Diag(Loc, diag::err_introducing_special_friend) <<
10234        (D.getName().getKind() == UnqualifiedId::IK_ConstructorName ? 0 :
10235         D.getName().getKind() == UnqualifiedId::IK_DestructorName ? 1 : 2);
10236      return 0;
10237    }
10238  }
10239
10240  // FIXME: This is an egregious hack to cope with cases where the scope stack
10241  // does not contain the declaration context, i.e., in an out-of-line
10242  // definition of a class.
10243  Scope FakeDCScope(S, Scope::DeclScope, Diags);
10244  if (!DCScope) {
10245    FakeDCScope.setEntity(DC);
10246    DCScope = &FakeDCScope;
10247  }
10248
10249  bool AddToScope = true;
10250  NamedDecl *ND = ActOnFunctionDeclarator(DCScope, D, DC, TInfo, Previous,
10251                                          move(TemplateParams), AddToScope);
10252  if (!ND) return 0;
10253
10254  assert(ND->getDeclContext() == DC);
10255  assert(ND->getLexicalDeclContext() == CurContext);
10256
10257  // Add the function declaration to the appropriate lookup tables,
10258  // adjusting the redeclarations list as necessary.  We don't
10259  // want to do this yet if the friending class is dependent.
10260  //
10261  // Also update the scope-based lookup if the target context's
10262  // lookup context is in lexical scope.
10263  if (!CurContext->isDependentContext()) {
10264    DC = DC->getRedeclContext();
10265    DC->makeDeclVisibleInContext(ND);
10266    if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
10267      PushOnScopeChains(ND, EnclosingScope, /*AddToContext=*/ false);
10268  }
10269
10270  FriendDecl *FrD = FriendDecl::Create(Context, CurContext,
10271                                       D.getIdentifierLoc(), ND,
10272                                       DS.getFriendSpecLoc());
10273  FrD->setAccess(AS_public);
10274  CurContext->addDecl(FrD);
10275
10276  if (ND->isInvalidDecl())
10277    FrD->setInvalidDecl();
10278  else {
10279    FunctionDecl *FD;
10280    if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
10281      FD = FTD->getTemplatedDecl();
10282    else
10283      FD = cast<FunctionDecl>(ND);
10284
10285    // Mark templated-scope function declarations as unsupported.
10286    if (FD->getNumTemplateParameterLists())
10287      FrD->setUnsupportedFriend(true);
10288  }
10289
10290  return ND;
10291}
10292
10293void Sema::SetDeclDeleted(Decl *Dcl, SourceLocation DelLoc) {
10294  AdjustDeclIfTemplate(Dcl);
10295
10296  FunctionDecl *Fn = dyn_cast<FunctionDecl>(Dcl);
10297  if (!Fn) {
10298    Diag(DelLoc, diag::err_deleted_non_function);
10299    return;
10300  }
10301  if (const FunctionDecl *Prev = Fn->getPreviousDecl()) {
10302    Diag(DelLoc, diag::err_deleted_decl_not_first);
10303    Diag(Prev->getLocation(), diag::note_previous_declaration);
10304    // If the declaration wasn't the first, we delete the function anyway for
10305    // recovery.
10306  }
10307  Fn->setDeletedAsWritten();
10308
10309  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Dcl);
10310  if (!MD)
10311    return;
10312
10313  // A deleted special member function is trivial if the corresponding
10314  // implicitly-declared function would have been.
10315  switch (getSpecialMember(MD)) {
10316  case CXXInvalid:
10317    break;
10318  case CXXDefaultConstructor:
10319    MD->setTrivial(MD->getParent()->hasTrivialDefaultConstructor());
10320    break;
10321  case CXXCopyConstructor:
10322    MD->setTrivial(MD->getParent()->hasTrivialCopyConstructor());
10323    break;
10324  case CXXMoveConstructor:
10325    MD->setTrivial(MD->getParent()->hasTrivialMoveConstructor());
10326    break;
10327  case CXXCopyAssignment:
10328    MD->setTrivial(MD->getParent()->hasTrivialCopyAssignment());
10329    break;
10330  case CXXMoveAssignment:
10331    MD->setTrivial(MD->getParent()->hasTrivialMoveAssignment());
10332    break;
10333  case CXXDestructor:
10334    MD->setTrivial(MD->getParent()->hasTrivialDestructor());
10335    break;
10336  }
10337}
10338
10339void Sema::SetDeclDefaulted(Decl *Dcl, SourceLocation DefaultLoc) {
10340  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Dcl);
10341
10342  if (MD) {
10343    if (MD->getParent()->isDependentType()) {
10344      MD->setDefaulted();
10345      MD->setExplicitlyDefaulted();
10346      return;
10347    }
10348
10349    CXXSpecialMember Member = getSpecialMember(MD);
10350    if (Member == CXXInvalid) {
10351      Diag(DefaultLoc, diag::err_default_special_members);
10352      return;
10353    }
10354
10355    MD->setDefaulted();
10356    MD->setExplicitlyDefaulted();
10357
10358    // If this definition appears within the record, do the checking when
10359    // the record is complete.
