SemaDeclCXX.cpp revision 5eff73c7679349f39e3602e05fff1ff347a28858
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 "SemaInherit.h"
16#include "clang/AST/ASTConsumer.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/DeclVisitor.h"
19#include "clang/AST/TypeOrdering.h"
20#include "clang/AST/StmtVisitor.h"
21#include "clang/Lex/Preprocessor.h"
22#include "clang/Parse/DeclSpec.h"
23#include "llvm/ADT/STLExtras.h"
24#include "llvm/Support/Compiler.h"
25#include <algorithm> // for std::equal
26#include <map>
27
28using namespace clang;
29
30//===----------------------------------------------------------------------===//
31// CheckDefaultArgumentVisitor
32//===----------------------------------------------------------------------===//
33
34namespace {
35  /// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
36  /// the default argument of a parameter to determine whether it
37  /// contains any ill-formed subexpressions. For example, this will
38  /// diagnose the use of local variables or parameters within the
39  /// default argument expression.
40  class VISIBILITY_HIDDEN CheckDefaultArgumentVisitor
41    : public StmtVisitor<CheckDefaultArgumentVisitor, bool> {
42    Expr *DefaultArg;
43    Sema *S;
44
45  public:
46    CheckDefaultArgumentVisitor(Expr *defarg, Sema *s)
47      : DefaultArg(defarg), S(s) {}
48
49    bool VisitExpr(Expr *Node);
50    bool VisitDeclRefExpr(DeclRefExpr *DRE);
51    bool VisitCXXThisExpr(CXXThisExpr *ThisE);
52  };
53
54  /// VisitExpr - Visit all of the children of this expression.
55  bool CheckDefaultArgumentVisitor::VisitExpr(Expr *Node) {
56    bool IsInvalid = false;
57    for (Stmt::child_iterator I = Node->child_begin(),
58         E = Node->child_end(); I != E; ++I)
59      IsInvalid |= Visit(*I);
60    return IsInvalid;
61  }
62
63  /// VisitDeclRefExpr - Visit a reference to a declaration, to
64  /// determine whether this declaration can be used in the default
65  /// argument expression.
66  bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(DeclRefExpr *DRE) {
67    NamedDecl *Decl = DRE->getDecl();
68    if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Decl)) {
69      // C++ [dcl.fct.default]p9
70      //   Default arguments are evaluated each time the function is
71      //   called. The order of evaluation of function arguments is
72      //   unspecified. Consequently, parameters of a function shall not
73      //   be used in default argument expressions, even if they are not
74      //   evaluated. Parameters of a function declared before a default
75      //   argument expression are in scope and can hide namespace and
76      //   class member names.
77      return S->Diag(DRE->getSourceRange().getBegin(),
78                     diag::err_param_default_argument_references_param)
79         << Param->getDeclName() << DefaultArg->getSourceRange();
80    } else if (VarDecl *VDecl = dyn_cast<VarDecl>(Decl)) {
81      // C++ [dcl.fct.default]p7
82      //   Local variables shall not be used in default argument
83      //   expressions.
84      if (VDecl->isBlockVarDecl())
85        return S->Diag(DRE->getSourceRange().getBegin(),
86                       diag::err_param_default_argument_references_local)
87          << VDecl->getDeclName() << DefaultArg->getSourceRange();
88    }
89
90    return false;
91  }
92
93  /// VisitCXXThisExpr - Visit a C++ "this" expression.
94  bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(CXXThisExpr *ThisE) {
95    // C++ [dcl.fct.default]p8:
96    //   The keyword this shall not be used in a default argument of a
97    //   member function.
98    return S->Diag(ThisE->getSourceRange().getBegin(),
99                   diag::err_param_default_argument_references_this)
100               << ThisE->getSourceRange();
101  }
102}
103
104/// ActOnParamDefaultArgument - Check whether the default argument
105/// provided for a function parameter is well-formed. If so, attach it
106/// to the parameter declaration.
107void
108Sema::ActOnParamDefaultArgument(DeclTy *param, SourceLocation EqualLoc,
109                                ExprArg defarg) {
110  ParmVarDecl *Param = (ParmVarDecl *)param;
111  ExprOwningPtr<Expr> DefaultArg(this, (Expr *)defarg.release());
112  QualType ParamType = Param->getType();
113
114  // Default arguments are only permitted in C++
115  if (!getLangOptions().CPlusPlus) {
116    Diag(EqualLoc, diag::err_param_default_argument)
117      << DefaultArg->getSourceRange();
118    Param->setInvalidDecl();
119    return;
120  }
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  Expr *DefaultArgPtr = DefaultArg.get();
129  bool DefaultInitFailed = CheckInitializerTypes(DefaultArgPtr, ParamType,
130                                                 EqualLoc,
131                                                 Param->getDeclName(),
132                                                 /*DirectInit=*/false);
133  if (DefaultArgPtr != DefaultArg.get()) {
134    DefaultArg.take();
135    DefaultArg.reset(DefaultArgPtr);
136  }
137  if (DefaultInitFailed) {
138    return;
139  }
140
141  // Check that the default argument is well-formed
142  CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg.get(), this);
143  if (DefaultArgChecker.Visit(DefaultArg.get())) {
144    Param->setInvalidDecl();
145    return;
146  }
147
148  // Okay: add the default argument to the parameter
149  Param->setDefaultArg(DefaultArg.take());
150}
151
152/// ActOnParamUnparsedDefaultArgument - We've seen a default
153/// argument for a function parameter, but we can't parse it yet
154/// because we're inside a class definition. Note that this default
155/// argument will be parsed later.
156void Sema::ActOnParamUnparsedDefaultArgument(DeclTy *param,
157                                             SourceLocation EqualLoc) {
158  ParmVarDecl *Param = (ParmVarDecl*)param;
159  if (Param)
160    Param->setUnparsedDefaultArg();
161}
162
163/// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
164/// the default argument for the parameter param failed.
165void Sema::ActOnParamDefaultArgumentError(DeclTy *param) {
166  ((ParmVarDecl*)param)->setInvalidDecl();
167}
168
169/// CheckExtraCXXDefaultArguments - Check for any extra default
170/// arguments in the declarator, which is not a function declaration
171/// or definition and therefore is not permitted to have default
172/// arguments. This routine should be invoked for every declarator
173/// that is not a function declaration or definition.
174void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
175  // C++ [dcl.fct.default]p3
176  //   A default argument expression shall be specified only in the
177  //   parameter-declaration-clause of a function declaration or in a
178  //   template-parameter (14.1). It shall not be specified for a
179  //   parameter pack. If it is specified in a
180  //   parameter-declaration-clause, it shall not occur within a
181  //   declarator or abstract-declarator of a parameter-declaration.
182  for (unsigned i = 0; i < D.getNumTypeObjects(); ++i) {
183    DeclaratorChunk &chunk = D.getTypeObject(i);
184    if (chunk.Kind == DeclaratorChunk::Function) {
185      for (unsigned argIdx = 0; argIdx < chunk.Fun.NumArgs; ++argIdx) {
186        ParmVarDecl *Param = (ParmVarDecl *)chunk.Fun.ArgInfo[argIdx].Param;
187        if (Param->hasUnparsedDefaultArg()) {
188          CachedTokens *Toks = chunk.Fun.ArgInfo[argIdx].DefaultArgTokens;
189          Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
190            << SourceRange((*Toks)[1].getLocation(), Toks->back().getLocation());
191          delete Toks;
192          chunk.Fun.ArgInfo[argIdx].DefaultArgTokens = 0;
193        } else if (Param->getDefaultArg()) {
194          Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
195            << Param->getDefaultArg()->getSourceRange();
196          Param->setDefaultArg(0);
197        }
198      }
199    }
200  }
201}
202
203// MergeCXXFunctionDecl - Merge two declarations of the same C++
204// function, once we already know that they have the same
205// type. Subroutine of MergeFunctionDecl. Returns true if there was an
206// error, false otherwise.
207bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old) {
208  bool Invalid = false;
209
210  // C++ [dcl.fct.default]p4:
211  //
212  //   For non-template functions, default arguments can be added in
213  //   later declarations of a function in the same
214  //   scope. Declarations in different scopes have completely
215  //   distinct sets of default arguments. That is, declarations in
216  //   inner scopes do not acquire default arguments from
217  //   declarations in outer scopes, and vice versa. In a given
218  //   function declaration, all parameters subsequent to a
219  //   parameter with a default argument shall have default
220  //   arguments supplied in this or previous declarations. A
221  //   default argument shall not be redefined by a later
222  //   declaration (not even to the same value).
223  for (unsigned p = 0, NumParams = Old->getNumParams(); p < NumParams; ++p) {
224    ParmVarDecl *OldParam = Old->getParamDecl(p);
225    ParmVarDecl *NewParam = New->getParamDecl(p);
226
227    if(OldParam->getDefaultArg() && NewParam->getDefaultArg()) {
228      Diag(NewParam->getLocation(),
229           diag::err_param_default_argument_redefinition)
230        << NewParam->getDefaultArg()->getSourceRange();
231      Diag(OldParam->getLocation(), diag::note_previous_definition);
232      Invalid = true;
233    } else if (OldParam->getDefaultArg()) {
234      // Merge the old default argument into the new parameter
235      NewParam->setDefaultArg(OldParam->getDefaultArg());
236    }
237  }
238
239  return Invalid;
240}
241
242/// CheckCXXDefaultArguments - Verify that the default arguments for a
243/// function declaration are well-formed according to C++
244/// [dcl.fct.default].
245void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
246  unsigned NumParams = FD->getNumParams();
247  unsigned p;
248
249  // Find first parameter with a default argument
250  for (p = 0; p < NumParams; ++p) {
251    ParmVarDecl *Param = FD->getParamDecl(p);
252    if (Param->getDefaultArg())
253      break;
254  }
255
256  // C++ [dcl.fct.default]p4:
257  //   In a given function declaration, all parameters
258  //   subsequent to a parameter with a default argument shall
259  //   have default arguments supplied in this or previous
260  //   declarations. A default argument shall not be redefined
261  //   by a later declaration (not even to the same value).
262  unsigned LastMissingDefaultArg = 0;
263  for(; p < NumParams; ++p) {
264    ParmVarDecl *Param = FD->getParamDecl(p);
265    if (!Param->getDefaultArg()) {
266      if (Param->isInvalidDecl())
267        /* We already complained about this parameter. */;
268      else if (Param->getIdentifier())
269        Diag(Param->getLocation(),
270             diag::err_param_default_argument_missing_name)
271          << Param->getIdentifier();
272      else
273        Diag(Param->getLocation(),
274             diag::err_param_default_argument_missing);
275
276      LastMissingDefaultArg = p;
277    }
278  }
279
280  if (LastMissingDefaultArg > 0) {
281    // Some default arguments were missing. Clear out all of the
282    // default arguments up to (and including) the last missing
283    // default argument, so that we leave the function parameters
284    // in a semantically valid state.
285    for (p = 0; p <= LastMissingDefaultArg; ++p) {
286      ParmVarDecl *Param = FD->getParamDecl(p);
287      if (Param->getDefaultArg()) {
288        if (!Param->hasUnparsedDefaultArg())
289          Param->getDefaultArg()->Destroy(Context);
290        Param->setDefaultArg(0);
291      }
292    }
293  }
294}
295
296/// isCurrentClassName - Determine whether the identifier II is the
297/// name of the class type currently being defined. In the case of
298/// nested classes, this will only return true if II is the name of
299/// the innermost class.
300bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *,
301                              const CXXScopeSpec *SS) {
302  CXXRecordDecl *CurDecl;
303  if (SS && SS->isSet() && !SS->isInvalid()) {
304    DeclContext *DC = computeDeclContext(*SS);
305    CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
306  } else
307    CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
308
309  if (CurDecl)
310    return &II == CurDecl->getIdentifier();
311  else
312    return false;
313}
314
315/// \brief Check the validity of a C++ base class specifier.
316///
317/// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
318/// and returns NULL otherwise.
319CXXBaseSpecifier *
320Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
321                         SourceRange SpecifierRange,
322                         bool Virtual, AccessSpecifier Access,
323                         QualType BaseType,
324                         SourceLocation BaseLoc) {
325  // C++ [class.union]p1:
326  //   A union shall not have base classes.
327  if (Class->isUnion()) {
328    Diag(Class->getLocation(), diag::err_base_clause_on_union)
329      << SpecifierRange;
330    return 0;
331  }
332
333  if (BaseType->isDependentType())
334    return new CXXBaseSpecifier(SpecifierRange, Virtual,
335                                Class->getTagKind() == RecordDecl::TK_class,
336                                Access, BaseType);
337
338  // Base specifiers must be record types.
339  if (!BaseType->isRecordType()) {
340    Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
341    return 0;
342  }
343
344  // C++ [class.union]p1:
345  //   A union shall not be used as a base class.
