SemaDecl.cpp revision 7da97d0f31e1ec16998d3de2cfd2e88fe3736673
1//===--- SemaDecl.cpp - Semantic Analysis for 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 declarations.
11//
12//===----------------------------------------------------------------------===//
13
14#include "Sema.h"
15#include "clang/AST/APValue.h"
16#include "clang/AST/ASTConsumer.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/DeclObjC.h"
19#include "clang/AST/DeclTemplate.h"
20#include "clang/AST/ExprCXX.h"
21#include "clang/AST/StmtCXX.h"
22#include "clang/Parse/DeclSpec.h"
23#include "clang/Basic/TargetInfo.h"
24#include "clang/Basic/SourceManager.h"
25// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's)
26#include "clang/Lex/Preprocessor.h"
27#include "clang/Lex/HeaderSearch.h"
28#include "llvm/ADT/SmallSet.h"
29#include "llvm/ADT/STLExtras.h"
30#include <algorithm>
31#include <functional>
32using namespace clang;
33
34/// getDeclName - Return a pretty name for the specified decl if possible, or
35/// an empty string if not.  This is used for pretty crash reporting.
36std::string Sema::getDeclName(DeclPtrTy d) {
37  Decl *D = d.getAs<Decl>();
38  if (NamedDecl *DN = dyn_cast_or_null<NamedDecl>(D))
39    return DN->getQualifiedNameAsString();
40  return "";
41}
42
43Sema::DeclGroupPtrTy Sema::ConvertDeclToDeclGroup(DeclPtrTy Ptr) {
44  return DeclGroupPtrTy::make(DeclGroupRef(Ptr.getAs<Decl>()));
45}
46
47/// \brief If the identifier refers to a type name within this scope,
48/// return the declaration of that type.
49///
50/// This routine performs ordinary name lookup of the identifier II
51/// within the given scope, with optional C++ scope specifier SS, to
52/// determine whether the name refers to a type. If so, returns an
53/// opaque pointer (actually a QualType) corresponding to that
54/// type. Otherwise, returns NULL.
55///
56/// If name lookup results in an ambiguity, this routine will complain
57/// and then return NULL.
58Sema::TypeTy *Sema::getTypeName(IdentifierInfo &II, SourceLocation NameLoc,
59                                Scope *S, const CXXScopeSpec *SS) {
60  // C++ [temp.res]p3:
61  //   A qualified-id that refers to a type and in which the
62  //   nested-name-specifier depends on a template-parameter (14.6.2)
63  //   shall be prefixed by the keyword typename to indicate that the
64  //   qualified-id denotes a type, forming an
65  //   elaborated-type-specifier (7.1.5.3).
66  //
67  // We therefore do not perform any name lookup up SS is a dependent
68  // scope name. FIXME: we will need to perform a special kind of
69  // lookup if the scope specifier names a member of the current
70  // instantiation.
71  if (SS && isDependentScopeSpecifier(*SS))
72    return 0;
73
74  NamedDecl *IIDecl = 0;
75  LookupResult Result = LookupParsedName(S, SS, &II, LookupOrdinaryName,
76                                         false, false);
77  switch (Result.getKind()) {
78  case LookupResult::NotFound:
79  case LookupResult::FoundOverloaded:
80    return 0;
81
82  case LookupResult::AmbiguousBaseSubobjectTypes:
83  case LookupResult::AmbiguousBaseSubobjects:
84  case LookupResult::AmbiguousReference: {
85    // Look to see if we have a type anywhere in the list of results.
86    for (LookupResult::iterator Res = Result.begin(), ResEnd = Result.end();
87         Res != ResEnd; ++Res) {
88      if (isa<TypeDecl>(*Res) || isa<ObjCInterfaceDecl>(*Res)) {
89        if (!IIDecl ||
90            (*Res)->getLocation().getRawEncoding() <
91              IIDecl->getLocation().getRawEncoding())
92          IIDecl = *Res;
93      }
94    }
95
96    if (!IIDecl) {
97      // None of the entities we found is a type, so there is no way
98      // to even assume that the result is a type. In this case, don't
99      // complain about the ambiguity. The parser will either try to
100      // perform this lookup again (e.g., as an object name), which
101      // will produce the ambiguity, or will complain that it expected
102      // a type name.
103      Result.Destroy();
104      return 0;
105    }
106
107    // We found a type within the ambiguous lookup; diagnose the
108    // ambiguity and then return that type. This might be the right
109    // answer, or it might not be, but it suppresses any attempt to
110    // perform the name lookup again.
111    DiagnoseAmbiguousLookup(Result, DeclarationName(&II), NameLoc);
112    break;
113  }
114
115  case LookupResult::Found:
116    IIDecl = Result.getAsDecl();
117    break;
118  }
119
120  if (IIDecl) {
121    QualType T;
122
123    if (TypeDecl *TD = dyn_cast<TypeDecl>(IIDecl)) {
124      // Check whether we can use this type
125      (void)DiagnoseUseOfDecl(IIDecl, NameLoc);
126
127      if (getLangOptions().CPlusPlus) {
128        // C++ [temp.local]p2:
129        //   Within the scope of a class template specialization or
130        //   partial specialization, when the injected-class-name is
131        //   not followed by a <, it is equivalent to the
132        //   injected-class-name followed by the template-argument s
133        //   of the class template specialization or partial
134        //   specialization enclosed in <>.
135        if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD))
136          if (RD->isInjectedClassName())
137            if (ClassTemplateDecl *Template = RD->getDescribedClassTemplate())
138              T = Template->getInjectedClassNameType(Context);
139      }
140
141      if (T.isNull())
142        T = Context.getTypeDeclType(TD);
143    } else if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(IIDecl)) {
144      // Check whether we can use this interface.
145      (void)DiagnoseUseOfDecl(IIDecl, NameLoc);
146
147      T = Context.getObjCInterfaceType(IDecl);
148    } else
149      return 0;
150
151    if (SS)
152      T = getQualifiedNameType(*SS, T);
153
154    return T.getAsOpaquePtr();
155  }
156
157  return 0;
158}
159
160/// isTagName() - This method is called *for error recovery purposes only*
161/// to determine if the specified name is a valid tag name ("struct foo").  If
162/// so, this returns the TST for the tag corresponding to it (TST_enum,
163/// TST_union, TST_struct, TST_class).  This is used to diagnose cases in C
164/// where the user forgot to specify the tag.
165DeclSpec::TST Sema::isTagName(IdentifierInfo &II, Scope *S) {
166  // Do a tag name lookup in this scope.
167  LookupResult R = LookupName(S, &II, LookupTagName, false, false);
168  if (R.getKind() == LookupResult::Found)
169    if (const TagDecl *TD = dyn_cast<TagDecl>(R.getAsDecl())) {
170      switch (TD->getTagKind()) {
171      case TagDecl::TK_struct: return DeclSpec::TST_struct;
172      case TagDecl::TK_union:  return DeclSpec::TST_union;
173      case TagDecl::TK_class:  return DeclSpec::TST_class;
174      case TagDecl::TK_enum:   return DeclSpec::TST_enum;
175      }
176    }
177
178  return DeclSpec::TST_unspecified;
179}
180
181
182
183DeclContext *Sema::getContainingDC(DeclContext *DC) {
184  if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) {
185    // A C++ out-of-line method will return to the file declaration context.
186    if (MD->isOutOfLineDefinition())
187      return MD->getLexicalDeclContext();
188
189    // A C++ inline method is parsed *after* the topmost class it was declared
190    // in is fully parsed (it's "complete").
191    // The parsing of a C++ inline method happens at the declaration context of
192    // the topmost (non-nested) class it is lexically declared in.
193    assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record.");
194    DC = MD->getParent();
195    while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent()))
196      DC = RD;
197
198    // Return the declaration context of the topmost class the inline method is
199    // declared in.
200    return DC;
201  }
202
203  if (isa<ObjCMethodDecl>(DC))
204    return Context.getTranslationUnitDecl();
205
206  return DC->getLexicalParent();
207}
208
209void Sema::PushDeclContext(Scope *S, DeclContext *DC) {
210  assert(getContainingDC(DC) == CurContext &&
211      "The next DeclContext should be lexically contained in the current one.");
212  CurContext = DC;
213  S->setEntity(DC);
214}
215
216void Sema::PopDeclContext() {
217  assert(CurContext && "DeclContext imbalance!");
218
219  CurContext = getContainingDC(CurContext);
220}
221
222/// \brief Determine whether we allow overloading of the function
223/// PrevDecl with another declaration.
224///
225/// This routine determines whether overloading is possible, not
226/// whether some new function is actually an overload. It will return
227/// true in C++ (where we can always provide overloads) or, as an
228/// extension, in C when the previous function is already an
229/// overloaded function declaration or has the "overloadable"
230/// attribute.
231static bool AllowOverloadingOfFunction(Decl *PrevDecl, ASTContext &Context) {
232  if (Context.getLangOptions().CPlusPlus)
233    return true;
234
235  if (isa<OverloadedFunctionDecl>(PrevDecl))
236    return true;
237
238  return PrevDecl->getAttr<OverloadableAttr>() != 0;
239}
240
241/// Add this decl to the scope shadowed decl chains.
242void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) {
243  // Move up the scope chain until we find the nearest enclosing
244  // non-transparent context. The declaration will be introduced into this
245  // scope.
246  while (S->getEntity() &&
247         ((DeclContext *)S->getEntity())->isTransparentContext())
248    S = S->getParent();
249
250  S->AddDecl(DeclPtrTy::make(D));
251
252  // Add scoped declarations into their context, so that they can be
253  // found later. Declarations without a context won't be inserted
254  // into any context.
255  CurContext->addDecl(Context, D);
256
257  // C++ [basic.scope]p4:
258  //   -- exactly one declaration shall declare a class name or
259  //   enumeration name that is not a typedef name and the other
260  //   declarations shall all refer to the same object or
261  //   enumerator, or all refer to functions and function templates;
262  //   in this case the class name or enumeration name is hidden.
263  if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
264    // We are pushing the name of a tag (enum or class).
265    if (CurContext->getLookupContext()
266          == TD->getDeclContext()->getLookupContext()) {
267      // We're pushing the tag into the current context, which might
268      // require some reshuffling in the identifier resolver.
269      IdentifierResolver::iterator
270        I = IdResolver.begin(TD->getDeclName()),
271        IEnd = IdResolver.end();
272      if (I != IEnd && isDeclInScope(*I, CurContext, S)) {
273        NamedDecl *PrevDecl = *I;
274        for (; I != IEnd && isDeclInScope(*I, CurContext, S);
275             PrevDecl = *I, ++I) {
276          if (TD->declarationReplaces(*I)) {
277            // This is a redeclaration. Remove it from the chain and
278            // break out, so that we'll add in the shadowed
279            // declaration.
280            S->RemoveDecl(DeclPtrTy::make(*I));
281            if (PrevDecl == *I) {
282              IdResolver.RemoveDecl(*I);
283              IdResolver.AddDecl(TD);
284              return;
285            } else {
286              IdResolver.RemoveDecl(*I);
287              break;
288            }
289          }
290        }
291
292        // There is already a declaration with the same name in the same
293        // scope, which is not a tag declaration. It must be found
294        // before we find the new declaration, so insert the new
295        // declaration at the end of the chain.
296        IdResolver.AddShadowedDecl(TD, PrevDecl);
297
298        return;
299      }
300    }
301  } else if (isa<FunctionDecl>(D) &&
302             AllowOverloadingOfFunction(D, Context)) {
303    // We are pushing the name of a function, which might be an
304    // overloaded name.
305    FunctionDecl *FD = cast<FunctionDecl>(D);
306    IdentifierResolver::iterator Redecl
307      = std::find_if(IdResolver.begin(FD->getDeclName()),
308                     IdResolver.end(),
309                     std::bind1st(std::mem_fun(&NamedDecl::declarationReplaces),
310                                  FD));
311    if (Redecl != IdResolver.end() &&
312        S->isDeclScope(DeclPtrTy::make(*Redecl))) {
313      // There is already a declaration of a function on our
314      // IdResolver chain. Replace it with this declaration.
315      S->RemoveDecl(DeclPtrTy::make(*Redecl));
316      IdResolver.RemoveDecl(*Redecl);
317    }
318  } else if (isa<ObjCInterfaceDecl>(D)) {
319    // We're pushing an Objective-C interface into the current
320    // context. If there is already an alias declaration, remove it first.
321    for (IdentifierResolver::iterator
322           I = IdResolver.begin(D->getDeclName()), IEnd = IdResolver.end();
323         I != IEnd; ++I) {
324      if (isa<ObjCCompatibleAliasDecl>(*I)) {
325        S->RemoveDecl(DeclPtrTy::make(*I));
326        IdResolver.RemoveDecl(*I);
327        break;
328      }
329    }
330  }
331
332  IdResolver.AddDecl(D);
333}
334
335void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) {
336  if (S->decl_empty()) return;
337  assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) &&
338	 "Scope shouldn't contain decls!");
339
340  for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end();
341       I != E; ++I) {
342    Decl *TmpD = (*I).getAs<Decl>();
343    assert(TmpD && "This decl didn't get pushed??");
344
345    assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?");
346    NamedDecl *D = cast<NamedDecl>(TmpD);
347
348    if (!D->getDeclName()) continue;
349
350    // Remove this name from our lexical scope.
351    IdResolver.RemoveDecl(D);
352  }
353}
354
355/// getObjCInterfaceDecl - Look up a for a class declaration in the scope.
356/// return 0 if one not found.
357ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) {
358  // The third "scope" argument is 0 since we aren't enabling lazy built-in
359  // creation from this context.
360  NamedDecl *IDecl = LookupName(TUScope, Id, LookupOrdinaryName);
361
362  return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl);
363}
364
365/// getNonFieldDeclScope - Retrieves the innermost scope, starting
366/// from S, where a non-field would be declared. This routine copes
367/// with the difference between C and C++ scoping rules in structs and
368/// unions. For example, the following code is well-formed in C but
369/// ill-formed in C++:
370/// @code
371/// struct S6 {
372///   enum { BAR } e;
373/// };
374///
375/// void test_S6() {
376///   struct S6 a;
377///   a.e = BAR;
378/// }
379/// @endcode
380/// For the declaration of BAR, this routine will return a different
381/// scope. The scope S will be the scope of the unnamed enumeration
382/// within S6. In C++, this routine will return the scope associated
383/// with S6, because the enumeration's scope is a transparent
384/// context but structures can contain non-field names. In C, this
385/// routine will return the translation unit scope, since the
386/// enumeration's scope is a transparent context and structures cannot
387/// contain non-field names.
388Scope *Sema::getNonFieldDeclScope(Scope *S) {
389  while (((S->getFlags() & Scope::DeclScope) == 0) ||
390         (S->getEntity() &&
391          ((DeclContext *)S->getEntity())->isTransparentContext()) ||
392         (S->isClassScope() && !getLangOptions().CPlusPlus))
393    S = S->getParent();
394  return S;
395}
396
397void Sema::InitBuiltinVaListType() {
398  if (!Context.getBuiltinVaListType().isNull())
399    return;
400
401  IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list");
402  NamedDecl *VaDecl = LookupName(TUScope, VaIdent, LookupOrdinaryName);
403  TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl);
404  Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef));
405}
406
407/// LazilyCreateBuiltin - The specified Builtin-ID was first used at
408/// file scope.  lazily create a decl for it. ForRedeclaration is true
409/// if we're creating this built-in in anticipation of redeclaring the
410/// built-in.
411NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid,
412                                     Scope *S, bool ForRedeclaration,
413                                     SourceLocation Loc) {
414  Builtin::ID BID = (Builtin::ID)bid;
415
416  if (Context.BuiltinInfo.hasVAListUse(BID))
417    InitBuiltinVaListType();
418
419  Builtin::Context::GetBuiltinTypeError Error;
420  QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context, Error);
421  switch (Error) {
422  case Builtin::Context::GE_None:
423    // Okay
424    break;
425
426  case Builtin::Context::GE_Missing_FILE:
427    if (ForRedeclaration)
428      Diag(Loc, diag::err_implicit_decl_requires_stdio)
429        << Context.BuiltinInfo.GetName(BID);
430    return 0;
431  }
432
433  if (!ForRedeclaration && Context.BuiltinInfo.isPredefinedLibFunction(BID)) {
434    Diag(Loc, diag::ext_implicit_lib_function_decl)
435      << Context.BuiltinInfo.GetName(BID)
436      << R;
437    if (Context.BuiltinInfo.getHeaderName(BID) &&
438        Diags.getDiagnosticLevel(diag::ext_implicit_lib_function_decl)
439          != Diagnostic::Ignored)
440      Diag(Loc, diag::note_please_include_header)
441        << Context.BuiltinInfo.getHeaderName(BID)
442        << Context.BuiltinInfo.GetName(BID);
443  }
444
445  FunctionDecl *New = FunctionDecl::Create(Context,
446                                           Context.getTranslationUnitDecl(),
447                                           Loc, II, R,
448                                           FunctionDecl::Extern, false,
449                                           /*hasPrototype=*/true);
450  New->setImplicit();
451
452  // Create Decl objects for each parameter, adding them to the
453  // FunctionDecl.
454  if (FunctionProtoType *FT = dyn_cast<FunctionProtoType>(R)) {
455    llvm::SmallVector<ParmVarDecl*, 16> Params;
456    for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i)
457      Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0,
458                                           FT->getArgType(i), VarDecl::None, 0));
459    New->setParams(Context, &Params[0], Params.size());
460  }
461
462  AddKnownFunctionAttributes(New);
463
464  // TUScope is the translation-unit scope to insert this function into.
465  // FIXME: This is hideous. We need to teach PushOnScopeChains to
466  // relate Scopes to DeclContexts, and probably eliminate CurContext
467  // entirely, but we're not there yet.
468  DeclContext *SavedContext = CurContext;
469  CurContext = Context.getTranslationUnitDecl();
470  PushOnScopeChains(New, TUScope);
471  CurContext = SavedContext;
472  return New;
473}
474
475/// GetStdNamespace - This method gets the C++ "std" namespace. This is where
476/// everything from the standard library is defined.
477NamespaceDecl *Sema::GetStdNamespace() {
478  if (!StdNamespace) {
479    IdentifierInfo *StdIdent = &PP.getIdentifierTable().get("std");
480    DeclContext *Global = Context.getTranslationUnitDecl();
481    Decl *Std = LookupQualifiedName(Global, StdIdent, LookupNamespaceName);
482    StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std);
483  }
484  return StdNamespace;
485}
486
487/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the
488/// same name and scope as a previous declaration 'Old'.  Figure out
489/// how to resolve this situation, merging decls or emitting
490/// diagnostics as appropriate. If there was an error, set New to be invalid.
491///
492void Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) {
493  // If either decl is known invalid already, set the new one to be invalid and
494  // don't bother doing any merging checks.
495  if (New->isInvalidDecl() || OldD->isInvalidDecl())
496    return New->setInvalidDecl();
497
498  bool objc_types = false;
499
500  // Allow multiple definitions for ObjC built-in typedefs.
501  // FIXME: Verify the underlying types are equivalent!
502  if (getLangOptions().ObjC1) {
503    const IdentifierInfo *TypeID = New->getIdentifier();
504    switch (TypeID->getLength()) {
505    default: break;
506    case 2:
507      if (!TypeID->isStr("id"))
508        break;
509      Context.setObjCIdType(Context.getTypeDeclType(New));
510      objc_types = true;
511      break;
512    case 5:
513      if (!TypeID->isStr("Class"))
514        break;
515      Context.setObjCClassType(Context.getTypeDeclType(New));
516      return;
517    case 3:
518      if (!TypeID->isStr("SEL"))
519        break;
520      Context.setObjCSelType(Context.getTypeDeclType(New));
521      return;
522    case 8:
523      if (!TypeID->isStr("Protocol"))
524        break;
525      Context.setObjCProtoType(New->getUnderlyingType());
526      return;
527    }
528    // Fall through - the typedef name was not a builtin type.
529  }
530  // Verify the old decl was also a type.
531  TypeDecl *Old = dyn_cast<TypeDecl>(OldD);
532  if (!Old) {
533    Diag(New->getLocation(), diag::err_redefinition_different_kind)
534      << New->getDeclName();
535    if (OldD->getLocation().isValid())
536      Diag(OldD->getLocation(), diag::note_previous_definition);
537    return New->setInvalidDecl();
538  }
539
540  // Determine the "old" type we'll use for checking and diagnostics.
541  QualType OldType;
542  if (TypedefDecl *OldTypedef = dyn_cast<TypedefDecl>(Old))
543    OldType = OldTypedef->getUnderlyingType();
544  else
545    OldType = Context.getTypeDeclType(Old);
546
547  // If the typedef types are not identical, reject them in all languages and
548  // with any extensions enabled.
549
550  if (OldType != New->getUnderlyingType() &&
551      Context.getCanonicalType(OldType) !=
552      Context.getCanonicalType(New->getUnderlyingType())) {
553    Diag(New->getLocation(), diag::err_redefinition_different_typedef)
554      << New->getUnderlyingType() << OldType;
555    if (Old->getLocation().isValid())
556      Diag(Old->getLocation(), diag::note_previous_definition);
557    return New->setInvalidDecl();
558  }
559
560  if (objc_types || getLangOptions().Microsoft)
561    return;
562
563  // C++ [dcl.typedef]p2:
564  //   In a given non-class scope, a typedef specifier can be used to
565  //   redefine the name of any type declared in that scope to refer
566  //   to the type to which it already refers.
567  if (getLangOptions().CPlusPlus) {
568    if (!isa<CXXRecordDecl>(CurContext))
569      return;
570    Diag(New->getLocation(), diag::err_redefinition)
571      << New->getDeclName();
572    Diag(Old->getLocation(), diag::note_previous_definition);
573    return New->setInvalidDecl();
574  }
575
576  // If we have a redefinition of a typedef in C, emit a warning.  This warning
577  // is normally mapped to an error, but can be controlled with
578  // -Wtypedef-redefinition.  If either the original was in a system header,
579  // don't emit this for compatibility with GCC.
580  if (PP.getDiagnostics().getSuppressSystemWarnings() &&
581      Context.getSourceManager().isInSystemHeader(Old->getLocation()))
582    return;
583
584  Diag(New->getLocation(), diag::warn_redefinition_of_typedef)
585    << New->getDeclName();
586  Diag(Old->getLocation(), diag::note_previous_definition);
587  return;
588}
589
590/// DeclhasAttr - returns true if decl Declaration already has the target
591/// attribute.
