SemaDeclCXX.cpp revision 16006c901315fa12a108b4e571f187f4b676e426
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 "Sema.h"
15#include "SemaInit.h"
16#include "Lookup.h"
17#include "clang/AST/ASTConsumer.h"
18#include "clang/AST/ASTContext.h"
19#include "clang/AST/RecordLayout.h"
20#include "clang/AST/CXXInheritance.h"
21#include "clang/AST/DeclVisitor.h"
22#include "clang/AST/TypeLoc.h"
23#include "clang/AST/TypeOrdering.h"
24#include "clang/AST/StmtVisitor.h"
25#include "clang/Parse/DeclSpec.h"
26#include "clang/Parse/Template.h"
27#include "clang/Basic/PartialDiagnostic.h"
28#include "clang/Lex/Preprocessor.h"
29#include "llvm/ADT/STLExtras.h"
30#include <map>
31#include <set>
32
33using namespace clang;
34
35//===----------------------------------------------------------------------===//
36// CheckDefaultArgumentVisitor
37//===----------------------------------------------------------------------===//
38
39namespace {
40  /// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
41  /// the default argument of a parameter to determine whether it
42  /// contains any ill-formed subexpressions. For example, this will
43  /// diagnose the use of local variables or parameters within the
44  /// default argument expression.
45  class CheckDefaultArgumentVisitor
46    : public StmtVisitor<CheckDefaultArgumentVisitor, bool> {
47    Expr *DefaultArg;
48    Sema *S;
49
50  public:
51    CheckDefaultArgumentVisitor(Expr *defarg, Sema *s)
52      : DefaultArg(defarg), S(s) {}
53
54    bool VisitExpr(Expr *Node);
55    bool VisitDeclRefExpr(DeclRefExpr *DRE);
56    bool VisitCXXThisExpr(CXXThisExpr *ThisE);
57  };
58
59  /// VisitExpr - Visit all of the children of this expression.
60  bool CheckDefaultArgumentVisitor::VisitExpr(Expr *Node) {
61    bool IsInvalid = false;
62    for (Stmt::child_iterator I = Node->child_begin(),
63         E = Node->child_end(); I != E; ++I)
64      IsInvalid |= Visit(*I);
65    return IsInvalid;
66  }
67
68  /// VisitDeclRefExpr - Visit a reference to a declaration, to
69  /// determine whether this declaration can be used in the default
70  /// argument expression.
71  bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(DeclRefExpr *DRE) {
72    NamedDecl *Decl = DRE->getDecl();
73    if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Decl)) {
74      // C++ [dcl.fct.default]p9
75      //   Default arguments are evaluated each time the function is
76      //   called. The order of evaluation of function arguments is
77      //   unspecified. Consequently, parameters of a function shall not
78      //   be used in default argument expressions, even if they are not
79      //   evaluated. Parameters of a function declared before a default
80      //   argument expression are in scope and can hide namespace and
81      //   class member names.
82      return S->Diag(DRE->getSourceRange().getBegin(),
83                     diag::err_param_default_argument_references_param)
84         << Param->getDeclName() << DefaultArg->getSourceRange();
85    } else if (VarDecl *VDecl = dyn_cast<VarDecl>(Decl)) {
86      // C++ [dcl.fct.default]p7
87      //   Local variables shall not be used in default argument
88      //   expressions.
89      if (VDecl->isBlockVarDecl())
90        return S->Diag(DRE->getSourceRange().getBegin(),
91                       diag::err_param_default_argument_references_local)
92          << VDecl->getDeclName() << DefaultArg->getSourceRange();
93    }
94
95    return false;
96  }
97
98  /// VisitCXXThisExpr - Visit a C++ "this" expression.
99  bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(CXXThisExpr *ThisE) {
100    // C++ [dcl.fct.default]p8:
101    //   The keyword this shall not be used in a default argument of a
102    //   member function.
103    return S->Diag(ThisE->getSourceRange().getBegin(),
104                   diag::err_param_default_argument_references_this)
105               << ThisE->getSourceRange();
106  }
107}
108
109bool
110Sema::SetParamDefaultArgument(ParmVarDecl *Param, ExprArg DefaultArg,
111                              SourceLocation EqualLoc) {
112  QualType ParamType = Param->getType();
113
114  if (RequireCompleteType(Param->getLocation(), Param->getType(),
115                          diag::err_typecheck_decl_incomplete_type)) {
116    Param->setInvalidDecl();
117    return true;
118  }
119
120  Expr *Arg = (Expr *)DefaultArg.get();
121
122  // C++ [dcl.fct.default]p5
123  //   A default argument expression is implicitly converted (clause
124  //   4) to the parameter type. The default argument expression has
125  //   the same semantic constraints as the initializer expression in
126  //   a declaration of a variable of the parameter type, using the
127  //   copy-initialization semantics (8.5).
128  InitializedEntity Entity = InitializedEntity::InitializeParameter(Param);
129  InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(),
130                                                           EqualLoc);
131  if (CheckInitializerTypes(Arg, ParamType, Entity, Kind))
132    return true;
133
134  Arg = MaybeCreateCXXExprWithTemporaries(Arg);
135
136  // Okay: add the default argument to the parameter
137  Param->setDefaultArg(Arg);
138
139  DefaultArg.release();
140
141  return false;
142}
143
144/// ActOnParamDefaultArgument - Check whether the default argument
145/// provided for a function parameter is well-formed. If so, attach it
146/// to the parameter declaration.
147void
148Sema::ActOnParamDefaultArgument(DeclPtrTy param, SourceLocation EqualLoc,
149                                ExprArg defarg) {
150  if (!param || !defarg.get())
151    return;
152
153  ParmVarDecl *Param = cast<ParmVarDecl>(param.getAs<Decl>());
154  UnparsedDefaultArgLocs.erase(Param);
155
156  ExprOwningPtr<Expr> DefaultArg(this, defarg.takeAs<Expr>());
157  QualType ParamType = Param->getType();
158
159  // Default arguments are only permitted in C++
160  if (!getLangOptions().CPlusPlus) {
161    Diag(EqualLoc, diag::err_param_default_argument)
162      << DefaultArg->getSourceRange();
163    Param->setInvalidDecl();
164    return;
165  }
166
167  // Check that the default argument is well-formed
168  CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg.get(), this);
169  if (DefaultArgChecker.Visit(DefaultArg.get())) {
170    Param->setInvalidDecl();
171    return;
172  }
173
174  SetParamDefaultArgument(Param, move(DefaultArg), EqualLoc);
175}
176
177/// ActOnParamUnparsedDefaultArgument - We've seen a default
178/// argument for a function parameter, but we can't parse it yet
179/// because we're inside a class definition. Note that this default
180/// argument will be parsed later.
181void Sema::ActOnParamUnparsedDefaultArgument(DeclPtrTy param,
182                                             SourceLocation EqualLoc,
183                                             SourceLocation ArgLoc) {
184  if (!param)
185    return;
186
187  ParmVarDecl *Param = cast<ParmVarDecl>(param.getAs<Decl>());
188  if (Param)
189    Param->setUnparsedDefaultArg();
190
191  UnparsedDefaultArgLocs[Param] = ArgLoc;
192}
193
194/// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
195/// the default argument for the parameter param failed.
196void Sema::ActOnParamDefaultArgumentError(DeclPtrTy param) {
197  if (!param)
198    return;
199
200  ParmVarDecl *Param = cast<ParmVarDecl>(param.getAs<Decl>());
201
202  Param->setInvalidDecl();
203
204  UnparsedDefaultArgLocs.erase(Param);
205}
206
207/// CheckExtraCXXDefaultArguments - Check for any extra default
208/// arguments in the declarator, which is not a function declaration
209/// or definition and therefore is not permitted to have default
210/// arguments. This routine should be invoked for every declarator
211/// that is not a function declaration or definition.
212void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
213  // C++ [dcl.fct.default]p3
214  //   A default argument expression shall be specified only in the
215  //   parameter-declaration-clause of a function declaration or in a
216  //   template-parameter (14.1). It shall not be specified for a
217  //   parameter pack. If it is specified in a
218  //   parameter-declaration-clause, it shall not occur within a
219  //   declarator or abstract-declarator of a parameter-declaration.
220  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
221    DeclaratorChunk &chunk = D.getTypeObject(i);
222    if (chunk.Kind == DeclaratorChunk::Function) {
223      for (unsigned argIdx = 0, e = chunk.Fun.NumArgs; argIdx != e; ++argIdx) {
224        ParmVarDecl *Param =
225          cast<ParmVarDecl>(chunk.Fun.ArgInfo[argIdx].Param.getAs<Decl>());
226        if (Param->hasUnparsedDefaultArg()) {
227          CachedTokens *Toks = chunk.Fun.ArgInfo[argIdx].DefaultArgTokens;
228          Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
229            << SourceRange((*Toks)[1].getLocation(), Toks->back().getLocation());
230          delete Toks;
231          chunk.Fun.ArgInfo[argIdx].DefaultArgTokens = 0;
232        } else if (Param->getDefaultArg()) {
233          Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
234            << Param->getDefaultArg()->getSourceRange();
235          Param->setDefaultArg(0);
236        }
237      }
238    }
239  }
240}
241
242// MergeCXXFunctionDecl - Merge two declarations of the same C++
243// function, once we already know that they have the same
244// type. Subroutine of MergeFunctionDecl. Returns true if there was an
245// error, false otherwise.
246bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old) {
247  bool Invalid = false;
248
249  // C++ [dcl.fct.default]p4:
250  //   For non-template functions, default arguments can be added in
251  //   later declarations of a function in the same
252  //   scope. Declarations in different scopes have completely
253  //   distinct sets of default arguments. That is, declarations in
254  //   inner scopes do not acquire default arguments from
255  //   declarations in outer scopes, and vice versa. In a given
256  //   function declaration, all parameters subsequent to a
257  //   parameter with a default argument shall have default
258  //   arguments supplied in this or previous declarations. A
259  //   default argument shall not be redefined by a later
260  //   declaration (not even to the same value).
261  //
262  // C++ [dcl.fct.default]p6:
263  //   Except for member functions of class templates, the default arguments
264  //   in a member function definition that appears outside of the class
265  //   definition are added to the set of default arguments provided by the
266  //   member function declaration in the class definition.
267  for (unsigned p = 0, NumParams = Old->getNumParams(); p < NumParams; ++p) {
268    ParmVarDecl *OldParam = Old->getParamDecl(p);
269    ParmVarDecl *NewParam = New->getParamDecl(p);
270
271    if (OldParam->hasDefaultArg() && NewParam->hasDefaultArg()) {
272      // FIXME: If the parameter doesn't have an identifier then the location
273      // points to the '=' which means that the fixit hint won't remove any
274      // extra spaces between the type and the '='.
275      SourceLocation Begin = NewParam->getLocation();
276      if (NewParam->getIdentifier())
277        Begin = PP.getLocForEndOfToken(Begin);
278
279      Diag(NewParam->getLocation(),
280           diag::err_param_default_argument_redefinition)
281        << NewParam->getDefaultArgRange()
282        << CodeModificationHint::CreateRemoval(SourceRange(Begin,
283                                                        NewParam->getLocEnd()));
284
285      // Look for the function declaration where the default argument was
286      // actually written, which may be a declaration prior to Old.
287      for (FunctionDecl *Older = Old->getPreviousDeclaration();
288           Older; Older = Older->getPreviousDeclaration()) {
289        if (!Older->getParamDecl(p)->hasDefaultArg())
290          break;
291
292        OldParam = Older->getParamDecl(p);
293      }
294
295      Diag(OldParam->getLocation(), diag::note_previous_definition)
296        << OldParam->getDefaultArgRange();
297      Invalid = true;
298    } else if (OldParam->hasDefaultArg()) {
299      // Merge the old default argument into the new parameter
300      if (OldParam->hasUninstantiatedDefaultArg())
301        NewParam->setUninstantiatedDefaultArg(
302                                      OldParam->getUninstantiatedDefaultArg());
303      else
304        NewParam->setDefaultArg(OldParam->getDefaultArg());
305    } else if (NewParam->hasDefaultArg()) {
306      if (New->getDescribedFunctionTemplate()) {
307        // Paragraph 4, quoted above, only applies to non-template functions.
308        Diag(NewParam->getLocation(),
309             diag::err_param_default_argument_template_redecl)
310          << NewParam->getDefaultArgRange();
311        Diag(Old->getLocation(), diag::note_template_prev_declaration)
312          << false;
313      } else if (New->getTemplateSpecializationKind()
314                   != TSK_ImplicitInstantiation &&
315                 New->getTemplateSpecializationKind() != TSK_Undeclared) {
316        // C++ [temp.expr.spec]p21:
317        //   Default function arguments shall not be specified in a declaration
318        //   or a definition for one of the following explicit specializations:
319        //     - the explicit specialization of a function template;
320        //     - the explicit specialization of a member function template;
321        //     - the explicit specialization of a member function of a class
322        //       template where the class template specialization to which the
323        //       member function specialization belongs is implicitly
324        //       instantiated.
325        Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
326          << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
327          << New->getDeclName()
328          << NewParam->getDefaultArgRange();
329      } else if (New->getDeclContext()->isDependentContext()) {
330        // C++ [dcl.fct.default]p6 (DR217):
331        //   Default arguments for a member function of a class template shall
332        //   be specified on the initial declaration of the member function
333        //   within the class template.
334        //
335        // Reading the tea leaves a bit in DR217 and its reference to DR205
336        // leads me to the conclusion that one cannot add default function
337        // arguments for an out-of-line definition of a member function of a
338        // dependent type.
339        int WhichKind = 2;
340        if (CXXRecordDecl *Record
341              = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
342          if (Record->getDescribedClassTemplate())
343            WhichKind = 0;
344          else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
345            WhichKind = 1;
346          else
347            WhichKind = 2;
348        }
349
350        Diag(NewParam->getLocation(),
351             diag::err_param_default_argument_member_template_redecl)
352          << WhichKind
353          << NewParam->getDefaultArgRange();
354      }
355    }
356  }
357
358  if (CheckEquivalentExceptionSpec(
359          Old->getType()->getAs<FunctionProtoType>(), Old->getLocation(),
360          New->getType()->getAs<FunctionProtoType>(), New->getLocation()))
361    Invalid = true;
362
363  return Invalid;
364}
365
366/// CheckCXXDefaultArguments - Verify that the default arguments for a
367/// function declaration are well-formed according to C++
368/// [dcl.fct.default].
369void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
370  unsigned NumParams = FD->getNumParams();
371  unsigned p;
372
373  // Find first parameter with a default argument
374  for (p = 0; p < NumParams; ++p) {
375    ParmVarDecl *Param = FD->getParamDecl(p);
376    if (Param->hasDefaultArg())
377      break;
378  }
379
380  // C++ [dcl.fct.default]p4:
381  //   In a given function declaration, all parameters
382  //   subsequent to a parameter with a default argument shall
383  //   have default arguments supplied in this or previous
384  //   declarations. A default argument shall not be redefined
385  //   by a later declaration (not even to the same value).
386  unsigned LastMissingDefaultArg = 0;
387  for (; p < NumParams; ++p) {
388    ParmVarDecl *Param = FD->getParamDecl(p);
389    if (!Param->hasDefaultArg()) {
390      if (Param->isInvalidDecl())
391        /* We already complained about this parameter. */;
392      else if (Param->getIdentifier())
393        Diag(Param->getLocation(),
394             diag::err_param_default_argument_missing_name)
395          << Param->getIdentifier();
396      else
397        Diag(Param->getLocation(),
398             diag::err_param_default_argument_missing);
399
400      LastMissingDefaultArg = p;
401    }
402  }
403
404  if (LastMissingDefaultArg > 0) {
405    // Some default arguments were missing. Clear out all of the
406    // default arguments up to (and including) the last missing
407    // default argument, so that we leave the function parameters
408    // in a semantically valid state.
409    for (p = 0; p <= LastMissingDefaultArg; ++p) {
410      ParmVarDecl *Param = FD->getParamDecl(p);
411      if (Param->hasDefaultArg()) {
412        if (!Param->hasUnparsedDefaultArg())
413          Param->getDefaultArg()->Destroy(Context);
414        Param->setDefaultArg(0);
415      }
416    }
417  }
418}
419
420/// isCurrentClassName - Determine whether the identifier II is the
421/// name of the class type currently being defined. In the case of
422/// nested classes, this will only return true if II is the name of
423/// the innermost class.
424bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *,
425                              const CXXScopeSpec *SS) {
426  CXXRecordDecl *CurDecl;
427  if (SS && SS->isSet() && !SS->isInvalid()) {
428    DeclContext *DC = computeDeclContext(*SS, true);
429    CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
430  } else
431    CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
432
433  if (CurDecl)
434    return &II == CurDecl->getIdentifier();
435  else
436    return false;
437}
438
439/// \brief Check the validity of a C++ base class specifier.
440///
441/// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
442/// and returns NULL otherwise.
443CXXBaseSpecifier *
444Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
445                         SourceRange SpecifierRange,
446                         bool Virtual, AccessSpecifier Access,
447                         QualType BaseType,
448                         SourceLocation BaseLoc) {
449  // C++ [class.union]p1:
450  //   A union shall not have base classes.
451  if (Class->isUnion()) {
452    Diag(Class->getLocation(), diag::err_base_clause_on_union)
453      << SpecifierRange;
454    return 0;
455  }
456
457  if (BaseType->isDependentType())
458    return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
459                                Class->getTagKind() == RecordDecl::TK_class,
460                                Access, BaseType);
461
462  // Base specifiers must be record types.
463  if (!BaseType->isRecordType()) {
464    Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
465    return 0;
466  }
467
468  // C++ [class.union]p1:
469  //   A union shall not be used as a base class.
470  if (BaseType->isUnionType()) {
471    Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
472    return 0;
473  }
474
475  // C++ [class.derived]p2:
476  //   The class-name in a base-specifier shall not be an incompletely
477  //   defined class.
478  if (RequireCompleteType(BaseLoc, BaseType,
479                          PDiag(diag::err_incomplete_base_class)
480                            << SpecifierRange))
481    return 0;
482
483  // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
484  RecordDecl *BaseDecl = BaseType->getAs<RecordType>()->getDecl();
485  assert(BaseDecl && "Record type has no declaration");
486  BaseDecl = BaseDecl->getDefinition(Context);
487  assert(BaseDecl && "Base type is not incomplete, but has no definition");
488  CXXRecordDecl * CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
489  assert(CXXBaseDecl && "Base type is not a C++ type");
490
491  // C++0x CWG Issue #817 indicates that [[final]] classes shouldn't be bases.
492  if (CXXBaseDecl->hasAttr<FinalAttr>()) {
493    Diag(BaseLoc, diag::err_final_base) << BaseType.getAsString();
494    Diag(CXXBaseDecl->getLocation(), diag::note_previous_decl)
495      << BaseType;
496    return 0;
497  }
498
499  SetClassDeclAttributesFromBase(Class, CXXBaseDecl, Virtual);
500
501  // Create the base specifier.
502  // FIXME: Allocate via ASTContext?
503  return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
504                              Class->getTagKind() == RecordDecl::TK_class,
505                              Access, BaseType);
506}
507
508void Sema::SetClassDeclAttributesFromBase(CXXRecordDecl *Class,
509                                          const CXXRecordDecl *BaseClass,
510                                          bool BaseIsVirtual) {
511  // A class with a non-empty base class is not empty.
512  // FIXME: Standard ref?
513  if (!BaseClass->isEmpty())
514    Class->setEmpty(false);
515
516  // C++ [class.virtual]p1:
517  //   A class that [...] inherits a virtual function is called a polymorphic
518  //   class.
519  if (BaseClass->isPolymorphic())
520    Class->setPolymorphic(true);
521
522  // C++ [dcl.init.aggr]p1:
523  //   An aggregate is [...] a class with [...] no base classes [...].
524  Class->setAggregate(false);
525
526  // C++ [class]p4:
527  //   A POD-struct is an aggregate class...
528  Class->setPOD(false);
529
530  if (BaseIsVirtual) {
531    // C++ [class.ctor]p5:
532    //   A constructor is trivial if its class has no virtual base classes.
533    Class->setHasTrivialConstructor(false);
534
535    // C++ [class.copy]p6:
536    //   A copy constructor is trivial if its class has no virtual base classes.
537    Class->setHasTrivialCopyConstructor(false);
538
539    // C++ [class.copy]p11:
540    //   A copy assignment operator is trivial if its class has no virtual
541    //   base classes.
542    Class->setHasTrivialCopyAssignment(false);
543
544    // C++0x [meta.unary.prop] is_empty:
545    //    T is a class type, but not a union type, with ... no virtual base
546    //    classes
547    Class->setEmpty(false);
548  } else {
549    // C++ [class.ctor]p5:
550    //   A constructor is trivial if all the direct base classes of its
551    //   class have trivial constructors.
552    if (!BaseClass->hasTrivialConstructor())
553      Class->setHasTrivialConstructor(false);
554
555    // C++ [class.copy]p6:
556    //   A copy constructor is trivial if all the direct base classes of its
557    //   class have trivial copy constructors.
558    if (!BaseClass->hasTrivialCopyConstructor())
559      Class->setHasTrivialCopyConstructor(false);
560
561    // C++ [class.copy]p11:
562    //   A copy assignment operator is trivial if all the direct base classes
563    //   of its class have trivial copy assignment operators.
564    if (!BaseClass->hasTrivialCopyAssignment())
565      Class->setHasTrivialCopyAssignment(false);
566  }
567
568  // C++ [class.ctor]p3:
569  //   A destructor is trivial if all the direct base classes of its class
570  //   have trivial destructors.
571  if (!BaseClass->hasTrivialDestructor())
572    Class->setHasTrivialDestructor(false);
573}
574
575/// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
576/// one entry in the base class list of a class specifier, for
577/// example:
578///    class foo : public bar, virtual private baz {
579/// 'public bar' and 'virtual private baz' are each base-specifiers.
580Sema::BaseResult
581Sema::ActOnBaseSpecifier(DeclPtrTy classdecl, SourceRange SpecifierRange,
582                         bool Virtual, AccessSpecifier Access,
583                         TypeTy *basetype, SourceLocation BaseLoc) {
584  if (!classdecl)
585    return true;
586
587  AdjustDeclIfTemplate(classdecl);
588  CXXRecordDecl *Class = cast<CXXRecordDecl>(classdecl.getAs<Decl>());
589  QualType BaseType = GetTypeFromParser(basetype);
590  if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
591                                                      Virtual, Access,
592                                                      BaseType, BaseLoc))
593    return BaseSpec;
594
595  return true;
596}
597
598/// \brief Performs the actual work of attaching the given base class
599/// specifiers to a C++ class.
600bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class, CXXBaseSpecifier **Bases,
601                                unsigned NumBases) {
602 if (NumBases == 0)
603    return false;
604
605  // Used to keep track of which base types we have already seen, so
606  // that we can properly diagnose redundant direct base types. Note
607  // that the key is always the unqualified canonical type of the base
608  // class.
609  std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
610
611  // Copy non-redundant base specifiers into permanent storage.
612  unsigned NumGoodBases = 0;
613  bool Invalid = false;
614  for (unsigned idx = 0; idx < NumBases; ++idx) {
615    QualType NewBaseType
616      = Context.getCanonicalType(Bases[idx]->getType());
617    NewBaseType = NewBaseType.getLocalUnqualifiedType();
618
619    if (KnownBaseTypes[NewBaseType]) {
620      // C++ [class.mi]p3:
621      //   A class shall not be specified as a direct base class of a
622      //   derived class more than once.
623      Diag(Bases[idx]->getSourceRange().getBegin(),
624           diag::err_duplicate_base_class)
625        << KnownBaseTypes[NewBaseType]->getType()
626        << Bases[idx]->getSourceRange();
627
628      // Delete the duplicate base class specifier; we're going to
629      // overwrite its pointer later.
630      Context.Deallocate(Bases[idx]);
631
632      Invalid = true;
633    } else {
634      // Okay, add this new base class.
635      KnownBaseTypes[NewBaseType] = Bases[idx];
636      Bases[NumGoodBases++] = Bases[idx];
637    }
638  }
639
640  // Attach the remaining base class specifiers to the derived class.
641  Class->setBases(Context, Bases, NumGoodBases);
642
643  // Delete the remaining (good) base class specifiers, since their
644  // data has been copied into the CXXRecordDecl.
645  for (unsigned idx = 0; idx < NumGoodBases; ++idx)
646    Context.Deallocate(Bases[idx]);
647
648  return Invalid;
649}
650
651/// ActOnBaseSpecifiers - Attach the given base specifiers to the
652/// class, after checking whether there are any duplicate base
653/// classes.
654void Sema::ActOnBaseSpecifiers(DeclPtrTy ClassDecl, BaseTy **Bases,
655                               unsigned NumBases) {
656  if (!ClassDecl || !Bases || !NumBases)
657    return;
658
659  AdjustDeclIfTemplate(ClassDecl);
660  AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl.getAs<Decl>()),
661                       (CXXBaseSpecifier**)(Bases), NumBases);
662}
663
664/// \brief Determine whether the type \p Derived is a C++ class that is
665/// derived from the type \p Base.
666bool Sema::IsDerivedFrom(QualType Derived, QualType Base) {
667  if (!getLangOptions().CPlusPlus)
668    return false;
669
670  const RecordType *DerivedRT = Derived->getAs<RecordType>();
671  if (!DerivedRT)
672    return false;
673
674  const RecordType *BaseRT = Base->getAs<RecordType>();
675  if (!BaseRT)
676    return false;
677
678  CXXRecordDecl *DerivedRD = cast<CXXRecordDecl>(DerivedRT->getDecl());
679  CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl());
680  return DerivedRD->isDerivedFrom(BaseRD);
681}
682
683/// \brief Determine whether the type \p Derived is a C++ class that is
684/// derived from the type \p Base.
685bool Sema::IsDerivedFrom(QualType Derived, QualType Base, CXXBasePaths &Paths) {
686  if (!getLangOptions().CPlusPlus)
687    return false;
688
689  const RecordType *DerivedRT = Derived->getAs<RecordType>();
690  if (!DerivedRT)
691    return false;
692
693  const RecordType *BaseRT = Base->getAs<RecordType>();
694  if (!BaseRT)
695    return false;
696
697  CXXRecordDecl *DerivedRD = cast<CXXRecordDecl>(DerivedRT->getDecl());
698  CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl());
699  return DerivedRD->isDerivedFrom(BaseRD, Paths);
700}
701
702/// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
703/// conversion (where Derived and Base are class types) is
704/// well-formed, meaning that the conversion is unambiguous (and
705/// that all of the base classes are accessible). Returns true
706/// and emits a diagnostic if the code is ill-formed, returns false
707/// otherwise. Loc is the location where this routine should point to
708/// if there is an error, and Range is the source range to highlight
709/// if there is an error.
710bool
711Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
712                                   unsigned InaccessibleBaseID,
713                                   unsigned AmbigiousBaseConvID,
714                                   SourceLocation Loc, SourceRange Range,
715                                   DeclarationName Name) {
716  // First, determine whether the path from Derived to Base is
717  // ambiguous. This is slightly more expensive than checking whether
718  // the Derived to Base conversion exists, because here we need to
719  // explore multiple paths to determine if there is an ambiguity.
720  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
721                     /*DetectVirtual=*/false);
722  bool DerivationOkay = IsDerivedFrom(Derived, Base, Paths);
723  assert(DerivationOkay &&
724         "Can only be used with a derived-to-base conversion");
725  (void)DerivationOkay;
726
727  if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType())) {
728    if (InaccessibleBaseID == 0)
729      return false;
730    // Check that the base class can be accessed.
731    return CheckBaseClassAccess(Derived, Base, InaccessibleBaseID, Paths, Loc,
732                                Name);
733  }
734
735  // We know that the derived-to-base conversion is ambiguous, and
736  // we're going to produce a diagnostic. Perform the derived-to-base
737  // search just one more time to compute all of the possible paths so
738  // that we can print them out. This is more expensive than any of
739  // the previous derived-to-base checks we've done, but at this point
740  // performance isn't as much of an issue.
741  Paths.clear();
742  Paths.setRecordingPaths(true);
743  bool StillOkay = IsDerivedFrom(Derived, Base, Paths);
744  assert(StillOkay && "Can only be used with a derived-to-base conversion");
745  (void)StillOkay;
746
747  // Build up a textual representation of the ambiguous paths, e.g.,
748  // D -> B -> A, that will be used to illustrate the ambiguous
749  // conversions in the diagnostic. We only print one of the paths
750  // to each base class subobject.
751  std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
752
753  Diag(Loc, AmbigiousBaseConvID)
754  << Derived << Base << PathDisplayStr << Range << Name;
755  return true;
756}
757
758bool
759Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
760                                   SourceLocation Loc, SourceRange Range,
761                                   bool IgnoreAccess) {
762  return CheckDerivedToBaseConversion(Derived, Base,
763                                      IgnoreAccess ? 0 :
764                                        diag::err_conv_to_inaccessible_base,
765                                      diag::err_ambiguous_derived_to_base_conv,
766                                      Loc, Range, DeclarationName());
767}
768
769
770/// @brief Builds a string representing ambiguous paths from a
771/// specific derived class to different subobjects of the same base
772/// class.
773///
774/// This function builds a string that can be used in error messages
775/// to show the different paths that one can take through the
776/// inheritance hierarchy to go from the derived class to different
777/// subobjects of a base class. The result looks something like this:
778/// @code
779/// struct D -> struct B -> struct A
780/// struct D -> struct C -> struct A
781/// @endcode
782std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
783  std::string PathDisplayStr;
784  std::set<unsigned> DisplayedPaths;
785  for (CXXBasePaths::paths_iterator Path = Paths.begin();
786       Path != Paths.end(); ++Path) {
787    if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
788      // We haven't displayed a path to this particular base
789      // class subobject yet.
