SemaDeclCXX.cpp revision c75bc2d1f6f637098abc5db4caf0551f9437471e
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(DeclPtrTy param, SourceLocation EqualLoc,
109                                ExprArg defarg) {
110  if (!param || !defarg.get())
111    return;
112
113  ParmVarDecl *Param = cast<ParmVarDecl>(param.getAs<Decl>());
114  UnparsedDefaultArgLocs.erase(Param);
115
116  ExprOwningPtr<Expr> DefaultArg(this, defarg.takeAs<Expr>());
117  QualType ParamType = Param->getType();
118
119  // Default arguments are only permitted in C++
120  if (!getLangOptions().CPlusPlus) {
121    Diag(EqualLoc, diag::err_param_default_argument)
122      << DefaultArg->getSourceRange();
123    Param->setInvalidDecl();
124    return;
125  }
126
127  // C++ [dcl.fct.default]p5
128  //   A default argument expression is implicitly converted (clause
129  //   4) to the parameter type. The default argument expression has
130  //   the same semantic constraints as the initializer expression in
131  //   a declaration of a variable of the parameter type, using the
132  //   copy-initialization semantics (8.5).
133  Expr *DefaultArgPtr = DefaultArg.get();
134  bool DefaultInitFailed = CheckInitializerTypes(DefaultArgPtr, ParamType,
135                                                 EqualLoc,
136                                                 Param->getDeclName(),
137                                                 /*DirectInit=*/false);
138  if (DefaultArgPtr != DefaultArg.get()) {
139    DefaultArg.take();
140    DefaultArg.reset(DefaultArgPtr);
141  }
142  if (DefaultInitFailed) {
143    return;
144  }
145
146  // Check that the default argument is well-formed
147  CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg.get(), this);
148  if (DefaultArgChecker.Visit(DefaultArg.get())) {
149    Param->setInvalidDecl();
150    return;
151  }
152
153  DefaultArgPtr = MaybeCreateCXXExprWithTemporaries(DefaultArg.take(),
154                                                    /*DestroyTemps=*/false);
155
156  // Okay: add the default argument to the parameter
157  Param->setDefaultArg(DefaultArgPtr);
158}
159
160/// ActOnParamUnparsedDefaultArgument - We've seen a default
161/// argument for a function parameter, but we can't parse it yet
162/// because we're inside a class definition. Note that this default
163/// argument will be parsed later.
164void Sema::ActOnParamUnparsedDefaultArgument(DeclPtrTy param,
165                                             SourceLocation EqualLoc,
166                                             SourceLocation ArgLoc) {
167  if (!param)
168    return;
169
170  ParmVarDecl *Param = cast<ParmVarDecl>(param.getAs<Decl>());
171  if (Param)
172    Param->setUnparsedDefaultArg();
173
174  UnparsedDefaultArgLocs[Param] = ArgLoc;
175}
176
177/// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
178/// the default argument for the parameter param failed.
179void Sema::ActOnParamDefaultArgumentError(DeclPtrTy param) {
180  if (!param)
181    return;
182
183  ParmVarDecl *Param = cast<ParmVarDecl>(param.getAs<Decl>());
184
185  Param->setInvalidDecl();
186
187  UnparsedDefaultArgLocs.erase(Param);
188}
189
190/// CheckExtraCXXDefaultArguments - Check for any extra default
191/// arguments in the declarator, which is not a function declaration
192/// or definition and therefore is not permitted to have default
193/// arguments. This routine should be invoked for every declarator
194/// that is not a function declaration or definition.
195void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
196  // C++ [dcl.fct.default]p3
197  //   A default argument expression shall be specified only in the
198  //   parameter-declaration-clause of a function declaration or in a
199  //   template-parameter (14.1). It shall not be specified for a
200  //   parameter pack. If it is specified in a
201  //   parameter-declaration-clause, it shall not occur within a
202  //   declarator or abstract-declarator of a parameter-declaration.
203  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
204    DeclaratorChunk &chunk = D.getTypeObject(i);
205    if (chunk.Kind == DeclaratorChunk::Function) {
206      for (unsigned argIdx = 0, e = chunk.Fun.NumArgs; argIdx != e; ++argIdx) {
207        ParmVarDecl *Param =
208          cast<ParmVarDecl>(chunk.Fun.ArgInfo[argIdx].Param.getAs<Decl>());
209        if (Param->hasUnparsedDefaultArg()) {
210          CachedTokens *Toks = chunk.Fun.ArgInfo[argIdx].DefaultArgTokens;
211          Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
212            << SourceRange((*Toks)[1].getLocation(), Toks->back().getLocation());
213          delete Toks;
214          chunk.Fun.ArgInfo[argIdx].DefaultArgTokens = 0;
215        } else if (Param->getDefaultArg()) {
216          Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
217            << Param->getDefaultArg()->getSourceRange();
218          Param->setDefaultArg(0);
219        }
220      }
221    }
222  }
223}
224
225// MergeCXXFunctionDecl - Merge two declarations of the same C++
226// function, once we already know that they have the same
227// type. Subroutine of MergeFunctionDecl. Returns true if there was an
228// error, false otherwise.
229bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old) {
230  bool Invalid = false;
231
232  // C++ [dcl.fct.default]p4:
233  //
234  //   For non-template functions, default arguments can be added in
235  //   later declarations of a function in the same
236  //   scope. Declarations in different scopes have completely
237  //   distinct sets of default arguments. That is, declarations in
238  //   inner scopes do not acquire default arguments from
239  //   declarations in outer scopes, and vice versa. In a given
240  //   function declaration, all parameters subsequent to a
241  //   parameter with a default argument shall have default
242  //   arguments supplied in this or previous declarations. A
243  //   default argument shall not be redefined by a later
244  //   declaration (not even to the same value).
245  for (unsigned p = 0, NumParams = Old->getNumParams(); p < NumParams; ++p) {
246    ParmVarDecl *OldParam = Old->getParamDecl(p);
247    ParmVarDecl *NewParam = New->getParamDecl(p);
248
249    if(OldParam->getDefaultArg() && NewParam->getDefaultArg()) {
250      Diag(NewParam->getLocation(),
251           diag::err_param_default_argument_redefinition)
252        << NewParam->getDefaultArg()->getSourceRange();
253      Diag(OldParam->getLocation(), diag::note_previous_definition);
254      Invalid = true;
255    } else if (OldParam->getDefaultArg()) {
256      // Merge the old default argument into the new parameter
257      NewParam->setDefaultArg(OldParam->getDefaultArg());
258    }
259  }
260
261  return Invalid;
262}
263
264/// CheckCXXDefaultArguments - Verify that the default arguments for a
265/// function declaration are well-formed according to C++
266/// [dcl.fct.default].
267void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
268  unsigned NumParams = FD->getNumParams();
269  unsigned p;
270
271  // Find first parameter with a default argument
272  for (p = 0; p < NumParams; ++p) {
273    ParmVarDecl *Param = FD->getParamDecl(p);
274    if (Param->getDefaultArg())
275      break;
276  }
277
278  // C++ [dcl.fct.default]p4:
279  //   In a given function declaration, all parameters
280  //   subsequent to a parameter with a default argument shall
281  //   have default arguments supplied in this or previous
282  //   declarations. A default argument shall not be redefined
283  //   by a later declaration (not even to the same value).
284  unsigned LastMissingDefaultArg = 0;
285  for(; p < NumParams; ++p) {
286    ParmVarDecl *Param = FD->getParamDecl(p);
287    if (!Param->getDefaultArg()) {
288      if (Param->isInvalidDecl())
289        /* We already complained about this parameter. */;
290      else if (Param->getIdentifier())
291        Diag(Param->getLocation(),
292             diag::err_param_default_argument_missing_name)
293          << Param->getIdentifier();
294      else
295        Diag(Param->getLocation(),
296             diag::err_param_default_argument_missing);
297
298      LastMissingDefaultArg = p;
299    }
300  }
301
302  if (LastMissingDefaultArg > 0) {
303    // Some default arguments were missing. Clear out all of the
304    // default arguments up to (and including) the last missing
305    // default argument, so that we leave the function parameters
306    // in a semantically valid state.
307    for (p = 0; p <= LastMissingDefaultArg; ++p) {
308      ParmVarDecl *Param = FD->getParamDecl(p);
309      if (Param->hasDefaultArg()) {
310        if (!Param->hasUnparsedDefaultArg())
311          Param->getDefaultArg()->Destroy(Context);
312        Param->setDefaultArg(0);
313      }
314    }
315  }
316}
317
318/// isCurrentClassName - Determine whether the identifier II is the
319/// name of the class type currently being defined. In the case of
320/// nested classes, this will only return true if II is the name of
321/// the innermost class.
322bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *,
323                              const CXXScopeSpec *SS) {
324  CXXRecordDecl *CurDecl;
325  if (SS && SS->isSet() && !SS->isInvalid()) {
326    DeclContext *DC = computeDeclContext(*SS);
327    CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
328  } else
329    CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
330
331  if (CurDecl)
332    return &II == CurDecl->getIdentifier();
333  else
334    return false;
335}
336
337/// \brief Check the validity of a C++ base class specifier.
338///
339/// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
340/// and returns NULL otherwise.
341CXXBaseSpecifier *
342Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
343                         SourceRange SpecifierRange,
344                         bool Virtual, AccessSpecifier Access,
345                         QualType BaseType,
346                         SourceLocation BaseLoc) {
347  // C++ [class.union]p1:
348  //   A union shall not have base classes.
349  if (Class->isUnion()) {
350    Diag(Class->getLocation(), diag::err_base_clause_on_union)
351      << SpecifierRange;
352    return 0;
353  }
354
355  if (BaseType->isDependentType())
356    return new CXXBaseSpecifier(SpecifierRange, Virtual,
357                                Class->getTagKind() == RecordDecl::TK_class,
358                                Access, BaseType);
359
360  // Base specifiers must be record types.
361  if (!BaseType->isRecordType()) {
362    Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
363    return 0;
364  }
365
366  // C++ [class.union]p1:
367  //   A union shall not be used as a base class.
368  if (BaseType->isUnionType()) {
369    Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
370    return 0;
371  }
372
373  // C++ [class.derived]p2:
374  //   The class-name in a base-specifier shall not be an incompletely
375  //   defined class.
376  if (RequireCompleteType(BaseLoc, BaseType, diag::err_incomplete_base_class,
377                          SpecifierRange))
378    return 0;
379
380  // If the base class is polymorphic, the new one is, too.
381  RecordDecl *BaseDecl = BaseType->getAsRecordType()->getDecl();
382  assert(BaseDecl && "Record type has no declaration");
383  BaseDecl = BaseDecl->getDefinition(Context);
384  assert(BaseDecl && "Base type is not incomplete, but has no definition");
385  if (cast<CXXRecordDecl>(BaseDecl)->isPolymorphic())
386    Class->setPolymorphic(true);
387
388  // C++ [dcl.init.aggr]p1:
389  //   An aggregate is [...] a class with [...] no base classes [...].
390  Class->setAggregate(false);
391  Class->setPOD(false);
392
393  if (Virtual) {
394    // C++ [class.ctor]p5:
395    //   A constructor is trivial if its class has no virtual base classes.
396    Class->setHasTrivialConstructor(false);
397  } else {
398    // C++ [class.ctor]p5:
399    //   A constructor is trivial if all the direct base classes of its
400    //   class have trivial constructors.
401    Class->setHasTrivialConstructor(cast<CXXRecordDecl>(BaseDecl)->
402                                    hasTrivialConstructor());
403  }
404
405  // C++ [class.ctor]p3:
406  //   A destructor is trivial if all the direct base classes of its class
407  //   have trivial destructors.
408  Class->setHasTrivialDestructor(cast<CXXRecordDecl>(BaseDecl)->
409                                 hasTrivialDestructor());
410
411  // Create the base specifier.
412  // FIXME: Allocate via ASTContext?
413  return new CXXBaseSpecifier(SpecifierRange, Virtual,
414                              Class->getTagKind() == RecordDecl::TK_class,
415                              Access, BaseType);
416}
417
418/// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
419/// one entry in the base class list of a class specifier, for
420/// example:
421///    class foo : public bar, virtual private baz {
422/// 'public bar' and 'virtual private baz' are each base-specifiers.
423Sema::BaseResult
424Sema::ActOnBaseSpecifier(DeclPtrTy classdecl, SourceRange SpecifierRange,
425                         bool Virtual, AccessSpecifier Access,
426                         TypeTy *basetype, SourceLocation BaseLoc) {
427  if (!classdecl)
428    return true;
429
430  AdjustDeclIfTemplate(classdecl);
431  CXXRecordDecl *Class = cast<CXXRecordDecl>(classdecl.getAs<Decl>());
432  QualType BaseType = QualType::getFromOpaquePtr(basetype);
433  if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
434                                                      Virtual, Access,
435                                                      BaseType, BaseLoc))
436    return BaseSpec;
437
438  return true;
439}
440
441/// \brief Performs the actual work of attaching the given base class
442/// specifiers to a C++ class.
443bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class, CXXBaseSpecifier **Bases,
444                                unsigned NumBases) {
445 if (NumBases == 0)
446    return false;
447
448  // Used to keep track of which base types we have already seen, so
449  // that we can properly diagnose redundant direct base types. Note
450  // that the key is always the unqualified canonical type of the base
451  // class.
452  std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
453
454  // Copy non-redundant base specifiers into permanent storage.
455  unsigned NumGoodBases = 0;
456  bool Invalid = false;
457  for (unsigned idx = 0; idx < NumBases; ++idx) {
458    QualType NewBaseType
459      = Context.getCanonicalType(Bases[idx]->getType());
460    NewBaseType = NewBaseType.getUnqualifiedType();
461
462    if (KnownBaseTypes[NewBaseType]) {
463      // C++ [class.mi]p3:
464      //   A class shall not be specified as a direct base class of a
465      //   derived class more than once.
466      Diag(Bases[idx]->getSourceRange().getBegin(),
467           diag::err_duplicate_base_class)
468        << KnownBaseTypes[NewBaseType]->getType()
469        << Bases[idx]->getSourceRange();
470
471      // Delete the duplicate base class specifier; we're going to
472      // overwrite its pointer later.
473      delete Bases[idx];
474
475      Invalid = true;
476    } else {
477      // Okay, add this new base class.
478      KnownBaseTypes[NewBaseType] = Bases[idx];
479      Bases[NumGoodBases++] = Bases[idx];
480    }
481  }
482
483  // Attach the remaining base class specifiers to the derived class.
484  Class->setBases(Bases, NumGoodBases);
485
486  // Delete the remaining (good) base class specifiers, since their
487  // data has been copied into the CXXRecordDecl.
488  for (unsigned idx = 0; idx < NumGoodBases; ++idx)
489    delete Bases[idx];
490
491  return Invalid;
492}
493
494/// ActOnBaseSpecifiers - Attach the given base specifiers to the
495/// class, after checking whether there are any duplicate base
496/// classes.
497void Sema::ActOnBaseSpecifiers(DeclPtrTy ClassDecl, BaseTy **Bases,
498                               unsigned NumBases) {
499  if (!ClassDecl || !Bases || !NumBases)
500    return;
501
502  AdjustDeclIfTemplate(ClassDecl);
503  AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl.getAs<Decl>()),
504                       (CXXBaseSpecifier**)(Bases), NumBases);
505}
506
507//===----------------------------------------------------------------------===//
508// C++ class member Handling
509//===----------------------------------------------------------------------===//
510
511/// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
512/// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
513/// bitfield width if there is one and 'InitExpr' specifies the initializer if
514/// any.
515Sema::DeclPtrTy
516Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
517                               ExprTy *BW, ExprTy *InitExpr, bool Deleted) {
518  const DeclSpec &DS = D.getDeclSpec();
519  DeclarationName Name = GetNameForDeclarator(D);
520  Expr *BitWidth = static_cast<Expr*>(BW);
521  Expr *Init = static_cast<Expr*>(InitExpr);
522  SourceLocation Loc = D.getIdentifierLoc();
523
524  bool isFunc = D.isFunctionDeclarator();
525
526  // C++ 9.2p6: A member shall not be declared to have automatic storage
527  // duration (auto, register) or with the extern storage-class-specifier.
528  // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
529  // data members and cannot be applied to names declared const or static,
530  // and cannot be applied to reference members.