592static bool DeclHasAttr(const Decl *decl, const Attr *target) {
593  for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext())
594    if (attr->getKind() == target->getKind())
595      return true;
596
597  return false;
598}
599
600/// MergeAttributes - append attributes from the Old decl to the New one.
601static void MergeAttributes(Decl *New, Decl *Old, ASTContext &C) {
602  for (const Attr *attr = Old->getAttrs(); attr; attr = attr->getNext()) {
603    if (!DeclHasAttr(New, attr) && attr->isMerged()) {
604      Attr *NewAttr = attr->clone(C);
605      NewAttr->setInherited(true);
606      New->addAttr(NewAttr);
607    }
608  }
609}
610
611/// Used in MergeFunctionDecl to keep track of function parameters in
612/// C.
613struct GNUCompatibleParamWarning {
614  ParmVarDecl *OldParm;
615  ParmVarDecl *NewParm;
616  QualType PromotedType;
617};
618
619/// MergeFunctionDecl - We just parsed a function 'New' from
620/// declarator D which has the same name and scope as a previous
621/// declaration 'Old'.  Figure out how to resolve this situation,
622/// merging decls or emitting diagnostics as appropriate.
623///
624/// In C++, New and Old must be declarations that are not
625/// overloaded. Use IsOverload to determine whether New and Old are
626/// overloaded, and to select the Old declaration that New should be
627/// merged with.
628///
629/// Returns true if there was an error, false otherwise.
630bool Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD) {
631  assert(!isa<OverloadedFunctionDecl>(OldD) &&
632         "Cannot merge with an overloaded function declaration");
633
634  // Verify the old decl was also a function.
635  FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD);
636  if (!Old) {
637    Diag(New->getLocation(), diag::err_redefinition_different_kind)
638      << New->getDeclName();
639    Diag(OldD->getLocation(), diag::note_previous_definition);
640    return true;
641  }
642
643  // Determine whether the previous declaration was a definition,
644  // implicit declaration, or a declaration.
645  diag::kind PrevDiag;
646  if (Old->isThisDeclarationADefinition())
647    PrevDiag = diag::note_previous_definition;
648  else if (Old->isImplicit())
649    PrevDiag = diag::note_previous_implicit_declaration;
650  else
651    PrevDiag = diag::note_previous_declaration;
652
653  QualType OldQType = Context.getCanonicalType(Old->getType());
654  QualType NewQType = Context.getCanonicalType(New->getType());
655
656  if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) &&
657      New->getStorageClass() == FunctionDecl::Static &&
658      Old->getStorageClass() != FunctionDecl::Static) {
659    Diag(New->getLocation(), diag::err_static_non_static)
660      << New;
661    Diag(Old->getLocation(), PrevDiag);
662    return true;
663  }
664
665  if (getLangOptions().CPlusPlus) {
666    // (C++98 13.1p2):
667    //   Certain function declarations cannot be overloaded:
668    //     -- Function declarations that differ only in the return type
669    //        cannot be overloaded.
670    QualType OldReturnType
671      = cast<FunctionType>(OldQType.getTypePtr())->getResultType();
672    QualType NewReturnType
673      = cast<FunctionType>(NewQType.getTypePtr())->getResultType();
674    if (OldReturnType != NewReturnType) {
675      Diag(New->getLocation(), diag::err_ovl_diff_return_type);
676      Diag(Old->getLocation(), PrevDiag) << Old << Old->getType();
677      return true;
678    }
679
680    const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old);
681    const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New);
682    if (OldMethod && NewMethod &&
683        OldMethod->getLexicalDeclContext() ==
684          NewMethod->getLexicalDeclContext()) {
685      //    -- Member function declarations with the same name and the
686      //       same parameter types cannot be overloaded if any of them
687      //       is a static member function declaration.
688      if (OldMethod->isStatic() || NewMethod->isStatic()) {
689        Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member);
690        Diag(Old->getLocation(), PrevDiag) << Old << Old->getType();
691        return true;
692      }
693
694      // C++ [class.mem]p1:
695      //   [...] A member shall not be declared twice in the
696      //   member-specification, except that a nested class or member
697      //   class template can be declared and then later defined.
698      unsigned NewDiag;
699      if (isa<CXXConstructorDecl>(OldMethod))
700        NewDiag = diag::err_constructor_redeclared;
701      else if (isa<CXXDestructorDecl>(NewMethod))
702        NewDiag = diag::err_destructor_redeclared;
703      else if (isa<CXXConversionDecl>(NewMethod))
704        NewDiag = diag::err_conv_function_redeclared;
705      else
706        NewDiag = diag::err_member_redeclared;
707
708      Diag(New->getLocation(), NewDiag);
709      Diag(Old->getLocation(), PrevDiag) << Old << Old->getType();
710    }
711
712    // (C++98 8.3.5p3):
713    //   All declarations for a function shall agree exactly in both the
714    //   return type and the parameter-type-list.
715    if (OldQType == NewQType)
716      return MergeCompatibleFunctionDecls(New, Old);
717
718    // Fall through for conflicting redeclarations and redefinitions.
719  }
720
721  // C: Function types need to be compatible, not identical. This handles
722  // duplicate function decls like "void f(int); void f(enum X);" properly.
723  if (!getLangOptions().CPlusPlus &&
724      Context.typesAreCompatible(OldQType, NewQType)) {
725    const FunctionType *OldFuncType = OldQType->getAsFunctionType();
726    const FunctionType *NewFuncType = NewQType->getAsFunctionType();
727    const FunctionProtoType *OldProto = 0;
728    if (isa<FunctionNoProtoType>(NewFuncType) &&
729        (OldProto = dyn_cast<FunctionProtoType>(OldFuncType))) {
730      // The old declaration provided a function prototype, but the
731      // new declaration does not. Merge in the prototype.
732      llvm::SmallVector<QualType, 16> ParamTypes(OldProto->arg_type_begin(),
733                                                 OldProto->arg_type_end());
734      NewQType = Context.getFunctionType(NewFuncType->getResultType(),
735                                         &ParamTypes[0], ParamTypes.size(),
736                                         OldProto->isVariadic(),
737                                         OldProto->getTypeQuals());
738      New->setType(NewQType);
739      New->setInheritedPrototype();
740
741      // Synthesize a parameter for each argument type.
742      llvm::SmallVector<ParmVarDecl*, 16> Params;
743      for (FunctionProtoType::arg_type_iterator
744             ParamType = OldProto->arg_type_begin(),
745             ParamEnd = OldProto->arg_type_end();
746           ParamType != ParamEnd; ++ParamType) {
747        ParmVarDecl *Param = ParmVarDecl::Create(Context, New,
748                                                 SourceLocation(), 0,
749                                                 *ParamType, VarDecl::None,
750                                                 0);
751        Param->setImplicit();
752        Params.push_back(Param);
753      }
754
755      New->setParams(Context, &Params[0], Params.size());
756    }
757
758    return MergeCompatibleFunctionDecls(New, Old);
759  }
760
761  // GNU C permits a K&R definition to follow a prototype declaration
762  // if the declared types of the parameters in the K&R definition
763  // match the types in the prototype declaration, even when the
764  // promoted types of the parameters from the K&R definition differ
765  // from the types in the prototype. GCC then keeps the types from
766  // the prototype.
767  if (!getLangOptions().CPlusPlus &&
768      Old->hasPrototype() && !New->hasPrototype() &&
769      New->getType()->getAsFunctionProtoType() &&
770      Old->getNumParams() == New->getNumParams()) {
771    llvm::SmallVector<QualType, 16> ArgTypes;
772    llvm::SmallVector<GNUCompatibleParamWarning, 16> Warnings;
773    const FunctionProtoType *OldProto
774      = Old->getType()->getAsFunctionProtoType();
775    const FunctionProtoType *NewProto
776      = New->getType()->getAsFunctionProtoType();
777
778    // Determine whether this is the GNU C extension.
779    bool GNUCompatible =
780      Context.typesAreCompatible(OldProto->getResultType(),
781                                 NewProto->getResultType()) &&
782      (OldProto->isVariadic() == NewProto->isVariadic());
783    for (unsigned Idx = 0, End = Old->getNumParams();
784         GNUCompatible && Idx != End; ++Idx) {
785      ParmVarDecl *OldParm = Old->getParamDecl(Idx);
786      ParmVarDecl *NewParm = New->getParamDecl(Idx);
787      if (Context.typesAreCompatible(OldParm->getType(),
788                                     NewProto->getArgType(Idx))) {
789        ArgTypes.push_back(NewParm->getType());
790      } else if (Context.typesAreCompatible(OldParm->getType(),
791                                            NewParm->getType())) {
792        GNUCompatibleParamWarning Warn
793          = { OldParm, NewParm, NewProto->getArgType(Idx) };
794        Warnings.push_back(Warn);
795        ArgTypes.push_back(NewParm->getType());
796      } else
797        GNUCompatible = false;
798    }
799
800    if (GNUCompatible) {
801      for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) {
802        Diag(Warnings[Warn].NewParm->getLocation(),
803             diag::ext_param_promoted_not_compatible_with_prototype)
804          << Warnings[Warn].PromotedType
805          << Warnings[Warn].OldParm->getType();
806        Diag(Warnings[Warn].OldParm->getLocation(),
807             diag::note_previous_declaration);
808      }
809
810      New->setType(Context.getFunctionType(NewProto->getResultType(),
811                                           &ArgTypes[0], ArgTypes.size(),
812                                           NewProto->isVariadic(),
813                                           NewProto->getTypeQuals()));
814      return MergeCompatibleFunctionDecls(New, Old);
815    }
816
817    // Fall through to diagnose conflicting types.
818  }
819
820  // A function that has already been declared has been redeclared or defined
821  // with a different type- show appropriate diagnostic
822  if (unsigned BuiltinID = Old->getBuiltinID(Context)) {
823    // The user has declared a builtin function with an incompatible
824    // signature.
825    if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) {
826      // The function the user is redeclaring is a library-defined
827      // function like 'malloc' or 'printf'. Warn about the
828      // redeclaration, then pretend that we don't know about this
829      // library built-in.
830      Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New;
831      Diag(Old->getLocation(), diag::note_previous_builtin_declaration)
832        << Old << Old->getType();
833      New->getIdentifier()->setBuiltinID(Builtin::NotBuiltin);
834      Old->setInvalidDecl();
835      return false;
836    }
837
838    PrevDiag = diag::note_previous_builtin_declaration;
839  }
840
841  Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName();
842  Diag(Old->getLocation(), PrevDiag) << Old << Old->getType();
843  return true;
844}
845
846/// \brief Completes the merge of two function declarations that are
847/// known to be compatible.
848///
849/// This routine handles the merging of attributes and other
850/// properties of function declarations form the old declaration to
851/// the new declaration, once we know that New is in fact a
852/// redeclaration of Old.
853///
854/// \returns false
855bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old) {
856  // Merge the attributes
857  MergeAttributes(New, Old, Context);
858
859  // Merge the storage class.
860  if (Old->getStorageClass() != FunctionDecl::Extern)
861    New->setStorageClass(Old->getStorageClass());
862
863  // Merge "inline"
864  if (Old->isInline())
865    New->setInline(true);
866
867  // If this function declaration by itself qualifies as a C99 inline
868  // definition (C99 6.7.4p6), but the previous definition did not,
869  // then the function is not a C99 inline definition.
870  if (New->isC99InlineDefinition() && !Old->isC99InlineDefinition())
871    New->setC99InlineDefinition(false);
872  else if (Old->isC99InlineDefinition() && !New->isC99InlineDefinition()) {
873    // Mark all preceding definitions as not being C99 inline definitions.
874    for (const FunctionDecl *Prev = Old; Prev;
875         Prev = Prev->getPreviousDeclaration())
876      const_cast<FunctionDecl *>(Prev)->setC99InlineDefinition(false);
877  }
878
879  // Merge "pure" flag.
880  if (Old->isPure())
881    New->setPure();
882
883  // Merge the "deleted" flag.
884  if (Old->isDeleted())
885    New->setDeleted();
886
887  if (getLangOptions().CPlusPlus)
888    return MergeCXXFunctionDecl(New, Old);
889
890  return false;
891}
892
893/// MergeVarDecl - We just parsed a variable 'New' which has the same name
894/// and scope as a previous declaration 'Old'.  Figure out how to resolve this
895/// situation, merging decls or emitting diagnostics as appropriate.
896///
897/// Tentative definition rules (C99 6.9.2p2) are checked by
898/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative
899/// definitions here, since the initializer hasn't been attached.
900///
901void Sema::MergeVarDecl(VarDecl *New, Decl *OldD) {
902  // If either decl is invalid, make sure the new one is marked invalid and
903  // don't do any other checking.
904  if (New->isInvalidDecl() || OldD->isInvalidDecl())
905    return New->setInvalidDecl();
906
907  // Verify the old decl was also a variable.
908  VarDecl *Old = dyn_cast<VarDecl>(OldD);
909  if (!Old) {
910    Diag(New->getLocation(), diag::err_redefinition_different_kind)
911      << New->getDeclName();
912    Diag(OldD->getLocation(), diag::note_previous_definition);
913    return New->setInvalidDecl();
914  }
915
916  MergeAttributes(New, Old, Context);
917
918  // Merge the types
919  QualType MergedT = Context.mergeTypes(New->getType(), Old->getType());
920  if (MergedT.isNull()) {
921    Diag(New->getLocation(), diag::err_redefinition_different_type)
922      << New->getDeclName();
923    Diag(Old->getLocation(), diag::note_previous_definition);
924    return New->setInvalidDecl();
925  }
926  New->setType(MergedT);
927
928  // C99 6.2.2p4: Check if we have a static decl followed by a non-static.
929  if (New->getStorageClass() == VarDecl::Static &&
930      (Old->getStorageClass() == VarDecl::None || Old->hasExternalStorage())) {
931    Diag(New->getLocation(), diag::err_static_non_static) << New->getDeclName();
932    Diag(Old->getLocation(), diag::note_previous_definition);
933    return New->setInvalidDecl();
934  }
935  // C99 6.2.2p4:
936  //   For an identifier declared with the storage-class specifier
937  //   extern in a scope in which a prior declaration of that
938  //   identifier is visible,23) if the prior declaration specifies
939  //   internal or external linkage, the linkage of the identifier at
940  //   the later declaration is the same as the linkage specified at
941  //   the prior declaration. If no prior declaration is visible, or
942  //   if the prior declaration specifies no linkage, then the
943  //   identifier has external linkage.
944  if (New->hasExternalStorage() && Old->hasLinkage())
945    /* Okay */;
946  else if (New->getStorageClass() != VarDecl::Static &&
947           Old->getStorageClass() == VarDecl::Static) {
948    Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName();
949    Diag(Old->getLocation(), diag::note_previous_definition);
950    return New->setInvalidDecl();
951  }
952
953  // Variables with external linkage are analyzed in FinalizeDeclaratorGroup.
954
955  // FIXME: The test for external storage here seems wrong? We still
956  // need to check for mismatches.
957  if (!New->hasExternalStorage() && !New->isFileVarDecl() &&
958      // Don't complain about out-of-line definitions of static members.
959      !(Old->getLexicalDeclContext()->isRecord() &&
960        !New->getLexicalDeclContext()->isRecord())) {
961    Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName();
962    Diag(Old->getLocation(), diag::note_previous_definition);
963    return New->setInvalidDecl();
964  }
965
966  if (New->isThreadSpecified() && !Old->isThreadSpecified()) {
967    Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName();
968    Diag(Old->getLocation(), diag::note_previous_definition);
969  } else if (!New->isThreadSpecified() && Old->isThreadSpecified()) {
970    Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName();
971    Diag(Old->getLocation(), diag::note_previous_definition);
972  }
973
974  // Keep a chain of previous declarations.
975  New->setPreviousDeclaration(Old);
976}
977
978/// CheckParmsForFunctionDef - Check that the parameters of the given
979/// function are appropriate for the definition of a function. This
980/// takes care of any checks that cannot be performed on the
981/// declaration itself, e.g., that the types of each of the function
982/// parameters are complete.
983bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) {
984  bool HasInvalidParm = false;
985  for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) {
986    ParmVarDecl *Param = FD->getParamDecl(p);
987
988    // C99 6.7.5.3p4: the parameters in a parameter type list in a
989    // function declarator that is part of a function definition of
990    // that function shall not have incomplete type.
991    //
992    // This is also C++ [dcl.fct]p6.
993    if (!Param->isInvalidDecl() &&
994        RequireCompleteType(Param->getLocation(), Param->getType(),
995                               diag::err_typecheck_decl_incomplete_type)) {
996      Param->setInvalidDecl();
997      HasInvalidParm = true;
998    }
999
1000    // C99 6.9.1p5: If the declarator includes a parameter type list, the
1001    // declaration of each parameter shall include an identifier.
1002    if (Param->getIdentifier() == 0 &&
1003        !Param->isImplicit() &&
1004        !getLangOptions().CPlusPlus)
1005      Diag(Param->getLocation(), diag::err_parameter_name_omitted);
1006  }
1007
1008  return HasInvalidParm;
1009}
1010
1011/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
1012/// no declarator (e.g. "struct foo;") is parsed.
1013Sema::DeclPtrTy Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) {
1014  // FIXME: Error on auto/register at file scope
1015  // FIXME: Error on inline/virtual/explicit
1016  // FIXME: Error on invalid restrict
1017  // FIXME: Warn on useless __thread
1018  // FIXME: Warn on useless const/volatile
1019  // FIXME: Warn on useless static/extern/typedef/private_extern/mutable
1020  // FIXME: Warn on useless attributes
1021
1022  TagDecl *Tag = 0;
1023  if (DS.getTypeSpecType() == DeclSpec::TST_class ||
1024      DS.getTypeSpecType() == DeclSpec::TST_struct ||
1025      DS.getTypeSpecType() == DeclSpec::TST_union ||
1026      DS.getTypeSpecType() == DeclSpec::TST_enum)
1027    Tag = dyn_cast<TagDecl>(static_cast<Decl *>(DS.getTypeRep()));
1028
1029  if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) {
1030    if (!Record->getDeclName() && Record->isDefinition() &&
1031        DS.getStorageClassSpec() != DeclSpec::SCS_typedef) {
1032      if (getLangOptions().CPlusPlus ||
1033          Record->getDeclContext()->isRecord())
1034        return BuildAnonymousStructOrUnion(S, DS, Record);
1035
1036      Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators)
1037        << DS.getSourceRange();
1038    }
1039
1040    // Microsoft allows unnamed struct/union fields. Don't complain
1041    // about them.
1042    // FIXME: Should we support Microsoft's extensions in this area?
1043    if (Record->getDeclName() && getLangOptions().Microsoft)
1044      return DeclPtrTy::make(Tag);
1045  }
1046
1047  if (!DS.isMissingDeclaratorOk() &&
1048      DS.getTypeSpecType() != DeclSpec::TST_error) {
1049    // Warn about typedefs of enums without names, since this is an
1050    // extension in both Microsoft an GNU.
1051    if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef &&
1052        Tag && isa<EnumDecl>(Tag)) {
1053      Diag(DS.getSourceRange().getBegin(), diag::ext_typedef_without_a_name)
1054        << DS.getSourceRange();
1055      return DeclPtrTy::make(Tag);
1056    }
1057
1058    Diag(DS.getSourceRange().getBegin(), diag::err_no_declarators)
1059      << DS.getSourceRange();
1060    return DeclPtrTy();
1061  }
1062
1063  return DeclPtrTy::make(Tag);
1064}
1065
1066/// InjectAnonymousStructOrUnionMembers - Inject the members of the
1067/// anonymous struct or union AnonRecord into the owning context Owner
1068/// and scope S. This routine will be invoked just after we realize
1069/// that an unnamed union or struct is actually an anonymous union or
1070/// struct, e.g.,
1071///
1072/// @code
1073/// union {
1074///   int i;
1075///   float f;
1076/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and
1077///    // f into the surrounding scope.x
1078/// @endcode
1079///
1080/// This routine is recursive, injecting the names of nested anonymous
1081/// structs/unions into the owning context and scope as well.
1082bool Sema::InjectAnonymousStructOrUnionMembers(Scope *S, DeclContext *Owner,
1083                                               RecordDecl *AnonRecord) {
1084  bool Invalid = false;
1085  for (RecordDecl::field_iterator F = AnonRecord->field_begin(Context),
1086                               FEnd = AnonRecord->field_end(Context);
1087       F != FEnd; ++F) {
1088    if ((*F)->getDeclName()) {
1089      NamedDecl *PrevDecl = LookupQualifiedName(Owner, (*F)->getDeclName(),
1090                                                LookupOrdinaryName, true);
1091      if (PrevDecl && !isa<TagDecl>(PrevDecl)) {
1092        // C++ [class.union]p2:
1093        //   The names of the members of an anonymous union shall be
1094        //   distinct from the names of any other entity in the
1095        //   scope in which the anonymous union is declared.
1096        unsigned diagKind
1097          = AnonRecord->isUnion()? diag::err_anonymous_union_member_redecl
1098                                 : diag::err_anonymous_struct_member_redecl;
1099        Diag((*F)->getLocation(), diagKind)
1100          << (*F)->getDeclName();
1101        Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
1102        Invalid = true;
1103      } else {
1104        // C++ [class.union]p2:
1105        //   For the purpose of name lookup, after the anonymous union
1106        //   definition, the members of the anonymous union are
1107        //   considered to have been defined in the scope in which the
1108        //   anonymous union is declared.
1109        Owner->makeDeclVisibleInContext(Context, *F);
1110        S->AddDecl(DeclPtrTy::make(*F));
1111        IdResolver.AddDecl(*F);
1112      }
1113    } else if (const RecordType *InnerRecordType
1114                 = (*F)->getType()->getAsRecordType()) {
1115      RecordDecl *InnerRecord = InnerRecordType->getDecl();
1116      if (InnerRecord->isAnonymousStructOrUnion())
1117        Invalid = Invalid ||
1118          InjectAnonymousStructOrUnionMembers(S, Owner, InnerRecord);
1119    }
1120  }
1121
1122  return Invalid;
1123}
1124
1125/// ActOnAnonymousStructOrUnion - Handle the declaration of an
1126/// anonymous structure or union. Anonymous unions are a C++ feature
1127/// (C++ [class.union]) and a GNU C extension; anonymous structures
1128/// are a GNU C and GNU C++ extension.
