SemaDecl.cpp revision f009795057dc8ca254f5618c80a0a90f07cd44b4
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/ASTConsumer.h"
16#include "clang/AST/ASTContext.h"
17#include "clang/AST/Attr.h"
18#include "clang/AST/Builtins.h"
19#include "clang/AST/Decl.h"
20#include "clang/AST/Expr.h"
21#include "clang/AST/Type.h"
22#include "clang/Parse/DeclSpec.h"
23#include "clang/Parse/Scope.h"
24#include "clang/Basic/LangOptions.h"
25#include "clang/Basic/TargetInfo.h"
26#include "clang/Basic/SourceManager.h"
27// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's)
28#include "clang/Lex/Preprocessor.h"
29#include "clang/Lex/HeaderSearch.h"
30#include "llvm/ADT/SmallString.h"
31#include "llvm/ADT/SmallSet.h"
32#include "llvm/ADT/DenseSet.h"
33using namespace clang;
34
35Sema::DeclTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S) {
36  Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, false);
37
38  if (IIDecl && (isa<TypedefDecl>(IIDecl) ||
39                 isa<ObjCInterfaceDecl>(IIDecl) ||
40                 isa<TagDecl>(IIDecl)))
41    return IIDecl;
42  return 0;
43}
44
45void Sema::PushDeclContext(DeclContext *CD) {
46  assert( ( (CD->isFunctionOrMethod() && isa<TranslationUnitDecl>(CurContext))
47            || CD->getParent() == CurContext ) &&
48      "The next DeclContext should be directly contained in the current one.");
49  CurContext = CD;
50}
51
52void Sema::PopDeclContext() {
53  assert(CurContext && "DeclContext imbalance!");
54  // If CurContext is a ObjC method, getParent() will return NULL.
55  CurContext = CurContext->isFunctionOrMethod()
56               ? Context.getTranslationUnitDecl()
57                 :  CurContext->getParent();
58}
59
60/// Add this decl to the scope shadowed decl chains.
61void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) {
62  IdResolver.AddDecl(D, S);
63  S->AddDecl(D);
64}
65
66void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) {
67  if (S->decl_empty()) return;
68  assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!");
69
70  for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end();
71       I != E; ++I) {
72    Decl *TmpD = static_cast<Decl*>(*I);
73    assert(TmpD && "This decl didn't get pushed??");
74    ScopedDecl *D = dyn_cast<ScopedDecl>(TmpD);
75    assert(D && "This decl isn't a ScopedDecl?");
76
77    IdentifierInfo *II = D->getIdentifier();
78    if (!II) continue;
79
80    // Unlink this decl from the identifier.
81    IdResolver.RemoveDecl(D);
82
83    // This will have to be revisited for C++: there we want to nest stuff in
84    // namespace decls etc.  Even for C, we might want a top-level translation
85    // unit decl or something.
86    if (!CurFunctionDecl)
87      continue;
88
89    // Chain this decl to the containing function, it now owns the memory for
90    // the decl.
91    D->setNext(CurFunctionDecl->getDeclChain());
92    CurFunctionDecl->setDeclChain(D);
93  }
94}
95
96/// getObjCInterfaceDecl - Look up a for a class declaration in the scope.
97/// return 0 if one not found.
98ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) {
99  // The third "scope" argument is 0 since we aren't enabling lazy built-in
100  // creation from this context.
101  Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false);
102
103  return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl);
104}
105
106/// LookupDecl - Look up the inner-most declaration in the specified
107/// namespace.
108Decl *Sema::LookupDecl(const IdentifierInfo *II, unsigned NSI,
109                       Scope *S, bool enableLazyBuiltinCreation) {
110  if (II == 0) return 0;
111  unsigned NS = NSI;
112  if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary))
113    NS |= Decl::IDNS_Tag;
114
115  // Scan up the scope chain looking for a decl that matches this identifier
116  // that is in the appropriate namespace.  This search should not take long, as
117  // shadowing of names is uncommon, and deep shadowing is extremely uncommon.
118  NamedDecl *ND = IdResolver.Lookup(II, NS);
119  if (ND) return ND;
120
121  // If we didn't find a use of this identifier, and if the identifier
122  // corresponds to a compiler builtin, create the decl object for the builtin
123  // now, injecting it into translation unit scope, and return it.
124  if (NS & Decl::IDNS_Ordinary) {
125    if (enableLazyBuiltinCreation) {
126      // If this is a builtin on this (or all) targets, create the decl.
127      if (unsigned BuiltinID = II->getBuiltinID())
128        return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S);
129    }
130    if (getLangOptions().ObjC1) {
131      // @interface and @compatibility_alias introduce typedef-like names.
132      // Unlike typedef's, they can only be introduced at file-scope (and are
133      // therefore not scoped decls). They can, however, be shadowed by
134      // other names in IDNS_Ordinary.