531  switch (DS.getStorageClassSpec()) {
532    case DeclSpec::SCS_unspecified:
533    case DeclSpec::SCS_typedef:
534    case DeclSpec::SCS_static:
535      // FALL THROUGH.
536      break;
537    case DeclSpec::SCS_mutable:
538      if (isFunc) {
539        if (DS.getStorageClassSpecLoc().isValid())
540          Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
541        else
542          Diag(DS.getThreadSpecLoc(), diag::err_mutable_function);
543
544        // FIXME: It would be nicer if the keyword was ignored only for this
545        // declarator. Otherwise we could get follow-up errors.
546        D.getMutableDeclSpec().ClearStorageClassSpecs();
547      } else {
548        QualType T = GetTypeForDeclarator(D, S);
549        diag::kind err = static_cast<diag::kind>(0);
550        if (T->isReferenceType())
551          err = diag::err_mutable_reference;
552        else if (T.isConstQualified())
553          err = diag::err_mutable_const;
554        if (err != 0) {
555          if (DS.getStorageClassSpecLoc().isValid())
556            Diag(DS.getStorageClassSpecLoc(), err);
557          else
558            Diag(DS.getThreadSpecLoc(), err);
559          // FIXME: It would be nicer if the keyword was ignored only for this
560          // declarator. Otherwise we could get follow-up errors.
561          D.getMutableDeclSpec().ClearStorageClassSpecs();
562        }
563      }
564      break;
565    default:
566      if (DS.getStorageClassSpecLoc().isValid())
567        Diag(DS.getStorageClassSpecLoc(),
568             diag::err_storageclass_invalid_for_member);
569      else
570        Diag(DS.getThreadSpecLoc(), diag::err_storageclass_invalid_for_member);
571      D.getMutableDeclSpec().ClearStorageClassSpecs();
572  }
573
574  if (!isFunc &&
575      D.getDeclSpec().getTypeSpecType() == DeclSpec::TST_typename &&
576      D.getNumTypeObjects() == 0) {
577    // Check also for this case:
578    //
579    // typedef int f();
580    // f a;
581    //
582    QualType TDType = QualType::getFromOpaquePtr(DS.getTypeRep());
583    isFunc = TDType->isFunctionType();
584  }
585
586  bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
587                       DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
588                      !isFunc);
589
590  Decl *Member;
591  if (isInstField) {
592    Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D, BitWidth,
593                         AS);
594    assert(Member && "HandleField never returns null");
595  } else {
596    Member = ActOnDeclarator(S, D).getAs<Decl>();
597    if (!Member) {
598      if (BitWidth) DeleteExpr(BitWidth);
599      return DeclPtrTy();
600    }
601
602    // Non-instance-fields can't have a bitfield.
603    if (BitWidth) {
604      if (Member->isInvalidDecl()) {
605        // don't emit another diagnostic.
606      } else if (isa<VarDecl>(Member)) {
607        // C++ 9.6p3: A bit-field shall not be a static member.
608        // "static member 'A' cannot be a bit-field"
609        Diag(Loc, diag::err_static_not_bitfield)
610          << Name << BitWidth->getSourceRange();
611      } else if (isa<TypedefDecl>(Member)) {
612        // "typedef member 'x' cannot be a bit-field"
613        Diag(Loc, diag::err_typedef_not_bitfield)
614          << Name << BitWidth->getSourceRange();
615      } else {
616        // A function typedef ("typedef int f(); f a;").
617        // C++ 9.6p3: A bit-field shall have integral or enumeration type.
618        Diag(Loc, diag::err_not_integral_type_bitfield)
619          << Name << cast<ValueDecl>(Member)->getType()
620          << BitWidth->getSourceRange();
621      }
622
623      DeleteExpr(BitWidth);
624      BitWidth = 0;
625      Member->setInvalidDecl();
626    }
627
628    Member->setAccess(AS);
629  }
630
631  assert((Name || isInstField) && "No identifier for non-field ?");
632
633  if (Init)
634    AddInitializerToDecl(DeclPtrTy::make(Member), ExprArg(*this, Init), false);
635  if (Deleted) // FIXME: Source location is not very good.
636    SetDeclDeleted(DeclPtrTy::make(Member), D.getSourceRange().getBegin());
637
638  if (isInstField) {
639    FieldCollector->Add(cast<FieldDecl>(Member));
640    return DeclPtrTy();
641  }
642  return DeclPtrTy::make(Member);
643}
644
645/// ActOnMemInitializer - Handle a C++ member initializer.
646Sema::MemInitResult
647Sema::ActOnMemInitializer(DeclPtrTy ConstructorD,
648                          Scope *S,
649                          IdentifierInfo *MemberOrBase,
650                          SourceLocation IdLoc,
651                          SourceLocation LParenLoc,
652                          ExprTy **Args, unsigned NumArgs,
653                          SourceLocation *CommaLocs,
654                          SourceLocation RParenLoc) {
655  if (!ConstructorD)
656    return true;
657
658  CXXConstructorDecl *Constructor
659    = dyn_cast<CXXConstructorDecl>(ConstructorD.getAs<Decl>());
660  if (!Constructor) {
661    // The user wrote a constructor initializer on a function that is
662    // not a C++ constructor. Ignore the error for now, because we may
663    // have more member initializers coming; we'll diagnose it just
664    // once in ActOnMemInitializers.
665    return true;
666  }
667
668  CXXRecordDecl *ClassDecl = Constructor->getParent();
669
670  // C++ [class.base.init]p2:
671  //   Names in a mem-initializer-id are looked up in the scope of the
672  //   constructor’s class and, if not found in that scope, are looked
673  //   up in the scope containing the constructor’s
674  //   definition. [Note: if the constructor’s class contains a member
675  //   with the same name as a direct or virtual base class of the
676  //   class, a mem-initializer-id naming the member or base class and
677  //   composed of a single identifier refers to the class member. A
678  //   mem-initializer-id for the hidden base class may be specified
679  //   using a qualified name. ]
680  // Look for a member, first.
681  FieldDecl *Member = 0;
682  DeclContext::lookup_result Result
683    = ClassDecl->lookup(Context, MemberOrBase);
684  if (Result.first != Result.second)
685    Member = dyn_cast<FieldDecl>(*Result.first);
686
687  // FIXME: Handle members of an anonymous union.
688
689  if (Member) {
690    // FIXME: Perform direct initialization of the member.
691    return new CXXBaseOrMemberInitializer(Member, (Expr **)Args, NumArgs);
692  }
693
694  // It didn't name a member, so see if it names a class.
695  TypeTy *BaseTy = getTypeName(*MemberOrBase, IdLoc, S, 0/*SS*/);
696  if (!BaseTy)
697    return Diag(IdLoc, diag::err_mem_init_not_member_or_class)
698      << MemberOrBase << SourceRange(IdLoc, RParenLoc);
699
700  QualType BaseType = QualType::getFromOpaquePtr(BaseTy);
701  if (!BaseType->isRecordType())
702    return Diag(IdLoc, diag::err_base_init_does_not_name_class)
703      << BaseType << SourceRange(IdLoc, RParenLoc);
704
705  // C++ [class.base.init]p2:
706  //   [...] Unless the mem-initializer-id names a nonstatic data
707  //   member of the constructor’s class or a direct or virtual base
708  //   of that class, the mem-initializer is ill-formed. A
709  //   mem-initializer-list can initialize a base class using any
710  //   name that denotes that base class type.
711
712  // First, check for a direct base class.
713  const CXXBaseSpecifier *DirectBaseSpec = 0;
714  for (CXXRecordDecl::base_class_const_iterator Base = ClassDecl->bases_begin();
715       Base != ClassDecl->bases_end(); ++Base) {
716    if (Context.getCanonicalType(BaseType).getUnqualifiedType() ==
717        Context.getCanonicalType(Base->getType()).getUnqualifiedType()) {
718      // We found a direct base of this type. That's what we're
719      // initializing.
720      DirectBaseSpec = &*Base;
721      break;
722    }
723  }
724
725  // Check for a virtual base class.
726  // FIXME: We might be able to short-circuit this if we know in advance that
727  // there are no virtual bases.
728  const CXXBaseSpecifier *VirtualBaseSpec = 0;
729  if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
730    // We haven't found a base yet; search the class hierarchy for a
731    // virtual base class.
732    BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
733                    /*DetectVirtual=*/false);
734    if (IsDerivedFrom(Context.getTypeDeclType(ClassDecl), BaseType, Paths)) {
735      for (BasePaths::paths_iterator Path = Paths.begin();
736           Path != Paths.end(); ++Path) {
737        if (Path->back().Base->isVirtual()) {
738          VirtualBaseSpec = Path->back().Base;
739          break;
740        }
741      }
742    }
743  }
744
745  // C++ [base.class.init]p2:
746  //   If a mem-initializer-id is ambiguous because it designates both
747  //   a direct non-virtual base class and an inherited virtual base
748  //   class, the mem-initializer is ill-formed.
749  if (DirectBaseSpec && VirtualBaseSpec)
750    return Diag(IdLoc, diag::err_base_init_direct_and_virtual)
751      << MemberOrBase << SourceRange(IdLoc, RParenLoc);
752
753  return new CXXBaseOrMemberInitializer(BaseType, (Expr **)Args, NumArgs);
754}
755
756void Sema::ActOnMemInitializers(DeclPtrTy ConstructorDecl,
757                                SourceLocation ColonLoc,
758                                MemInitTy **MemInits, unsigned NumMemInits) {
759  if (!ConstructorDecl)
760    return;
761
762  CXXConstructorDecl *Constructor
763    = dyn_cast<CXXConstructorDecl>(ConstructorDecl.getAs<Decl>());
764
765  if (!Constructor) {
766    Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
767    return;
768  }
769}
770
771namespace {
772  /// PureVirtualMethodCollector - traverses a class and its superclasses
773  /// and determines if it has any pure virtual methods.
774  class VISIBILITY_HIDDEN PureVirtualMethodCollector {
775    ASTContext &Context;
776
777  public:
778    typedef llvm::SmallVector<const CXXMethodDecl*, 8> MethodList;
779
780  private:
781    MethodList Methods;
782
783    void Collect(const CXXRecordDecl* RD, MethodList& Methods);
784
785  public:
786    PureVirtualMethodCollector(ASTContext &Ctx, const CXXRecordDecl* RD)
787      : Context(Ctx) {
788
789      MethodList List;
790      Collect(RD, List);
791
792      // Copy the temporary list to methods, and make sure to ignore any
793      // null entries.
794      for (size_t i = 0, e = List.size(); i != e; ++i) {
795        if (List[i])
796          Methods.push_back(List[i]);
797      }
798    }
799
800    bool empty() const { return Methods.empty(); }
801
802    MethodList::const_iterator methods_begin() { return Methods.begin(); }
803    MethodList::const_iterator methods_end() { return Methods.end(); }
804  };
805
806  void PureVirtualMethodCollector::Collect(const CXXRecordDecl* RD,
807                                           MethodList& Methods) {
808    // First, collect the pure virtual methods for the base classes.
809    for (CXXRecordDecl::base_class_const_iterator Base = RD->bases_begin(),
810         BaseEnd = RD->bases_end(); Base != BaseEnd; ++Base) {
811      if (const RecordType *RT = Base->getType()->getAsRecordType()) {
812        const CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(RT->getDecl());
813        if (BaseDecl && BaseDecl->isAbstract())
814          Collect(BaseDecl, Methods);
815      }
816    }
817
818    // Next, zero out any pure virtual methods that this class overrides.
819    typedef llvm::SmallPtrSet<const CXXMethodDecl*, 4> MethodSetTy;
820
821    MethodSetTy OverriddenMethods;
822    size_t MethodsSize = Methods.size();
823
824    for (RecordDecl::decl_iterator i = RD->decls_begin(Context),
825         e = RD->decls_end(Context);
826         i != e; ++i) {
827      // Traverse the record, looking for methods.
828      if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(*i)) {
829        // If the method is pre virtual, add it to the methods vector.
830        if (MD->isPure()) {
831          Methods.push_back(MD);
832          continue;
833        }
834
835        // Otherwise, record all the overridden methods in our set.
836        for (CXXMethodDecl::method_iterator I = MD->begin_overridden_methods(),
837             E = MD->end_overridden_methods(); I != E; ++I) {
838          // Keep track of the overridden methods.
839          OverriddenMethods.insert(*I);
840        }
841      }
842    }
843
844    // Now go through the methods and zero out all the ones we know are
845    // overridden.
846    for (size_t i = 0, e = MethodsSize; i != e; ++i) {
847      if (OverriddenMethods.count(Methods[i]))
848        Methods[i] = 0;
849    }
850
851  }
852}
853
854bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
855                                  unsigned DiagID, AbstractDiagSelID SelID,
856                                  const CXXRecordDecl *CurrentRD) {
857
858  if (!getLangOptions().CPlusPlus)
859    return false;
860
861  if (const ArrayType *AT = Context.getAsArrayType(T))
862    return RequireNonAbstractType(Loc, AT->getElementType(), DiagID, SelID,
863                                  CurrentRD);
864
865  if (const PointerType *PT = T->getAsPointerType()) {
866    // Find the innermost pointer type.
867    while (const PointerType *T = PT->getPointeeType()->getAsPointerType())
868      PT = T;
869
870    if (const ArrayType *AT = Context.getAsArrayType(PT->getPointeeType()))
871      return RequireNonAbstractType(Loc, AT->getElementType(), DiagID, SelID,
872                                    CurrentRD);
873  }
874
875  const RecordType *RT = T->getAsRecordType();
876  if (!RT)
877    return false;
878
879  const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl());
880  if (!RD)
881    return false;
882
883  if (CurrentRD && CurrentRD != RD)
884    return false;
885
886  if (!RD->isAbstract())
887    return false;
888
889  Diag(Loc, DiagID) << RD->getDeclName() << SelID;
890
891  // Check if we've already emitted the list of pure virtual functions for this
892  // class.
893  if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
894    return true;
895
896  PureVirtualMethodCollector Collector(Context, RD);
897
898  for (PureVirtualMethodCollector::MethodList::const_iterator I =
899       Collector.methods_begin(), E = Collector.methods_end(); I != E; ++I) {
900    const CXXMethodDecl *MD = *I;
901
902    Diag(MD->getLocation(), diag::note_pure_virtual_function) <<
903      MD->getDeclName();
904  }
905
906  if (!PureVirtualClassDiagSet)
907    PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
908  PureVirtualClassDiagSet->insert(RD);
909
910  return true;
911}
912
913namespace {
914  class VISIBILITY_HIDDEN AbstractClassUsageDiagnoser
915    : public DeclVisitor<AbstractClassUsageDiagnoser, bool> {
916    Sema &SemaRef;
917    CXXRecordDecl *AbstractClass;
918
919    bool VisitDeclContext(const DeclContext *DC) {
920      bool Invalid = false;
921
922      for (CXXRecordDecl::decl_iterator I = DC->decls_begin(SemaRef.Context),
923           E = DC->decls_end(SemaRef.Context); I != E; ++I)
924        Invalid |= Visit(*I);
925
926      return Invalid;
927    }
928
929  public:
930    AbstractClassUsageDiagnoser(Sema& SemaRef, CXXRecordDecl *ac)
931      : SemaRef(SemaRef), AbstractClass(ac) {
932        Visit(SemaRef.Context.getTranslationUnitDecl());
933    }
934
935    bool VisitFunctionDecl(const FunctionDecl *FD) {
936      if (FD->isThisDeclarationADefinition()) {
937        // No need to do the check if we're in a definition, because it requires
938        // that the return/param types are complete.
939        // because that requires
940        return VisitDeclContext(FD);
941      }
942
943      // Check the return type.