1129Sema::DeclPtrTy Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
1130                                                  RecordDecl *Record) {
1131  DeclContext *Owner = Record->getDeclContext();
1132
1133  // Diagnose whether this anonymous struct/union is an extension.
1134  if (Record->isUnion() && !getLangOptions().CPlusPlus)
1135    Diag(Record->getLocation(), diag::ext_anonymous_union);
1136  else if (!Record->isUnion())
1137    Diag(Record->getLocation(), diag::ext_anonymous_struct);
1138
1139  // C and C++ require different kinds of checks for anonymous
1140  // structs/unions.
1141  bool Invalid = false;
1142  if (getLangOptions().CPlusPlus) {
1143    const char* PrevSpec = 0;
1144    // C++ [class.union]p3:
1145    //   Anonymous unions declared in a named namespace or in the
1146    //   global namespace shall be declared static.
1147    if (DS.getStorageClassSpec() != DeclSpec::SCS_static &&
1148        (isa<TranslationUnitDecl>(Owner) ||
1149         (isa<NamespaceDecl>(Owner) &&
1150          cast<NamespaceDecl>(Owner)->getDeclName()))) {
1151      Diag(Record->getLocation(), diag::err_anonymous_union_not_static);
1152      Invalid = true;
1153
1154      // Recover by adding 'static'.
1155      DS.SetStorageClassSpec(DeclSpec::SCS_static, SourceLocation(), PrevSpec);
1156    }
1157    // C++ [class.union]p3:
1158    //   A storage class is not allowed in a declaration of an
1159    //   anonymous union in a class scope.
1160    else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
1161             isa<RecordDecl>(Owner)) {
1162      Diag(DS.getStorageClassSpecLoc(),
1163           diag::err_anonymous_union_with_storage_spec);
1164      Invalid = true;
1165
1166      // Recover by removing the storage specifier.
1167      DS.SetStorageClassSpec(DeclSpec::SCS_unspecified, SourceLocation(),
1168                             PrevSpec);
1169    }
1170
1171    // C++ [class.union]p2:
1172    //   The member-specification of an anonymous union shall only
1173    //   define non-static data members. [Note: nested types and
1174    //   functions cannot be declared within an anonymous union. ]
1175    for (DeclContext::decl_iterator Mem = Record->decls_begin(Context),
1176                                 MemEnd = Record->decls_end(Context);
1177         Mem != MemEnd; ++Mem) {
1178      if (FieldDecl *FD = dyn_cast<FieldDecl>(*Mem)) {
1179        // C++ [class.union]p3:
1180        //   An anonymous union shall not have private or protected
1181        //   members (clause 11).
1182        if (FD->getAccess() == AS_protected || FD->getAccess() == AS_private) {
1183          Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member)
1184            << (int)Record->isUnion() << (int)(FD->getAccess() == AS_protected);
1185          Invalid = true;
1186        }
1187      } else if ((*Mem)->isImplicit()) {
1188        // Any implicit members are fine.
1189      } else if (isa<TagDecl>(*Mem) && (*Mem)->getDeclContext() != Record) {
1190        // This is a type that showed up in an
1191        // elaborated-type-specifier inside the anonymous struct or
1192        // union, but which actually declares a type outside of the
1193        // anonymous struct or union. It's okay.
1194      } else if (RecordDecl *MemRecord = dyn_cast<RecordDecl>(*Mem)) {
1195        if (!MemRecord->isAnonymousStructOrUnion() &&
1196            MemRecord->getDeclName()) {
1197          // This is a nested type declaration.
1198          Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type)
1199            << (int)Record->isUnion();
1200          Invalid = true;
1201        }
1202      } else {
1203        // We have something that isn't a non-static data
1204        // member. Complain about it.
1205        unsigned DK = diag::err_anonymous_record_bad_member;
1206        if (isa<TypeDecl>(*Mem))
1207          DK = diag::err_anonymous_record_with_type;
1208        else if (isa<FunctionDecl>(*Mem))
1209          DK = diag::err_anonymous_record_with_function;
1210        else if (isa<VarDecl>(*Mem))
1211          DK = diag::err_anonymous_record_with_static;
1212        Diag((*Mem)->getLocation(), DK)
1213            << (int)Record->isUnion();
1214          Invalid = true;
1215      }
1216    }
1217  }
1218
1219  if (!Record->isUnion() && !Owner->isRecord()) {
1220    Diag(Record->getLocation(), diag::err_anonymous_struct_not_member)
1221      << (int)getLangOptions().CPlusPlus;
1222    Invalid = true;
1223  }
1224
1225  // Create a declaration for this anonymous struct/union.
1226  NamedDecl *Anon = 0;
1227  if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) {
1228    Anon = FieldDecl::Create(Context, OwningClass, Record->getLocation(),
1229                             /*IdentifierInfo=*/0,
1230                             Context.getTypeDeclType(Record),
1231                             /*BitWidth=*/0, /*Mutable=*/false);
1232    Anon->setAccess(AS_public);
1233    if (getLangOptions().CPlusPlus)
1234      FieldCollector->Add(cast<FieldDecl>(Anon));
1235  } else {
1236    VarDecl::StorageClass SC;
1237    switch (DS.getStorageClassSpec()) {
1238    default: assert(0 && "Unknown storage class!");
1239    case DeclSpec::SCS_unspecified:    SC = VarDecl::None; break;
1240    case DeclSpec::SCS_extern:         SC = VarDecl::Extern; break;
1241    case DeclSpec::SCS_static:         SC = VarDecl::Static; break;
1242    case DeclSpec::SCS_auto:           SC = VarDecl::Auto; break;
1243    case DeclSpec::SCS_register:       SC = VarDecl::Register; break;
1244    case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break;
1245    case DeclSpec::SCS_mutable:
1246      // mutable can only appear on non-static class members, so it's always
1247      // an error here
1248      Diag(Record->getLocation(), diag::err_mutable_nonmember);
1249      Invalid = true;
1250      SC = VarDecl::None;
1251      break;
1252    }
1253
1254    Anon = VarDecl::Create(Context, Owner, Record->getLocation(),
1255                           /*IdentifierInfo=*/0,
1256                           Context.getTypeDeclType(Record),
1257                           SC, DS.getSourceRange().getBegin());
1258  }
1259  Anon->setImplicit();
1260
1261  // Add the anonymous struct/union object to the current
1262  // context. We'll be referencing this object when we refer to one of
1263  // its members.
1264  Owner->addDecl(Context, Anon);
1265
1266  // Inject the members of the anonymous struct/union into the owning
1267  // context and into the identifier resolver chain for name lookup
1268  // purposes.
1269  if (InjectAnonymousStructOrUnionMembers(S, Owner, Record))
1270    Invalid = true;
1271
1272  // Mark this as an anonymous struct/union type. Note that we do not
1273  // do this until after we have already checked and injected the
1274  // members of this anonymous struct/union type, because otherwise
1275  // the members could be injected twice: once by DeclContext when it
1276  // builds its lookup table, and once by
1277  // InjectAnonymousStructOrUnionMembers.
1278  Record->setAnonymousStructOrUnion(true);
1279
1280  if (Invalid)
1281    Anon->setInvalidDecl();
1282
1283  return DeclPtrTy::make(Anon);
1284}
1285
1286
1287/// GetNameForDeclarator - Determine the full declaration name for the
1288/// given Declarator.
1289DeclarationName Sema::GetNameForDeclarator(Declarator &D) {
1290  switch (D.getKind()) {
1291  case Declarator::DK_Abstract:
1292    assert(D.getIdentifier() == 0 && "abstract declarators have no name");
1293    return DeclarationName();
1294
1295  case Declarator::DK_Normal:
1296    assert (D.getIdentifier() != 0 && "normal declarators have an identifier");
1297    return DeclarationName(D.getIdentifier());
1298
1299  case Declarator::DK_Constructor: {
1300    QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType());
1301    Ty = Context.getCanonicalType(Ty);
1302    return Context.DeclarationNames.getCXXConstructorName(Ty);
1303  }
1304
1305  case Declarator::DK_Destructor: {
1306    QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType());
1307    Ty = Context.getCanonicalType(Ty);
1308    return Context.DeclarationNames.getCXXDestructorName(Ty);
1309  }
1310
1311  case Declarator::DK_Conversion: {
1312    // FIXME: We'd like to keep the non-canonical type for diagnostics!
1313    QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType());
1314    Ty = Context.getCanonicalType(Ty);
1315    return Context.DeclarationNames.getCXXConversionFunctionName(Ty);
1316  }
1317
1318  case Declarator::DK_Operator:
1319    assert(D.getIdentifier() == 0 && "operator names have no identifier");
1320    return Context.DeclarationNames.getCXXOperatorName(
1321                                                D.getOverloadedOperator());
1322  }
1323
1324  assert(false && "Unknown name kind");
1325  return DeclarationName();
1326}
1327
1328/// isNearlyMatchingFunction - Determine whether the C++ functions
1329/// Declaration and Definition are "nearly" matching. This heuristic
1330/// is used to improve diagnostics in the case where an out-of-line
1331/// function definition doesn't match any declaration within
1332/// the class or namespace.
1333static bool isNearlyMatchingFunction(ASTContext &Context,
1334                                     FunctionDecl *Declaration,
1335                                     FunctionDecl *Definition) {
1336  if (Declaration->param_size() != Definition->param_size())
1337    return false;
1338  for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) {
1339    QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType();
1340    QualType DefParamTy = Definition->getParamDecl(Idx)->getType();
1341
1342    DeclParamTy = Context.getCanonicalType(DeclParamTy.getNonReferenceType());
1343    DefParamTy = Context.getCanonicalType(DefParamTy.getNonReferenceType());
1344    if (DeclParamTy.getUnqualifiedType() != DefParamTy.getUnqualifiedType())
1345      return false;
1346  }
1347
1348  return true;
1349}
1350
1351Sema::DeclPtrTy
1352Sema::ActOnDeclarator(Scope *S, Declarator &D, bool IsFunctionDefinition) {
1353  DeclarationName Name = GetNameForDeclarator(D);
1354
1355  // All of these full declarators require an identifier.  If it doesn't have
1356  // one, the ParsedFreeStandingDeclSpec action should be used.
1357  if (!Name) {
1358    if (!D.isInvalidType())  // Reject this if we think it is valid.
1359      Diag(D.getDeclSpec().getSourceRange().getBegin(),
1360           diag::err_declarator_need_ident)
1361        << D.getDeclSpec().getSourceRange() << D.getSourceRange();
1362    return DeclPtrTy();
1363  }
1364
1365  // The scope passed in may not be a decl scope.  Zip up the scope tree until
1366  // we find one that is.
1367  while ((S->getFlags() & Scope::DeclScope) == 0 ||
1368         (S->getFlags() & Scope::TemplateParamScope) != 0)
1369    S = S->getParent();
1370
1371  DeclContext *DC;
1372  NamedDecl *PrevDecl;
1373  NamedDecl *New;
1374
1375  QualType R = GetTypeForDeclarator(D, S);
1376
1377  // See if this is a redefinition of a variable in the same scope.
1378  if (D.getCXXScopeSpec().isInvalid()) {
1379    DC = CurContext;
1380    PrevDecl = 0;
1381    D.setInvalidType();
1382  } else if (!D.getCXXScopeSpec().isSet()) {
1383    LookupNameKind NameKind = LookupOrdinaryName;
1384
1385    // If the declaration we're planning to build will be a function
1386    // or object with linkage, then look for another declaration with
1387    // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6).
1388    if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef)
1389      /* Do nothing*/;
1390    else if (R->isFunctionType()) {
1391      if (CurContext->isFunctionOrMethod())
1392        NameKind = LookupRedeclarationWithLinkage;
1393    } else if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern)
1394      NameKind = LookupRedeclarationWithLinkage;
1395
1396    DC = CurContext;
1397    PrevDecl = LookupName(S, Name, NameKind, true,
1398                          D.getDeclSpec().getStorageClassSpec() !=
1399                            DeclSpec::SCS_static,
1400                          D.getIdentifierLoc());
1401  } else { // Something like "int foo::x;"
1402    DC = computeDeclContext(D.getCXXScopeSpec());
1403    // FIXME: RequireCompleteDeclContext(D.getCXXScopeSpec()); ?
1404    PrevDecl = LookupQualifiedName(DC, Name, LookupOrdinaryName, true);
1405
1406    // C++ 7.3.1.2p2:
1407    // Members (including explicit specializations of templates) of a named
1408    // namespace can also be defined outside that namespace by explicit
1409    // qualification of the name being defined, provided that the entity being
1410    // defined was already declared in the namespace and the definition appears
1411    // after the point of declaration in a namespace that encloses the
1412    // declarations namespace.
1413    //
1414    // Note that we only check the context at this point. We don't yet
1415    // have enough information to make sure that PrevDecl is actually
1416    // the declaration we want to match. For example, given:
1417    //
1418    //   class X {
1419    //     void f();
1420    //     void f(float);
1421    //   };
1422    //
1423    //   void X::f(int) { } // ill-formed
1424    //
1425    // In this case, PrevDecl will point to the overload set
1426    // containing the two f's declared in X, but neither of them
1427    // matches.
1428
1429    // First check whether we named the global scope.
1430    if (isa<TranslationUnitDecl>(DC)) {
1431      Diag(D.getIdentifierLoc(), diag::err_invalid_declarator_global_scope)
1432        << Name << D.getCXXScopeSpec().getRange();
1433    } else if (!CurContext->Encloses(DC)) {
1434      // The qualifying scope doesn't enclose the original declaration.
1435      // Emit diagnostic based on current scope.
1436      SourceLocation L = D.getIdentifierLoc();
1437      SourceRange R = D.getCXXScopeSpec().getRange();
1438      if (isa<FunctionDecl>(CurContext))
1439        Diag(L, diag::err_invalid_declarator_in_function) << Name << R;
1440      else
1441        Diag(L, diag::err_invalid_declarator_scope)
1442          << Name << cast<NamedDecl>(DC) << R;
1443      D.setInvalidType();
1444    }
1445  }
1446
1447  if (PrevDecl && PrevDecl->isTemplateParameter()) {
1448    // Maybe we will complain about the shadowed template parameter.
1449    if (!D.isInvalidType())
1450      if (DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl))
1451        D.setInvalidType();
1452
1453    // Just pretend that we didn't see the previous declaration.
1454    PrevDecl = 0;
1455  }
1456
1457  // In C++, the previous declaration we find might be a tag type
1458  // (class or enum). In this case, the new declaration will hide the
1459  // tag type. Note that this does does not apply if we're declaring a
1460  // typedef (C++ [dcl.typedef]p4).
1461  if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag &&
1462      D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef)
1463    PrevDecl = 0;
1464
1465  bool Redeclaration = false;
1466  if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
1467    New = ActOnTypedefDeclarator(S, D, DC, R, PrevDecl, Redeclaration);
1468  } else if (R->isFunctionType()) {
1469    New = ActOnFunctionDeclarator(S, D, DC, R, PrevDecl,
1470                                  IsFunctionDefinition, Redeclaration);
1471  } else {
1472    New = ActOnVariableDeclarator(S, D, DC, R, PrevDecl, Redeclaration);
1473  }
1474
1475  if (New == 0)
1476    return DeclPtrTy();
1477
1478  // If this has an identifier and is not an invalid redeclaration,
1479  // add it to the scope stack.
1480  if (Name && !(Redeclaration && New->isInvalidDecl()))
1481    PushOnScopeChains(New, S);
1482
1483  return DeclPtrTy::make(New);
1484}
1485
1486/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array
1487/// types into constant array types in certain situations which would otherwise
1488/// be errors (for GCC compatibility).
1489static QualType TryToFixInvalidVariablyModifiedType(QualType T,
1490                                                    ASTContext &Context,
1491                                                    bool &SizeIsNegative) {
1492  // This method tries to turn a variable array into a constant
1493  // array even when the size isn't an ICE.  This is necessary
1494  // for compatibility with code that depends on gcc's buggy
1495  // constant expression folding, like struct {char x[(int)(char*)2];}
1496  SizeIsNegative = false;
1497
1498  if (const PointerType* PTy = dyn_cast<PointerType>(T)) {
1499    QualType Pointee = PTy->getPointeeType();
1500    QualType FixedType =
1501        TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative);
1502    if (FixedType.isNull()) return FixedType;
1503    FixedType = Context.getPointerType(FixedType);
1504    FixedType.setCVRQualifiers(T.getCVRQualifiers());
1505    return FixedType;
1506  }
1507
1508  const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T);
1509  if (!VLATy)
1510    return QualType();
1511  // FIXME: We should probably handle this case
1512  if (VLATy->getElementType()->isVariablyModifiedType())
1513    return QualType();
1514
1515  Expr::EvalResult EvalResult;
1516  if (!VLATy->getSizeExpr() ||
1517      !VLATy->getSizeExpr()->Evaluate(EvalResult, Context) ||
1518      !EvalResult.Val.isInt())
1519    return QualType();
1520
1521  llvm::APSInt &Res = EvalResult.Val.getInt();
1522  if (Res >= llvm::APSInt(Res.getBitWidth(), Res.isUnsigned()))
1523    return Context.getConstantArrayType(VLATy->getElementType(),
1524                                        Res, ArrayType::Normal, 0);
1525
1526  SizeIsNegative = true;
1527  return QualType();
1528}
1529
1530/// \brief Register the given locally-scoped external C declaration so
1531/// that it can be found later for redeclarations
1532void
1533Sema::RegisterLocallyScopedExternCDecl(NamedDecl *ND, NamedDecl *PrevDecl,
1534                                       Scope *S) {
1535  assert(ND->getLexicalDeclContext()->isFunctionOrMethod() &&
1536         "Decl is not a locally-scoped decl!");
1537  // Note that we have a locally-scoped external with this name.
1538  LocallyScopedExternalDecls[ND->getDeclName()] = ND;
1539
1540  if (!PrevDecl)
1541    return;
1542
1543  // If there was a previous declaration of this variable, it may be
1544  // in our identifier chain. Update the identifier chain with the new
1545  // declaration.
1546  if (S && IdResolver.ReplaceDecl(PrevDecl, ND)) {
1547    // The previous declaration was found on the identifer resolver
1548    // chain, so remove it from its scope.
1549    while (S && !S->isDeclScope(DeclPtrTy::make(PrevDecl)))
1550      S = S->getParent();
1551
1552    if (S)
1553      S->RemoveDecl(DeclPtrTy::make(PrevDecl));
1554  }
1555}
1556
1557/// \brief Diagnose function specifiers on a declaration of an identifier that
1558/// does not identify a function.
1559void Sema::DiagnoseFunctionSpecifiers(Declarator& D) {
1560  // FIXME: We should probably indicate the identifier in question to avoid
1561  // confusion for constructs like "inline int a(), b;"
1562  if (D.getDeclSpec().isInlineSpecified())
1563    Diag(D.getDeclSpec().getInlineSpecLoc(),
1564         diag::err_inline_non_function);
1565
1566  if (D.getDeclSpec().isVirtualSpecified())
1567    Diag(D.getDeclSpec().getVirtualSpecLoc(),
1568         diag::err_virtual_non_function);
1569
1570  if (D.getDeclSpec().isExplicitSpecified())
1571    Diag(D.getDeclSpec().getExplicitSpecLoc(),
1572         diag::err_explicit_non_function);
1573}
1574
1575NamedDecl*
1576Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC,
1577                             QualType R, Decl* PrevDecl, bool &Redeclaration) {
1578  // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1).
1579  if (D.getCXXScopeSpec().isSet()) {
1580    Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator)
1581      << D.getCXXScopeSpec().getRange();
1582    D.setInvalidType();
1583    // Pretend we didn't see the scope specifier.
1584    DC = 0;
1585  }
1586
1587  if (getLangOptions().CPlusPlus) {
1588    // Check that there are no default arguments (C++ only).
1589    CheckExtraCXXDefaultArguments(D);
1590  }
1591
1592  DiagnoseFunctionSpecifiers(D);
1593
1594  if (D.getDeclSpec().isThreadSpecified())
1595    Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread);
1596
1597  TypedefDecl *NewTD = ParseTypedefDecl(S, D, R);
1598  if (!NewTD) return 0;
1599
1600  if (D.isInvalidType())
1601    NewTD->setInvalidDecl();
1602
1603  // Handle attributes prior to checking for duplicates in MergeVarDecl
1604  ProcessDeclAttributes(NewTD, D);
1605  // Merge the decl with the existing one if appropriate. If the decl is
1606  // in an outer scope, it isn't the same thing.
1607  if (PrevDecl && isDeclInScope(PrevDecl, DC, S)) {
1608    Redeclaration = true;
1609    MergeTypeDefDecl(NewTD, PrevDecl);
1610  }
1611
1612  // C99 6.7.7p2: If a typedef name specifies a variably modified type
1613  // then it shall have block scope.
1614  QualType T = NewTD->getUnderlyingType();
1615  if (T->isVariablyModifiedType()) {
1616    CurFunctionNeedsScopeChecking = true;
1617
1618    if (S->getFnParent() == 0) {
1619      bool SizeIsNegative;
1620      QualType FixedTy =
1621          TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative);
1622      if (!FixedTy.isNull()) {
1623        Diag(D.getIdentifierLoc(), diag::warn_illegal_constant_array_size);
1624        NewTD->setUnderlyingType(FixedTy);
1625      } else {
1626        if (SizeIsNegative)
1627          Diag(D.getIdentifierLoc(), diag::err_typecheck_negative_array_size);
1628        else if (T->isVariableArrayType())
1629          Diag(D.getIdentifierLoc(), diag::err_vla_decl_in_file_scope);
1630        else
1631          Diag(D.getIdentifierLoc(), diag::err_vm_decl_in_file_scope);
1632        NewTD->setInvalidDecl();
1633      }
1634    }
1635  }
1636  return NewTD;
1637}
1638
1639/// \brief Determines whether the given declaration is an out-of-scope
1640/// previous declaration.
1641///
1642/// This routine should be invoked when name lookup has found a
1643/// previous declaration (PrevDecl) that is not in the scope where a
1644/// new declaration by the same name is being introduced. If the new
1645/// declaration occurs in a local scope, previous declarations with
1646/// linkage may still be considered previous declarations (C99
1647/// 6.2.2p4-5, C++ [basic.link]p6).
1648///
1649/// \param PrevDecl the previous declaration found by name
1650/// lookup
1651///
1652/// \param DC the context in which the new declaration is being
1653/// declared.