790      PathDisplayStr += "\n    ";
791      PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
792      for (CXXBasePath::const_iterator Element = Path->begin();
793           Element != Path->end(); ++Element)
794        PathDisplayStr += " -> " + Element->Base->getType().getAsString();
795    }
796  }
797
798  return PathDisplayStr;
799}
800
801//===----------------------------------------------------------------------===//
802// C++ class member Handling
803//===----------------------------------------------------------------------===//
804
805/// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
806/// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
807/// bitfield width if there is one and 'InitExpr' specifies the initializer if
808/// any.
809Sema::DeclPtrTy
810Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
811                               MultiTemplateParamsArg TemplateParameterLists,
812                               ExprTy *BW, ExprTy *InitExpr, bool IsDefinition,
813                               bool Deleted) {
814  const DeclSpec &DS = D.getDeclSpec();
815  DeclarationName Name = GetNameForDeclarator(D);
816  Expr *BitWidth = static_cast<Expr*>(BW);
817  Expr *Init = static_cast<Expr*>(InitExpr);
818  SourceLocation Loc = D.getIdentifierLoc();
819
820  bool isFunc = D.isFunctionDeclarator();
821
822  assert(!DS.isFriendSpecified());
823
824  // C++ 9.2p6: A member shall not be declared to have automatic storage
825  // duration (auto, register) or with the extern storage-class-specifier.
826  // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
827  // data members and cannot be applied to names declared const or static,
828  // and cannot be applied to reference members.
829  switch (DS.getStorageClassSpec()) {
830    case DeclSpec::SCS_unspecified:
831    case DeclSpec::SCS_typedef:
832    case DeclSpec::SCS_static:
833      // FALL THROUGH.
834      break;
835    case DeclSpec::SCS_mutable:
836      if (isFunc) {
837        if (DS.getStorageClassSpecLoc().isValid())
838          Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
839        else
840          Diag(DS.getThreadSpecLoc(), diag::err_mutable_function);
841
842        // FIXME: It would be nicer if the keyword was ignored only for this
843        // declarator. Otherwise we could get follow-up errors.
844        D.getMutableDeclSpec().ClearStorageClassSpecs();
845      } else {
846        QualType T = GetTypeForDeclarator(D, S);
847        diag::kind err = static_cast<diag::kind>(0);
848        if (T->isReferenceType())
849          err = diag::err_mutable_reference;
850        else if (T.isConstQualified())
851          err = diag::err_mutable_const;
852        if (err != 0) {
853          if (DS.getStorageClassSpecLoc().isValid())
854            Diag(DS.getStorageClassSpecLoc(), err);
855          else
856            Diag(DS.getThreadSpecLoc(), err);
857          // FIXME: It would be nicer if the keyword was ignored only for this
858          // declarator. Otherwise we could get follow-up errors.
859          D.getMutableDeclSpec().ClearStorageClassSpecs();
860        }
861      }
862      break;
863    default:
864      if (DS.getStorageClassSpecLoc().isValid())
865        Diag(DS.getStorageClassSpecLoc(),
866             diag::err_storageclass_invalid_for_member);
867      else
868        Diag(DS.getThreadSpecLoc(), diag::err_storageclass_invalid_for_member);
869      D.getMutableDeclSpec().ClearStorageClassSpecs();
870  }
871
872  if (!isFunc &&
873      D.getDeclSpec().getTypeSpecType() == DeclSpec::TST_typename &&
874      D.getNumTypeObjects() == 0) {
875    // Check also for this case:
876    //
877    // typedef int f();
878    // f a;
879    //
880    QualType TDType = GetTypeFromParser(DS.getTypeRep());
881    isFunc = TDType->isFunctionType();
882  }
883
884  bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
885                       DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
886                      !isFunc);
887
888  Decl *Member;
889  if (isInstField) {
890    // FIXME: Check for template parameters!
891    Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D, BitWidth,
892                         AS);
893    assert(Member && "HandleField never returns null");
894  } else {
895    Member = HandleDeclarator(S, D, move(TemplateParameterLists), IsDefinition)
896               .getAs<Decl>();
897    if (!Member) {
898      if (BitWidth) DeleteExpr(BitWidth);
899      return DeclPtrTy();
900    }
901
902    // Non-instance-fields can't have a bitfield.
903    if (BitWidth) {
904      if (Member->isInvalidDecl()) {
905        // don't emit another diagnostic.
906      } else if (isa<VarDecl>(Member)) {
907        // C++ 9.6p3: A bit-field shall not be a static member.
908        // "static member 'A' cannot be a bit-field"
909        Diag(Loc, diag::err_static_not_bitfield)
910          << Name << BitWidth->getSourceRange();
911      } else if (isa<TypedefDecl>(Member)) {
912        // "typedef member 'x' cannot be a bit-field"
913        Diag(Loc, diag::err_typedef_not_bitfield)
914          << Name << BitWidth->getSourceRange();
915      } else {
916        // A function typedef ("typedef int f(); f a;").
917        // C++ 9.6p3: A bit-field shall have integral or enumeration type.
918        Diag(Loc, diag::err_not_integral_type_bitfield)
919          << Name << cast<ValueDecl>(Member)->getType()
920          << BitWidth->getSourceRange();
921      }
922
923      DeleteExpr(BitWidth);
924      BitWidth = 0;
925      Member->setInvalidDecl();
926    }
927
928    Member->setAccess(AS);
929
930    // If we have declared a member function template, set the access of the
931    // templated declaration as well.
932    if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
933      FunTmpl->getTemplatedDecl()->setAccess(AS);
934  }
935
936  assert((Name || isInstField) && "No identifier for non-field ?");
937
938  if (Init)
939    AddInitializerToDecl(DeclPtrTy::make(Member), ExprArg(*this, Init), false);
940  if (Deleted) // FIXME: Source location is not very good.
941    SetDeclDeleted(DeclPtrTy::make(Member), D.getSourceRange().getBegin());
942
943  if (isInstField) {
944    FieldCollector->Add(cast<FieldDecl>(Member));
945    return DeclPtrTy();
946  }
947  return DeclPtrTy::make(Member);
948}
949
950/// ActOnMemInitializer - Handle a C++ member initializer.
951Sema::MemInitResult
952Sema::ActOnMemInitializer(DeclPtrTy ConstructorD,
953                          Scope *S,
954                          const CXXScopeSpec &SS,
955                          IdentifierInfo *MemberOrBase,
956                          TypeTy *TemplateTypeTy,
957                          SourceLocation IdLoc,
958                          SourceLocation LParenLoc,
959                          ExprTy **Args, unsigned NumArgs,
960                          SourceLocation *CommaLocs,
961                          SourceLocation RParenLoc) {
962  if (!ConstructorD)
963    return true;
964
965  AdjustDeclIfTemplate(ConstructorD);
966
967  CXXConstructorDecl *Constructor
968    = dyn_cast<CXXConstructorDecl>(ConstructorD.getAs<Decl>());
969  if (!Constructor) {
970    // The user wrote a constructor initializer on a function that is
971    // not a C++ constructor. Ignore the error for now, because we may
972    // have more member initializers coming; we'll diagnose it just
973    // once in ActOnMemInitializers.
974    return true;
975  }
976
977  CXXRecordDecl *ClassDecl = Constructor->getParent();
978
979  // C++ [class.base.init]p2:
980  //   Names in a mem-initializer-id are looked up in the scope of the
981  //   constructor’s class and, if not found in that scope, are looked
982  //   up in the scope containing the constructor’s
983  //   definition. [Note: if the constructor’s class contains a member
984  //   with the same name as a direct or virtual base class of the
985  //   class, a mem-initializer-id naming the member or base class and
986  //   composed of a single identifier refers to the class member. A
987  //   mem-initializer-id for the hidden base class may be specified
988  //   using a qualified name. ]
989  if (!SS.getScopeRep() && !TemplateTypeTy) {
990    // Look for a member, first.
991    FieldDecl *Member = 0;
992    DeclContext::lookup_result Result
993      = ClassDecl->lookup(MemberOrBase);
994    if (Result.first != Result.second)
995      Member = dyn_cast<FieldDecl>(*Result.first);
996
997    // FIXME: Handle members of an anonymous union.
998
999    if (Member)
1000      return BuildMemberInitializer(Member, (Expr**)Args, NumArgs, IdLoc,
1001                                    LParenLoc, RParenLoc);
1002  }
1003  // It didn't name a member, so see if it names a class.
1004  QualType BaseType;
1005
1006  TypeSourceInfo *TInfo = 0;
1007  if (TemplateTypeTy)
1008    BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
1009  else
1010    BaseType = QualType::getFromOpaquePtr(getTypeName(*MemberOrBase, IdLoc,
1011                                                      S, &SS));
1012  if (BaseType.isNull())
1013    return Diag(IdLoc, diag::err_mem_init_not_member_or_class)
1014      << MemberOrBase << SourceRange(IdLoc, RParenLoc);
1015
1016  if (!TInfo)
1017    TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
1018
1019  return BuildBaseInitializer(BaseType, TInfo, (Expr **)Args, NumArgs,
1020                              LParenLoc, RParenLoc, ClassDecl);
1021}
1022
1023/// Checks an initializer expression for use of uninitialized fields, such as
1024/// containing the field that is being initialized. Returns true if there is an
1025/// uninitialized field was used an updates the SourceLocation parameter; false
1026/// otherwise.
1027static bool InitExprContainsUninitializedFields(const Stmt* S,
1028                                                const FieldDecl* LhsField,
1029                                                SourceLocation* L) {
1030  const MemberExpr* ME = dyn_cast<MemberExpr>(S);
1031  if (ME) {
1032    const NamedDecl* RhsField = ME->getMemberDecl();
1033    if (RhsField == LhsField) {
1034      // Initializing a field with itself. Throw a warning.
1035      // But wait; there are exceptions!
1036      // Exception #1:  The field may not belong to this record.
1037      // e.g. Foo(const Foo& rhs) : A(rhs.A) {}
1038      const Expr* base = ME->getBase();
1039      if (base != NULL && !isa<CXXThisExpr>(base->IgnoreParenCasts())) {
1040        // Even though the field matches, it does not belong to this record.
1041        return false;
1042      }
1043      // None of the exceptions triggered; return true to indicate an
1044      // uninitialized field was used.
1045      *L = ME->getMemberLoc();
1046      return true;
1047    }
1048  }
1049  bool found = false;
1050  for (Stmt::const_child_iterator it = S->child_begin();
1051       it != S->child_end() && found == false;
1052       ++it) {
1053    if (isa<CallExpr>(S)) {
1054      // Do not descend into function calls or constructors, as the use
1055      // of an uninitialized field may be valid. One would have to inspect
1056      // the contents of the function/ctor to determine if it is safe or not.
1057      // i.e. Pass-by-value is never safe, but pass-by-reference and pointers
1058      // may be safe, depending on what the function/ctor does.
1059      continue;
1060    }
1061    found = InitExprContainsUninitializedFields(*it, LhsField, L);
1062  }
1063  return found;
1064}
1065
1066Sema::MemInitResult
1067Sema::BuildMemberInitializer(FieldDecl *Member, Expr **Args,
1068                             unsigned NumArgs, SourceLocation IdLoc,
1069                             SourceLocation LParenLoc,
1070                             SourceLocation RParenLoc) {
1071  // FIXME: CXXBaseOrMemberInitializer should only contain a single
1072  // subexpression so we can wrap it in a CXXExprWithTemporaries if necessary.
1073  ExprTemporaries.clear();
1074
1075  // Diagnose value-uses of fields to initialize themselves, e.g.
1076  //   foo(foo)
1077  // where foo is not also a parameter to the constructor.
1078  // TODO: implement -Wuninitialized and fold this into that framework.
1079  for (unsigned i = 0; i < NumArgs; ++i) {
1080    SourceLocation L;
1081    if (InitExprContainsUninitializedFields(Args[i], Member, &L)) {
1082      // FIXME: Return true in the case when other fields are used before being
1083      // uninitialized. For example, let this field be the i'th field. When
1084      // initializing the i'th field, throw a warning if any of the >= i'th
1085      // fields are used, as they are not yet initialized.
1086      // Right now we are only handling the case where the i'th field uses
1087      // itself in its initializer.
1088      Diag(L, diag::warn_field_is_uninit);
1089    }
1090  }
1091
1092  bool HasDependentArg = false;
1093  for (unsigned i = 0; i < NumArgs; i++)
1094    HasDependentArg |= Args[i]->isTypeDependent();
1095
1096  CXXConstructorDecl *C = 0;
1097  QualType FieldType = Member->getType();
1098  if (const ArrayType *Array = Context.getAsArrayType(FieldType))
1099    FieldType = Array->getElementType();
1100  if (FieldType->isDependentType()) {
1101    // Can't check init for dependent type.
1102  } else if (FieldType->isRecordType()) {
1103    // Member is a record (struct/union/class), so pass the initializer
1104    // arguments down to the record's constructor.
1105    if (!HasDependentArg) {
1106      ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(*this);
1107
1108      C = PerformInitializationByConstructor(FieldType,
1109                                             MultiExprArg(*this,
1110                                                          (void**)Args,
1111                                                          NumArgs),
1112                                             IdLoc,
1113                                             SourceRange(IdLoc, RParenLoc),
1114                                             Member->getDeclName(),
1115                  InitializationKind::CreateDirect(IdLoc, LParenLoc, RParenLoc),
1116                                             ConstructorArgs);
1117
1118      if (C) {
1119        // Take over the constructor arguments as our own.
1120        NumArgs = ConstructorArgs.size();
1121        Args = (Expr **)ConstructorArgs.take();
1122      }
1123    }
1124  } else if (NumArgs != 1 && NumArgs != 0) {
1125    // The member type is not a record type (or an array of record
1126    // types), so it can be only be default- or copy-initialized.
1127    return Diag(IdLoc, diag::err_mem_initializer_mismatch)
1128                << Member->getDeclName() << SourceRange(IdLoc, RParenLoc);
1129  } else if (!HasDependentArg) {
1130    Expr *NewExp;
1131    if (NumArgs == 0) {
1132      if (FieldType->isReferenceType()) {
1133        Diag(IdLoc, diag::err_null_intialized_reference_member)
1134              << Member->getDeclName();
1135        return Diag(Member->getLocation(), diag::note_declared_at);
1136      }
1137      NewExp = new (Context) CXXZeroInitValueExpr(FieldType, IdLoc, RParenLoc);
1138      NumArgs = 1;
1139    }
1140    else
1141      NewExp = (Expr*)Args[0];
1142    if (PerformCopyInitialization(NewExp, FieldType, AA_Passing))
1143      return true;
1144    Args[0] = NewExp;
1145  }
1146
1147  // FIXME: CXXBaseOrMemberInitializer should only contain a single
1148  // subexpression so we can wrap it in a CXXExprWithTemporaries if necessary.
1149  ExprTemporaries.clear();
1150
1151  // FIXME: Perform direct initialization of the member.
1152  return new (Context) CXXBaseOrMemberInitializer(Context, Member, IdLoc,
1153                                                  C, LParenLoc, (Expr **)Args,
1154                                                  NumArgs, RParenLoc);
1155}
1156
1157Sema::MemInitResult
1158Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
1159                           Expr **Args, unsigned NumArgs,
1160                           SourceLocation LParenLoc, SourceLocation RParenLoc,
1161                           CXXRecordDecl *ClassDecl) {
1162  bool HasDependentArg = false;
1163  for (unsigned i = 0; i < NumArgs; i++)
1164    HasDependentArg |= Args[i]->isTypeDependent();
1165
1166  SourceLocation BaseLoc = BaseTInfo->getTypeLoc().getSourceRange().getBegin();
1167  if (!BaseType->isDependentType()) {
1168    if (!BaseType->isRecordType())
1169      return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
1170        << BaseType << BaseTInfo->getTypeLoc().getSourceRange();
1171
1172    // C++ [class.base.init]p2:
1173    //   [...] Unless the mem-initializer-id names a nonstatic data
1174    //   member of the constructor’s class or a direct or virtual base
1175    //   of that class, the mem-initializer is ill-formed. A
1176    //   mem-initializer-list can initialize a base class using any
1177    //   name that denotes that base class type.
1178
1179    // First, check for a direct base class.
1180    const CXXBaseSpecifier *DirectBaseSpec = 0;
1181    for (CXXRecordDecl::base_class_const_iterator Base =
1182         ClassDecl->bases_begin(); Base != ClassDecl->bases_end(); ++Base) {
1183      if (Context.hasSameUnqualifiedType(BaseType, Base->getType())) {
1184        // We found a direct base of this type. That's what we're
1185        // initializing.
1186        DirectBaseSpec = &*Base;
1187        break;
1188      }
1189    }
1190
1191    // Check for a virtual base class.
1192    // FIXME: We might be able to short-circuit this if we know in advance that
1193    // there are no virtual bases.
1194    const CXXBaseSpecifier *VirtualBaseSpec = 0;
1195    if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
1196      // We haven't found a base yet; search the class hierarchy for a
1197      // virtual base class.
1198      CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1199                         /*DetectVirtual=*/false);
1200      if (IsDerivedFrom(Context.getTypeDeclType(ClassDecl), BaseType, Paths)) {
1201        for (CXXBasePaths::paths_iterator Path = Paths.begin();
1202             Path != Paths.end(); ++Path) {
1203          if (Path->back().Base->isVirtual()) {
1204            VirtualBaseSpec = Path->back().Base;
1205            break;
1206          }
1207        }
1208      }
1209    }
1210
1211    // C++ [base.class.init]p2:
1212    //   If a mem-initializer-id is ambiguous because it designates both
1213    //   a direct non-virtual base class and an inherited virtual base
1214    //   class, the mem-initializer is ill-formed.
1215    if (DirectBaseSpec && VirtualBaseSpec)
1216      return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
1217        << BaseType << BaseTInfo->getTypeLoc().getSourceRange();
1218    // C++ [base.class.init]p2:
1219    // Unless the mem-initializer-id names a nonstatic data membeer of the
1220    // constructor's class ot a direst or virtual base of that class, the
1221    // mem-initializer is ill-formed.
1222    if (!DirectBaseSpec && !VirtualBaseSpec)
1223      return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
1224        << BaseType << ClassDecl->getNameAsCString()
1225        << BaseTInfo->getTypeLoc().getSourceRange();
1226  }
1227
1228  CXXConstructorDecl *C = 0;
1229  if (!BaseType->isDependentType() && !HasDependentArg) {
1230    DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(
1231                      Context.getCanonicalType(BaseType).getUnqualifiedType());
1232    ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(*this);
1233
1234    C = PerformInitializationByConstructor(BaseType,
1235                                           MultiExprArg(*this,
1236                                                        (void**)Args, NumArgs),
1237                                           BaseLoc,
1238                                           SourceRange(BaseLoc, RParenLoc),
1239                                           Name,
1240                InitializationKind::CreateDirect(BaseLoc, LParenLoc, RParenLoc),
1241                                           ConstructorArgs);
1242    if (C) {
1243      // Take over the constructor arguments as our own.
1244      NumArgs = ConstructorArgs.size();
1245      Args = (Expr **)ConstructorArgs.take();
1246    }
1247  }
1248
1249  // FIXME: CXXBaseOrMemberInitializer should only contain a single
1250  // subexpression so we can wrap it in a CXXExprWithTemporaries if necessary.
1251  ExprTemporaries.clear();
1252
1253  return new (Context) CXXBaseOrMemberInitializer(Context, BaseTInfo, C,
1254                                                  LParenLoc, (Expr **)Args,
1255                                                  NumArgs, RParenLoc);
1256}
1257
1258bool
1259Sema::SetBaseOrMemberInitializers(CXXConstructorDecl *Constructor,
1260                              CXXBaseOrMemberInitializer **Initializers,
1261                              unsigned NumInitializers,
1262                              bool IsImplicitConstructor) {
1263  // We need to build the initializer AST according to order of construction
1264  // and not what user specified in the Initializers list.
1265  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Constructor->getDeclContext());
1266  llvm::SmallVector<CXXBaseOrMemberInitializer*, 32> AllToInit;
1267  llvm::DenseMap<const void *, CXXBaseOrMemberInitializer*> AllBaseFields;
1268  bool HasDependentBaseInit = false;
1269  bool HadError = false;
1270
1271  for (unsigned i = 0; i < NumInitializers; i++) {
1272    CXXBaseOrMemberInitializer *Member = Initializers[i];
1273    if (Member->isBaseInitializer()) {
1274      if (Member->getBaseClass()->isDependentType())
1275        HasDependentBaseInit = true;
1276      AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
1277    } else {
1278      AllBaseFields[Member->getMember()] = Member;
1279    }
1280  }
1281
1282  if (HasDependentBaseInit) {
1283    // FIXME. This does not preserve the ordering of the initializers.
1284    // Try (with -Wreorder)
1285    // template<class X> struct A {};
1286    // template<class X> struct B : A<X> {
1287    //   B() : x1(10), A<X>() {}
1288    //   int x1;
1289    // };
1290    // B<int> x;
1291    // On seeing one dependent type, we should essentially exit this routine
1292    // while preserving user-declared initializer list. When this routine is
1293    // called during instantiatiation process, this routine will rebuild the
1294    // ordered initializer list correctly.
1295
1296    // If we have a dependent base initialization, we can't determine the
1297    // association between initializers and bases; just dump the known
1298    // initializers into the list, and don't try to deal with other bases.
1299    for (unsigned i = 0; i < NumInitializers; i++) {
1300      CXXBaseOrMemberInitializer *Member = Initializers[i];
1301      if (Member->isBaseInitializer())
1302        AllToInit.push_back(Member);
1303    }
1304  } else {
1305    // Push virtual bases before others.
1306    for (CXXRecordDecl::base_class_iterator VBase =
1307         ClassDecl->vbases_begin(),
1308         E = ClassDecl->vbases_end(); VBase != E; ++VBase) {
1309      if (VBase->getType()->isDependentType())
1310        continue;
1311      if (CXXBaseOrMemberInitializer *Value
1312            = AllBaseFields.lookup(VBase->getType()->getAs<RecordType>())) {
1313        AllToInit.push_back(Value);
1314      }
1315      else {
1316        CXXRecordDecl *VBaseDecl =
1317          cast<CXXRecordDecl>(VBase->getType()->getAs<RecordType>()->getDecl());
1318        assert(VBaseDecl && "SetBaseOrMemberInitializers - VBaseDecl null");
1319        CXXConstructorDecl *Ctor = VBaseDecl->getDefaultConstructor(Context);
1320        if (!Ctor) {
1321          Diag(Constructor->getLocation(), diag::err_missing_default_ctor)
1322            << (int)IsImplicitConstructor << Context.getTagDeclType(ClassDecl)
1323            << 0 << VBase->getType();
1324          Diag(VBaseDecl->getLocation(), diag::note_previous_decl)
1325            << Context.getTagDeclType(VBaseDecl);
1326          HadError = true;
1327          continue;
1328        }
1329
1330        ASTOwningVector<&ActionBase::DeleteExpr> CtorArgs(*this);
1331        if (CompleteConstructorCall(Ctor, MultiExprArg(*this, 0, 0),
1332                                    Constructor->getLocation(), CtorArgs))
1333          continue;
1334
1335        MarkDeclarationReferenced(Constructor->getLocation(), Ctor);
1336
1337        // FIXME: CXXBaseOrMemberInitializer should only contain a single
1338        // subexpression so we can wrap it in a CXXExprWithTemporaries if
1339        // necessary.
1340        // FIXME: Is there any better source-location information we can give?
1341        ExprTemporaries.clear();
1342        CXXBaseOrMemberInitializer *Member =
1343          new (Context) CXXBaseOrMemberInitializer(Context,
1344                             Context.getTrivialTypeSourceInfo(VBase->getType(),
1345                                                              SourceLocation()),
1346                                                   Ctor,
1347                                                   SourceLocation(),
1348                                                   CtorArgs.takeAs<Expr>(),
1349                                                   CtorArgs.size(),
1350                                                   SourceLocation());
1351        AllToInit.push_back(Member);
1352      }
1353    }
1354
1355    for (CXXRecordDecl::base_class_iterator Base =
1356         ClassDecl->bases_begin(),
1357         E = ClassDecl->bases_end(); Base != E; ++Base) {
1358      // Virtuals are in the virtual base list and already constructed.
1359      if (Base->isVirtual())
1360        continue;
1361      // Skip dependent types.
1362      if (Base->getType()->isDependentType())
1363        continue;
1364      if (CXXBaseOrMemberInitializer *Value
1365            = AllBaseFields.lookup(Base->getType()->getAs<RecordType>())) {
1366        AllToInit.push_back(Value);
1367      }
1368      else {
1369        CXXRecordDecl *BaseDecl =
1370          cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
1371        assert(BaseDecl && "SetBaseOrMemberInitializers - BaseDecl null");
1372         CXXConstructorDecl *Ctor = BaseDecl->getDefaultConstructor(Context);
1373        if (!Ctor) {
1374          Diag(Constructor->getLocation(), diag::err_missing_default_ctor)
1375            << (int)IsImplicitConstructor << Context.getTagDeclType(ClassDecl)
1376            << 0 << Base->getType();
1377          Diag(BaseDecl->getLocation(), diag::note_previous_decl)
1378            << Context.getTagDeclType(BaseDecl);
1379          HadError = true;
1380          continue;
1381        }
1382
1383        ASTOwningVector<&ActionBase::DeleteExpr> CtorArgs(*this);
1384        if (CompleteConstructorCall(Ctor, MultiExprArg(*this, 0, 0),
1385                                     Constructor->getLocation(), CtorArgs))
1386          continue;
1387
1388        MarkDeclarationReferenced(Constructor->getLocation(), Ctor);
1389
1390        // FIXME: CXXBaseOrMemberInitializer should only contain a single
1391        // subexpression so we can wrap it in a CXXExprWithTemporaries if
1392        // necessary.
1393        // FIXME: Is there any better source-location information we can give?
1394        ExprTemporaries.clear();
1395        CXXBaseOrMemberInitializer *Member =
1396          new (Context) CXXBaseOrMemberInitializer(Context,
1397                             Context.getTrivialTypeSourceInfo(Base->getType(),
1398                                                              SourceLocation()),
1399                                                   Ctor,
1400                                                   SourceLocation(),
1401                                                   CtorArgs.takeAs<Expr>(),
1402                                                   CtorArgs.size(),
1403                                                   SourceLocation());
1404        AllToInit.push_back(Member);
1405      }
1406    }
1407  }
1408
1409  // non-static data members.
1410  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
1411       E = ClassDecl->field_end(); Field != E; ++Field) {
1412    if ((*Field)->isAnonymousStructOrUnion()) {
1413      if (const RecordType *FieldClassType =
1414          Field->getType()->getAs<RecordType>()) {
1415        CXXRecordDecl *FieldClassDecl
1416          = cast<CXXRecordDecl>(FieldClassType->getDecl());
1417        for (RecordDecl::field_iterator FA = FieldClassDecl->field_begin(),
1418            EA = FieldClassDecl->field_end(); FA != EA; FA++) {
1419          if (CXXBaseOrMemberInitializer *Value = AllBaseFields.lookup(*FA)) {
1420            // 'Member' is the anonymous union field and 'AnonUnionMember' is
1421            // set to the anonymous union data member used in the initializer
1422            // list.
1423            Value->setMember(*Field);
1424            Value->setAnonUnionMember(*FA);
1425            AllToInit.push_back(Value);
1426            break;
1427          }
1428        }
1429      }
1430      continue;
1431    }
1432    if (CXXBaseOrMemberInitializer *Value = AllBaseFields.lookup(*Field)) {
1433      AllToInit.push_back(Value);
1434      continue;
1435    }
1436
1437    if ((*Field)->getType()->isDependentType())
1438      continue;
1439
1440    QualType FT = Context.getBaseElementType((*Field)->getType());
1441    if (const RecordType* RT = FT->getAs<RecordType>()) {
1442      CXXConstructorDecl *Ctor =
1443        cast<CXXRecordDecl>(RT->getDecl())->getDefaultConstructor(Context);
1444      if (!Ctor) {
1445        Diag(Constructor->getLocation(), diag::err_missing_default_ctor)
1446          << (int)IsImplicitConstructor << Context.getTagDeclType(ClassDecl)
1447          << 1 << (*Field)->getDeclName();
1448        Diag(Field->getLocation(), diag::note_field_decl);
1449        Diag(RT->getDecl()->getLocation(), diag::note_previous_decl)
1450          << Context.getTagDeclType(RT->getDecl());
1451        HadError = true;
1452        continue;
1453      }
1454
1455      if (FT.isConstQualified() && Ctor->isTrivial()) {
1456        Diag(Constructor->getLocation(), diag::err_unintialized_member_in_ctor)
1457          << (int)IsImplicitConstructor << Context.getTagDeclType(ClassDecl)
1458          << 1 << (*Field)->getDeclName();
1459        Diag((*Field)->getLocation(), diag::note_declared_at);
1460        HadError = true;
1461      }
1462
1463      // Don't create initializers for trivial constructors, since they don't
1464      // actually need to be run.
1465      if (Ctor->isTrivial())
1466        continue;
1467
1468      ASTOwningVector<&ActionBase::DeleteExpr> CtorArgs(*this);
1469      if (CompleteConstructorCall(Ctor, MultiExprArg(*this, 0, 0),
1470                                  Constructor->getLocation(), CtorArgs))
1471        continue;
1472
1473      // FIXME: CXXBaseOrMemberInitializer should only contain a single
1474      // subexpression so we can wrap it in a CXXExprWithTemporaries if necessary.