944      QualType RTy = FD->getType()->getAsFunctionType()->getResultType();
945      bool Invalid =
946        SemaRef.RequireNonAbstractType(FD->getLocation(), RTy,
947                                       diag::err_abstract_type_in_decl,
948                                       Sema::AbstractReturnType,
949                                       AbstractClass);
950
951      for (FunctionDecl::param_const_iterator I = FD->param_begin(),
952           E = FD->param_end(); I != E; ++I) {
953        const ParmVarDecl *VD = *I;
954        Invalid |=
955          SemaRef.RequireNonAbstractType(VD->getLocation(),
956                                         VD->getOriginalType(),
957                                         diag::err_abstract_type_in_decl,
958                                         Sema::AbstractParamType,
959                                         AbstractClass);
960      }
961
962      return Invalid;
963    }
964
965    bool VisitDecl(const Decl* D) {
966      if (const DeclContext *DC = dyn_cast<DeclContext>(D))
967        return VisitDeclContext(DC);
968
969      return false;
970    }
971  };
972}
973
974void Sema::ActOnFinishCXXMemberSpecification(Scope* S, SourceLocation RLoc,
975                                             DeclPtrTy TagDecl,
976                                             SourceLocation LBrac,
977                                             SourceLocation RBrac) {
978  if (!TagDecl)
979    return;
980
981  AdjustDeclIfTemplate(TagDecl);
982  ActOnFields(S, RLoc, TagDecl,
983              (DeclPtrTy*)FieldCollector->getCurFields(),
984              FieldCollector->getCurNumFields(), LBrac, RBrac, 0);
985
986  CXXRecordDecl *RD = cast<CXXRecordDecl>(TagDecl.getAs<Decl>());
987  if (!RD->isAbstract()) {
988    // Collect all the pure virtual methods and see if this is an abstract
989    // class after all.
990    PureVirtualMethodCollector Collector(Context, RD);
991    if (!Collector.empty())
992      RD->setAbstract(true);
993  }
994
995  if (RD->isAbstract())
996    AbstractClassUsageDiagnoser(*this, RD);
997
998  if (RD->hasTrivialConstructor() || RD->hasTrivialDestructor()) {
999    for (RecordDecl::field_iterator i = RD->field_begin(Context),
1000         e = RD->field_end(Context); i != e; ++i) {
1001      // All the nonstatic data members must have trivial constructors.
1002      QualType FTy = i->getType();
1003      while (const ArrayType *AT = Context.getAsArrayType(FTy))
1004        FTy = AT->getElementType();
1005
1006      if (const RecordType *RT = FTy->getAsRecordType()) {
1007        CXXRecordDecl *FieldRD = cast<CXXRecordDecl>(RT->getDecl());
1008
1009        if (!FieldRD->hasTrivialConstructor())
1010          RD->setHasTrivialConstructor(false);
1011        if (!FieldRD->hasTrivialDestructor())
1012          RD->setHasTrivialDestructor(false);
1013
1014        // If RD has neither a trivial constructor nor a trivial destructor
1015        // we don't need to continue checking.
1016        if (!RD->hasTrivialConstructor() && !RD->hasTrivialDestructor())
1017          break;
1018      }
1019    }
1020  }
1021
1022  if (!RD->isDependentType())
1023    AddImplicitlyDeclaredMembersToClass(RD);
1024}
1025
1026/// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared
1027/// special functions, such as the default constructor, copy
1028/// constructor, or destructor, to the given C++ class (C++
1029/// [special]p1).  This routine can only be executed just before the
1030/// definition of the class is complete.
1031void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) {
1032  QualType ClassType = Context.getTypeDeclType(ClassDecl);
1033  ClassType = Context.getCanonicalType(ClassType);
1034
1035  // FIXME: Implicit declarations have exception specifications, which are
1036  // the union of the specifications of the implicitly called functions.
1037
1038  if (!ClassDecl->hasUserDeclaredConstructor()) {
1039    // C++ [class.ctor]p5:
1040    //   A default constructor for a class X is a constructor of class X
1041    //   that can be called without an argument. If there is no
1042    //   user-declared constructor for class X, a default constructor is
1043    //   implicitly declared. An implicitly-declared default constructor
1044    //   is an inline public member of its class.
1045    DeclarationName Name
1046      = Context.DeclarationNames.getCXXConstructorName(ClassType);
1047    CXXConstructorDecl *DefaultCon =
1048      CXXConstructorDecl::Create(Context, ClassDecl,
1049                                 ClassDecl->getLocation(), Name,
1050                                 Context.getFunctionType(Context.VoidTy,
1051                                                         0, 0, false, 0),
1052                                 /*isExplicit=*/false,
1053                                 /*isInline=*/true,
1054                                 /*isImplicitlyDeclared=*/true);
1055    DefaultCon->setAccess(AS_public);
1056    DefaultCon->setImplicit();
1057    ClassDecl->addDecl(Context, DefaultCon);
1058  }
1059
1060  if (!ClassDecl->hasUserDeclaredCopyConstructor()) {
1061    // C++ [class.copy]p4:
1062    //   If the class definition does not explicitly declare a copy
1063    //   constructor, one is declared implicitly.
1064
1065    // C++ [class.copy]p5:
1066    //   The implicitly-declared copy constructor for a class X will
1067    //   have the form
1068    //
1069    //       X::X(const X&)
1070    //
1071    //   if
1072    bool HasConstCopyConstructor = true;
1073
1074    //     -- each direct or virtual base class B of X has a copy
1075    //        constructor whose first parameter is of type const B& or
1076    //        const volatile B&, and
1077    for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin();
1078         HasConstCopyConstructor && Base != ClassDecl->bases_end(); ++Base) {
1079      const CXXRecordDecl *BaseClassDecl
1080        = cast<CXXRecordDecl>(Base->getType()->getAsRecordType()->getDecl());
1081      HasConstCopyConstructor
1082        = BaseClassDecl->hasConstCopyConstructor(Context);
1083    }
1084
1085    //     -- for all the nonstatic data members of X that are of a
1086    //        class type M (or array thereof), each such class type
1087    //        has a copy constructor whose first parameter is of type
1088    //        const M& or const volatile M&.
1089    for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(Context);
1090         HasConstCopyConstructor && Field != ClassDecl->field_end(Context);
1091         ++Field) {
1092      QualType FieldType = (*Field)->getType();
1093      if (const ArrayType *Array = Context.getAsArrayType(FieldType))
1094        FieldType = Array->getElementType();
1095      if (const RecordType *FieldClassType = FieldType->getAsRecordType()) {
1096        const CXXRecordDecl *FieldClassDecl
1097          = cast<CXXRecordDecl>(FieldClassType->getDecl());
1098        HasConstCopyConstructor
1099          = FieldClassDecl->hasConstCopyConstructor(Context);
1100      }
1101    }
1102
1103    //   Otherwise, the implicitly declared copy constructor will have
1104    //   the form
1105    //
1106    //       X::X(X&)
1107    QualType ArgType = ClassType;
1108    if (HasConstCopyConstructor)
1109      ArgType = ArgType.withConst();
1110    ArgType = Context.getLValueReferenceType(ArgType);
1111
1112    //   An implicitly-declared copy constructor is an inline public
1113    //   member of its class.
1114    DeclarationName Name
1115      = Context.DeclarationNames.getCXXConstructorName(ClassType);
1116    CXXConstructorDecl *CopyConstructor
1117      = CXXConstructorDecl::Create(Context, ClassDecl,
1118                                   ClassDecl->getLocation(), Name,
1119                                   Context.getFunctionType(Context.VoidTy,
1120                                                           &ArgType, 1,
1121                                                           false, 0),
1122                                   /*isExplicit=*/false,
1123                                   /*isInline=*/true,
1124                                   /*isImplicitlyDeclared=*/true);
1125    CopyConstructor->setAccess(AS_public);
1126    CopyConstructor->setImplicit();
1127
1128    // Add the parameter to the constructor.
1129    ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyConstructor,
1130                                                 ClassDecl->getLocation(),
1131                                                 /*IdentifierInfo=*/0,
1132                                                 ArgType, VarDecl::None, 0);
1133    CopyConstructor->setParams(Context, &FromParam, 1);
1134    ClassDecl->addDecl(Context, CopyConstructor);
1135  }
1136
1137  if (!ClassDecl->hasUserDeclaredCopyAssignment()) {
1138    // Note: The following rules are largely analoguous to the copy
1139    // constructor rules. Note that virtual bases are not taken into account
1140    // for determining the argument type of the operator. Note also that
1141    // operators taking an object instead of a reference are allowed.
1142    //
1143    // C++ [class.copy]p10:
1144    //   If the class definition does not explicitly declare a copy
1145    //   assignment operator, one is declared implicitly.
1146    //   The implicitly-defined copy assignment operator for a class X
1147    //   will have the form
1148    //
1149    //       X& X::operator=(const X&)
1150    //
1151    //   if
1152    bool HasConstCopyAssignment = true;
1153
1154    //       -- each direct base class B of X has a copy assignment operator
1155    //          whose parameter is of type const B&, const volatile B& or B,
1156    //          and
1157    for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin();
1158         HasConstCopyAssignment && Base != ClassDecl->bases_end(); ++Base) {
1159      const CXXRecordDecl *BaseClassDecl
1160        = cast<CXXRecordDecl>(Base->getType()->getAsRecordType()->getDecl());
1161      HasConstCopyAssignment = BaseClassDecl->hasConstCopyAssignment(Context);
1162    }
1163
1164    //       -- for all the nonstatic data members of X that are of a class
1165    //          type M (or array thereof), each such class type has a copy
1166    //          assignment operator whose parameter is of type const M&,
1167    //          const volatile M& or M.
1168    for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(Context);
1169         HasConstCopyAssignment && Field != ClassDecl->field_end(Context);
1170         ++Field) {
1171      QualType FieldType = (*Field)->getType();
1172      if (const ArrayType *Array = Context.getAsArrayType(FieldType))
1173        FieldType = Array->getElementType();
1174      if (const RecordType *FieldClassType = FieldType->getAsRecordType()) {
1175        const CXXRecordDecl *FieldClassDecl
1176          = cast<CXXRecordDecl>(FieldClassType->getDecl());
1177        HasConstCopyAssignment
1178          = FieldClassDecl->hasConstCopyAssignment(Context);
1179      }
1180    }
1181
1182    //   Otherwise, the implicitly declared copy assignment operator will
1183    //   have the form
1184    //
1185    //       X& X::operator=(X&)
1186    QualType ArgType = ClassType;
1187    QualType RetType = Context.getLValueReferenceType(ArgType);
1188    if (HasConstCopyAssignment)
1189      ArgType = ArgType.withConst();
1190    ArgType = Context.getLValueReferenceType(ArgType);
1191
1192    //   An implicitly-declared copy assignment operator is an inline public
1193    //   member of its class.
1194    DeclarationName Name =
1195      Context.DeclarationNames.getCXXOperatorName(OO_Equal);
1196    CXXMethodDecl *CopyAssignment =
1197      CXXMethodDecl::Create(Context, ClassDecl, ClassDecl->getLocation(), Name,
1198                            Context.getFunctionType(RetType, &ArgType, 1,
1199                                                    false, 0),
1200                            /*isStatic=*/false, /*isInline=*/true);
1201    CopyAssignment->setAccess(AS_public);
1202    CopyAssignment->setImplicit();
1203
1204    // Add the parameter to the operator.
1205    ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment,
1206                                                 ClassDecl->getLocation(),
1207                                                 /*IdentifierInfo=*/0,
1208                                                 ArgType, VarDecl::None, 0);
1209    CopyAssignment->setParams(Context, &FromParam, 1);
1210
1211    // Don't call addedAssignmentOperator. There is no way to distinguish an
1212    // implicit from an explicit assignment operator.
1213    ClassDecl->addDecl(Context, CopyAssignment);
1214  }
1215
1216  if (!ClassDecl->hasUserDeclaredDestructor()) {
1217    // C++ [class.dtor]p2:
1218    //   If a class has no user-declared destructor, a destructor is
1219    //   declared implicitly. An implicitly-declared destructor is an
1220    //   inline public member of its class.
1221    DeclarationName Name
1222      = Context.DeclarationNames.getCXXDestructorName(ClassType);
1223    CXXDestructorDecl *Destructor
1224      = CXXDestructorDecl::Create(Context, ClassDecl,
1225                                  ClassDecl->getLocation(), Name,
1226                                  Context.getFunctionType(Context.VoidTy,
1227                                                          0, 0, false, 0),
1228                                  /*isInline=*/true,
1229                                  /*isImplicitlyDeclared=*/true);
1230    Destructor->setAccess(AS_public);
1231    Destructor->setImplicit();
1232    ClassDecl->addDecl(Context, Destructor);
1233  }
1234}
1235
1236void Sema::ActOnReenterTemplateScope(Scope *S, DeclPtrTy TemplateD) {
1237  TemplateDecl *Template = TemplateD.getAs<TemplateDecl>();
1238  if (!Template)
1239    return;
1240
1241  TemplateParameterList *Params = Template->getTemplateParameters();
1242  for (TemplateParameterList::iterator Param = Params->begin(),
1243                                    ParamEnd = Params->end();
1244       Param != ParamEnd; ++Param) {
1245    NamedDecl *Named = cast<NamedDecl>(*Param);
1246    if (Named->getDeclName()) {
1247      S->AddDecl(DeclPtrTy::make(Named));
1248      IdResolver.AddDecl(Named);
1249    }
1250  }
1251}
1252
1253/// ActOnStartDelayedCXXMethodDeclaration - We have completed
1254/// parsing a top-level (non-nested) C++ class, and we are now
1255/// parsing those parts of the given Method declaration that could
1256/// not be parsed earlier (C++ [class.mem]p2), such as default
1257/// arguments. This action should enter the scope of the given
1258/// Method declaration as if we had just parsed the qualified method
1259/// name. However, it should not bring the parameters into scope;
1260/// that will be performed by ActOnDelayedCXXMethodParameter.
1261void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, DeclPtrTy MethodD) {
1262  if (!MethodD)
1263    return;
1264
1265  CXXScopeSpec SS;
1266  FunctionDecl *Method = cast<FunctionDecl>(MethodD.getAs<Decl>());
1267  QualType ClassTy
1268    = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
1269  SS.setScopeRep(
1270    NestedNameSpecifier::Create(Context, 0, false, ClassTy.getTypePtr()));
1271  ActOnCXXEnterDeclaratorScope(S, SS);
1272}
1273
1274/// ActOnDelayedCXXMethodParameter - We've already started a delayed
1275/// C++ method declaration. We're (re-)introducing the given
1276/// function parameter into scope for use in parsing later parts of
1277/// the method declaration. For example, we could see an
1278/// ActOnParamDefaultArgument event for this parameter.
1279void Sema::ActOnDelayedCXXMethodParameter(Scope *S, DeclPtrTy ParamD) {
1280  if (!ParamD)
1281    return;
1282
1283  ParmVarDecl *Param = cast<ParmVarDecl>(ParamD.getAs<Decl>());
1284
1285  // If this parameter has an unparsed default argument, clear it out
1286  // to make way for the parsed default argument.
1287  if (Param->hasUnparsedDefaultArg())
1288    Param->setDefaultArg(0);
1289
1290  S->AddDecl(DeclPtrTy::make(Param));
1291  if (Param->getDeclName())
1292    IdResolver.AddDecl(Param);
1293}
1294
1295/// ActOnFinishDelayedCXXMethodDeclaration - We have finished
1296/// processing the delayed method declaration for Method. The method
1297/// declaration is now considered finished. There may be a separate
1298/// ActOnStartOfFunctionDef action later (not necessarily
1299/// immediately!) for this method, if it was also defined inside the
1300/// class body.
1301void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, DeclPtrTy MethodD) {
1302  if (!MethodD)
1303    return;
1304
1305  FunctionDecl *Method = cast<FunctionDecl>(MethodD.getAs<Decl>());
1306  CXXScopeSpec SS;
1307  QualType ClassTy
1308    = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
1309  SS.setScopeRep(
1310    NestedNameSpecifier::Create(Context, 0, false, ClassTy.getTypePtr()));
1311  ActOnCXXExitDeclaratorScope(S, SS);
1312
1313  // Now that we have our default arguments, check the constructor
1314  // again. It could produce additional diagnostics or affect whether
1315  // the class has implicitly-declared destructors, among other
1316  // things.
1317  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method))
1318    CheckConstructor(Constructor);
1319
1320  // Check the default arguments, which we may have added.
1321  if (!Method->isInvalidDecl())
1322    CheckCXXDefaultArguments(Method);
1323}
1324
1325/// CheckConstructorDeclarator - Called by ActOnDeclarator to check
1326/// the well-formedness of the constructor declarator @p D with type @p
1327/// R. If there are any errors in the declarator, this routine will
1328/// emit diagnostics and set the invalid bit to true.  In any case, the type
1329/// will be updated to reflect a well-formed type for the constructor and
1330/// returned.