1654///
1655/// \returns true if PrevDecl is an out-of-scope previous declaration
1656/// for a new delcaration with the same name.
1657static bool
1658isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC,
1659                                ASTContext &Context) {
1660  if (!PrevDecl)
1661    return 0;
1662
1663  // FIXME: PrevDecl could be an OverloadedFunctionDecl, in which
1664  // case we need to check each of the overloaded functions.
1665  if (!PrevDecl->hasLinkage())
1666    return false;
1667
1668  if (Context.getLangOptions().CPlusPlus) {
1669    // C++ [basic.link]p6:
1670    //   If there is a visible declaration of an entity with linkage
1671    //   having the same name and type, ignoring entities declared
1672    //   outside the innermost enclosing namespace scope, the block
1673    //   scope declaration declares that same entity and receives the
1674    //   linkage of the previous declaration.
1675    DeclContext *OuterContext = DC->getLookupContext();
1676    if (!OuterContext->isFunctionOrMethod())
1677      // This rule only applies to block-scope declarations.
1678      return false;
1679    else {
1680      DeclContext *PrevOuterContext = PrevDecl->getDeclContext();
1681      if (PrevOuterContext->isRecord())
1682        // We found a member function: ignore it.
1683        return false;
1684      else {
1685        // Find the innermost enclosing namespace for the new and
1686        // previous declarations.
1687        while (!OuterContext->isFileContext())
1688          OuterContext = OuterContext->getParent();
1689        while (!PrevOuterContext->isFileContext())
1690          PrevOuterContext = PrevOuterContext->getParent();
1691
1692        // The previous declaration is in a different namespace, so it
1693        // isn't the same function.
1694        if (OuterContext->getPrimaryContext() !=
1695            PrevOuterContext->getPrimaryContext())
1696          return false;
1697      }
1698    }
1699  }
1700
1701  return true;
1702}
1703
1704NamedDecl*
1705Sema::ActOnVariableDeclarator(Scope* S, Declarator& D, DeclContext* DC,
1706                              QualType R,NamedDecl* PrevDecl,
1707                              bool &Redeclaration) {
1708  DeclarationName Name = GetNameForDeclarator(D);
1709
1710  // Check that there are no default arguments (C++ only).
1711  if (getLangOptions().CPlusPlus)
1712    CheckExtraCXXDefaultArguments(D);
1713
1714  VarDecl *NewVD;
1715  VarDecl::StorageClass SC;
1716  switch (D.getDeclSpec().getStorageClassSpec()) {
1717  default: assert(0 && "Unknown storage class!");
1718  case DeclSpec::SCS_unspecified:    SC = VarDecl::None; break;
1719  case DeclSpec::SCS_extern:         SC = VarDecl::Extern; break;
1720  case DeclSpec::SCS_static:         SC = VarDecl::Static; break;
1721  case DeclSpec::SCS_auto:           SC = VarDecl::Auto; break;
1722  case DeclSpec::SCS_register:       SC = VarDecl::Register; break;
1723  case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break;
1724  case DeclSpec::SCS_mutable:
1725    // mutable can only appear on non-static class members, so it's always
1726    // an error here
1727    Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember);
1728    D.setInvalidType();
1729    SC = VarDecl::None;
1730    break;
1731  }
1732
1733  IdentifierInfo *II = Name.getAsIdentifierInfo();
1734  if (!II) {
1735    Diag(D.getIdentifierLoc(), diag::err_bad_variable_name)
1736      << Name.getAsString();
1737    return 0;
1738  }
1739
1740  DiagnoseFunctionSpecifiers(D);
1741
1742  if (!DC->isRecord() && S->getFnParent() == 0) {
1743    // C99 6.9p2: The storage-class specifiers auto and register shall not
1744    // appear in the declaration specifiers in an external declaration.
1745    if (SC == VarDecl::Auto || SC == VarDecl::Register) {
1746      Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope);
1747      D.setInvalidType();
1748    }
1749  }
1750  if (DC->isRecord() && !CurContext->isRecord()) {
1751    // This is an out-of-line definition of a static data member.
1752    if (SC == VarDecl::Static) {
1753      Diag(D.getDeclSpec().getStorageClassSpecLoc(),
1754           diag::err_static_out_of_line)
1755        << CodeModificationHint::CreateRemoval(
1756                       SourceRange(D.getDeclSpec().getStorageClassSpecLoc()));
1757    } else if (SC == VarDecl::None)
1758      SC = VarDecl::Static;
1759  }
1760
1761  // The variable can not
1762  NewVD = VarDecl::Create(Context, DC, D.getIdentifierLoc(),
1763                          II, R, SC,
1764                          // FIXME: Move to DeclGroup...
1765                          D.getDeclSpec().getSourceRange().getBegin());
1766
1767  if (D.isInvalidType())
1768    NewVD->setInvalidDecl();
1769
1770  if (D.getDeclSpec().isThreadSpecified()) {
1771    if (NewVD->hasLocalStorage())
1772      Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_non_global);
1773    else if (!Context.Target.isTLSSupported())
1774      Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_thread_unsupported);
1775    else
1776      NewVD->setThreadSpecified(true);
1777  }
1778
1779  // Set the lexical context. If the declarator has a C++ scope specifier, the
1780  // lexical context will be different from the semantic context.
1781  NewVD->setLexicalDeclContext(CurContext);
1782
1783  // Handle attributes prior to checking for duplicates in MergeVarDecl
1784  ProcessDeclAttributes(NewVD, D);
1785
1786  // Handle GNU asm-label extension (encoded as an attribute).
1787  if (Expr *E = (Expr*) D.getAsmLabel()) {
1788    // The parser guarantees this is a string.
1789    StringLiteral *SE = cast<StringLiteral>(E);
1790    NewVD->addAttr(::new (Context) AsmLabelAttr(std::string(SE->getStrData(),
1791                                                        SE->getByteLength())));
1792  }
1793
1794  // If name lookup finds a previous declaration that is not in the
1795  // same scope as the new declaration, this may still be an
1796  // acceptable redeclaration.
1797  if (PrevDecl && !isDeclInScope(PrevDecl, DC, S) &&
1798      !(NewVD->hasLinkage() &&
1799        isOutOfScopePreviousDeclaration(PrevDecl, DC, Context)))
1800    PrevDecl = 0;
1801
1802  // Merge the decl with the existing one if appropriate.
1803  if (PrevDecl) {
1804    if (isa<FieldDecl>(PrevDecl) && D.getCXXScopeSpec().isSet()) {
1805      // The user tried to define a non-static data member
1806      // out-of-line (C++ [dcl.meaning]p1).
1807      Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line)
1808        << D.getCXXScopeSpec().getRange();
1809      PrevDecl = 0;
1810      NewVD->setInvalidDecl();
1811    }
1812  } else if (D.getCXXScopeSpec().isSet()) {
1813    // No previous declaration in the qualifying scope.
1814    Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member)
1815      << Name << D.getCXXScopeSpec().getRange();
1816    NewVD->setInvalidDecl();
1817  }
1818
1819  CheckVariableDeclaration(NewVD, PrevDecl, Redeclaration);
1820
1821  // If this is a locally-scoped extern C variable, update the map of
1822  // such variables.
1823  if (CurContext->isFunctionOrMethod() && NewVD->isExternC(Context) &&
1824      !NewVD->isInvalidDecl())
1825    RegisterLocallyScopedExternCDecl(NewVD, PrevDecl, S);
1826
1827  return NewVD;
1828}
1829
1830/// \brief Perform semantic checking on a newly-created variable
1831/// declaration.
1832///
1833/// This routine performs all of the type-checking required for a
1834/// variable declaration once it has been built. It is used both to
1835/// check variables after they have been parsed and their declarators
1836/// have been translated into a declaration, and to check variables
1837/// that have been instantiated from a template.
1838///
1839/// Sets NewVD->isInvalidDecl() if an error was encountered.
1840void Sema::CheckVariableDeclaration(VarDecl *NewVD, NamedDecl *PrevDecl,
1841                                    bool &Redeclaration) {
1842  // If the decl is already known invalid, don't check it.
1843  if (NewVD->isInvalidDecl())
1844    return;
1845
1846  QualType T = NewVD->getType();
1847
1848  if (T->isObjCInterfaceType()) {
1849    Diag(NewVD->getLocation(), diag::err_statically_allocated_object);
1850    return NewVD->setInvalidDecl();
1851  }
1852
1853  // The variable can not have an abstract class type.
1854  if (RequireNonAbstractType(NewVD->getLocation(), T,
1855                             diag::err_abstract_type_in_decl,
1856                             AbstractVariableType))
1857    return NewVD->setInvalidDecl();
1858
1859  // Emit an error if an address space was applied to decl with local storage.
1860  // This includes arrays of objects with address space qualifiers, but not
1861  // automatic variables that point to other address spaces.
1862  // ISO/IEC TR 18037 S5.1.2
1863  if (NewVD->hasLocalStorage() && (T.getAddressSpace() != 0)) {
1864    Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl);
1865    return NewVD->setInvalidDecl();
1866  }
1867
1868  if (NewVD->hasLocalStorage() && T.isObjCGCWeak()
1869      && !NewVD->hasAttr<BlocksAttr>())
1870    Diag(NewVD->getLocation(), diag::warn_attribute_weak_on_local);
1871
1872  bool isVM = T->isVariablyModifiedType();
1873  if (isVM || NewVD->hasAttr<CleanupAttr>())
1874    CurFunctionNeedsScopeChecking = true;
1875
1876  if ((isVM && NewVD->hasLinkage()) ||
1877      (T->isVariableArrayType() && NewVD->hasGlobalStorage())) {
1878    bool SizeIsNegative;
1879    QualType FixedTy =
1880        TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative);
1881
1882    if (FixedTy.isNull() && T->isVariableArrayType()) {
1883      const VariableArrayType *VAT = Context.getAsVariableArrayType(T);
1884      // FIXME: This won't give the correct result for
1885      // int a[10][n];
1886      SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange();
1887
1888      if (NewVD->isFileVarDecl())
1889        Diag(NewVD->getLocation(), diag::err_vla_decl_in_file_scope)
1890        << SizeRange;
1891      else if (NewVD->getStorageClass() == VarDecl::Static)
1892        Diag(NewVD->getLocation(), diag::err_vla_decl_has_static_storage)
1893        << SizeRange;
1894      else
1895        Diag(NewVD->getLocation(), diag::err_vla_decl_has_extern_linkage)
1896        << SizeRange;
1897      return NewVD->setInvalidDecl();
1898    }
1899
1900    if (FixedTy.isNull()) {
1901      if (NewVD->isFileVarDecl())
1902        Diag(NewVD->getLocation(), diag::err_vm_decl_in_file_scope);
1903      else
1904        Diag(NewVD->getLocation(), diag::err_vm_decl_has_extern_linkage);
1905      return NewVD->setInvalidDecl();
1906    }
1907
1908    Diag(NewVD->getLocation(), diag::warn_illegal_constant_array_size);
1909    NewVD->setType(FixedTy);
1910  }
1911
1912  if (!PrevDecl && NewVD->isExternC(Context)) {
1913    // Since we did not find anything by this name and we're declaring
1914    // an extern "C" variable, look for a non-visible extern "C"
1915    // declaration with the same name.
1916    llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos
1917      = LocallyScopedExternalDecls.find(NewVD->getDeclName());
1918    if (Pos != LocallyScopedExternalDecls.end())
1919      PrevDecl = Pos->second;
1920  }
1921
1922  if (T->isVoidType() && !NewVD->hasExternalStorage()) {
1923    Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type)
1924      << T;
1925    return NewVD->setInvalidDecl();
1926  }
1927
1928  if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) {
1929    Diag(NewVD->getLocation(), diag::err_block_on_nonlocal);
1930    return NewVD->setInvalidDecl();
1931  }
1932
1933  if (isVM && NewVD->hasAttr<BlocksAttr>()) {
1934    Diag(NewVD->getLocation(), diag::err_block_on_vm);
1935    return NewVD->setInvalidDecl();
1936  }
1937
1938  if (PrevDecl) {
1939    Redeclaration = true;
1940    MergeVarDecl(NewVD, PrevDecl);
1941  }
1942}
1943
1944NamedDecl*
1945Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC,
1946                              QualType R, NamedDecl* PrevDecl,
1947                              bool IsFunctionDefinition, bool &Redeclaration) {
1948  assert(R.getTypePtr()->isFunctionType());
1949
1950  DeclarationName Name = GetNameForDeclarator(D);
1951  FunctionDecl::StorageClass SC = FunctionDecl::None;
1952  switch (D.getDeclSpec().getStorageClassSpec()) {
1953  default: assert(0 && "Unknown storage class!");
1954  case DeclSpec::SCS_auto:
1955  case DeclSpec::SCS_register:
1956  case DeclSpec::SCS_mutable:
1957    Diag(D.getDeclSpec().getStorageClassSpecLoc(),
1958         diag::err_typecheck_sclass_func);
1959    D.setInvalidType();
1960    break;
1961  case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break;
1962  case DeclSpec::SCS_extern:      SC = FunctionDecl::Extern; break;
1963  case DeclSpec::SCS_static: {
1964    if (CurContext->getLookupContext()->isFunctionOrMethod()) {
1965      // C99 6.7.1p5:
1966      //   The declaration of an identifier for a function that has
1967      //   block scope shall have no explicit storage-class specifier
1968      //   other than extern
1969      // See also (C++ [dcl.stc]p4).
1970      Diag(D.getDeclSpec().getStorageClassSpecLoc(),
1971           diag::err_static_block_func);
1972      SC = FunctionDecl::None;
1973    } else
1974      SC = FunctionDecl::Static;
1975    break;
1976  }
1977  case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break;
1978  }
1979
1980  if (D.getDeclSpec().isThreadSpecified())
1981    Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread);
1982
1983  bool isInline = D.getDeclSpec().isInlineSpecified();
1984  bool isVirtual = D.getDeclSpec().isVirtualSpecified();
1985  bool isExplicit = D.getDeclSpec().isExplicitSpecified();
1986
1987  // Check that the return type is not an abstract class type.
1988  // For record types, this is done by the AbstractClassUsageDiagnoser once
1989  // the class has been completely parsed.
1990  if (!DC->isRecord() &&
1991      RequireNonAbstractType(D.getIdentifierLoc(),
1992                             R->getAsFunctionType()->getResultType(),
1993                             diag::err_abstract_type_in_decl,
1994                             AbstractReturnType))
1995    D.setInvalidType();
1996
1997  // Do not allow returning a objc interface by-value.
1998  if (R->getAsFunctionType()->getResultType()->isObjCInterfaceType()) {
1999    Diag(D.getIdentifierLoc(),
2000         diag::err_object_cannot_be_passed_returned_by_value) << 0
2001      << R->getAsFunctionType()->getResultType();
2002    D.setInvalidType();
2003  }
2004
2005  bool isVirtualOkay = false;
2006  FunctionDecl *NewFD;
2007  if (D.getKind() == Declarator::DK_Constructor) {
2008    // This is a C++ constructor declaration.
2009    assert(DC->isRecord() &&
2010           "Constructors can only be declared in a member context");
2011
2012    R = CheckConstructorDeclarator(D, R, SC);
2013
2014    // Create the new declaration
2015    NewFD = CXXConstructorDecl::Create(Context,
2016                                       cast<CXXRecordDecl>(DC),
2017                                       D.getIdentifierLoc(), Name, R,
2018                                       isExplicit, isInline,
2019                                       /*isImplicitlyDeclared=*/false);
2020  } else if (D.getKind() == Declarator::DK_Destructor) {
2021    // This is a C++ destructor declaration.
2022    if (DC->isRecord()) {
2023      R = CheckDestructorDeclarator(D, SC);
2024
2025      NewFD = CXXDestructorDecl::Create(Context,
2026                                        cast<CXXRecordDecl>(DC),
2027                                        D.getIdentifierLoc(), Name, R,
2028                                        isInline,
2029                                        /*isImplicitlyDeclared=*/false);
2030
2031      isVirtualOkay = true;
2032    } else {
2033      Diag(D.getIdentifierLoc(), diag::err_destructor_not_member);
2034
2035      // Create a FunctionDecl to satisfy the function definition parsing
2036      // code path.
2037      NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(),
2038                                   Name, R, SC, isInline,
2039                                   /*hasPrototype=*/true,
2040                                   // FIXME: Move to DeclGroup...
2041                                   D.getDeclSpec().getSourceRange().getBegin());
2042      D.setInvalidType();
2043    }
2044  } else if (D.getKind() == Declarator::DK_Conversion) {
2045    if (!DC->isRecord()) {
2046      Diag(D.getIdentifierLoc(),
2047           diag::err_conv_function_not_member);
2048      return 0;
2049    }
2050
2051    CheckConversionDeclarator(D, R, SC);
2052    NewFD = CXXConversionDecl::Create(Context, cast<CXXRecordDecl>(DC),
2053                                      D.getIdentifierLoc(), Name, R,
2054                                      isInline, isExplicit);
2055
2056    isVirtualOkay = true;
2057  } else if (DC->isRecord()) {
2058    // If the of the function is the same as the name of the record, then this
2059    // must be an invalid constructor that has a return type.
2060    // (The parser checks for a return type and makes the declarator a
2061    // constructor if it has no return type).
2062    // must have an invalid constructor that has a return type
2063    if (Name.getAsIdentifierInfo() == cast<CXXRecordDecl>(DC)->getIdentifier()){
2064      Diag(D.getIdentifierLoc(), diag::err_constructor_return_type)
2065        << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
2066        << SourceRange(D.getIdentifierLoc());
2067      return 0;
2068    }
2069
2070    // This is a C++ method declaration.
2071    NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC),
2072                                  D.getIdentifierLoc(), Name, R,
2073                                  (SC == FunctionDecl::Static), isInline);
2074
2075    isVirtualOkay = (SC != FunctionDecl::Static);
2076  } else {
2077    // Determine whether the function was written with a
2078    // prototype. This true when:
2079    //   - we're in C++ (where every function has a prototype),
2080    //   - there is a prototype in the declarator, or
2081    //   - the type R of the function is some kind of typedef or other reference
2082    //     to a type name (which eventually refers to a function type).
2083    bool HasPrototype =
2084       getLangOptions().CPlusPlus ||
2085       (D.getNumTypeObjects() && D.getTypeObject(0).Fun.hasPrototype) ||
2086       (!isa<FunctionType>(R.getTypePtr()) && R->isFunctionProtoType());
2087
2088    NewFD = FunctionDecl::Create(Context, DC,
2089                                 D.getIdentifierLoc(),
2090                                 Name, R, SC, isInline, HasPrototype,
2091                                 // FIXME: Move to DeclGroup...
2092                                 D.getDeclSpec().getSourceRange().getBegin());
2093  }
2094
2095  if (D.isInvalidType())
2096    NewFD->setInvalidDecl();
2097
2098  // Set the lexical context. If the declarator has a C++
2099  // scope specifier, the lexical context will be different
2100  // from the semantic context.
2101  NewFD->setLexicalDeclContext(CurContext);
2102
2103  // C++ [dcl.fct.spec]p5:
2104  //   The virtual specifier shall only be used in declarations of
2105  //   nonstatic class member functions that appear within a
2106  //   member-specification of a class declaration; see 10.3.
2107  //
2108  // FIXME: Checking the 'virtual' specifier is not sufficient. A
2109  // function is also virtual if it overrides an already virtual
2110  // function. This is important to do here because it's part of the
2111  // declaration.
2112  if (isVirtual && !NewFD->isInvalidDecl()) {
2113    if (!isVirtualOkay) {
2114       Diag(D.getDeclSpec().getVirtualSpecLoc(),
2115           diag::err_virtual_non_function);
2116    } else if (!CurContext->isRecord()) {
2117      // 'virtual' was specified outside of the class.
2118      Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_virtual_out_of_class)
2119        << CodeModificationHint::CreateRemoval(
2120                             SourceRange(D.getDeclSpec().getVirtualSpecLoc()));
2121    } else {
2122      // Okay: Add virtual to the method.
2123      cast<CXXMethodDecl>(NewFD)->setVirtual();
2124      CXXRecordDecl *CurClass = cast<CXXRecordDecl>(DC);
2125      CurClass->setAggregate(false);
2126      CurClass->setPOD(false);
2127      CurClass->setPolymorphic(true);
2128      CurClass->setHasTrivialConstructor(false);
2129    }
2130  }
2131
2132  if (SC == FunctionDecl::Static && isa<CXXMethodDecl>(NewFD) &&
2133      !CurContext->isRecord()) {
2134    // C++ [class.static]p1:
2135    //   A data or function member of a class may be declared static
2136    //   in a class definition, in which case it is a static member of
2137    //   the class.
2138
2139    // Complain about the 'static' specifier if it's on an out-of-line
2140    // member function definition.
2141    Diag(D.getDeclSpec().getStorageClassSpecLoc(),
2142         diag::err_static_out_of_line)
2143      << CodeModificationHint::CreateRemoval(
2144                      SourceRange(D.getDeclSpec().getStorageClassSpecLoc()));
2145  }
2146
2147  // Handle GNU asm-label extension (encoded as an attribute).
2148  if (Expr *E = (Expr*) D.getAsmLabel()) {
2149    // The parser guarantees this is a string.
2150    StringLiteral *SE = cast<StringLiteral>(E);
2151    NewFD->addAttr(::new (Context) AsmLabelAttr(std::string(SE->getStrData(),
2152                                                        SE->getByteLength())));
2153  }
2154
2155  // Copy the parameter declarations from the declarator D to the function
2156  // declaration NewFD, if they are available.  First scavenge them into Params.
2157  llvm::SmallVector<ParmVarDecl*, 16> Params;
2158  if (D.getNumTypeObjects() > 0) {
2159    DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
2160
2161    // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs
2162    // function that takes no arguments, not a function that takes a
2163    // single void argument.
2164    // We let through "const void" here because Sema::GetTypeForDeclarator
2165    // already checks for that case.
2166    if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 &&
2167        FTI.ArgInfo[0].Param &&
2168        FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType()->isVoidType()) {
2169      // Empty arg list, don't push any params.
2170      ParmVarDecl *Param = FTI.ArgInfo[0].Param.getAs<ParmVarDecl>();
2171
2172      // In C++, the empty parameter-type-list must be spelled "void"; a
2173      // typedef of void is not permitted.
2174      if (getLangOptions().CPlusPlus &&
2175          Param->getType().getUnqualifiedType() != Context.VoidTy)
2176        Diag(Param->getLocation(), diag::err_param_typedef_of_void);
2177      // FIXME: Leaks decl?