346  if (BaseType->isUnionType()) {
347    Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
348    return 0;
349  }
350
351  // C++ [class.derived]p2:
352  //   The class-name in a base-specifier shall not be an incompletely
353  //   defined class.
354  if (RequireCompleteType(BaseLoc, BaseType, diag::err_incomplete_base_class,
355                          SpecifierRange))
356    return 0;
357
358  // If the base class is polymorphic, the new one is, too.
359  RecordDecl *BaseDecl = BaseType->getAsRecordType()->getDecl();
360  assert(BaseDecl && "Record type has no declaration");
361  BaseDecl = BaseDecl->getDefinition(Context);
362  assert(BaseDecl && "Base type is not incomplete, but has no definition");
363  if (cast<CXXRecordDecl>(BaseDecl)->isPolymorphic())
364    Class->setPolymorphic(true);
365
366  // C++ [dcl.init.aggr]p1:
367  //   An aggregate is [...] a class with [...] no base classes [...].
368  Class->setAggregate(false);
369  Class->setPOD(false);
370
371  // Create the base specifier.
372  // FIXME: Allocate via ASTContext?
373  return new CXXBaseSpecifier(SpecifierRange, Virtual,
374                              Class->getTagKind() == RecordDecl::TK_class,
375                              Access, BaseType);
376}
377
378/// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
379/// one entry in the base class list of a class specifier, for
380/// example:
381///    class foo : public bar, virtual private baz {
382/// 'public bar' and 'virtual private baz' are each base-specifiers.
383Sema::BaseResult
384Sema::ActOnBaseSpecifier(DeclTy *classdecl, SourceRange SpecifierRange,
385                         bool Virtual, AccessSpecifier Access,
386                         TypeTy *basetype, SourceLocation BaseLoc) {
387  AdjustDeclIfTemplate(classdecl);
388  CXXRecordDecl *Class = cast<CXXRecordDecl>((Decl*)classdecl);
389  QualType BaseType = QualType::getFromOpaquePtr(basetype);
390  if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
391                                                      Virtual, Access,
392                                                      BaseType, BaseLoc))
393    return BaseSpec;
394
395  return true;
396}
397
398/// \brief Performs the actual work of attaching the given base class
399/// specifiers to a C++ class.
400bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class, CXXBaseSpecifier **Bases,
401                                unsigned NumBases) {
402 if (NumBases == 0)
403    return false;
404
405  // Used to keep track of which base types we have already seen, so
406  // that we can properly diagnose redundant direct base types. Note
407  // that the key is always the unqualified canonical type of the base
408  // class.
409  std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
410
411  // Copy non-redundant base specifiers into permanent storage.
412  unsigned NumGoodBases = 0;
413  bool Invalid = false;
414  for (unsigned idx = 0; idx < NumBases; ++idx) {
415    QualType NewBaseType
416      = Context.getCanonicalType(Bases[idx]->getType());
417    NewBaseType = NewBaseType.getUnqualifiedType();
418
419    if (KnownBaseTypes[NewBaseType]) {
420      // C++ [class.mi]p3:
421      //   A class shall not be specified as a direct base class of a
422      //   derived class more than once.
423      Diag(Bases[idx]->getSourceRange().getBegin(),
424           diag::err_duplicate_base_class)
425        << KnownBaseTypes[NewBaseType]->getType()
426        << Bases[idx]->getSourceRange();
427
428      // Delete the duplicate base class specifier; we're going to
429      // overwrite its pointer later.
430      delete Bases[idx];
431
432      Invalid = true;
433    } else {
434      // Okay, add this new base class.
435      KnownBaseTypes[NewBaseType] = Bases[idx];
436      Bases[NumGoodBases++] = Bases[idx];
437    }
438  }
439
440  // Attach the remaining base class specifiers to the derived class.
441  Class->setBases(Bases, NumGoodBases);
442
443  // Delete the remaining (good) base class specifiers, since their
444  // data has been copied into the CXXRecordDecl.
445  for (unsigned idx = 0; idx < NumGoodBases; ++idx)
446    delete Bases[idx];
447
448  return Invalid;
449}
450
451/// ActOnBaseSpecifiers - Attach the given base specifiers to the
452/// class, after checking whether there are any duplicate base
453/// classes.
454void Sema::ActOnBaseSpecifiers(DeclTy *ClassDecl, BaseTy **Bases,
455                               unsigned NumBases) {
456  if (!ClassDecl || !Bases || !NumBases)
457    return;
458
459  AdjustDeclIfTemplate(ClassDecl);
460  AttachBaseSpecifiers(cast<CXXRecordDecl>((Decl*)ClassDecl),
461                       (CXXBaseSpecifier**)(Bases), NumBases);
462}
463
464//===----------------------------------------------------------------------===//
465// C++ class member Handling
466//===----------------------------------------------------------------------===//
467
468/// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
469/// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
470/// bitfield width if there is one and 'InitExpr' specifies the initializer if
471/// any. 'LastInGroup' is non-null for cases where one declspec has multiple
472/// declarators on it.
473Sema::DeclTy *
474Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
475                               ExprTy *BW, ExprTy *InitExpr,
476                               DeclTy *LastInGroup) {
477  const DeclSpec &DS = D.getDeclSpec();
478  DeclarationName Name = GetNameForDeclarator(D);
479  Expr *BitWidth = static_cast<Expr*>(BW);
480  Expr *Init = static_cast<Expr*>(InitExpr);
481  SourceLocation Loc = D.getIdentifierLoc();
482
483  bool isFunc = D.isFunctionDeclarator();
484
485  // C++ 9.2p6: A member shall not be declared to have automatic storage
486  // duration (auto, register) or with the extern storage-class-specifier.
487  // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
488  // data members and cannot be applied to names declared const or static,
489  // and cannot be applied to reference members.
490  switch (DS.getStorageClassSpec()) {
491    case DeclSpec::SCS_unspecified:
492    case DeclSpec::SCS_typedef:
493    case DeclSpec::SCS_static:
494      // FALL THROUGH.
495      break;
496    case DeclSpec::SCS_mutable:
497      if (isFunc) {
498        if (DS.getStorageClassSpecLoc().isValid())
499          Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
500        else
501          Diag(DS.getThreadSpecLoc(), diag::err_mutable_function);
502
503        // FIXME: It would be nicer if the keyword was ignored only for this
504        // declarator. Otherwise we could get follow-up errors.
505        D.getMutableDeclSpec().ClearStorageClassSpecs();
506      } else {
507        QualType T = GetTypeForDeclarator(D, S);
508        diag::kind err = static_cast<diag::kind>(0);
509        if (T->isReferenceType())
510          err = diag::err_mutable_reference;
511        else if (T.isConstQualified())
512          err = diag::err_mutable_const;
513        if (err != 0) {
514          if (DS.getStorageClassSpecLoc().isValid())
515            Diag(DS.getStorageClassSpecLoc(), err);
516          else
517            Diag(DS.getThreadSpecLoc(), err);
518          // FIXME: It would be nicer if the keyword was ignored only for this
519          // declarator. Otherwise we could get follow-up errors.
520          D.getMutableDeclSpec().ClearStorageClassSpecs();
521        }
522      }
523      break;
524    default:
525      if (DS.getStorageClassSpecLoc().isValid())
526        Diag(DS.getStorageClassSpecLoc(),
527             diag::err_storageclass_invalid_for_member);
528      else
529        Diag(DS.getThreadSpecLoc(), diag::err_storageclass_invalid_for_member);
530      D.getMutableDeclSpec().ClearStorageClassSpecs();
531  }
532
533  if (!isFunc &&
534      D.getDeclSpec().getTypeSpecType() == DeclSpec::TST_typename &&
535      D.getNumTypeObjects() == 0) {
536    // Check also for this case:
537    //
538    // typedef int f();
539    // f a;
540    //
541    QualType TDType = QualType::getFromOpaquePtr(DS.getTypeRep());
542    isFunc = TDType->isFunctionType();
543  }
544
545  bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
546                       DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
547                      !isFunc);
548
549  Decl *Member;
550  if (isInstField) {
551    Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D, BitWidth,
552                         AS);
553    assert(Member && "HandleField never returns null");
554  } else {
555    Member = static_cast<Decl*>(ActOnDeclarator(S, D, LastInGroup));
556    if (!Member) {
557      if (BitWidth) DeleteExpr(BitWidth);
558      return LastInGroup;
559    }
560
561    // Non-instance-fields can't have a bitfield.
562    if (BitWidth) {
563      if (Member->isInvalidDecl()) {
564        // don't emit another diagnostic.
565      } else if (isa<VarDecl>(Member)) {
566        // C++ 9.6p3: A bit-field shall not be a static member.
567        // "static member 'A' cannot be a bit-field"
568        Diag(Loc, diag::err_static_not_bitfield)
569          << Name << BitWidth->getSourceRange();
570      } else if (isa<TypedefDecl>(Member)) {
571        // "typedef member 'x' cannot be a bit-field"
572        Diag(Loc, diag::err_typedef_not_bitfield)
573          << Name << BitWidth->getSourceRange();
574      } else {
575        // A function typedef ("typedef int f(); f a;").
576        // C++ 9.6p3: A bit-field shall have integral or enumeration type.
577        Diag(Loc, diag::err_not_integral_type_bitfield)
578          << Name << cast<ValueDecl>(Member)->getType()
579          << BitWidth->getSourceRange();
580      }
581
582      DeleteExpr(BitWidth);
583      BitWidth = 0;
584      Member->setInvalidDecl();
585    }
586
587    Member->setAccess(AS);
588  }
589
590  assert((Name || isInstField) && "No identifier for non-field ?");
591
592  if (Init)
593    AddInitializerToDecl(Member, ExprArg(*this, Init), false);
594
595  if (isInstField) {
596    FieldCollector->Add(cast<FieldDecl>(Member));
597    return LastInGroup;
598  }
599  return Member;
600}
601
602/// ActOnMemInitializer - Handle a C++ member initializer.
603Sema::MemInitResult
604Sema::ActOnMemInitializer(DeclTy *ConstructorD,
605                          Scope *S,
606                          IdentifierInfo *MemberOrBase,
607                          SourceLocation IdLoc,
608                          SourceLocation LParenLoc,
609                          ExprTy **Args, unsigned NumArgs,
610                          SourceLocation *CommaLocs,
611                          SourceLocation RParenLoc) {
612  CXXConstructorDecl *Constructor
613    = dyn_cast<CXXConstructorDecl>((Decl*)ConstructorD);
614  if (!Constructor) {
615    // The user wrote a constructor initializer on a function that is
616    // not a C++ constructor. Ignore the error for now, because we may
617    // have more member initializers coming; we'll diagnose it just
618    // once in ActOnMemInitializers.
619    return true;
620  }
621
622  CXXRecordDecl *ClassDecl = Constructor->getParent();
623
624  // C++ [class.base.init]p2:
625  //   Names in a mem-initializer-id are looked up in the scope of the
626  //   constructor’s class and, if not found in that scope, are looked
627  //   up in the scope containing the constructor’s
628  //   definition. [Note: if the constructor’s class contains a member
629  //   with the same name as a direct or virtual base class of the
630  //   class, a mem-initializer-id naming the member or base class and
631  //   composed of a single identifier refers to the class member. A
632  //   mem-initializer-id for the hidden base class may be specified
633  //   using a qualified name. ]
634  // Look for a member, first.
635  FieldDecl *Member = 0;
636  DeclContext::lookup_result Result = ClassDecl->lookup(MemberOrBase);
637  if (Result.first != Result.second)
638    Member = dyn_cast<FieldDecl>(*Result.first);
639
640  // FIXME: Handle members of an anonymous union.
641
642  if (Member) {
643    // FIXME: Perform direct initialization of the member.
644    return new CXXBaseOrMemberInitializer(Member, (Expr **)Args, NumArgs);
645  }
646
647  // It didn't name a member, so see if it names a class.
648  TypeTy *BaseTy = getTypeName(*MemberOrBase, IdLoc, S, 0/*SS*/);
649  if (!BaseTy)
650    return Diag(IdLoc, diag::err_mem_init_not_member_or_class)
651      << MemberOrBase << SourceRange(IdLoc, RParenLoc);
652
653  QualType BaseType = QualType::getFromOpaquePtr(BaseTy);
654  if (!BaseType->isRecordType())
655    return Diag(IdLoc, diag::err_base_init_does_not_name_class)
656      << BaseType << SourceRange(IdLoc, RParenLoc);
657
658  // C++ [class.base.init]p2:
659  //   [...] Unless the mem-initializer-id names a nonstatic data
660  //   member of the constructor’s class or a direct or virtual base
661  //   of that class, the mem-initializer is ill-formed. A
662  //   mem-initializer-list can initialize a base class using any
663  //   name that denotes that base class type.
664
665  // First, check for a direct base class.