10360    const FunctionDecl *Primary = MD;
10361    if (MD->getTemplatedKind() != FunctionDecl::TK_NonTemplate)
10362      // Find the uninstantiated declaration that actually had the '= default'
10363      // on it.
10364      MD->getTemplateInstantiationPattern()->isDefined(Primary);
10365
10366    if (Primary == Primary->getCanonicalDecl())
10367      return;
10368
10369    switch (Member) {
10370    case CXXDefaultConstructor: {
10371      CXXConstructorDecl *CD = cast<CXXConstructorDecl>(MD);
10372      CheckExplicitlyDefaultedSpecialMember(CD);
10373      if (!CD->isInvalidDecl())
10374        DefineImplicitDefaultConstructor(DefaultLoc, CD);
10375      break;
10376    }
10377
10378    case CXXCopyConstructor: {
10379      CXXConstructorDecl *CD = cast<CXXConstructorDecl>(MD);
10380      CheckExplicitlyDefaultedSpecialMember(CD);
10381      if (!CD->isInvalidDecl())
10382        DefineImplicitCopyConstructor(DefaultLoc, CD);
10383      break;
10384    }
10385
10386    case CXXCopyAssignment: {
10387      CheckExplicitlyDefaultedSpecialMember(MD);
10388      if (!MD->isInvalidDecl())
10389        DefineImplicitCopyAssignment(DefaultLoc, MD);
10390      break;
10391    }
10392
10393    case CXXDestructor: {
10394      CXXDestructorDecl *DD = cast<CXXDestructorDecl>(MD);
10395      CheckExplicitlyDefaultedSpecialMember(DD);
10396      if (!DD->isInvalidDecl())
10397        DefineImplicitDestructor(DefaultLoc, DD);
10398      break;
10399    }
10400
10401    case CXXMoveConstructor: {
10402      CXXConstructorDecl *CD = cast<CXXConstructorDecl>(MD);
10403      CheckExplicitlyDefaultedSpecialMember(CD);
10404      if (!CD->isInvalidDecl())
10405        DefineImplicitMoveConstructor(DefaultLoc, CD);
10406      break;
10407    }
10408
10409    case CXXMoveAssignment: {
10410      CheckExplicitlyDefaultedSpecialMember(MD);
10411      if (!MD->isInvalidDecl())
10412        DefineImplicitMoveAssignment(DefaultLoc, MD);
10413      break;
10414    }
10415
10416    case CXXInvalid:
10417      llvm_unreachable("Invalid special member.");
10418    }
10419  } else {
10420    Diag(DefaultLoc, diag::err_default_special_members);
10421  }
10422}
10423
10424static void SearchForReturnInStmt(Sema &Self, Stmt *S) {
10425  for (Stmt::child_range CI = S->children(); CI; ++CI) {
10426    Stmt *SubStmt = *CI;
10427    if (!SubStmt)
10428      continue;
10429    if (isa<ReturnStmt>(SubStmt))
10430      Self.Diag(SubStmt->getLocStart(),
10431           diag::err_return_in_constructor_handler);
10432    if (!isa<Expr>(SubStmt))
10433      SearchForReturnInStmt(Self, SubStmt);
10434  }
10435}
10436
10437void Sema::DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock) {
10438  for (unsigned I = 0, E = TryBlock->getNumHandlers(); I != E; ++I) {
10439    CXXCatchStmt *Handler = TryBlock->getHandler(I);
10440    SearchForReturnInStmt(*this, Handler);
10441  }
10442}
10443
10444bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
10445                                             const CXXMethodDecl *Old) {
10446  QualType NewTy = New->getType()->getAs<FunctionType>()->getResultType();
10447  QualType OldTy = Old->getType()->getAs<FunctionType>()->getResultType();
10448
10449  if (Context.hasSameType(NewTy, OldTy) ||
10450      NewTy->isDependentType() || OldTy->isDependentType())
10451    return false;
10452
10453  // Check if the return types are covariant
10454  QualType NewClassTy, OldClassTy;
10455
10456  /// Both types must be pointers or references to classes.
10457  if (const PointerType *NewPT = NewTy->getAs<PointerType>()) {
10458    if (const PointerType *OldPT = OldTy->getAs<PointerType>()) {
10459      NewClassTy = NewPT->getPointeeType();
10460      OldClassTy = OldPT->getPointeeType();
10461    }
10462  } else if (const ReferenceType *NewRT = NewTy->getAs<ReferenceType>()) {
10463    if (const ReferenceType *OldRT = OldTy->getAs<ReferenceType>()) {
10464      if (NewRT->getTypeClass() == OldRT->getTypeClass()) {
10465        NewClassTy = NewRT->getPointeeType();
10466        OldClassTy = OldRT->getPointeeType();
10467      }
10468    }
10469  }
10470
10471  // The return types aren't either both pointers or references to a class type.
10472  if (NewClassTy.isNull()) {
10473    Diag(New->getLocation(),
10474         diag::err_different_return_type_for_overriding_virtual_function)
10475      << New->getDeclName() << NewTy << OldTy;
10476    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10477
10478    return true;
10479  }
10480
10481  // C++ [class.virtual]p6:
10482  //   If the return type of D::f differs from the return type of B::f, the
10483  //   class type in the return type of D::f shall be complete at the point of
10484  //   declaration of D::f or shall be the class type D.