1331QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R,
1332                                          FunctionDecl::StorageClass &SC) {
1333  bool isVirtual = D.getDeclSpec().isVirtualSpecified();
1334
1335  // C++ [class.ctor]p3:
1336  //   A constructor shall not be virtual (10.3) or static (9.4). A
1337  //   constructor can be invoked for a const, volatile or const
1338  //   volatile object. A constructor shall not be declared const,
1339  //   volatile, or const volatile (9.3.2).
1340  if (isVirtual) {
1341    if (!D.isInvalidType())
1342      Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
1343        << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc())
1344        << SourceRange(D.getIdentifierLoc());
1345    D.setInvalidType();
1346  }
1347  if (SC == FunctionDecl::Static) {
1348    if (!D.isInvalidType())
1349      Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
1350        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
1351        << SourceRange(D.getIdentifierLoc());
1352    D.setInvalidType();
1353    SC = FunctionDecl::None;
1354  }
1355
1356  DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
1357  if (FTI.TypeQuals != 0) {
1358    if (FTI.TypeQuals & QualType::Const)
1359      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
1360        << "const" << SourceRange(D.getIdentifierLoc());
1361    if (FTI.TypeQuals & QualType::Volatile)
1362      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
1363        << "volatile" << SourceRange(D.getIdentifierLoc());
1364    if (FTI.TypeQuals & QualType::Restrict)
1365      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
1366        << "restrict" << SourceRange(D.getIdentifierLoc());
1367  }
1368
1369  // Rebuild the function type "R" without any type qualifiers (in
1370  // case any of the errors above fired) and with "void" as the
1371  // return type, since constructors don't have return types. We
1372  // *always* have to do this, because GetTypeForDeclarator will
1373  // put in a result type of "int" when none was specified.
1374  const FunctionProtoType *Proto = R->getAsFunctionProtoType();
1375  return Context.getFunctionType(Context.VoidTy, Proto->arg_type_begin(),
1376                                 Proto->getNumArgs(),
1377                                 Proto->isVariadic(), 0);
1378}
1379
1380/// CheckConstructor - Checks a fully-formed constructor for
1381/// well-formedness, issuing any diagnostics required. Returns true if
1382/// the constructor declarator is invalid.
1383void Sema::CheckConstructor(CXXConstructorDecl *Constructor) {
1384  CXXRecordDecl *ClassDecl
1385    = dyn_cast<CXXRecordDecl>(Constructor->getDeclContext());
1386  if (!ClassDecl)
1387    return Constructor->setInvalidDecl();
1388
1389  // C++ [class.copy]p3:
1390  //   A declaration of a constructor for a class X is ill-formed if
1391  //   its first parameter is of type (optionally cv-qualified) X and
1392  //   either there are no other parameters or else all other
1393  //   parameters have default arguments.
1394  if (!Constructor->isInvalidDecl() &&
1395      ((Constructor->getNumParams() == 1) ||
1396       (Constructor->getNumParams() > 1 &&
1397        Constructor->getParamDecl(1)->hasDefaultArg()))) {
1398    QualType ParamType = Constructor->getParamDecl(0)->getType();
1399    QualType ClassTy = Context.getTagDeclType(ClassDecl);
1400    if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) {
1401      SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation();
1402      Diag(ParamLoc, diag::err_constructor_byvalue_arg)
1403        << CodeModificationHint::CreateInsertion(ParamLoc, " const &");
1404      Constructor->setInvalidDecl();
1405    }
1406  }
1407
1408  // Notify the class that we've added a constructor.
1409  ClassDecl->addedConstructor(Context, Constructor);
1410}
1411
1412static inline bool
1413FTIHasSingleVoidArgument(DeclaratorChunk::FunctionTypeInfo &FTI) {
1414  return (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 &&
1415          FTI.ArgInfo[0].Param &&
1416          FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType()->isVoidType());
1417}
1418
1419/// CheckDestructorDeclarator - Called by ActOnDeclarator to check
1420/// the well-formednes of the destructor declarator @p D with type @p
1421/// R. If there are any errors in the declarator, this routine will
1422/// emit diagnostics and set the declarator to invalid.  Even if this happens,
1423/// will be updated to reflect a well-formed type for the destructor and
1424/// returned.
1425QualType Sema::CheckDestructorDeclarator(Declarator &D,
1426                                         FunctionDecl::StorageClass& SC) {
1427  // C++ [class.dtor]p1:
1428  //   [...] A typedef-name that names a class is a class-name
1429  //   (7.1.3); however, a typedef-name that names a class shall not
1430  //   be used as the identifier in the declarator for a destructor
1431  //   declaration.
1432  QualType DeclaratorType = QualType::getFromOpaquePtr(D.getDeclaratorIdType());
1433  if (isa<TypedefType>(DeclaratorType)) {
1434    Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name)
1435      << DeclaratorType;
1436    D.setInvalidType();
1437  }
1438
1439  // C++ [class.dtor]p2:
1440  //   A destructor is used to destroy objects of its class type. A
1441  //   destructor takes no parameters, and no return type can be
1442  //   specified for it (not even void). The address of a destructor
1443  //   shall not be taken. A destructor shall not be static. A
1444  //   destructor can be invoked for a const, volatile or const
1445  //   volatile object. A destructor shall not be declared const,
1446  //   volatile or const volatile (9.3.2).
1447  if (SC == FunctionDecl::Static) {
1448    if (!D.isInvalidType())
1449      Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be)
1450        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
1451        << SourceRange(D.getIdentifierLoc());
1452    SC = FunctionDecl::None;
1453    D.setInvalidType();
1454  }
1455  if (D.getDeclSpec().hasTypeSpecifier() && !D.isInvalidType()) {
1456    // Destructors don't have return types, but the parser will
1457    // happily parse something like:
1458    //
1459    //   class X {
1460    //     float ~X();
1461    //   };
1462    //
1463    // The return type will be eliminated later.
1464    Diag(D.getIdentifierLoc(), diag::err_destructor_return_type)
1465      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
1466      << SourceRange(D.getIdentifierLoc());
1467  }
1468
1469  DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
1470  if (FTI.TypeQuals != 0 && !D.isInvalidType()) {
1471    if (FTI.TypeQuals & QualType::Const)
1472      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
1473        << "const" << SourceRange(D.getIdentifierLoc());
1474    if (FTI.TypeQuals & QualType::Volatile)
1475      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
1476        << "volatile" << SourceRange(D.getIdentifierLoc());
1477    if (FTI.TypeQuals & QualType::Restrict)
1478      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
1479        << "restrict" << SourceRange(D.getIdentifierLoc());
1480    D.setInvalidType();
1481  }
1482
1483  // Make sure we don't have any parameters.
1484  if (FTI.NumArgs > 0 && !FTIHasSingleVoidArgument(FTI)) {
1485    Diag(D.getIdentifierLoc(), diag::err_destructor_with_params);
1486
1487    // Delete the parameters.
1488    FTI.freeArgs();
1489    D.setInvalidType();
1490  }
1491
1492  // Make sure the destructor isn't variadic.
1493  if (FTI.isVariadic) {
1494    Diag(D.getIdentifierLoc(), diag::err_destructor_variadic);
1495    D.setInvalidType();
1496  }
1497
1498  // Rebuild the function type "R" without any type qualifiers or
1499  // parameters (in case any of the errors above fired) and with
1500  // "void" as the return type, since destructors don't have return
1501  // types. We *always* have to do this, because GetTypeForDeclarator
1502  // will put in a result type of "int" when none was specified.
1503  return Context.getFunctionType(Context.VoidTy, 0, 0, false, 0);
1504}
1505
1506/// CheckConversionDeclarator - Called by ActOnDeclarator to check the
1507/// well-formednes of the conversion function declarator @p D with
1508/// type @p R. If there are any errors in the declarator, this routine
1509/// will emit diagnostics and return true. Otherwise, it will return
1510/// false. Either way, the type @p R will be updated to reflect a
1511/// well-formed type for the conversion operator.
1512void Sema::CheckConversionDeclarator(Declarator &D, QualType &R,
1513                                     FunctionDecl::StorageClass& SC) {
1514  // C++ [class.conv.fct]p1:
1515  //   Neither parameter types nor return type can be specified. The
1516  //   type of a conversion function (8.3.5) is “function taking no
1517  //   parameter returning conversion-type-id.”
1518  if (SC == FunctionDecl::Static) {
1519    if (!D.isInvalidType())
1520      Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member)
1521        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
1522        << SourceRange(D.getIdentifierLoc());
1523    D.setInvalidType();
1524    SC = FunctionDecl::None;
1525  }
1526  if (D.getDeclSpec().hasTypeSpecifier() && !D.isInvalidType()) {
1527    // Conversion functions don't have return types, but the parser will
1528    // happily parse something like:
1529    //
1530    //   class X {
1531    //     float operator bool();
1532    //   };
1533    //
1534    // The return type will be changed later anyway.
1535    Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type)
1536      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
1537      << SourceRange(D.getIdentifierLoc());
1538  }
1539
1540  // Make sure we don't have any parameters.
1541  if (R->getAsFunctionProtoType()->getNumArgs() > 0) {
1542    Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params);
1543
1544    // Delete the parameters.
1545    D.getTypeObject(0).Fun.freeArgs();
1546    D.setInvalidType();
1547  }
1548
1549  // Make sure the conversion function isn't variadic.
1550  if (R->getAsFunctionProtoType()->isVariadic() && !D.isInvalidType()) {
1551    Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic);
1552    D.setInvalidType();
1553  }
1554
1555  // C++ [class.conv.fct]p4:
1556  //   The conversion-type-id shall not represent a function type nor
1557  //   an array type.
1558  QualType ConvType = QualType::getFromOpaquePtr(D.getDeclaratorIdType());
1559  if (ConvType->isArrayType()) {
1560    Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array);
1561    ConvType = Context.getPointerType(ConvType);
1562    D.setInvalidType();
1563  } else if (ConvType->isFunctionType()) {
1564    Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function);
1565    ConvType = Context.getPointerType(ConvType);
1566    D.setInvalidType();
1567  }
1568
1569  // Rebuild the function type "R" without any parameters (in case any
1570  // of the errors above fired) and with the conversion type as the
1571  // return type.
1572  R = Context.getFunctionType(ConvType, 0, 0, false,
1573                              R->getAsFunctionProtoType()->getTypeQuals());
1574
1575  // C++0x explicit conversion operators.
1576  if (D.getDeclSpec().isExplicitSpecified() && !getLangOptions().CPlusPlus0x)
1577    Diag(D.getDeclSpec().getExplicitSpecLoc(),
1578         diag::warn_explicit_conversion_functions)
1579      << SourceRange(D.getDeclSpec().getExplicitSpecLoc());
1580}
1581
1582/// ActOnConversionDeclarator - Called by ActOnDeclarator to complete
1583/// the declaration of the given C++ conversion function. This routine
1584/// is responsible for recording the conversion function in the C++
1585/// class, if possible.
1586Sema::DeclPtrTy Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) {
1587  assert(Conversion && "Expected to receive a conversion function declaration");
1588
1589  // Set the lexical context of this conversion function
1590  Conversion->setLexicalDeclContext(CurContext);
1591
1592  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext());
1593
1594  // Make sure we aren't redeclaring the conversion function.
1595  QualType ConvType = Context.getCanonicalType(Conversion->getConversionType());
1596
1597  // C++ [class.conv.fct]p1:
1598  //   [...] A conversion function is never used to convert a
1599  //   (possibly cv-qualified) object to the (possibly cv-qualified)
1600  //   same object type (or a reference to it), to a (possibly
1601  //   cv-qualified) base class of that type (or a reference to it),
1602  //   or to (possibly cv-qualified) void.
1603  // FIXME: Suppress this warning if the conversion function ends up being a
1604  // virtual function that overrides a virtual function in a base class.
1605  QualType ClassType
1606    = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
1607  if (const ReferenceType *ConvTypeRef = ConvType->getAsReferenceType())
1608    ConvType = ConvTypeRef->getPointeeType();
1609  if (ConvType->isRecordType()) {
1610    ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType();
1611    if (ConvType == ClassType)
1612      Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used)
1613        << ClassType;
1614    else if (IsDerivedFrom(ClassType, ConvType))
1615      Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used)
1616        <<  ClassType << ConvType;
1617  } else if (ConvType->isVoidType()) {
1618    Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used)
1619      << ClassType << ConvType;
1620  }
1621
1622  if (Conversion->getPreviousDeclaration()) {
1623    OverloadedFunctionDecl *Conversions = ClassDecl->getConversionFunctions();
1624    for (OverloadedFunctionDecl::function_iterator
1625           Conv = Conversions->function_begin(),
1626           ConvEnd = Conversions->function_end();
1627         Conv != ConvEnd; ++Conv) {
1628      if (*Conv == Conversion->getPreviousDeclaration()) {
1629        *Conv = Conversion;
1630        return DeclPtrTy::make(Conversion);
1631      }
1632    }
1633    assert(Conversion->isInvalidDecl() && "Conversion should not get here.");
1634  } else
1635    ClassDecl->addConversionFunction(Context, Conversion);
1636
1637  return DeclPtrTy::make(Conversion);
1638}
1639
1640//===----------------------------------------------------------------------===//
1641// Namespace Handling
1642//===----------------------------------------------------------------------===//
1643
1644/// ActOnStartNamespaceDef - This is called at the start of a namespace
1645/// definition.
1646Sema::DeclPtrTy Sema::ActOnStartNamespaceDef(Scope *NamespcScope,
1647                                             SourceLocation IdentLoc,
1648                                             IdentifierInfo *II,
1649                                             SourceLocation LBrace) {
1650  NamespaceDecl *Namespc =
1651      NamespaceDecl::Create(Context, CurContext, IdentLoc, II);
1652  Namespc->setLBracLoc(LBrace);
1653
1654  Scope *DeclRegionScope = NamespcScope->getParent();
1655
1656  if (II) {
1657    // C++ [namespace.def]p2:
1658    // The identifier in an original-namespace-definition shall not have been
1659    // previously defined in the declarative region in which the
1660    // original-namespace-definition appears. The identifier in an
1661    // original-namespace-definition is the name of the namespace. Subsequently
1662    // in that declarative region, it is treated as an original-namespace-name.
1663
1664    NamedDecl *PrevDecl = LookupName(DeclRegionScope, II, LookupOrdinaryName,
1665                                     true);
1666
1667    if (NamespaceDecl *OrigNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl)) {
1668      // This is an extended namespace definition.
1669      // Attach this namespace decl to the chain of extended namespace
1670      // definitions.
1671      OrigNS->setNextNamespace(Namespc);
1672      Namespc->setOriginalNamespace(OrigNS->getOriginalNamespace());
1673
1674      // Remove the previous declaration from the scope.
1675      if (DeclRegionScope->isDeclScope(DeclPtrTy::make(OrigNS))) {
1676        IdResolver.RemoveDecl(OrigNS);
1677        DeclRegionScope->RemoveDecl(DeclPtrTy::make(OrigNS));
1678      }
1679    } else if (PrevDecl) {
1680      // This is an invalid name redefinition.
1681      Diag(Namespc->getLocation(), diag::err_redefinition_different_kind)
1682       << Namespc->getDeclName();
1683      Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1684      Namespc->setInvalidDecl();
1685      // Continue on to push Namespc as current DeclContext and return it.
1686    }
1687
1688    PushOnScopeChains(Namespc, DeclRegionScope);
1689  } else {
1690    // FIXME: Handle anonymous namespaces
1691  }
1692
1693  // Although we could have an invalid decl (i.e. the namespace name is a
1694  // redefinition), push it as current DeclContext and try to continue parsing.
1695  // FIXME: We should be able to push Namespc here, so that the each DeclContext
1696  // for the namespace has the declarations that showed up in that particular
1697  // namespace definition.
1698  PushDeclContext(NamespcScope, Namespc);
1699  return DeclPtrTy::make(Namespc);
1700}
1701
1702/// ActOnFinishNamespaceDef - This callback is called after a namespace is
1703/// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef.