666  const CXXBaseSpecifier *DirectBaseSpec = 0;
667  for (CXXRecordDecl::base_class_const_iterator Base = ClassDecl->bases_begin();
668       Base != ClassDecl->bases_end(); ++Base) {
669    if (Context.getCanonicalType(BaseType).getUnqualifiedType() ==
670        Context.getCanonicalType(Base->getType()).getUnqualifiedType()) {
671      // We found a direct base of this type. That's what we're
672      // initializing.
673      DirectBaseSpec = &*Base;
674      break;
675    }
676  }
677
678  // Check for a virtual base class.
679  // FIXME: We might be able to short-circuit this if we know in
680  // advance that there are no virtual bases.
681  const CXXBaseSpecifier *VirtualBaseSpec = 0;
682  if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
683    // We haven't found a base yet; search the class hierarchy for a
684    // virtual base class.
685    BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
686                    /*DetectVirtual=*/false);
687    if (IsDerivedFrom(Context.getTypeDeclType(ClassDecl), BaseType, Paths)) {
688      for (BasePaths::paths_iterator Path = Paths.begin();
689           Path != Paths.end(); ++Path) {
690        if (Path->back().Base->isVirtual()) {
691          VirtualBaseSpec = Path->back().Base;
692          break;
693        }
694      }
695    }
696  }
697
698  // C++ [base.class.init]p2:
699  //   If a mem-initializer-id is ambiguous because it designates both
700  //   a direct non-virtual base class and an inherited virtual base
701  //   class, the mem-initializer is ill-formed.
702  if (DirectBaseSpec && VirtualBaseSpec)
703    return Diag(IdLoc, diag::err_base_init_direct_and_virtual)
704      << MemberOrBase << SourceRange(IdLoc, RParenLoc);
705
706  return new CXXBaseOrMemberInitializer(BaseType, (Expr **)Args, NumArgs);
707}
708
709namespace {
710  /// PureVirtualMethodCollector - traverses a class and its superclasses
711  /// and determines if it has any pure virtual methods.
712  class VISIBILITY_HIDDEN PureVirtualMethodCollector {
713    ASTContext &Context;
714
715  public:
716    typedef llvm::SmallVector<const CXXMethodDecl*, 8> MethodList;
717
718  private:
719    MethodList Methods;
720
721    void Collect(const CXXRecordDecl* RD, MethodList& Methods);
722
723  public:
724    PureVirtualMethodCollector(ASTContext &Ctx, const CXXRecordDecl* RD)
725      : Context(Ctx) {
726
727      MethodList List;
728      Collect(RD, List);
729
730      // Copy the temporary list to methods, and make sure to ignore any
731      // null entries.
732      for (size_t i = 0, e = List.size(); i != e; ++i) {
733        if (List[i])
734          Methods.push_back(List[i]);
735      }
736    }
737
738    bool empty() const { return Methods.empty(); }
739
740    MethodList::const_iterator methods_begin() { return Methods.begin(); }
741    MethodList::const_iterator methods_end() { return Methods.end(); }
742  };
743
744  void PureVirtualMethodCollector::Collect(const CXXRecordDecl* RD,
745                                           MethodList& Methods) {
746    // First, collect the pure virtual methods for the base classes.
747    for (CXXRecordDecl::base_class_const_iterator Base = RD->bases_begin(),
748         BaseEnd = RD->bases_end(); Base != BaseEnd; ++Base) {
749      if (const RecordType *RT = Base->getType()->getAsRecordType()) {
750        const CXXRecordDecl *BaseDecl
751          = cast<CXXRecordDecl>(RT->getDecl());
752        if (BaseDecl && BaseDecl->isAbstract())
753          Collect(BaseDecl, Methods);
754      }
755    }
756
757    // Next, zero out any pure virtual methods that this class overrides.
758    for (size_t i = 0, e = Methods.size(); i != e; ++i) {
759      const CXXMethodDecl *VMD = dyn_cast_or_null<CXXMethodDecl>(Methods[i]);
760      if (!VMD)
761        continue;
762
763      DeclContext::lookup_const_iterator I, E;
764      for (llvm::tie(I, E) = RD->lookup(VMD->getDeclName()); I != E; ++I) {
765        if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(*I)) {
766          if (Context.getCanonicalType(MD->getType()) ==
767              Context.getCanonicalType(VMD->getType())) {
768            // We did find a matching method, which means that this is not a
769            // pure virtual method in the current class. Zero it out.
770            Methods[i] = 0;
771          }
772        }
773      }
774    }
775
776    // Finally, add pure virtual methods from this class.
777    for (RecordDecl::decl_iterator i = RD->decls_begin(), e = RD->decls_end();
778         i != e; ++i) {
779      if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(*i)) {
780        if (MD->isPure())
781          Methods.push_back(MD);
782      }
783    }
784  }
785}
786
787bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
788                                  unsigned DiagID, AbstractDiagSelID SelID) {
789
790  if (!getLangOptions().CPlusPlus)
791    return false;
792
793  if (const ArrayType *AT = Context.getAsArrayType(T))
794    return RequireNonAbstractType(Loc, AT->getElementType(), DiagID, SelID);
795
796  if (const PointerType *PT = T->getAsPointerType()) {
797    // Find the innermost pointer type.
798    while (const PointerType *T = PT->getPointeeType()->getAsPointerType())
799      PT = T;
800
801    if (const ArrayType *AT = Context.getAsArrayType(PT->getPointeeType()))
802      return RequireNonAbstractType(Loc, AT->getElementType(), DiagID, SelID);
803  }
804
805  const RecordType *RT = T->getAsRecordType();
806  if (!RT)
807    return false;
808
809  const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl());
810  if (!RD)
811    return false;
812
813  if (!RD->isAbstract())
814    return false;
815
816  Diag(Loc, DiagID) << RD->getDeclName() << SelID;
817
818  // Check if we've already emitted the list of pure virtual functions for this
819  // class.
820  if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
821    return true;
822
823  PureVirtualMethodCollector Collector(Context, RD);
824
825  for (PureVirtualMethodCollector::MethodList::const_iterator I =
826       Collector.methods_begin(), E = Collector.methods_end(); I != E; ++I) {
827    const CXXMethodDecl *MD = *I;
828
829    Diag(MD->getLocation(), diag::note_pure_virtual_function) <<
830      MD->getDeclName();
831  }
832
833  if (!PureVirtualClassDiagSet)
834    PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
835  PureVirtualClassDiagSet->insert(RD);
836
837  return true;
838}
839
840namespace {
841  class VISIBILITY_HIDDEN AbstractClassUsageDiagnoser
842    : public DeclVisitor<AbstractClassUsageDiagnoser, bool> {
843    Sema &SemaRef;
844    CXXRecordDecl *AbstractClass;
845
846  public:
847    AbstractClassUsageDiagnoser(Sema& SemaRef, CXXRecordDecl *ac)
848      : SemaRef(SemaRef), AbstractClass(ac) {}
849
850    bool VisitCXXRecordDecl(const CXXRecordDecl *RD) {
851      bool Invalid = false;
852
853      for (CXXRecordDecl::decl_iterator I = RD->decls_begin(),
854           E = RD->decls_end(); I != E; ++I)
855        Invalid |= Visit(*I);
856
857      return Invalid;
858    }
859
860    bool VisitCXXMethodDecl(const CXXMethodDecl *MD) {
861      // Check the return type.
862      QualType RTy = MD->getType()->getAsFunctionType()->getResultType();
863      bool Invalid =
864        SemaRef.RequireNonAbstractType(MD->getLocation(), RTy,
865                                       diag::err_abstract_type_in_decl,
866                                       Sema::AbstractReturnType);
867
868      for (CXXMethodDecl::param_const_iterator I = MD->param_begin(),
869           E = MD->param_end(); I != E; ++I) {
870        const ParmVarDecl *VD = *I;
871        Invalid |=
872          SemaRef.RequireNonAbstractType(VD->getLocation(),
873                                         VD->getOriginalType(),
874                                         diag::err_abstract_type_in_decl,
875                                         Sema::AbstractParamType);
876      }
877
878      return Invalid;
879    }
880  };
881}
882
883void Sema::ActOnFinishCXXMemberSpecification(Scope* S, SourceLocation RLoc,
884                                             DeclTy *TagDecl,
885                                             SourceLocation LBrac,
886                                             SourceLocation RBrac) {
887  TemplateDecl *Template = AdjustDeclIfTemplate(TagDecl);
888  ActOnFields(S, RLoc, TagDecl,
889              (DeclTy**)FieldCollector->getCurFields(),
890              FieldCollector->getCurNumFields(), LBrac, RBrac, 0);
891
892  CXXRecordDecl *RD = cast<CXXRecordDecl>((Decl*)TagDecl);
893  if (!RD->isAbstract()) {
894    // Collect all the pure virtual methods and see if this is an abstract
895    // class after all.
896    PureVirtualMethodCollector Collector(Context, RD);
897    if (!Collector.empty())
898      RD->setAbstract(true);
899  }
900
901  if (RD->isAbstract())
902    AbstractClassUsageDiagnoser(*this, RD).Visit(RD);
903
904  if (!Template)
905    AddImplicitlyDeclaredMembersToClass(RD);
906}
907
908/// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared
909/// special functions, such as the default constructor, copy
910/// constructor, or destructor, to the given C++ class (C++
911/// [special]p1).  This routine can only be executed just before the
912/// definition of the class is complete.
913void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) {
914  QualType ClassType = Context.getTypeDeclType(ClassDecl);
915  ClassType = Context.getCanonicalType(ClassType);
916
917  if (!ClassDecl->hasUserDeclaredConstructor()) {
918    // C++ [class.ctor]p5:
919    //   A default constructor for a class X is a constructor of class X
920    //   that can be called without an argument. If there is no
921    //   user-declared constructor for class X, a default constructor is
922    //   implicitly declared. An implicitly-declared default constructor
923    //   is an inline public member of its class.
924    DeclarationName Name
925      = Context.DeclarationNames.getCXXConstructorName(ClassType);
926    CXXConstructorDecl *DefaultCon =
927      CXXConstructorDecl::Create(Context, ClassDecl,
928                                 ClassDecl->getLocation(), Name,
929                                 Context.getFunctionType(Context.VoidTy,
930                                                         0, 0, false, 0),
931                                 /*isExplicit=*/false,
932                                 /*isInline=*/true,
933                                 /*isImplicitlyDeclared=*/true);
934    DefaultCon->setAccess(AS_public);
935    DefaultCon->setImplicit();
936    ClassDecl->addDecl(DefaultCon);
937
938    // Notify the class that we've added a constructor.
939    ClassDecl->addedConstructor(Context, DefaultCon);
940  }
941
942  if (!ClassDecl->hasUserDeclaredCopyConstructor()) {
943    // C++ [class.copy]p4:
944    //   If the class definition does not explicitly declare a copy
945    //   constructor, one is declared implicitly.
946
947    // C++ [class.copy]p5:
948    //   The implicitly-declared copy constructor for a class X will
949    //   have the form
950    //
951    //       X::X(const X&)
952    //
953    //   if
954    bool HasConstCopyConstructor = true;
955
956    //     -- each direct or virtual base class B of X has a copy
957    //        constructor whose first parameter is of type const B& or
958    //        const volatile B&, and
959    for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin();
960         HasConstCopyConstructor && Base != ClassDecl->bases_end(); ++Base) {
961      const CXXRecordDecl *BaseClassDecl
962        = cast<CXXRecordDecl>(Base->getType()->getAsRecordType()->getDecl());
963      HasConstCopyConstructor
964        = BaseClassDecl->hasConstCopyConstructor(Context);
965    }
966
967    //     -- for all the nonstatic data members of X that are of a
968    //        class type M (or array thereof), each such class type
969    //        has a copy constructor whose first parameter is of type
970    //        const M& or const volatile M&.
971    for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin();
972         HasConstCopyConstructor && Field != ClassDecl->field_end(); ++Field) {
973      QualType FieldType = (*Field)->getType();
974      if (const ArrayType *Array = Context.getAsArrayType(FieldType))
975        FieldType = Array->getElementType();
976      if (const RecordType *FieldClassType = FieldType->getAsRecordType()) {
977        const CXXRecordDecl *FieldClassDecl
978          = cast<CXXRecordDecl>(FieldClassType->getDecl());
979        HasConstCopyConstructor
980          = FieldClassDecl->hasConstCopyConstructor(Context);
981      }
982    }
983
984    //   Otherwise, the implicitly declared copy constructor will have
985    //   the form
986    //
987    //       X::X(X&)
988    QualType ArgType = ClassType;
989    if (HasConstCopyConstructor)
990      ArgType = ArgType.withConst();
991    ArgType = Context.getLValueReferenceType(ArgType);
992
993    //   An implicitly-declared copy constructor is an inline public
994    //   member of its class.