2178    } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) {
2179      for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i)
2180        Params.push_back(FTI.ArgInfo[i].Param.getAs<ParmVarDecl>());
2181    }
2182
2183  } else if (const FunctionProtoType *FT = R->getAsFunctionProtoType()) {
2184    // When we're declaring a function with a typedef, typeof, etc as in the
2185    // following example, we'll need to synthesize (unnamed)
2186    // parameters for use in the declaration.
2187    //
2188    // @code
2189    // typedef void fn(int);
2190    // fn f;
2191    // @endcode
2192
2193    // Synthesize a parameter for each argument type.
2194    for (FunctionProtoType::arg_type_iterator AI = FT->arg_type_begin(),
2195         AE = FT->arg_type_end(); AI != AE; ++AI) {
2196      ParmVarDecl *Param = ParmVarDecl::Create(Context, DC,
2197                                               SourceLocation(), 0,
2198                                               *AI, VarDecl::None, 0);
2199      Param->setImplicit();
2200      Params.push_back(Param);
2201    }
2202  } else {
2203    assert(R->isFunctionNoProtoType() && NewFD->getNumParams() == 0 &&
2204           "Should not need args for typedef of non-prototype fn");
2205  }
2206  // Finally, we know we have the right number of parameters, install them.
2207  NewFD->setParams(Context, &Params[0], Params.size());
2208
2209
2210
2211  // If name lookup finds a previous declaration that is not in the
2212  // same scope as the new declaration, this may still be an
2213  // acceptable redeclaration.
2214  if (PrevDecl && !isDeclInScope(PrevDecl, DC, S) &&
2215      !(NewFD->hasLinkage() &&
2216        isOutOfScopePreviousDeclaration(PrevDecl, DC, Context)))
2217    PrevDecl = 0;
2218
2219  // Perform semantic checking on the function declaration.
2220  bool OverloadableAttrRequired = false; // FIXME: HACK!
2221  CheckFunctionDeclaration(NewFD, PrevDecl, Redeclaration,
2222                           /*FIXME:*/OverloadableAttrRequired);
2223
2224  if (D.getCXXScopeSpec().isSet() && !NewFD->isInvalidDecl()) {
2225    // An out-of-line member function declaration must also be a
2226    // definition (C++ [dcl.meaning]p1).
2227    if (!IsFunctionDefinition) {
2228      Diag(NewFD->getLocation(), diag::err_out_of_line_declaration)
2229        << D.getCXXScopeSpec().getRange();
2230      NewFD->setInvalidDecl();
2231    } else if (!Redeclaration) {
2232      // The user tried to provide an out-of-line definition for a
2233      // function that is a member of a class or namespace, but there
2234      // was no such member function declared (C++ [class.mfct]p2,
2235      // C++ [namespace.memdef]p2). For example:
2236      //
2237      // class X {
2238      //   void f() const;
2239      // };
2240      //
2241      // void X::f() { } // ill-formed
2242      //
2243      // Complain about this problem, and attempt to suggest close
2244      // matches (e.g., those that differ only in cv-qualifiers and
2245      // whether the parameter types are references).
2246      Diag(D.getIdentifierLoc(), diag::err_member_def_does_not_match)
2247        << cast<NamedDecl>(DC) << D.getCXXScopeSpec().getRange();
2248      NewFD->setInvalidDecl();
2249
2250      LookupResult Prev = LookupQualifiedName(DC, Name, LookupOrdinaryName,
2251                                              true);
2252      assert(!Prev.isAmbiguous() &&
2253             "Cannot have an ambiguity in previous-declaration lookup");
2254      for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end();
2255           Func != FuncEnd; ++Func) {
2256        if (isa<FunctionDecl>(*Func) &&
2257            isNearlyMatchingFunction(Context, cast<FunctionDecl>(*Func), NewFD))
2258          Diag((*Func)->getLocation(), diag::note_member_def_close_match);
2259      }
2260
2261      PrevDecl = 0;
2262    }
2263  }
2264
2265  // Handle attributes. We need to have merged decls when handling attributes
2266  // (for example to check for conflicts, etc).
2267  // FIXME: This needs to happen before we merge declarations. Then,
2268  // let attribute merging cope with attribute conflicts.
2269  ProcessDeclAttributes(NewFD, D);
2270  AddKnownFunctionAttributes(NewFD);
2271
2272  if (OverloadableAttrRequired && !NewFD->getAttr<OverloadableAttr>()) {
2273    // If a function name is overloadable in C, then every function
2274    // with that name must be marked "overloadable".
2275    Diag(NewFD->getLocation(), diag::err_attribute_overloadable_missing)
2276      << Redeclaration << NewFD;
2277    if (PrevDecl)
2278      Diag(PrevDecl->getLocation(),
2279           diag::note_attribute_overloadable_prev_overload);
2280    NewFD->addAttr(::new (Context) OverloadableAttr());
2281  }
2282
2283  // If this is a locally-scoped extern C function, update the
2284  // map of such names.
2285  if (CurContext->isFunctionOrMethod() && NewFD->isExternC(Context)
2286      && !NewFD->isInvalidDecl())
2287    RegisterLocallyScopedExternCDecl(NewFD, PrevDecl, S);
2288
2289  return NewFD;
2290}
2291
2292/// \brief Perform semantic checking of a new function declaration.
2293///
2294/// Performs semantic analysis of the new function declaration
2295/// NewFD. This routine performs all semantic checking that does not
2296/// require the actual declarator involved in the declaration, and is
2297/// used both for the declaration of functions as they are parsed
2298/// (called via ActOnDeclarator) and for the declaration of functions
2299/// that have been instantiated via C++ template instantiation (called
2300/// via InstantiateDecl).
2301///
2302/// This sets NewFD->isInvalidDecl() to true if there was an error.
2303void Sema::CheckFunctionDeclaration(FunctionDecl *NewFD, NamedDecl *&PrevDecl,
2304                                    bool &Redeclaration,
2305                                    bool &OverloadableAttrRequired) {
2306  // If NewFD is already known erroneous, don't do any of this checking.
2307  if (NewFD->isInvalidDecl())
2308    return;
2309
2310  // Semantic checking for this function declaration (in isolation).
2311  if (getLangOptions().CPlusPlus) {
2312    // C++-specific checks.
2313    if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) {
2314      CheckConstructor(Constructor);
2315    } else if (isa<CXXDestructorDecl>(NewFD)) {
2316      CXXRecordDecl *Record = cast<CXXRecordDecl>(NewFD->getParent());
2317      Record->setUserDeclaredDestructor(true);
2318      // C++ [class]p4: A POD-struct is an aggregate class that has [...] no
2319      // user-defined destructor.
2320      Record->setPOD(false);
2321
2322      // C++ [class.dtor]p3: A destructor is trivial if it is an implicitly-
2323      // declared destructor.
2324      Record->setHasTrivialDestructor(false);
2325    } else if (CXXConversionDecl *Conversion
2326               = dyn_cast<CXXConversionDecl>(NewFD))
2327      ActOnConversionDeclarator(Conversion);
2328
2329    // Extra checking for C++ overloaded operators (C++ [over.oper]).
2330    if (NewFD->isOverloadedOperator() &&
2331        CheckOverloadedOperatorDeclaration(NewFD))
2332      return NewFD->setInvalidDecl();
2333  }
2334
2335  // C99 6.7.4p6:
2336  //   [... ] For a function with external linkage, the following
2337  //   restrictions apply: [...] If all of the file scope declarations
2338  //   for a function in a translation unit include the inline
2339  //   function specifier without extern, then the definition in that
2340  //   translation unit is an inline definition. An inline definition
2341  //   does not provide an external definition for the function, and
2342  //   does not forbid an external definition in another translation
2343  //   unit.
2344  //
2345  // Here we determine whether this function, in isolation, would be a
2346  // C99 inline definition. MergeCompatibleFunctionDecls looks at
2347  // previous declarations.
2348  if (NewFD->isInline() && getLangOptions().C99 &&
2349      NewFD->getStorageClass() == FunctionDecl::None &&
2350      NewFD->getDeclContext()->getLookupContext()->isTranslationUnit())
2351    NewFD->setC99InlineDefinition(true);
2352
2353  // Check for a previous declaration of this name.
2354  if (!PrevDecl && NewFD->isExternC(Context)) {
2355    // Since we did not find anything by this name and we're declaring
2356    // an extern "C" function, look for a non-visible extern "C"
2357    // declaration with the same name.
2358    llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos
2359      = LocallyScopedExternalDecls.find(NewFD->getDeclName());
2360    if (Pos != LocallyScopedExternalDecls.end())
2361      PrevDecl = Pos->second;
2362  }
2363
2364  // Merge or overload the declaration with an existing declaration of
2365  // the same name, if appropriate.
2366  if (PrevDecl) {
2367    // Determine whether NewFD is an overload of PrevDecl or
2368    // a declaration that requires merging. If it's an overload,
2369    // there's no more work to do here; we'll just add the new
2370    // function to the scope.
2371    OverloadedFunctionDecl::function_iterator MatchedDecl;
2372
2373    if (!getLangOptions().CPlusPlus &&
2374        AllowOverloadingOfFunction(PrevDecl, Context)) {
2375      OverloadableAttrRequired = true;
2376
2377      // Functions marked "overloadable" must have a prototype (that
2378      // we can't get through declaration merging).
2379      if (!NewFD->getType()->getAsFunctionProtoType()) {
2380        Diag(NewFD->getLocation(), diag::err_attribute_overloadable_no_prototype)
2381          << NewFD;
2382        Redeclaration = true;
2383
2384        // Turn this into a variadic function with no parameters.
2385        QualType R = Context.getFunctionType(
2386                       NewFD->getType()->getAsFunctionType()->getResultType(),
2387                       0, 0, true, 0);
2388        NewFD->setType(R);
2389        return NewFD->setInvalidDecl();
2390      }
2391    }
2392
2393    if (PrevDecl &&
2394        (!AllowOverloadingOfFunction(PrevDecl, Context) ||
2395         !IsOverload(NewFD, PrevDecl, MatchedDecl))) {
2396      Redeclaration = true;
2397      Decl *OldDecl = PrevDecl;
2398
2399      // If PrevDecl was an overloaded function, extract the
2400      // FunctionDecl that matched.
2401      if (isa<OverloadedFunctionDecl>(PrevDecl))
2402        OldDecl = *MatchedDecl;
2403
2404      // NewFD and OldDecl represent declarations that need to be
2405      // merged.
2406      if (MergeFunctionDecl(NewFD, OldDecl))
2407        return NewFD->setInvalidDecl();
2408
2409      NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl));
2410    }
2411  }
2412
2413  // In C++, check default arguments now that we have merged decls. Unless
2414  // the lexical context is the class, because in this case this is done
2415  // during delayed parsing anyway.
2416  if (getLangOptions().CPlusPlus && !CurContext->isRecord())
2417    CheckCXXDefaultArguments(NewFD);
2418}
2419
2420bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) {
2421  // FIXME: Need strict checking.  In C89, we need to check for
2422  // any assignment, increment, decrement, function-calls, or
2423  // commas outside of a sizeof.  In C99, it's the same list,
2424  // except that the aforementioned are allowed in unevaluated
2425  // expressions.  Everything else falls under the
2426  // "may accept other forms of constant expressions" exception.
2427  // (We never end up here for C++, so the constant expression
2428  // rules there don't matter.)
2429  if (Init->isConstantInitializer(Context))
2430    return false;
2431  Diag(Init->getExprLoc(), diag::err_init_element_not_constant)
2432    << Init->getSourceRange();
2433  return true;
2434}
2435
2436void Sema::AddInitializerToDecl(DeclPtrTy dcl, ExprArg init) {
2437  AddInitializerToDecl(dcl, move(init), /*DirectInit=*/false);
2438}
2439
2440/// AddInitializerToDecl - Adds the initializer Init to the
2441/// declaration dcl. If DirectInit is true, this is C++ direct
2442/// initialization rather than copy initialization.
2443void Sema::AddInitializerToDecl(DeclPtrTy dcl, ExprArg init, bool DirectInit) {
2444  Decl *RealDecl = dcl.getAs<Decl>();
2445  // If there is no declaration, there was an error parsing it.  Just ignore
2446  // the initializer.
2447  if (RealDecl == 0)
2448    return;
2449
2450  if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(RealDecl)) {
2451    // With declarators parsed the way they are, the parser cannot
2452    // distinguish between a normal initializer and a pure-specifier.
2453    // Thus this grotesque test.
2454    IntegerLiteral *IL;
2455    Expr *Init = static_cast<Expr *>(init.get());
2456    if ((IL = dyn_cast<IntegerLiteral>(Init)) && IL->getValue() == 0 &&
2457        Context.getCanonicalType(IL->getType()) == Context.IntTy) {
2458      if (Method->isVirtual()) {
2459        Method->setPure();
2460
2461        // A class is abstract if at least one function is pure virtual.
2462        cast<CXXRecordDecl>(CurContext)->setAbstract(true);
2463      } else if (!Method->isInvalidDecl()) {
2464        Diag(Method->getLocation(), diag::err_non_virtual_pure)
2465          << Method->getDeclName() << Init->getSourceRange();
2466        Method->setInvalidDecl();
2467      }
2468    } else {
2469      Diag(Method->getLocation(), diag::err_member_function_initialization)
2470        << Method->getDeclName() << Init->getSourceRange();
2471      Method->setInvalidDecl();
2472    }
2473    return;
2474  }
2475
2476  VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl);
2477  if (!VDecl) {
2478    if (getLangOptions().CPlusPlus &&
2479        RealDecl->getLexicalDeclContext()->isRecord() &&
2480        isa<NamedDecl>(RealDecl))
2481      Diag(RealDecl->getLocation(), diag::err_member_initialization)
2482        << cast<NamedDecl>(RealDecl)->getDeclName();
2483    else
2484      Diag(RealDecl->getLocation(), diag::err_illegal_initializer);
2485    RealDecl->setInvalidDecl();
2486    return;
2487  }
2488
2489  if (!VDecl->getType()->isArrayType() &&
2490      RequireCompleteType(VDecl->getLocation(), VDecl->getType(),
2491                          diag::err_typecheck_decl_incomplete_type)) {
2492    RealDecl->setInvalidDecl();
2493    return;
2494  }
2495
2496  const VarDecl *Def = 0;
2497  if (VDecl->getDefinition(Def)) {
2498    Diag(VDecl->getLocation(), diag::err_redefinition)
2499      << VDecl->getDeclName();
2500    Diag(Def->getLocation(), diag::note_previous_definition);
2501    VDecl->setInvalidDecl();
2502    return;
2503  }
2504
2505  // Take ownership of the expression, now that we're sure we have somewhere
2506  // to put it.
2507  Expr *Init = init.takeAs<Expr>();
2508  assert(Init && "missing initializer");
2509
2510  // Get the decls type and save a reference for later, since
2511  // CheckInitializerTypes may change it.
2512  QualType DclT = VDecl->getType(), SavT = DclT;
2513  if (VDecl->isBlockVarDecl()) {
2514    if (VDecl->hasExternalStorage()) { // C99 6.7.8p5
2515      Diag(VDecl->getLocation(), diag::err_block_extern_cant_init);
2516      VDecl->setInvalidDecl();
2517    } else if (!VDecl->isInvalidDecl()) {
2518      if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(),
2519                                VDecl->getDeclName(), DirectInit))
2520        VDecl->setInvalidDecl();
2521
2522      // C++ 3.6.2p2, allow dynamic initialization of static initializers.
2523      // Don't check invalid declarations to avoid emitting useless diagnostics.
2524      if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) {
2525        if (VDecl->getStorageClass() == VarDecl::Static) // C99 6.7.8p4.
2526          CheckForConstantInitializer(Init, DclT);
2527      }
2528    }
2529  } else if (VDecl->isStaticDataMember() &&
2530             VDecl->getLexicalDeclContext()->isRecord()) {
2531    // This is an in-class initialization for a static data member, e.g.,
2532    //
2533    // struct S {
2534    //   static const int value = 17;
2535    // };
2536
2537    // Attach the initializer
2538    VDecl->setInit(Init);
2539
2540    // C++ [class.mem]p4:
2541    //   A member-declarator can contain a constant-initializer only
2542    //   if it declares a static member (9.4) of const integral or
2543    //   const enumeration type, see 9.4.2.
2544    QualType T = VDecl->getType();
2545    if (!T->isDependentType() &&
2546        (!Context.getCanonicalType(T).isConstQualified() ||
2547         !T->isIntegralType())) {
2548      Diag(VDecl->getLocation(), diag::err_member_initialization)
2549        << VDecl->getDeclName() << Init->getSourceRange();
2550      VDecl->setInvalidDecl();
2551    } else {
2552      // C++ [class.static.data]p4:
2553      //   If a static data member is of const integral or const
2554      //   enumeration type, its declaration in the class definition
2555      //   can specify a constant-initializer which shall be an
2556      //   integral constant expression (5.19).
2557      if (!Init->isTypeDependent() &&
2558          !Init->getType()->isIntegralType()) {
2559        // We have a non-dependent, non-integral or enumeration type.
2560        Diag(Init->getSourceRange().getBegin(),
2561             diag::err_in_class_initializer_non_integral_type)
2562          << Init->getType() << Init->getSourceRange();
2563        VDecl->setInvalidDecl();
2564      } else if (!Init->isTypeDependent() && !Init->isValueDependent()) {
2565        // Check whether the expression is a constant expression.
2566        llvm::APSInt Value;
2567        SourceLocation Loc;
2568        if (!Init->isIntegerConstantExpr(Value, Context, &Loc)) {
2569          Diag(Loc, diag::err_in_class_initializer_non_constant)
2570            << Init->getSourceRange();
2571          VDecl->setInvalidDecl();
2572        } else if (!VDecl->getType()->isDependentType())
2573          ImpCastExprToType(Init, VDecl->getType());
2574      }
2575    }
2576  } else if (VDecl->isFileVarDecl()) {
2577    if (VDecl->getStorageClass() == VarDecl::Extern)
2578      Diag(VDecl->getLocation(), diag::warn_extern_init);
2579    if (!VDecl->isInvalidDecl())
2580      if (CheckInitializerTypes(Init, DclT, VDecl->getLocation(),
2581                                VDecl->getDeclName(), DirectInit))
2582        VDecl->setInvalidDecl();
2583
2584    // C++ 3.6.2p2, allow dynamic initialization of static initializers.
2585    // Don't check invalid declarations to avoid emitting useless diagnostics.
2586    if (!getLangOptions().CPlusPlus && !VDecl->isInvalidDecl()) {
2587      // C99 6.7.8p4. All file scoped initializers need to be constant.
2588      CheckForConstantInitializer(Init, DclT);
2589    }
2590  }
2591  // If the type changed, it means we had an incomplete type that was
2592  // completed by the initializer. For example:
2593  //   int ary[] = { 1, 3, 5 };
2594  // "ary" transitions from a VariableArrayType to a ConstantArrayType.
2595  if (!VDecl->isInvalidDecl() && (DclT != SavT)) {
2596    VDecl->setType(DclT);
2597    Init->setType(DclT);
2598  }
2599
2600  // Attach the initializer to the decl.
2601  VDecl->setInit(Init);
2602
2603  // If the previous declaration of VDecl was a tentative definition,
2604  // remove it from the set of tentative definitions.
2605  if (VDecl->getPreviousDeclaration() &&
2606      VDecl->getPreviousDeclaration()->isTentativeDefinition(Context)) {
2607    llvm::DenseMap<DeclarationName, VarDecl *>::iterator Pos
2608      = TentativeDefinitions.find(VDecl->getDeclName());
2609    assert(Pos != TentativeDefinitions.end() &&
2610           "Unrecorded tentative definition?");
2611    TentativeDefinitions.erase(Pos);
2612  }
2613
2614  return;
2615}
2616
2617void Sema::ActOnUninitializedDecl(DeclPtrTy dcl) {
2618  Decl *RealDecl = dcl.getAs<Decl>();
2619
2620  // If there is no declaration, there was an error parsing it. Just ignore it.
2621  if (RealDecl == 0)
2622    return;
2623
2624  if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) {
2625    QualType Type = Var->getType();
2626
2627    // Record tentative definitions.
2628    if (Var->isTentativeDefinition(Context))
2629      TentativeDefinitions[Var->getDeclName()] = Var;
2630
2631    // C++ [dcl.init.ref]p3:
2632    //   The initializer can be omitted for a reference only in a
2633    //   parameter declaration (8.3.5), in the declaration of a
2634    //   function return type, in the declaration of a class member
2635    //   within its class declaration (9.2), and where the extern
2636    //   specifier is explicitly used.
2637    if (Type->isReferenceType() && !Var->hasExternalStorage()) {
2638      Diag(Var->getLocation(), diag::err_reference_var_requires_init)
2639        << Var->getDeclName()
2640        << SourceRange(Var->getLocation(), Var->getLocation());
2641      Var->setInvalidDecl();
2642      return;
2643    }
2644
2645    // C++ [dcl.init]p9:
2646    //
2647    //   If no initializer is specified for an object, and the object
2648    //   is of (possibly cv-qualified) non-POD class type (or array
2649    //   thereof), the object shall be default-initialized; if the
2650    //   object is of const-qualified type, the underlying class type
2651    //   shall have a user-declared default constructor.
2652    if (getLangOptions().CPlusPlus) {
2653      QualType InitType = Type;
2654      if (const ArrayType *Array = Context.getAsArrayType(Type))
2655        InitType = Array->getElementType();
2656      if (!Var->hasExternalStorage() && InitType->isRecordType()) {
2657        CXXRecordDecl *RD =
2658          cast<CXXRecordDecl>(InitType->getAsRecordType()->getDecl());
2659        CXXConstructorDecl *Constructor = 0;
2660        if (!RequireCompleteType(Var->getLocation(), InitType,
2661                                    diag::err_invalid_incomplete_type_use))
2662          Constructor
2663            = PerformInitializationByConstructor(InitType, 0, 0,
2664                                                 Var->getLocation(),
2665                                               SourceRange(Var->getLocation(),
2666                                                           Var->getLocation()),
2667                                                 Var->getDeclName(),
2668                                                 IK_Default);
2669        if (!Constructor)
2670          Var->setInvalidDecl();
2671        else if (!RD->hasTrivialConstructor())
2672          InitializeVarWithConstructor(Var, Constructor, InitType, 0, 0);
2673      }
2674    }
2675
2676#if 0
2677    // FIXME: Temporarily disabled because we are not properly parsing
2678    // linkage specifications on declarations, e.g.,
2679    //
2680    //   extern "C" const CGPoint CGPointerZero;
2681    //
2682    // C++ [dcl.init]p9:
2683    //
2684    //     If no initializer is specified for an object, and the
2685    //     object is of (possibly cv-qualified) non-POD class type (or
2686    //     array thereof), the object shall be default-initialized; if
2687    //     the object is of const-qualified type, the underlying class
2688    //     type shall have a user-declared default
2689    //     constructor. Otherwise, if no initializer is specified for
2690    //     an object, the object and its subobjects, if any, have an
2691    //     indeterminate initial value; if the object or any of its
2692    //     subobjects are of const-qualified type, the program is
2693    //     ill-formed.