1475      ExprTemporaries.clear();
1476      CXXBaseOrMemberInitializer *Member =
1477        new (Context) CXXBaseOrMemberInitializer(Context,
1478                                                 *Field, SourceLocation(),
1479                                                 Ctor,
1480                                                 SourceLocation(),
1481                                                 CtorArgs.takeAs<Expr>(),
1482                                                 CtorArgs.size(),
1483                                                 SourceLocation());
1484
1485      AllToInit.push_back(Member);
1486      MarkDeclarationReferenced(Constructor->getLocation(), Ctor);
1487    }
1488    else if (FT->isReferenceType()) {
1489      Diag(Constructor->getLocation(), diag::err_unintialized_member_in_ctor)
1490        << (int)IsImplicitConstructor << Context.getTagDeclType(ClassDecl)
1491        << 0 << (*Field)->getDeclName();
1492      Diag((*Field)->getLocation(), diag::note_declared_at);
1493      HadError = true;
1494    }
1495    else if (FT.isConstQualified()) {
1496      Diag(Constructor->getLocation(), diag::err_unintialized_member_in_ctor)
1497        << (int)IsImplicitConstructor << Context.getTagDeclType(ClassDecl)
1498        << 1 << (*Field)->getDeclName();
1499      Diag((*Field)->getLocation(), diag::note_declared_at);
1500      HadError = true;
1501    }
1502  }
1503
1504  NumInitializers = AllToInit.size();
1505  if (NumInitializers > 0) {
1506    Constructor->setNumBaseOrMemberInitializers(NumInitializers);
1507    CXXBaseOrMemberInitializer **baseOrMemberInitializers =
1508      new (Context) CXXBaseOrMemberInitializer*[NumInitializers];
1509
1510    Constructor->setBaseOrMemberInitializers(baseOrMemberInitializers);
1511    for (unsigned Idx = 0; Idx < NumInitializers; ++Idx)
1512      baseOrMemberInitializers[Idx] = AllToInit[Idx];
1513  }
1514
1515  return HadError;
1516}
1517
1518static void *GetKeyForTopLevelField(FieldDecl *Field) {
1519  // For anonymous unions, use the class declaration as the key.
1520  if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
1521    if (RT->getDecl()->isAnonymousStructOrUnion())
1522      return static_cast<void *>(RT->getDecl());
1523  }
1524  return static_cast<void *>(Field);
1525}
1526
1527static void *GetKeyForBase(QualType BaseType) {
1528  if (const RecordType *RT = BaseType->getAs<RecordType>())
1529    return (void *)RT;
1530
1531  assert(0 && "Unexpected base type!");
1532  return 0;
1533}
1534
1535static void *GetKeyForMember(CXXBaseOrMemberInitializer *Member,
1536                             bool MemberMaybeAnon = false) {
1537  // For fields injected into the class via declaration of an anonymous union,
1538  // use its anonymous union class declaration as the unique key.
1539  if (Member->isMemberInitializer()) {
1540    FieldDecl *Field = Member->getMember();
1541
1542    // After SetBaseOrMemberInitializers call, Field is the anonymous union
1543    // data member of the class. Data member used in the initializer list is
1544    // in AnonUnionMember field.
1545    if (MemberMaybeAnon && Field->isAnonymousStructOrUnion())
1546      Field = Member->getAnonUnionMember();
1547    if (Field->getDeclContext()->isRecord()) {
1548      RecordDecl *RD = cast<RecordDecl>(Field->getDeclContext());
1549      if (RD->isAnonymousStructOrUnion())
1550        return static_cast<void *>(RD);
1551    }
1552    return static_cast<void *>(Field);
1553  }
1554
1555  return GetKeyForBase(QualType(Member->getBaseClass(), 0));
1556}
1557
1558/// ActOnMemInitializers - Handle the member initializers for a constructor.
1559void Sema::ActOnMemInitializers(DeclPtrTy ConstructorDecl,
1560                                SourceLocation ColonLoc,
1561                                MemInitTy **MemInits, unsigned NumMemInits) {
1562  if (!ConstructorDecl)
1563    return;
1564
1565  AdjustDeclIfTemplate(ConstructorDecl);
1566
1567  CXXConstructorDecl *Constructor
1568    = dyn_cast<CXXConstructorDecl>(ConstructorDecl.getAs<Decl>());
1569
1570  if (!Constructor) {
1571    Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
1572    return;
1573  }
1574
1575  if (!Constructor->isDependentContext()) {
1576    llvm::DenseMap<void*, CXXBaseOrMemberInitializer *>Members;
1577    bool err = false;
1578    for (unsigned i = 0; i < NumMemInits; i++) {
1579      CXXBaseOrMemberInitializer *Member =
1580        static_cast<CXXBaseOrMemberInitializer*>(MemInits[i]);
1581      void *KeyToMember = GetKeyForMember(Member);
1582      CXXBaseOrMemberInitializer *&PrevMember = Members[KeyToMember];
1583      if (!PrevMember) {
1584        PrevMember = Member;
1585        continue;
1586      }
1587      if (FieldDecl *Field = Member->getMember())
1588        Diag(Member->getSourceLocation(),
1589             diag::error_multiple_mem_initialization)
1590          << Field->getNameAsString()
1591          << Member->getSourceRange();
1592      else {
1593        Type *BaseClass = Member->getBaseClass();
1594        assert(BaseClass && "ActOnMemInitializers - neither field or base");
1595        Diag(Member->getSourceLocation(),
1596             diag::error_multiple_base_initialization)
1597          << QualType(BaseClass, 0)
1598          << Member->getSourceRange();
1599      }
1600      Diag(PrevMember->getSourceLocation(), diag::note_previous_initializer)
1601        << 0;
1602      err = true;
1603    }
1604
1605    if (err)
1606      return;
1607  }
1608
1609  SetBaseOrMemberInitializers(Constructor,
1610                      reinterpret_cast<CXXBaseOrMemberInitializer **>(MemInits),
1611                      NumMemInits, false);
1612
1613  if (Constructor->isDependentContext())
1614    return;
1615
1616  if (Diags.getDiagnosticLevel(diag::warn_base_initialized) ==
1617      Diagnostic::Ignored &&
1618      Diags.getDiagnosticLevel(diag::warn_field_initialized) ==
1619      Diagnostic::Ignored)
1620    return;
1621
1622  // Also issue warning if order of ctor-initializer list does not match order
1623  // of 1) base class declarations and 2) order of non-static data members.
1624  llvm::SmallVector<const void*, 32> AllBaseOrMembers;
1625
1626  CXXRecordDecl *ClassDecl
1627    = cast<CXXRecordDecl>(Constructor->getDeclContext());
1628  // Push virtual bases before others.
1629  for (CXXRecordDecl::base_class_iterator VBase =
1630       ClassDecl->vbases_begin(),
1631       E = ClassDecl->vbases_end(); VBase != E; ++VBase)
1632    AllBaseOrMembers.push_back(GetKeyForBase(VBase->getType()));
1633
1634  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
1635       E = ClassDecl->bases_end(); Base != E; ++Base) {
1636    // Virtuals are alread in the virtual base list and are constructed
1637    // first.
1638    if (Base->isVirtual())
1639      continue;
1640    AllBaseOrMembers.push_back(GetKeyForBase(Base->getType()));
1641  }
1642
1643  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
1644       E = ClassDecl->field_end(); Field != E; ++Field)
1645    AllBaseOrMembers.push_back(GetKeyForTopLevelField(*Field));
1646
1647  int Last = AllBaseOrMembers.size();
1648  int curIndex = 0;
1649  CXXBaseOrMemberInitializer *PrevMember = 0;
1650  for (unsigned i = 0; i < NumMemInits; i++) {
1651    CXXBaseOrMemberInitializer *Member =
1652      static_cast<CXXBaseOrMemberInitializer*>(MemInits[i]);
1653    void *MemberInCtorList = GetKeyForMember(Member, true);
1654
1655    for (; curIndex < Last; curIndex++)
1656      if (MemberInCtorList == AllBaseOrMembers[curIndex])
1657        break;
1658    if (curIndex == Last) {
1659      assert(PrevMember && "Member not in member list?!");
1660      // Initializer as specified in ctor-initializer list is out of order.
1661      // Issue a warning diagnostic.
1662      if (PrevMember->isBaseInitializer()) {
1663        // Diagnostics is for an initialized base class.
1664        Type *BaseClass = PrevMember->getBaseClass();
1665        Diag(PrevMember->getSourceLocation(),
1666             diag::warn_base_initialized)
1667          << QualType(BaseClass, 0);
1668      } else {
1669        FieldDecl *Field = PrevMember->getMember();
1670        Diag(PrevMember->getSourceLocation(),
1671             diag::warn_field_initialized)
1672          << Field->getNameAsString();
1673      }
1674      // Also the note!
1675      if (FieldDecl *Field = Member->getMember())
1676        Diag(Member->getSourceLocation(),
1677             diag::note_fieldorbase_initialized_here) << 0
1678          << Field->getNameAsString();
1679      else {
1680        Type *BaseClass = Member->getBaseClass();
1681        Diag(Member->getSourceLocation(),
1682             diag::note_fieldorbase_initialized_here) << 1
1683          << QualType(BaseClass, 0);
1684      }
1685      for (curIndex = 0; curIndex < Last; curIndex++)
1686        if (MemberInCtorList == AllBaseOrMembers[curIndex])
1687          break;
1688    }
1689    PrevMember = Member;
1690  }
1691}
1692
1693void
1694Sema::MarkBaseAndMemberDestructorsReferenced(CXXDestructorDecl *Destructor) {
1695  // Ignore dependent destructors.
1696  if (Destructor->isDependentContext())
1697    return;
1698
1699  CXXRecordDecl *ClassDecl = Destructor->getParent();
1700
1701  // Non-static data members.
1702  for (CXXRecordDecl::field_iterator I = ClassDecl->field_begin(),
1703       E = ClassDecl->field_end(); I != E; ++I) {
1704    FieldDecl *Field = *I;
1705
1706    QualType FieldType = Context.getBaseElementType(Field->getType());
1707
1708    const RecordType* RT = FieldType->getAs<RecordType>();
1709    if (!RT)
1710      continue;
1711
1712    CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
1713    if (FieldClassDecl->hasTrivialDestructor())
1714      continue;
1715
1716    const CXXDestructorDecl *Dtor = FieldClassDecl->getDestructor(Context);
1717    MarkDeclarationReferenced(Destructor->getLocation(),
1718                              const_cast<CXXDestructorDecl*>(Dtor));
1719  }
1720
1721  // Bases.
1722  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
1723       E = ClassDecl->bases_end(); Base != E; ++Base) {
1724    // Ignore virtual bases.
1725    if (Base->isVirtual())
1726      continue;
1727
1728    // Ignore trivial destructors.
1729    CXXRecordDecl *BaseClassDecl
1730      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
1731    if (BaseClassDecl->hasTrivialDestructor())
1732      continue;
1733
1734    const CXXDestructorDecl *Dtor = BaseClassDecl->getDestructor(Context);
1735    MarkDeclarationReferenced(Destructor->getLocation(),
1736                              const_cast<CXXDestructorDecl*>(Dtor));
1737  }
1738
1739  // Virtual bases.
1740  for (CXXRecordDecl::base_class_iterator VBase = ClassDecl->vbases_begin(),
1741       E = ClassDecl->vbases_end(); VBase != E; ++VBase) {
1742    // Ignore trivial destructors.
1743    CXXRecordDecl *BaseClassDecl
1744      = cast<CXXRecordDecl>(VBase->getType()->getAs<RecordType>()->getDecl());
1745    if (BaseClassDecl->hasTrivialDestructor())
1746      continue;
1747
1748    const CXXDestructorDecl *Dtor = BaseClassDecl->getDestructor(Context);
1749    MarkDeclarationReferenced(Destructor->getLocation(),
1750                              const_cast<CXXDestructorDecl*>(Dtor));
1751  }
1752}
1753
1754void Sema::ActOnDefaultCtorInitializers(DeclPtrTy CDtorDecl) {
1755  if (!CDtorDecl)
1756    return;
1757
1758  AdjustDeclIfTemplate(CDtorDecl);
1759
1760  if (CXXConstructorDecl *Constructor
1761      = dyn_cast<CXXConstructorDecl>(CDtorDecl.getAs<Decl>()))
1762    SetBaseOrMemberInitializers(Constructor, 0, 0, false);
1763}
1764
1765namespace {
1766  /// PureVirtualMethodCollector - traverses a class and its superclasses
1767  /// and determines if it has any pure virtual methods.
1768  class PureVirtualMethodCollector {
1769    ASTContext &Context;
1770
1771  public:
1772    typedef llvm::SmallVector<const CXXMethodDecl*, 8> MethodList;
1773
1774  private:
1775    MethodList Methods;
1776
1777    void Collect(const CXXRecordDecl* RD, MethodList& Methods);
1778
1779  public:
1780    PureVirtualMethodCollector(ASTContext &Ctx, const CXXRecordDecl* RD)
1781      : Context(Ctx) {
1782
1783      MethodList List;
1784      Collect(RD, List);
1785
1786      // Copy the temporary list to methods, and make sure to ignore any
1787      // null entries.
1788      for (size_t i = 0, e = List.size(); i != e; ++i) {
1789        if (List[i])
1790          Methods.push_back(List[i]);
1791      }
1792    }
1793
1794    bool empty() const { return Methods.empty(); }
1795
1796    MethodList::const_iterator methods_begin() { return Methods.begin(); }
1797    MethodList::const_iterator methods_end() { return Methods.end(); }
1798  };
1799
1800  void PureVirtualMethodCollector::Collect(const CXXRecordDecl* RD,
1801                                           MethodList& Methods) {
1802    // First, collect the pure virtual methods for the base classes.
1803    for (CXXRecordDecl::base_class_const_iterator Base = RD->bases_begin(),
1804         BaseEnd = RD->bases_end(); Base != BaseEnd; ++Base) {
1805      if (const RecordType *RT = Base->getType()->getAs<RecordType>()) {
1806        const CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(RT->getDecl());
1807        if (BaseDecl && BaseDecl->isAbstract())
1808          Collect(BaseDecl, Methods);
1809      }
1810    }
1811
1812    // Next, zero out any pure virtual methods that this class overrides.
1813    typedef llvm::SmallPtrSet<const CXXMethodDecl*, 4> MethodSetTy;
1814
1815    MethodSetTy OverriddenMethods;
1816    size_t MethodsSize = Methods.size();
1817
1818    for (RecordDecl::decl_iterator i = RD->decls_begin(), e = RD->decls_end();
1819         i != e; ++i) {
1820      // Traverse the record, looking for methods.
1821      if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(*i)) {
1822        // If the method is pure virtual, add it to the methods vector.
1823        if (MD->isPure())
1824          Methods.push_back(MD);
1825
1826        // Record all the overridden methods in our set.
1827        for (CXXMethodDecl::method_iterator I = MD->begin_overridden_methods(),
1828             E = MD->end_overridden_methods(); I != E; ++I) {
1829          // Keep track of the overridden methods.
1830          OverriddenMethods.insert(*I);
1831        }
1832      }
1833    }
1834
1835    // Now go through the methods and zero out all the ones we know are
1836    // overridden.
1837    for (size_t i = 0, e = MethodsSize; i != e; ++i) {
1838      if (OverriddenMethods.count(Methods[i]))
1839        Methods[i] = 0;
1840    }
1841
1842  }
1843}
1844
1845
1846bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
1847                                  unsigned DiagID, AbstractDiagSelID SelID,
1848                                  const CXXRecordDecl *CurrentRD) {
1849  if (SelID == -1)
1850    return RequireNonAbstractType(Loc, T,
1851                                  PDiag(DiagID), CurrentRD);
1852  else
1853    return RequireNonAbstractType(Loc, T,
1854                                  PDiag(DiagID) << SelID, CurrentRD);
1855}
1856
1857bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
1858                                  const PartialDiagnostic &PD,
1859                                  const CXXRecordDecl *CurrentRD) {
1860  if (!getLangOptions().CPlusPlus)
1861    return false;
1862
1863  if (const ArrayType *AT = Context.getAsArrayType(T))
1864    return RequireNonAbstractType(Loc, AT->getElementType(), PD,
1865                                  CurrentRD);
1866
1867  if (const PointerType *PT = T->getAs<PointerType>()) {
1868    // Find the innermost pointer type.
1869    while (const PointerType *T = PT->getPointeeType()->getAs<PointerType>())
1870      PT = T;
1871
1872    if (const ArrayType *AT = Context.getAsArrayType(PT->getPointeeType()))
1873      return RequireNonAbstractType(Loc, AT->getElementType(), PD, CurrentRD);
1874  }
1875
1876  const RecordType *RT = T->getAs<RecordType>();
1877  if (!RT)
1878    return false;
1879
1880  const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl());
1881  if (!RD)
1882    return false;
1883
1884  if (CurrentRD && CurrentRD != RD)
1885    return false;
1886
1887  if (!RD->isAbstract())
1888    return false;
1889
1890  Diag(Loc, PD) << RD->getDeclName();
1891
1892  // Check if we've already emitted the list of pure virtual functions for this
1893  // class.
1894  if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
1895    return true;
1896
1897  PureVirtualMethodCollector Collector(Context, RD);
1898
1899  for (PureVirtualMethodCollector::MethodList::const_iterator I =
1900       Collector.methods_begin(), E = Collector.methods_end(); I != E; ++I) {
1901    const CXXMethodDecl *MD = *I;
1902
1903    Diag(MD->getLocation(), diag::note_pure_virtual_function) <<
1904      MD->getDeclName();
1905  }
1906
1907  if (!PureVirtualClassDiagSet)
1908    PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
1909  PureVirtualClassDiagSet->insert(RD);
1910
1911  return true;
1912}
1913
1914namespace {
1915  class AbstractClassUsageDiagnoser
1916    : public DeclVisitor<AbstractClassUsageDiagnoser, bool> {
1917    Sema &SemaRef;
1918    CXXRecordDecl *AbstractClass;
1919
1920    bool VisitDeclContext(const DeclContext *DC) {
1921      bool Invalid = false;
1922
1923      for (CXXRecordDecl::decl_iterator I = DC->decls_begin(),
1924           E = DC->decls_end(); I != E; ++I)
1925        Invalid |= Visit(*I);
1926
1927      return Invalid;
1928    }
1929
1930  public:
1931    AbstractClassUsageDiagnoser(Sema& SemaRef, CXXRecordDecl *ac)
1932      : SemaRef(SemaRef), AbstractClass(ac) {
1933        Visit(SemaRef.Context.getTranslationUnitDecl());
1934    }
1935
1936    bool VisitFunctionDecl(const FunctionDecl *FD) {
1937      if (FD->isThisDeclarationADefinition()) {
1938        // No need to do the check if we're in a definition, because it requires
1939        // that the return/param types are complete.
1940        // because that requires
1941        return VisitDeclContext(FD);
1942      }
1943
1944      // Check the return type.
1945      QualType RTy = FD->getType()->getAs<FunctionType>()->getResultType();
1946      bool Invalid =
1947        SemaRef.RequireNonAbstractType(FD->getLocation(), RTy,
1948                                       diag::err_abstract_type_in_decl,
1949                                       Sema::AbstractReturnType,
1950                                       AbstractClass);
1951
1952      for (FunctionDecl::param_const_iterator I = FD->param_begin(),
1953           E = FD->param_end(); I != E; ++I) {
1954        const ParmVarDecl *VD = *I;
1955        Invalid |=
1956          SemaRef.RequireNonAbstractType(VD->getLocation(),
1957                                         VD->getOriginalType(),
1958                                         diag::err_abstract_type_in_decl,
1959                                         Sema::AbstractParamType,
1960                                         AbstractClass);
1961      }
1962
1963      return Invalid;
1964    }
1965
1966    bool VisitDecl(const Decl* D) {
1967      if (const DeclContext *DC = dyn_cast<DeclContext>(D))
1968        return VisitDeclContext(DC);
1969
1970      return false;
1971    }
1972  };
1973}
1974
1975/// \brief Perform semantic checks on a class definition that has been
1976/// completing, introducing implicitly-declared members, checking for
1977/// abstract types, etc.
1978void Sema::CheckCompletedCXXClass(CXXRecordDecl *Record) {
1979  if (!Record || Record->isInvalidDecl())
1980    return;
1981
1982  if (!Record->isAbstract()) {
1983    // Collect all the pure virtual methods and see if this is an abstract
1984    // class after all.
1985    PureVirtualMethodCollector Collector(Context, Record);
1986    if (!Collector.empty())
1987      Record->setAbstract(true);
1988  }
1989
1990  if (Record->isAbstract())
1991    (void)AbstractClassUsageDiagnoser(*this, Record);
1992
1993  if (!Record->isDependentType() && !Record->isInvalidDecl())
1994    AddImplicitlyDeclaredMembersToClass(Record);
1995}
1996
1997void Sema::ActOnFinishCXXMemberSpecification(Scope* S, SourceLocation RLoc,
1998                                             DeclPtrTy TagDecl,
1999                                             SourceLocation LBrac,
2000                                             SourceLocation RBrac) {
2001  if (!TagDecl)
2002    return;
2003
2004  AdjustDeclIfTemplate(TagDecl);
2005
2006  ActOnFields(S, RLoc, TagDecl,
2007              (DeclPtrTy*)FieldCollector->getCurFields(),
2008              FieldCollector->getCurNumFields(), LBrac, RBrac, 0);
2009
2010  CheckCompletedCXXClass(
2011                      dyn_cast_or_null<CXXRecordDecl>(TagDecl.getAs<Decl>()));
2012}
2013
2014/// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared
2015/// special functions, such as the default constructor, copy
2016/// constructor, or destructor, to the given C++ class (C++
2017/// [special]p1).  This routine can only be executed just before the
2018/// definition of the class is complete.
2019void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) {
2020  CanQualType ClassType
2021    = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
2022
2023  // FIXME: Implicit declarations have exception specifications, which are
2024  // the union of the specifications of the implicitly called functions.
2025
2026  if (!ClassDecl->hasUserDeclaredConstructor()) {
2027    // C++ [class.ctor]p5:
2028    //   A default constructor for a class X is a constructor of class X
2029    //   that can be called without an argument. If there is no
2030    //   user-declared constructor for class X, a default constructor is
2031    //   implicitly declared. An implicitly-declared default constructor
2032    //   is an inline public member of its class.
2033    DeclarationName Name
2034      = Context.DeclarationNames.getCXXConstructorName(ClassType);
2035    CXXConstructorDecl *DefaultCon =
2036      CXXConstructorDecl::Create(Context, ClassDecl,
2037                                 ClassDecl->getLocation(), Name,
2038                                 Context.getFunctionType(Context.VoidTy,
2039                                                         0, 0, false, 0),
2040                                 /*TInfo=*/0,
2041                                 /*isExplicit=*/false,
2042                                 /*isInline=*/true,
2043                                 /*isImplicitlyDeclared=*/true);
2044    DefaultCon->setAccess(AS_public);
2045    DefaultCon->setImplicit();
2046    DefaultCon->setTrivial(ClassDecl->hasTrivialConstructor());
2047    ClassDecl->addDecl(DefaultCon);
2048  }
2049
2050  if (!ClassDecl->hasUserDeclaredCopyConstructor()) {
2051    // C++ [class.copy]p4:
2052    //   If the class definition does not explicitly declare a copy
2053    //   constructor, one is declared implicitly.
2054
2055    // C++ [class.copy]p5:
2056    //   The implicitly-declared copy constructor for a class X will
2057    //   have the form
2058    //
2059    //       X::X(const X&)
2060    //
2061    //   if
2062    bool HasConstCopyConstructor = true;
2063
2064    //     -- each direct or virtual base class B of X has a copy
2065    //        constructor whose first parameter is of type const B& or
2066    //        const volatile B&, and
2067    for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin();
2068         HasConstCopyConstructor && Base != ClassDecl->bases_end(); ++Base) {
2069      const CXXRecordDecl *BaseClassDecl
2070        = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
2071      HasConstCopyConstructor
2072        = BaseClassDecl->hasConstCopyConstructor(Context);
2073    }
2074
2075    //     -- for all the nonstatic data members of X that are of a
2076    //        class type M (or array thereof), each such class type
2077    //        has a copy constructor whose first parameter is of type
2078    //        const M& or const volatile M&.
2079    for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin();
2080         HasConstCopyConstructor && Field != ClassDecl->field_end();
2081         ++Field) {
2082      QualType FieldType = (*Field)->getType();
2083      if (const ArrayType *Array = Context.getAsArrayType(FieldType))
2084        FieldType = Array->getElementType();
2085      if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) {
2086        const CXXRecordDecl *FieldClassDecl
2087          = cast<CXXRecordDecl>(FieldClassType->getDecl());
2088        HasConstCopyConstructor
2089          = FieldClassDecl->hasConstCopyConstructor(Context);
2090      }
2091    }
2092
2093    //   Otherwise, the implicitly declared copy constructor will have
2094    //   the form
2095    //
2096    //       X::X(X&)
2097    QualType ArgType = ClassType;
2098    if (HasConstCopyConstructor)
2099      ArgType = ArgType.withConst();
2100    ArgType = Context.getLValueReferenceType(ArgType);
2101
2102    //   An implicitly-declared copy constructor is an inline public
2103    //   member of its class.
2104    DeclarationName Name
2105      = Context.DeclarationNames.getCXXConstructorName(ClassType);
2106    CXXConstructorDecl *CopyConstructor
2107      = CXXConstructorDecl::Create(Context, ClassDecl,
2108                                   ClassDecl->getLocation(), Name,
2109                                   Context.getFunctionType(Context.VoidTy,
2110                                                           &ArgType, 1,
2111                                                           false, 0),
2112                                   /*TInfo=*/0,
2113                                   /*isExplicit=*/false,
2114                                   /*isInline=*/true,
2115                                   /*isImplicitlyDeclared=*/true);
2116    CopyConstructor->setAccess(AS_public);
2117    CopyConstructor->setImplicit();
2118    CopyConstructor->setTrivial(ClassDecl->hasTrivialCopyConstructor());
2119
2120    // Add the parameter to the constructor.
2121    ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyConstructor,
2122                                                 ClassDecl->getLocation(),
2123                                                 /*IdentifierInfo=*/0,
2124                                                 ArgType, /*TInfo=*/0,
2125                                                 VarDecl::None, 0);
2126    CopyConstructor->setParams(Context, &FromParam, 1);
2127    ClassDecl->addDecl(CopyConstructor);
2128  }
2129
2130  if (!ClassDecl->hasUserDeclaredCopyAssignment()) {
2131    // Note: The following rules are largely analoguous to the copy
2132    // constructor rules. Note that virtual bases are not taken into account
2133    // for determining the argument type of the operator. Note also that
2134    // operators taking an object instead of a reference are allowed.
2135    //
2136    // C++ [class.copy]p10:
2137    //   If the class definition does not explicitly declare a copy
2138    //   assignment operator, one is declared implicitly.
2139    //   The implicitly-defined copy assignment operator for a class X
2140    //   will have the form
2141    //
2142    //       X& X::operator=(const X&)
2143    //
2144    //   if
2145    bool HasConstCopyAssignment = true;
2146
2147    //       -- each direct base class B of X has a copy assignment operator
2148    //          whose parameter is of type const B&, const volatile B& or B,
2149    //          and
2150    for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin();
2151         HasConstCopyAssignment && Base != ClassDecl->bases_end(); ++Base) {
2152      assert(!Base->getType()->isDependentType() &&
2153            "Cannot generate implicit members for class with dependent bases.");
2154      const CXXRecordDecl *BaseClassDecl
2155        = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
2156      const CXXMethodDecl *MD = 0;
2157      HasConstCopyAssignment = BaseClassDecl->hasConstCopyAssignment(Context,
2158                                                                     MD);
2159    }
2160
2161    //       -- for all the nonstatic data members of X that are of a class
2162    //          type M (or array thereof), each such class type has a copy
2163    //          assignment operator whose parameter is of type const M&,
2164    //          const volatile M& or M.
2165    for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin();
2166         HasConstCopyAssignment && Field != ClassDecl->field_end();
2167         ++Field) {
2168      QualType FieldType = (*Field)->getType();
2169      if (const ArrayType *Array = Context.getAsArrayType(FieldType))
2170        FieldType = Array->getElementType();
2171      if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) {
2172        const CXXRecordDecl *FieldClassDecl
2173          = cast<CXXRecordDecl>(FieldClassType->getDecl());
2174        const CXXMethodDecl *MD = 0;
2175        HasConstCopyAssignment
2176          = FieldClassDecl->hasConstCopyAssignment(Context, MD);
2177      }
2178    }
2179
2180    //   Otherwise, the implicitly declared copy assignment operator will
2181    //   have the form
2182    //
2183    //       X& X::operator=(X&)
2184    QualType ArgType = ClassType;
2185    QualType RetType = Context.getLValueReferenceType(ArgType);
2186    if (HasConstCopyAssignment)
2187      ArgType = ArgType.withConst();
2188    ArgType = Context.getLValueReferenceType(ArgType);
2189
2190    //   An implicitly-declared copy assignment operator is an inline public
2191    //   member of its class.
2192    DeclarationName Name =
2193      Context.DeclarationNames.getCXXOperatorName(OO_Equal);
2194    CXXMethodDecl *CopyAssignment =
2195      CXXMethodDecl::Create(Context, ClassDecl, ClassDecl->getLocation(), Name,
2196                            Context.getFunctionType(RetType, &ArgType, 1,
2197                                                    false, 0),
2198                            /*TInfo=*/0, /*isStatic=*/false, /*isInline=*/true);
2199    CopyAssignment->setAccess(AS_public);
2200    CopyAssignment->setImplicit();
2201    CopyAssignment->setTrivial(ClassDecl->hasTrivialCopyAssignment());
2202    CopyAssignment->setCopyAssignment(true);
2203
2204    // Add the parameter to the operator.
2205    ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment,
2206                                                 ClassDecl->getLocation(),
2207                                                 /*IdentifierInfo=*/0,
2208                                                 ArgType, /*TInfo=*/0,
2209                                                 VarDecl::None, 0);
2210    CopyAssignment->setParams(Context, &FromParam, 1);
2211
2212    // Don't call addedAssignmentOperator. There is no way to distinguish an
2213    // implicit from an explicit assignment operator.