995    DeclarationName Name
996      = Context.DeclarationNames.getCXXConstructorName(ClassType);
997    CXXConstructorDecl *CopyConstructor
998      = CXXConstructorDecl::Create(Context, ClassDecl,
999                                   ClassDecl->getLocation(), Name,
1000                                   Context.getFunctionType(Context.VoidTy,
1001                                                           &ArgType, 1,
1002                                                           false, 0),
1003                                   /*isExplicit=*/false,
1004                                   /*isInline=*/true,
1005                                   /*isImplicitlyDeclared=*/true);
1006    CopyConstructor->setAccess(AS_public);
1007    CopyConstructor->setImplicit();
1008
1009    // Add the parameter to the constructor.
1010    ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyConstructor,
1011                                                 ClassDecl->getLocation(),
1012                                                 /*IdentifierInfo=*/0,
1013                                                 ArgType, VarDecl::None, 0);
1014    CopyConstructor->setParams(Context, &FromParam, 1);
1015
1016    ClassDecl->addedConstructor(Context, CopyConstructor);
1017    ClassDecl->addDecl(CopyConstructor);
1018  }
1019
1020  if (!ClassDecl->hasUserDeclaredCopyAssignment()) {
1021    // Note: The following rules are largely analoguous to the copy
1022    // constructor rules. Note that virtual bases are not taken into account
1023    // for determining the argument type of the operator. Note also that
1024    // operators taking an object instead of a reference are allowed.
1025    //
1026    // C++ [class.copy]p10:
1027    //   If the class definition does not explicitly declare a copy
1028    //   assignment operator, one is declared implicitly.
1029    //   The implicitly-defined copy assignment operator for a class X
1030    //   will have the form
1031    //
1032    //       X& X::operator=(const X&)
1033    //
1034    //   if
1035    bool HasConstCopyAssignment = true;
1036
1037    //       -- each direct base class B of X has a copy assignment operator
1038    //          whose parameter is of type const B&, const volatile B& or B,
1039    //          and
1040    for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin();
1041         HasConstCopyAssignment && Base != ClassDecl->bases_end(); ++Base) {
1042      const CXXRecordDecl *BaseClassDecl
1043        = cast<CXXRecordDecl>(Base->getType()->getAsRecordType()->getDecl());
1044      HasConstCopyAssignment = BaseClassDecl->hasConstCopyAssignment(Context);
1045    }
1046
1047    //       -- for all the nonstatic data members of X that are of a class
1048    //          type M (or array thereof), each such class type has a copy
1049    //          assignment operator whose parameter is of type const M&,
1050    //          const volatile M& or M.
1051    for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin();
1052         HasConstCopyAssignment && Field != ClassDecl->field_end(); ++Field) {
1053      QualType FieldType = (*Field)->getType();
1054      if (const ArrayType *Array = Context.getAsArrayType(FieldType))
1055        FieldType = Array->getElementType();
1056      if (const RecordType *FieldClassType = FieldType->getAsRecordType()) {
1057        const CXXRecordDecl *FieldClassDecl
1058          = cast<CXXRecordDecl>(FieldClassType->getDecl());
1059        HasConstCopyAssignment
1060          = FieldClassDecl->hasConstCopyAssignment(Context);
1061      }
1062    }
1063
1064    //   Otherwise, the implicitly declared copy assignment operator will
1065    //   have the form
1066    //
1067    //       X& X::operator=(X&)
1068    QualType ArgType = ClassType;
1069    QualType RetType = Context.getLValueReferenceType(ArgType);
1070    if (HasConstCopyAssignment)
1071      ArgType = ArgType.withConst();
1072    ArgType = Context.getLValueReferenceType(ArgType);
1073
1074    //   An implicitly-declared copy assignment operator is an inline public
1075    //   member of its class.
1076    DeclarationName Name =
1077      Context.DeclarationNames.getCXXOperatorName(OO_Equal);
1078    CXXMethodDecl *CopyAssignment =
1079      CXXMethodDecl::Create(Context, ClassDecl, ClassDecl->getLocation(), Name,
1080                            Context.getFunctionType(RetType, &ArgType, 1,
1081                                                    false, 0),
1082                            /*isStatic=*/false, /*isInline=*/true);
1083    CopyAssignment->setAccess(AS_public);
1084    CopyAssignment->setImplicit();
1085
1086    // Add the parameter to the operator.
1087    ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment,
1088                                                 ClassDecl->getLocation(),
1089                                                 /*IdentifierInfo=*/0,
1090                                                 ArgType, VarDecl::None, 0);
1091    CopyAssignment->setParams(Context, &FromParam, 1);
1092
1093    // Don't call addedAssignmentOperator. There is no way to distinguish an
1094    // implicit from an explicit assignment operator.
1095    ClassDecl->addDecl(CopyAssignment);
1096  }
1097
1098  if (!ClassDecl->hasUserDeclaredDestructor()) {
1099    // C++ [class.dtor]p2:
1100    //   If a class has no user-declared destructor, a destructor is
1101    //   declared implicitly. An implicitly-declared destructor is an
1102    //   inline public member of its class.
1103    DeclarationName Name
1104      = Context.DeclarationNames.getCXXDestructorName(ClassType);
1105    CXXDestructorDecl *Destructor
1106      = CXXDestructorDecl::Create(Context, ClassDecl,
1107                                  ClassDecl->getLocation(), Name,
1108                                  Context.getFunctionType(Context.VoidTy,
1109                                                          0, 0, false, 0),
1110                                  /*isInline=*/true,
1111                                  /*isImplicitlyDeclared=*/true);
1112    Destructor->setAccess(AS_public);
1113    Destructor->setImplicit();
1114    ClassDecl->addDecl(Destructor);
1115  }
1116}
1117
1118/// ActOnStartDelayedCXXMethodDeclaration - We have completed
1119/// parsing a top-level (non-nested) C++ class, and we are now
1120/// parsing those parts of the given Method declaration that could
1121/// not be parsed earlier (C++ [class.mem]p2), such as default
1122/// arguments. This action should enter the scope of the given
1123/// Method declaration as if we had just parsed the qualified method
1124/// name. However, it should not bring the parameters into scope;
1125/// that will be performed by ActOnDelayedCXXMethodParameter.
1126void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, DeclTy *Method) {
1127  CXXScopeSpec SS;
1128  SS.setScopeRep(((FunctionDecl*)Method)->getDeclContext());
1129  ActOnCXXEnterDeclaratorScope(S, SS);
1130}
1131
1132/// ActOnDelayedCXXMethodParameter - We've already started a delayed
1133/// C++ method declaration. We're (re-)introducing the given
1134/// function parameter into scope for use in parsing later parts of
1135/// the method declaration. For example, we could see an
1136/// ActOnParamDefaultArgument event for this parameter.
1137void Sema::ActOnDelayedCXXMethodParameter(Scope *S, DeclTy *ParamD) {
1138  ParmVarDecl *Param = (ParmVarDecl*)ParamD;
1139
1140  // If this parameter has an unparsed default argument, clear it out
1141  // to make way for the parsed default argument.
1142  if (Param->hasUnparsedDefaultArg())
1143    Param->setDefaultArg(0);
1144
1145  S->AddDecl(Param);
1146  if (Param->getDeclName())
1147    IdResolver.AddDecl(Param);
1148}
1149
1150/// ActOnFinishDelayedCXXMethodDeclaration - We have finished
1151/// processing the delayed method declaration for Method. The method
1152/// declaration is now considered finished. There may be a separate
1153/// ActOnStartOfFunctionDef action later (not necessarily
1154/// immediately!) for this method, if it was also defined inside the
1155/// class body.
1156void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, DeclTy *MethodD) {
1157  FunctionDecl *Method = (FunctionDecl*)MethodD;
1158  CXXScopeSpec SS;
1159  SS.setScopeRep(Method->getDeclContext());
1160  ActOnCXXExitDeclaratorScope(S, SS);
1161
1162  // Now that we have our default arguments, check the constructor
1163  // again. It could produce additional diagnostics or affect whether
1164  // the class has implicitly-declared destructors, among other
1165  // things.
1166  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method)) {
1167    if (CheckConstructor(Constructor))
1168      Constructor->setInvalidDecl();
1169  }
1170
1171  // Check the default arguments, which we may have added.
1172  if (!Method->isInvalidDecl())
1173    CheckCXXDefaultArguments(Method);
1174}
1175
1176/// CheckConstructorDeclarator - Called by ActOnDeclarator to check
1177/// the well-formedness of the constructor declarator @p D with type @p
1178/// R. If there are any errors in the declarator, this routine will
1179/// emit diagnostics and return true. Otherwise, it will return
1180/// false. Either way, the type @p R will be updated to reflect a
1181/// well-formed type for the constructor.
1182bool Sema::CheckConstructorDeclarator(Declarator &D, QualType &R,
1183                                      FunctionDecl::StorageClass& SC) {
1184  bool isVirtual = D.getDeclSpec().isVirtualSpecified();
1185  bool isInvalid = false;
1186
1187  // C++ [class.ctor]p3:
1188  //   A constructor shall not be virtual (10.3) or static (9.4). A
1189  //   constructor can be invoked for a const, volatile or const
1190  //   volatile object. A constructor shall not be declared const,
1191  //   volatile, or const volatile (9.3.2).
1192  if (isVirtual) {
1193    Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
1194      << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc())
1195      << SourceRange(D.getIdentifierLoc());
1196    isInvalid = true;
1197  }
1198  if (SC == FunctionDecl::Static) {
1199    Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
1200      << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
1201      << SourceRange(D.getIdentifierLoc());
1202    isInvalid = true;
1203    SC = FunctionDecl::None;
1204  }
1205  if (D.getDeclSpec().hasTypeSpecifier()) {
1206    // Constructors don't have return types, but the parser will
1207    // happily parse something like:
1208    //
1209    //   class X {
1210    //     float X(float);
1211    //   };
1212    //
1213    // The return type will be eliminated later.
1214    Diag(D.getIdentifierLoc(), diag::err_constructor_return_type)
1215      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
1216      << SourceRange(D.getIdentifierLoc());
1217  }
1218  if (R->getAsFunctionProtoType()->getTypeQuals() != 0) {
1219    DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
1220    if (FTI.TypeQuals & QualType::Const)
1221      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
1222        << "const" << SourceRange(D.getIdentifierLoc());
1223    if (FTI.TypeQuals & QualType::Volatile)
1224      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
1225        << "volatile" << SourceRange(D.getIdentifierLoc());
1226    if (FTI.TypeQuals & QualType::Restrict)
1227      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
1228        << "restrict" << SourceRange(D.getIdentifierLoc());
1229  }
1230
1231  // Rebuild the function type "R" without any type qualifiers (in
1232  // case any of the errors above fired) and with "void" as the
1233  // return type, since constructors don't have return types. We
1234  // *always* have to do this, because GetTypeForDeclarator will
1235  // put in a result type of "int" when none was specified.
1236  const FunctionProtoType *Proto = R->getAsFunctionProtoType();
1237  R = Context.getFunctionType(Context.VoidTy, Proto->arg_type_begin(),
1238                              Proto->getNumArgs(),
1239                              Proto->isVariadic(),
1240                              0);
1241
1242  return isInvalid;
1243}
1244
1245/// CheckConstructor - Checks a fully-formed constructor for
1246/// well-formedness, issuing any diagnostics required. Returns true if
1247/// the constructor declarator is invalid.
1248bool Sema::CheckConstructor(CXXConstructorDecl *Constructor) {
1249  if (Constructor->isInvalidDecl())
1250    return true;
1251
1252  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Constructor->getDeclContext());
1253  bool Invalid = false;
1254
1255  // C++ [class.copy]p3:
1256  //   A declaration of a constructor for a class X is ill-formed if
1257  //   its first parameter is of type (optionally cv-qualified) X and
1258  //   either there are no other parameters or else all other
1259  //   parameters have default arguments.
1260  if ((Constructor->getNumParams() == 1) ||
1261      (Constructor->getNumParams() > 1 &&
1262       Constructor->getParamDecl(1)->getDefaultArg() != 0)) {
1263    QualType ParamType = Constructor->getParamDecl(0)->getType();
1264    QualType ClassTy = Context.getTagDeclType(ClassDecl);
1265    if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) {
1266      Diag(Constructor->getLocation(), diag::err_constructor_byvalue_arg)
1267        << SourceRange(Constructor->getParamDecl(0)->getLocation());
1268      Invalid = true;
1269    }
1270  }
1271
1272  // Notify the class that we've added a constructor.
1273  ClassDecl->addedConstructor(Context, Constructor);
1274
1275  return Invalid;
1276}
1277
1278/// CheckDestructorDeclarator - Called by ActOnDeclarator to check
1279/// the well-formednes of the destructor declarator @p D with type @p
1280/// R. If there are any errors in the declarator, this routine will
1281/// emit diagnostics and return true. Otherwise, it will return
1282/// false. Either way, the type @p R will be updated to reflect a
1283/// well-formed type for the destructor.