1704void Sema::ActOnFinishNamespaceDef(DeclPtrTy D, SourceLocation RBrace) {
1705  Decl *Dcl = D.getAs<Decl>();
1706  NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl);
1707  assert(Namespc && "Invalid parameter, expected NamespaceDecl");
1708  Namespc->setRBracLoc(RBrace);
1709  PopDeclContext();
1710}
1711
1712Sema::DeclPtrTy Sema::ActOnUsingDirective(Scope *S,
1713                                          SourceLocation UsingLoc,
1714                                          SourceLocation NamespcLoc,
1715                                          const CXXScopeSpec &SS,
1716                                          SourceLocation IdentLoc,
1717                                          IdentifierInfo *NamespcName,
1718                                          AttributeList *AttrList) {
1719  assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
1720  assert(NamespcName && "Invalid NamespcName.");
1721  assert(IdentLoc.isValid() && "Invalid NamespceName location.");
1722  assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
1723
1724  UsingDirectiveDecl *UDir = 0;
1725
1726  // Lookup namespace name.
1727  LookupResult R = LookupParsedName(S, &SS, NamespcName,
1728                                    LookupNamespaceName, false);
1729  if (R.isAmbiguous()) {
1730    DiagnoseAmbiguousLookup(R, NamespcName, IdentLoc);
1731    return DeclPtrTy();
1732  }
1733  if (NamedDecl *NS = R) {
1734    assert(isa<NamespaceDecl>(NS) && "expected namespace decl");
1735    // C++ [namespace.udir]p1:
1736    //   A using-directive specifies that the names in the nominated
1737    //   namespace can be used in the scope in which the
1738    //   using-directive appears after the using-directive. During
1739    //   unqualified name lookup (3.4.1), the names appear as if they
1740    //   were declared in the nearest enclosing namespace which
1741    //   contains both the using-directive and the nominated
1742    //   namespace. [Note: in this context, “contains” means “contains
1743    //   directly or indirectly”. ]
1744
1745    // Find enclosing context containing both using-directive and
1746    // nominated namespace.
1747    DeclContext *CommonAncestor = cast<DeclContext>(NS);
1748    while (CommonAncestor && !CommonAncestor->Encloses(CurContext))
1749      CommonAncestor = CommonAncestor->getParent();
1750
1751    UDir = UsingDirectiveDecl::Create(Context,
1752                                      CurContext, UsingLoc,
1753                                      NamespcLoc,
1754                                      SS.getRange(),
1755                                      (NestedNameSpecifier *)SS.getScopeRep(),
1756                                      IdentLoc,
1757                                      cast<NamespaceDecl>(NS),
1758                                      CommonAncestor);
1759    PushUsingDirective(S, UDir);
1760  } else {
1761    Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
1762  }
1763
1764  // FIXME: We ignore attributes for now.
1765  delete AttrList;
1766  return DeclPtrTy::make(UDir);
1767}
1768
1769void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) {
1770  // If scope has associated entity, then using directive is at namespace
1771  // or translation unit scope. We add UsingDirectiveDecls, into
1772  // it's lookup structure.
1773  if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity()))
1774    Ctx->addDecl(Context, UDir);
1775  else
1776    // Otherwise it is block-sope. using-directives will affect lookup
1777    // only to the end of scope.
1778    S->PushUsingDirective(DeclPtrTy::make(UDir));
1779}
1780
1781
1782Sema::DeclPtrTy Sema::ActOnUsingDeclaration(Scope *S,
1783                                          SourceLocation UsingLoc,
1784                                          const CXXScopeSpec &SS,
1785                                          SourceLocation IdentLoc,
1786                                          IdentifierInfo *TargetName,
1787                                          AttributeList *AttrList,
1788                                          bool IsTypeName) {
1789  assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
1790  assert(TargetName && "Invalid TargetName.");
1791  assert(IdentLoc.isValid() && "Invalid TargetName location.");
1792  assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
1793
1794  UsingDecl *UsingAlias = 0;
1795
1796  // Lookup target name.
1797  LookupResult R = LookupParsedName(S, &SS, TargetName,
1798                                    LookupOrdinaryName, false);
1799
1800  if (NamedDecl *NS = R) {
1801    if (IsTypeName && !isa<TypeDecl>(NS)) {
1802      Diag(IdentLoc, diag::err_using_typename_non_type);
1803    }
1804    UsingAlias = UsingDecl::Create(Context, CurContext, IdentLoc, SS.getRange(),
1805        NS->getLocation(), UsingLoc, NS,
1806        static_cast<NestedNameSpecifier *>(SS.getScopeRep()),
1807        IsTypeName);
1808    PushOnScopeChains(UsingAlias, S);
1809  } else {
1810    Diag(IdentLoc, diag::err_using_requires_qualname) << SS.getRange();
1811  }
1812
1813  // FIXME: We ignore attributes for now.
1814  delete AttrList;
1815  return DeclPtrTy::make(UsingAlias);
1816}
1817
1818/// getNamespaceDecl - Returns the namespace a decl represents. If the decl
1819/// is a namespace alias, returns the namespace it points to.
1820static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) {
1821  if (NamespaceAliasDecl *AD = dyn_cast_or_null<NamespaceAliasDecl>(D))
1822    return AD->getNamespace();
1823  return dyn_cast_or_null<NamespaceDecl>(D);
1824}
1825
1826Sema::DeclPtrTy Sema::ActOnNamespaceAliasDef(Scope *S,
1827                                             SourceLocation NamespaceLoc,
1828                                             SourceLocation AliasLoc,
1829                                             IdentifierInfo *Alias,
1830                                             const CXXScopeSpec &SS,
1831                                             SourceLocation IdentLoc,
1832                                             IdentifierInfo *Ident) {
1833
1834  // Lookup the namespace name.
1835  LookupResult R = LookupParsedName(S, &SS, Ident, LookupNamespaceName, false);
1836
1837  // Check if we have a previous declaration with the same name.
1838  if (NamedDecl *PrevDecl = LookupName(S, Alias, LookupOrdinaryName, true)) {
1839    if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) {
1840      // We already have an alias with the same name that points to the same
1841      // namespace, so don't create a new one.
1842      if (!R.isAmbiguous() && AD->getNamespace() == getNamespaceDecl(R))
1843        return DeclPtrTy();
1844    }
1845
1846    unsigned DiagID = isa<NamespaceDecl>(PrevDecl) ? diag::err_redefinition :
1847      diag::err_redefinition_different_kind;
1848    Diag(AliasLoc, DiagID) << Alias;
1849    Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1850    return DeclPtrTy();
1851  }
1852
1853  if (R.isAmbiguous()) {
1854    DiagnoseAmbiguousLookup(R, Ident, IdentLoc);
1855    return DeclPtrTy();
1856  }
1857
1858  if (!R) {
1859    Diag(NamespaceLoc, diag::err_expected_namespace_name) << SS.getRange();
1860    return DeclPtrTy();
1861  }
1862
1863  NamespaceAliasDecl *AliasDecl =
1864    NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc,
1865                               Alias, SS.getRange(),
1866                               (NestedNameSpecifier *)SS.getScopeRep(),
1867                               IdentLoc, R);
1868
1869  CurContext->addDecl(Context, AliasDecl);
1870  return DeclPtrTy::make(AliasDecl);
1871}
1872
1873void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
1874                                            CXXConstructorDecl *Constructor) {
1875  assert((Constructor->isImplicit() && Constructor->isDefaultConstructor() &&
1876          !Constructor->isUsed()) &&
1877    "DefineImplicitDefaultConstructor - call it for implicit default ctor");
1878
1879  CXXRecordDecl *ClassDecl
1880    = cast<CXXRecordDecl>(Constructor->getDeclContext());
1881  assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor");
1882  // Before the implicitly-declared default constructor for a class is
1883  // implicitly defined, all the implicitly-declared default constructors
1884  // for its base class and its non-static data members shall have been
1885  // implicitly defined.
1886  bool err = false;
1887  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin();
1888       Base != ClassDecl->bases_end(); ++Base) {
1889    CXXRecordDecl *BaseClassDecl
1890      = cast<CXXRecordDecl>(Base->getType()->getAsRecordType()->getDecl());
1891    if (!BaseClassDecl->hasTrivialConstructor()) {
1892      if (CXXConstructorDecl *BaseCtor =
1893            BaseClassDecl->getDefaultConstructor(Context))
1894        MarkDeclarationReferenced(CurrentLocation, BaseCtor);
1895      else {
1896        Diag(CurrentLocation, diag::err_defining_default_ctor)
1897          << Context.getTagDeclType(ClassDecl) << 1
1898          << Context.getTagDeclType(BaseClassDecl);
1899        Diag(BaseClassDecl->getLocation(), diag::note_previous_class_decl)
1900              << Context.getTagDeclType(BaseClassDecl);
1901        err = true;
1902      }
1903    }
1904  }
1905  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(Context);
1906       Field != ClassDecl->field_end(Context);
1907       ++Field) {
1908    QualType FieldType = Context.getCanonicalType((*Field)->getType());
1909    if (const ArrayType *Array = Context.getAsArrayType(FieldType))
1910      FieldType = Array->getElementType();
1911    if (const RecordType *FieldClassType = FieldType->getAsRecordType()) {
1912      CXXRecordDecl *FieldClassDecl
1913        = cast<CXXRecordDecl>(FieldClassType->getDecl());
1914      if (!FieldClassDecl->hasTrivialConstructor()) {
1915        if (CXXConstructorDecl *FieldCtor =
1916            FieldClassDecl->getDefaultConstructor(Context))
1917          MarkDeclarationReferenced(CurrentLocation, FieldCtor);
1918        else {
1919          Diag(CurrentLocation, diag::err_defining_default_ctor)
1920          << Context.getTagDeclType(ClassDecl) << 0 <<
1921              Context.getTagDeclType(FieldClassDecl);
1922          Diag(FieldClassDecl->getLocation(), diag::note_previous_class_decl)
1923          << Context.getTagDeclType(FieldClassDecl);
1924          err = true;
1925        }
1926      }
1927    }
1928    else if (FieldType->isReferenceType()) {
1929      Diag(CurrentLocation, diag::err_unintialized_member)
1930        << Context.getTagDeclType(ClassDecl) << 0 << (*Field)->getNameAsCString();
1931      Diag((*Field)->getLocation(), diag::note_declared_at);
1932      err = true;
1933    }
1934    else if (FieldType.isConstQualified()) {
1935      Diag(CurrentLocation, diag::err_unintialized_member)
1936        << Context.getTagDeclType(ClassDecl) << 1 << (*Field)->getNameAsCString();
1937       Diag((*Field)->getLocation(), diag::note_declared_at);
1938      err = true;
1939    }
1940  }
1941  if (!err)
1942    Constructor->setUsed();
1943}
1944
1945void Sema::DefineImplicitOverloadedAssign(SourceLocation CurrentLocation,
1946                                          CXXMethodDecl *MethodDecl) {
1947  assert((MethodDecl->isImplicit() && MethodDecl->isOverloadedOperator() &&
1948          MethodDecl->getOverloadedOperator() == OO_Equal &&
1949          !MethodDecl->isUsed()) &&
1950         "DefineImplicitOverloadedAssign - call it for implicit assignment op");
1951
1952  CXXRecordDecl *ClassDecl
1953    = cast<CXXRecordDecl>(MethodDecl->getDeclContext());
1954  assert(ClassDecl && "DefineImplicitOverloadedAssign - invalid constructor");
1955
1956  // C++[class.copy] p210
1957  // Before the implicitly-declared copy assignment operator for a class is
1958  // implicitly defined, all implicitly-declared copy assignment operators
1959  // for its direct base classes and its nonstatic data members shall have
1960  // been implicitly defined.
1961  bool err = false;
1962  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin();
1963       Base != ClassDecl->bases_end(); ++Base) {
1964    CXXRecordDecl *BaseClassDecl
1965      = cast<CXXRecordDecl>(Base->getType()->getAsRecordType()->getDecl());
1966    if (CXXMethodDecl *BaseAssignOpMethod =
1967          getAssignOperatorMethod(MethodDecl->getParamDecl(0), BaseClassDecl))
1968      MarkDeclarationReferenced(CurrentLocation, BaseAssignOpMethod);
1969  }
1970  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(Context);
1971       Field != ClassDecl->field_end(Context);
1972       ++Field) {
1973    QualType FieldType = Context.getCanonicalType((*Field)->getType());
1974    if (const ArrayType *Array = Context.getAsArrayType(FieldType))
1975      FieldType = Array->getElementType();
1976    if (const RecordType *FieldClassType = FieldType->getAsRecordType()) {
1977      CXXRecordDecl *FieldClassDecl
1978        = cast<CXXRecordDecl>(FieldClassType->getDecl());
1979      if (CXXMethodDecl *FieldAssignOpMethod =
1980          getAssignOperatorMethod(MethodDecl->getParamDecl(0), FieldClassDecl))
1981        MarkDeclarationReferenced(CurrentLocation, FieldAssignOpMethod);
1982    }
1983    else if (FieldType->isReferenceType()) {
1984      Diag(ClassDecl->getLocation(), diag::err_unintialized_member_for_assign)
1985      << Context.getTagDeclType(ClassDecl) << 0 << (*Field)->getNameAsCString();
1986      Diag((*Field)->getLocation(), diag::note_declared_at);
1987      Diag(CurrentLocation, diag::note_first_required_here);
1988      err = true;
1989    }
1990    else if (FieldType.isConstQualified()) {
1991      Diag(ClassDecl->getLocation(), diag::err_unintialized_member_for_assign)
1992      << Context.getTagDeclType(ClassDecl) << 1 << (*Field)->getNameAsCString();
1993      Diag((*Field)->getLocation(), diag::note_declared_at);
1994      Diag(CurrentLocation, diag::note_first_required_here);
1995      err = true;
1996    }
1997  }
1998  if (!err)
1999    MethodDecl->setUsed();
2000}
2001
2002CXXMethodDecl *
2003Sema::getAssignOperatorMethod(ParmVarDecl *ParmDecl,
2004                              CXXRecordDecl *ClassDecl) {
2005  QualType LHSType = Context.getTypeDeclType(ClassDecl);
2006  QualType RHSType(LHSType);
2007  // If class's assignment operator argument is const/volatile qualified,
2008  // look for operator = (const/volatile B&). Otherwise, look for
2009  // operator = (B&).
2010  if (ParmDecl->getType().isConstQualified())
2011    RHSType.addConst();
2012  if (ParmDecl->getType().isVolatileQualified())
2013    RHSType.addVolatile();
2014  ExprOwningPtr<Expr> LHS(this,  new (Context) DeclRefExpr(ParmDecl,
2015                                                          LHSType,
2016                                                          SourceLocation()));
2017  ExprOwningPtr<Expr> RHS(this,  new (Context) DeclRefExpr(ParmDecl,
2018                                                          RHSType,
2019                                                          SourceLocation()));
2020  Expr *Args[2] = { &*LHS, &*RHS };
2021  OverloadCandidateSet CandidateSet;
2022  AddMemberOperatorCandidates(clang::OO_Equal, SourceLocation(), Args, 2,
2023                              CandidateSet);
2024  OverloadCandidateSet::iterator Best;
2025  if (BestViableFunction(CandidateSet,
2026                         ClassDecl->getLocation(), Best) == OR_Success)
2027    return cast<CXXMethodDecl>(Best->Function);
2028  assert(false &&
2029         "getAssignOperatorMethod - copy assignment operator method not found");
2030  return 0;
2031}
2032
2033void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
2034                                   CXXConstructorDecl *CopyConstructor,
2035                                   unsigned TypeQuals) {
2036  assert((CopyConstructor->isImplicit() &&
2037          CopyConstructor->isCopyConstructor(Context, TypeQuals) &&
2038          !CopyConstructor->isUsed()) &&
2039         "DefineImplicitCopyConstructor - call it for implicit copy ctor");
2040
2041  CXXRecordDecl *ClassDecl
2042    = cast<CXXRecordDecl>(CopyConstructor->getDeclContext());
2043  assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor");
2044  // C++ [class.copy] p209
2045  // Before the implicitly-declared copy constructor for a class is
2046  // implicitly defined, all the implicitly-declared copy constructors
2047  // for its base class and its non-static data members shall have been
2048  // implicitly defined.