2214    ClassDecl->addDecl(CopyAssignment);
2215    AddOverriddenMethods(ClassDecl, CopyAssignment);
2216  }
2217
2218  if (!ClassDecl->hasUserDeclaredDestructor()) {
2219    // C++ [class.dtor]p2:
2220    //   If a class has no user-declared destructor, a destructor is
2221    //   declared implicitly. An implicitly-declared destructor is an
2222    //   inline public member of its class.
2223    DeclarationName Name
2224      = Context.DeclarationNames.getCXXDestructorName(ClassType);
2225    CXXDestructorDecl *Destructor
2226      = CXXDestructorDecl::Create(Context, ClassDecl,
2227                                  ClassDecl->getLocation(), Name,
2228                                  Context.getFunctionType(Context.VoidTy,
2229                                                          0, 0, false, 0),
2230                                  /*isInline=*/true,
2231                                  /*isImplicitlyDeclared=*/true);
2232    Destructor->setAccess(AS_public);
2233    Destructor->setImplicit();
2234    Destructor->setTrivial(ClassDecl->hasTrivialDestructor());
2235    ClassDecl->addDecl(Destructor);
2236
2237    AddOverriddenMethods(ClassDecl, Destructor);
2238  }
2239}
2240
2241void Sema::ActOnReenterTemplateScope(Scope *S, DeclPtrTy TemplateD) {
2242  Decl *D = TemplateD.getAs<Decl>();
2243  if (!D)
2244    return;
2245
2246  TemplateParameterList *Params = 0;
2247  if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D))
2248    Params = Template->getTemplateParameters();
2249  else if (ClassTemplatePartialSpecializationDecl *PartialSpec
2250           = dyn_cast<ClassTemplatePartialSpecializationDecl>(D))
2251    Params = PartialSpec->getTemplateParameters();
2252  else
2253    return;
2254
2255  for (TemplateParameterList::iterator Param = Params->begin(),
2256                                    ParamEnd = Params->end();
2257       Param != ParamEnd; ++Param) {
2258    NamedDecl *Named = cast<NamedDecl>(*Param);
2259    if (Named->getDeclName()) {
2260      S->AddDecl(DeclPtrTy::make(Named));
2261      IdResolver.AddDecl(Named);
2262    }
2263  }
2264}
2265
2266/// ActOnStartDelayedCXXMethodDeclaration - We have completed
2267/// parsing a top-level (non-nested) C++ class, and we are now
2268/// parsing those parts of the given Method declaration that could
2269/// not be parsed earlier (C++ [class.mem]p2), such as default
2270/// arguments. This action should enter the scope of the given
2271/// Method declaration as if we had just parsed the qualified method
2272/// name. However, it should not bring the parameters into scope;
2273/// that will be performed by ActOnDelayedCXXMethodParameter.
2274void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, DeclPtrTy MethodD) {
2275  if (!MethodD)
2276    return;
2277
2278  AdjustDeclIfTemplate(MethodD);
2279
2280  CXXScopeSpec SS;
2281  FunctionDecl *Method = cast<FunctionDecl>(MethodD.getAs<Decl>());
2282  QualType ClassTy
2283    = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
2284  SS.setScopeRep(
2285    NestedNameSpecifier::Create(Context, 0, false, ClassTy.getTypePtr()));
2286  ActOnCXXEnterDeclaratorScope(S, SS);
2287}
2288
2289/// ActOnDelayedCXXMethodParameter - We've already started a delayed
2290/// C++ method declaration. We're (re-)introducing the given
2291/// function parameter into scope for use in parsing later parts of
2292/// the method declaration. For example, we could see an
2293/// ActOnParamDefaultArgument event for this parameter.
2294void Sema::ActOnDelayedCXXMethodParameter(Scope *S, DeclPtrTy ParamD) {
2295  if (!ParamD)
2296    return;
2297
2298  ParmVarDecl *Param = cast<ParmVarDecl>(ParamD.getAs<Decl>());
2299
2300  // If this parameter has an unparsed default argument, clear it out
2301  // to make way for the parsed default argument.
2302  if (Param->hasUnparsedDefaultArg())
2303    Param->setDefaultArg(0);
2304
2305  S->AddDecl(DeclPtrTy::make(Param));
2306  if (Param->getDeclName())
2307    IdResolver.AddDecl(Param);
2308}
2309
2310/// ActOnFinishDelayedCXXMethodDeclaration - We have finished
2311/// processing the delayed method declaration for Method. The method
2312/// declaration is now considered finished. There may be a separate
2313/// ActOnStartOfFunctionDef action later (not necessarily
2314/// immediately!) for this method, if it was also defined inside the
2315/// class body.
2316void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, DeclPtrTy MethodD) {
2317  if (!MethodD)
2318    return;
2319
2320  AdjustDeclIfTemplate(MethodD);
2321
2322  FunctionDecl *Method = cast<FunctionDecl>(MethodD.getAs<Decl>());
2323  CXXScopeSpec SS;
2324  QualType ClassTy
2325    = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
2326  SS.setScopeRep(
2327    NestedNameSpecifier::Create(Context, 0, false, ClassTy.getTypePtr()));
2328  ActOnCXXExitDeclaratorScope(S, SS);
2329
2330  // Now that we have our default arguments, check the constructor
2331  // again. It could produce additional diagnostics or affect whether
2332  // the class has implicitly-declared destructors, among other
2333  // things.
2334  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method))
2335    CheckConstructor(Constructor);
2336
2337  // Check the default arguments, which we may have added.
2338  if (!Method->isInvalidDecl())
2339    CheckCXXDefaultArguments(Method);
2340}
2341
2342/// CheckConstructorDeclarator - Called by ActOnDeclarator to check
2343/// the well-formedness of the constructor declarator @p D with type @p
2344/// R. If there are any errors in the declarator, this routine will
2345/// emit diagnostics and set the invalid bit to true.  In any case, the type
2346/// will be updated to reflect a well-formed type for the constructor and
2347/// returned.
2348QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R,
2349                                          FunctionDecl::StorageClass &SC) {
2350  bool isVirtual = D.getDeclSpec().isVirtualSpecified();
2351
2352  // C++ [class.ctor]p3:
2353  //   A constructor shall not be virtual (10.3) or static (9.4). A
2354  //   constructor can be invoked for a const, volatile or const
2355  //   volatile object. A constructor shall not be declared const,
2356  //   volatile, or const volatile (9.3.2).
2357  if (isVirtual) {
2358    if (!D.isInvalidType())
2359      Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
2360        << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc())
2361        << SourceRange(D.getIdentifierLoc());
2362    D.setInvalidType();
2363  }
2364  if (SC == FunctionDecl::Static) {
2365    if (!D.isInvalidType())
2366      Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
2367        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
2368        << SourceRange(D.getIdentifierLoc());
2369    D.setInvalidType();
2370    SC = FunctionDecl::None;
2371  }
2372
2373  DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
2374  if (FTI.TypeQuals != 0) {
2375    if (FTI.TypeQuals & Qualifiers::Const)
2376      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
2377        << "const" << SourceRange(D.getIdentifierLoc());
2378    if (FTI.TypeQuals & Qualifiers::Volatile)
2379      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
2380        << "volatile" << SourceRange(D.getIdentifierLoc());
2381    if (FTI.TypeQuals & Qualifiers::Restrict)
2382      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
2383        << "restrict" << SourceRange(D.getIdentifierLoc());
2384  }
2385
2386  // Rebuild the function type "R" without any type qualifiers (in
2387  // case any of the errors above fired) and with "void" as the
2388  // return type, since constructors don't have return types. We
2389  // *always* have to do this, because GetTypeForDeclarator will
2390  // put in a result type of "int" when none was specified.
2391  const FunctionProtoType *Proto = R->getAs<FunctionProtoType>();
2392  return Context.getFunctionType(Context.VoidTy, Proto->arg_type_begin(),
2393                                 Proto->getNumArgs(),
2394                                 Proto->isVariadic(), 0);
2395}
2396
2397/// CheckConstructor - Checks a fully-formed constructor for
2398/// well-formedness, issuing any diagnostics required. Returns true if
2399/// the constructor declarator is invalid.
2400void Sema::CheckConstructor(CXXConstructorDecl *Constructor) {
2401  CXXRecordDecl *ClassDecl
2402    = dyn_cast<CXXRecordDecl>(Constructor->getDeclContext());
2403  if (!ClassDecl)
2404    return Constructor->setInvalidDecl();
2405
2406  // C++ [class.copy]p3:
2407  //   A declaration of a constructor for a class X is ill-formed if
2408  //   its first parameter is of type (optionally cv-qualified) X and
2409  //   either there are no other parameters or else all other
2410  //   parameters have default arguments.
2411  if (!Constructor->isInvalidDecl() &&
2412      ((Constructor->getNumParams() == 1) ||
2413       (Constructor->getNumParams() > 1 &&
2414        Constructor->getParamDecl(1)->hasDefaultArg())) &&
2415      Constructor->getTemplateSpecializationKind()
2416                                              != TSK_ImplicitInstantiation) {
2417    QualType ParamType = Constructor->getParamDecl(0)->getType();
2418    QualType ClassTy = Context.getTagDeclType(ClassDecl);
2419    if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) {
2420      SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation();
2421      Diag(ParamLoc, diag::err_constructor_byvalue_arg)
2422        << CodeModificationHint::CreateInsertion(ParamLoc, " const &");
2423
2424      // FIXME: Rather that making the constructor invalid, we should endeavor
2425      // to fix the type.
2426      Constructor->setInvalidDecl();
2427    }
2428  }
2429
2430  // Notify the class that we've added a constructor.
2431  ClassDecl->addedConstructor(Context, Constructor);
2432}
2433
2434/// CheckDestructor - Checks a fully-formed destructor for well-formedness,
2435/// issuing any diagnostics required. Returns true on error.
2436bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) {
2437  CXXRecordDecl *RD = Destructor->getParent();
2438
2439  if (Destructor->isVirtual()) {
2440    SourceLocation Loc;
2441
2442    if (!Destructor->isImplicit())
2443      Loc = Destructor->getLocation();
2444    else
2445      Loc = RD->getLocation();
2446
2447    // If we have a virtual destructor, look up the deallocation function
2448    FunctionDecl *OperatorDelete = 0;
2449    DeclarationName Name =
2450    Context.DeclarationNames.getCXXOperatorName(OO_Delete);
2451    if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete))
2452      return true;
2453
2454    Destructor->setOperatorDelete(OperatorDelete);
2455  }
2456
2457  return false;
2458}
2459
2460static inline bool
2461FTIHasSingleVoidArgument(DeclaratorChunk::FunctionTypeInfo &FTI) {
2462  return (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 &&
2463          FTI.ArgInfo[0].Param &&
2464          FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType()->isVoidType());
2465}
2466
2467/// CheckDestructorDeclarator - Called by ActOnDeclarator to check
2468/// the well-formednes of the destructor declarator @p D with type @p
2469/// R. If there are any errors in the declarator, this routine will
2470/// emit diagnostics and set the declarator to invalid.  Even if this happens,
2471/// will be updated to reflect a well-formed type for the destructor and
2472/// returned.
2473QualType Sema::CheckDestructorDeclarator(Declarator &D,
2474                                         FunctionDecl::StorageClass& SC) {
2475  // C++ [class.dtor]p1:
2476  //   [...] A typedef-name that names a class is a class-name
2477  //   (7.1.3); however, a typedef-name that names a class shall not
2478  //   be used as the identifier in the declarator for a destructor
2479  //   declaration.
2480  QualType DeclaratorType = GetTypeFromParser(D.getName().DestructorName);
2481  if (isa<TypedefType>(DeclaratorType)) {
2482    Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name)
2483      << DeclaratorType;
2484    D.setInvalidType();
2485  }
2486
2487  // C++ [class.dtor]p2:
2488  //   A destructor is used to destroy objects of its class type. A
2489  //   destructor takes no parameters, and no return type can be
2490  //   specified for it (not even void). The address of a destructor
2491  //   shall not be taken. A destructor shall not be static. A
2492  //   destructor can be invoked for a const, volatile or const
2493  //   volatile object. A destructor shall not be declared const,
2494  //   volatile or const volatile (9.3.2).
2495  if (SC == FunctionDecl::Static) {
2496    if (!D.isInvalidType())
2497      Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be)
2498        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
2499        << SourceRange(D.getIdentifierLoc());
2500    SC = FunctionDecl::None;
2501    D.setInvalidType();
2502  }
2503  if (D.getDeclSpec().hasTypeSpecifier() && !D.isInvalidType()) {
2504    // Destructors don't have return types, but the parser will
2505    // happily parse something like:
2506    //
2507    //   class X {
2508    //     float ~X();
2509    //   };
2510    //
2511    // The return type will be eliminated later.
2512    Diag(D.getIdentifierLoc(), diag::err_destructor_return_type)
2513      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
2514      << SourceRange(D.getIdentifierLoc());
2515  }
2516
2517  DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
2518  if (FTI.TypeQuals != 0 && !D.isInvalidType()) {
2519    if (FTI.TypeQuals & Qualifiers::Const)
2520      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
2521        << "const" << SourceRange(D.getIdentifierLoc());
2522    if (FTI.TypeQuals & Qualifiers::Volatile)
2523      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
2524        << "volatile" << SourceRange(D.getIdentifierLoc());
2525    if (FTI.TypeQuals & Qualifiers::Restrict)
2526      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
2527        << "restrict" << SourceRange(D.getIdentifierLoc());
2528    D.setInvalidType();
2529  }
2530
2531  // Make sure we don't have any parameters.
2532  if (FTI.NumArgs > 0 && !FTIHasSingleVoidArgument(FTI)) {
2533    Diag(D.getIdentifierLoc(), diag::err_destructor_with_params);
2534
2535    // Delete the parameters.
2536    FTI.freeArgs();
2537    D.setInvalidType();
2538  }
2539
2540  // Make sure the destructor isn't variadic.
2541  if (FTI.isVariadic) {
2542    Diag(D.getIdentifierLoc(), diag::err_destructor_variadic);
2543    D.setInvalidType();
2544  }
2545
2546  // Rebuild the function type "R" without any type qualifiers or
2547  // parameters (in case any of the errors above fired) and with
2548  // "void" as the return type, since destructors don't have return
2549  // types. We *always* have to do this, because GetTypeForDeclarator
2550  // will put in a result type of "int" when none was specified.
2551  return Context.getFunctionType(Context.VoidTy, 0, 0, false, 0);
2552}
2553
2554/// CheckConversionDeclarator - Called by ActOnDeclarator to check the
2555/// well-formednes of the conversion function declarator @p D with
2556/// type @p R. If there are any errors in the declarator, this routine
2557/// will emit diagnostics and return true. Otherwise, it will return
2558/// false. Either way, the type @p R will be updated to reflect a
2559/// well-formed type for the conversion operator.
2560void Sema::CheckConversionDeclarator(Declarator &D, QualType &R,
2561                                     FunctionDecl::StorageClass& SC) {
2562  // C++ [class.conv.fct]p1:
2563  //   Neither parameter types nor return type can be specified. The
2564  //   type of a conversion function (8.3.5) is "function taking no
2565  //   parameter returning conversion-type-id."
2566  if (SC == FunctionDecl::Static) {
2567    if (!D.isInvalidType())
2568      Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member)
2569        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
2570        << SourceRange(D.getIdentifierLoc());
2571    D.setInvalidType();
2572    SC = FunctionDecl::None;
2573  }
2574  if (D.getDeclSpec().hasTypeSpecifier() && !D.isInvalidType()) {
2575    // Conversion functions don't have return types, but the parser will
2576    // happily parse something like:
2577    //
2578    //   class X {
2579    //     float operator bool();
2580    //   };
2581    //
2582    // The return type will be changed later anyway.
2583    Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type)
2584      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
2585      << SourceRange(D.getIdentifierLoc());
2586  }
2587
2588  // Make sure we don't have any parameters.
2589  if (R->getAs<FunctionProtoType>()->getNumArgs() > 0) {
2590    Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params);
2591
2592    // Delete the parameters.
2593    D.getTypeObject(0).Fun.freeArgs();
2594    D.setInvalidType();
2595  }
2596
2597  // Make sure the conversion function isn't variadic.
2598  if (R->getAs<FunctionProtoType>()->isVariadic() && !D.isInvalidType()) {
2599    Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic);
2600    D.setInvalidType();
2601  }
2602
2603  // C++ [class.conv.fct]p4:
2604  //   The conversion-type-id shall not represent a function type nor
2605  //   an array type.
2606  QualType ConvType = GetTypeFromParser(D.getName().ConversionFunctionId);
2607  if (ConvType->isArrayType()) {
2608    Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array);
2609    ConvType = Context.getPointerType(ConvType);
2610    D.setInvalidType();
2611  } else if (ConvType->isFunctionType()) {
2612    Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function);
2613    ConvType = Context.getPointerType(ConvType);
2614    D.setInvalidType();
2615  }
2616
2617  // Rebuild the function type "R" without any parameters (in case any
2618  // of the errors above fired) and with the conversion type as the
2619  // return type.
2620  R = Context.getFunctionType(ConvType, 0, 0, false,
2621                              R->getAs<FunctionProtoType>()->getTypeQuals());
2622
2623  // C++0x explicit conversion operators.
2624  if (D.getDeclSpec().isExplicitSpecified() && !getLangOptions().CPlusPlus0x)
2625    Diag(D.getDeclSpec().getExplicitSpecLoc(),
2626         diag::warn_explicit_conversion_functions)
2627      << SourceRange(D.getDeclSpec().getExplicitSpecLoc());
2628}
2629
2630/// ActOnConversionDeclarator - Called by ActOnDeclarator to complete
2631/// the declaration of the given C++ conversion function. This routine
2632/// is responsible for recording the conversion function in the C++
2633/// class, if possible.
2634Sema::DeclPtrTy Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) {
2635  assert(Conversion && "Expected to receive a conversion function declaration");
2636
2637  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext());
2638
2639  // Make sure we aren't redeclaring the conversion function.
2640  QualType ConvType = Context.getCanonicalType(Conversion->getConversionType());
2641
2642  // C++ [class.conv.fct]p1:
2643  //   [...] A conversion function is never used to convert a
2644  //   (possibly cv-qualified) object to the (possibly cv-qualified)
2645  //   same object type (or a reference to it), to a (possibly
2646  //   cv-qualified) base class of that type (or a reference to it),
2647  //   or to (possibly cv-qualified) void.
2648  // FIXME: Suppress this warning if the conversion function ends up being a
2649  // virtual function that overrides a virtual function in a base class.
2650  QualType ClassType
2651    = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
2652  if (const ReferenceType *ConvTypeRef = ConvType->getAs<ReferenceType>())
2653    ConvType = ConvTypeRef->getPointeeType();
2654  if (ConvType->isRecordType()) {
2655    ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType();
2656    if (ConvType == ClassType)
2657      Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used)
2658        << ClassType;
2659    else if (IsDerivedFrom(ClassType, ConvType))
2660      Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used)
2661        <<  ClassType << ConvType;
2662  } else if (ConvType->isVoidType()) {
2663    Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used)
2664      << ClassType << ConvType;
2665  }
2666
2667  if (Conversion->getPreviousDeclaration()) {
2668    const NamedDecl *ExpectedPrevDecl = Conversion->getPreviousDeclaration();
2669    if (FunctionTemplateDecl *ConversionTemplate
2670          = Conversion->getDescribedFunctionTemplate())
2671      ExpectedPrevDecl = ConversionTemplate->getPreviousDeclaration();
2672    if (ClassDecl->replaceConversion(ExpectedPrevDecl, Conversion))
2673      return DeclPtrTy::make(Conversion);
2674    assert(Conversion->isInvalidDecl() && "Conversion should not get here.");
2675  } else if (FunctionTemplateDecl *ConversionTemplate
2676               = Conversion->getDescribedFunctionTemplate())
2677    ClassDecl->addConversionFunction(ConversionTemplate);
2678  else if (!Conversion->getPrimaryTemplate()) // ignore specializations
2679    ClassDecl->addConversionFunction(Conversion);
2680
2681  return DeclPtrTy::make(Conversion);
2682}
2683
2684//===----------------------------------------------------------------------===//
2685// Namespace Handling
2686//===----------------------------------------------------------------------===//
2687
2688/// ActOnStartNamespaceDef - This is called at the start of a namespace
2689/// definition.
2690Sema::DeclPtrTy Sema::ActOnStartNamespaceDef(Scope *NamespcScope,
2691                                             SourceLocation IdentLoc,
2692                                             IdentifierInfo *II,
2693                                             SourceLocation LBrace) {
2694  NamespaceDecl *Namespc =
2695      NamespaceDecl::Create(Context, CurContext, IdentLoc, II);
2696  Namespc->setLBracLoc(LBrace);
2697
2698  Scope *DeclRegionScope = NamespcScope->getParent();
2699
2700  if (II) {
2701    // C++ [namespace.def]p2:
2702    // The identifier in an original-namespace-definition shall not have been
2703    // previously defined in the declarative region in which the
2704    // original-namespace-definition appears. The identifier in an
2705    // original-namespace-definition is the name of the namespace. Subsequently
2706    // in that declarative region, it is treated as an original-namespace-name.
2707
2708    NamedDecl *PrevDecl
2709      = LookupSingleName(DeclRegionScope, II, LookupOrdinaryName,
2710                         ForRedeclaration);
2711
2712    if (NamespaceDecl *OrigNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl)) {
2713      // This is an extended namespace definition.
2714      // Attach this namespace decl to the chain of extended namespace
2715      // definitions.
2716      OrigNS->setNextNamespace(Namespc);
2717      Namespc->setOriginalNamespace(OrigNS->getOriginalNamespace());
2718
2719      // Remove the previous declaration from the scope.
2720      if (DeclRegionScope->isDeclScope(DeclPtrTy::make(OrigNS))) {
2721        IdResolver.RemoveDecl(OrigNS);
2722        DeclRegionScope->RemoveDecl(DeclPtrTy::make(OrigNS));
2723      }
2724    } else if (PrevDecl) {
2725      // This is an invalid name redefinition.
2726      Diag(Namespc->getLocation(), diag::err_redefinition_different_kind)
2727       << Namespc->getDeclName();
2728      Diag(PrevDecl->getLocation(), diag::note_previous_definition);
2729      Namespc->setInvalidDecl();
2730      // Continue on to push Namespc as current DeclContext and return it.
2731    } else if (II->isStr("std") &&
2732               CurContext->getLookupContext()->isTranslationUnit()) {
2733      // This is the first "real" definition of the namespace "std", so update
2734      // our cache of the "std" namespace to point at this definition.
2735      if (StdNamespace) {
2736        // We had already defined a dummy namespace "std". Link this new
2737        // namespace definition to the dummy namespace "std".
2738        StdNamespace->setNextNamespace(Namespc);
2739        StdNamespace->setLocation(IdentLoc);
2740        Namespc->setOriginalNamespace(StdNamespace->getOriginalNamespace());
2741      }
2742
2743      // Make our StdNamespace cache point at the first real definition of the
2744      // "std" namespace.
2745      StdNamespace = Namespc;
2746    }
2747
2748    PushOnScopeChains(Namespc, DeclRegionScope);
2749  } else {
2750    // Anonymous namespaces.
2751    assert(Namespc->isAnonymousNamespace());
2752    CurContext->addDecl(Namespc);
2753
2754    // Link the anonymous namespace into its parent.
2755    NamespaceDecl *PrevDecl;
2756    DeclContext *Parent = CurContext->getLookupContext();
2757    if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
2758      PrevDecl = TU->getAnonymousNamespace();
2759      TU->setAnonymousNamespace(Namespc);
2760    } else {
2761      NamespaceDecl *ND = cast<NamespaceDecl>(Parent);
2762      PrevDecl = ND->getAnonymousNamespace();
2763      ND->setAnonymousNamespace(Namespc);
2764    }
2765
2766    // Link the anonymous namespace with its previous declaration.
2767    if (PrevDecl) {
2768      assert(PrevDecl->isAnonymousNamespace());
2769      assert(!PrevDecl->getNextNamespace());
2770      Namespc->setOriginalNamespace(PrevDecl->getOriginalNamespace());
2771      PrevDecl->setNextNamespace(Namespc);
2772    }
2773
2774    // C++ [namespace.unnamed]p1.  An unnamed-namespace-definition
2775    //   behaves as if it were replaced by
2776    //     namespace unique { /* empty body */ }
2777    //     using namespace unique;
2778    //     namespace unique { namespace-body }
2779    //   where all occurrences of 'unique' in a translation unit are
2780    //   replaced by the same identifier and this identifier differs
2781    //   from all other identifiers in the entire program.
2782
2783    // We just create the namespace with an empty name and then add an
2784    // implicit using declaration, just like the standard suggests.
2785    //
2786    // CodeGen enforces the "universally unique" aspect by giving all
2787    // declarations semantically contained within an anonymous
2788    // namespace internal linkage.
2789
2790    if (!PrevDecl) {
2791      UsingDirectiveDecl* UD
2792        = UsingDirectiveDecl::Create(Context, CurContext,
2793                                     /* 'using' */ LBrace,
2794                                     /* 'namespace' */ SourceLocation(),
2795                                     /* qualifier */ SourceRange(),
2796                                     /* NNS */ NULL,
2797                                     /* identifier */ SourceLocation(),
2798                                     Namespc,
2799                                     /* Ancestor */ CurContext);
2800      UD->setImplicit();
2801      CurContext->addDecl(UD);
2802    }
2803  }
2804
2805  // Although we could have an invalid decl (i.e. the namespace name is a
2806  // redefinition), push it as current DeclContext and try to continue parsing.
2807  // FIXME: We should be able to push Namespc here, so that the each DeclContext
2808  // for the namespace has the declarations that showed up in that particular
2809  // namespace definition.
2810  PushDeclContext(NamespcScope, Namespc);
2811  return DeclPtrTy::make(Namespc);
2812}
2813
2814/// getNamespaceDecl - Returns the namespace a decl represents. If the decl
2815/// is a namespace alias, returns the namespace it points to.
2816static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) {
2817  if (NamespaceAliasDecl *AD = dyn_cast_or_null<NamespaceAliasDecl>(D))
2818    return AD->getNamespace();
2819  return dyn_cast_or_null<NamespaceDecl>(D);
2820}
2821
2822/// ActOnFinishNamespaceDef - This callback is called after a namespace is
2823/// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef.
2824void Sema::ActOnFinishNamespaceDef(DeclPtrTy D, SourceLocation RBrace) {
2825  Decl *Dcl = D.getAs<Decl>();
2826  NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl);
2827  assert(Namespc && "Invalid parameter, expected NamespaceDecl");
2828  Namespc->setRBracLoc(RBrace);
2829  PopDeclContext();
2830}
2831
2832Sema::DeclPtrTy Sema::ActOnUsingDirective(Scope *S,
2833                                          SourceLocation UsingLoc,
2834                                          SourceLocation NamespcLoc,
2835                                          const CXXScopeSpec &SS,
2836                                          SourceLocation IdentLoc,
2837                                          IdentifierInfo *NamespcName,
2838                                          AttributeList *AttrList) {
2839  assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
2840  assert(NamespcName && "Invalid NamespcName.");
2841  assert(IdentLoc.isValid() && "Invalid NamespceName location.");
2842  assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
2843
2844  UsingDirectiveDecl *UDir = 0;
2845
2846  // Lookup namespace name.
2847  LookupResult R(*this, NamespcName, IdentLoc, LookupNamespaceName);
2848  LookupParsedName(R, S, &SS);
2849  if (R.isAmbiguous())
2850    return DeclPtrTy();
2851
2852  if (!R.empty()) {
2853    NamedDecl *Named = R.getFoundDecl();
2854    assert((isa<NamespaceDecl>(Named) || isa<NamespaceAliasDecl>(Named))
2855        && "expected namespace decl");
2856    // C++ [namespace.udir]p1:
2857    //   A using-directive specifies that the names in the nominated
2858    //   namespace can be used in the scope in which the
2859    //   using-directive appears after the using-directive. During
2860    //   unqualified name lookup (3.4.1), the names appear as if they
2861    //   were declared in the nearest enclosing namespace which
2862    //   contains both the using-directive and the nominated
2863    //   namespace. [Note: in this context, "contains" means "contains
2864    //   directly or indirectly". ]
2865
2866    // Find enclosing context containing both using-directive and
2867    // nominated namespace.
2868    NamespaceDecl *NS = getNamespaceDecl(Named);
2869    DeclContext *CommonAncestor = cast<DeclContext>(NS);
2870    while (CommonAncestor && !CommonAncestor->Encloses(CurContext))
2871      CommonAncestor = CommonAncestor->getParent();
2872
2873    UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc, NamespcLoc,
2874                                      SS.getRange(),
2875                                      (NestedNameSpecifier *)SS.getScopeRep(),
2876                                      IdentLoc, Named, CommonAncestor);
2877    PushUsingDirective(S, UDir);
2878  } else {
2879    Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
2880  }
2881
2882  // FIXME: We ignore attributes for now.
2883  delete AttrList;
2884  return DeclPtrTy::make(UDir);
2885}
2886
2887void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) {
2888  // If scope has associated entity, then using directive is at namespace
2889  // or translation unit scope. We add UsingDirectiveDecls, into
2890  // it's lookup structure.
2891  if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity()))
2892    Ctx->addDecl(UDir);
2893  else
2894    // Otherwise it is block-sope. using-directives will affect lookup
2895    // only to the end of scope.