1284bool Sema::CheckDestructorDeclarator(Declarator &D, QualType &R,
1285                                     FunctionDecl::StorageClass& SC) {
1286  bool isInvalid = false;
1287
1288  // C++ [class.dtor]p1:
1289  //   [...] A typedef-name that names a class is a class-name
1290  //   (7.1.3); however, a typedef-name that names a class shall not
1291  //   be used as the identifier in the declarator for a destructor
1292  //   declaration.
1293  QualType DeclaratorType = QualType::getFromOpaquePtr(D.getDeclaratorIdType());
1294  if (DeclaratorType->getAsTypedefType()) {
1295    Diag(D.getIdentifierLoc(),  diag::err_destructor_typedef_name)
1296      << DeclaratorType;
1297    isInvalid = true;
1298  }
1299
1300  // C++ [class.dtor]p2:
1301  //   A destructor is used to destroy objects of its class type. A
1302  //   destructor takes no parameters, and no return type can be
1303  //   specified for it (not even void). The address of a destructor
1304  //   shall not be taken. A destructor shall not be static. A
1305  //   destructor can be invoked for a const, volatile or const
1306  //   volatile object. A destructor shall not be declared const,
1307  //   volatile or const volatile (9.3.2).
1308  if (SC == FunctionDecl::Static) {
1309    Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be)
1310      << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
1311      << SourceRange(D.getIdentifierLoc());
1312    isInvalid = true;
1313    SC = FunctionDecl::None;
1314  }
1315  if (D.getDeclSpec().hasTypeSpecifier()) {
1316    // Destructors don't have return types, but the parser will
1317    // happily parse something like:
1318    //
1319    //   class X {
1320    //     float ~X();
1321    //   };
1322    //
1323    // The return type will be eliminated later.
1324    Diag(D.getIdentifierLoc(), diag::err_destructor_return_type)
1325      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
1326      << SourceRange(D.getIdentifierLoc());
1327  }
1328  if (R->getAsFunctionProtoType()->getTypeQuals() != 0) {
1329    DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
1330    if (FTI.TypeQuals & QualType::Const)
1331      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
1332        << "const" << SourceRange(D.getIdentifierLoc());
1333    if (FTI.TypeQuals & QualType::Volatile)
1334      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
1335        << "volatile" << SourceRange(D.getIdentifierLoc());
1336    if (FTI.TypeQuals & QualType::Restrict)
1337      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
1338        << "restrict" << SourceRange(D.getIdentifierLoc());
1339  }
1340
1341  // Make sure we don't have any parameters.
1342  if (R->getAsFunctionProtoType()->getNumArgs() > 0) {
1343    Diag(D.getIdentifierLoc(), diag::err_destructor_with_params);
1344
1345    // Delete the parameters.
1346    D.getTypeObject(0).Fun.freeArgs();
1347  }
1348
1349  // Make sure the destructor isn't variadic.
1350  if (R->getAsFunctionProtoType()->isVariadic())
1351    Diag(D.getIdentifierLoc(), diag::err_destructor_variadic);
1352
1353  // Rebuild the function type "R" without any type qualifiers or
1354  // parameters (in case any of the errors above fired) and with
1355  // "void" as the return type, since destructors don't have return
1356  // types. We *always* have to do this, because GetTypeForDeclarator
1357  // will put in a result type of "int" when none was specified.
1358  R = Context.getFunctionType(Context.VoidTy, 0, 0, false, 0);
1359
1360  return isInvalid;
1361}
1362
1363/// CheckConversionDeclarator - Called by ActOnDeclarator to check the
1364/// well-formednes of the conversion function declarator @p D with
1365/// type @p R. If there are any errors in the declarator, this routine
1366/// will emit diagnostics and return true. Otherwise, it will return
1367/// false. Either way, the type @p R will be updated to reflect a
1368/// well-formed type for the conversion operator.
1369bool Sema::CheckConversionDeclarator(Declarator &D, QualType &R,
1370                                     FunctionDecl::StorageClass& SC) {
1371  bool isInvalid = false;
1372
1373  // C++ [class.conv.fct]p1:
1374  //   Neither parameter types nor return type can be specified. The
1375  //   type of a conversion function (8.3.5) is “function taking no
1376  //   parameter returning conversion-type-id.”
1377  if (SC == FunctionDecl::Static) {
1378    Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member)
1379      << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
1380      << SourceRange(D.getIdentifierLoc());
1381    isInvalid = true;
1382    SC = FunctionDecl::None;
1383  }
1384  if (D.getDeclSpec().hasTypeSpecifier()) {
1385    // Conversion functions don't have return types, but the parser will
1386    // happily parse something like:
1387    //
1388    //   class X {
1389    //     float operator bool();
1390    //   };
1391    //
1392    // The return type will be changed later anyway.
1393    Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type)
1394      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
1395      << SourceRange(D.getIdentifierLoc());
1396  }
1397
1398  // Make sure we don't have any parameters.
1399  if (R->getAsFunctionProtoType()->getNumArgs() > 0) {
1400    Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params);
1401
1402    // Delete the parameters.
1403    D.getTypeObject(0).Fun.freeArgs();
1404  }
1405
1406  // Make sure the conversion function isn't variadic.
1407  if (R->getAsFunctionProtoType()->isVariadic())
1408    Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic);
1409
1410  // C++ [class.conv.fct]p4:
1411  //   The conversion-type-id shall not represent a function type nor
1412  //   an array type.
1413  QualType ConvType = QualType::getFromOpaquePtr(D.getDeclaratorIdType());
1414  if (ConvType->isArrayType()) {
1415    Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array);
1416    ConvType = Context.getPointerType(ConvType);
1417  } else if (ConvType->isFunctionType()) {
1418    Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function);
1419    ConvType = Context.getPointerType(ConvType);
1420  }
1421
1422  // Rebuild the function type "R" without any parameters (in case any
1423  // of the errors above fired) and with the conversion type as the
1424  // return type.
1425  R = Context.getFunctionType(ConvType, 0, 0, false,
1426                              R->getAsFunctionProtoType()->getTypeQuals());
1427
1428  // C++0x explicit conversion operators.
1429  if (D.getDeclSpec().isExplicitSpecified() && !getLangOptions().CPlusPlus0x)
1430    Diag(D.getDeclSpec().getExplicitSpecLoc(),
1431         diag::warn_explicit_conversion_functions)
1432      << SourceRange(D.getDeclSpec().getExplicitSpecLoc());
1433
1434  return isInvalid;
1435}
1436
1437/// ActOnConversionDeclarator - Called by ActOnDeclarator to complete
1438/// the declaration of the given C++ conversion function. This routine
1439/// is responsible for recording the conversion function in the C++
1440/// class, if possible.
1441Sema::DeclTy *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) {
1442  assert(Conversion && "Expected to receive a conversion function declaration");
1443
1444  // Set the lexical context of this conversion function
1445  Conversion->setLexicalDeclContext(CurContext);
1446
1447  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext());
1448
1449  // Make sure we aren't redeclaring the conversion function.
1450  QualType ConvType = Context.getCanonicalType(Conversion->getConversionType());
1451
1452  // C++ [class.conv.fct]p1:
1453  //   [...] A conversion function is never used to convert a
1454  //   (possibly cv-qualified) object to the (possibly cv-qualified)
1455  //   same object type (or a reference to it), to a (possibly
1456  //   cv-qualified) base class of that type (or a reference to it),
1457  //   or to (possibly cv-qualified) void.
1458  // FIXME: Suppress this warning if the conversion function ends up
1459  // being a virtual function that overrides a virtual function in a
1460  // base class.
1461  QualType ClassType
1462    = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
1463  if (const ReferenceType *ConvTypeRef = ConvType->getAsReferenceType())
1464    ConvType = ConvTypeRef->getPointeeType();
1465  if (ConvType->isRecordType()) {
1466    ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType();
1467    if (ConvType == ClassType)
1468      Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used)
1469        << ClassType;
1470    else if (IsDerivedFrom(ClassType, ConvType))
1471      Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used)
1472        <<  ClassType << ConvType;
1473  } else if (ConvType->isVoidType()) {
1474    Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used)
1475      << ClassType << ConvType;
1476  }
1477
1478  if (Conversion->getPreviousDeclaration()) {
1479    OverloadedFunctionDecl *Conversions = ClassDecl->getConversionFunctions();
1480    for (OverloadedFunctionDecl::function_iterator
1481           Conv = Conversions->function_begin(),
1482           ConvEnd = Conversions->function_end();
1483         Conv != ConvEnd; ++Conv) {
1484      if (*Conv == Conversion->getPreviousDeclaration()) {
1485        *Conv = Conversion;
1486        return (DeclTy *)Conversion;
1487      }
1488    }
1489    assert(Conversion->isInvalidDecl() && "Conversion should not get here.");
1490  } else
1491    ClassDecl->addConversionFunction(Context, Conversion);
1492
1493  return (DeclTy *)Conversion;
1494}
1495
1496//===----------------------------------------------------------------------===//
1497// Namespace Handling
1498//===----------------------------------------------------------------------===//
1499
1500/// ActOnStartNamespaceDef - This is called at the start of a namespace
1501/// definition.
1502Sema::DeclTy *Sema::ActOnStartNamespaceDef(Scope *NamespcScope,
1503                                           SourceLocation IdentLoc,
1504                                           IdentifierInfo *II,
1505                                           SourceLocation LBrace) {
1506  NamespaceDecl *Namespc =
1507      NamespaceDecl::Create(Context, CurContext, IdentLoc, II);
1508  Namespc->setLBracLoc(LBrace);
1509
1510  Scope *DeclRegionScope = NamespcScope->getParent();
1511
1512  if (II) {
1513    // C++ [namespace.def]p2:
1514    // The identifier in an original-namespace-definition shall not have been
1515    // previously defined in the declarative region in which the
1516    // original-namespace-definition appears. The identifier in an
1517    // original-namespace-definition is the name of the namespace. Subsequently
1518    // in that declarative region, it is treated as an original-namespace-name.
1519
1520    NamedDecl *PrevDecl = LookupName(DeclRegionScope, II, LookupOrdinaryName,
1521                                     true);
1522
1523    if (NamespaceDecl *OrigNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl)) {
1524      // This is an extended namespace definition.
1525      // Attach this namespace decl to the chain of extended namespace
1526      // definitions.
1527      OrigNS->setNextNamespace(Namespc);
1528      Namespc->setOriginalNamespace(OrigNS->getOriginalNamespace());
1529
1530      // Remove the previous declaration from the scope.
1531      if (DeclRegionScope->isDeclScope(OrigNS)) {
1532        IdResolver.RemoveDecl(OrigNS);
1533        DeclRegionScope->RemoveDecl(OrigNS);
1534      }
1535    } else if (PrevDecl) {
1536      // This is an invalid name redefinition.
1537      Diag(Namespc->getLocation(), diag::err_redefinition_different_kind)
1538       << Namespc->getDeclName();
1539      Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1540      Namespc->setInvalidDecl();
1541      // Continue on to push Namespc as current DeclContext and return it.
1542    }
1543
1544    PushOnScopeChains(Namespc, DeclRegionScope);
1545  } else {
1546    // FIXME: Handle anonymous namespaces
1547  }
1548
1549  // Although we could have an invalid decl (i.e. the namespace name is a
1550  // redefinition), push it as current DeclContext and try to continue parsing.
1551  // FIXME: We should be able to push Namespc here, so that the
1552  // each DeclContext for the namespace has the declarations
1553  // that showed up in that particular namespace definition.
1554  PushDeclContext(NamespcScope, Namespc);
1555  return Namespc;
1556}
1557
1558/// ActOnFinishNamespaceDef - This callback is called after a namespace is
1559/// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef.
1560void Sema::ActOnFinishNamespaceDef(DeclTy *D, SourceLocation RBrace) {
1561  Decl *Dcl = static_cast<Decl *>(D);
1562  NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl);
1563  assert(Namespc && "Invalid parameter, expected NamespaceDecl");
1564  Namespc->setRBracLoc(RBrace);
1565  PopDeclContext();
1566}
1567
1568Sema::DeclTy *Sema::ActOnUsingDirective(Scope *S,
1569                                        SourceLocation UsingLoc,
1570                                        SourceLocation NamespcLoc,
1571                                        const CXXScopeSpec &SS,
1572                                        SourceLocation IdentLoc,
1573                                        IdentifierInfo *NamespcName,
1574                                        AttributeList *AttrList) {
1575  assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
1576  assert(NamespcName && "Invalid NamespcName.");
1577  assert(IdentLoc.isValid() && "Invalid NamespceName location.");
1578  assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
1579
1580  UsingDirectiveDecl *UDir = 0;
1581
1582  // Lookup namespace name.