10485  if (const RecordType *RT = NewClassTy->getAs<RecordType>()) {
10486    if (!RT->isBeingDefined() &&
10487        RequireCompleteType(New->getLocation(), NewClassTy,
10488                            diag::err_covariant_return_incomplete,
10489                            New->getDeclName()))
10490    return true;
10491  }
10492
10493  if (!Context.hasSameUnqualifiedType(NewClassTy, OldClassTy)) {
10494    // Check if the new class derives from the old class.
10495    if (!IsDerivedFrom(NewClassTy, OldClassTy)) {
10496      Diag(New->getLocation(),
10497           diag::err_covariant_return_not_derived)
10498      << New->getDeclName() << NewTy << OldTy;
10499      Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10500      return true;
10501    }
10502
10503    // Check if we the conversion from derived to base is valid.
10504    if (CheckDerivedToBaseConversion(NewClassTy, OldClassTy,
10505                    diag::err_covariant_return_inaccessible_base,
10506                    diag::err_covariant_return_ambiguous_derived_to_base_conv,
10507                    // FIXME: Should this point to the return type?
10508                    New->getLocation(), SourceRange(), New->getDeclName(), 0)) {
10509      // FIXME: this note won't trigger for delayed access control
10510      // diagnostics, and it's impossible to get an undelayed error
10511      // here from access control during the original parse because
10512      // the ParsingDeclSpec/ParsingDeclarator are still in scope.
10513      Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10514      return true;
10515    }
10516  }
10517
10518  // The qualifiers of the return types must be the same.
10519  if (NewTy.getLocalCVRQualifiers() != OldTy.getLocalCVRQualifiers()) {
10520    Diag(New->getLocation(),
10521         diag::err_covariant_return_type_different_qualifications)
10522    << New->getDeclName() << NewTy << OldTy;
10523    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10524    return true;
10525  };
10526
10527
10528  // The new class type must have the same or less qualifiers as the old type.
10529  if (NewClassTy.isMoreQualifiedThan(OldClassTy)) {
10530    Diag(New->getLocation(),
10531         diag::err_covariant_return_type_class_type_more_qualified)
10532    << New->getDeclName() << NewTy << OldTy;
10533    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10534    return true;
10535  };
10536
10537  return false;
10538}
10539
10540/// \brief Mark the given method pure.
10541///
10542/// \param Method the method to be marked pure.
10543///
10544/// \param InitRange the source range that covers the "0" initializer.
10545bool Sema::CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange) {
10546  SourceLocation EndLoc = InitRange.getEnd();
10547  if (EndLoc.isValid())
10548    Method->setRangeEnd(EndLoc);
10549
10550  if (Method->isVirtual() || Method->getParent()->isDependentContext()) {
10551    Method->setPure();
10552    return false;
10553  }
10554
10555  if (!Method->isInvalidDecl())
10556    Diag(Method->getLocation(), diag::err_non_virtual_pure)
10557      << Method->getDeclName() << InitRange;
10558  return true;
10559}
10560
10561/// \brief Determine whether the given declaration is a static data member.
10562static bool isStaticDataMember(Decl *D) {
10563  VarDecl *Var = dyn_cast_or_null<VarDecl>(D);
10564  if (!Var)
10565    return false;
10566
10567  return Var->isStaticDataMember();
10568}
10569/// ActOnCXXEnterDeclInitializer - Invoked when we are about to parse
10570/// an initializer for the out-of-line declaration 'Dcl'.  The scope
10571/// is a fresh scope pushed for just this purpose.
10572///
10573/// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
10574/// static data member of class X, names should be looked up in the scope of
10575/// class X.
10576void Sema::ActOnCXXEnterDeclInitializer(Scope *S, Decl *D) {
10577  // If there is no declaration, there was an error parsing it.
10578  if (D == 0 || D->isInvalidDecl()) return;
10579
10580  // We should only get called for declarations with scope specifiers, like:
10581  //   int foo::bar;
10582  assert(D->isOutOfLine());
10583  EnterDeclaratorContext(S, D->getDeclContext());
10584
10585  // If we are parsing the initializer for a static data member, push a
10586  // new expression evaluation context that is associated with this static
10587  // data member.
10588  if (isStaticDataMember(D))
10589    PushExpressionEvaluationContext(PotentiallyEvaluated, D);
10590}
10591
10592/// ActOnCXXExitDeclInitializer - Invoked after we are finished parsing an
10593/// initializer for the out-of-line declaration 'D'.
10594void Sema::ActOnCXXExitDeclInitializer(Scope *S, Decl *D) {
10595  // If there is no declaration, there was an error parsing it.
10596  if (D == 0 || D->isInvalidDecl()) return;
10597
10598  if (isStaticDataMember(D))
10599    PopExpressionEvaluationContext();
10600
10601  assert(D->isOutOfLine());
10602  ExitDeclaratorContext(S);
10603}
10604
10605/// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a
10606/// C++ if/switch/while/for statement.
10607/// e.g: "if (int x = f()) {...}"
10608DeclResult Sema::ActOnCXXConditionDeclaration(Scope *S, Declarator &D) {
10609  // C++ 6.4p2:
10610  // The declarator shall not specify a function or an array.