2896    S->PushUsingDirective(DeclPtrTy::make(UDir));
2897}
2898
2899
2900Sema::DeclPtrTy Sema::ActOnUsingDeclaration(Scope *S,
2901                                            AccessSpecifier AS,
2902                                            bool HasUsingKeyword,
2903                                            SourceLocation UsingLoc,
2904                                            const CXXScopeSpec &SS,
2905                                            UnqualifiedId &Name,
2906                                            AttributeList *AttrList,
2907                                            bool IsTypeName,
2908                                            SourceLocation TypenameLoc) {
2909  assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
2910
2911  switch (Name.getKind()) {
2912  case UnqualifiedId::IK_Identifier:
2913  case UnqualifiedId::IK_OperatorFunctionId:
2914  case UnqualifiedId::IK_LiteralOperatorId:
2915  case UnqualifiedId::IK_ConversionFunctionId:
2916    break;
2917
2918  case UnqualifiedId::IK_ConstructorName:
2919    // C++0x inherited constructors.
2920    if (getLangOptions().CPlusPlus0x) break;
2921
2922    Diag(Name.getSourceRange().getBegin(), diag::err_using_decl_constructor)
2923      << SS.getRange();
2924    return DeclPtrTy();
2925
2926  case UnqualifiedId::IK_DestructorName:
2927    Diag(Name.getSourceRange().getBegin(), diag::err_using_decl_destructor)
2928      << SS.getRange();
2929    return DeclPtrTy();
2930
2931  case UnqualifiedId::IK_TemplateId:
2932    Diag(Name.getSourceRange().getBegin(), diag::err_using_decl_template_id)
2933      << SourceRange(Name.TemplateId->LAngleLoc, Name.TemplateId->RAngleLoc);
2934    return DeclPtrTy();
2935  }
2936
2937  DeclarationName TargetName = GetNameFromUnqualifiedId(Name);
2938  if (!TargetName)
2939    return DeclPtrTy();
2940
2941  // Warn about using declarations.
2942  // TODO: store that the declaration was written without 'using' and
2943  // talk about access decls instead of using decls in the
2944  // diagnostics.
2945  if (!HasUsingKeyword) {
2946    UsingLoc = Name.getSourceRange().getBegin();
2947
2948    Diag(UsingLoc, diag::warn_access_decl_deprecated)
2949      << CodeModificationHint::CreateInsertion(SS.getRange().getBegin(),
2950                                               "using ");
2951  }
2952
2953  NamedDecl *UD = BuildUsingDeclaration(S, AS, UsingLoc, SS,
2954                                        Name.getSourceRange().getBegin(),
2955                                        TargetName, AttrList,
2956                                        /* IsInstantiation */ false,
2957                                        IsTypeName, TypenameLoc);
2958  if (UD)
2959    PushOnScopeChains(UD, S, /*AddToContext*/ false);
2960
2961  return DeclPtrTy::make(UD);
2962}
2963
2964/// Determines whether to create a using shadow decl for a particular
2965/// decl, given the set of decls existing prior to this using lookup.
2966bool Sema::CheckUsingShadowDecl(UsingDecl *Using, NamedDecl *Orig,
2967                                const LookupResult &Previous) {
2968  // Diagnose finding a decl which is not from a base class of the
2969  // current class.  We do this now because there are cases where this
2970  // function will silently decide not to build a shadow decl, which
2971  // will pre-empt further diagnostics.
2972  //
2973  // We don't need to do this in C++0x because we do the check once on
2974  // the qualifier.
2975  //
2976  // FIXME: diagnose the following if we care enough:
2977  //   struct A { int foo; };
2978  //   struct B : A { using A::foo; };
2979  //   template <class T> struct C : A {};
2980  //   template <class T> struct D : C<T> { using B::foo; } // <---
2981  // This is invalid (during instantiation) in C++03 because B::foo
2982  // resolves to the using decl in B, which is not a base class of D<T>.
2983  // We can't diagnose it immediately because C<T> is an unknown
2984  // specialization.  The UsingShadowDecl in D<T> then points directly
2985  // to A::foo, which will look well-formed when we instantiate.
2986  // The right solution is to not collapse the shadow-decl chain.
2987  if (!getLangOptions().CPlusPlus0x && CurContext->isRecord()) {
2988    DeclContext *OrigDC = Orig->getDeclContext();
2989
2990    // Handle enums and anonymous structs.
2991    if (isa<EnumDecl>(OrigDC)) OrigDC = OrigDC->getParent();
2992    CXXRecordDecl *OrigRec = cast<CXXRecordDecl>(OrigDC);
2993    while (OrigRec->isAnonymousStructOrUnion())
2994      OrigRec = cast<CXXRecordDecl>(OrigRec->getDeclContext());
2995
2996    if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(OrigRec)) {
2997      if (OrigDC == CurContext) {
2998        Diag(Using->getLocation(),
2999             diag::err_using_decl_nested_name_specifier_is_current_class)
3000          << Using->getNestedNameRange();
3001        Diag(Orig->getLocation(), diag::note_using_decl_target);
3002        return true;
3003      }
3004
3005      Diag(Using->getNestedNameRange().getBegin(),
3006           diag::err_using_decl_nested_name_specifier_is_not_base_class)
3007        << Using->getTargetNestedNameDecl()
3008        << cast<CXXRecordDecl>(CurContext)
3009        << Using->getNestedNameRange();
3010      Diag(Orig->getLocation(), diag::note_using_decl_target);
3011      return true;
3012    }
3013  }
3014
3015  if (Previous.empty()) return false;
3016
3017  NamedDecl *Target = Orig;
3018  if (isa<UsingShadowDecl>(Target))
3019    Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
3020
3021  // If the target happens to be one of the previous declarations, we
3022  // don't have a conflict.
3023  //
3024  // FIXME: but we might be increasing its access, in which case we
3025  // should redeclare it.
3026  NamedDecl *NonTag = 0, *Tag = 0;
3027  for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
3028         I != E; ++I) {
3029    NamedDecl *D = (*I)->getUnderlyingDecl();
3030    if (D->getCanonicalDecl() == Target->getCanonicalDecl())
3031      return false;
3032
3033    (isa<TagDecl>(D) ? Tag : NonTag) = D;
3034  }
3035
3036  if (Target->isFunctionOrFunctionTemplate()) {
3037    FunctionDecl *FD;
3038    if (isa<FunctionTemplateDecl>(Target))
3039      FD = cast<FunctionTemplateDecl>(Target)->getTemplatedDecl();
3040    else
3041      FD = cast<FunctionDecl>(Target);
3042
3043    NamedDecl *OldDecl = 0;
3044    switch (CheckOverload(FD, Previous, OldDecl)) {
3045    case Ovl_Overload:
3046      return false;
3047
3048    case Ovl_NonFunction:
3049      Diag(Using->getLocation(), diag::err_using_decl_conflict);
3050      break;
3051
3052    // We found a decl with the exact signature.
3053    case Ovl_Match:
3054      if (isa<UsingShadowDecl>(OldDecl)) {
3055        // Silently ignore the possible conflict.
3056        return false;
3057      }
3058
3059      // If we're in a record, we want to hide the target, so we
3060      // return true (without a diagnostic) to tell the caller not to
3061      // build a shadow decl.
3062      if (CurContext->isRecord())
3063        return true;
3064
3065      // If we're not in a record, this is an error.
3066      Diag(Using->getLocation(), diag::err_using_decl_conflict);
3067      break;
3068    }
3069
3070    Diag(Target->getLocation(), diag::note_using_decl_target);
3071    Diag(OldDecl->getLocation(), diag::note_using_decl_conflict);
3072    return true;
3073  }
3074
3075  // Target is not a function.
3076
3077  if (isa<TagDecl>(Target)) {
3078    // No conflict between a tag and a non-tag.
3079    if (!Tag) return false;
3080
3081    Diag(Using->getLocation(), diag::err_using_decl_conflict);
3082    Diag(Target->getLocation(), diag::note_using_decl_target);
3083    Diag(Tag->getLocation(), diag::note_using_decl_conflict);
3084    return true;
3085  }
3086
3087  // No conflict between a tag and a non-tag.
3088  if (!NonTag) return false;
3089
3090  Diag(Using->getLocation(), diag::err_using_decl_conflict);
3091  Diag(Target->getLocation(), diag::note_using_decl_target);
3092  Diag(NonTag->getLocation(), diag::note_using_decl_conflict);
3093  return true;
3094}
3095
3096/// Builds a shadow declaration corresponding to a 'using' declaration.
3097UsingShadowDecl *Sema::BuildUsingShadowDecl(Scope *S,
3098                                            UsingDecl *UD,
3099                                            NamedDecl *Orig) {
3100
3101  // If we resolved to another shadow declaration, just coalesce them.
3102  NamedDecl *Target = Orig;
3103  if (isa<UsingShadowDecl>(Target)) {
3104    Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
3105    assert(!isa<UsingShadowDecl>(Target) && "nested shadow declaration");
3106  }
3107
3108  UsingShadowDecl *Shadow
3109    = UsingShadowDecl::Create(Context, CurContext,
3110                              UD->getLocation(), UD, Target);
3111  UD->addShadowDecl(Shadow);
3112
3113  if (S)
3114    PushOnScopeChains(Shadow, S);
3115  else
3116    CurContext->addDecl(Shadow);
3117  Shadow->setAccess(UD->getAccess());
3118
3119  if (Orig->isInvalidDecl() || UD->isInvalidDecl())
3120    Shadow->setInvalidDecl();
3121
3122  return Shadow;
3123}
3124
3125/// Hides a using shadow declaration.  This is required by the current
3126/// using-decl implementation when a resolvable using declaration in a
3127/// class is followed by a declaration which would hide or override
3128/// one or more of the using decl's targets; for example:
3129///
3130///   struct Base { void foo(int); };
3131///   struct Derived : Base {
3132///     using Base::foo;
3133///     void foo(int);
3134///   };
3135///
3136/// The governing language is C++03 [namespace.udecl]p12:
3137///
3138///   When a using-declaration brings names from a base class into a
3139///   derived class scope, member functions in the derived class
3140///   override and/or hide member functions with the same name and
3141///   parameter types in a base class (rather than conflicting).
3142///
3143/// There are two ways to implement this:
3144///   (1) optimistically create shadow decls when they're not hidden
3145///       by existing declarations, or
3146///   (2) don't create any shadow decls (or at least don't make them
3147///       visible) until we've fully parsed/instantiated the class.
3148/// The problem with (1) is that we might have to retroactively remove
3149/// a shadow decl, which requires several O(n) operations because the
3150/// decl structures are (very reasonably) not designed for removal.
3151/// (2) avoids this but is very fiddly and phase-dependent.
3152void Sema::HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow) {
3153  // Remove it from the DeclContext...
3154  Shadow->getDeclContext()->removeDecl(Shadow);
3155
3156  // ...and the scope, if applicable...
3157  if (S) {
3158    S->RemoveDecl(DeclPtrTy::make(static_cast<Decl*>(Shadow)));
3159    IdResolver.RemoveDecl(Shadow);
3160  }
3161
3162  // ...and the using decl.
3163  Shadow->getUsingDecl()->removeShadowDecl(Shadow);
3164
3165  // TODO: complain somehow if Shadow was used.  It shouldn't
3166  // be possible for this to happen, because
3167}
3168
3169/// Builds a using declaration.
3170///
3171/// \param IsInstantiation - Whether this call arises from an
3172///   instantiation of an unresolved using declaration.  We treat
3173///   the lookup differently for these declarations.
3174NamedDecl *Sema::BuildUsingDeclaration(Scope *S, AccessSpecifier AS,
3175                                       SourceLocation UsingLoc,
3176                                       const CXXScopeSpec &SS,
3177                                       SourceLocation IdentLoc,
3178                                       DeclarationName Name,
3179                                       AttributeList *AttrList,
3180                                       bool IsInstantiation,
3181                                       bool IsTypeName,
3182                                       SourceLocation TypenameLoc) {
3183  assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
3184  assert(IdentLoc.isValid() && "Invalid TargetName location.");
3185
3186  // FIXME: We ignore attributes for now.
3187  delete AttrList;
3188
3189  if (SS.isEmpty()) {
3190    Diag(IdentLoc, diag::err_using_requires_qualname);
3191    return 0;
3192  }
3193
3194  // Do the redeclaration lookup in the current scope.
3195  LookupResult Previous(*this, Name, IdentLoc, LookupUsingDeclName,
3196                        ForRedeclaration);
3197  Previous.setHideTags(false);
3198  if (S) {
3199    LookupName(Previous, S);
3200
3201    // It is really dumb that we have to do this.
3202    LookupResult::Filter F = Previous.makeFilter();
3203    while (F.hasNext()) {
3204      NamedDecl *D = F.next();
3205      if (!isDeclInScope(D, CurContext, S))
3206        F.erase();
3207    }
3208    F.done();
3209  } else {
3210    assert(IsInstantiation && "no scope in non-instantiation");
3211    assert(CurContext->isRecord() && "scope not record in instantiation");
3212    LookupQualifiedName(Previous, CurContext);
3213  }
3214
3215  NestedNameSpecifier *NNS =
3216    static_cast<NestedNameSpecifier *>(SS.getScopeRep());
3217
3218  // Check for invalid redeclarations.
3219  if (CheckUsingDeclRedeclaration(UsingLoc, IsTypeName, SS, IdentLoc, Previous))
3220    return 0;
3221
3222  // Check for bad qualifiers.
3223  if (CheckUsingDeclQualifier(UsingLoc, SS, IdentLoc))
3224    return 0;
3225
3226  DeclContext *LookupContext = computeDeclContext(SS);
3227  NamedDecl *D;
3228  if (!LookupContext) {
3229    if (IsTypeName) {
3230      // FIXME: not all declaration name kinds are legal here
3231      D = UnresolvedUsingTypenameDecl::Create(Context, CurContext,
3232                                              UsingLoc, TypenameLoc,
3233                                              SS.getRange(), NNS,
3234                                              IdentLoc, Name);
3235    } else {
3236      D = UnresolvedUsingValueDecl::Create(Context, CurContext,
3237                                           UsingLoc, SS.getRange(), NNS,
3238                                           IdentLoc, Name);
3239    }
3240  } else {
3241    D = UsingDecl::Create(Context, CurContext, IdentLoc,
3242                          SS.getRange(), UsingLoc, NNS, Name,
3243                          IsTypeName);
3244  }
3245  D->setAccess(AS);
3246  CurContext->addDecl(D);
3247
3248  if (!LookupContext) return D;
3249  UsingDecl *UD = cast<UsingDecl>(D);
3250
3251  if (RequireCompleteDeclContext(SS)) {
3252    UD->setInvalidDecl();
3253    return UD;
3254  }
3255
3256  // Look up the target name.
3257
3258  LookupResult R(*this, Name, IdentLoc, LookupOrdinaryName);
3259
3260  // Unlike most lookups, we don't always want to hide tag
3261  // declarations: tag names are visible through the using declaration
3262  // even if hidden by ordinary names, *except* in a dependent context
3263  // where it's important for the sanity of two-phase lookup.
3264  if (!IsInstantiation)
3265    R.setHideTags(false);
3266
3267  LookupQualifiedName(R, LookupContext);
3268
3269  if (R.empty()) {
3270    Diag(IdentLoc, diag::err_no_member)
3271      << Name << LookupContext << SS.getRange();
3272    UD->setInvalidDecl();
3273    return UD;
3274  }
3275
3276  if (R.isAmbiguous()) {
3277    UD->setInvalidDecl();
3278    return UD;
3279  }
3280
3281  if (IsTypeName) {
3282    // If we asked for a typename and got a non-type decl, error out.
3283    if (!R.getAsSingle<TypeDecl>()) {
3284      Diag(IdentLoc, diag::err_using_typename_non_type);
3285      for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
3286        Diag((*I)->getUnderlyingDecl()->getLocation(),
3287             diag::note_using_decl_target);
3288      UD->setInvalidDecl();
3289      return UD;
3290    }
3291  } else {
3292    // If we asked for a non-typename and we got a type, error out,
3293    // but only if this is an instantiation of an unresolved using
3294    // decl.  Otherwise just silently find the type name.
3295    if (IsInstantiation && R.getAsSingle<TypeDecl>()) {
3296      Diag(IdentLoc, diag::err_using_dependent_value_is_type);
3297      Diag(R.getFoundDecl()->getLocation(), diag::note_using_decl_target);
3298      UD->setInvalidDecl();
3299      return UD;
3300    }
3301  }
3302
3303  // C++0x N2914 [namespace.udecl]p6:
3304  // A using-declaration shall not name a namespace.
3305  if (R.getAsSingle<NamespaceDecl>()) {
3306    Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace)
3307      << SS.getRange();
3308    UD->setInvalidDecl();
3309    return UD;
3310  }
3311
3312  for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
3313    if (!CheckUsingShadowDecl(UD, *I, Previous))
3314      BuildUsingShadowDecl(S, UD, *I);
3315  }
3316
3317  return UD;
3318}
3319
3320/// Checks that the given using declaration is not an invalid
3321/// redeclaration.  Note that this is checking only for the using decl
3322/// itself, not for any ill-formedness among the UsingShadowDecls.
3323bool Sema::CheckUsingDeclRedeclaration(SourceLocation UsingLoc,
3324                                       bool isTypeName,
3325                                       const CXXScopeSpec &SS,
3326                                       SourceLocation NameLoc,
3327                                       const LookupResult &Prev) {
3328  // C++03 [namespace.udecl]p8:
3329  // C++0x [namespace.udecl]p10:
3330  //   A using-declaration is a declaration and can therefore be used
3331  //   repeatedly where (and only where) multiple declarations are
3332  //   allowed.
3333  // That's only in file contexts.
3334  if (CurContext->getLookupContext()->isFileContext())
3335    return false;
3336
3337  NestedNameSpecifier *Qual
3338    = static_cast<NestedNameSpecifier*>(SS.getScopeRep());
3339
3340  for (LookupResult::iterator I = Prev.begin(), E = Prev.end(); I != E; ++I) {
3341    NamedDecl *D = *I;
3342
3343    bool DTypename;
3344    NestedNameSpecifier *DQual;
3345    if (UsingDecl *UD = dyn_cast<UsingDecl>(D)) {
3346      DTypename = UD->isTypeName();
3347      DQual = UD->getTargetNestedNameDecl();
3348    } else if (UnresolvedUsingValueDecl *UD
3349                 = dyn_cast<UnresolvedUsingValueDecl>(D)) {
3350      DTypename = false;
3351      DQual = UD->getTargetNestedNameSpecifier();
3352    } else if (UnresolvedUsingTypenameDecl *UD
3353                 = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
3354      DTypename = true;
3355      DQual = UD->getTargetNestedNameSpecifier();
3356    } else continue;
3357
3358    // using decls differ if one says 'typename' and the other doesn't.
3359    // FIXME: non-dependent using decls?
3360    if (isTypeName != DTypename) continue;
3361
3362    // using decls differ if they name different scopes (but note that
3363    // template instantiation can cause this check to trigger when it
3364    // didn't before instantiation).
3365    if (Context.getCanonicalNestedNameSpecifier(Qual) !=
3366        Context.getCanonicalNestedNameSpecifier(DQual))
3367      continue;
3368
3369    Diag(NameLoc, diag::err_using_decl_redeclaration) << SS.getRange();
3370    Diag(D->getLocation(), diag::note_using_decl) << 1;
3371    return true;
3372  }
3373
3374  return false;
3375}
3376
3377
3378/// Checks that the given nested-name qualifier used in a using decl
3379/// in the current context is appropriately related to the current
3380/// scope.  If an error is found, diagnoses it and returns true.
3381bool Sema::CheckUsingDeclQualifier(SourceLocation UsingLoc,
3382                                   const CXXScopeSpec &SS,
3383                                   SourceLocation NameLoc) {
3384  DeclContext *NamedContext = computeDeclContext(SS);
3385
3386  if (!CurContext->isRecord()) {
3387    // C++03 [namespace.udecl]p3:
3388    // C++0x [namespace.udecl]p8:
3389    //   A using-declaration for a class member shall be a member-declaration.
3390
3391    // If we weren't able to compute a valid scope, it must be a
3392    // dependent class scope.
3393    if (!NamedContext || NamedContext->isRecord()) {
3394      Diag(NameLoc, diag::err_using_decl_can_not_refer_to_class_member)
3395        << SS.getRange();
3396      return true;
3397    }
3398
3399    // Otherwise, everything is known to be fine.
3400    return false;
3401  }
3402
3403  // The current scope is a record.
3404
3405  // If the named context is dependent, we can't decide much.
3406  if (!NamedContext) {
3407    // FIXME: in C++0x, we can diagnose if we can prove that the
3408    // nested-name-specifier does not refer to a base class, which is
3409    // still possible in some cases.
3410
3411    // Otherwise we have to conservatively report that things might be
3412    // okay.
3413    return false;
3414  }
3415
3416  if (!NamedContext->isRecord()) {
3417    // Ideally this would point at the last name in the specifier,
3418    // but we don't have that level of source info.
3419    Diag(SS.getRange().getBegin(),
3420         diag::err_using_decl_nested_name_specifier_is_not_class)
3421      << (NestedNameSpecifier*) SS.getScopeRep() << SS.getRange();
3422    return true;
3423  }
3424
3425  if (getLangOptions().CPlusPlus0x) {
3426    // C++0x [namespace.udecl]p3:
3427    //   In a using-declaration used as a member-declaration, the
3428    //   nested-name-specifier shall name a base class of the class
3429    //   being defined.
3430
3431    if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(
3432                                 cast<CXXRecordDecl>(NamedContext))) {
3433      if (CurContext == NamedContext) {
3434        Diag(NameLoc,
3435             diag::err_using_decl_nested_name_specifier_is_current_class)
3436          << SS.getRange();
3437        return true;
3438      }
3439
3440      Diag(SS.getRange().getBegin(),
3441           diag::err_using_decl_nested_name_specifier_is_not_base_class)
3442        << (NestedNameSpecifier*) SS.getScopeRep()
3443        << cast<CXXRecordDecl>(CurContext)
3444        << SS.getRange();
3445      return true;
3446    }
3447
3448    return false;
3449  }
3450
3451  // C++03 [namespace.udecl]p4:
3452  //   A using-declaration used as a member-declaration shall refer
3453  //   to a member of a base class of the class being defined [etc.].
3454
3455  // Salient point: SS doesn't have to name a base class as long as
3456  // lookup only finds members from base classes.  Therefore we can
3457  // diagnose here only if we can prove that that can't happen,
3458  // i.e. if the class hierarchies provably don't intersect.
3459
3460  // TODO: it would be nice if "definitely valid" results were cached
3461  // in the UsingDecl and UsingShadowDecl so that these checks didn't
3462  // need to be repeated.
3463
3464  struct UserData {
3465    llvm::DenseSet<const CXXRecordDecl*> Bases;
3466
3467    static bool collect(const CXXRecordDecl *Base, void *OpaqueData) {
3468      UserData *Data = reinterpret_cast<UserData*>(OpaqueData);
3469      Data->Bases.insert(Base);
3470      return true;
3471    }
3472
3473    bool hasDependentBases(const CXXRecordDecl *Class) {
3474      return !Class->forallBases(collect, this);
3475    }
3476
3477    /// Returns true if the base is dependent or is one of the
3478    /// accumulated base classes.
3479    static bool doesNotContain(const CXXRecordDecl *Base, void *OpaqueData) {
3480      UserData *Data = reinterpret_cast<UserData*>(OpaqueData);
3481      return !Data->Bases.count(Base);
3482    }
3483
3484    bool mightShareBases(const CXXRecordDecl *Class) {
3485      return Bases.count(Class) || !Class->forallBases(doesNotContain, this);
3486    }
3487  };
3488
3489  UserData Data;
3490
3491  // Returns false if we find a dependent base.
3492  if (Data.hasDependentBases(cast<CXXRecordDecl>(CurContext)))
3493    return false;
3494
3495  // Returns false if the class has a dependent base or if it or one
3496  // of its bases is present in the base set of the current context.
3497  if (Data.mightShareBases(cast<CXXRecordDecl>(NamedContext)))
3498    return false;
3499
3500  Diag(SS.getRange().getBegin(),
3501       diag::err_using_decl_nested_name_specifier_is_not_base_class)
3502    << (NestedNameSpecifier*) SS.getScopeRep()
3503    << cast<CXXRecordDecl>(CurContext)
3504    << SS.getRange();
3505
3506  return true;
3507}
3508
3509Sema::DeclPtrTy Sema::ActOnNamespaceAliasDef(Scope *S,
3510                                             SourceLocation NamespaceLoc,
3511                                             SourceLocation AliasLoc,
3512                                             IdentifierInfo *Alias,
3513                                             const CXXScopeSpec &SS,
3514                                             SourceLocation IdentLoc,
3515                                             IdentifierInfo *Ident) {
3516
3517  // Lookup the namespace name.
3518  LookupResult R(*this, Ident, IdentLoc, LookupNamespaceName);
3519  LookupParsedName(R, S, &SS);
3520
3521  // Check if we have a previous declaration with the same name.
3522  if (NamedDecl *PrevDecl
3523        = LookupSingleName(S, Alias, LookupOrdinaryName, ForRedeclaration)) {
3524    if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) {
3525      // We already have an alias with the same name that points to the same
3526      // namespace, so don't create a new one.
3527      if (!R.isAmbiguous() && !R.empty() &&
3528          AD->getNamespace() == getNamespaceDecl(R.getFoundDecl()))
3529        return DeclPtrTy();
3530    }
3531
3532    unsigned DiagID = isa<NamespaceDecl>(PrevDecl) ? diag::err_redefinition :
3533      diag::err_redefinition_different_kind;
3534    Diag(AliasLoc, DiagID) << Alias;
3535    Diag(PrevDecl->getLocation(), diag::note_previous_definition);
3536    return DeclPtrTy();
3537  }
3538
3539  if (R.isAmbiguous())
3540    return DeclPtrTy();
3541
3542  if (R.empty()) {
3543    Diag(NamespaceLoc, diag::err_expected_namespace_name) << SS.getRange();
3544    return DeclPtrTy();
3545  }
3546
3547  NamespaceAliasDecl *AliasDecl =
3548    NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc,
3549                               Alias, SS.getRange(),
3550                               (NestedNameSpecifier *)SS.getScopeRep(),
3551                               IdentLoc, R.getFoundDecl());
3552
3553  CurContext->addDecl(AliasDecl);
3554  return DeclPtrTy::make(AliasDecl);
3555}
3556
3557void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
3558                                            CXXConstructorDecl *Constructor) {
3559  assert((Constructor->isImplicit() && Constructor->isDefaultConstructor() &&
3560          !Constructor->isUsed()) &&
3561    "DefineImplicitDefaultConstructor - call it for implicit default ctor");
3562
3563  CXXRecordDecl *ClassDecl
3564    = cast<CXXRecordDecl>(Constructor->getDeclContext());
3565  assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor");
3566
3567  if (SetBaseOrMemberInitializers(Constructor, 0, 0, true)) {
3568    Diag(CurrentLocation, diag::note_member_synthesized_at)
3569      << CXXDefaultConstructor << Context.getTagDeclType(ClassDecl);
3570    Constructor->setInvalidDecl();
3571  } else {
3572    Constructor->setUsed();
3573  }
3574}
3575
3576void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation,
3577                                    CXXDestructorDecl *Destructor) {
3578  assert((Destructor->isImplicit() && !Destructor->isUsed()) &&
3579         "DefineImplicitDestructor - call it for implicit default dtor");
3580  CXXRecordDecl *ClassDecl = Destructor->getParent();
3581  assert(ClassDecl && "DefineImplicitDestructor - invalid destructor");
3582  // C++ [class.dtor] p5
3583  // Before the implicitly-declared default destructor for a class is
3584  // implicitly defined, all the implicitly-declared default destructors
3585  // for its base class and its non-static data members shall have been
3586  // implicitly defined.
3587  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
3588       E = ClassDecl->bases_end(); Base != E; ++Base) {
3589    CXXRecordDecl *BaseClassDecl
3590      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
3591    if (!BaseClassDecl->hasTrivialDestructor()) {
3592      if (CXXDestructorDecl *BaseDtor =
3593          const_cast<CXXDestructorDecl*>(BaseClassDecl->getDestructor(Context)))
3594        MarkDeclarationReferenced(CurrentLocation, BaseDtor);
3595      else
3596        assert(false &&
3597               "DefineImplicitDestructor - missing dtor in a base class");
3598    }
3599  }
3600
3601  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
3602       E = ClassDecl->field_end(); Field != E; ++Field) {
3603    QualType FieldType = Context.getCanonicalType((*Field)->getType());
3604    if (const ArrayType *Array = Context.getAsArrayType(FieldType))
3605      FieldType = Array->getElementType();
3606    if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) {
3607      CXXRecordDecl *FieldClassDecl
3608        = cast<CXXRecordDecl>(FieldClassType->getDecl());
3609      if (!FieldClassDecl->hasTrivialDestructor()) {
3610        if (CXXDestructorDecl *FieldDtor =
3611            const_cast<CXXDestructorDecl*>(
3612                                        FieldClassDecl->getDestructor(Context)))
3613          MarkDeclarationReferenced(CurrentLocation, FieldDtor);
3614        else
3615          assert(false &&
3616          "DefineImplicitDestructor - missing dtor in class of a data member");
3617      }
3618    }
3619  }
3620
3621  // FIXME: If CheckDestructor fails, we should emit a note about where the
3622  // implicit destructor was needed.