1583  LookupResult R = LookupParsedName(S, &SS, NamespcName,
1584                                    LookupNamespaceName, false);
1585  if (R.isAmbiguous()) {
1586    DiagnoseAmbiguousLookup(R, NamespcName, IdentLoc);
1587    return 0;
1588  }
1589  if (NamedDecl *NS = R) {
1590    assert(isa<NamespaceDecl>(NS) && "expected namespace decl");
1591    // C++ [namespace.udir]p1:
1592    //   A using-directive specifies that the names in the nominated
1593    //   namespace can be used in the scope in which the
1594    //   using-directive appears after the using-directive. During
1595    //   unqualified name lookup (3.4.1), the names appear as if they
1596    //   were declared in the nearest enclosing namespace which
1597    //   contains both the using-directive and the nominated
1598    //   namespace. [Note: in this context, “contains” means “contains
1599    //   directly or indirectly”. ]
1600
1601    // Find enclosing context containing both using-directive and
1602    // nominated namespace.
1603    DeclContext *CommonAncestor = cast<DeclContext>(NS);
1604    while (CommonAncestor && !CommonAncestor->Encloses(CurContext))
1605      CommonAncestor = CommonAncestor->getParent();
1606
1607    UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc,
1608                                      NamespcLoc, IdentLoc,
1609                                      cast<NamespaceDecl>(NS),
1610                                      CommonAncestor);
1611    PushUsingDirective(S, UDir);
1612  } else {
1613    Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
1614  }
1615
1616  // FIXME: We ignore attributes for now.
1617  delete AttrList;
1618  return UDir;
1619}
1620
1621void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) {
1622  // If scope has associated entity, then using directive is at namespace
1623  // or translation unit scope. We add UsingDirectiveDecls, into
1624  // it's lookup structure.
1625  if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity()))
1626    Ctx->addDecl(UDir);
1627  else
1628    // Otherwise it is block-sope. using-directives will affect lookup
1629    // only to the end of scope.
1630    S->PushUsingDirective(UDir);
1631}
1632
1633/// AddCXXDirectInitializerToDecl - This action is called immediately after
1634/// ActOnDeclarator, when a C++ direct initializer is present.
1635/// e.g: "int x(1);"
1636void Sema::AddCXXDirectInitializerToDecl(DeclTy *Dcl, SourceLocation LParenLoc,
1637                                         MultiExprArg Exprs,
1638                                         SourceLocation *CommaLocs,
1639                                         SourceLocation RParenLoc) {
1640  unsigned NumExprs = Exprs.size();
1641  assert(NumExprs != 0 && Exprs.get() && "missing expressions");
1642  Decl *RealDecl = static_cast<Decl *>(Dcl);
1643
1644  // If there is no declaration, there was an error parsing it.  Just ignore
1645  // the initializer.
1646  if (RealDecl == 0) {
1647    return;
1648  }
1649
1650  VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl);
1651  if (!VDecl) {
1652    Diag(RealDecl->getLocation(), diag::err_illegal_initializer);
1653    RealDecl->setInvalidDecl();
1654    return;
1655  }
1656
1657  // We will treat direct-initialization as a copy-initialization:
1658  //    int x(1);  -as-> int x = 1;
1659  //    ClassType x(a,b,c); -as-> ClassType x = ClassType(a,b,c);
1660  //
1661  // Clients that want to distinguish between the two forms, can check for
1662  // direct initializer using VarDecl::hasCXXDirectInitializer().
1663  // A major benefit is that clients that don't particularly care about which
1664  // exactly form was it (like the CodeGen) can handle both cases without
1665  // special case code.
1666
1667  // C++ 8.5p11:
1668  // The form of initialization (using parentheses or '=') is generally
1669  // insignificant, but does matter when the entity being initialized has a
1670  // class type.
1671  QualType DeclInitType = VDecl->getType();
1672  if (const ArrayType *Array = Context.getAsArrayType(DeclInitType))
1673    DeclInitType = Array->getElementType();
1674
1675  if (VDecl->getType()->isRecordType()) {
1676    CXXConstructorDecl *Constructor
1677      = PerformInitializationByConstructor(DeclInitType,
1678                                           (Expr **)Exprs.get(), NumExprs,
1679                                           VDecl->getLocation(),
1680                                           SourceRange(VDecl->getLocation(),
1681                                                       RParenLoc),
1682                                           VDecl->getDeclName(),
1683                                           IK_Direct);
1684    if (!Constructor)
1685      RealDecl->setInvalidDecl();
1686    else
1687      Exprs.release();
1688
1689    // Let clients know that initialization was done with a direct
1690    // initializer.
1691    VDecl->setCXXDirectInitializer(true);
1692
1693    // FIXME: Add ExprTys and Constructor to the RealDecl as part of
1694    // the initializer.
1695    return;
1696  }
1697
1698  if (NumExprs > 1) {
1699    Diag(CommaLocs[0], diag::err_builtin_direct_init_more_than_one_arg)
1700      << SourceRange(VDecl->getLocation(), RParenLoc);
1701    RealDecl->setInvalidDecl();
1702    return;
1703  }
1704
1705  // Let clients know that initialization was done with a direct initializer.
1706  VDecl->setCXXDirectInitializer(true);
1707
1708  assert(NumExprs == 1 && "Expected 1 expression");
1709  // Set the init expression, handles conversions.
1710  AddInitializerToDecl(Dcl, ExprArg(*this, Exprs.release()[0]),
1711                       /*DirectInit=*/true);
1712}
1713
1714/// PerformInitializationByConstructor - Perform initialization by
1715/// constructor (C++ [dcl.init]p14), which may occur as part of
1716/// direct-initialization or copy-initialization. We are initializing
1717/// an object of type @p ClassType with the given arguments @p
1718/// Args. @p Loc is the location in the source code where the
1719/// initializer occurs (e.g., a declaration, member initializer,
1720/// functional cast, etc.) while @p Range covers the whole
1721/// initialization. @p InitEntity is the entity being initialized,
1722/// which may by the name of a declaration or a type. @p Kind is the
1723/// kind of initialization we're performing, which affects whether
1724/// explicit constructors will be considered. When successful, returns
1725/// the constructor that will be used to perform the initialization;
1726/// when the initialization fails, emits a diagnostic and returns
1727/// null.
1728CXXConstructorDecl *
1729Sema::PerformInitializationByConstructor(QualType ClassType,
1730                                         Expr **Args, unsigned NumArgs,
1731                                         SourceLocation Loc, SourceRange Range,
1732                                         DeclarationName InitEntity,
1733                                         InitializationKind Kind) {
1734  const RecordType *ClassRec = ClassType->getAsRecordType();
1735  assert(ClassRec && "Can only initialize a class type here");
1736
1737  // C++ [dcl.init]p14:
1738  //
1739  //   If the initialization is direct-initialization, or if it is
1740  //   copy-initialization where the cv-unqualified version of the
1741  //   source type is the same class as, or a derived class of, the
1742  //   class of the destination, constructors are considered. The
1743  //   applicable constructors are enumerated (13.3.1.3), and the
1744  //   best one is chosen through overload resolution (13.3). The
1745  //   constructor so selected is called to initialize the object,
1746  //   with the initializer expression(s) as its argument(s). If no
1747  //   constructor applies, or the overload resolution is ambiguous,
1748  //   the initialization is ill-formed.
1749  const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl());
1750  OverloadCandidateSet CandidateSet;
1751
1752  // Add constructors to the overload set.
1753  DeclarationName ConstructorName
1754    = Context.DeclarationNames.getCXXConstructorName(
1755                       Context.getCanonicalType(ClassType.getUnqualifiedType()));
1756  DeclContext::lookup_const_iterator Con, ConEnd;
1757  for (llvm::tie(Con, ConEnd) = ClassDecl->lookup(ConstructorName);
1758       Con != ConEnd; ++Con) {
1759    CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con);
1760    if ((Kind == IK_Direct) ||
1761        (Kind == IK_Copy && Constructor->isConvertingConstructor()) ||
1762        (Kind == IK_Default && Constructor->isDefaultConstructor()))
1763      AddOverloadCandidate(Constructor, Args, NumArgs, CandidateSet);
1764  }
1765
1766  // FIXME: When we decide not to synthesize the implicitly-declared
1767  // constructors, we'll need to make them appear here.
1768
1769  OverloadCandidateSet::iterator Best;
1770  switch (BestViableFunction(CandidateSet, Best)) {
1771  case OR_Success:
1772    // We found a constructor. Return it.
1773    return cast<CXXConstructorDecl>(Best->Function);
1774
1775  case OR_No_Viable_Function:
1776    if (InitEntity)
1777      Diag(Loc, diag::err_ovl_no_viable_function_in_init)
1778        << InitEntity << Range;
1779    else
1780      Diag(Loc, diag::err_ovl_no_viable_function_in_init)
1781        << ClassType << Range;
1782    PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false);
1783    return 0;
1784
1785  case OR_Ambiguous:
1786    if (InitEntity)
1787      Diag(Loc, diag::err_ovl_ambiguous_init) << InitEntity << Range;
1788    else
1789      Diag(Loc, diag::err_ovl_ambiguous_init) << ClassType << Range;
1790    PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true);
1791    return 0;
1792
1793  case OR_Deleted:
1794    if (InitEntity)
1795      Diag(Loc, diag::err_ovl_deleted_init)
1796        << Best->Function->isDeleted()
1797        << InitEntity << Range;
1798    else
1799      Diag(Loc, diag::err_ovl_deleted_init)
1800        << Best->Function->isDeleted()
1801        << InitEntity << Range;
1802    PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true);
1803    return 0;
1804  }
1805
1806  return 0;
1807}
1808
1809/// CompareReferenceRelationship - Compare the two types T1 and T2 to
1810/// determine whether they are reference-related,
1811/// reference-compatible, reference-compatible with added
1812/// qualification, or incompatible, for use in C++ initialization by
1813/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
1814/// type, and the first type (T1) is the pointee type of the reference
1815/// type being initialized.
1816Sema::ReferenceCompareResult
1817Sema::CompareReferenceRelationship(QualType T1, QualType T2,
1818                                   bool& DerivedToBase) {
1819  assert(!T1->isReferenceType() &&
1820    "T1 must be the pointee type of the reference type");
1821  assert(!T2->isReferenceType() && "T2 cannot be a reference type");
1822
1823  T1 = Context.getCanonicalType(T1);
1824  T2 = Context.getCanonicalType(T2);
1825  QualType UnqualT1 = T1.getUnqualifiedType();
1826  QualType UnqualT2 = T2.getUnqualifiedType();
1827
1828  // C++ [dcl.init.ref]p4:
1829  //   Given types “cv1 T1” and “cv2 T2,” “cv1 T1” is
1830  //   reference-related to “cv2 T2” if T1 is the same type as T2, or
1831  //   T1 is a base class of T2.
1832  if (UnqualT1 == UnqualT2)
1833    DerivedToBase = false;
1834  else if (IsDerivedFrom(UnqualT2, UnqualT1))
1835    DerivedToBase = true;
1836  else
1837    return Ref_Incompatible;
1838
1839  // At this point, we know that T1 and T2 are reference-related (at
1840  // least).
1841
1842  // C++ [dcl.init.ref]p4:
1843  //   "cv1 T1” is reference-compatible with “cv2 T2” if T1 is
1844  //   reference-related to T2 and cv1 is the same cv-qualification
1845  //   as, or greater cv-qualification than, cv2. For purposes of
1846  //   overload resolution, cases for which cv1 is greater
1847  //   cv-qualification than cv2 are identified as
1848  //   reference-compatible with added qualification (see 13.3.3.2).
1849  if (T1.getCVRQualifiers() == T2.getCVRQualifiers())
1850    return Ref_Compatible;
1851  else if (T1.isMoreQualifiedThan(T2))
1852    return Ref_Compatible_With_Added_Qualification;
1853  else
1854    return Ref_Related;
1855}
1856
1857/// CheckReferenceInit - Check the initialization of a reference
1858/// variable with the given initializer (C++ [dcl.init.ref]). Init is
1859/// the initializer (either a simple initializer or an initializer
1860/// list), and DeclType is the type of the declaration. When ICS is
1861/// non-null, this routine will compute the implicit conversion
1862/// sequence according to C++ [over.ics.ref] and will not produce any
1863/// diagnostics; when ICS is null, it will emit diagnostics when any
1864/// errors are found. Either way, a return value of true indicates
1865/// that there was a failure, a return value of false indicates that
1866/// the reference initialization succeeded.
1867///
1868/// When @p SuppressUserConversions, user-defined conversions are
1869/// suppressed.
1870/// When @p AllowExplicit, we also permit explicit user-defined
1871/// conversion functions.
1872bool
1873Sema::CheckReferenceInit(Expr *&Init, QualType &DeclType,
1874                         ImplicitConversionSequence *ICS,
1875                         bool SuppressUserConversions,
1876                         bool AllowExplicit) {
1877  assert(DeclType->isReferenceType() && "Reference init needs a reference");
1878
1879  QualType T1 = DeclType->getAsReferenceType()->getPointeeType();
1880  QualType T2 = Init->getType();
1881
1882  // If the initializer is the address of an overloaded function, try
1883  // to resolve the overloaded function. If all goes well, T2 is the
1884  // type of the resulting function.