10611  // The type-specifier-seq shall not contain typedef and shall not declare a
10612  // new class or enumeration.
10613  assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
10614         "Parser allowed 'typedef' as storage class of condition decl.");
10615
10616  Decl *Dcl = ActOnDeclarator(S, D);
10617  if (!Dcl)
10618    return true;
10619
10620  if (isa<FunctionDecl>(Dcl)) { // The declarator shall not specify a function.
10621    Diag(Dcl->getLocation(), diag::err_invalid_use_of_function_type)
10622      << D.getSourceRange();
10623    return true;
10624  }
10625
10626  return Dcl;
10627}
10628
10629void Sema::LoadExternalVTableUses() {
10630  if (!ExternalSource)
10631    return;
10632
10633  SmallVector<ExternalVTableUse, 4> VTables;
10634  ExternalSource->ReadUsedVTables(VTables);
10635  SmallVector<VTableUse, 4> NewUses;
10636  for (unsigned I = 0, N = VTables.size(); I != N; ++I) {
10637    llvm::DenseMap<CXXRecordDecl *, bool>::iterator Pos
10638      = VTablesUsed.find(VTables[I].Record);
10639    // Even if a definition wasn't required before, it may be required now.
10640    if (Pos != VTablesUsed.end()) {
10641      if (!Pos->second && VTables[I].DefinitionRequired)
10642        Pos->second = true;
10643      continue;
10644    }
10645
10646    VTablesUsed[VTables[I].Record] = VTables[I].DefinitionRequired;
10647    NewUses.push_back(VTableUse(VTables[I].Record, VTables[I].Location));
10648  }
10649
10650  VTableUses.insert(VTableUses.begin(), NewUses.begin(), NewUses.end());
10651}
10652
10653void Sema::MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class,
10654                          bool DefinitionRequired) {
10655  // Ignore any vtable uses in unevaluated operands or for classes that do
10656  // not have a vtable.
10657  if (!Class->isDynamicClass() || Class->isDependentContext() ||
10658      CurContext->isDependentContext() ||
10659      ExprEvalContexts.back().Context == Unevaluated)
10660    return;
10661
10662  // Try to insert this class into the map.
10663  LoadExternalVTableUses();
10664  Class = cast<CXXRecordDecl>(Class->getCanonicalDecl());
10665  std::pair<llvm::DenseMap<CXXRecordDecl *, bool>::iterator, bool>
10666    Pos = VTablesUsed.insert(std::make_pair(Class, DefinitionRequired));
10667  if (!Pos.second) {
10668    // If we already had an entry, check to see if we are promoting this vtable
10669    // to required a definition. If so, we need to reappend to the VTableUses
10670    // list, since we may have already processed the first entry.
10671    if (DefinitionRequired && !Pos.first->second) {
10672      Pos.first->second = true;
10673    } else {
10674      // Otherwise, we can early exit.
10675      return;
10676    }
10677  }
10678
10679  // Local classes need to have their virtual members marked
10680  // immediately. For all other classes, we mark their virtual members
10681  // at the end of the translation unit.
10682  if (Class->isLocalClass())
10683    MarkVirtualMembersReferenced(Loc, Class);
10684  else
10685    VTableUses.push_back(std::make_pair(Class, Loc));
10686}
10687
10688bool Sema::DefineUsedVTables() {
10689  LoadExternalVTableUses();
10690  if (VTableUses.empty())
10691    return false;
10692
10693  // Note: The VTableUses vector could grow as a result of marking
10694  // the members of a class as "used", so we check the size each
10695  // time through the loop and prefer indices (with are stable) to
10696  // iterators (which are not).
10697  bool DefinedAnything = false;
10698  for (unsigned I = 0; I != VTableUses.size(); ++I) {
10699    CXXRecordDecl *Class = VTableUses[I].first->getDefinition();
10700    if (!Class)
10701      continue;
10702
10703    SourceLocation Loc = VTableUses[I].second;
10704
10705    // If this class has a key function, but that key function is
10706    // defined in another translation unit, we don't need to emit the
10707    // vtable even though we're using it.
10708    const CXXMethodDecl *KeyFunction = Context.getKeyFunction(Class);
10709    if (KeyFunction && !KeyFunction->hasBody()) {
10710      switch (KeyFunction->getTemplateSpecializationKind()) {
10711      case TSK_Undeclared:
10712      case TSK_ExplicitSpecialization:
10713      case TSK_ExplicitInstantiationDeclaration:
10714        // The key function is in another translation unit.
10715        continue;
10716
10717      case TSK_ExplicitInstantiationDefinition:
10718      case TSK_ImplicitInstantiation:
10719        // We will be instantiating the key function.
10720        break;
10721      }
10722    } else if (!KeyFunction) {
10723      // If we have a class with no key function that is the subject
10724      // of an explicit instantiation declaration, suppress the
10725      // vtable; it will live with the explicit instantiation
10726      // definition.