2694    //
2695    // This isn't technically an error in C, so we don't diagnose it.
2696    //
2697    // FIXME: Actually perform the POD/user-defined default
2698    // constructor check.
2699    if (getLangOptions().CPlusPlus &&
2700        Context.getCanonicalType(Type).isConstQualified() &&
2701        !Var->hasExternalStorage())
2702      Diag(Var->getLocation(),  diag::err_const_var_requires_init)
2703        << Var->getName()
2704        << SourceRange(Var->getLocation(), Var->getLocation());
2705#endif
2706  }
2707}
2708
2709Sema::DeclGroupPtrTy Sema::FinalizeDeclaratorGroup(Scope *S, DeclPtrTy *Group,
2710                                                   unsigned NumDecls) {
2711  llvm::SmallVector<Decl*, 8> Decls;
2712
2713  for (unsigned i = 0; i != NumDecls; ++i)
2714    if (Decl *D = Group[i].getAs<Decl>())
2715      Decls.push_back(D);
2716
2717  // Perform semantic analysis that depends on having fully processed both
2718  // the declarator and initializer.
2719  for (unsigned i = 0, e = Decls.size(); i != e; ++i) {
2720    VarDecl *IDecl = dyn_cast<VarDecl>(Decls[i]);
2721    if (!IDecl)
2722      continue;
2723    QualType T = IDecl->getType();
2724
2725    // Block scope. C99 6.7p7: If an identifier for an object is declared with
2726    // no linkage (C99 6.2.2p6), the type for the object shall be complete...
2727    if (IDecl->isBlockVarDecl() && !IDecl->hasExternalStorage()) {
2728      if (!IDecl->isInvalidDecl() &&
2729          RequireCompleteType(IDecl->getLocation(), T,
2730                              diag::err_typecheck_decl_incomplete_type))
2731        IDecl->setInvalidDecl();
2732    }
2733    // File scope. C99 6.9.2p2: A declaration of an identifier for and
2734    // object that has file scope without an initializer, and without a
2735    // storage-class specifier or with the storage-class specifier "static",
2736    // constitutes a tentative definition. Note: A tentative definition with
2737    // external linkage is valid (C99 6.2.2p5).
2738    if (IDecl->isTentativeDefinition(Context)) {
2739      QualType CheckType = T;
2740      unsigned DiagID = diag::err_typecheck_decl_incomplete_type;
2741
2742      const IncompleteArrayType *ArrayT = Context.getAsIncompleteArrayType(T);
2743      if (ArrayT) {
2744        CheckType = ArrayT->getElementType();
2745        DiagID = diag::err_illegal_decl_array_incomplete_type;
2746      }
2747
2748      if (IDecl->isInvalidDecl()) {
2749        // Do nothing with invalid declarations
2750      } else if ((ArrayT || IDecl->getStorageClass() == VarDecl::Static) &&
2751                 RequireCompleteType(IDecl->getLocation(), CheckType, DiagID)) {
2752        // C99 6.9.2p3: If the declaration of an identifier for an object is
2753        // a tentative definition and has internal linkage (C99 6.2.2p3), the
2754        // declared type shall not be an incomplete type.
2755        IDecl->setInvalidDecl();
2756      }
2757    }
2758  }
2759  return DeclGroupPtrTy::make(DeclGroupRef::Create(Context,
2760                                                   &Decls[0], Decls.size()));
2761}
2762
2763
2764/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator()
2765/// to introduce parameters into function prototype scope.
2766Sema::DeclPtrTy
2767Sema::ActOnParamDeclarator(Scope *S, Declarator &D) {
2768  const DeclSpec &DS = D.getDeclSpec();
2769
2770  // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'.
2771  VarDecl::StorageClass StorageClass = VarDecl::None;
2772  if (DS.getStorageClassSpec() == DeclSpec::SCS_register) {
2773    StorageClass = VarDecl::Register;
2774  } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) {
2775    Diag(DS.getStorageClassSpecLoc(),
2776         diag::err_invalid_storage_class_in_func_decl);
2777    D.getMutableDeclSpec().ClearStorageClassSpecs();
2778  }
2779
2780  if (D.getDeclSpec().isThreadSpecified())
2781    Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread);
2782
2783  DiagnoseFunctionSpecifiers(D);
2784
2785  // Check that there are no default arguments inside the type of this
2786  // parameter (C++ only).
2787  if (getLangOptions().CPlusPlus)
2788    CheckExtraCXXDefaultArguments(D);
2789
2790  QualType parmDeclType = GetTypeForDeclarator(D, S);
2791
2792  // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
2793  // Can this happen for params?  We already checked that they don't conflict
2794  // among each other.  Here they can only shadow globals, which is ok.
2795  IdentifierInfo *II = D.getIdentifier();
2796  if (II) {
2797    if (NamedDecl *PrevDecl = LookupName(S, II, LookupOrdinaryName)) {
2798      if (PrevDecl->isTemplateParameter()) {
2799        // Maybe we will complain about the shadowed template parameter.
2800        DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
2801        // Just pretend that we didn't see the previous declaration.
2802        PrevDecl = 0;
2803      } else if (S->isDeclScope(DeclPtrTy::make(PrevDecl))) {
2804        Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II;
2805
2806        // Recover by removing the name
2807        II = 0;
2808        D.SetIdentifier(0, D.getIdentifierLoc());
2809      }
2810    }
2811  }
2812
2813  // Parameters can not be abstract class types.
2814  // For record types, this is done by the AbstractClassUsageDiagnoser once
2815  // the class has been completely parsed.
2816  if (!CurContext->isRecord() &&
2817      RequireNonAbstractType(D.getIdentifierLoc(), parmDeclType,
2818                             diag::err_abstract_type_in_decl,
2819                             AbstractParamType))
2820    D.setInvalidType(true);
2821
2822  QualType T = adjustParameterType(parmDeclType);
2823
2824  ParmVarDecl *New;
2825  if (T == parmDeclType) // parameter type did not need adjustment
2826    New = ParmVarDecl::Create(Context, CurContext,
2827                              D.getIdentifierLoc(), II,
2828                              parmDeclType, StorageClass,
2829                              0);
2830  else // keep track of both the adjusted and unadjusted types
2831    New = OriginalParmVarDecl::Create(Context, CurContext,
2832                                      D.getIdentifierLoc(), II, T,
2833                                      parmDeclType, StorageClass, 0);
2834
2835  if (D.isInvalidType())
2836    New->setInvalidDecl();
2837
2838  // Parameter declarators cannot be interface types. All ObjC objects are
2839  // passed by reference.
2840  if (T->isObjCInterfaceType()) {
2841    Diag(D.getIdentifierLoc(),
2842         diag::err_object_cannot_be_passed_returned_by_value) << 1 << T;
2843    New->setInvalidDecl();
2844  }
2845
2846  // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1).
2847  if (D.getCXXScopeSpec().isSet()) {
2848    Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator)
2849      << D.getCXXScopeSpec().getRange();
2850    New->setInvalidDecl();
2851  }
2852
2853  // Add the parameter declaration into this scope.
2854  S->AddDecl(DeclPtrTy::make(New));
2855  if (II)
2856    IdResolver.AddDecl(New);
2857
2858  ProcessDeclAttributes(New, D);
2859
2860  if (New->hasAttr<BlocksAttr>()) {
2861    Diag(New->getLocation(), diag::err_block_on_nonlocal);
2862  }
2863  return DeclPtrTy::make(New);
2864}
2865
2866void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D,
2867                                           SourceLocation LocAfterDecls) {
2868  assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function &&
2869         "Not a function declarator!");
2870  DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
2871
2872  // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared'
2873  // for a K&R function.
2874  if (!FTI.hasPrototype) {
2875    for (int i = FTI.NumArgs; i != 0; /* decrement in loop */) {
2876      --i;
2877      if (FTI.ArgInfo[i].Param == 0) {
2878        std::string Code = "  int ";
2879        Code += FTI.ArgInfo[i].Ident->getName();
2880        Code += ";\n";
2881        Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared)
2882          << FTI.ArgInfo[i].Ident
2883          << CodeModificationHint::CreateInsertion(LocAfterDecls, Code);
2884
2885        // Implicitly declare the argument as type 'int' for lack of a better
2886        // type.
2887        DeclSpec DS;
2888        const char* PrevSpec; // unused
2889        DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc,
2890                           PrevSpec);
2891        Declarator ParamD(DS, Declarator::KNRTypeListContext);
2892        ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc);
2893        FTI.ArgInfo[i].Param = ActOnParamDeclarator(S, ParamD);
2894      }
2895    }
2896  }
2897}
2898
2899Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope,
2900                                              Declarator &D) {
2901  assert(getCurFunctionDecl() == 0 && "Function parsing confused");
2902  assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function &&
2903         "Not a function declarator!");
2904  DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
2905
2906  if (FTI.hasPrototype) {
2907    // FIXME: Diagnose arguments without names in C.
2908  }
2909
2910  Scope *ParentScope = FnBodyScope->getParent();
2911
2912  DeclPtrTy DP = ActOnDeclarator(ParentScope, D, /*IsFunctionDefinition=*/true);
2913  return ActOnStartOfFunctionDef(FnBodyScope, DP);
2914}
2915
2916Sema::DeclPtrTy Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclPtrTy D) {
2917  FunctionDecl *FD = cast<FunctionDecl>(D.getAs<Decl>());
2918
2919  CurFunctionNeedsScopeChecking = false;
2920
2921  // See if this is a redefinition.
2922  const FunctionDecl *Definition;
2923  if (FD->getBody(Context, Definition)) {
2924    Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName();
2925    Diag(Definition->getLocation(), diag::note_previous_definition);
2926  }
2927
2928  // Builtin functions cannot be defined.
2929  if (unsigned BuiltinID = FD->getBuiltinID(Context)) {
2930    if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) {
2931      Diag(FD->getLocation(), diag::err_builtin_definition) << FD;
2932      FD->setInvalidDecl();
2933    }
2934  }
2935
2936  // The return type of a function definition must be complete
2937  // (C99 6.9.1p3, C++ [dcl.fct]p6).
2938  QualType ResultType = FD->getResultType();
2939  if (!ResultType->isDependentType() && !ResultType->isVoidType() &&
2940      !FD->isInvalidDecl() &&
2941      RequireCompleteType(FD->getLocation(), ResultType,
2942                          diag::err_func_def_incomplete_result))
2943    FD->setInvalidDecl();
2944
2945  // GNU warning -Wmissing-prototypes:
2946  //   Warn if a global function is defined without a previous
2947  //   prototype declaration. This warning is issued even if the
2948  //   definition itself provides a prototype. The aim is to detect
2949  //   global functions that fail to be declared in header files.
2950  if (!FD->isInvalidDecl() && FD->isGlobal() && !isa<CXXMethodDecl>(FD) &&
2951      !FD->isMain()) {
2952    bool MissingPrototype = true;
2953    for (const FunctionDecl *Prev = FD->getPreviousDeclaration();
2954         Prev; Prev = Prev->getPreviousDeclaration()) {
2955      // Ignore any declarations that occur in function or method
2956      // scope, because they aren't visible from the header.
2957      if (Prev->getDeclContext()->isFunctionOrMethod())
2958        continue;
2959
2960      MissingPrototype = !Prev->getType()->isFunctionProtoType();
2961      break;
2962    }
2963
2964    if (MissingPrototype)
2965      Diag(FD->getLocation(), diag::warn_missing_prototype) << FD;
2966  }
2967
2968  PushDeclContext(FnBodyScope, FD);
2969
2970  // Check the validity of our function parameters
2971  CheckParmsForFunctionDef(FD);
2972
2973  // Introduce our parameters into the function scope
2974  for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) {
2975    ParmVarDecl *Param = FD->getParamDecl(p);
2976    Param->setOwningFunction(FD);
2977
2978    // If this has an identifier, add it to the scope stack.
2979    if (Param->getIdentifier())
2980      PushOnScopeChains(Param, FnBodyScope);
2981  }
2982
2983  // Checking attributes of current function definition
2984  // dllimport attribute.
2985  if (FD->getAttr<DLLImportAttr>() && (!FD->getAttr<DLLExportAttr>())) {
2986    // dllimport attribute cannot be applied to definition.
2987    if (!(FD->getAttr<DLLImportAttr>())->isInherited()) {
2988      Diag(FD->getLocation(),
2989           diag::err_attribute_can_be_applied_only_to_symbol_declaration)
2990        << "dllimport";
2991      FD->setInvalidDecl();
2992      return DeclPtrTy::make(FD);
2993    } else {
2994      // If a symbol previously declared dllimport is later defined, the
2995      // attribute is ignored in subsequent references, and a warning is
2996      // emitted.
2997      Diag(FD->getLocation(),
2998           diag::warn_redeclaration_without_attribute_prev_attribute_ignored)
2999        << FD->getNameAsCString() << "dllimport";
3000    }
3001  }
3002  return DeclPtrTy::make(FD);
3003}
3004
3005
3006Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg) {
3007  Decl *dcl = D.getAs<Decl>();
3008  Stmt *Body = BodyArg.takeAs<Stmt>();
3009  if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) {
3010    FD->setBody(Body);
3011    assert(FD == getCurFunctionDecl() && "Function parsing confused");
3012  } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) {
3013    assert(MD == getCurMethodDecl() && "Method parsing confused");
3014    MD->setBody(Body);
3015  } else {
3016    Body->Destroy(Context);
3017    return DeclPtrTy();
3018  }
3019  PopDeclContext();
3020  // Verify and clean out per-function state.
3021
3022  assert(&getLabelMap() == &FunctionLabelMap && "Didn't pop block right?");
3023
3024  // Check goto/label use.
3025  for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator
3026       I = FunctionLabelMap.begin(), E = FunctionLabelMap.end(); I != E; ++I) {
3027    LabelStmt *L = I->second;
3028
3029    // Verify that we have no forward references left.  If so, there was a goto
3030    // or address of a label taken, but no definition of it.  Label fwd
3031    // definitions are indicated with a null substmt.
3032    if (L->getSubStmt() != 0)
3033      continue;
3034
3035    // Emit error.
3036    Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName();
3037
3038    // At this point, we have gotos that use the bogus label.  Stitch it into
3039    // the function body so that they aren't leaked and that the AST is well
3040    // formed.
3041    if (Body == 0) {
3042      // The whole function wasn't parsed correctly, just delete this.
3043      L->Destroy(Context);
3044      continue;
3045    }
3046
3047    // Otherwise, the body is valid: we want to stitch the label decl into the
3048    // function somewhere so that it is properly owned and so that the goto
3049    // has a valid target.  Do this by creating a new compound stmt with the
3050    // label in it.
3051
3052    // Give the label a sub-statement.
3053    L->setSubStmt(new (Context) NullStmt(L->getIdentLoc()));
3054
3055    CompoundStmt *Compound = isa<CXXTryStmt>(Body) ?
3056                               cast<CXXTryStmt>(Body)->getTryBlock() :
3057                               cast<CompoundStmt>(Body);
3058    std::vector<Stmt*> Elements(Compound->body_begin(), Compound->body_end());
3059    Elements.push_back(L);
3060    Compound->setStmts(Context, &Elements[0], Elements.size());
3061  }
3062  FunctionLabelMap.clear();
3063
3064  if (!Body) return D;
3065
3066  // Verify that that gotos and switch cases don't jump into scopes illegally.
3067  if (CurFunctionNeedsScopeChecking)
3068    DiagnoseInvalidJumps(Body);
3069
3070  // C++ constructors that have function-try-blocks can't have return statements
3071  // in the handlers of that block. (C++ [except.handle]p14) Verify this.
3072  if (isa<CXXConstructorDecl>(dcl) && isa<CXXTryStmt>(Body))
3073    DiagnoseReturnInConstructorExceptionHandler(cast<CXXTryStmt>(Body));
3074
3075  return D;
3076}
3077
3078/// ImplicitlyDefineFunction - An undeclared identifier was used in a function
3079/// call, forming a call to an implicitly defined function (per C99 6.5.1p2).
3080NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc,
3081                                          IdentifierInfo &II, Scope *S) {
3082  // Before we produce a declaration for an implicitly defined
3083  // function, see whether there was a locally-scoped declaration of
3084  // this name as a function or variable. If so, use that
3085  // (non-visible) declaration, and complain about it.
3086  llvm::DenseMap<DeclarationName, NamedDecl *>::iterator Pos
3087    = LocallyScopedExternalDecls.find(&II);
3088  if (Pos != LocallyScopedExternalDecls.end()) {
3089    Diag(Loc, diag::warn_use_out_of_scope_declaration) << Pos->second;
3090    Diag(Pos->second->getLocation(), diag::note_previous_declaration);
3091    return Pos->second;
3092  }
3093
3094  // Extension in C99.  Legal in C90, but warn about it.
3095  if (getLangOptions().C99)
3096    Diag(Loc, diag::ext_implicit_function_decl) << &II;
3097  else
3098    Diag(Loc, diag::warn_implicit_function_decl) << &II;
3099
3100  // FIXME: handle stuff like:
3101  // void foo() { extern float X(); }
3102  // void bar() { X(); }  <-- implicit decl for X in another scope.
3103
3104  // Set a Declarator for the implicit definition: int foo();
3105  const char *Dummy;
3106  DeclSpec DS;
3107  bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy);
3108  Error = Error; // Silence warning.
3109  assert(!Error && "Error setting up implicit decl!");
3110  Declarator D(DS, Declarator::BlockContext);
3111  D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, SourceLocation(), 0,
3112                                             0, 0, false, false, 0, 0, Loc, D),
3113                SourceLocation());
3114  D.SetIdentifier(&II, Loc);
3115
3116  // Insert this function into translation-unit scope.
3117
3118  DeclContext *PrevDC = CurContext;
3119  CurContext = Context.getTranslationUnitDecl();
3120
3121  FunctionDecl *FD =
3122 dyn_cast<FunctionDecl>(ActOnDeclarator(TUScope, D, DeclPtrTy()).getAs<Decl>());
3123  FD->setImplicit();
3124
3125  CurContext = PrevDC;
3126
3127  AddKnownFunctionAttributes(FD);
3128
3129  return FD;
3130}
3131
3132/// \brief Adds any function attributes that we know a priori based on
3133/// the declaration of this function.
3134///
3135/// These attributes can apply both to implicitly-declared builtins
3136/// (like __builtin___printf_chk) or to library-declared functions
3137/// like NSLog or printf.
3138void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) {
3139  if (FD->isInvalidDecl())
3140    return;
3141
3142  // If this is a built-in function, map its builtin attributes to
3143  // actual attributes.
3144  if (unsigned BuiltinID = FD->getBuiltinID(Context)) {
3145    // Handle printf-formatting attributes.
3146    unsigned FormatIdx;
3147    bool HasVAListArg;
3148    if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) {
3149      if (!FD->getAttr<FormatAttr>())
3150        FD->addAttr(::new (Context) FormatAttr("printf", FormatIdx + 1,
3151                                               FormatIdx + 2));
3152    }
3153
3154    // Mark const if we don't care about errno and that is the only
3155    // thing preventing the function from being const. This allows
3156    // IRgen to use LLVM intrinsics for such functions.
3157    if (!getLangOptions().MathErrno &&
3158        Context.BuiltinInfo.isConstWithoutErrno(BuiltinID)) {
3159      if (!FD->getAttr<ConstAttr>())
3160        FD->addAttr(::new (Context) ConstAttr());
3161    }
3162  }
3163
3164  IdentifierInfo *Name = FD->getIdentifier();
3165  if (!Name)
3166    return;
3167  if ((!getLangOptions().CPlusPlus &&
3168       FD->getDeclContext()->isTranslationUnit()) ||
3169      (isa<LinkageSpecDecl>(FD->getDeclContext()) &&
3170       cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage() ==
3171       LinkageSpecDecl::lang_c)) {
3172    // Okay: this could be a libc/libm/Objective-C function we know
3173    // about.
3174  } else
3175    return;
3176
3177  if (Name->isStr("NSLog") || Name->isStr("NSLogv")) {
3178    if (const FormatAttr *Format = FD->getAttr<FormatAttr>()) {
3179      // FIXME: We known better than our headers.
3180      const_cast<FormatAttr *>(Format)->setType("printf");
3181    } else
3182      FD->addAttr(::new (Context) FormatAttr("printf", 1, 2));
3183  } else if (Name->isStr("asprintf") || Name->isStr("vasprintf")) {
3184    if (!FD->getAttr<FormatAttr>())
3185      FD->addAttr(::new (Context) FormatAttr("printf", 2, 3));
3186  }
3187}
3188
3189TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T) {
3190  assert(D.getIdentifier() && "Wrong callback for declspec without declarator");
3191  assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
3192
3193  // Scope manipulation handled by caller.
3194  TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext,
3195                                           D.getIdentifierLoc(),
3196                                           D.getIdentifier(),
3197                                           T);
3198
3199  if (TagType *TT = dyn_cast<TagType>(T)) {
3200    TagDecl *TD = TT->getDecl();
3201
3202    // If the TagDecl that the TypedefDecl points to is an anonymous decl
3203    // keep track of the TypedefDecl.
3204    if (!TD->getIdentifier() && !TD->getTypedefForAnonDecl())
3205      TD->setTypedefForAnonDecl(NewTD);
3206  }
3207
3208  if (D.isInvalidType())
3209    NewTD->setInvalidDecl();
3210  return NewTD;
3211}
3212
3213/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'.  In the
3214/// former case, Name will be non-null.  In the later case, Name will be null.
3215/// TagSpec indicates what kind of tag this is. TK indicates whether this is a
3216/// reference/declaration/definition of a tag.