1885  if (Context.getCanonicalType(T2) == Context.OverloadTy) {
1886    FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Init, DeclType,
1887                                                          ICS != 0);
1888    if (Fn) {
1889      // Since we're performing this reference-initialization for
1890      // real, update the initializer with the resulting function.
1891      if (!ICS) {
1892        if (DiagnoseUseOfDecl(Fn, Init->getSourceRange().getBegin()))
1893          return true;
1894
1895        FixOverloadedFunctionReference(Init, Fn);
1896      }
1897
1898      T2 = Fn->getType();
1899    }
1900  }
1901
1902  // Compute some basic properties of the types and the initializer.
1903  bool isRValRef = DeclType->isRValueReferenceType();
1904  bool DerivedToBase = false;
1905  Expr::isLvalueResult InitLvalue = Init->isLvalue(Context);
1906  ReferenceCompareResult RefRelationship
1907    = CompareReferenceRelationship(T1, T2, DerivedToBase);
1908
1909  // Most paths end in a failed conversion.
1910  if (ICS)
1911    ICS->ConversionKind = ImplicitConversionSequence::BadConversion;
1912
1913  // C++ [dcl.init.ref]p5:
1914  //   A reference to type “cv1 T1” is initialized by an expression
1915  //   of type “cv2 T2” as follows:
1916
1917  //     -- If the initializer expression
1918
1919  bool BindsDirectly = false;
1920  //       -- is an lvalue (but is not a bit-field), and “cv1 T1” is
1921  //          reference-compatible with “cv2 T2,” or
1922  //
1923  // Note that the bit-field check is skipped if we are just computing
1924  // the implicit conversion sequence (C++ [over.best.ics]p2).
1925  if (InitLvalue == Expr::LV_Valid && (ICS || !Init->isBitField()) &&
1926      RefRelationship >= Ref_Compatible_With_Added_Qualification) {
1927    BindsDirectly = true;
1928
1929    // Rvalue references cannot bind to lvalues (N2812).
1930    if (isRValRef) {
1931      if (!ICS)
1932        Diag(Init->getSourceRange().getBegin(), diag::err_lvalue_to_rvalue_ref)
1933          << Init->getSourceRange();
1934      return true;
1935    }
1936
1937    if (ICS) {
1938      // C++ [over.ics.ref]p1:
1939      //   When a parameter of reference type binds directly (8.5.3)
1940      //   to an argument expression, the implicit conversion sequence
1941      //   is the identity conversion, unless the argument expression
1942      //   has a type that is a derived class of the parameter type,
1943      //   in which case the implicit conversion sequence is a
1944      //   derived-to-base Conversion (13.3.3.1).
1945      ICS->ConversionKind = ImplicitConversionSequence::StandardConversion;
1946      ICS->Standard.First = ICK_Identity;
1947      ICS->Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity;
1948      ICS->Standard.Third = ICK_Identity;
1949      ICS->Standard.FromTypePtr = T2.getAsOpaquePtr();
1950      ICS->Standard.ToTypePtr = T1.getAsOpaquePtr();
1951      ICS->Standard.ReferenceBinding = true;
1952      ICS->Standard.DirectBinding = true;
1953
1954      // Nothing more to do: the inaccessibility/ambiguity check for
1955      // derived-to-base conversions is suppressed when we're
1956      // computing the implicit conversion sequence (C++
1957      // [over.best.ics]p2).
1958      return false;
1959    } else {
1960      // Perform the conversion.
1961      // FIXME: Binding to a subobject of the lvalue is going to require
1962      // more AST annotation than this.
1963      ImpCastExprToType(Init, T1, /*isLvalue=*/true);
1964    }
1965  }
1966
1967  //       -- has a class type (i.e., T2 is a class type) and can be
1968  //          implicitly converted to an lvalue of type “cv3 T3,”
1969  //          where “cv1 T1” is reference-compatible with “cv3 T3”
1970  //          92) (this conversion is selected by enumerating the
1971  //          applicable conversion functions (13.3.1.6) and choosing
1972  //          the best one through overload resolution (13.3)),
1973  if (!isRValRef && !SuppressUserConversions && T2->isRecordType()) {
1974    // FIXME: Look for conversions in base classes!
1975    CXXRecordDecl *T2RecordDecl
1976      = dyn_cast<CXXRecordDecl>(T2->getAsRecordType()->getDecl());
1977
1978    OverloadCandidateSet CandidateSet;
1979    OverloadedFunctionDecl *Conversions
1980      = T2RecordDecl->getConversionFunctions();
1981    for (OverloadedFunctionDecl::function_iterator Func
1982           = Conversions->function_begin();
1983         Func != Conversions->function_end(); ++Func) {
1984      CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func);
1985
1986      // If the conversion function doesn't return a reference type,
1987      // it can't be considered for this conversion.
1988      if (Conv->getConversionType()->isLValueReferenceType() &&
1989          (AllowExplicit || !Conv->isExplicit()))
1990        AddConversionCandidate(Conv, Init, DeclType, CandidateSet);
1991    }
1992
1993    OverloadCandidateSet::iterator Best;
1994    switch (BestViableFunction(CandidateSet, Best)) {
1995    case OR_Success:
1996      // This is a direct binding.
1997      BindsDirectly = true;
1998
1999      if (ICS) {
2000        // C++ [over.ics.ref]p1:
2001        //
2002        //   [...] If the parameter binds directly to the result of
2003        //   applying a conversion function to the argument
2004        //   expression, the implicit conversion sequence is a
2005        //   user-defined conversion sequence (13.3.3.1.2), with the
2006        //   second standard conversion sequence either an identity
2007        //   conversion or, if the conversion function returns an
2008        //   entity of a type that is a derived class of the parameter
2009        //   type, a derived-to-base Conversion.
2010        ICS->ConversionKind = ImplicitConversionSequence::UserDefinedConversion;
2011        ICS->UserDefined.Before = Best->Conversions[0].Standard;
2012        ICS->UserDefined.After = Best->FinalConversion;
2013        ICS->UserDefined.ConversionFunction = Best->Function;
2014        assert(ICS->UserDefined.After.ReferenceBinding &&
2015               ICS->UserDefined.After.DirectBinding &&
2016               "Expected a direct reference binding!");
2017        return false;
2018      } else {
2019        // Perform the conversion.
2020        // FIXME: Binding to a subobject of the lvalue is going to require
2021        // more AST annotation than this.
2022        ImpCastExprToType(Init, T1, /*isLvalue=*/true);
2023      }
2024      break;
2025
2026    case OR_Ambiguous:
2027      assert(false && "Ambiguous reference binding conversions not implemented.");
2028      return true;
2029
2030    case OR_No_Viable_Function:
2031    case OR_Deleted:
2032      // There was no suitable conversion, or we found a deleted
2033      // conversion; continue with other checks.
2034      break;
2035    }
2036  }
2037
2038  if (BindsDirectly) {
2039    // C++ [dcl.init.ref]p4:
2040    //   [...] In all cases where the reference-related or
2041    //   reference-compatible relationship of two types is used to
2042    //   establish the validity of a reference binding, and T1 is a
2043    //   base class of T2, a program that necessitates such a binding
2044    //   is ill-formed if T1 is an inaccessible (clause 11) or
2045    //   ambiguous (10.2) base class of T2.
2046    //
2047    // Note that we only check this condition when we're allowed to
2048    // complain about errors, because we should not be checking for
2049    // ambiguity (or inaccessibility) unless the reference binding
2050    // actually happens.
2051    if (DerivedToBase)
2052      return CheckDerivedToBaseConversion(T2, T1,
2053                                          Init->getSourceRange().getBegin(),
2054                                          Init->getSourceRange());
2055    else
2056      return false;
2057  }
2058
2059  //     -- Otherwise, the reference shall be to a non-volatile const
2060  //        type (i.e., cv1 shall be const), or shall be an rvalue reference.
2061  if (!isRValRef && T1.getCVRQualifiers() != QualType::Const) {
2062    if (!ICS)
2063      Diag(Init->getSourceRange().getBegin(),
2064           diag::err_not_reference_to_const_init)
2065        << T1 << (InitLvalue != Expr::LV_Valid? "temporary" : "value")
2066        << T2 << Init->getSourceRange();
2067    return true;
2068  }
2069
2070  //       -- If the initializer expression is an rvalue, with T2 a
2071  //          class type, and “cv1 T1” is reference-compatible with
2072  //          “cv2 T2,” the reference is bound in one of the
2073  //          following ways (the choice is implementation-defined):
2074  //
2075  //          -- The reference is bound to the object represented by
2076  //             the rvalue (see 3.10) or to a sub-object within that
2077  //             object.
2078  //
2079  //          -- A temporary of type “cv1 T2” [sic] is created, and
2080  //             a constructor is called to copy the entire rvalue
2081  //             object into the temporary. The reference is bound to
2082  //             the temporary or to a sub-object within the
2083  //             temporary.
2084  //
2085  //          The constructor that would be used to make the copy
2086  //          shall be callable whether or not the copy is actually
2087  //          done.
2088  //
2089  // Note that C++0x [dcl.ref.init]p5 takes away this implementation
2090  // freedom, so we will always take the first option and never build
2091  // a temporary in this case. FIXME: We will, however, have to check
2092  // for the presence of a copy constructor in C++98/03 mode.
2093  if (InitLvalue != Expr::LV_Valid && T2->isRecordType() &&
2094      RefRelationship >= Ref_Compatible_With_Added_Qualification) {
2095    if (ICS) {
2096      ICS->ConversionKind = ImplicitConversionSequence::StandardConversion;
2097      ICS->Standard.First = ICK_Identity;
2098      ICS->Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity;
2099      ICS->Standard.Third = ICK_Identity;
2100      ICS->Standard.FromTypePtr = T2.getAsOpaquePtr();
2101      ICS->Standard.ToTypePtr = T1.getAsOpaquePtr();
2102      ICS->Standard.ReferenceBinding = true;
2103      ICS->Standard.DirectBinding = false;
2104    } else {
2105      // FIXME: Binding to a subobject of the rvalue is going to require
2106      // more AST annotation than this.
2107      ImpCastExprToType(Init, T1, /*isLvalue=*/true);
2108    }
2109    return false;
2110  }
2111
2112  //       -- Otherwise, a temporary of type “cv1 T1” is created and
2113  //          initialized from the initializer expression using the
2114  //          rules for a non-reference copy initialization (8.5). The
2115  //          reference is then bound to the temporary. If T1 is
2116  //          reference-related to T2, cv1 must be the same
2117  //          cv-qualification as, or greater cv-qualification than,
2118  //          cv2; otherwise, the program is ill-formed.
2119  if (RefRelationship == Ref_Related) {
2120    // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
2121    // we would be reference-compatible or reference-compatible with
2122    // added qualification. But that wasn't the case, so the reference
2123    // initialization fails.
2124    if (!ICS)
2125      Diag(Init->getSourceRange().getBegin(),
2126           diag::err_reference_init_drops_quals)
2127        << T1 << (InitLvalue != Expr::LV_Valid? "temporary" : "value")
2128        << T2 << Init->getSourceRange();
2129    return true;
2130  }
2131
2132  // If at least one of the types is a class type, the types are not
2133  // related, and we aren't allowed any user conversions, the
2134  // reference binding fails. This case is important for breaking
2135  // recursion, since TryImplicitConversion below will attempt to
2136  // create a temporary through the use of a copy constructor.
2137  if (SuppressUserConversions && RefRelationship == Ref_Incompatible &&
2138      (T1->isRecordType() || T2->isRecordType())) {
2139    if (!ICS)
2140      Diag(Init->getSourceRange().getBegin(),
2141           diag::err_typecheck_convert_incompatible)
2142        << DeclType << Init->getType() << "initializing" << Init->getSourceRange();
2143    return true;
2144  }
2145
2146  // Actually try to convert the initializer to T1.
2147  if (ICS) {
2148    /// C++ [over.ics.ref]p2:
2149    ///
2150    ///   When a parameter of reference type is not bound directly to
2151    ///   an argument expression, the conversion sequence is the one
2152    ///   required to convert the argument expression to the
2153    ///   underlying type of the reference according to
2154    ///   13.3.3.1. Conceptually, this conversion sequence corresponds
2155    ///   to copy-initializing a temporary of the underlying type with
2156    ///   the argument expression. Any difference in top-level
2157    ///   cv-qualification is subsumed by the initialization itself
2158    ///   and does not constitute a conversion.
2159    *ICS = TryImplicitConversion(Init, T1, SuppressUserConversions);
2160    return ICS->ConversionKind == ImplicitConversionSequence::BadConversion;
2161  } else {
2162    return PerformImplicitConversion(Init, T1, "initializing");
2163  }
2164}
2165
2166/// CheckOverloadedOperatorDeclaration - Check whether the declaration
2167/// of this overloaded operator is well-formed. If so, returns false;
2168/// otherwise, emits appropriate diagnostics and returns true.