10727      bool IsExplicitInstantiationDeclaration
10728        = Class->getTemplateSpecializationKind()
10729                                      == TSK_ExplicitInstantiationDeclaration;
10730      for (TagDecl::redecl_iterator R = Class->redecls_begin(),
10731                                 REnd = Class->redecls_end();
10732           R != REnd; ++R) {
10733        TemplateSpecializationKind TSK
10734          = cast<CXXRecordDecl>(*R)->getTemplateSpecializationKind();
10735        if (TSK == TSK_ExplicitInstantiationDeclaration)
10736          IsExplicitInstantiationDeclaration = true;
10737        else if (TSK == TSK_ExplicitInstantiationDefinition) {
10738          IsExplicitInstantiationDeclaration = false;
10739          break;
10740        }
10741      }
10742
10743      if (IsExplicitInstantiationDeclaration)
10744        continue;
10745    }
10746
10747    // Mark all of the virtual members of this class as referenced, so
10748    // that we can build a vtable. Then, tell the AST consumer that a
10749    // vtable for this class is required.
10750    DefinedAnything = true;
10751    MarkVirtualMembersReferenced(Loc, Class);
10752    CXXRecordDecl *Canonical = cast<CXXRecordDecl>(Class->getCanonicalDecl());
10753    Consumer.HandleVTable(Class, VTablesUsed[Canonical]);
10754
10755    // Optionally warn if we're emitting a weak vtable.
10756    if (Class->getLinkage() == ExternalLinkage &&
10757        Class->getTemplateSpecializationKind() != TSK_ImplicitInstantiation) {
10758      const FunctionDecl *KeyFunctionDef = 0;
10759      if (!KeyFunction ||
10760          (KeyFunction->hasBody(KeyFunctionDef) &&
10761           KeyFunctionDef->isInlined()))
10762        Diag(Class->getLocation(), Class->getTemplateSpecializationKind() ==
10763             TSK_ExplicitInstantiationDefinition
10764             ? diag::warn_weak_template_vtable : diag::warn_weak_vtable)
10765          << Class;
10766    }
10767  }
10768  VTableUses.clear();
10769
10770  return DefinedAnything;
10771}
10772
10773void Sema::MarkVirtualMembersReferenced(SourceLocation Loc,
10774                                        const CXXRecordDecl *RD) {
10775  for (CXXRecordDecl::method_iterator i = RD->method_begin(),
10776       e = RD->method_end(); i != e; ++i) {
10777    CXXMethodDecl *MD = *i;
10778
10779    // C++ [basic.def.odr]p2:
10780    //   [...] A virtual member function is used if it is not pure. [...]
10781    if (MD->isVirtual() && !MD->isPure())
10782      MarkFunctionReferenced(Loc, MD);
10783  }
10784
10785  // Only classes that have virtual bases need a VTT.
10786  if (RD->getNumVBases() == 0)
10787    return;
10788
10789  for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
10790           e = RD->bases_end(); i != e; ++i) {
10791    const CXXRecordDecl *Base =
10792        cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
10793    if (Base->getNumVBases() == 0)
10794      continue;
10795    MarkVirtualMembersReferenced(Loc, Base);
10796  }
10797}
10798
10799/// SetIvarInitializers - This routine builds initialization ASTs for the
10800/// Objective-C implementation whose ivars need be initialized.
10801void Sema::SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation) {
10802  if (!getLangOpts().CPlusPlus)
10803    return;
10804  if (ObjCInterfaceDecl *OID = ObjCImplementation->getClassInterface()) {
10805    SmallVector<ObjCIvarDecl*, 8> ivars;
10806    CollectIvarsToConstructOrDestruct(OID, ivars);
10807    if (ivars.empty())
10808      return;
10809    SmallVector<CXXCtorInitializer*, 32> AllToInit;
10810    for (unsigned i = 0; i < ivars.size(); i++) {
10811      FieldDecl *Field = ivars[i];
10812      if (Field->isInvalidDecl())
10813        continue;
10814
10815      CXXCtorInitializer *Member;
10816      InitializedEntity InitEntity = InitializedEntity::InitializeMember(Field);
10817      InitializationKind InitKind =
10818        InitializationKind::CreateDefault(ObjCImplementation->getLocation());
10819
10820      InitializationSequence InitSeq(*this, InitEntity, InitKind, 0, 0);
10821      ExprResult MemberInit =
10822        InitSeq.Perform(*this, InitEntity, InitKind, MultiExprArg());
10823      MemberInit = MaybeCreateExprWithCleanups(MemberInit);
10824      // Note, MemberInit could actually come back empty if no initialization
10825      // is required (e.g., because it would call a trivial default constructor)
10826      if (!MemberInit.get() || MemberInit.isInvalid())
10827        continue;
10828
10829      Member =
10830        new (Context) CXXCtorInitializer(Context, Field, SourceLocation(),
10831                                         SourceLocation(),
10832                                         MemberInit.takeAs<Expr>(),
10833                                         SourceLocation());
10834      AllToInit.push_back(Member);
10835
10836      // Be sure that the destructor is accessible and is marked as referenced.