2049  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin();
2050       Base != ClassDecl->bases_end(); ++Base) {
2051    CXXRecordDecl *BaseClassDecl
2052      = cast<CXXRecordDecl>(Base->getType()->getAsRecordType()->getDecl());
2053    if (CXXConstructorDecl *BaseCopyCtor =
2054        BaseClassDecl->getCopyConstructor(Context, TypeQuals))
2055      MarkDeclarationReferenced(CurrentLocation, BaseCopyCtor);
2056  }
2057  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(Context);
2058       Field != ClassDecl->field_end(Context);
2059       ++Field) {
2060    QualType FieldType = Context.getCanonicalType((*Field)->getType());
2061    if (const ArrayType *Array = Context.getAsArrayType(FieldType))
2062      FieldType = Array->getElementType();
2063    if (const RecordType *FieldClassType = FieldType->getAsRecordType()) {
2064      CXXRecordDecl *FieldClassDecl
2065        = cast<CXXRecordDecl>(FieldClassType->getDecl());
2066      if (CXXConstructorDecl *FieldCopyCtor =
2067          FieldClassDecl->getCopyConstructor(Context, TypeQuals))
2068        MarkDeclarationReferenced(CurrentLocation, FieldCopyCtor);
2069    }
2070  }
2071  CopyConstructor->setUsed();
2072}
2073
2074void Sema::InitializeVarWithConstructor(VarDecl *VD,
2075                                        CXXConstructorDecl *Constructor,
2076                                        QualType DeclInitType,
2077                                        Expr **Exprs, unsigned NumExprs) {
2078  Expr *Temp = CXXConstructExpr::Create(Context, DeclInitType, Constructor,
2079                                        false, Exprs, NumExprs);
2080  MarkDeclarationReferenced(VD->getLocation(), Constructor);
2081  VD->setInit(Context, Temp);
2082}
2083
2084/// AddCXXDirectInitializerToDecl - This action is called immediately after
2085/// ActOnDeclarator, when a C++ direct initializer is present.
2086/// e.g: "int x(1);"
2087void Sema::AddCXXDirectInitializerToDecl(DeclPtrTy Dcl,
2088                                         SourceLocation LParenLoc,
2089                                         MultiExprArg Exprs,
2090                                         SourceLocation *CommaLocs,
2091                                         SourceLocation RParenLoc) {
2092  unsigned NumExprs = Exprs.size();
2093  assert(NumExprs != 0 && Exprs.get() && "missing expressions");
2094  Decl *RealDecl = Dcl.getAs<Decl>();
2095
2096  // If there is no declaration, there was an error parsing it.  Just ignore
2097  // the initializer.
2098  if (RealDecl == 0)
2099    return;
2100
2101  VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl);
2102  if (!VDecl) {
2103    Diag(RealDecl->getLocation(), diag::err_illegal_initializer);
2104    RealDecl->setInvalidDecl();
2105    return;
2106  }
2107
2108  // FIXME: Need to handle dependent types and expressions here.
2109
2110  // We will treat direct-initialization as a copy-initialization:
2111  //    int x(1);  -as-> int x = 1;
2112  //    ClassType x(a,b,c); -as-> ClassType x = ClassType(a,b,c);
2113  //
2114  // Clients that want to distinguish between the two forms, can check for
2115  // direct initializer using VarDecl::hasCXXDirectInitializer().
2116  // A major benefit is that clients that don't particularly care about which
2117  // exactly form was it (like the CodeGen) can handle both cases without
2118  // special case code.
2119
2120  // C++ 8.5p11:
2121  // The form of initialization (using parentheses or '=') is generally
2122  // insignificant, but does matter when the entity being initialized has a
2123  // class type.
2124  QualType DeclInitType = VDecl->getType();
2125  if (const ArrayType *Array = Context.getAsArrayType(DeclInitType))
2126    DeclInitType = Array->getElementType();
2127
2128  // FIXME: This isn't the right place to complete the type.
2129  if (RequireCompleteType(VDecl->getLocation(), VDecl->getType(),
2130                          diag::err_typecheck_decl_incomplete_type)) {
2131    VDecl->setInvalidDecl();
2132    return;
2133  }
2134
2135  if (VDecl->getType()->isRecordType()) {
2136    CXXConstructorDecl *Constructor
2137      = PerformInitializationByConstructor(DeclInitType,
2138                                           (Expr **)Exprs.get(), NumExprs,
2139                                           VDecl->getLocation(),
2140                                           SourceRange(VDecl->getLocation(),
2141                                                       RParenLoc),
2142                                           VDecl->getDeclName(),
2143                                           IK_Direct);
2144    if (!Constructor)
2145      RealDecl->setInvalidDecl();
2146    else {
2147      VDecl->setCXXDirectInitializer(true);
2148      InitializeVarWithConstructor(VDecl, Constructor, DeclInitType,
2149                                   (Expr**)Exprs.release(), NumExprs);
2150    }
2151    return;
2152  }
2153
2154  if (NumExprs > 1) {
2155    Diag(CommaLocs[0], diag::err_builtin_direct_init_more_than_one_arg)
2156      << SourceRange(VDecl->getLocation(), RParenLoc);
2157    RealDecl->setInvalidDecl();
2158    return;
2159  }
2160
2161  // Let clients know that initialization was done with a direct initializer.
2162  VDecl->setCXXDirectInitializer(true);
2163
2164  assert(NumExprs == 1 && "Expected 1 expression");
2165  // Set the init expression, handles conversions.
2166  AddInitializerToDecl(Dcl, ExprArg(*this, Exprs.release()[0]),
2167                       /*DirectInit=*/true);
2168}
2169
2170/// PerformInitializationByConstructor - Perform initialization by
2171/// constructor (C++ [dcl.init]p14), which may occur as part of
2172/// direct-initialization or copy-initialization. We are initializing
2173/// an object of type @p ClassType with the given arguments @p
2174/// Args. @p Loc is the location in the source code where the
2175/// initializer occurs (e.g., a declaration, member initializer,
2176/// functional cast, etc.) while @p Range covers the whole
2177/// initialization. @p InitEntity is the entity being initialized,
2178/// which may by the name of a declaration or a type. @p Kind is the
2179/// kind of initialization we're performing, which affects whether
2180/// explicit constructors will be considered. When successful, returns
2181/// the constructor that will be used to perform the initialization;
2182/// when the initialization fails, emits a diagnostic and returns
2183/// null.
2184CXXConstructorDecl *
2185Sema::PerformInitializationByConstructor(QualType ClassType,
2186                                         Expr **Args, unsigned NumArgs,
2187                                         SourceLocation Loc, SourceRange Range,
2188                                         DeclarationName InitEntity,
2189                                         InitializationKind Kind) {
2190  const RecordType *ClassRec = ClassType->getAsRecordType();
2191  assert(ClassRec && "Can only initialize a class type here");
2192
2193  // C++ [dcl.init]p14:
2194  //
2195  //   If the initialization is direct-initialization, or if it is
2196  //   copy-initialization where the cv-unqualified version of the
2197  //   source type is the same class as, or a derived class of, the
2198  //   class of the destination, constructors are considered. The
2199  //   applicable constructors are enumerated (13.3.1.3), and the
2200  //   best one is chosen through overload resolution (13.3). The
2201  //   constructor so selected is called to initialize the object,
2202  //   with the initializer expression(s) as its argument(s). If no
2203  //   constructor applies, or the overload resolution is ambiguous,
2204  //   the initialization is ill-formed.
2205  const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl());
2206  OverloadCandidateSet CandidateSet;
2207
2208  // Add constructors to the overload set.
2209  DeclarationName ConstructorName
2210    = Context.DeclarationNames.getCXXConstructorName(
2211                       Context.getCanonicalType(ClassType.getUnqualifiedType()));
2212  DeclContext::lookup_const_iterator Con, ConEnd;
2213  for (llvm::tie(Con, ConEnd) = ClassDecl->lookup(Context, ConstructorName);
2214       Con != ConEnd; ++Con) {
2215    CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con);
2216    if ((Kind == IK_Direct) ||
2217        (Kind == IK_Copy && Constructor->isConvertingConstructor()) ||
2218        (Kind == IK_Default && Constructor->isDefaultConstructor()))
2219      AddOverloadCandidate(Constructor, Args, NumArgs, CandidateSet);
2220  }
2221
2222  // FIXME: When we decide not to synthesize the implicitly-declared
2223  // constructors, we'll need to make them appear here.
2224
2225  OverloadCandidateSet::iterator Best;
2226  switch (BestViableFunction(CandidateSet, Loc, Best)) {
2227  case OR_Success:
2228    // We found a constructor. Return it.
2229    return cast<CXXConstructorDecl>(Best->Function);
2230
2231  case OR_No_Viable_Function:
2232    if (InitEntity)
2233      Diag(Loc, diag::err_ovl_no_viable_function_in_init)
2234        << InitEntity << Range;
2235    else
2236      Diag(Loc, diag::err_ovl_no_viable_function_in_init)
2237        << ClassType << Range;
2238    PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false);
2239    return 0;
2240
2241  case OR_Ambiguous:
2242    if (InitEntity)
2243      Diag(Loc, diag::err_ovl_ambiguous_init) << InitEntity << Range;
2244    else
2245      Diag(Loc, diag::err_ovl_ambiguous_init) << ClassType << Range;
2246    PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true);
2247    return 0;
2248
2249  case OR_Deleted:
2250    if (InitEntity)
2251      Diag(Loc, diag::err_ovl_deleted_init)
2252        << Best->Function->isDeleted()
2253        << InitEntity << Range;
2254    else
2255      Diag(Loc, diag::err_ovl_deleted_init)
2256        << Best->Function->isDeleted()
2257        << InitEntity << Range;
2258    PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true);
2259    return 0;
2260  }
2261
2262  return 0;
2263}
2264
2265/// CompareReferenceRelationship - Compare the two types T1 and T2 to
2266/// determine whether they are reference-related,
2267/// reference-compatible, reference-compatible with added
2268/// qualification, or incompatible, for use in C++ initialization by
2269/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
2270/// type, and the first type (T1) is the pointee type of the reference
2271/// type being initialized.
2272Sema::ReferenceCompareResult
2273Sema::CompareReferenceRelationship(QualType T1, QualType T2,
2274                                   bool& DerivedToBase) {
2275  assert(!T1->isReferenceType() &&
2276    "T1 must be the pointee type of the reference type");
2277  assert(!T2->isReferenceType() && "T2 cannot be a reference type");
2278
2279  T1 = Context.getCanonicalType(T1);
2280  T2 = Context.getCanonicalType(T2);
2281  QualType UnqualT1 = T1.getUnqualifiedType();
2282  QualType UnqualT2 = T2.getUnqualifiedType();
2283
2284  // C++ [dcl.init.ref]p4:
2285  //   Given types “cv1 T1” and “cv2 T2,” “cv1 T1” is
2286  //   reference-related to “cv2 T2” if T1 is the same type as T2, or
2287  //   T1 is a base class of T2.
2288  if (UnqualT1 == UnqualT2)
2289    DerivedToBase = false;
2290  else if (IsDerivedFrom(UnqualT2, UnqualT1))
2291    DerivedToBase = true;
2292  else
2293    return Ref_Incompatible;
2294
2295  // At this point, we know that T1 and T2 are reference-related (at
2296  // least).
2297
2298  // C++ [dcl.init.ref]p4:
2299  //   "cv1 T1” is reference-compatible with “cv2 T2” if T1 is
2300  //   reference-related to T2 and cv1 is the same cv-qualification
2301  //   as, or greater cv-qualification than, cv2. For purposes of
2302  //   overload resolution, cases for which cv1 is greater
2303  //   cv-qualification than cv2 are identified as
2304  //   reference-compatible with added qualification (see 13.3.3.2).
2305  if (T1.getCVRQualifiers() == T2.getCVRQualifiers())
2306    return Ref_Compatible;
2307  else if (T1.isMoreQualifiedThan(T2))
2308    return Ref_Compatible_With_Added_Qualification;
2309  else
2310    return Ref_Related;
2311}
2312
2313/// CheckReferenceInit - Check the initialization of a reference
2314/// variable with the given initializer (C++ [dcl.init.ref]). Init is
2315/// the initializer (either a simple initializer or an initializer
2316/// list), and DeclType is the type of the declaration. When ICS is
2317/// non-null, this routine will compute the implicit conversion
2318/// sequence according to C++ [over.ics.ref] and will not produce any
2319/// diagnostics; when ICS is null, it will emit diagnostics when any
2320/// errors are found. Either way, a return value of true indicates
2321/// that there was a failure, a return value of false indicates that
2322/// the reference initialization succeeded.
2323///
2324/// When @p SuppressUserConversions, user-defined conversions are
2325/// suppressed.
2326/// When @p AllowExplicit, we also permit explicit user-defined
2327/// conversion functions.
2328/// When @p ForceRValue, we unconditionally treat the initializer as an rvalue.
2329bool
2330Sema::CheckReferenceInit(Expr *&Init, QualType DeclType,
2331                         ImplicitConversionSequence *ICS,
2332                         bool SuppressUserConversions,
2333                         bool AllowExplicit, bool ForceRValue) {
2334  assert(DeclType->isReferenceType() && "Reference init needs a reference");
2335
2336  QualType T1 = DeclType->getAsReferenceType()->getPointeeType();
2337  QualType T2 = Init->getType();
2338
2339  // If the initializer is the address of an overloaded function, try
2340  // to resolve the overloaded function. If all goes well, T2 is the
2341  // type of the resulting function.
2342  if (Context.getCanonicalType(T2) == Context.OverloadTy) {
2343    FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Init, DeclType,
2344                                                          ICS != 0);
2345    if (Fn) {
2346      // Since we're performing this reference-initialization for
2347      // real, update the initializer with the resulting function.
2348      if (!ICS) {
2349        if (DiagnoseUseOfDecl(Fn, Init->getSourceRange().getBegin()))
2350          return true;
2351
2352        FixOverloadedFunctionReference(Init, Fn);
2353      }
2354
2355      T2 = Fn->getType();
2356    }
2357  }
2358
2359  // Compute some basic properties of the types and the initializer.
2360  bool isRValRef = DeclType->isRValueReferenceType();
2361  bool DerivedToBase = false;
2362  Expr::isLvalueResult InitLvalue = ForceRValue ? Expr::LV_InvalidExpression :
2363                                                  Init->isLvalue(Context);
2364  ReferenceCompareResult RefRelationship
2365    = CompareReferenceRelationship(T1, T2, DerivedToBase);
2366
2367  // Most paths end in a failed conversion.
2368  if (ICS)
2369    ICS->ConversionKind = ImplicitConversionSequence::BadConversion;
2370
2371  // C++ [dcl.init.ref]p5:
2372  //   A reference to type “cv1 T1” is initialized by an expression
2373  //   of type “cv2 T2” as follows:
2374
2375  //     -- If the initializer expression
2376
2377  // Rvalue references cannot bind to lvalues (N2812).
2378  // There is absolutely no situation where they can. In particular, note that
2379  // this is ill-formed, even if B has a user-defined conversion to A&&:
2380  //   B b;
2381  //   A&& r = b;
2382  if (isRValRef && InitLvalue == Expr::LV_Valid) {
2383    if (!ICS)
2384      Diag(Init->getSourceRange().getBegin(), diag::err_lvalue_to_rvalue_ref)
2385        << Init->getSourceRange();
2386    return true;
2387  }
2388
2389  bool BindsDirectly = false;
2390  //       -- is an lvalue (but is not a bit-field), and “cv1 T1” is
2391  //          reference-compatible with “cv2 T2,” or
2392  //
2393  // Note that the bit-field check is skipped if we are just computing
2394  // the implicit conversion sequence (C++ [over.best.ics]p2).
2395  if (InitLvalue == Expr::LV_Valid && (ICS || !Init->getBitField()) &&
2396      RefRelationship >= Ref_Compatible_With_Added_Qualification) {
2397    BindsDirectly = true;
2398
2399    if (ICS) {
2400      // C++ [over.ics.ref]p1:
2401      //   When a parameter of reference type binds directly (8.5.3)
2402      //   to an argument expression, the implicit conversion sequence
2403      //   is the identity conversion, unless the argument expression
2404      //   has a type that is a derived class of the parameter type,
2405      //   in which case the implicit conversion sequence is a
2406      //   derived-to-base Conversion (13.3.3.1).