2169bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) {
2170  assert(FnDecl && FnDecl->isOverloadedOperator() &&
2171         "Expected an overloaded operator declaration");
2172
2173  OverloadedOperatorKind Op = FnDecl->getOverloadedOperator();
2174
2175  // C++ [over.oper]p5:
2176  //   The allocation and deallocation functions, operator new,
2177  //   operator new[], operator delete and operator delete[], are
2178  //   described completely in 3.7.3. The attributes and restrictions
2179  //   found in the rest of this subclause do not apply to them unless
2180  //   explicitly stated in 3.7.3.
2181  // FIXME: Write a separate routine for checking this. For now, just
2182  // allow it.
2183  if (Op == OO_New || Op == OO_Array_New ||
2184      Op == OO_Delete || Op == OO_Array_Delete)
2185    return false;
2186
2187  // C++ [over.oper]p6:
2188  //   An operator function shall either be a non-static member
2189  //   function or be a non-member function and have at least one
2190  //   parameter whose type is a class, a reference to a class, an
2191  //   enumeration, or a reference to an enumeration.
2192  if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) {
2193    if (MethodDecl->isStatic())
2194      return Diag(FnDecl->getLocation(),
2195                  diag::err_operator_overload_static) << FnDecl->getDeclName();
2196  } else {
2197    bool ClassOrEnumParam = false;
2198    for (FunctionDecl::param_iterator Param = FnDecl->param_begin(),
2199                                   ParamEnd = FnDecl->param_end();
2200         Param != ParamEnd; ++Param) {
2201      QualType ParamType = (*Param)->getType().getNonReferenceType();
2202      if (ParamType->isRecordType() || ParamType->isEnumeralType()) {
2203        ClassOrEnumParam = true;
2204        break;
2205      }
2206    }
2207
2208    if (!ClassOrEnumParam)
2209      return Diag(FnDecl->getLocation(),
2210                  diag::err_operator_overload_needs_class_or_enum)
2211        << FnDecl->getDeclName();
2212  }
2213
2214  // C++ [over.oper]p8:
2215  //   An operator function cannot have default arguments (8.3.6),
2216  //   except where explicitly stated below.
2217  //
2218  // Only the function-call operator allows default arguments
2219  // (C++ [over.call]p1).
2220  if (Op != OO_Call) {
2221    for (FunctionDecl::param_iterator Param = FnDecl->param_begin();
2222         Param != FnDecl->param_end(); ++Param) {
2223      if ((*Param)->hasUnparsedDefaultArg())
2224        return Diag((*Param)->getLocation(),
2225                    diag::err_operator_overload_default_arg)
2226          << FnDecl->getDeclName();
2227      else if (Expr *DefArg = (*Param)->getDefaultArg())
2228        return Diag((*Param)->getLocation(),
2229                    diag::err_operator_overload_default_arg)
2230          << FnDecl->getDeclName() << DefArg->getSourceRange();
2231    }
2232  }
2233
2234  static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = {
2235    { false, false, false }
2236#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
2237    , { Unary, Binary, MemberOnly }
2238#include "clang/Basic/OperatorKinds.def"
2239  };
2240
2241  bool CanBeUnaryOperator = OperatorUses[Op][0];
2242  bool CanBeBinaryOperator = OperatorUses[Op][1];
2243  bool MustBeMemberOperator = OperatorUses[Op][2];
2244
2245  // C++ [over.oper]p8:
2246  //   [...] Operator functions cannot have more or fewer parameters
2247  //   than the number required for the corresponding operator, as
2248  //   described in the rest of this subclause.
2249  unsigned NumParams = FnDecl->getNumParams()
2250                     + (isa<CXXMethodDecl>(FnDecl)? 1 : 0);
2251  if (Op != OO_Call &&
2252      ((NumParams == 1 && !CanBeUnaryOperator) ||
2253       (NumParams == 2 && !CanBeBinaryOperator) ||
2254       (NumParams < 1) || (NumParams > 2))) {
2255    // We have the wrong number of parameters.
2256    unsigned ErrorKind;
2257    if (CanBeUnaryOperator && CanBeBinaryOperator) {
2258      ErrorKind = 2;  // 2 -> unary or binary.
2259    } else if (CanBeUnaryOperator) {
2260      ErrorKind = 0;  // 0 -> unary
2261    } else {
2262      assert(CanBeBinaryOperator &&
2263             "All non-call overloaded operators are unary or binary!");
2264      ErrorKind = 1;  // 1 -> binary
2265    }
2266
2267    return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be)
2268      << FnDecl->getDeclName() << NumParams << ErrorKind;
2269  }
2270
2271  // Overloaded operators other than operator() cannot be variadic.
2272  if (Op != OO_Call &&
2273      FnDecl->getType()->getAsFunctionProtoType()->isVariadic()) {
2274    return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic)
2275      << FnDecl->getDeclName();
2276  }
2277
2278  // Some operators must be non-static member functions.
2279  if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) {
2280    return Diag(FnDecl->getLocation(),
2281                diag::err_operator_overload_must_be_member)
2282      << FnDecl->getDeclName();
2283  }
2284
2285  // C++ [over.inc]p1:
2286  //   The user-defined function called operator++ implements the
2287  //   prefix and postfix ++ operator. If this function is a member
2288  //   function with no parameters, or a non-member function with one
2289  //   parameter of class or enumeration type, it defines the prefix
2290  //   increment operator ++ for objects of that type. If the function
2291  //   is a member function with one parameter (which shall be of type
2292  //   int) or a non-member function with two parameters (the second
2293  //   of which shall be of type int), it defines the postfix
2294  //   increment operator ++ for objects of that type.
2295  if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) {
2296    ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1);
2297    bool ParamIsInt = false;
2298    if (const BuiltinType *BT = LastParam->getType()->getAsBuiltinType())
2299      ParamIsInt = BT->getKind() == BuiltinType::Int;
2300
2301    if (!ParamIsInt)
2302      return Diag(LastParam->getLocation(),
2303                  diag::err_operator_overload_post_incdec_must_be_int)
2304        << LastParam->getType() << (Op == OO_MinusMinus);
2305  }
2306
2307  // Notify the class if it got an assignment operator.
2308  if (Op == OO_Equal) {
2309    // Would have returned earlier otherwise.
2310    assert(isa<CXXMethodDecl>(FnDecl) &&
2311      "Overloaded = not member, but not filtered.");
2312    CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
2313    Method->getParent()->addedAssignmentOperator(Context, Method);
2314  }
2315
2316  return false;
2317}
2318
2319/// ActOnStartLinkageSpecification - Parsed the beginning of a C++
2320/// linkage specification, including the language and (if present)
2321/// the '{'. ExternLoc is the location of the 'extern', LangLoc is
2322/// the location of the language string literal, which is provided
2323/// by Lang/StrSize. LBraceLoc, if valid, provides the location of
2324/// the '{' brace. Otherwise, this linkage specification does not
2325/// have any braces.
2326Sema::DeclTy *Sema::ActOnStartLinkageSpecification(Scope *S,
2327                                                   SourceLocation ExternLoc,
2328                                                   SourceLocation LangLoc,
2329                                                   const char *Lang,
2330                                                   unsigned StrSize,
2331                                                   SourceLocation LBraceLoc) {
2332  LinkageSpecDecl::LanguageIDs Language;
2333  if (strncmp(Lang, "\"C\"", StrSize) == 0)
2334    Language = LinkageSpecDecl::lang_c;
2335  else if (strncmp(Lang, "\"C++\"", StrSize) == 0)
2336    Language = LinkageSpecDecl::lang_cxx;
2337  else {
2338    Diag(LangLoc, diag::err_bad_language);
2339    return 0;
2340  }
2341
2342  // FIXME: Add all the various semantics of linkage specifications
2343
2344  LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext,
2345                                               LangLoc, Language,
2346                                               LBraceLoc.isValid());
2347  CurContext->addDecl(D);
2348  PushDeclContext(S, D);
2349  return D;
2350}
2351
2352/// ActOnFinishLinkageSpecification - Completely the definition of
2353/// the C++ linkage specification LinkageSpec. If RBraceLoc is
2354/// valid, it's the position of the closing '}' brace in a linkage
2355/// specification that uses braces.
2356Sema::DeclTy *Sema::ActOnFinishLinkageSpecification(Scope *S,
2357                                                    DeclTy *LinkageSpec,
2358                                                    SourceLocation RBraceLoc) {
2359  if (LinkageSpec)
2360    PopDeclContext();
2361  return LinkageSpec;
2362}
2363
2364/// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch
2365/// handler.
2366Sema::DeclTy *Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D)
2367{
2368  QualType ExDeclType = GetTypeForDeclarator(D, S);
2369  SourceLocation Begin = D.getDeclSpec().getSourceRange().getBegin();
2370
2371  bool Invalid = false;
2372
2373  // Arrays and functions decay.
2374  if (ExDeclType->isArrayType())
2375    ExDeclType = Context.getArrayDecayedType(ExDeclType);
2376  else if (ExDeclType->isFunctionType())
2377    ExDeclType = Context.getPointerType(ExDeclType);
2378
2379  // C++ 15.3p1: The exception-declaration shall not denote an incomplete type.
2380  // The exception-declaration shall not denote a pointer or reference to an
2381  // incomplete type, other than [cv] void*.
2382  // N2844 forbids rvalue references.
2383  if(ExDeclType->isRValueReferenceType()) {
2384    Diag(Begin, diag::err_catch_rvalue_ref) << D.getSourceRange();
2385    Invalid = true;
2386  }
2387  QualType BaseType = ExDeclType;
2388  int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference
2389  unsigned DK = diag::err_catch_incomplete;
2390  if (const PointerType *Ptr = BaseType->getAsPointerType()) {
2391    BaseType = Ptr->getPointeeType();
2392    Mode = 1;
2393    DK = diag::err_catch_incomplete_ptr;
2394  } else if(const ReferenceType *Ref = BaseType->getAsReferenceType()) {
2395    // For the purpose of error recovery, we treat rvalue refs like lvalue refs.
2396    BaseType = Ref->getPointeeType();
2397    Mode = 2;
2398    DK = diag::err_catch_incomplete_ref;
2399  }
2400  if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) &&
2401      RequireCompleteType(Begin, BaseType, DK))
2402    Invalid = true;
2403
2404  // FIXME: Need to test for ability to copy-construct and destroy the
2405  // exception variable.
2406  // FIXME: Need to check for abstract classes.
2407
2408  IdentifierInfo *II = D.getIdentifier();
2409  if (NamedDecl *PrevDecl = LookupName(S, II, LookupOrdinaryName)) {
2410    // The scope should be freshly made just for us. There is just no way
2411    // it contains any previous declaration.
2412    assert(!S->isDeclScope(PrevDecl));
2413    if (PrevDecl->isTemplateParameter()) {
2414      // Maybe we will complain about the shadowed template parameter.
2415      DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
2416
2417    }
2418  }
2419
2420  VarDecl *ExDecl = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(),
2421                                    II, ExDeclType, VarDecl::None, Begin);
2422  if (D.getInvalidType() || Invalid)
2423    ExDecl->setInvalidDecl();
2424
2425  if (D.getCXXScopeSpec().isSet()) {
2426    Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator)
2427      << D.getCXXScopeSpec().getRange();
2428    ExDecl->setInvalidDecl();
2429  }
2430
2431  // Add the exception declaration into this scope.
2432  S->AddDecl(ExDecl);
2433  if (II)
2434    IdResolver.AddDecl(ExDecl);
2435
2436  ProcessDeclAttributes(ExDecl, D);
2437  return ExDecl;
2438}
2439
2440Sema::DeclTy *Sema::ActOnStaticAssertDeclaration(SourceLocation AssertLoc,
2441                                                 ExprArg assertexpr,
2442                                                 ExprArg assertmessageexpr) {
2443  Expr *AssertExpr = (Expr *)assertexpr.get();
2444  StringLiteral *AssertMessage =
2445    cast<StringLiteral>((Expr *)assertmessageexpr.get());
2446
2447  if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent()) {
2448    llvm::APSInt Value(32);
2449    if (!AssertExpr->isIntegerConstantExpr(Value, Context)) {
2450      Diag(AssertLoc, diag::err_static_assert_expression_is_not_constant) <<
2451        AssertExpr->getSourceRange();
2452      return 0;
2453    }
2454
2455    if (Value == 0) {
2456      std::string str(AssertMessage->getStrData(),
2457                      AssertMessage->getByteLength());
2458      Diag(AssertLoc, diag::err_static_assert_failed)
2459        << str << AssertExpr->getSourceRange();
2460    }
2461  }
2462
2463  assertexpr.release();
2464  assertmessageexpr.release();
2465  Decl *Decl = StaticAssertDecl::Create(Context, CurContext, AssertLoc,
2466                                        AssertExpr, AssertMessage);
2467
2468  CurContext->addDecl(Decl);
2469  return Decl;
2470}
2471