3623  if (CheckDestructor(Destructor)) {
3624    Diag(CurrentLocation, diag::note_member_synthesized_at)
3625      << CXXDestructor << Context.getTagDeclType(ClassDecl);
3626
3627    Destructor->setInvalidDecl();
3628    return;
3629  }
3630
3631  Destructor->setUsed();
3632}
3633
3634void Sema::DefineImplicitOverloadedAssign(SourceLocation CurrentLocation,
3635                                          CXXMethodDecl *MethodDecl) {
3636  assert((MethodDecl->isImplicit() && MethodDecl->isOverloadedOperator() &&
3637          MethodDecl->getOverloadedOperator() == OO_Equal &&
3638          !MethodDecl->isUsed()) &&
3639         "DefineImplicitOverloadedAssign - call it for implicit assignment op");
3640
3641  CXXRecordDecl *ClassDecl
3642    = cast<CXXRecordDecl>(MethodDecl->getDeclContext());
3643
3644  // C++[class.copy] p12
3645  // Before the implicitly-declared copy assignment operator for a class is
3646  // implicitly defined, all implicitly-declared copy assignment operators
3647  // for its direct base classes and its nonstatic data members shall have
3648  // been implicitly defined.
3649  bool err = false;
3650  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
3651       E = ClassDecl->bases_end(); Base != E; ++Base) {
3652    CXXRecordDecl *BaseClassDecl
3653      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
3654    if (CXXMethodDecl *BaseAssignOpMethod =
3655          getAssignOperatorMethod(CurrentLocation, MethodDecl->getParamDecl(0),
3656                                  BaseClassDecl))
3657      MarkDeclarationReferenced(CurrentLocation, BaseAssignOpMethod);
3658  }
3659  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
3660       E = ClassDecl->field_end(); Field != E; ++Field) {
3661    QualType FieldType = Context.getCanonicalType((*Field)->getType());
3662    if (const ArrayType *Array = Context.getAsArrayType(FieldType))
3663      FieldType = Array->getElementType();
3664    if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) {
3665      CXXRecordDecl *FieldClassDecl
3666        = cast<CXXRecordDecl>(FieldClassType->getDecl());
3667      if (CXXMethodDecl *FieldAssignOpMethod =
3668          getAssignOperatorMethod(CurrentLocation, MethodDecl->getParamDecl(0),
3669                                  FieldClassDecl))
3670        MarkDeclarationReferenced(CurrentLocation, FieldAssignOpMethod);
3671    } else if (FieldType->isReferenceType()) {
3672      Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
3673      << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
3674      Diag(Field->getLocation(), diag::note_declared_at);
3675      Diag(CurrentLocation, diag::note_first_required_here);
3676      err = true;
3677    } else if (FieldType.isConstQualified()) {
3678      Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
3679      << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
3680      Diag(Field->getLocation(), diag::note_declared_at);
3681      Diag(CurrentLocation, diag::note_first_required_here);
3682      err = true;
3683    }
3684  }
3685  if (!err)
3686    MethodDecl->setUsed();
3687}
3688
3689CXXMethodDecl *
3690Sema::getAssignOperatorMethod(SourceLocation CurrentLocation,
3691                              ParmVarDecl *ParmDecl,
3692                              CXXRecordDecl *ClassDecl) {
3693  QualType LHSType = Context.getTypeDeclType(ClassDecl);
3694  QualType RHSType(LHSType);
3695  // If class's assignment operator argument is const/volatile qualified,
3696  // look for operator = (const/volatile B&). Otherwise, look for
3697  // operator = (B&).
3698  RHSType = Context.getCVRQualifiedType(RHSType,
3699                                     ParmDecl->getType().getCVRQualifiers());
3700  ExprOwningPtr<Expr> LHS(this,  new (Context) DeclRefExpr(ParmDecl,
3701                                                           LHSType,
3702                                                           SourceLocation()));
3703  ExprOwningPtr<Expr> RHS(this,  new (Context) DeclRefExpr(ParmDecl,
3704                                                           RHSType,
3705                                                           CurrentLocation));
3706  Expr *Args[2] = { &*LHS, &*RHS };
3707  OverloadCandidateSet CandidateSet;
3708  AddMemberOperatorCandidates(clang::OO_Equal, SourceLocation(), Args, 2,
3709                              CandidateSet);
3710  OverloadCandidateSet::iterator Best;
3711  if (BestViableFunction(CandidateSet, CurrentLocation, Best) == OR_Success)
3712    return cast<CXXMethodDecl>(Best->Function);
3713  assert(false &&
3714         "getAssignOperatorMethod - copy assignment operator method not found");
3715  return 0;
3716}
3717
3718void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
3719                                   CXXConstructorDecl *CopyConstructor,
3720                                   unsigned TypeQuals) {
3721  assert((CopyConstructor->isImplicit() &&
3722          CopyConstructor->isCopyConstructor(Context, TypeQuals) &&
3723          !CopyConstructor->isUsed()) &&
3724         "DefineImplicitCopyConstructor - call it for implicit copy ctor");
3725
3726  CXXRecordDecl *ClassDecl
3727    = cast<CXXRecordDecl>(CopyConstructor->getDeclContext());
3728  assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor");
3729  // C++ [class.copy] p209
3730  // Before the implicitly-declared copy constructor for a class is
3731  // implicitly defined, all the implicitly-declared copy constructors
3732  // for its base class and its non-static data members shall have been
3733  // implicitly defined.
3734  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin();
3735       Base != ClassDecl->bases_end(); ++Base) {
3736    CXXRecordDecl *BaseClassDecl
3737      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
3738    if (CXXConstructorDecl *BaseCopyCtor =
3739        BaseClassDecl->getCopyConstructor(Context, TypeQuals))
3740      MarkDeclarationReferenced(CurrentLocation, BaseCopyCtor);
3741  }
3742  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
3743                                  FieldEnd = ClassDecl->field_end();
3744       Field != FieldEnd; ++Field) {
3745    QualType FieldType = Context.getCanonicalType((*Field)->getType());
3746    if (const ArrayType *Array = Context.getAsArrayType(FieldType))
3747      FieldType = Array->getElementType();
3748    if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) {
3749      CXXRecordDecl *FieldClassDecl
3750        = cast<CXXRecordDecl>(FieldClassType->getDecl());
3751      if (CXXConstructorDecl *FieldCopyCtor =
3752          FieldClassDecl->getCopyConstructor(Context, TypeQuals))
3753        MarkDeclarationReferenced(CurrentLocation, FieldCopyCtor);
3754    }
3755  }
3756  CopyConstructor->setUsed();
3757}
3758
3759Sema::OwningExprResult
3760Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
3761                            CXXConstructorDecl *Constructor,
3762                            MultiExprArg ExprArgs,
3763                            bool RequiresZeroInit) {
3764  bool Elidable = false;
3765
3766  // C++ [class.copy]p15:
3767  //   Whenever a temporary class object is copied using a copy constructor, and
3768  //   this object and the copy have the same cv-unqualified type, an
3769  //   implementation is permitted to treat the original and the copy as two
3770  //   different ways of referring to the same object and not perform a copy at
3771  //   all, even if the class copy constructor or destructor have side effects.
3772
3773  // FIXME: Is this enough?
3774  if (Constructor->isCopyConstructor(Context)) {
3775    Expr *E = ((Expr **)ExprArgs.get())[0];
3776    while (CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(E))
3777      E = BE->getSubExpr();
3778    if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
3779      if (ICE->getCastKind() == CastExpr::CK_NoOp)
3780        E = ICE->getSubExpr();
3781
3782    if (CallExpr *CE = dyn_cast<CallExpr>(E))
3783      Elidable = !CE->getCallReturnType()->isReferenceType();
3784    else if (isa<CXXTemporaryObjectExpr>(E))
3785      Elidable = true;
3786  }
3787
3788  return BuildCXXConstructExpr(ConstructLoc, DeclInitType, Constructor,
3789                               Elidable, move(ExprArgs), RequiresZeroInit);
3790}
3791
3792/// BuildCXXConstructExpr - Creates a complete call to a constructor,
3793/// including handling of its default argument expressions.
3794Sema::OwningExprResult
3795Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
3796                            CXXConstructorDecl *Constructor, bool Elidable,
3797                            MultiExprArg ExprArgs,
3798                            bool RequiresZeroInit) {
3799  unsigned NumExprs = ExprArgs.size();
3800  Expr **Exprs = (Expr **)ExprArgs.release();
3801
3802  MarkDeclarationReferenced(ConstructLoc, Constructor);
3803  return Owned(CXXConstructExpr::Create(Context, DeclInitType, ConstructLoc,
3804                                        Constructor, Elidable, Exprs, NumExprs,
3805                                        RequiresZeroInit));
3806}
3807
3808Sema::OwningExprResult
3809Sema::BuildCXXTemporaryObjectExpr(CXXConstructorDecl *Constructor,
3810                                  QualType Ty,
3811                                  SourceLocation TyBeginLoc,
3812                                  MultiExprArg Args,
3813                                  SourceLocation RParenLoc) {
3814  unsigned NumExprs = Args.size();
3815  Expr **Exprs = (Expr **)Args.release();
3816
3817  MarkDeclarationReferenced(TyBeginLoc, Constructor);
3818  return Owned(new (Context) CXXTemporaryObjectExpr(Context, Constructor, Ty,
3819                                                    TyBeginLoc, Exprs,
3820                                                    NumExprs, RParenLoc));
3821}
3822
3823
3824bool Sema::InitializeVarWithConstructor(VarDecl *VD,
3825                                        CXXConstructorDecl *Constructor,
3826                                        MultiExprArg Exprs) {
3827  OwningExprResult TempResult =
3828    BuildCXXConstructExpr(VD->getLocation(), VD->getType(), Constructor,
3829                          move(Exprs));
3830  if (TempResult.isInvalid())
3831    return true;
3832
3833  Expr *Temp = TempResult.takeAs<Expr>();
3834  MarkDeclarationReferenced(VD->getLocation(), Constructor);
3835  Temp = MaybeCreateCXXExprWithTemporaries(Temp);
3836  VD->setInit(Context, Temp);
3837
3838  return false;
3839}
3840
3841void Sema::FinalizeVarWithDestructor(VarDecl *VD, QualType DeclInitType) {
3842  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(
3843                                  DeclInitType->getAs<RecordType>()->getDecl());
3844  if (!ClassDecl->hasTrivialDestructor())
3845    if (CXXDestructorDecl *Destructor =
3846        const_cast<CXXDestructorDecl*>(ClassDecl->getDestructor(Context)))
3847      MarkDeclarationReferenced(VD->getLocation(), Destructor);
3848}
3849
3850/// AddCXXDirectInitializerToDecl - This action is called immediately after
3851/// ActOnDeclarator, when a C++ direct initializer is present.
3852/// e.g: "int x(1);"
3853void Sema::AddCXXDirectInitializerToDecl(DeclPtrTy Dcl,
3854                                         SourceLocation LParenLoc,
3855                                         MultiExprArg Exprs,
3856                                         SourceLocation *CommaLocs,
3857                                         SourceLocation RParenLoc) {
3858  unsigned NumExprs = Exprs.size();
3859  assert(NumExprs != 0 && Exprs.get() && "missing expressions");
3860  Decl *RealDecl = Dcl.getAs<Decl>();
3861
3862  // If there is no declaration, there was an error parsing it.  Just ignore
3863  // the initializer.
3864  if (RealDecl == 0)
3865    return;
3866
3867  VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl);
3868  if (!VDecl) {
3869    Diag(RealDecl->getLocation(), diag::err_illegal_initializer);
3870    RealDecl->setInvalidDecl();
3871    return;
3872  }
3873
3874  // We will represent direct-initialization similarly to copy-initialization:
3875  //    int x(1);  -as-> int x = 1;
3876  //    ClassType x(a,b,c); -as-> ClassType x = ClassType(a,b,c);
3877  //
3878  // Clients that want to distinguish between the two forms, can check for
3879  // direct initializer using VarDecl::hasCXXDirectInitializer().
3880  // A major benefit is that clients that don't particularly care about which
3881  // exactly form was it (like the CodeGen) can handle both cases without
3882  // special case code.
3883
3884  // If either the declaration has a dependent type or if any of the expressions
3885  // is type-dependent, we represent the initialization via a ParenListExpr for
3886  // later use during template instantiation.
3887  if (VDecl->getType()->isDependentType() ||
3888      Expr::hasAnyTypeDependentArguments((Expr **)Exprs.get(), Exprs.size())) {
3889    // Let clients know that initialization was done with a direct initializer.
3890    VDecl->setCXXDirectInitializer(true);
3891
3892    // Store the initialization expressions as a ParenListExpr.
3893    unsigned NumExprs = Exprs.size();
3894    VDecl->setInit(Context,
3895                   new (Context) ParenListExpr(Context, LParenLoc,
3896                                               (Expr **)Exprs.release(),
3897                                               NumExprs, RParenLoc));
3898    return;
3899  }
3900
3901
3902  // C++ 8.5p11:
3903  // The form of initialization (using parentheses or '=') is generally
3904  // insignificant, but does matter when the entity being initialized has a
3905  // class type.
3906  QualType DeclInitType = VDecl->getType();
3907  if (const ArrayType *Array = Context.getAsArrayType(DeclInitType))
3908    DeclInitType = Context.getBaseElementType(Array);
3909
3910  // FIXME: This isn't the right place to complete the type.
3911  if (RequireCompleteType(VDecl->getLocation(), VDecl->getType(),
3912                          diag::err_typecheck_decl_incomplete_type)) {
3913    VDecl->setInvalidDecl();
3914    return;
3915  }
3916
3917  if (VDecl->getType()->isRecordType()) {
3918    ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(*this);
3919
3920    CXXConstructorDecl *Constructor
3921      = PerformInitializationByConstructor(DeclInitType,
3922                                           move(Exprs),
3923                                           VDecl->getLocation(),
3924                                           SourceRange(VDecl->getLocation(),
3925                                                       RParenLoc),
3926                                           VDecl->getDeclName(),
3927                      InitializationKind::CreateDirect(VDecl->getLocation(),
3928                                                       LParenLoc,
3929                                                       RParenLoc),
3930                                           ConstructorArgs);
3931    if (!Constructor)
3932      RealDecl->setInvalidDecl();
3933    else {
3934      VDecl->setCXXDirectInitializer(true);
3935      if (InitializeVarWithConstructor(VDecl, Constructor,
3936                                       move_arg(ConstructorArgs)))
3937        RealDecl->setInvalidDecl();
3938      FinalizeVarWithDestructor(VDecl, DeclInitType);
3939    }
3940    return;
3941  }
3942
3943  if (NumExprs > 1) {
3944    Diag(CommaLocs[0], diag::err_builtin_direct_init_more_than_one_arg)
3945      << SourceRange(VDecl->getLocation(), RParenLoc);
3946    RealDecl->setInvalidDecl();
3947    return;
3948  }
3949
3950  // Let clients know that initialization was done with a direct initializer.
3951  VDecl->setCXXDirectInitializer(true);
3952
3953  assert(NumExprs == 1 && "Expected 1 expression");
3954  // Set the init expression, handles conversions.
3955  AddInitializerToDecl(Dcl, ExprArg(*this, Exprs.release()[0]),
3956                       /*DirectInit=*/true);
3957}
3958
3959/// \brief Add the applicable constructor candidates for an initialization
3960/// by constructor.
3961static void AddConstructorInitializationCandidates(Sema &SemaRef,
3962                                                   QualType ClassType,
3963                                                   Expr **Args,
3964                                                   unsigned NumArgs,
3965                                                   InitializationKind Kind,
3966                                           OverloadCandidateSet &CandidateSet) {
3967  // C++ [dcl.init]p14:
3968  //   If the initialization is direct-initialization, or if it is
3969  //   copy-initialization where the cv-unqualified version of the
3970  //   source type is the same class as, or a derived class of, the
3971  //   class of the destination, constructors are considered. The
3972  //   applicable constructors are enumerated (13.3.1.3), and the
3973  //   best one is chosen through overload resolution (13.3). The
3974  //   constructor so selected is called to initialize the object,
3975  //   with the initializer expression(s) as its argument(s). If no
3976  //   constructor applies, or the overload resolution is ambiguous,
3977  //   the initialization is ill-formed.
3978  const RecordType *ClassRec = ClassType->getAs<RecordType>();
3979  assert(ClassRec && "Can only initialize a class type here");
3980
3981  // FIXME: When we decide not to synthesize the implicitly-declared
3982  // constructors, we'll need to make them appear here.
3983
3984  const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl());
3985  DeclarationName ConstructorName
3986    = SemaRef.Context.DeclarationNames.getCXXConstructorName(
3987              SemaRef.Context.getCanonicalType(ClassType).getUnqualifiedType());
3988  DeclContext::lookup_const_iterator Con, ConEnd;
3989  for (llvm::tie(Con, ConEnd) = ClassDecl->lookup(ConstructorName);
3990       Con != ConEnd; ++Con) {
3991    // Find the constructor (which may be a template).
3992    CXXConstructorDecl *Constructor = 0;
3993    FunctionTemplateDecl *ConstructorTmpl= dyn_cast<FunctionTemplateDecl>(*Con);
3994    if (ConstructorTmpl)
3995      Constructor
3996      = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl());
3997    else
3998      Constructor = cast<CXXConstructorDecl>(*Con);
3999
4000    if ((Kind.getKind() == InitializationKind::IK_Direct) ||
4001        (Kind.getKind() == InitializationKind::IK_Value) ||
4002        (Kind.getKind() == InitializationKind::IK_Copy &&
4003         Constructor->isConvertingConstructor(/*AllowExplicit=*/false)) ||
4004        ((Kind.getKind() == InitializationKind::IK_Default) &&
4005         Constructor->isDefaultConstructor())) {
4006      if (ConstructorTmpl)
4007        SemaRef.AddTemplateOverloadCandidate(ConstructorTmpl,
4008                                             /*ExplicitArgs*/ 0,
4009                                             Args, NumArgs, CandidateSet);
4010      else
4011        SemaRef.AddOverloadCandidate(Constructor, Args, NumArgs, CandidateSet);
4012    }
4013  }
4014}
4015
4016/// \brief Attempt to perform initialization by constructor
4017/// (C++ [dcl.init]p14), which may occur as part of direct-initialization or
4018/// copy-initialization.
4019///
4020/// This routine determines whether initialization by constructor is possible,
4021/// but it does not emit any diagnostics in the case where the initialization
4022/// is ill-formed.
4023///
4024/// \param ClassType the type of the object being initialized, which must have
4025/// class type.
4026///
4027/// \param Args the arguments provided to initialize the object
4028///
4029/// \param NumArgs the number of arguments provided to initialize the object
4030///
4031/// \param Kind the type of initialization being performed
4032///
4033/// \returns the constructor used to initialize the object, if successful.
4034/// Otherwise, emits a diagnostic and returns NULL.
4035CXXConstructorDecl *
4036Sema::TryInitializationByConstructor(QualType ClassType,
4037                                     Expr **Args, unsigned NumArgs,
4038                                     SourceLocation Loc,
4039                                     InitializationKind Kind) {
4040  // Build the overload candidate set
4041  OverloadCandidateSet CandidateSet;
4042  AddConstructorInitializationCandidates(*this, ClassType, Args, NumArgs, Kind,
4043                                         CandidateSet);
4044
4045  // Determine whether we found a constructor we can use.
4046  OverloadCandidateSet::iterator Best;
4047  switch (BestViableFunction(CandidateSet, Loc, Best)) {
4048    case OR_Success:
4049    case OR_Deleted:
4050      // We found a constructor. Return it.
4051      return cast<CXXConstructorDecl>(Best->Function);
4052
4053    case OR_No_Viable_Function:
4054    case OR_Ambiguous:
4055      // Overload resolution failed. Return nothing.
4056      return 0;
4057  }
4058
4059  // Silence GCC warning
4060  return 0;
4061}
4062
4063/// \brief Perform initialization by constructor (C++ [dcl.init]p14), which
4064/// may occur as part of direct-initialization or copy-initialization.
4065///
4066/// \param ClassType the type of the object being initialized, which must have
4067/// class type.
4068///
4069/// \param ArgsPtr the arguments provided to initialize the object
4070///
4071/// \param Loc the source location where the initialization occurs
4072///
4073/// \param Range the source range that covers the entire initialization
4074///
4075/// \param InitEntity the name of the entity being initialized, if known
4076///
4077/// \param Kind the type of initialization being performed
4078///
4079/// \param ConvertedArgs a vector that will be filled in with the
4080/// appropriately-converted arguments to the constructor (if initialization
4081/// succeeded).
4082///
4083/// \returns the constructor used to initialize the object, if successful.
4084/// Otherwise, emits a diagnostic and returns NULL.
4085CXXConstructorDecl *
4086Sema::PerformInitializationByConstructor(QualType ClassType,
4087                                         MultiExprArg ArgsPtr,
4088                                         SourceLocation Loc, SourceRange Range,
4089                                         DeclarationName InitEntity,
4090                                         InitializationKind Kind,
4091                      ASTOwningVector<&ActionBase::DeleteExpr> &ConvertedArgs) {
4092
4093  // Build the overload candidate set
4094  Expr **Args = (Expr **)ArgsPtr.get();
4095  unsigned NumArgs = ArgsPtr.size();
4096  OverloadCandidateSet CandidateSet;
4097  AddConstructorInitializationCandidates(*this, ClassType, Args, NumArgs, Kind,
4098                                         CandidateSet);
4099
4100  OverloadCandidateSet::iterator Best;
4101  switch (BestViableFunction(CandidateSet, Loc, Best)) {
4102  case OR_Success:
4103    // We found a constructor. Break out so that we can convert the arguments
4104    // appropriately.
4105    break;
4106
4107  case OR_No_Viable_Function:
4108    if (InitEntity)
4109      Diag(Loc, diag::err_ovl_no_viable_function_in_init)
4110        << InitEntity << Range;
4111    else
4112      Diag(Loc, diag::err_ovl_no_viable_function_in_init)
4113        << ClassType << Range;
4114    PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false);
4115    return 0;
4116
4117  case OR_Ambiguous:
4118    if (InitEntity)
4119      Diag(Loc, diag::err_ovl_ambiguous_init) << InitEntity << Range;
4120    else
4121      Diag(Loc, diag::err_ovl_ambiguous_init) << ClassType << Range;
4122    PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true);
4123    return 0;
4124
4125  case OR_Deleted:
4126    if (InitEntity)
4127      Diag(Loc, diag::err_ovl_deleted_init)
4128        << Best->Function->isDeleted()
4129        << InitEntity << Range;
4130    else {
4131      const CXXRecordDecl *RD =
4132          cast<CXXRecordDecl>(ClassType->getAs<RecordType>()->getDecl());
4133      Diag(Loc, diag::err_ovl_deleted_init)
4134        << Best->Function->isDeleted()
4135        << RD->getDeclName() << Range;
4136    }
4137    PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true);
4138    return 0;
4139  }
4140
4141  // Convert the arguments, fill in default arguments, etc.
4142  CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
4143  if (CompleteConstructorCall(Constructor, move(ArgsPtr), Loc, ConvertedArgs))
4144    return 0;
4145
4146  return Constructor;
4147}
4148
4149/// \brief Given a constructor and the set of arguments provided for the
4150/// constructor, convert the arguments and add any required default arguments
4151/// to form a proper call to this constructor.
4152///
4153/// \returns true if an error occurred, false otherwise.
4154bool
4155Sema::CompleteConstructorCall(CXXConstructorDecl *Constructor,
4156                              MultiExprArg ArgsPtr,
4157                              SourceLocation Loc,
4158                     ASTOwningVector<&ActionBase::DeleteExpr> &ConvertedArgs) {
4159  // FIXME: This duplicates a lot of code from Sema::ConvertArgumentsForCall.
4160  unsigned NumArgs = ArgsPtr.size();
4161  Expr **Args = (Expr **)ArgsPtr.get();
4162
4163  const FunctionProtoType *Proto
4164    = Constructor->getType()->getAs<FunctionProtoType>();
4165  assert(Proto && "Constructor without a prototype?");
4166  unsigned NumArgsInProto = Proto->getNumArgs();
4167
4168  // If too few arguments are available, we'll fill in the rest with defaults.
4169  if (NumArgs < NumArgsInProto)
4170    ConvertedArgs.reserve(NumArgsInProto);
4171  else
4172    ConvertedArgs.reserve(NumArgs);
4173
4174  VariadicCallType CallType =
4175    Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
4176  llvm::SmallVector<Expr *, 8> AllArgs;
4177  bool Invalid = GatherArgumentsForCall(Loc, Constructor,
4178                                        Proto, 0, Args, NumArgs, AllArgs,
4179                                        CallType);
4180  for (unsigned i =0, size = AllArgs.size(); i < size; i++)
4181    ConvertedArgs.push_back(AllArgs[i]);
4182  return Invalid;
4183}
4184
4185/// CompareReferenceRelationship - Compare the two types T1 and T2 to
4186/// determine whether they are reference-related,
4187/// reference-compatible, reference-compatible with added
4188/// qualification, or incompatible, for use in C++ initialization by
4189/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
4190/// type, and the first type (T1) is the pointee type of the reference
4191/// type being initialized.
4192Sema::ReferenceCompareResult
4193Sema::CompareReferenceRelationship(SourceLocation Loc,
4194                                   QualType OrigT1, QualType OrigT2,
4195                                   bool& DerivedToBase) {
4196  assert(!OrigT1->isReferenceType() &&
4197    "T1 must be the pointee type of the reference type");
4198  assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type");
4199
4200  QualType T1 = Context.getCanonicalType(OrigT1);
4201  QualType T2 = Context.getCanonicalType(OrigT2);
4202  QualType UnqualT1 = T1.getLocalUnqualifiedType();
4203  QualType UnqualT2 = T2.getLocalUnqualifiedType();
4204
4205  // C++ [dcl.init.ref]p4:
4206  //   Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
4207  //   reference-related to "cv2 T2" if T1 is the same type as T2, or
4208  //   T1 is a base class of T2.
4209  if (UnqualT1 == UnqualT2)
4210    DerivedToBase = false;
4211  else if (!RequireCompleteType(Loc, OrigT1, PDiag()) &&
4212           !RequireCompleteType(Loc, OrigT2, PDiag()) &&
4213           IsDerivedFrom(UnqualT2, UnqualT1))
4214    DerivedToBase = true;
4215  else
4216    return Ref_Incompatible;
4217
4218  // At this point, we know that T1 and T2 are reference-related (at
4219  // least).
4220
4221  // C++ [dcl.init.ref]p4:
4222  //   "cv1 T1" is reference-compatible with "cv2 T2" if T1 is
4223  //   reference-related to T2 and cv1 is the same cv-qualification
4224  //   as, or greater cv-qualification than, cv2. For purposes of
4225  //   overload resolution, cases for which cv1 is greater
4226  //   cv-qualification than cv2 are identified as
4227  //   reference-compatible with added qualification (see 13.3.3.2).
4228  if (T1.getCVRQualifiers() == T2.getCVRQualifiers())
4229    return Ref_Compatible;
4230  else if (T1.isMoreQualifiedThan(T2))
4231    return Ref_Compatible_With_Added_Qualification;
4232  else
4233    return Ref_Related;
4234}
4235
4236/// CheckReferenceInit - Check the initialization of a reference
4237/// variable with the given initializer (C++ [dcl.init.ref]). Init is
4238/// the initializer (either a simple initializer or an initializer
4239/// list), and DeclType is the type of the declaration. When ICS is
4240/// non-null, this routine will compute the implicit conversion
4241/// sequence according to C++ [over.ics.ref] and will not produce any
4242/// diagnostics; when ICS is null, it will emit diagnostics when any
4243/// errors are found. Either way, a return value of true indicates
4244/// that there was a failure, a return value of false indicates that
4245/// the reference initialization succeeded.
4246///
4247/// When @p SuppressUserConversions, user-defined conversions are
4248/// suppressed.
4249/// When @p AllowExplicit, we also permit explicit user-defined
4250/// conversion functions.
4251/// When @p ForceRValue, we unconditionally treat the initializer as an rvalue.
4252/// When @p IgnoreBaseAccess, we don't do access control on to-base conversion.
4253/// This is used when this is called from a C-style cast.
4254bool
4255Sema::CheckReferenceInit(Expr *&Init, QualType DeclType,
4256                         SourceLocation DeclLoc,
4257                         bool SuppressUserConversions,
4258                         bool AllowExplicit, bool ForceRValue,
4259                         ImplicitConversionSequence *ICS,
4260                         bool IgnoreBaseAccess) {
4261  assert(DeclType->isReferenceType() && "Reference init needs a reference");
4262
4263  QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType();
4264  QualType T2 = Init->getType();
4265
4266  // If the initializer is the address of an overloaded function, try
4267  // to resolve the overloaded function. If all goes well, T2 is the
4268  // type of the resulting function.
4269  if (Context.getCanonicalType(T2) == Context.OverloadTy) {
4270    FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Init, DeclType,
4271                                                          ICS != 0);
4272    if (Fn) {
4273      // Since we're performing this reference-initialization for
4274      // real, update the initializer with the resulting function.
4275      if (!ICS) {
4276        if (DiagnoseUseOfDecl(Fn, DeclLoc))
4277          return true;
4278
4279        Init = FixOverloadedFunctionReference(Init, Fn);
4280      }
4281
4282      T2 = Fn->getType();
4283    }
4284  }
4285
4286  // Compute some basic properties of the types and the initializer.
4287  bool isRValRef = DeclType->isRValueReferenceType();
4288  bool DerivedToBase = false;
4289  Expr::isLvalueResult InitLvalue = ForceRValue ? Expr::LV_InvalidExpression :
4290                                                  Init->isLvalue(Context);
4291  ReferenceCompareResult RefRelationship
4292    = CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase);
4293
4294  // Most paths end in a failed conversion.
4295  if (ICS)
4296    ICS->ConversionKind = ImplicitConversionSequence::BadConversion;
4297
4298  // C++ [dcl.init.ref]p5:
4299  //   A reference to type "cv1 T1" is initialized by an expression
4300  //   of type "cv2 T2" as follows:
4301
4302  //     -- If the initializer expression
4303
4304  // Rvalue references cannot bind to lvalues (N2812).