3217Sema::DeclPtrTy Sema::ActOnTag(Scope *S, unsigned TagSpec, TagKind TK,
3218                               SourceLocation KWLoc, const CXXScopeSpec &SS,
3219                               IdentifierInfo *Name, SourceLocation NameLoc,
3220                               AttributeList *Attr, AccessSpecifier AS) {
3221  // If this is not a definition, it must have a name.
3222  assert((Name != 0 || TK == TK_Definition) &&
3223         "Nameless record must be a definition!");
3224
3225  TagDecl::TagKind Kind;
3226  switch (TagSpec) {
3227  default: assert(0 && "Unknown tag type!");
3228  case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break;
3229  case DeclSpec::TST_union:  Kind = TagDecl::TK_union; break;
3230  case DeclSpec::TST_class:  Kind = TagDecl::TK_class; break;
3231  case DeclSpec::TST_enum:   Kind = TagDecl::TK_enum; break;
3232  }
3233
3234  DeclContext *SearchDC = CurContext;
3235  DeclContext *DC = CurContext;
3236  NamedDecl *PrevDecl = 0;
3237
3238  bool Invalid = false;
3239
3240  if (Name && SS.isNotEmpty()) {
3241    // We have a nested-name tag ('struct foo::bar').
3242
3243    // Check for invalid 'foo::'.
3244    if (SS.isInvalid()) {
3245      Name = 0;
3246      goto CreateNewDecl;
3247    }
3248
3249    // FIXME: RequireCompleteDeclContext(SS)?
3250    DC = computeDeclContext(SS);
3251    SearchDC = DC;
3252    // Look-up name inside 'foo::'.
3253    PrevDecl = dyn_cast_or_null<TagDecl>(
3254                 LookupQualifiedName(DC, Name, LookupTagName, true).getAsDecl());
3255
3256    // A tag 'foo::bar' must already exist.
3257    if (PrevDecl == 0) {
3258      Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange();
3259      Name = 0;
3260      goto CreateNewDecl;
3261    }
3262  } else if (Name) {
3263    // If this is a named struct, check to see if there was a previous forward
3264    // declaration or definition.
3265    // FIXME: We're looking into outer scopes here, even when we
3266    // shouldn't be. Doing so can result in ambiguities that we
3267    // shouldn't be diagnosing.
3268    LookupResult R = LookupName(S, Name, LookupTagName,
3269                                /*RedeclarationOnly=*/(TK != TK_Reference));
3270    if (R.isAmbiguous()) {
3271      DiagnoseAmbiguousLookup(R, Name, NameLoc);
3272      // FIXME: This is not best way to recover from case like:
3273      //
3274      // struct S s;
3275      //
3276      // causes needless "incomplete type" error later.
3277      Name = 0;
3278      PrevDecl = 0;
3279      Invalid = true;
3280    }
3281    else
3282      PrevDecl = R;
3283
3284    if (!getLangOptions().CPlusPlus && TK != TK_Reference) {
3285      // FIXME: This makes sure that we ignore the contexts associated
3286      // with C structs, unions, and enums when looking for a matching
3287      // tag declaration or definition. See the similar lookup tweak
3288      // in Sema::LookupName; is there a better way to deal with this?
3289      while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC))
3290        SearchDC = SearchDC->getParent();
3291    }
3292  }
3293
3294  if (PrevDecl && PrevDecl->isTemplateParameter()) {
3295    // Maybe we will complain about the shadowed template parameter.
3296    DiagnoseTemplateParameterShadow(NameLoc, PrevDecl);
3297    // Just pretend that we didn't see the previous declaration.
3298    PrevDecl = 0;
3299  }
3300
3301  if (PrevDecl) {
3302    // Check whether the previous declaration is usable.
3303    (void)DiagnoseUseOfDecl(PrevDecl, NameLoc);
3304
3305    if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) {
3306      // If this is a use of a previous tag, or if the tag is already declared
3307      // in the same scope (so that the definition/declaration completes or
3308      // rementions the tag), reuse the decl.
3309      if (TK == TK_Reference || isDeclInScope(PrevDecl, SearchDC, S)) {
3310        // Make sure that this wasn't declared as an enum and now used as a
3311        // struct or something similar.
3312        if (!isAcceptableTagRedeclaration(PrevTagDecl->getTagKind(), Kind)) {
3313          bool SafeToContinue
3314            = (PrevTagDecl->getTagKind() != TagDecl::TK_enum &&
3315               Kind != TagDecl::TK_enum);
3316          if (SafeToContinue)
3317            Diag(KWLoc, diag::err_use_with_wrong_tag)
3318              << Name
3319              << CodeModificationHint::CreateReplacement(SourceRange(KWLoc),
3320                                                  PrevTagDecl->getKindName());
3321          else
3322            Diag(KWLoc, diag::err_use_with_wrong_tag) << Name;
3323          Diag(PrevDecl->getLocation(), diag::note_previous_use);
3324
3325          if (SafeToContinue)
3326            Kind = PrevTagDecl->getTagKind();
3327          else {
3328            // Recover by making this an anonymous redefinition.
3329            Name = 0;
3330            PrevDecl = 0;
3331            Invalid = true;
3332          }
3333        }
3334
3335        if (!Invalid) {
3336          // If this is a use, just return the declaration we found.
3337
3338          // FIXME: In the future, return a variant or some other clue
3339          // for the consumer of this Decl to know it doesn't own it.
3340          // For our current ASTs this shouldn't be a problem, but will
3341          // need to be changed with DeclGroups.
3342          if (TK == TK_Reference)
3343            return DeclPtrTy::make(PrevDecl);
3344
3345          // Diagnose attempts to redefine a tag.
3346          if (TK == TK_Definition) {
3347            if (TagDecl *Def = PrevTagDecl->getDefinition(Context)) {
3348              Diag(NameLoc, diag::err_redefinition) << Name;
3349              Diag(Def->getLocation(), diag::note_previous_definition);
3350              // If this is a redefinition, recover by making this
3351              // struct be anonymous, which will make any later
3352              // references get the previous definition.
3353              Name = 0;
3354              PrevDecl = 0;
3355              Invalid = true;
3356            } else {
3357              // If the type is currently being defined, complain
3358              // about a nested redefinition.
3359              TagType *Tag = cast<TagType>(Context.getTagDeclType(PrevTagDecl));
3360              if (Tag->isBeingDefined()) {
3361                Diag(NameLoc, diag::err_nested_redefinition) << Name;
3362                Diag(PrevTagDecl->getLocation(),
3363                     diag::note_previous_definition);
3364                Name = 0;
3365                PrevDecl = 0;
3366                Invalid = true;
3367              }
3368            }
3369
3370            // Okay, this is definition of a previously declared or referenced
3371            // tag PrevDecl. We're going to create a new Decl for it.
3372          }
3373        }
3374        // If we get here we have (another) forward declaration or we
3375        // have a definition.  Just create a new decl.
3376      } else {
3377        // If we get here, this is a definition of a new tag type in a nested
3378        // scope, e.g. "struct foo; void bar() { struct foo; }", just create a
3379        // new decl/type.  We set PrevDecl to NULL so that the entities
3380        // have distinct types.
3381        PrevDecl = 0;
3382      }
3383      // If we get here, we're going to create a new Decl. If PrevDecl
3384      // is non-NULL, it's a definition of the tag declared by
3385      // PrevDecl. If it's NULL, we have a new definition.
3386    } else {
3387      // PrevDecl is a namespace, template, or anything else
3388      // that lives in the IDNS_Tag identifier namespace.
3389      if (isDeclInScope(PrevDecl, SearchDC, S)) {
3390        // The tag name clashes with a namespace name, issue an error and
3391        // recover by making this tag be anonymous.
3392        Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
3393        Diag(PrevDecl->getLocation(), diag::note_previous_definition);
3394        Name = 0;
3395        PrevDecl = 0;
3396        Invalid = true;
3397      } else {
3398        // The existing declaration isn't relevant to us; we're in a
3399        // new scope, so clear out the previous declaration.
3400        PrevDecl = 0;
3401      }
3402    }
3403  } else if (TK == TK_Reference && SS.isEmpty() && Name &&
3404             (Kind != TagDecl::TK_enum || !getLangOptions().CPlusPlus)) {
3405    // C.scope.pdecl]p5:
3406    //   -- for an elaborated-type-specifier of the form
3407    //
3408    //          class-key identifier
3409    //
3410    //      if the elaborated-type-specifier is used in the
3411    //      decl-specifier-seq or parameter-declaration-clause of a
3412    //      function defined in namespace scope, the identifier is
3413    //      declared as a class-name in the namespace that contains
3414    //      the declaration; otherwise, except as a friend
3415    //      declaration, the identifier is declared in the smallest
3416    //      non-class, non-function-prototype scope that contains the
3417    //      declaration.
3418    //
3419    // C99 6.7.2.3p8 has a similar (but not identical!) provision for
3420    // C structs and unions.
3421    //
3422    // GNU C also supports this behavior as part of its incomplete
3423    // enum types extension, while GNU C++ does not.
3424    //
3425    // Find the context where we'll be declaring the tag.
3426    // FIXME: We would like to maintain the current DeclContext as the
3427    // lexical context,
3428    while (SearchDC->isRecord())
3429      SearchDC = SearchDC->getParent();
3430
3431    // Find the scope where we'll be declaring the tag.
3432    while (S->isClassScope() ||
3433           (getLangOptions().CPlusPlus && S->isFunctionPrototypeScope()) ||
3434           ((S->getFlags() & Scope::DeclScope) == 0) ||
3435           (S->getEntity() &&
3436            ((DeclContext *)S->getEntity())->isTransparentContext()))
3437      S = S->getParent();
3438  }
3439
3440CreateNewDecl:
3441
3442  // If there is an identifier, use the location of the identifier as the
3443  // location of the decl, otherwise use the location of the struct/union
3444  // keyword.
3445  SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
3446
3447  // Otherwise, create a new declaration. If there is a previous
3448  // declaration of the same entity, the two will be linked via
3449  // PrevDecl.
3450  TagDecl *New;
3451
3452  if (Kind == TagDecl::TK_enum) {
3453    // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
3454    // enum X { A, B, C } D;    D should chain to X.
3455    New = EnumDecl::Create(Context, SearchDC, Loc, Name,
3456                           cast_or_null<EnumDecl>(PrevDecl));
3457    // If this is an undefined enum, warn.
3458    if (TK != TK_Definition && !Invalid)  {
3459      unsigned DK = getLangOptions().CPlusPlus? diag::err_forward_ref_enum
3460                                              : diag::ext_forward_ref_enum;
3461      Diag(Loc, DK);
3462    }
3463  } else {
3464    // struct/union/class
3465
3466    // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
3467    // struct X { int A; } D;    D should chain to X.
3468    if (getLangOptions().CPlusPlus)
3469      // FIXME: Look for a way to use RecordDecl for simple structs.
3470      New = CXXRecordDecl::Create(Context, Kind, SearchDC, Loc, Name,
3471                                  cast_or_null<CXXRecordDecl>(PrevDecl));
3472    else
3473      New = RecordDecl::Create(Context, Kind, SearchDC, Loc, Name,
3474                               cast_or_null<RecordDecl>(PrevDecl));
3475  }
3476
3477  if (Kind != TagDecl::TK_enum) {
3478    // Handle #pragma pack: if the #pragma pack stack has non-default
3479    // alignment, make up a packed attribute for this decl. These
3480    // attributes are checked when the ASTContext lays out the
3481    // structure.
3482    //
3483    // It is important for implementing the correct semantics that this
3484    // happen here (in act on tag decl). The #pragma pack stack is
3485    // maintained as a result of parser callbacks which can occur at
3486    // many points during the parsing of a struct declaration (because
3487    // the #pragma tokens are effectively skipped over during the
3488    // parsing of the struct).
3489    if (unsigned Alignment = getPragmaPackAlignment())
3490      New->addAttr(::new (Context) PackedAttr(Alignment * 8));
3491  }
3492
3493  if (getLangOptions().CPlusPlus && SS.isEmpty() && Name && !Invalid) {
3494    // C++ [dcl.typedef]p3:
3495    //   [...] Similarly, in a given scope, a class or enumeration
3496    //   shall not be declared with the same name as a typedef-name
3497    //   that is declared in that scope and refers to a type other
3498    //   than the class or enumeration itself.
3499    LookupResult Lookup = LookupName(S, Name, LookupOrdinaryName, true);
3500    TypedefDecl *PrevTypedef = 0;
3501    if (Lookup.getKind() == LookupResult::Found)
3502      PrevTypedef = dyn_cast<TypedefDecl>(Lookup.getAsDecl());
3503
3504    if (PrevTypedef && isDeclInScope(PrevTypedef, SearchDC, S) &&
3505        Context.getCanonicalType(Context.getTypeDeclType(PrevTypedef)) !=
3506          Context.getCanonicalType(Context.getTypeDeclType(New))) {
3507      Diag(Loc, diag::err_tag_definition_of_typedef)
3508        << Context.getTypeDeclType(New)
3509        << PrevTypedef->getUnderlyingType();
3510      Diag(PrevTypedef->getLocation(), diag::note_previous_definition);
3511      Invalid = true;
3512    }
3513  }
3514
3515  if (Invalid)
3516    New->setInvalidDecl();
3517
3518  if (Attr)
3519    ProcessDeclAttributeList(New, Attr);
3520
3521  // If we're declaring or defining a tag in function prototype scope
3522  // in C, note that this type can only be used within the function.
3523  if (Name && S->isFunctionPrototypeScope() && !getLangOptions().CPlusPlus)
3524    Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New);
3525
3526  // Set the lexical context. If the tag has a C++ scope specifier, the
3527  // lexical context will be different from the semantic context.
3528  New->setLexicalDeclContext(CurContext);
3529
3530  // Set the access specifier.
3531  SetMemberAccessSpecifier(New, PrevDecl, AS);
3532
3533  if (TK == TK_Definition)
3534    New->startDefinition();
3535
3536  // If this has an identifier, add it to the scope stack.
3537  if (Name) {
3538    S = getNonFieldDeclScope(S);
3539    PushOnScopeChains(New, S);
3540  } else {
3541    CurContext->addDecl(Context, New);
3542  }
3543
3544  return DeclPtrTy::make(New);
3545}
3546
3547void Sema::ActOnTagStartDefinition(Scope *S, DeclPtrTy TagD) {
3548  AdjustDeclIfTemplate(TagD);
3549  TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>());
3550
3551  // Enter the tag context.
3552  PushDeclContext(S, Tag);
3553
3554  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Tag)) {
3555    FieldCollector->StartClass();
3556
3557    if (Record->getIdentifier()) {
3558      // C++ [class]p2:
3559      //   [...] The class-name is also inserted into the scope of the
3560      //   class itself; this is known as the injected-class-name. For
3561      //   purposes of access checking, the injected-class-name is treated
3562      //   as if it were a public member name.
3563      CXXRecordDecl *InjectedClassName
3564        = CXXRecordDecl::Create(Context, Record->getTagKind(),
3565                                CurContext, Record->getLocation(),
3566                                Record->getIdentifier(), Record);
3567      InjectedClassName->setImplicit();
3568      InjectedClassName->setAccess(AS_public);
3569      if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate())
3570        InjectedClassName->setDescribedClassTemplate(Template);
3571      PushOnScopeChains(InjectedClassName, S);
3572      assert(InjectedClassName->isInjectedClassName() &&
3573             "Broken injected-class-name");
3574    }
3575  }
3576}
3577
3578void Sema::ActOnTagFinishDefinition(Scope *S, DeclPtrTy TagD) {
3579  AdjustDeclIfTemplate(TagD);
3580  TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>());
3581
3582  if (isa<CXXRecordDecl>(Tag))
3583    FieldCollector->FinishClass();
3584
3585  // Exit this scope of this tag's definition.
3586  PopDeclContext();
3587
3588  // Notify the consumer that we've defined a tag.
3589  Consumer.HandleTagDeclDefinition(Tag);
3590}
3591
3592// Note that FieldName may be null for anonymous bitfields.
3593bool Sema::VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName,
3594                          QualType FieldTy, const Expr *BitWidth) {
3595
3596  // C99 6.7.2.1p4 - verify the field type.
3597  // C++ 9.6p3: A bit-field shall have integral or enumeration type.
3598  if (!FieldTy->isDependentType() && !FieldTy->isIntegralType()) {
3599    // Handle incomplete types with specific error.
3600    if (RequireCompleteType(FieldLoc, FieldTy, diag::err_field_incomplete))
3601      return true;
3602    if (FieldName)
3603      return Diag(FieldLoc, diag::err_not_integral_type_bitfield)
3604        << FieldName << FieldTy << BitWidth->getSourceRange();
3605    return Diag(FieldLoc, diag::err_not_integral_type_anon_bitfield)
3606      << FieldTy << BitWidth->getSourceRange();
3607  }
3608
3609  // If the bit-width is type- or value-dependent, don't try to check
3610  // it now.
3611  if (BitWidth->isValueDependent() || BitWidth->isTypeDependent())
3612    return false;
3613
3614  llvm::APSInt Value;
3615  if (VerifyIntegerConstantExpression(BitWidth, &Value))
3616    return true;
3617
3618  // Zero-width bitfield is ok for anonymous field.
3619  if (Value == 0 && FieldName)
3620    return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName;
3621
3622  if (Value.isSigned() && Value.isNegative()) {
3623    if (FieldName)
3624      return Diag(FieldLoc, diag::err_bitfield_has_negative_width)
3625               << FieldName << Value.toString(10);
3626    return Diag(FieldLoc, diag::err_anon_bitfield_has_negative_width)
3627      << Value.toString(10);
3628  }
3629
3630  if (!FieldTy->isDependentType()) {
3631    uint64_t TypeSize = Context.getTypeSize(FieldTy);
3632    if (Value.getZExtValue() > TypeSize) {
3633      if (FieldName)
3634        return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_size)
3635          << FieldName << (unsigned)TypeSize;
3636      return Diag(FieldLoc, diag::err_anon_bitfield_width_exceeds_type_size)
3637        << (unsigned)TypeSize;
3638    }
3639  }
3640
3641  return false;
3642}
3643
3644/// ActOnField - Each field of a struct/union/class is passed into this in order
3645/// to create a FieldDecl object for it.
3646Sema::DeclPtrTy Sema::ActOnField(Scope *S, DeclPtrTy TagD,
3647                                 SourceLocation DeclStart,
3648                                 Declarator &D, ExprTy *BitfieldWidth) {
3649  FieldDecl *Res = HandleField(S, cast_or_null<RecordDecl>(TagD.getAs<Decl>()),
3650                               DeclStart, D, static_cast<Expr*>(BitfieldWidth),
3651                               AS_public);
3652  return DeclPtrTy::make(Res);
3653}
3654
3655/// HandleField - Analyze a field of a C struct or a C++ data member.
3656///
3657FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record,
3658                             SourceLocation DeclStart,
3659                             Declarator &D, Expr *BitWidth,
3660                             AccessSpecifier AS) {
3661  IdentifierInfo *II = D.getIdentifier();
3662  SourceLocation Loc = DeclStart;
3663  if (II) Loc = D.getIdentifierLoc();
3664
3665  QualType T = GetTypeForDeclarator(D, S);
3666  if (getLangOptions().CPlusPlus)
3667    CheckExtraCXXDefaultArguments(D);
3668
3669  DiagnoseFunctionSpecifiers(D);
3670
3671  if (D.getDeclSpec().isThreadSpecified())
3672    Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread);
3673
3674  NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true);
3675  if (PrevDecl && !isDeclInScope(PrevDecl, Record, S))
3676    PrevDecl = 0;
3677
3678  FieldDecl *NewFD
3679    = CheckFieldDecl(II, T, Record, Loc,
3680               D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_mutable,
3681                     BitWidth, AS, PrevDecl, &D);
3682  if (NewFD->isInvalidDecl() && PrevDecl) {
3683    // Don't introduce NewFD into scope; there's already something
3684    // with the same name in the same scope.
3685  } else if (II) {
3686    PushOnScopeChains(NewFD, S);
3687  } else
3688    Record->addDecl(Context, NewFD);
3689
3690  return NewFD;
3691}
3692
3693/// \brief Build a new FieldDecl and check its well-formedness.
3694///
3695/// This routine builds a new FieldDecl given the fields name, type,
3696/// record, etc. \p PrevDecl should refer to any previous declaration
3697/// with the same name and in the same scope as the field to be
3698/// created.
3699///
3700/// \returns a new FieldDecl.
3701///
3702/// \todo The Declarator argument is a hack. It will be removed once
3703FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T,
3704                                RecordDecl *Record, SourceLocation Loc,
3705                                bool Mutable, Expr *BitWidth,
3706                                AccessSpecifier AS, NamedDecl *PrevDecl,
3707                                Declarator *D) {
3708  IdentifierInfo *II = Name.getAsIdentifierInfo();
3709  bool InvalidDecl = false;
3710  if (D) InvalidDecl = D->isInvalidType();
3711
3712  // If we receive a broken type, recover by assuming 'int' and
3713  // marking this declaration as invalid.
3714  if (T.isNull()) {
3715    InvalidDecl = true;
3716    T = Context.IntTy;
3717  }
3718
3719  // C99 6.7.2.1p8: A member of a structure or union may have any type other
3720  // than a variably modified type.
3721  if (T->isVariablyModifiedType()) {
3722    bool SizeIsNegative;
3723    QualType FixedTy = TryToFixInvalidVariablyModifiedType(T, Context,
3724                                                           SizeIsNegative);
3725    if (!FixedTy.isNull()) {
3726      Diag(Loc, diag::warn_illegal_constant_array_size);
3727      T = FixedTy;
3728    } else {
3729      if (SizeIsNegative)
3730        Diag(Loc, diag::err_typecheck_negative_array_size);
3731      else
3732        Diag(Loc, diag::err_typecheck_field_variable_size);
3733      T = Context.IntTy;
3734      InvalidDecl = true;
3735    }
3736  }
3737
3738  // Fields can not have abstract class types
3739  if (RequireNonAbstractType(Loc, T, diag::err_abstract_type_in_decl,
3740                             AbstractFieldType))
3741    InvalidDecl = true;
3742
3743  // If this is declared as a bit-field, check the bit-field.