10837      if (const RecordType *RecordTy
10838                  = Context.getBaseElementType(Field->getType())
10839                                                        ->getAs<RecordType>()) {
10840                    CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl());
10841        if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
10842          MarkFunctionReferenced(Field->getLocation(), Destructor);
10843          CheckDestructorAccess(Field->getLocation(), Destructor,
10844                            PDiag(diag::err_access_dtor_ivar)
10845                              << Context.getBaseElementType(Field->getType()));
10846        }
10847      }
10848    }
10849    ObjCImplementation->setIvarInitializers(Context,
10850                                            AllToInit.data(), AllToInit.size());
10851  }
10852}
10853
10854static
10855void DelegatingCycleHelper(CXXConstructorDecl* Ctor,
10856                           llvm::SmallSet<CXXConstructorDecl*, 4> &Valid,
10857                           llvm::SmallSet<CXXConstructorDecl*, 4> &Invalid,
10858                           llvm::SmallSet<CXXConstructorDecl*, 4> &Current,
10859                           Sema &S) {
10860  llvm::SmallSet<CXXConstructorDecl*, 4>::iterator CI = Current.begin(),
10861                                                   CE = Current.end();
10862  if (Ctor->isInvalidDecl())
10863    return;
10864
10865  const FunctionDecl *FNTarget = 0;
10866  CXXConstructorDecl *Target;
10867
10868  // We ignore the result here since if we don't have a body, Target will be
10869  // null below.
10870  (void)Ctor->getTargetConstructor()->hasBody(FNTarget);
10871  Target
10872= const_cast<CXXConstructorDecl*>(cast_or_null<CXXConstructorDecl>(FNTarget));
10873
10874  CXXConstructorDecl *Canonical = Ctor->getCanonicalDecl(),
10875                     // Avoid dereferencing a null pointer here.
10876                     *TCanonical = Target ? Target->getCanonicalDecl() : 0;
10877
10878  if (!Current.insert(Canonical))
10879    return;
10880
10881  // We know that beyond here, we aren't chaining into a cycle.
10882  if (!Target || !Target->isDelegatingConstructor() ||
10883      Target->isInvalidDecl() || Valid.count(TCanonical)) {
10884    for (CI = Current.begin(), CE = Current.end(); CI != CE; ++CI)
10885      Valid.insert(*CI);
10886    Current.clear();
10887  // We've hit a cycle.
10888  } else if (TCanonical == Canonical || Invalid.count(TCanonical) ||
10889             Current.count(TCanonical)) {
10890    // If we haven't diagnosed this cycle yet, do so now.
10891    if (!Invalid.count(TCanonical)) {
10892      S.Diag((*Ctor->init_begin())->getSourceLocation(),
10893             diag::warn_delegating_ctor_cycle)
10894        << Ctor;
10895
10896      // Don't add a note for a function delegating directo to itself.
10897      if (TCanonical != Canonical)
10898        S.Diag(Target->getLocation(), diag::note_it_delegates_to);
10899
10900      CXXConstructorDecl *C = Target;
10901      while (C->getCanonicalDecl() != Canonical) {
10902        (void)C->getTargetConstructor()->hasBody(FNTarget);
10903        assert(FNTarget && "Ctor cycle through bodiless function");
10904
10905        C
10906       = const_cast<CXXConstructorDecl*>(cast<CXXConstructorDecl>(FNTarget));
10907        S.Diag(C->getLocation(), diag::note_which_delegates_to);
10908      }
10909    }
10910
10911    for (CI = Current.begin(), CE = Current.end(); CI != CE; ++CI)
10912      Invalid.insert(*CI);
10913    Current.clear();
10914  } else {
10915    DelegatingCycleHelper(Target, Valid, Invalid, Current, S);
10916  }
10917}
10918
10919
10920void Sema::CheckDelegatingCtorCycles() {
10921  llvm::SmallSet<CXXConstructorDecl*, 4> Valid, Invalid, Current;
10922
10923  llvm::SmallSet<CXXConstructorDecl*, 4>::iterator CI = Current.begin(),
10924                                                   CE = Current.end();
10925
10926  for (DelegatingCtorDeclsType::iterator
10927         I = DelegatingCtorDecls.begin(ExternalSource),
10928         E = DelegatingCtorDecls.end();
10929       I != E; ++I) {
10930   DelegatingCycleHelper(*I, Valid, Invalid, Current, *this);
10931  }
10932
10933  for (CI = Invalid.begin(), CE = Invalid.end(); CI != CE; ++CI)
10934    (*CI)->setInvalidDecl();
10935}
10936
10937namespace {
10938  /// \brief AST visitor that finds references to the 'this' expression.
10939  class FindCXXThisExpr : public RecursiveASTVisitor<FindCXXThisExpr> {
10940    Sema &S;
10941
10942  public:
10943    explicit FindCXXThisExpr(Sema &S) : S(S) { }
10944
10945    bool VisitCXXThisExpr(CXXThisExpr *E) {
10946      S.Diag(E->getLocation(), diag::err_this_static_member_func)
10947        << E->isImplicit();
10948      return false;
10949    }
10950  };
10951}
10952
10953bool Sema::checkThisInStaticMemberFunctionType(CXXMethodDecl *Method) {
10954  TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
10955  if (!TSInfo)
10956    return false;
10957
10958  TypeLoc TL = TSInfo->getTypeLoc();
10959  FunctionProtoTypeLoc *ProtoTL = dyn_cast<FunctionProtoTypeLoc>(&TL);
10960  if (!ProtoTL)
10961    return false;
10962
10963  // C++11 [expr.prim.general]p3:
10964  //   [The expression this] shall not appear before the optional
10965  //   cv-qualifier-seq and it shall not appear within the declaration of a
10966  //   static member function (although its type and value category are defined
10967  //   within a static member function as they are within a non-static member
10968  //   function). [ Note: this is because declaration matching does not occur
10969  //  until the complete declarator is known. - end note ]
10970  const FunctionProtoType *Proto = ProtoTL->getTypePtr();
10971  FindCXXThisExpr Finder(*this);
10972
10973  // If the return type came after the cv-qualifier-seq, check it now.