2407      ICS->ConversionKind = ImplicitConversionSequence::StandardConversion;
2408      ICS->Standard.First = ICK_Identity;
2409      ICS->Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity;
2410      ICS->Standard.Third = ICK_Identity;
2411      ICS->Standard.FromTypePtr = T2.getAsOpaquePtr();
2412      ICS->Standard.ToTypePtr = T1.getAsOpaquePtr();
2413      ICS->Standard.ReferenceBinding = true;
2414      ICS->Standard.DirectBinding = true;
2415      ICS->Standard.RRefBinding = false;
2416      ICS->Standard.CopyConstructor = 0;
2417
2418      // Nothing more to do: the inaccessibility/ambiguity check for
2419      // derived-to-base conversions is suppressed when we're
2420      // computing the implicit conversion sequence (C++
2421      // [over.best.ics]p2).
2422      return false;
2423    } else {
2424      // Perform the conversion.
2425      // FIXME: Binding to a subobject of the lvalue is going to require more
2426      // AST annotation than this.
2427      ImpCastExprToType(Init, T1, /*isLvalue=*/true);
2428    }
2429  }
2430
2431  //       -- has a class type (i.e., T2 is a class type) and can be
2432  //          implicitly converted to an lvalue of type “cv3 T3,”
2433  //          where “cv1 T1” is reference-compatible with “cv3 T3”
2434  //          92) (this conversion is selected by enumerating the
2435  //          applicable conversion functions (13.3.1.6) and choosing
2436  //          the best one through overload resolution (13.3)),
2437  if (!isRValRef && !SuppressUserConversions && T2->isRecordType()) {
2438    // FIXME: Look for conversions in base classes!
2439    CXXRecordDecl *T2RecordDecl
2440      = dyn_cast<CXXRecordDecl>(T2->getAsRecordType()->getDecl());
2441
2442    OverloadCandidateSet CandidateSet;
2443    OverloadedFunctionDecl *Conversions
2444      = T2RecordDecl->getConversionFunctions();
2445    for (OverloadedFunctionDecl::function_iterator Func
2446           = Conversions->function_begin();
2447         Func != Conversions->function_end(); ++Func) {
2448      CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func);
2449
2450      // If the conversion function doesn't return a reference type,
2451      // it can't be considered for this conversion.
2452      if (Conv->getConversionType()->isLValueReferenceType() &&
2453          (AllowExplicit || !Conv->isExplicit()))
2454        AddConversionCandidate(Conv, Init, DeclType, CandidateSet);
2455    }
2456
2457    OverloadCandidateSet::iterator Best;
2458    switch (BestViableFunction(CandidateSet, Init->getLocStart(), Best)) {
2459    case OR_Success:
2460      // This is a direct binding.
2461      BindsDirectly = true;
2462
2463      if (ICS) {
2464        // C++ [over.ics.ref]p1:
2465        //
2466        //   [...] If the parameter binds directly to the result of
2467        //   applying a conversion function to the argument
2468        //   expression, the implicit conversion sequence is a
2469        //   user-defined conversion sequence (13.3.3.1.2), with the
2470        //   second standard conversion sequence either an identity
2471        //   conversion or, if the conversion function returns an
2472        //   entity of a type that is a derived class of the parameter
2473        //   type, a derived-to-base Conversion.
2474        ICS->ConversionKind = ImplicitConversionSequence::UserDefinedConversion;
2475        ICS->UserDefined.Before = Best->Conversions[0].Standard;
2476        ICS->UserDefined.After = Best->FinalConversion;
2477        ICS->UserDefined.ConversionFunction = Best->Function;
2478        assert(ICS->UserDefined.After.ReferenceBinding &&
2479               ICS->UserDefined.After.DirectBinding &&
2480               "Expected a direct reference binding!");
2481        return false;
2482      } else {
2483        // Perform the conversion.
2484        // FIXME: Binding to a subobject of the lvalue is going to require more
2485        // AST annotation than this.
2486        ImpCastExprToType(Init, T1, /*isLvalue=*/true);
2487      }
2488      break;
2489
2490    case OR_Ambiguous:
2491      assert(false && "Ambiguous reference binding conversions not implemented.");
2492      return true;
2493
2494    case OR_No_Viable_Function:
2495    case OR_Deleted:
2496      // There was no suitable conversion, or we found a deleted
2497      // conversion; continue with other checks.
2498      break;
2499    }
2500  }
2501
2502  if (BindsDirectly) {
2503    // C++ [dcl.init.ref]p4:
2504    //   [...] In all cases where the reference-related or
2505    //   reference-compatible relationship of two types is used to
2506    //   establish the validity of a reference binding, and T1 is a
2507    //   base class of T2, a program that necessitates such a binding
2508    //   is ill-formed if T1 is an inaccessible (clause 11) or
2509    //   ambiguous (10.2) base class of T2.
2510    //
2511    // Note that we only check this condition when we're allowed to
2512    // complain about errors, because we should not be checking for
2513    // ambiguity (or inaccessibility) unless the reference binding
2514    // actually happens.
2515    if (DerivedToBase)
2516      return CheckDerivedToBaseConversion(T2, T1,
2517                                          Init->getSourceRange().getBegin(),
2518                                          Init->getSourceRange());
2519    else
2520      return false;
2521  }
2522
2523  //     -- Otherwise, the reference shall be to a non-volatile const
2524  //        type (i.e., cv1 shall be const), or the reference shall be an
2525  //        rvalue reference and the initializer expression shall be an rvalue.
2526  if (!isRValRef && T1.getCVRQualifiers() != QualType::Const) {
2527    if (!ICS)
2528      Diag(Init->getSourceRange().getBegin(),
2529           diag::err_not_reference_to_const_init)
2530        << T1 << (InitLvalue != Expr::LV_Valid? "temporary" : "value")
2531        << T2 << Init->getSourceRange();
2532    return true;
2533  }
2534
2535  //       -- If the initializer expression is an rvalue, with T2 a
2536  //          class type, and “cv1 T1” is reference-compatible with
2537  //          “cv2 T2,” the reference is bound in one of the
2538  //          following ways (the choice is implementation-defined):
2539  //
2540  //          -- The reference is bound to the object represented by
2541  //             the rvalue (see 3.10) or to a sub-object within that
2542  //             object.
2543  //
2544  //          -- A temporary of type “cv1 T2” [sic] is created, and
2545  //             a constructor is called to copy the entire rvalue
2546  //             object into the temporary. The reference is bound to
2547  //             the temporary or to a sub-object within the
2548  //             temporary.
2549  //
2550  //          The constructor that would be used to make the copy
2551  //          shall be callable whether or not the copy is actually
2552  //          done.
2553  //
2554  // Note that C++0x [dcl.init.ref]p5 takes away this implementation
2555  // freedom, so we will always take the first option and never build
2556  // a temporary in this case. FIXME: We will, however, have to check
2557  // for the presence of a copy constructor in C++98/03 mode.
2558  if (InitLvalue != Expr::LV_Valid && T2->isRecordType() &&
2559      RefRelationship >= Ref_Compatible_With_Added_Qualification) {
2560    if (ICS) {
2561      ICS->ConversionKind = ImplicitConversionSequence::StandardConversion;
2562      ICS->Standard.First = ICK_Identity;
2563      ICS->Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity;
2564      ICS->Standard.Third = ICK_Identity;
2565      ICS->Standard.FromTypePtr = T2.getAsOpaquePtr();
2566      ICS->Standard.ToTypePtr = T1.getAsOpaquePtr();
2567      ICS->Standard.ReferenceBinding = true;
2568      ICS->Standard.DirectBinding = false;
2569      ICS->Standard.RRefBinding = isRValRef;
2570      ICS->Standard.CopyConstructor = 0;
2571    } else {
2572      // FIXME: Binding to a subobject of the rvalue is going to require more
2573      // AST annotation than this.
2574      ImpCastExprToType(Init, T1, /*isLvalue=*/false);
2575    }
2576    return false;
2577  }
2578
2579  //       -- Otherwise, a temporary of type “cv1 T1” is created and
2580  //          initialized from the initializer expression using the
2581  //          rules for a non-reference copy initialization (8.5). The
2582  //          reference is then bound to the temporary. If T1 is
2583  //          reference-related to T2, cv1 must be the same
2584  //          cv-qualification as, or greater cv-qualification than,
2585  //          cv2; otherwise, the program is ill-formed.
2586  if (RefRelationship == Ref_Related) {
2587    // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
2588    // we would be reference-compatible or reference-compatible with
2589    // added qualification. But that wasn't the case, so the reference
2590    // initialization fails.
2591    if (!ICS)
2592      Diag(Init->getSourceRange().getBegin(),
2593           diag::err_reference_init_drops_quals)
2594        << T1 << (InitLvalue != Expr::LV_Valid? "temporary" : "value")
2595        << T2 << Init->getSourceRange();
2596    return true;
2597  }
2598
2599  // If at least one of the types is a class type, the types are not
2600  // related, and we aren't allowed any user conversions, the
2601  // reference binding fails. This case is important for breaking
2602  // recursion, since TryImplicitConversion below will attempt to
2603  // create a temporary through the use of a copy constructor.
2604  if (SuppressUserConversions && RefRelationship == Ref_Incompatible &&
2605      (T1->isRecordType() || T2->isRecordType())) {
2606    if (!ICS)
2607      Diag(Init->getSourceRange().getBegin(),
2608           diag::err_typecheck_convert_incompatible)
2609        << DeclType << Init->getType() << "initializing" << Init->getSourceRange();
2610    return true;
2611  }
2612
2613  // Actually try to convert the initializer to T1.
2614  if (ICS) {
2615    // C++ [over.ics.ref]p2:
2616    //
2617    //   When a parameter of reference type is not bound directly to
2618    //   an argument expression, the conversion sequence is the one
2619    //   required to convert the argument expression to the
2620    //   underlying type of the reference according to
2621    //   13.3.3.1. Conceptually, this conversion sequence corresponds
2622    //   to copy-initializing a temporary of the underlying type with
2623    //   the argument expression. Any difference in top-level
2624    //   cv-qualification is subsumed by the initialization itself
2625    //   and does not constitute a conversion.
2626    *ICS = TryImplicitConversion(Init, T1, SuppressUserConversions);
2627    // Of course, that's still a reference binding.
2628    if (ICS->ConversionKind == ImplicitConversionSequence::StandardConversion) {
2629      ICS->Standard.ReferenceBinding = true;
2630      ICS->Standard.RRefBinding = isRValRef;
2631    } else if(ICS->ConversionKind ==
2632              ImplicitConversionSequence::UserDefinedConversion) {
2633      ICS->UserDefined.After.ReferenceBinding = true;
2634      ICS->UserDefined.After.RRefBinding = isRValRef;
2635    }
2636    return ICS->ConversionKind == ImplicitConversionSequence::BadConversion;
2637  } else {
2638    return PerformImplicitConversion(Init, T1, "initializing");
2639  }
2640}
2641
2642/// CheckOverloadedOperatorDeclaration - Check whether the declaration
2643/// of this overloaded operator is well-formed. If so, returns false;
2644/// otherwise, emits appropriate diagnostics and returns true.
2645bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) {
2646  assert(FnDecl && FnDecl->isOverloadedOperator() &&
2647         "Expected an overloaded operator declaration");
2648
2649  OverloadedOperatorKind Op = FnDecl->getOverloadedOperator();
2650
2651  // C++ [over.oper]p5:
2652  //   The allocation and deallocation functions, operator new,
2653  //   operator new[], operator delete and operator delete[], are
2654  //   described completely in 3.7.3. The attributes and restrictions
2655  //   found in the rest of this subclause do not apply to them unless
2656  //   explicitly stated in 3.7.3.
2657  // FIXME: Write a separate routine for checking this. For now, just allow it.
2658  if (Op == OO_New || Op == OO_Array_New ||
2659      Op == OO_Delete || Op == OO_Array_Delete)
2660    return false;
2661
2662  // C++ [over.oper]p6:
2663  //   An operator function shall either be a non-static member
2664  //   function or be a non-member function and have at least one
2665  //   parameter whose type is a class, a reference to a class, an
2666  //   enumeration, or a reference to an enumeration.
2667  if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) {
2668    if (MethodDecl->isStatic())
2669      return Diag(FnDecl->getLocation(),
2670                  diag::err_operator_overload_static) << FnDecl->getDeclName();
2671  } else {
2672    bool ClassOrEnumParam = false;
2673    for (FunctionDecl::param_iterator Param = FnDecl->param_begin(),
2674                                   ParamEnd = FnDecl->param_end();
2675         Param != ParamEnd; ++Param) {
2676      QualType ParamType = (*Param)->getType().getNonReferenceType();
2677      if (ParamType->isRecordType() || ParamType->isEnumeralType()) {
2678        ClassOrEnumParam = true;
2679        break;
2680      }
2681    }
2682
2683    if (!ClassOrEnumParam)
2684      return Diag(FnDecl->getLocation(),
2685                  diag::err_operator_overload_needs_class_or_enum)
2686        << FnDecl->getDeclName();
2687  }
2688
2689  // C++ [over.oper]p8:
2690  //   An operator function cannot have default arguments (8.3.6),
2691  //   except where explicitly stated below.
2692  //
2693  // Only the function-call operator allows default arguments
2694  // (C++ [over.call]p1).
2695  if (Op != OO_Call) {
2696    for (FunctionDecl::param_iterator Param = FnDecl->param_begin();
2697         Param != FnDecl->param_end(); ++Param) {
2698      if ((*Param)->hasUnparsedDefaultArg())
2699        return Diag((*Param)->getLocation(),
2700                    diag::err_operator_overload_default_arg)
2701          << FnDecl->getDeclName();
2702      else if (Expr *DefArg = (*Param)->getDefaultArg())
2703        return Diag((*Param)->getLocation(),
2704                    diag::err_operator_overload_default_arg)
2705          << FnDecl->getDeclName() << DefArg->getSourceRange();
2706    }
2707  }
2708
2709  static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = {
2710    { false, false, false }
2711#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
2712    , { Unary, Binary, MemberOnly }
2713#include "clang/Basic/OperatorKinds.def"
2714  };
2715
2716  bool CanBeUnaryOperator = OperatorUses[Op][0];
2717  bool CanBeBinaryOperator = OperatorUses[Op][1];
2718  bool MustBeMemberOperator = OperatorUses[Op][2];
2719
2720  // C++ [over.oper]p8:
2721  //   [...] Operator functions cannot have more or fewer parameters
2722  //   than the number required for the corresponding operator, as
2723  //   described in the rest of this subclause.
2724  unsigned NumParams = FnDecl->getNumParams()
2725                     + (isa<CXXMethodDecl>(FnDecl)? 1 : 0);
2726  if (Op != OO_Call &&
2727      ((NumParams == 1 && !CanBeUnaryOperator) ||
2728       (NumParams == 2 && !CanBeBinaryOperator) ||
2729       (NumParams < 1) || (NumParams > 2))) {
2730    // We have the wrong number of parameters.
2731    unsigned ErrorKind;
2732    if (CanBeUnaryOperator && CanBeBinaryOperator) {
2733      ErrorKind = 2;  // 2 -> unary or binary.
2734    } else if (CanBeUnaryOperator) {
2735      ErrorKind = 0;  // 0 -> unary
2736    } else {
2737      assert(CanBeBinaryOperator &&
2738             "All non-call overloaded operators are unary or binary!");
2739      ErrorKind = 1;  // 1 -> binary
2740    }
2741
2742    return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be)
2743      << FnDecl->getDeclName() << NumParams << ErrorKind;
2744  }
2745
2746  // Overloaded operators other than operator() cannot be variadic.
2747  if (Op != OO_Call &&
2748      FnDecl->getType()->getAsFunctionProtoType()->isVariadic()) {
2749    return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic)
2750      << FnDecl->getDeclName();
2751  }
2752
2753  // Some operators must be non-static member functions.