3744  if (BitWidth && VerifyBitField(Loc, II, T, BitWidth)) {
3745    InvalidDecl = true;
3746    DeleteExpr(BitWidth);
3747    BitWidth = 0;
3748  }
3749
3750  FieldDecl *NewFD = FieldDecl::Create(Context, Record, Loc, II, T, BitWidth,
3751                                       Mutable);
3752  if (InvalidDecl)
3753    NewFD->setInvalidDecl();
3754
3755  if (PrevDecl && !isa<TagDecl>(PrevDecl)) {
3756    Diag(Loc, diag::err_duplicate_member) << II;
3757    Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
3758    NewFD->setInvalidDecl();
3759  }
3760
3761  if (getLangOptions().CPlusPlus && !T->isPODType())
3762    cast<CXXRecordDecl>(Record)->setPOD(false);
3763
3764  // FIXME: We need to pass in the attributes given an AST
3765  // representation, not a parser representation.
3766  if (D)
3767    ProcessDeclAttributes(NewFD, *D);
3768
3769  if (T.isObjCGCWeak())
3770    Diag(Loc, diag::warn_attribute_weak_on_field);
3771
3772  NewFD->setAccess(AS);
3773
3774  // C++ [dcl.init.aggr]p1:
3775  //   An aggregate is an array or a class (clause 9) with [...] no
3776  //   private or protected non-static data members (clause 11).
3777  // A POD must be an aggregate.
3778  if (getLangOptions().CPlusPlus &&
3779      (AS == AS_private || AS == AS_protected)) {
3780    CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record);
3781    CXXRecord->setAggregate(false);
3782    CXXRecord->setPOD(false);
3783  }
3784
3785  return NewFD;
3786}
3787
3788/// TranslateIvarVisibility - Translate visibility from a token ID to an
3789///  AST enum value.
3790static ObjCIvarDecl::AccessControl
3791TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) {
3792  switch (ivarVisibility) {
3793  default: assert(0 && "Unknown visitibility kind");
3794  case tok::objc_private: return ObjCIvarDecl::Private;
3795  case tok::objc_public: return ObjCIvarDecl::Public;
3796  case tok::objc_protected: return ObjCIvarDecl::Protected;
3797  case tok::objc_package: return ObjCIvarDecl::Package;
3798  }
3799}
3800
3801/// ActOnIvar - Each ivar field of an objective-c class is passed into this
3802/// in order to create an IvarDecl object for it.
3803Sema::DeclPtrTy Sema::ActOnIvar(Scope *S,
3804                                SourceLocation DeclStart,
3805                                Declarator &D, ExprTy *BitfieldWidth,
3806                                tok::ObjCKeywordKind Visibility) {
3807
3808  IdentifierInfo *II = D.getIdentifier();
3809  Expr *BitWidth = (Expr*)BitfieldWidth;
3810  SourceLocation Loc = DeclStart;
3811  if (II) Loc = D.getIdentifierLoc();
3812
3813  // FIXME: Unnamed fields can be handled in various different ways, for
3814  // example, unnamed unions inject all members into the struct namespace!
3815
3816  QualType T = GetTypeForDeclarator(D, S);
3817
3818  if (BitWidth) {
3819    // 6.7.2.1p3, 6.7.2.1p4
3820    if (VerifyBitField(Loc, II, T, BitWidth)) {
3821      D.setInvalidType();
3822      DeleteExpr(BitWidth);
3823      BitWidth = 0;
3824    }
3825  } else {
3826    // Not a bitfield.
3827
3828    // validate II.
3829
3830  }
3831
3832  // C99 6.7.2.1p8: A member of a structure or union may have any type other
3833  // than a variably modified type.
3834  if (T->isVariablyModifiedType()) {
3835    Diag(Loc, diag::err_typecheck_ivar_variable_size);
3836    D.setInvalidType();
3837  }
3838
3839  // Get the visibility (access control) for this ivar.
3840  ObjCIvarDecl::AccessControl ac =
3841    Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility)
3842                                        : ObjCIvarDecl::None;
3843
3844  // Construct the decl.
3845  ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, CurContext, Loc, II, T,ac,
3846                                             (Expr *)BitfieldWidth);
3847
3848  if (II) {
3849    NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true);
3850    if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S)
3851        && !isa<TagDecl>(PrevDecl)) {
3852      Diag(Loc, diag::err_duplicate_member) << II;
3853      Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
3854      NewID->setInvalidDecl();
3855    }
3856  }
3857
3858  // Process attributes attached to the ivar.
3859  ProcessDeclAttributes(NewID, D);
3860
3861  if (D.isInvalidType())
3862    NewID->setInvalidDecl();
3863
3864  if (II) {
3865    // FIXME: When interfaces are DeclContexts, we'll need to add
3866    // these to the interface.
3867    S->AddDecl(DeclPtrTy::make(NewID));
3868    IdResolver.AddDecl(NewID);
3869  }
3870
3871  return DeclPtrTy::make(NewID);
3872}
3873
3874void Sema::ActOnFields(Scope* S,
3875                       SourceLocation RecLoc, DeclPtrTy RecDecl,
3876                       DeclPtrTy *Fields, unsigned NumFields,
3877                       SourceLocation LBrac, SourceLocation RBrac,
3878                       AttributeList *Attr) {
3879  Decl *EnclosingDecl = RecDecl.getAs<Decl>();
3880  assert(EnclosingDecl && "missing record or interface decl");
3881
3882  // If the decl this is being inserted into is invalid, then it may be a
3883  // redeclaration or some other bogus case.  Don't try to add fields to it.
3884  if (EnclosingDecl->isInvalidDecl()) {
3885    // FIXME: Deallocate fields?
3886    return;
3887  }
3888
3889
3890  // Verify that all the fields are okay.
3891  unsigned NumNamedMembers = 0;
3892  llvm::SmallVector<FieldDecl*, 32> RecFields;
3893
3894  RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl);
3895  for (unsigned i = 0; i != NumFields; ++i) {
3896    FieldDecl *FD = cast<FieldDecl>(Fields[i].getAs<Decl>());
3897
3898    // Get the type for the field.
3899    Type *FDTy = FD->getType().getTypePtr();
3900
3901    if (!FD->isAnonymousStructOrUnion()) {
3902      // Remember all fields written by the user.
3903      RecFields.push_back(FD);
3904    }
3905
3906    // If the field is already invalid for some reason, don't emit more
3907    // diagnostics about it.
3908    if (FD->isInvalidDecl())
3909      continue;
3910
3911    // C99 6.7.2.1p2:
3912    //   A structure or union shall not contain a member with
3913    //   incomplete or function type (hence, a structure shall not
3914    //   contain an instance of itself, but may contain a pointer to
3915    //   an instance of itself), except that the last member of a
3916    //   structure with more than one named member may have incomplete
3917    //   array type; such a structure (and any union containing,
3918    //   possibly recursively, a member that is such a structure)
3919    //   shall not be a member of a structure or an element of an
3920    //   array.
3921    if (FDTy->isFunctionType()) {
3922      // Field declared as a function.
3923      Diag(FD->getLocation(), diag::err_field_declared_as_function)
3924        << FD->getDeclName();
3925      FD->setInvalidDecl();
3926      EnclosingDecl->setInvalidDecl();
3927      continue;
3928    } else if (FDTy->isIncompleteArrayType() && i == NumFields - 1 &&
3929               Record && Record->isStruct()) {
3930      // Flexible array member.
3931      if (NumNamedMembers < 1) {
3932        Diag(FD->getLocation(), diag::err_flexible_array_empty_struct)
3933          << FD->getDeclName();
3934        FD->setInvalidDecl();
3935        EnclosingDecl->setInvalidDecl();
3936        continue;
3937      }
3938      // Okay, we have a legal flexible array member at the end of the struct.
3939      if (Record)
3940        Record->setHasFlexibleArrayMember(true);
3941    } else if (!FDTy->isDependentType() &&
3942               RequireCompleteType(FD->getLocation(), FD->getType(),
3943                                   diag::err_field_incomplete)) {
3944      // Incomplete type
3945      FD->setInvalidDecl();
3946      EnclosingDecl->setInvalidDecl();
3947      continue;
3948    } else if (const RecordType *FDTTy = FDTy->getAsRecordType()) {
3949      if (FDTTy->getDecl()->hasFlexibleArrayMember()) {
3950        // If this is a member of a union, then entire union becomes "flexible".
3951        if (Record && Record->isUnion()) {
3952          Record->setHasFlexibleArrayMember(true);
3953        } else {
3954          // If this is a struct/class and this is not the last element, reject
3955          // it.  Note that GCC supports variable sized arrays in the middle of
3956          // structures.
3957          if (i != NumFields-1)
3958            Diag(FD->getLocation(), diag::ext_variable_sized_type_in_struct)
3959              << FD->getDeclName() << FD->getType();
3960          else {
3961            // We support flexible arrays at the end of structs in
3962            // other structs as an extension.
3963            Diag(FD->getLocation(), diag::ext_flexible_array_in_struct)
3964              << FD->getDeclName();
3965            if (Record)
3966              Record->setHasFlexibleArrayMember(true);
3967          }
3968        }
3969      }
3970    } else if (FDTy->isObjCInterfaceType()) {
3971      /// A field cannot be an Objective-c object
3972      Diag(FD->getLocation(), diag::err_statically_allocated_object);
3973      FD->setInvalidDecl();
3974      EnclosingDecl->setInvalidDecl();
3975      continue;
3976    }
3977    // Keep track of the number of named members.
3978    if (FD->getIdentifier())
3979      ++NumNamedMembers;
3980  }
3981
3982  // Okay, we successfully defined 'Record'.
3983  if (Record) {
3984    Record->completeDefinition(Context);
3985  } else {
3986    ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]);
3987    if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) {
3988      ID->setIVarList(ClsFields, RecFields.size(), Context);
3989      ID->setLocEnd(RBrac);
3990
3991      // Must enforce the rule that ivars in the base classes may not be
3992      // duplicates.
3993      if (ID->getSuperClass()) {
3994        for (ObjCInterfaceDecl::ivar_iterator IVI = ID->ivar_begin(),
3995             IVE = ID->ivar_end(); IVI != IVE; ++IVI) {
3996          ObjCIvarDecl* Ivar = (*IVI);
3997
3998          if (IdentifierInfo *II = Ivar->getIdentifier()) {
3999            ObjCIvarDecl* prevIvar =
4000              ID->getSuperClass()->lookupInstanceVariable(Context, II);
4001            if (prevIvar) {
4002              Diag(Ivar->getLocation(), diag::err_duplicate_member) << II;
4003              Diag(prevIvar->getLocation(), diag::note_previous_declaration);
4004            }
4005          }
4006        }
4007      }
4008    } else if (ObjCImplementationDecl *IMPDecl =
4009                  dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) {
4010      assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl");
4011      for (unsigned I = 0, N = RecFields.size(); I != N; ++I) {
4012        // FIXME: Set the DeclContext correctly when we build the
4013        // declarations.
4014        ClsFields[I]->setLexicalDeclContext(IMPDecl);
4015        IMPDecl->addDecl(Context, ClsFields[I]);
4016      }
4017      CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac);
4018    }
4019  }
4020
4021  if (Attr)
4022    ProcessDeclAttributeList(Record, Attr);
4023}
4024
4025EnumConstantDecl *Sema::CheckEnumConstant(EnumDecl *Enum,
4026                                          EnumConstantDecl *LastEnumConst,
4027                                          SourceLocation IdLoc,
4028                                          IdentifierInfo *Id,
4029                                          ExprArg val) {
4030  Expr *Val = (Expr *)val.get();
4031
4032  llvm::APSInt EnumVal(32);
4033  QualType EltTy;
4034  if (Val && !Val->isTypeDependent()) {
4035    // Make sure to promote the operand type to int.
4036    UsualUnaryConversions(Val);
4037    if (Val != val.get()) {
4038      val.release();
4039      val = Val;
4040    }
4041
4042    // C99 6.7.2.2p2: Make sure we have an integer constant expression.
4043    SourceLocation ExpLoc;
4044    if (!Val->isValueDependent() &&
4045        VerifyIntegerConstantExpression(Val, &EnumVal)) {
4046      Val = 0;
4047    } else {
4048      EltTy = Val->getType();
4049    }
4050  }
4051
4052  if (!Val) {
4053    if (LastEnumConst) {
4054      // Assign the last value + 1.
4055      EnumVal = LastEnumConst->getInitVal();
4056      ++EnumVal;
4057
4058      // Check for overflow on increment.
4059      if (EnumVal < LastEnumConst->getInitVal())
4060        Diag(IdLoc, diag::warn_enum_value_overflow);
4061
4062      EltTy = LastEnumConst->getType();
4063    } else {
4064      // First value, set to zero.
4065      EltTy = Context.IntTy;
4066      EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy)));
4067    }
4068  }
4069
4070  val.release();
4071  return EnumConstantDecl::Create(Context, Enum, IdLoc, Id, EltTy,
4072                                  Val, EnumVal);
4073}
4074
4075
4076Sema::DeclPtrTy Sema::ActOnEnumConstant(Scope *S, DeclPtrTy theEnumDecl,
4077                                        DeclPtrTy lastEnumConst,
4078                                        SourceLocation IdLoc,
4079                                        IdentifierInfo *Id,
4080                                        SourceLocation EqualLoc, ExprTy *val) {
4081  EnumDecl *TheEnumDecl = cast<EnumDecl>(theEnumDecl.getAs<Decl>());
4082  EnumConstantDecl *LastEnumConst =
4083    cast_or_null<EnumConstantDecl>(lastEnumConst.getAs<Decl>());
4084  Expr *Val = static_cast<Expr*>(val);
4085
4086  // The scope passed in may not be a decl scope.  Zip up the scope tree until
4087  // we find one that is.
4088  S = getNonFieldDeclScope(S);
4089
4090  // Verify that there isn't already something declared with this name in this
4091  // scope.
4092  NamedDecl *PrevDecl = LookupName(S, Id, LookupOrdinaryName);
4093  if (PrevDecl && PrevDecl->isTemplateParameter()) {
4094    // Maybe we will complain about the shadowed template parameter.
4095    DiagnoseTemplateParameterShadow(IdLoc, PrevDecl);
4096    // Just pretend that we didn't see the previous declaration.
4097    PrevDecl = 0;
4098  }
4099
4100  if (PrevDecl) {
4101    // When in C++, we may get a TagDecl with the same name; in this case the
4102    // enum constant will 'hide' the tag.
4103    assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) &&
4104           "Received TagDecl when not in C++!");
4105    if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) {
4106      if (isa<EnumConstantDecl>(PrevDecl))
4107        Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id;
4108      else
4109        Diag(IdLoc, diag::err_redefinition) << Id;
4110      Diag(PrevDecl->getLocation(), diag::note_previous_definition);
4111      if (Val) Val->Destroy(Context);
4112      return DeclPtrTy();
4113    }
4114  }
4115
4116  EnumConstantDecl *New = CheckEnumConstant(TheEnumDecl, LastEnumConst,
4117                                            IdLoc, Id, Owned(Val));
4118
4119  // Register this decl in the current scope stack.
4120  if (New)
4121    PushOnScopeChains(New, S);
4122
4123  return DeclPtrTy::make(New);
4124}
4125
4126// FIXME: For consistency with ActOnFields(), we should have the parser
4127// pass in the source location for the left/right braces.
4128void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclPtrTy EnumDeclX,
4129                         DeclPtrTy *Elements, unsigned NumElements) {
4130  EnumDecl *Enum = cast<EnumDecl>(EnumDeclX.getAs<Decl>());
4131  QualType EnumType = Context.getTypeDeclType(Enum);
4132
4133  // TODO: If the result value doesn't fit in an int, it must be a long or long
4134  // long value.  ISO C does not support this, but GCC does as an extension,
4135  // emit a warning.
4136  unsigned IntWidth = Context.Target.getIntWidth();
4137
4138  // Verify that all the values are okay, compute the size of the values, and
4139  // reverse the list.
4140  unsigned NumNegativeBits = 0;
4141  unsigned NumPositiveBits = 0;
4142
4143  // Keep track of whether all elements have type int.
4144  bool AllElementsInt = true;
4145
4146  for (unsigned i = 0; i != NumElements; ++i) {
4147    EnumConstantDecl *ECD =
4148      cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>());
4149    if (!ECD) continue;  // Already issued a diagnostic.
4150
4151    // If the enum value doesn't fit in an int, emit an extension warning.
4152    const llvm::APSInt &InitVal = ECD->getInitVal();
4153    assert(InitVal.getBitWidth() >= IntWidth &&
4154           "Should have promoted value to int");
4155    if (InitVal.getBitWidth() > IntWidth) {
4156      llvm::APSInt V(InitVal);
4157      V.trunc(IntWidth);
4158      V.extend(InitVal.getBitWidth());
4159      if (V != InitVal)
4160        Diag(ECD->getLocation(), diag::ext_enum_value_not_int)
4161          << InitVal.toString(10);
4162    }
4163
4164    // Keep track of the size of positive and negative values.
4165    if (InitVal.isUnsigned() || InitVal.isNonNegative())
4166      NumPositiveBits = std::max(NumPositiveBits,
4167                                 (unsigned)InitVal.getActiveBits());
4168    else
4169      NumNegativeBits = std::max(NumNegativeBits,
4170                                 (unsigned)InitVal.getMinSignedBits());
4171
4172    // Keep track of whether every enum element has type int (very commmon).
4173    if (AllElementsInt)
4174      AllElementsInt = ECD->getType() == Context.IntTy;
4175  }
4176
4177  // Figure out the type that should be used for this enum.
4178  // FIXME: Support attribute(packed) on enums and -fshort-enums.
4179  QualType BestType;
4180  unsigned BestWidth;
4181
4182  if (NumNegativeBits) {
4183    // If there is a negative value, figure out the smallest integer type (of
4184    // int/long/longlong) that fits.
4185    if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) {
4186      BestType = Context.IntTy;
4187      BestWidth = IntWidth;
4188    } else {
4189      BestWidth = Context.Target.getLongWidth();
4190
4191      if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth)
4192        BestType = Context.LongTy;
4193      else {
4194        BestWidth = Context.Target.getLongLongWidth();
4195
4196        if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth)
4197          Diag(Enum->getLocation(), diag::warn_enum_too_large);
4198        BestType = Context.LongLongTy;
4199      }
4200    }
4201  } else {
4202    // If there is no negative value, figure out which of uint, ulong, ulonglong
4203    // fits.
4204    if (NumPositiveBits <= IntWidth) {
4205      BestType = Context.UnsignedIntTy;
4206      BestWidth = IntWidth;
4207    } else if (NumPositiveBits <=
4208               (BestWidth = Context.Target.getLongWidth())) {
4209      BestType = Context.UnsignedLongTy;
4210    } else {
4211      BestWidth = Context.Target.getLongLongWidth();
4212      assert(NumPositiveBits <= BestWidth &&
4213             "How could an initializer get larger than ULL?");
4214      BestType = Context.UnsignedLongLongTy;
4215    }
4216  }
4217
4218  // Loop over all of the enumerator constants, changing their types to match
4219  // the type of the enum if needed.
4220  for (unsigned i = 0; i != NumElements; ++i) {
4221    EnumConstantDecl *ECD =
4222      cast_or_null<EnumConstantDecl>(Elements[i].getAs<Decl>());
4223    if (!ECD) continue;  // Already issued a diagnostic.
4224
4225    // Standard C says the enumerators have int type, but we allow, as an
4226    // extension, the enumerators to be larger than int size.  If each
4227    // enumerator value fits in an int, type it as an int, otherwise type it the
4228    // same as the enumerator decl itself.  This means that in "enum { X = 1U }"
4229    // that X has type 'int', not 'unsigned'.
4230    if (ECD->getType() == Context.IntTy) {
4231      // Make sure the init value is signed.
4232      llvm::APSInt IV = ECD->getInitVal();
4233      IV.setIsSigned(true);
4234      ECD->setInitVal(IV);
4235
4236      if (getLangOptions().CPlusPlus)
4237        // C++ [dcl.enum]p4: Following the closing brace of an
4238        // enum-specifier, each enumerator has the type of its
4239        // enumeration.
4240        ECD->setType(EnumType);
4241      continue;  // Already int type.
4242    }
4243
4244    // Determine whether the value fits into an int.
4245    llvm::APSInt InitVal = ECD->getInitVal();
4246    bool FitsInInt;
4247    if (InitVal.isUnsigned() || !InitVal.isNegative())
4248      FitsInInt = InitVal.getActiveBits() < IntWidth;
4249    else
4250      FitsInInt = InitVal.getMinSignedBits() <= IntWidth;
4251
4252    // If it fits into an integer type, force it.  Otherwise force it to match
4253    // the enum decl type.
4254    QualType NewTy;
4255    unsigned NewWidth;
4256    bool NewSign;
4257    if (FitsInInt) {
4258      NewTy = Context.IntTy;
4259      NewWidth = IntWidth;
4260      NewSign = true;
4261    } else if (ECD->getType() == BestType) {
4262      // Already the right type!
4263      if (getLangOptions().CPlusPlus)
4264        // C++ [dcl.enum]p4: Following the closing brace of an
4265        // enum-specifier, each enumerator has the type of its
4266        // enumeration.
4267        ECD->setType(EnumType);
4268      continue;
4269    } else {
4270      NewTy = BestType;
4271      NewWidth = BestWidth;
4272      NewSign = BestType->isSignedIntegerType();
4273    }
4274
4275    // Adjust the APSInt value.
4276    InitVal.extOrTrunc(NewWidth);
4277    InitVal.setIsSigned(NewSign);
4278    ECD->setInitVal(InitVal);
4279
4280    // Adjust the Expr initializer and type.
4281    if (ECD->getInitExpr())
4282      ECD->setInitExpr(new (Context) ImplicitCastExpr(NewTy, ECD->getInitExpr(),
4283                                                      /*isLvalue=*/false));
4284    if (getLangOptions().CPlusPlus)
4285      // C++ [dcl.enum]p4: Following the closing brace of an
4286      // enum-specifier, each enumerator has the type of its
4287      // enumeration.
4288      ECD->setType(EnumType);
4289    else
4290      ECD->setType(NewTy);
4291  }
4292
4293  Enum->completeDefinition(Context, BestType);
4294}
4295
4296Sema::DeclPtrTy Sema::ActOnFileScopeAsmDecl(SourceLocation Loc,
4297                                            ExprArg expr) {
4298  StringLiteral *AsmString = cast<StringLiteral>(expr.takeAs<Expr>());
4299
4300  return DeclPtrTy::make(FileScopeAsmDecl::Create(Context, CurContext,
4301                                                  Loc, AsmString));
4302}
4303