10974  if (Proto->hasTrailingReturn() &&
10975      !Finder.TraverseTypeLoc(ProtoTL->getResultLoc()))
10976    return true;
10977
10978  // Check the exception specification.
10979  if (checkThisInStaticMemberFunctionExceptionSpec(Method))
10980    return true;
10981
10982  return checkThisInStaticMemberFunctionAttributes(Method);
10983}
10984
10985bool Sema::checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl *Method) {
10986  TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
10987  if (!TSInfo)
10988    return false;
10989
10990  TypeLoc TL = TSInfo->getTypeLoc();
10991  FunctionProtoTypeLoc *ProtoTL = dyn_cast<FunctionProtoTypeLoc>(&TL);
10992  if (!ProtoTL)
10993    return false;
10994
10995  const FunctionProtoType *Proto = ProtoTL->getTypePtr();
10996  FindCXXThisExpr Finder(*this);
10997
10998  switch (Proto->getExceptionSpecType()) {
10999  case EST_Uninstantiated:
11000  case EST_BasicNoexcept:
11001  case EST_Delayed:
11002  case EST_DynamicNone:
11003  case EST_MSAny:
11004  case EST_None:
11005    break;
11006
11007  case EST_ComputedNoexcept:
11008    if (!Finder.TraverseStmt(Proto->getNoexceptExpr()))
11009      return true;
11010
11011  case EST_Dynamic:
11012    for (FunctionProtoType::exception_iterator E = Proto->exception_begin(),
11013         EEnd = Proto->exception_end();
11014         E != EEnd; ++E) {
11015      if (!Finder.TraverseType(*E))
11016        return true;
11017    }
11018    break;
11019  }
11020
11021  return false;
11022}
11023
11024bool Sema::checkThisInStaticMemberFunctionAttributes(CXXMethodDecl *Method) {
11025  FindCXXThisExpr Finder(*this);
11026
11027  // Check attributes.
11028  for (Decl::attr_iterator A = Method->attr_begin(), AEnd = Method->attr_end();
11029       A != AEnd; ++A) {
11030    // FIXME: This should be emitted by tblgen.
11031    Expr *Arg = 0;
11032    ArrayRef<Expr *> Args;
11033    if (GuardedByAttr *G = dyn_cast<GuardedByAttr>(*A))
11034      Arg = G->getArg();
11035    else if (PtGuardedByAttr *G = dyn_cast<PtGuardedByAttr>(*A))
11036      Arg = G->getArg();
11037    else if (AcquiredAfterAttr *AA = dyn_cast<AcquiredAfterAttr>(*A))
11038      Args = ArrayRef<Expr *>(AA->args_begin(), AA->args_size());
11039    else if (AcquiredBeforeAttr *AB = dyn_cast<AcquiredBeforeAttr>(*A))
11040      Args = ArrayRef<Expr *>(AB->args_begin(), AB->args_size());
11041    else if (ExclusiveLockFunctionAttr *ELF
11042               = dyn_cast<ExclusiveLockFunctionAttr>(*A))
11043      Args = ArrayRef<Expr *>(ELF->args_begin(), ELF->args_size());
11044    else if (SharedLockFunctionAttr *SLF
11045               = dyn_cast<SharedLockFunctionAttr>(*A))
11046      Args = ArrayRef<Expr *>(SLF->args_begin(), SLF->args_size());
11047    else if (ExclusiveTrylockFunctionAttr *ETLF
11048               = dyn_cast<ExclusiveTrylockFunctionAttr>(*A)) {
11049      Arg = ETLF->getSuccessValue();
11050      Args = ArrayRef<Expr *>(ETLF->args_begin(), ETLF->args_size());
11051    } else if (SharedTrylockFunctionAttr *STLF
11052                 = dyn_cast<SharedTrylockFunctionAttr>(*A)) {
11053      Arg = STLF->getSuccessValue();
11054      Args = ArrayRef<Expr *>(STLF->args_begin(), STLF->args_size());
11055    } else if (UnlockFunctionAttr *UF = dyn_cast<UnlockFunctionAttr>(*A))
11056      Args = ArrayRef<Expr *>(UF->args_begin(), UF->args_size());
11057    else if (LockReturnedAttr *LR = dyn_cast<LockReturnedAttr>(*A))
11058      Arg = LR->getArg();
11059    else if (LocksExcludedAttr *LE = dyn_cast<LocksExcludedAttr>(*A))
11060      Args = ArrayRef<Expr *>(LE->args_begin(), LE->args_size());
11061    else if (ExclusiveLocksRequiredAttr *ELR
11062               = dyn_cast<ExclusiveLocksRequiredAttr>(*A))
11063      Args = ArrayRef<Expr *>(ELR->args_begin(), ELR->args_size());
11064    else if (SharedLocksRequiredAttr *SLR
11065               = dyn_cast<SharedLocksRequiredAttr>(*A))
11066      Args = ArrayRef<Expr *>(SLR->args_begin(), SLR->args_size());
11067
11068    if (Arg && !Finder.TraverseStmt(Arg))
11069      return true;
11070
11071    for (unsigned I = 0, N = Args.size(); I != N; ++I) {