2754  if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) {
2755    return Diag(FnDecl->getLocation(),
2756                diag::err_operator_overload_must_be_member)
2757      << FnDecl->getDeclName();
2758  }
2759
2760  // C++ [over.inc]p1:
2761  //   The user-defined function called operator++ implements the
2762  //   prefix and postfix ++ operator. If this function is a member
2763  //   function with no parameters, or a non-member function with one
2764  //   parameter of class or enumeration type, it defines the prefix
2765  //   increment operator ++ for objects of that type. If the function
2766  //   is a member function with one parameter (which shall be of type
2767  //   int) or a non-member function with two parameters (the second
2768  //   of which shall be of type int), it defines the postfix
2769  //   increment operator ++ for objects of that type.
2770  if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) {
2771    ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1);
2772    bool ParamIsInt = false;
2773    if (const BuiltinType *BT = LastParam->getType()->getAsBuiltinType())
2774      ParamIsInt = BT->getKind() == BuiltinType::Int;
2775
2776    if (!ParamIsInt)
2777      return Diag(LastParam->getLocation(),
2778                  diag::err_operator_overload_post_incdec_must_be_int)
2779        << LastParam->getType() << (Op == OO_MinusMinus);
2780  }
2781
2782  // Notify the class if it got an assignment operator.
2783  if (Op == OO_Equal) {
2784    // Would have returned earlier otherwise.
2785    assert(isa<CXXMethodDecl>(FnDecl) &&
2786      "Overloaded = not member, but not filtered.");
2787    CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
2788    Method->getParent()->addedAssignmentOperator(Context, Method);
2789  }
2790
2791  return false;
2792}
2793
2794/// ActOnStartLinkageSpecification - Parsed the beginning of a C++
2795/// linkage specification, including the language and (if present)
2796/// the '{'. ExternLoc is the location of the 'extern', LangLoc is
2797/// the location of the language string literal, which is provided
2798/// by Lang/StrSize. LBraceLoc, if valid, provides the location of
2799/// the '{' brace. Otherwise, this linkage specification does not
2800/// have any braces.
2801Sema::DeclPtrTy Sema::ActOnStartLinkageSpecification(Scope *S,
2802                                                     SourceLocation ExternLoc,
2803                                                     SourceLocation LangLoc,
2804                                                     const char *Lang,
2805                                                     unsigned StrSize,
2806                                                     SourceLocation LBraceLoc) {
2807  LinkageSpecDecl::LanguageIDs Language;
2808  if (strncmp(Lang, "\"C\"", StrSize) == 0)
2809    Language = LinkageSpecDecl::lang_c;
2810  else if (strncmp(Lang, "\"C++\"", StrSize) == 0)
2811    Language = LinkageSpecDecl::lang_cxx;
2812  else {
2813    Diag(LangLoc, diag::err_bad_language);
2814    return DeclPtrTy();
2815  }
2816
2817  // FIXME: Add all the various semantics of linkage specifications
2818
2819  LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext,
2820                                               LangLoc, Language,
2821                                               LBraceLoc.isValid());
2822  CurContext->addDecl(Context, D);
2823  PushDeclContext(S, D);
2824  return DeclPtrTy::make(D);
2825}
2826
2827/// ActOnFinishLinkageSpecification - Completely the definition of
2828/// the C++ linkage specification LinkageSpec. If RBraceLoc is
2829/// valid, it's the position of the closing '}' brace in a linkage
2830/// specification that uses braces.
2831Sema::DeclPtrTy Sema::ActOnFinishLinkageSpecification(Scope *S,
2832                                                      DeclPtrTy LinkageSpec,
2833                                                      SourceLocation RBraceLoc) {
2834  if (LinkageSpec)
2835    PopDeclContext();
2836  return LinkageSpec;
2837}
2838
2839/// \brief Perform semantic analysis for the variable declaration that
2840/// occurs within a C++ catch clause, returning the newly-created
2841/// variable.
2842VarDecl *Sema::BuildExceptionDeclaration(Scope *S, QualType ExDeclType,
2843                                         IdentifierInfo *Name,
2844                                         SourceLocation Loc,
2845                                         SourceRange Range) {
2846  bool Invalid = false;
2847
2848  // Arrays and functions decay.
2849  if (ExDeclType->isArrayType())
2850    ExDeclType = Context.getArrayDecayedType(ExDeclType);
2851  else if (ExDeclType->isFunctionType())
2852    ExDeclType = Context.getPointerType(ExDeclType);
2853
2854  // C++ 15.3p1: The exception-declaration shall not denote an incomplete type.
2855  // The exception-declaration shall not denote a pointer or reference to an
2856  // incomplete type, other than [cv] void*.
2857  // N2844 forbids rvalue references.
2858  if(!ExDeclType->isDependentType() && ExDeclType->isRValueReferenceType()) {
2859    Diag(Loc, diag::err_catch_rvalue_ref) << Range;
2860    Invalid = true;
2861  }
2862
2863  QualType BaseType = ExDeclType;
2864  int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference
2865  unsigned DK = diag::err_catch_incomplete;
2866  if (const PointerType *Ptr = BaseType->getAsPointerType()) {
2867    BaseType = Ptr->getPointeeType();
2868    Mode = 1;
2869    DK = diag::err_catch_incomplete_ptr;
2870  } else if(const ReferenceType *Ref = BaseType->getAsReferenceType()) {
2871    // For the purpose of error recovery, we treat rvalue refs like lvalue refs.
2872    BaseType = Ref->getPointeeType();
2873    Mode = 2;
2874    DK = diag::err_catch_incomplete_ref;
2875  }
2876  if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) &&
2877      !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK))
2878    Invalid = true;
2879
2880  if (!Invalid && !ExDeclType->isDependentType() &&
2881      RequireNonAbstractType(Loc, ExDeclType,
2882                             diag::err_abstract_type_in_decl,
2883                             AbstractVariableType))
2884    Invalid = true;
2885
2886  // FIXME: Need to test for ability to copy-construct and destroy the
2887  // exception variable.
2888
2889  // FIXME: Need to check for abstract classes.
2890
2891  VarDecl *ExDecl = VarDecl::Create(Context, CurContext, Loc,
2892                                    Name, ExDeclType, VarDecl::None,
2893                                    Range.getBegin());
2894
2895  if (Invalid)
2896    ExDecl->setInvalidDecl();
2897
2898  return ExDecl;
2899}
2900
2901/// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch
2902/// handler.
2903Sema::DeclPtrTy Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D) {
2904  QualType ExDeclType = GetTypeForDeclarator(D, S);
2905
2906  bool Invalid = D.isInvalidType();
2907  IdentifierInfo *II = D.getIdentifier();
2908  if (NamedDecl *PrevDecl = LookupName(S, II, LookupOrdinaryName)) {
2909    // The scope should be freshly made just for us. There is just no way
2910    // it contains any previous declaration.
2911    assert(!S->isDeclScope(DeclPtrTy::make(PrevDecl)));
2912    if (PrevDecl->isTemplateParameter()) {
2913      // Maybe we will complain about the shadowed template parameter.
2914      DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
2915    }
2916  }
2917
2918  if (D.getCXXScopeSpec().isSet() && !Invalid) {
2919    Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator)
2920      << D.getCXXScopeSpec().getRange();
2921    Invalid = true;
2922  }
2923
2924  VarDecl *ExDecl = BuildExceptionDeclaration(S, ExDeclType,
2925                                              D.getIdentifier(),
2926                                              D.getIdentifierLoc(),
2927                                            D.getDeclSpec().getSourceRange());
2928
2929  if (Invalid)
2930    ExDecl->setInvalidDecl();
2931
2932  // Add the exception declaration into this scope.
2933  if (II)
2934    PushOnScopeChains(ExDecl, S);
2935  else
2936    CurContext->addDecl(Context, ExDecl);
2937
2938  ProcessDeclAttributes(S, ExDecl, D);
2939  return DeclPtrTy::make(ExDecl);
2940}
2941
2942Sema::DeclPtrTy Sema::ActOnStaticAssertDeclaration(SourceLocation AssertLoc,
2943                                                   ExprArg assertexpr,
2944                                                   ExprArg assertmessageexpr) {
2945  Expr *AssertExpr = (Expr *)assertexpr.get();
2946  StringLiteral *AssertMessage =
2947    cast<StringLiteral>((Expr *)assertmessageexpr.get());
2948
2949  if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent()) {
2950    llvm::APSInt Value(32);
2951    if (!AssertExpr->isIntegerConstantExpr(Value, Context)) {
2952      Diag(AssertLoc, diag::err_static_assert_expression_is_not_constant) <<
2953        AssertExpr->getSourceRange();
2954      return DeclPtrTy();
2955    }
2956
2957    if (Value == 0) {
2958      std::string str(AssertMessage->getStrData(),
2959                      AssertMessage->getByteLength());
2960      Diag(AssertLoc, diag::err_static_assert_failed)
2961        << str << AssertExpr->getSourceRange();
2962    }
2963  }
2964
2965  assertexpr.release();
2966  assertmessageexpr.release();
2967  Decl *Decl = StaticAssertDecl::Create(Context, CurContext, AssertLoc,
2968                                        AssertExpr, AssertMessage);
2969
2970  CurContext->addDecl(Context, Decl);
2971  return DeclPtrTy::make(Decl);
2972}
2973
2974bool Sema::ActOnFriendDecl(Scope *S, SourceLocation FriendLoc, DeclPtrTy Dcl) {
2975  if (!(S->getFlags() & Scope::ClassScope)) {
2976    Diag(FriendLoc, diag::err_friend_decl_outside_class);
2977    return true;
2978  }
2979
2980  return false;
2981}
2982
2983void Sema::SetDeclDeleted(DeclPtrTy dcl, SourceLocation DelLoc) {
2984  Decl *Dcl = dcl.getAs<Decl>();
2985  FunctionDecl *Fn = dyn_cast<FunctionDecl>(Dcl);
2986  if (!Fn) {
2987    Diag(DelLoc, diag::err_deleted_non_function);
2988    return;
2989  }
2990  if (const FunctionDecl *Prev = Fn->getPreviousDeclaration()) {
2991    Diag(DelLoc, diag::err_deleted_decl_not_first);
2992    Diag(Prev->getLocation(), diag::note_previous_declaration);
2993    // If the declaration wasn't the first, we delete the function anyway for
2994    // recovery.
2995  }
2996  Fn->setDeleted();
2997}
2998
2999static void SearchForReturnInStmt(Sema &Self, Stmt *S) {
3000  for (Stmt::child_iterator CI = S->child_begin(), E = S->child_end(); CI != E;
3001       ++CI) {
3002    Stmt *SubStmt = *CI;
3003    if (!SubStmt)
3004      continue;
3005    if (isa<ReturnStmt>(SubStmt))
3006      Self.Diag(SubStmt->getSourceRange().getBegin(),
3007           diag::err_return_in_constructor_handler);
3008    if (!isa<Expr>(SubStmt))
3009      SearchForReturnInStmt(Self, SubStmt);
3010  }
3011}
3012
3013void Sema::DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock) {
3014  for (unsigned I = 0, E = TryBlock->getNumHandlers(); I != E; ++I) {
3015    CXXCatchStmt *Handler = TryBlock->getHandler(I);
3016    SearchForReturnInStmt(*this, Handler);
3017  }
3018}
3019
3020bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
3021                                             const CXXMethodDecl *Old) {
3022  QualType NewTy = New->getType()->getAsFunctionType()->getResultType();
3023  QualType OldTy = Old->getType()->getAsFunctionType()->getResultType();
3024
3025  QualType CNewTy = Context.getCanonicalType(NewTy);
3026  QualType COldTy = Context.getCanonicalType(OldTy);
3027
3028  if (CNewTy == COldTy &&
3029      CNewTy.getCVRQualifiers() == COldTy.getCVRQualifiers())
3030    return false;
3031
3032  // Check if the return types are covariant
3033  QualType NewClassTy, OldClassTy;
3034
3035  /// Both types must be pointers or references to classes.
3036  if (PointerType *NewPT = dyn_cast<PointerType>(NewTy)) {
3037    if (PointerType *OldPT = dyn_cast<PointerType>(OldTy)) {
3038      NewClassTy = NewPT->getPointeeType();
3039      OldClassTy = OldPT->getPointeeType();
3040    }
3041  } else if (ReferenceType *NewRT = dyn_cast<ReferenceType>(NewTy)) {
3042    if (ReferenceType *OldRT = dyn_cast<ReferenceType>(OldTy)) {
3043      NewClassTy = NewRT->getPointeeType();
3044      OldClassTy = OldRT->getPointeeType();
3045    }
3046  }
3047
3048  // The return types aren't either both pointers or references to a class type.
3049  if (NewClassTy.isNull()) {
3050    Diag(New->getLocation(),
3051         diag::err_different_return_type_for_overriding_virtual_function)
3052      << New->getDeclName() << NewTy << OldTy;
3053    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
3054
3055    return true;
3056  }
3057
3058  if (NewClassTy.getUnqualifiedType() != OldClassTy.getUnqualifiedType()) {
3059    // Check if the new class derives from the old class.
3060    if (!IsDerivedFrom(NewClassTy, OldClassTy)) {
3061      Diag(New->getLocation(),
3062           diag::err_covariant_return_not_derived)
3063      << New->getDeclName() << NewTy << OldTy;
3064      Diag(Old->getLocation(), diag::note_overridden_virtual_function);
3065      return true;
3066    }
3067
3068    // Check if we the conversion from derived to base is valid.
3069    if (CheckDerivedToBaseConversion(NewClassTy, OldClassTy,
3070                      diag::err_covariant_return_inaccessible_base,
3071                      diag::err_covariant_return_ambiguous_derived_to_base_conv,
3072                      // FIXME: Should this point to the return type?
3073                      New->getLocation(), SourceRange(), New->getDeclName())) {
3074      Diag(Old->getLocation(), diag::note_overridden_virtual_function);
3075      return true;
3076    }
3077  }
3078
3079  // The qualifiers of the return types must be the same.
3080  if (CNewTy.getCVRQualifiers() != COldTy.getCVRQualifiers()) {
3081    Diag(New->getLocation(),
3082         diag::err_covariant_return_type_different_qualifications)
3083    << New->getDeclName() << NewTy << OldTy;
3084    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
3085    return true;
3086  };
3087
3088
3089  // The new class type must have the same or less qualifiers as the old type.
3090  if (NewClassTy.isMoreQualifiedThan(OldClassTy)) {
3091    Diag(New->getLocation(),
3092         diag::err_covariant_return_type_class_type_more_qualified)
3093    << New->getDeclName() << NewTy << OldTy;
3094    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
3095    return true;
3096  };
3097
3098  return false;
3099}
3100
3101/// ActOnCXXEnterDeclInitializer - Invoked when we are about to parse an
3102/// initializer for the declaration 'Dcl'.
3103/// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
3104/// static data member of class X, names should be looked up in the scope of
3105/// class X.
3106void Sema::ActOnCXXEnterDeclInitializer(Scope *S, DeclPtrTy Dcl) {
3107  Decl *D = Dcl.getAs<Decl>();
3108  // If there is no declaration, there was an error parsing it.
3109  if (D == 0)
3110    return;
3111
3112  // Check whether it is a declaration with a nested name specifier like
3113  // int foo::bar;
3114  if (!D->isOutOfLine())
3115    return;
3116
3117  // C++ [basic.lookup.unqual]p13
3118  //
3119  // A name used in the definition of a static data member of class X
3120  // (after the qualified-id of the static member) is looked up as if the name
3121  // was used in a member function of X.
3122
3123  // Change current context into the context of the initializing declaration.
3124  EnterDeclaratorContext(S, D->getDeclContext());
3125}
3126
3127/// ActOnCXXExitDeclInitializer - Invoked after we are finished parsing an
3128/// initializer for the declaration 'Dcl'.
3129void Sema::ActOnCXXExitDeclInitializer(Scope *S, DeclPtrTy Dcl) {
3130  Decl *D = Dcl.getAs<Decl>();
3131  // If there is no declaration, there was an error parsing it.
3132  if (D == 0)
3133    return;
3134
3135  // Check whether it is a declaration with a nested name specifier like
3136  // int foo::bar;
3137  if (!D->isOutOfLine())
3138    return;
3139
3140  assert(S->getEntity() == D->getDeclContext() && "Context imbalance!");
3141  ExitDeclaratorContext(S);
3142}
3143