4305  // There is absolutely no situation where they can. In particular, note that
4306  // this is ill-formed, even if B has a user-defined conversion to A&&:
4307  //   B b;
4308  //   A&& r = b;
4309  if (isRValRef && InitLvalue == Expr::LV_Valid) {
4310    if (!ICS)
4311      Diag(DeclLoc, diag::err_lvalue_to_rvalue_ref)
4312        << Init->getSourceRange();
4313    return true;
4314  }
4315
4316  bool BindsDirectly = false;
4317  //       -- is an lvalue (but is not a bit-field), and "cv1 T1" is
4318  //          reference-compatible with "cv2 T2," or
4319  //
4320  // Note that the bit-field check is skipped if we are just computing
4321  // the implicit conversion sequence (C++ [over.best.ics]p2).
4322  if (InitLvalue == Expr::LV_Valid && (ICS || !Init->getBitField()) &&
4323      RefRelationship >= Ref_Compatible_With_Added_Qualification) {
4324    BindsDirectly = true;
4325
4326    if (ICS) {
4327      // C++ [over.ics.ref]p1:
4328      //   When a parameter of reference type binds directly (8.5.3)
4329      //   to an argument expression, the implicit conversion sequence
4330      //   is the identity conversion, unless the argument expression
4331      //   has a type that is a derived class of the parameter type,
4332      //   in which case the implicit conversion sequence is a
4333      //   derived-to-base Conversion (13.3.3.1).
4334      ICS->ConversionKind = ImplicitConversionSequence::StandardConversion;
4335      ICS->Standard.First = ICK_Identity;
4336      ICS->Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity;
4337      ICS->Standard.Third = ICK_Identity;
4338      ICS->Standard.FromTypePtr = T2.getAsOpaquePtr();
4339      ICS->Standard.ToTypePtr = T1.getAsOpaquePtr();
4340      ICS->Standard.ReferenceBinding = true;
4341      ICS->Standard.DirectBinding = true;
4342      ICS->Standard.RRefBinding = false;
4343      ICS->Standard.CopyConstructor = 0;
4344
4345      // Nothing more to do: the inaccessibility/ambiguity check for
4346      // derived-to-base conversions is suppressed when we're
4347      // computing the implicit conversion sequence (C++
4348      // [over.best.ics]p2).
4349      return false;
4350    } else {
4351      // Perform the conversion.
4352      CastExpr::CastKind CK = CastExpr::CK_NoOp;
4353      if (DerivedToBase)
4354        CK = CastExpr::CK_DerivedToBase;
4355      else if(CheckExceptionSpecCompatibility(Init, T1))
4356        return true;
4357      ImpCastExprToType(Init, T1, CK, /*isLvalue=*/true);
4358    }
4359  }
4360
4361  //       -- has a class type (i.e., T2 is a class type) and can be
4362  //          implicitly converted to an lvalue of type "cv3 T3,"
4363  //          where "cv1 T1" is reference-compatible with "cv3 T3"
4364  //          92) (this conversion is selected by enumerating the
4365  //          applicable conversion functions (13.3.1.6) and choosing
4366  //          the best one through overload resolution (13.3)),
4367  if (!isRValRef && !SuppressUserConversions && T2->isRecordType() &&
4368      !RequireCompleteType(DeclLoc, T2, 0)) {
4369    CXXRecordDecl *T2RecordDecl
4370      = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl());
4371
4372    OverloadCandidateSet CandidateSet;
4373    const UnresolvedSet *Conversions
4374      = T2RecordDecl->getVisibleConversionFunctions();
4375    for (UnresolvedSet::iterator I = Conversions->begin(),
4376           E = Conversions->end(); I != E; ++I) {
4377      NamedDecl *D = *I;
4378      CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4379      if (isa<UsingShadowDecl>(D))
4380        D = cast<UsingShadowDecl>(D)->getTargetDecl();
4381
4382      FunctionTemplateDecl *ConvTemplate
4383        = dyn_cast<FunctionTemplateDecl>(D);
4384      CXXConversionDecl *Conv;
4385      if (ConvTemplate)
4386        Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4387      else
4388        Conv = cast<CXXConversionDecl>(D);
4389
4390      // If the conversion function doesn't return a reference type,
4391      // it can't be considered for this conversion.
4392      if (Conv->getConversionType()->isLValueReferenceType() &&
4393          (AllowExplicit || !Conv->isExplicit())) {
4394        if (ConvTemplate)
4395          AddTemplateConversionCandidate(ConvTemplate, ActingDC,
4396                                         Init, DeclType, CandidateSet);
4397        else
4398          AddConversionCandidate(Conv, ActingDC, Init, DeclType, CandidateSet);
4399      }
4400    }
4401
4402    OverloadCandidateSet::iterator Best;
4403    switch (BestViableFunction(CandidateSet, DeclLoc, Best)) {
4404    case OR_Success:
4405      // This is a direct binding.
4406      BindsDirectly = true;
4407
4408      if (ICS) {
4409        // C++ [over.ics.ref]p1:
4410        //
4411        //   [...] If the parameter binds directly to the result of
4412        //   applying a conversion function to the argument
4413        //   expression, the implicit conversion sequence is a
4414        //   user-defined conversion sequence (13.3.3.1.2), with the
4415        //   second standard conversion sequence either an identity
4416        //   conversion or, if the conversion function returns an
4417        //   entity of a type that is a derived class of the parameter
4418        //   type, a derived-to-base Conversion.
4419        ICS->ConversionKind = ImplicitConversionSequence::UserDefinedConversion;
4420        ICS->UserDefined.Before = Best->Conversions[0].Standard;
4421        ICS->UserDefined.After = Best->FinalConversion;
4422        ICS->UserDefined.ConversionFunction = Best->Function;
4423        ICS->UserDefined.EllipsisConversion = false;
4424        assert(ICS->UserDefined.After.ReferenceBinding &&
4425               ICS->UserDefined.After.DirectBinding &&
4426               "Expected a direct reference binding!");
4427        return false;
4428      } else {
4429        OwningExprResult InitConversion =
4430          BuildCXXCastArgument(DeclLoc, QualType(),
4431                               CastExpr::CK_UserDefinedConversion,
4432                               cast<CXXMethodDecl>(Best->Function),
4433                               Owned(Init));
4434        Init = InitConversion.takeAs<Expr>();
4435
4436        if (CheckExceptionSpecCompatibility(Init, T1))
4437          return true;
4438        ImpCastExprToType(Init, T1, CastExpr::CK_UserDefinedConversion,
4439                          /*isLvalue=*/true);
4440      }
4441      break;
4442
4443    case OR_Ambiguous:
4444      if (ICS) {
4445        for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
4446             Cand != CandidateSet.end(); ++Cand)
4447          if (Cand->Viable)
4448            ICS->ConversionFunctionSet.push_back(Cand->Function);
4449        break;
4450      }
4451      Diag(DeclLoc, diag::err_ref_init_ambiguous) << DeclType << Init->getType()
4452            << Init->getSourceRange();
4453      PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true);
4454      return true;
4455
4456    case OR_No_Viable_Function:
4457    case OR_Deleted:
4458      // There was no suitable conversion, or we found a deleted
4459      // conversion; continue with other checks.
4460      break;
4461    }
4462  }
4463
4464  if (BindsDirectly) {
4465    // C++ [dcl.init.ref]p4:
4466    //   [...] In all cases where the reference-related or
4467    //   reference-compatible relationship of two types is used to
4468    //   establish the validity of a reference binding, and T1 is a
4469    //   base class of T2, a program that necessitates such a binding
4470    //   is ill-formed if T1 is an inaccessible (clause 11) or
4471    //   ambiguous (10.2) base class of T2.
4472    //
4473    // Note that we only check this condition when we're allowed to
4474    // complain about errors, because we should not be checking for
4475    // ambiguity (or inaccessibility) unless the reference binding
4476    // actually happens.
4477    if (DerivedToBase)
4478      return CheckDerivedToBaseConversion(T2, T1, DeclLoc,
4479                                          Init->getSourceRange(),
4480                                          IgnoreBaseAccess);
4481    else
4482      return false;
4483  }
4484
4485  //     -- Otherwise, the reference shall be to a non-volatile const
4486  //        type (i.e., cv1 shall be const), or the reference shall be an
4487  //        rvalue reference and the initializer expression shall be an rvalue.
4488  if (!isRValRef && T1.getCVRQualifiers() != Qualifiers::Const) {
4489    if (!ICS)
4490      Diag(DeclLoc, diag::err_not_reference_to_const_init)
4491        << T1 << int(InitLvalue != Expr::LV_Valid)
4492        << T2 << Init->getSourceRange();
4493    return true;
4494  }
4495
4496  //       -- If the initializer expression is an rvalue, with T2 a
4497  //          class type, and "cv1 T1" is reference-compatible with
4498  //          "cv2 T2," the reference is bound in one of the
4499  //          following ways (the choice is implementation-defined):
4500  //
4501  //          -- The reference is bound to the object represented by
4502  //             the rvalue (see 3.10) or to a sub-object within that
4503  //             object.
4504  //
4505  //          -- A temporary of type "cv1 T2" [sic] is created, and
4506  //             a constructor is called to copy the entire rvalue
4507  //             object into the temporary. The reference is bound to
4508  //             the temporary or to a sub-object within the
4509  //             temporary.
4510  //
4511  //          The constructor that would be used to make the copy
4512  //          shall be callable whether or not the copy is actually
4513  //          done.
4514  //
4515  // Note that C++0x [dcl.init.ref]p5 takes away this implementation
4516  // freedom, so we will always take the first option and never build
4517  // a temporary in this case. FIXME: We will, however, have to check
4518  // for the presence of a copy constructor in C++98/03 mode.
4519  if (InitLvalue != Expr::LV_Valid && T2->isRecordType() &&
4520      RefRelationship >= Ref_Compatible_With_Added_Qualification) {
4521    if (ICS) {
4522      ICS->ConversionKind = ImplicitConversionSequence::StandardConversion;
4523      ICS->Standard.First = ICK_Identity;
4524      ICS->Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity;
4525      ICS->Standard.Third = ICK_Identity;
4526      ICS->Standard.FromTypePtr = T2.getAsOpaquePtr();
4527      ICS->Standard.ToTypePtr = T1.getAsOpaquePtr();
4528      ICS->Standard.ReferenceBinding = true;
4529      ICS->Standard.DirectBinding = false;
4530      ICS->Standard.RRefBinding = isRValRef;
4531      ICS->Standard.CopyConstructor = 0;
4532    } else {
4533      CastExpr::CastKind CK = CastExpr::CK_NoOp;
4534      if (DerivedToBase)
4535        CK = CastExpr::CK_DerivedToBase;
4536      else if(CheckExceptionSpecCompatibility(Init, T1))
4537        return true;
4538      ImpCastExprToType(Init, T1, CK, /*isLvalue=*/false);
4539    }
4540    return false;
4541  }
4542
4543  //       -- Otherwise, a temporary of type "cv1 T1" is created and
4544  //          initialized from the initializer expression using the
4545  //          rules for a non-reference copy initialization (8.5). The
4546  //          reference is then bound to the temporary. If T1 is
4547  //          reference-related to T2, cv1 must be the same
4548  //          cv-qualification as, or greater cv-qualification than,
4549  //          cv2; otherwise, the program is ill-formed.
4550  if (RefRelationship == Ref_Related) {
4551    // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
4552    // we would be reference-compatible or reference-compatible with
4553    // added qualification. But that wasn't the case, so the reference
4554    // initialization fails.
4555    if (!ICS)
4556      Diag(DeclLoc, diag::err_reference_init_drops_quals)
4557        << T1 << int(InitLvalue != Expr::LV_Valid)
4558        << T2 << Init->getSourceRange();
4559    return true;
4560  }
4561
4562  // If at least one of the types is a class type, the types are not
4563  // related, and we aren't allowed any user conversions, the
4564  // reference binding fails. This case is important for breaking
4565  // recursion, since TryImplicitConversion below will attempt to
4566  // create a temporary through the use of a copy constructor.
4567  if (SuppressUserConversions && RefRelationship == Ref_Incompatible &&
4568      (T1->isRecordType() || T2->isRecordType())) {
4569    if (!ICS)
4570      Diag(DeclLoc, diag::err_typecheck_convert_incompatible)
4571        << DeclType << Init->getType() << AA_Initializing << Init->getSourceRange();
4572    return true;
4573  }
4574
4575  // Actually try to convert the initializer to T1.
4576  if (ICS) {
4577    // C++ [over.ics.ref]p2:
4578    //
4579    //   When a parameter of reference type is not bound directly to
4580    //   an argument expression, the conversion sequence is the one
4581    //   required to convert the argument expression to the
4582    //   underlying type of the reference according to
4583    //   13.3.3.1. Conceptually, this conversion sequence corresponds
4584    //   to copy-initializing a temporary of the underlying type with
4585    //   the argument expression. Any difference in top-level
4586    //   cv-qualification is subsumed by the initialization itself
4587    //   and does not constitute a conversion.
4588    *ICS = TryImplicitConversion(Init, T1, SuppressUserConversions,
4589                                 /*AllowExplicit=*/false,
4590                                 /*ForceRValue=*/false,
4591                                 /*InOverloadResolution=*/false);
4592
4593    // Of course, that's still a reference binding.
4594    if (ICS->ConversionKind == ImplicitConversionSequence::StandardConversion) {
4595      ICS->Standard.ReferenceBinding = true;
4596      ICS->Standard.RRefBinding = isRValRef;
4597    } else if (ICS->ConversionKind ==
4598              ImplicitConversionSequence::UserDefinedConversion) {
4599      ICS->UserDefined.After.ReferenceBinding = true;
4600      ICS->UserDefined.After.RRefBinding = isRValRef;
4601    }
4602    return ICS->ConversionKind == ImplicitConversionSequence::BadConversion;
4603  } else {
4604    ImplicitConversionSequence Conversions;
4605    bool badConversion = PerformImplicitConversion(Init, T1, AA_Initializing,
4606                                                   false, false,
4607                                                   Conversions);
4608    if (badConversion) {
4609      if ((Conversions.ConversionKind  ==
4610            ImplicitConversionSequence::BadConversion)
4611          && !Conversions.ConversionFunctionSet.empty()) {
4612        Diag(DeclLoc,
4613             diag::err_lvalue_to_rvalue_ambig_ref) << Init->getSourceRange();
4614        for (int j = Conversions.ConversionFunctionSet.size()-1;
4615             j >= 0; j--) {
4616          FunctionDecl *Func = Conversions.ConversionFunctionSet[j];
4617          Diag(Func->getLocation(), diag::err_ovl_candidate);
4618        }
4619      }
4620      else {
4621        if (isRValRef)
4622          Diag(DeclLoc, diag::err_lvalue_to_rvalue_ref)
4623            << Init->getSourceRange();
4624        else
4625          Diag(DeclLoc, diag::err_invalid_initialization)
4626            << DeclType << Init->getType() << Init->getSourceRange();
4627      }
4628    }
4629    return badConversion;
4630  }
4631}
4632
4633static inline bool
4634CheckOperatorNewDeleteDeclarationScope(Sema &SemaRef,
4635                                       const FunctionDecl *FnDecl) {
4636  const DeclContext *DC = FnDecl->getDeclContext()->getLookupContext();
4637  if (isa<NamespaceDecl>(DC)) {
4638    return SemaRef.Diag(FnDecl->getLocation(),
4639                        diag::err_operator_new_delete_declared_in_namespace)
4640      << FnDecl->getDeclName();
4641  }
4642
4643  if (isa<TranslationUnitDecl>(DC) &&
4644      FnDecl->getStorageClass() == FunctionDecl::Static) {
4645    return SemaRef.Diag(FnDecl->getLocation(),
4646                        diag::err_operator_new_delete_declared_static)
4647      << FnDecl->getDeclName();
4648  }
4649
4650  return false;
4651}
4652
4653static inline bool
4654CheckOperatorNewDeleteTypes(Sema &SemaRef, const FunctionDecl *FnDecl,
4655                            CanQualType ExpectedResultType,
4656                            CanQualType ExpectedFirstParamType,
4657                            unsigned DependentParamTypeDiag,
4658                            unsigned InvalidParamTypeDiag) {
4659  QualType ResultType =
4660    FnDecl->getType()->getAs<FunctionType>()->getResultType();
4661
4662  // Check that the result type is not dependent.
4663  if (ResultType->isDependentType())
4664    return SemaRef.Diag(FnDecl->getLocation(),
4665                        diag::err_operator_new_delete_dependent_result_type)
4666    << FnDecl->getDeclName() << ExpectedResultType;
4667
4668  // Check that the result type is what we expect.
4669  if (SemaRef.Context.getCanonicalType(ResultType) != ExpectedResultType)
4670    return SemaRef.Diag(FnDecl->getLocation(),
4671                        diag::err_operator_new_delete_invalid_result_type)
4672    << FnDecl->getDeclName() << ExpectedResultType;
4673
4674  // A function template must have at least 2 parameters.
4675  if (FnDecl->getDescribedFunctionTemplate() && FnDecl->getNumParams() < 2)
4676    return SemaRef.Diag(FnDecl->getLocation(),
4677                      diag::err_operator_new_delete_template_too_few_parameters)
4678        << FnDecl->getDeclName();
4679
4680  // The function decl must have at least 1 parameter.
4681  if (FnDecl->getNumParams() == 0)
4682    return SemaRef.Diag(FnDecl->getLocation(),
4683                        diag::err_operator_new_delete_too_few_parameters)
4684      << FnDecl->getDeclName();
4685
4686  // Check the the first parameter type is not dependent.
4687  QualType FirstParamType = FnDecl->getParamDecl(0)->getType();
4688  if (FirstParamType->isDependentType())
4689    return SemaRef.Diag(FnDecl->getLocation(), DependentParamTypeDiag)
4690      << FnDecl->getDeclName() << ExpectedFirstParamType;
4691
4692  // Check that the first parameter type is what we expect.
4693  if (SemaRef.Context.getCanonicalType(FirstParamType) !=
4694      ExpectedFirstParamType)
4695    return SemaRef.Diag(FnDecl->getLocation(), InvalidParamTypeDiag)
4696    << FnDecl->getDeclName() << ExpectedFirstParamType;
4697
4698  return false;
4699}
4700
4701static bool
4702CheckOperatorNewDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
4703  // C++ [basic.stc.dynamic.allocation]p1:
4704  //   A program is ill-formed if an allocation function is declared in a
4705  //   namespace scope other than global scope or declared static in global
4706  //   scope.
4707  if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
4708    return true;
4709
4710  CanQualType SizeTy =
4711    SemaRef.Context.getCanonicalType(SemaRef.Context.getSizeType());
4712
4713  // C++ [basic.stc.dynamic.allocation]p1:
4714  //  The return type shall be void*. The first parameter shall have type
4715  //  std::size_t.
4716  if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidPtrTy,
4717                                  SizeTy,
4718                                  diag::err_operator_new_dependent_param_type,
4719                                  diag::err_operator_new_param_type))
4720    return true;
4721
4722  // C++ [basic.stc.dynamic.allocation]p1:
4723  //  The first parameter shall not have an associated default argument.
4724  if (FnDecl->getParamDecl(0)->hasDefaultArg())
4725    return SemaRef.Diag(FnDecl->getLocation(),
4726                        diag::err_operator_new_default_arg)
4727      << FnDecl->getDeclName() << FnDecl->getParamDecl(0)->getDefaultArgRange();
4728
4729  return false;
4730}
4731
4732static bool
4733CheckOperatorDeleteDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
4734  // C++ [basic.stc.dynamic.deallocation]p1:
4735  //   A program is ill-formed if deallocation functions are declared in a
4736  //   namespace scope other than global scope or declared static in global
4737  //   scope.
4738  if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
4739    return true;
4740
4741  // C++ [basic.stc.dynamic.deallocation]p2:
4742  //   Each deallocation function shall return void and its first parameter
4743  //   shall be void*.
4744  if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidTy,
4745                                  SemaRef.Context.VoidPtrTy,
4746                                 diag::err_operator_delete_dependent_param_type,
4747                                 diag::err_operator_delete_param_type))
4748    return true;
4749
4750  QualType FirstParamType = FnDecl->getParamDecl(0)->getType();
4751  if (FirstParamType->isDependentType())
4752    return SemaRef.Diag(FnDecl->getLocation(),
4753                        diag::err_operator_delete_dependent_param_type)
4754    << FnDecl->getDeclName() << SemaRef.Context.VoidPtrTy;
4755
4756  if (SemaRef.Context.getCanonicalType(FirstParamType) !=
4757      SemaRef.Context.VoidPtrTy)
4758    return SemaRef.Diag(FnDecl->getLocation(),
4759                        diag::err_operator_delete_param_type)
4760      << FnDecl->getDeclName() << SemaRef.Context.VoidPtrTy;
4761
4762  return false;
4763}
4764
4765/// CheckOverloadedOperatorDeclaration - Check whether the declaration
4766/// of this overloaded operator is well-formed. If so, returns false;
4767/// otherwise, emits appropriate diagnostics and returns true.
4768bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) {
4769  assert(FnDecl && FnDecl->isOverloadedOperator() &&
4770         "Expected an overloaded operator declaration");
4771
4772  OverloadedOperatorKind Op = FnDecl->getOverloadedOperator();
4773
4774  // C++ [over.oper]p5:
4775  //   The allocation and deallocation functions, operator new,
4776  //   operator new[], operator delete and operator delete[], are
4777  //   described completely in 3.7.3. The attributes and restrictions
4778  //   found in the rest of this subclause do not apply to them unless
4779  //   explicitly stated in 3.7.3.
4780  if (Op == OO_Delete || Op == OO_Array_Delete)
4781    return CheckOperatorDeleteDeclaration(*this, FnDecl);
4782
4783  if (Op == OO_New || Op == OO_Array_New)
4784    return CheckOperatorNewDeclaration(*this, FnDecl);
4785
4786  // C++ [over.oper]p6:
4787  //   An operator function shall either be a non-static member
4788  //   function or be a non-member function and have at least one
4789  //   parameter whose type is a class, a reference to a class, an
4790  //   enumeration, or a reference to an enumeration.
4791  if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) {
4792    if (MethodDecl->isStatic())
4793      return Diag(FnDecl->getLocation(),
4794                  diag::err_operator_overload_static) << FnDecl->getDeclName();
4795  } else {
4796    bool ClassOrEnumParam = false;
4797    for (FunctionDecl::param_iterator Param = FnDecl->param_begin(),
4798                                   ParamEnd = FnDecl->param_end();
4799         Param != ParamEnd; ++Param) {
4800      QualType ParamType = (*Param)->getType().getNonReferenceType();
4801      if (ParamType->isDependentType() || ParamType->isRecordType() ||
4802          ParamType->isEnumeralType()) {
4803        ClassOrEnumParam = true;
4804        break;
4805      }
4806    }
4807
4808    if (!ClassOrEnumParam)
4809      return Diag(FnDecl->getLocation(),
4810                  diag::err_operator_overload_needs_class_or_enum)
4811        << FnDecl->getDeclName();
4812  }
4813
4814  // C++ [over.oper]p8:
4815  //   An operator function cannot have default arguments (8.3.6),
4816  //   except where explicitly stated below.
4817  //
4818  // Only the function-call operator allows default arguments
4819  // (C++ [over.call]p1).
4820  if (Op != OO_Call) {
4821    for (FunctionDecl::param_iterator Param = FnDecl->param_begin();
4822         Param != FnDecl->param_end(); ++Param) {
4823      if ((*Param)->hasDefaultArg())
4824        return Diag((*Param)->getLocation(),
4825                    diag::err_operator_overload_default_arg)
4826          << FnDecl->getDeclName() << (*Param)->getDefaultArgRange();
4827    }
4828  }
4829
4830  static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = {
4831    { false, false, false }
4832#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
4833    , { Unary, Binary, MemberOnly }
4834#include "clang/Basic/OperatorKinds.def"
4835  };
4836
4837  bool CanBeUnaryOperator = OperatorUses[Op][0];
4838  bool CanBeBinaryOperator = OperatorUses[Op][1];
4839  bool MustBeMemberOperator = OperatorUses[Op][2];
4840
4841  // C++ [over.oper]p8:
4842  //   [...] Operator functions cannot have more or fewer parameters
4843  //   than the number required for the corresponding operator, as
4844  //   described in the rest of this subclause.
4845  unsigned NumParams = FnDecl->getNumParams()
4846                     + (isa<CXXMethodDecl>(FnDecl)? 1 : 0);
4847  if (Op != OO_Call &&
4848      ((NumParams == 1 && !CanBeUnaryOperator) ||
4849       (NumParams == 2 && !CanBeBinaryOperator) ||
4850       (NumParams < 1) || (NumParams > 2))) {
4851    // We have the wrong number of parameters.
4852    unsigned ErrorKind;
4853    if (CanBeUnaryOperator && CanBeBinaryOperator) {
4854      ErrorKind = 2;  // 2 -> unary or binary.
4855    } else if (CanBeUnaryOperator) {
4856      ErrorKind = 0;  // 0 -> unary
4857    } else {
4858      assert(CanBeBinaryOperator &&
4859             "All non-call overloaded operators are unary or binary!");
4860      ErrorKind = 1;  // 1 -> binary
4861    }
4862
4863    return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be)
4864      << FnDecl->getDeclName() << NumParams << ErrorKind;
4865  }
4866
4867  // Overloaded operators other than operator() cannot be variadic.
4868  if (Op != OO_Call &&
4869      FnDecl->getType()->getAs<FunctionProtoType>()->isVariadic()) {
4870    return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic)
4871      << FnDecl->getDeclName();
4872  }
4873
4874  // Some operators must be non-static member functions.
4875  if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) {
4876    return Diag(FnDecl->getLocation(),
4877                diag::err_operator_overload_must_be_member)
4878      << FnDecl->getDeclName();
4879  }
4880
4881  // C++ [over.inc]p1:
4882  //   The user-defined function called operator++ implements the
4883  //   prefix and postfix ++ operator. If this function is a member
4884  //   function with no parameters, or a non-member function with one
4885  //   parameter of class or enumeration type, it defines the prefix
4886  //   increment operator ++ for objects of that type. If the function
4887  //   is a member function with one parameter (which shall be of type
4888  //   int) or a non-member function with two parameters (the second
4889  //   of which shall be of type int), it defines the postfix
4890  //   increment operator ++ for objects of that type.
4891  if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) {
4892    ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1);
4893    bool ParamIsInt = false;
4894    if (const BuiltinType *BT = LastParam->getType()->getAs<BuiltinType>())
4895      ParamIsInt = BT->getKind() == BuiltinType::Int;
4896
4897    if (!ParamIsInt)
4898      return Diag(LastParam->getLocation(),
4899                  diag::err_operator_overload_post_incdec_must_be_int)
4900        << LastParam->getType() << (Op == OO_MinusMinus);
4901  }
4902
4903  // Notify the class if it got an assignment operator.
4904  if (Op == OO_Equal) {
4905    // Would have returned earlier otherwise.
4906    assert(isa<CXXMethodDecl>(FnDecl) &&
4907      "Overloaded = not member, but not filtered.");
4908    CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
4909    Method->getParent()->addedAssignmentOperator(Context, Method);
4910  }
4911
4912  return false;
4913}
4914
4915/// ActOnStartLinkageSpecification - Parsed the beginning of a C++
4916/// linkage specification, including the language and (if present)
4917/// the '{'. ExternLoc is the location of the 'extern', LangLoc is
4918/// the location of the language string literal, which is provided
4919/// by Lang/StrSize. LBraceLoc, if valid, provides the location of
4920/// the '{' brace. Otherwise, this linkage specification does not
4921/// have any braces.
4922Sema::DeclPtrTy Sema::ActOnStartLinkageSpecification(Scope *S,
4923                                                     SourceLocation ExternLoc,
4924                                                     SourceLocation LangLoc,
4925                                                     const char *Lang,
4926                                                     unsigned StrSize,
4927                                                     SourceLocation LBraceLoc) {
4928  LinkageSpecDecl::LanguageIDs Language;
4929  if (strncmp(Lang, "\"C\"", StrSize) == 0)
4930    Language = LinkageSpecDecl::lang_c;
4931  else if (strncmp(Lang, "\"C++\"", StrSize) == 0)
4932    Language = LinkageSpecDecl::lang_cxx;
4933  else {
4934    Diag(LangLoc, diag::err_bad_language);
4935    return DeclPtrTy();
4936  }
4937
4938  // FIXME: Add all the various semantics of linkage specifications
4939
4940  LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext,
4941                                               LangLoc, Language,
4942                                               LBraceLoc.isValid());
4943  CurContext->addDecl(D);
4944  PushDeclContext(S, D);
4945  return DeclPtrTy::make(D);
4946}
4947
4948/// ActOnFinishLinkageSpecification - Completely the definition of
4949/// the C++ linkage specification LinkageSpec. If RBraceLoc is
4950/// valid, it's the position of the closing '}' brace in a linkage
4951/// specification that uses braces.
4952Sema::DeclPtrTy Sema::ActOnFinishLinkageSpecification(Scope *S,
4953                                                      DeclPtrTy LinkageSpec,
4954                                                      SourceLocation RBraceLoc) {
4955  if (LinkageSpec)
4956    PopDeclContext();
4957  return LinkageSpec;
4958}
4959
4960/// \brief Perform semantic analysis for the variable declaration that
4961/// occurs within a C++ catch clause, returning the newly-created
4962/// variable.
4963VarDecl *Sema::BuildExceptionDeclaration(Scope *S, QualType ExDeclType,
4964                                         TypeSourceInfo *TInfo,
4965                                         IdentifierInfo *Name,
4966                                         SourceLocation Loc,
4967                                         SourceRange Range) {
4968  bool Invalid = false;
4969
4970  // Arrays and functions decay.
4971  if (ExDeclType->isArrayType())
4972    ExDeclType = Context.getArrayDecayedType(ExDeclType);
4973  else if (ExDeclType->isFunctionType())
4974    ExDeclType = Context.getPointerType(ExDeclType);
4975
4976  // C++ 15.3p1: The exception-declaration shall not denote an incomplete type.