11072      if (!Finder.TraverseStmt(Args[I]))
11073        return true;
11074    }
11075  }
11076
11077  return false;
11078}
11079
11080void
11081Sema::checkExceptionSpecification(ExceptionSpecificationType EST,
11082                                  ArrayRef<ParsedType> DynamicExceptions,
11083                                  ArrayRef<SourceRange> DynamicExceptionRanges,
11084                                  Expr *NoexceptExpr,
11085                                  llvm::SmallVectorImpl<QualType> &Exceptions,
11086                                  FunctionProtoType::ExtProtoInfo &EPI) {
11087  Exceptions.clear();
11088  EPI.ExceptionSpecType = EST;
11089  if (EST == EST_Dynamic) {
11090    Exceptions.reserve(DynamicExceptions.size());
11091    for (unsigned ei = 0, ee = DynamicExceptions.size(); ei != ee; ++ei) {
11092      // FIXME: Preserve type source info.
11093      QualType ET = GetTypeFromParser(DynamicExceptions[ei]);
11094
11095      SmallVector<UnexpandedParameterPack, 2> Unexpanded;
11096      collectUnexpandedParameterPacks(ET, Unexpanded);
11097      if (!Unexpanded.empty()) {
11098        DiagnoseUnexpandedParameterPacks(DynamicExceptionRanges[ei].getBegin(),
11099                                         UPPC_ExceptionType,
11100                                         Unexpanded);
11101        continue;
11102      }
11103
11104      // Check that the type is valid for an exception spec, and
11105      // drop it if not.
11106      if (!CheckSpecifiedExceptionType(ET, DynamicExceptionRanges[ei]))
11107        Exceptions.push_back(ET);
11108    }
11109    EPI.NumExceptions = Exceptions.size();
11110    EPI.Exceptions = Exceptions.data();
11111    return;
11112  }
11113
11114  if (EST == EST_ComputedNoexcept) {
11115    // If an error occurred, there's no expression here.
11116    if (NoexceptExpr) {
11117      assert((NoexceptExpr->isTypeDependent() ||
11118              NoexceptExpr->getType()->getCanonicalTypeUnqualified() ==
11119              Context.BoolTy) &&
11120             "Parser should have made sure that the expression is boolean");
11121      if (NoexceptExpr && DiagnoseUnexpandedParameterPack(NoexceptExpr)) {
11122        EPI.ExceptionSpecType = EST_BasicNoexcept;
11123        return;
11124      }
11125
11126      if (!NoexceptExpr->isValueDependent())
11127        NoexceptExpr = VerifyIntegerConstantExpression(NoexceptExpr, 0,
11128                         diag::err_noexcept_needs_constant_expression,
11129                         /*AllowFold*/ false).take();
11130      EPI.NoexceptExpr = NoexceptExpr;
11131    }
11132    return;
11133  }
11134}
11135
11136/// IdentifyCUDATarget - Determine the CUDA compilation target for this function
11137Sema::CUDAFunctionTarget Sema::IdentifyCUDATarget(const FunctionDecl *D) {
11138  // Implicitly declared functions (e.g. copy constructors) are
11139  // __host__ __device__
11140  if (D->isImplicit())
11141    return CFT_HostDevice;
11142
11143  if (D->hasAttr<CUDAGlobalAttr>())
11144    return CFT_Global;
11145
11146  if (D->hasAttr<CUDADeviceAttr>()) {
11147    if (D->hasAttr<CUDAHostAttr>())
11148      return CFT_HostDevice;
11149    else
11150      return CFT_Device;
11151  }
11152
11153  return CFT_Host;
11154}
11155
11156bool Sema::CheckCUDATarget(CUDAFunctionTarget CallerTarget,
11157                           CUDAFunctionTarget CalleeTarget) {
11158  // CUDA B.1.1 "The __device__ qualifier declares a function that is...
11159  // Callable from the device only."
11160  if (CallerTarget == CFT_Host && CalleeTarget == CFT_Device)
11161    return true;
11162
11163  // CUDA B.1.2 "The __global__ qualifier declares a function that is...
11164  // Callable from the host only."
11165  // CUDA B.1.3 "The __host__ qualifier declares a function that is...
11166  // Callable from the host only."
11167  if ((CallerTarget == CFT_Device || CallerTarget == CFT_Global) &&
11168      (CalleeTarget == CFT_Host || CalleeTarget == CFT_Global))
11169    return true;
11170
11171  if (CallerTarget == CFT_HostDevice && CalleeTarget != CFT_HostDevice)
11172    return true;
11173
11174  return false;
11175}
11176