4977  // The exception-declaration shall not denote a pointer or reference to an
4978  // incomplete type, other than [cv] void*.
4979  // N2844 forbids rvalue references.
4980  if (!ExDeclType->isDependentType() && ExDeclType->isRValueReferenceType()) {
4981    Diag(Loc, diag::err_catch_rvalue_ref) << Range;
4982    Invalid = true;
4983  }
4984
4985  QualType BaseType = ExDeclType;
4986  int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference
4987  unsigned DK = diag::err_catch_incomplete;
4988  if (const PointerType *Ptr = BaseType->getAs<PointerType>()) {
4989    BaseType = Ptr->getPointeeType();
4990    Mode = 1;
4991    DK = diag::err_catch_incomplete_ptr;
4992  } else if (const ReferenceType *Ref = BaseType->getAs<ReferenceType>()) {
4993    // For the purpose of error recovery, we treat rvalue refs like lvalue refs.
4994    BaseType = Ref->getPointeeType();
4995    Mode = 2;
4996    DK = diag::err_catch_incomplete_ref;
4997  }
4998  if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) &&
4999      !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK))
5000    Invalid = true;
5001
5002  if (!Invalid && !ExDeclType->isDependentType() &&
5003      RequireNonAbstractType(Loc, ExDeclType,
5004                             diag::err_abstract_type_in_decl,
5005                             AbstractVariableType))
5006    Invalid = true;
5007
5008  // FIXME: Need to test for ability to copy-construct and destroy the
5009  // exception variable.
5010
5011  // FIXME: Need to check for abstract classes.
5012
5013  VarDecl *ExDecl = VarDecl::Create(Context, CurContext, Loc,
5014                                    Name, ExDeclType, TInfo, VarDecl::None);
5015
5016  if (Invalid)
5017    ExDecl->setInvalidDecl();
5018
5019  return ExDecl;
5020}
5021
5022/// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch
5023/// handler.
5024Sema::DeclPtrTy Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D) {
5025  TypeSourceInfo *TInfo = 0;
5026  QualType ExDeclType = GetTypeForDeclarator(D, S, &TInfo);
5027
5028  bool Invalid = D.isInvalidType();
5029  IdentifierInfo *II = D.getIdentifier();
5030  if (NamedDecl *PrevDecl = LookupSingleName(S, II, LookupOrdinaryName)) {
5031    // The scope should be freshly made just for us. There is just no way
5032    // it contains any previous declaration.
5033    assert(!S->isDeclScope(DeclPtrTy::make(PrevDecl)));
5034    if (PrevDecl->isTemplateParameter()) {
5035      // Maybe we will complain about the shadowed template parameter.
5036      DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
5037    }
5038  }
5039
5040  if (D.getCXXScopeSpec().isSet() && !Invalid) {
5041    Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator)
5042      << D.getCXXScopeSpec().getRange();
5043    Invalid = true;
5044  }
5045
5046  VarDecl *ExDecl = BuildExceptionDeclaration(S, ExDeclType, TInfo,
5047                                              D.getIdentifier(),
5048                                              D.getIdentifierLoc(),
5049                                            D.getDeclSpec().getSourceRange());
5050
5051  if (Invalid)
5052    ExDecl->setInvalidDecl();
5053
5054  // Add the exception declaration into this scope.
5055  if (II)
5056    PushOnScopeChains(ExDecl, S);
5057  else
5058    CurContext->addDecl(ExDecl);
5059
5060  ProcessDeclAttributes(S, ExDecl, D);
5061  return DeclPtrTy::make(ExDecl);
5062}
5063
5064Sema::DeclPtrTy Sema::ActOnStaticAssertDeclaration(SourceLocation AssertLoc,
5065                                                   ExprArg assertexpr,
5066                                                   ExprArg assertmessageexpr) {
5067  Expr *AssertExpr = (Expr *)assertexpr.get();
5068  StringLiteral *AssertMessage =
5069    cast<StringLiteral>((Expr *)assertmessageexpr.get());
5070
5071  if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent()) {
5072    llvm::APSInt Value(32);
5073    if (!AssertExpr->isIntegerConstantExpr(Value, Context)) {
5074      Diag(AssertLoc, diag::err_static_assert_expression_is_not_constant) <<
5075        AssertExpr->getSourceRange();
5076      return DeclPtrTy();
5077    }
5078
5079    if (Value == 0) {
5080      Diag(AssertLoc, diag::err_static_assert_failed)
5081        << AssertMessage->getString() << AssertExpr->getSourceRange();
5082    }
5083  }
5084
5085  assertexpr.release();
5086  assertmessageexpr.release();
5087  Decl *Decl = StaticAssertDecl::Create(Context, CurContext, AssertLoc,
5088                                        AssertExpr, AssertMessage);
5089
5090  CurContext->addDecl(Decl);
5091  return DeclPtrTy::make(Decl);
5092}
5093
5094/// Handle a friend type declaration.  This works in tandem with
5095/// ActOnTag.
5096///
5097/// Notes on friend class templates:
5098///
5099/// We generally treat friend class declarations as if they were
5100/// declaring a class.  So, for example, the elaborated type specifier
5101/// in a friend declaration is required to obey the restrictions of a
5102/// class-head (i.e. no typedefs in the scope chain), template
5103/// parameters are required to match up with simple template-ids, &c.
5104/// However, unlike when declaring a template specialization, it's
5105/// okay to refer to a template specialization without an empty
5106/// template parameter declaration, e.g.
5107///   friend class A<T>::B<unsigned>;
5108/// We permit this as a special case; if there are any template
5109/// parameters present at all, require proper matching, i.e.
5110///   template <> template <class T> friend class A<int>::B;
5111Sema::DeclPtrTy Sema::ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS,
5112                                          MultiTemplateParamsArg TempParams) {
5113  SourceLocation Loc = DS.getSourceRange().getBegin();
5114
5115  assert(DS.isFriendSpecified());
5116  assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
5117
5118  // Try to convert the decl specifier to a type.  This works for
5119  // friend templates because ActOnTag never produces a ClassTemplateDecl
5120  // for a TUK_Friend.
5121  Declarator TheDeclarator(DS, Declarator::MemberContext);
5122  QualType T = GetTypeForDeclarator(TheDeclarator, S);
5123  if (TheDeclarator.isInvalidType())
5124    return DeclPtrTy();
5125
5126  // This is definitely an error in C++98.  It's probably meant to
5127  // be forbidden in C++0x, too, but the specification is just
5128  // poorly written.
5129  //
5130  // The problem is with declarations like the following:
5131  //   template <T> friend A<T>::foo;
5132  // where deciding whether a class C is a friend or not now hinges
5133  // on whether there exists an instantiation of A that causes
5134  // 'foo' to equal C.  There are restrictions on class-heads
5135  // (which we declare (by fiat) elaborated friend declarations to
5136  // be) that makes this tractable.
5137  //
5138  // FIXME: handle "template <> friend class A<T>;", which
5139  // is possibly well-formed?  Who even knows?
5140  if (TempParams.size() && !isa<ElaboratedType>(T)) {
5141    Diag(Loc, diag::err_tagless_friend_type_template)
5142      << DS.getSourceRange();
5143    return DeclPtrTy();
5144  }
5145
5146  // C++ [class.friend]p2:
5147  //   An elaborated-type-specifier shall be used in a friend declaration
5148  //   for a class.*
5149  //   * The class-key of the elaborated-type-specifier is required.
5150  // This is one of the rare places in Clang where it's legitimate to
5151  // ask about the "spelling" of the type.
5152  if (!getLangOptions().CPlusPlus0x && !isa<ElaboratedType>(T)) {
5153    // If we evaluated the type to a record type, suggest putting
5154    // a tag in front.
5155    if (const RecordType *RT = T->getAs<RecordType>()) {
5156      RecordDecl *RD = RT->getDecl();
5157
5158      std::string InsertionText = std::string(" ") + RD->getKindName();
5159
5160      Diag(DS.getTypeSpecTypeLoc(), diag::err_unelaborated_friend_type)
5161        << (unsigned) RD->getTagKind()
5162        << T
5163        << SourceRange(DS.getFriendSpecLoc())
5164        << CodeModificationHint::CreateInsertion(DS.getTypeSpecTypeLoc(),
5165                                                 InsertionText);
5166      return DeclPtrTy();
5167    }else {
5168      Diag(DS.getFriendSpecLoc(), diag::err_unexpected_friend)
5169          << DS.getSourceRange();
5170      return DeclPtrTy();
5171    }
5172  }
5173
5174  // Enum types cannot be friends.
5175  if (T->getAs<EnumType>()) {
5176    Diag(DS.getTypeSpecTypeLoc(), diag::err_enum_friend)
5177      << SourceRange(DS.getFriendSpecLoc());
5178    return DeclPtrTy();
5179  }
5180
5181  // C++98 [class.friend]p1: A friend of a class is a function
5182  //   or class that is not a member of the class . . .
5183  // But that's a silly restriction which nobody implements for
5184  // inner classes, and C++0x removes it anyway, so we only report
5185  // this (as a warning) if we're being pedantic.
5186  if (!getLangOptions().CPlusPlus0x)
5187    if (const RecordType *RT = T->getAs<RecordType>())
5188      if (RT->getDecl()->getDeclContext() == CurContext)
5189        Diag(DS.getFriendSpecLoc(), diag::ext_friend_inner_class);
5190
5191  Decl *D;
5192  if (TempParams.size())
5193    D = FriendTemplateDecl::Create(Context, CurContext, Loc,
5194                                   TempParams.size(),
5195                                 (TemplateParameterList**) TempParams.release(),
5196                                   T.getTypePtr(),
5197                                   DS.getFriendSpecLoc());
5198  else
5199    D = FriendDecl::Create(Context, CurContext, Loc, T.getTypePtr(),
5200                           DS.getFriendSpecLoc());
5201  D->setAccess(AS_public);
5202  CurContext->addDecl(D);
5203
5204  return DeclPtrTy::make(D);
5205}
5206
5207Sema::DeclPtrTy
5208Sema::ActOnFriendFunctionDecl(Scope *S,
5209                              Declarator &D,
5210                              bool IsDefinition,
5211                              MultiTemplateParamsArg TemplateParams) {
5212  const DeclSpec &DS = D.getDeclSpec();
5213
5214  assert(DS.isFriendSpecified());
5215  assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
5216
5217  SourceLocation Loc = D.getIdentifierLoc();
5218  TypeSourceInfo *TInfo = 0;
5219  QualType T = GetTypeForDeclarator(D, S, &TInfo);
5220
5221  // C++ [class.friend]p1
5222  //   A friend of a class is a function or class....
5223  // Note that this sees through typedefs, which is intended.
5224  // It *doesn't* see through dependent types, which is correct
5225  // according to [temp.arg.type]p3:
5226  //   If a declaration acquires a function type through a
5227  //   type dependent on a template-parameter and this causes
5228  //   a declaration that does not use the syntactic form of a
5229  //   function declarator to have a function type, the program
5230  //   is ill-formed.
5231  if (!T->isFunctionType()) {
5232    Diag(Loc, diag::err_unexpected_friend);
5233
5234    // It might be worthwhile to try to recover by creating an
5235    // appropriate declaration.
5236    return DeclPtrTy();
5237  }
5238
5239  // C++ [namespace.memdef]p3
5240  //  - If a friend declaration in a non-local class first declares a
5241  //    class or function, the friend class or function is a member
5242  //    of the innermost enclosing namespace.
5243  //  - The name of the friend is not found by simple name lookup
5244  //    until a matching declaration is provided in that namespace
5245  //    scope (either before or after the class declaration granting
5246  //    friendship).
5247  //  - If a friend function is called, its name may be found by the
5248  //    name lookup that considers functions from namespaces and
5249  //    classes associated with the types of the function arguments.
5250  //  - When looking for a prior declaration of a class or a function
5251  //    declared as a friend, scopes outside the innermost enclosing
5252  //    namespace scope are not considered.
5253
5254  CXXScopeSpec &ScopeQual = D.getCXXScopeSpec();
5255  DeclarationName Name = GetNameForDeclarator(D);
5256  assert(Name);
5257
5258  // The context we found the declaration in, or in which we should
5259  // create the declaration.
5260  DeclContext *DC;
5261
5262  // FIXME: handle local classes
5263
5264  // Recover from invalid scope qualifiers as if they just weren't there.
5265  LookupResult Previous(*this, Name, D.getIdentifierLoc(), LookupOrdinaryName,
5266                        ForRedeclaration);
5267  if (!ScopeQual.isInvalid() && ScopeQual.isSet()) {
5268    // FIXME: RequireCompleteDeclContext
5269    DC = computeDeclContext(ScopeQual);
5270
5271    // FIXME: handle dependent contexts
5272    if (!DC) return DeclPtrTy();
5273
5274    LookupQualifiedName(Previous, DC);
5275
5276    // If searching in that context implicitly found a declaration in
5277    // a different context, treat it like it wasn't found at all.
5278    // TODO: better diagnostics for this case.  Suggesting the right
5279    // qualified scope would be nice...
5280    // FIXME: getRepresentativeDecl() is not right here at all
5281    if (Previous.empty() ||
5282        !Previous.getRepresentativeDecl()->getDeclContext()->Equals(DC)) {
5283      D.setInvalidType();
5284      Diag(Loc, diag::err_qualified_friend_not_found) << Name << T;
5285      return DeclPtrTy();
5286    }
5287
5288    // C++ [class.friend]p1: A friend of a class is a function or
5289    //   class that is not a member of the class . . .
5290    if (DC->Equals(CurContext))
5291      Diag(DS.getFriendSpecLoc(), diag::err_friend_is_member);
5292
5293  // Otherwise walk out to the nearest namespace scope looking for matches.
5294  } else {
5295    // TODO: handle local class contexts.
5296
5297    DC = CurContext;
5298    while (true) {
5299      // Skip class contexts.  If someone can cite chapter and verse
5300      // for this behavior, that would be nice --- it's what GCC and
5301      // EDG do, and it seems like a reasonable intent, but the spec
5302      // really only says that checks for unqualified existing
5303      // declarations should stop at the nearest enclosing namespace,
5304      // not that they should only consider the nearest enclosing
5305      // namespace.
5306      while (DC->isRecord())
5307        DC = DC->getParent();
5308
5309      LookupQualifiedName(Previous, DC);
5310
5311      // TODO: decide what we think about using declarations.
5312      if (!Previous.empty())
5313        break;
5314
5315      if (DC->isFileContext()) break;
5316      DC = DC->getParent();
5317    }
5318
5319    // C++ [class.friend]p1: A friend of a class is a function or
5320    //   class that is not a member of the class . . .
5321    // C++0x changes this for both friend types and functions.
5322    // Most C++ 98 compilers do seem to give an error here, so
5323    // we do, too.
5324    if (!Previous.empty() && DC->Equals(CurContext)
5325        && !getLangOptions().CPlusPlus0x)
5326      Diag(DS.getFriendSpecLoc(), diag::err_friend_is_member);
5327  }
5328
5329  if (DC->isFileContext()) {
5330    // This implies that it has to be an operator or function.
5331    if (D.getName().getKind() == UnqualifiedId::IK_ConstructorName ||
5332        D.getName().getKind() == UnqualifiedId::IK_DestructorName ||
5333        D.getName().getKind() == UnqualifiedId::IK_ConversionFunctionId) {
5334      Diag(Loc, diag::err_introducing_special_friend) <<
5335        (D.getName().getKind() == UnqualifiedId::IK_ConstructorName ? 0 :
5336         D.getName().getKind() == UnqualifiedId::IK_DestructorName ? 1 : 2);
5337      return DeclPtrTy();
5338    }
5339  }
5340
5341  bool Redeclaration = false;
5342  NamedDecl *ND = ActOnFunctionDeclarator(S, D, DC, T, TInfo, Previous,
5343                                          move(TemplateParams),
5344                                          IsDefinition,
5345                                          Redeclaration);
5346  if (!ND) return DeclPtrTy();
5347
5348  assert(ND->getDeclContext() == DC);
5349  assert(ND->getLexicalDeclContext() == CurContext);
5350
5351  // Add the function declaration to the appropriate lookup tables,
5352  // adjusting the redeclarations list as necessary.  We don't
5353  // want to do this yet if the friending class is dependent.
5354  //
5355  // Also update the scope-based lookup if the target context's
5356  // lookup context is in lexical scope.
5357  if (!CurContext->isDependentContext()) {
5358    DC = DC->getLookupContext();
5359    DC->makeDeclVisibleInContext(ND, /* Recoverable=*/ false);
5360    if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
5361      PushOnScopeChains(ND, EnclosingScope, /*AddToContext=*/ false);
5362  }
5363
5364  FriendDecl *FrD = FriendDecl::Create(Context, CurContext,
5365                                       D.getIdentifierLoc(), ND,
5366                                       DS.getFriendSpecLoc());
5367  FrD->setAccess(AS_public);
5368  CurContext->addDecl(FrD);
5369
5370  return DeclPtrTy::make(ND);
5371}
5372
5373void Sema::SetDeclDeleted(DeclPtrTy dcl, SourceLocation DelLoc) {
5374  AdjustDeclIfTemplate(dcl);
5375
5376  Decl *Dcl = dcl.getAs<Decl>();
5377  FunctionDecl *Fn = dyn_cast<FunctionDecl>(Dcl);
5378  if (!Fn) {
5379    Diag(DelLoc, diag::err_deleted_non_function);
5380    return;
5381  }
5382  if (const FunctionDecl *Prev = Fn->getPreviousDeclaration()) {
5383    Diag(DelLoc, diag::err_deleted_decl_not_first);
5384    Diag(Prev->getLocation(), diag::note_previous_declaration);
5385    // If the declaration wasn't the first, we delete the function anyway for
5386    // recovery.
5387  }
5388  Fn->setDeleted();
5389}
5390
5391static void SearchForReturnInStmt(Sema &Self, Stmt *S) {
5392  for (Stmt::child_iterator CI = S->child_begin(), E = S->child_end(); CI != E;
5393       ++CI) {
5394    Stmt *SubStmt = *CI;
5395    if (!SubStmt)
5396      continue;
5397    if (isa<ReturnStmt>(SubStmt))
5398      Self.Diag(SubStmt->getSourceRange().getBegin(),
5399           diag::err_return_in_constructor_handler);
5400    if (!isa<Expr>(SubStmt))
5401      SearchForReturnInStmt(Self, SubStmt);
5402  }
5403}
5404
5405void Sema::DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock) {
5406  for (unsigned I = 0, E = TryBlock->getNumHandlers(); I != E; ++I) {
5407    CXXCatchStmt *Handler = TryBlock->getHandler(I);
5408    SearchForReturnInStmt(*this, Handler);
5409  }
5410}
5411
5412bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
5413                                             const CXXMethodDecl *Old) {
5414  QualType NewTy = New->getType()->getAs<FunctionType>()->getResultType();
5415  QualType OldTy = Old->getType()->getAs<FunctionType>()->getResultType();
5416
5417  QualType CNewTy = Context.getCanonicalType(NewTy);
5418  QualType COldTy = Context.getCanonicalType(OldTy);
5419
5420  if (CNewTy == COldTy &&
5421      CNewTy.getLocalCVRQualifiers() == COldTy.getLocalCVRQualifiers())
5422    return false;
5423
5424  // Check if the return types are covariant
5425  QualType NewClassTy, OldClassTy;
5426
5427  /// Both types must be pointers or references to classes.
5428  if (PointerType *NewPT = dyn_cast<PointerType>(NewTy)) {
5429    if (PointerType *OldPT = dyn_cast<PointerType>(OldTy)) {
5430      NewClassTy = NewPT->getPointeeType();
5431      OldClassTy = OldPT->getPointeeType();
5432    }
5433  } else if (ReferenceType *NewRT = dyn_cast<ReferenceType>(NewTy)) {
5434    if (ReferenceType *OldRT = dyn_cast<ReferenceType>(OldTy)) {
5435      NewClassTy = NewRT->getPointeeType();
5436      OldClassTy = OldRT->getPointeeType();
5437    }
5438  }
5439
5440  // The return types aren't either both pointers or references to a class type.
5441  if (NewClassTy.isNull()) {
5442    Diag(New->getLocation(),
5443         diag::err_different_return_type_for_overriding_virtual_function)
5444      << New->getDeclName() << NewTy << OldTy;
5445    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
5446
5447    return true;
5448  }
5449
5450  if (!Context.hasSameUnqualifiedType(NewClassTy, OldClassTy)) {
5451    // Check if the new class derives from the old class.
5452    if (!IsDerivedFrom(NewClassTy, OldClassTy)) {
5453      Diag(New->getLocation(),
5454           diag::err_covariant_return_not_derived)
5455      << New->getDeclName() << NewTy << OldTy;
5456      Diag(Old->getLocation(), diag::note_overridden_virtual_function);
5457      return true;
5458    }
5459
5460    // Check if we the conversion from derived to base is valid.
5461    if (CheckDerivedToBaseConversion(NewClassTy, OldClassTy,
5462                      diag::err_covariant_return_inaccessible_base,
5463                      diag::err_covariant_return_ambiguous_derived_to_base_conv,
5464                      // FIXME: Should this point to the return type?
5465                      New->getLocation(), SourceRange(), New->getDeclName())) {
5466      Diag(Old->getLocation(), diag::note_overridden_virtual_function);
5467      return true;
5468    }
5469  }
5470
5471  // The qualifiers of the return types must be the same.
5472  if (CNewTy.getLocalCVRQualifiers() != COldTy.getLocalCVRQualifiers()) {
5473    Diag(New->getLocation(),
5474         diag::err_covariant_return_type_different_qualifications)
5475    << New->getDeclName() << NewTy << OldTy;
5476    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
5477    return true;
5478  };
5479
5480
5481  // The new class type must have the same or less qualifiers as the old type.
5482  if (NewClassTy.isMoreQualifiedThan(OldClassTy)) {
5483    Diag(New->getLocation(),
5484         diag::err_covariant_return_type_class_type_more_qualified)
5485    << New->getDeclName() << NewTy << OldTy;
5486    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
5487    return true;
5488  };
5489
5490  return false;
5491}
5492
5493bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
5494                                             const CXXMethodDecl *Old)
5495{
5496  if (Old->hasAttr<FinalAttr>()) {
5497    Diag(New->getLocation(), diag::err_final_function_overridden)
5498      << New->getDeclName();
5499    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
5500    return true;
5501  }
5502
5503  return false;
5504}
5505
5506/// \brief Mark the given method pure.
5507///
5508/// \param Method the method to be marked pure.
5509///
5510/// \param InitRange the source range that covers the "0" initializer.
5511bool Sema::CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange) {
5512  if (Method->isVirtual() || Method->getParent()->isDependentContext()) {
5513    Method->setPure();
5514
5515    // A class is abstract if at least one function is pure virtual.
5516    Method->getParent()->setAbstract(true);
5517    return false;
5518  }
5519
5520  if (!Method->isInvalidDecl())
5521    Diag(Method->getLocation(), diag::err_non_virtual_pure)
5522      << Method->getDeclName() << InitRange;
5523  return true;
5524}
5525
5526/// ActOnCXXEnterDeclInitializer - Invoked when we are about to parse an
5527/// initializer for the declaration 'Dcl'.
5528/// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
5529/// static data member of class X, names should be looked up in the scope of
5530/// class X.
5531void Sema::ActOnCXXEnterDeclInitializer(Scope *S, DeclPtrTy Dcl) {
5532  AdjustDeclIfTemplate(Dcl);
5533
5534  Decl *D = Dcl.getAs<Decl>();
5535  // If there is no declaration, there was an error parsing it.
5536  if (D == 0)
5537    return;
5538
5539  // Check whether it is a declaration with a nested name specifier like
5540  // int foo::bar;
5541  if (!D->isOutOfLine())
5542    return;
5543
5544  // C++ [basic.lookup.unqual]p13
5545  //
5546  // A name used in the definition of a static data member of class X
5547  // (after the qualified-id of the static member) is looked up as if the name
5548  // was used in a member function of X.
5549
5550  // Change current context into the context of the initializing declaration.
5551  EnterDeclaratorContext(S, D->getDeclContext());
5552}
5553
5554/// ActOnCXXExitDeclInitializer - Invoked after we are finished parsing an
5555/// initializer for the declaration 'Dcl'.
5556void Sema::ActOnCXXExitDeclInitializer(Scope *S, DeclPtrTy Dcl) {
5557  AdjustDeclIfTemplate(Dcl);
5558
5559  Decl *D = Dcl.getAs<Decl>();
5560  // If there is no declaration, there was an error parsing it.
5561  if (D == 0)
5562    return;
5563
5564  // Check whether it is a declaration with a nested name specifier like
5565  // int foo::bar;
5566  if (!D->isOutOfLine())
5567    return;
5568
5569  assert(S->getEntity() == D->getDeclContext() && "Context imbalance!");
5570  ExitDeclaratorContext(S);
5571}
5572
5573/// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a
5574/// C++ if/switch/while/for statement.
5575/// e.g: "if (int x = f()) {...}"
5576Action::DeclResult
5577Sema::ActOnCXXConditionDeclaration(Scope *S, Declarator &D) {
5578  // C++ 6.4p2:
5579  // The declarator shall not specify a function or an array.
5580  // The type-specifier-seq shall not contain typedef and shall not declare a
5581  // new class or enumeration.
5582  assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
5583         "Parser allowed 'typedef' as storage class of condition decl.");
5584
5585  TypeSourceInfo *TInfo = 0;
5586  TagDecl *OwnedTag = 0;
5587  QualType Ty = GetTypeForDeclarator(D, S, &TInfo, &OwnedTag);
5588
5589  if (Ty->isFunctionType()) { // The declarator shall not specify a function...
5590                              // We exit without creating a CXXConditionDeclExpr because a FunctionDecl
5591                              // would be created and CXXConditionDeclExpr wants a VarDecl.
5592    Diag(D.getIdentifierLoc(), diag::err_invalid_use_of_function_type)
5593      << D.getSourceRange();
5594    return DeclResult();
5595  } else if (OwnedTag && OwnedTag->isDefinition()) {
5596    // The type-specifier-seq shall not declare a new class or enumeration.
5597    Diag(OwnedTag->getLocation(), diag::err_type_defined_in_condition);
5598  }
5599
5600  DeclPtrTy Dcl = ActOnDeclarator(S, D);
5601  if (!Dcl)
5602    return DeclResult();
5603
5604  VarDecl *VD = cast<VarDecl>(Dcl.getAs<Decl>());
5605  VD->setDeclaredInCondition(true);
5606  return Dcl;
5607}
5608
5609void Sema::MaybeMarkVirtualMembersReferenced(SourceLocation Loc,
5610                                             CXXMethodDecl *MD) {
5611  // Ignore dependent types.
5612  if (MD->isDependentContext())
5613    return;
5614
5615  CXXRecordDecl *RD = MD->getParent();
5616
5617  // Ignore classes without a vtable.
5618  if (!RD->isDynamicClass())
5619    return;
5620
5621  if (!MD->isOutOfLine()) {
5622    // The only inline functions we care about are constructors. We also defer
5623    // marking the virtual members as referenced until we've reached the end
5624    // of the translation unit. We do this because we need to know the key
5625    // function of the class in order to determine the key function.
5626    if (isa<CXXConstructorDecl>(MD))
5627      ClassesWithUnmarkedVirtualMembers.insert(std::make_pair(RD, Loc));
5628    return;
5629  }
5630
5631  const CXXMethodDecl *KeyFunction = Context.getKeyFunction(RD);
5632
5633  if (!KeyFunction) {
5634    // This record does not have a key function, so we assume that the vtable
5635    // will be emitted when it's used by the constructor.
5636    if (!isa<CXXConstructorDecl>(MD))
5637      return;
5638  } else if (KeyFunction->getCanonicalDecl() != MD->getCanonicalDecl()) {
5639    // We don't have the right key function.
5640    return;
5641  }
5642
5643  // Mark the members as referenced.
5644  MarkVirtualMembersReferenced(Loc, RD);
5645  ClassesWithUnmarkedVirtualMembers.erase(RD);
5646}
5647
5648bool Sema::ProcessPendingClassesWithUnmarkedVirtualMembers() {
5649  if (ClassesWithUnmarkedVirtualMembers.empty())
5650    return false;
5651
5652  for (std::map<CXXRecordDecl *, SourceLocation>::iterator i =
5653       ClassesWithUnmarkedVirtualMembers.begin(),
5654       e = ClassesWithUnmarkedVirtualMembers.end(); i != e; ++i) {
5655    CXXRecordDecl *RD = i->first;
5656
5657    const CXXMethodDecl *KeyFunction = Context.getKeyFunction(RD);
5658    if (KeyFunction) {
5659      // We know that the class has a key function. If the key function was
5660      // declared in this translation unit, then it the class decl would not
5661      // have been in the ClassesWithUnmarkedVirtualMembers map.
5662      continue;
5663    }
5664
5665    SourceLocation Loc = i->second;
5666    MarkVirtualMembersReferenced(Loc, RD);
5667  }
5668
5669  ClassesWithUnmarkedVirtualMembers.clear();
5670  return true;
5671}
5672
5673void Sema::MarkVirtualMembersReferenced(SourceLocation Loc, CXXRecordDecl *RD) {
5674  for (CXXRecordDecl::method_iterator i = RD->method_begin(),
5675       e = RD->method_end(); i != e; ++i) {
5676    CXXMethodDecl *MD = *i;
5677
5678    // C++ [basic.def.odr]p2:
5679    //   [...] A virtual member function is used if it is not pure. [...]
5680    if (MD->isVirtual() && !MD->isPure())
5681      MarkDeclarationReferenced(Loc, MD);
5682  }
5683}
5684
5685