135      ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II);
136      if (IDI != ObjCInterfaceDecls.end())
137        return IDI->second;
138      ObjCAliasTy::iterator I = ObjCAliasDecls.find(II);
139      if (I != ObjCAliasDecls.end())
140        return I->second->getClassInterface();
141    }
142  }
143  return 0;
144}
145
146void Sema::InitBuiltinVaListType()
147{
148  if (!Context.getBuiltinVaListType().isNull())
149    return;
150
151  IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list");
152  Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope);
153  TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl);
154  Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef));
155}
156
157/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope.
158/// lazily create a decl for it.
159ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid,
160                                      Scope *S) {
161  Builtin::ID BID = (Builtin::ID)bid;
162
163  if (BID == Builtin::BI__builtin_va_start ||
164       BID == Builtin::BI__builtin_va_copy ||
165       BID == Builtin::BI__builtin_va_end)
166    InitBuiltinVaListType();
167
168  QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context);
169  FunctionDecl *New = FunctionDecl::Create(Context,
170                                           Context.getTranslationUnitDecl(),
171                                           SourceLocation(), II, R,
172                                           FunctionDecl::Extern, false, 0);
173
174  // TUScope is the translation-unit scope to insert this function into.
175  TUScope->AddDecl(New);
176
177  // Add this decl to the end of the identifier info.
178  IdResolver.AddGlobalDecl(New);
179
180  return New;
181}
182
183/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name
184/// and scope as a previous declaration 'Old'.  Figure out how to resolve this
185/// situation, merging decls or emitting diagnostics as appropriate.
186///
187TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) {
188  // Verify the old decl was also a typedef.
189  TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD);
190  if (!Old) {
191    Diag(New->getLocation(), diag::err_redefinition_different_kind,
192         New->getName());
193    Diag(OldD->getLocation(), diag::err_previous_definition);
194    return New;
195  }
196
197  // Allow multiple definitions for ObjC built-in typedefs.
198  // FIXME: Verify the underlying types are equivalent!
199  if (getLangOptions().ObjC1 && isBuiltinObjCType(New))
200    return Old;
201
202  // Redeclaration of a type is a constraint violation (6.7.2.3p1).
203  // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if
204  // *either* declaration is in a system header. The code below implements
205  // this adhoc compatibility rule. FIXME: The following code will not
206  // work properly when compiling ".i" files (containing preprocessed output).
207  SourceManager &SrcMgr = Context.getSourceManager();
208  const FileEntry *OldDeclFile = SrcMgr.getFileEntryForLoc(Old->getLocation());
209  const FileEntry *NewDeclFile = SrcMgr.getFileEntryForLoc(New->getLocation());
210  HeaderSearch &HdrInfo = PP.getHeaderSearchInfo();
211  DirectoryLookup::DirType OldDirType = HdrInfo.getFileDirFlavor(OldDeclFile);
212  DirectoryLookup::DirType NewDirType = HdrInfo.getFileDirFlavor(NewDeclFile);
213
214  // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir.
215  if ((OldDirType != DirectoryLookup::NormalHeaderDir ||
216       NewDirType != DirectoryLookup::NormalHeaderDir) ||
217      getLangOptions().Microsoft)
218    return New;
219
220  // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
221  // TODO: This is totally simplistic.  It should handle merging functions
222  // together etc, merging extern int X; int X; ...
223  Diag(New->getLocation(), diag::err_redefinition, New->getName());
224  Diag(Old->getLocation(), diag::err_previous_definition);
225  return New;
226}
227
228/// DeclhasAttr - returns true if decl Declaration already has the target attribute.
229static bool DeclHasAttr(const Decl *decl, const Attr *target) {
230  for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext())
231    if (attr->getKind() == target->getKind())
232      return true;
233
234  return false;
235}
236
237/// MergeAttributes - append attributes from the Old decl to the New one.
238static void MergeAttributes(Decl *New, Decl *Old) {
239  Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp;
240
241// FIXME: fix this code to cleanup the Old attrs correctly
242  while (attr) {
243     tmp = attr;
244     attr = attr->getNext();
245
246    if (!DeclHasAttr(New, tmp)) {
247       New->addAttr(tmp);
248    } else {
249       tmp->setNext(0);
250       delete(tmp);
251    }
252  }
253}
254
255/// MergeFunctionDecl - We just parsed a function 'New' from
256/// declarator D which has the same name and scope as a previous
257/// declaration 'Old'.  Figure out how to resolve this situation,
258/// merging decls or emitting diagnostics as appropriate.
259/// Redeclaration will be set true if thisNew is a redeclaration OldD.
260FunctionDecl *
261Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) {
262  Redeclaration = false;
263  // Verify the old decl was also a function.
264  FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD);
265  if (!Old) {
266    Diag(New->getLocation(), diag::err_redefinition_different_kind,
267         New->getName());
268    Diag(OldD->getLocation(), diag::err_previous_definition);
269    return New;
270  }
271
272  QualType OldQType = Context.getCanonicalType(Old->getType());
273  QualType NewQType = Context.getCanonicalType(New->getType());
274
275  // C++ [dcl.fct]p3:
276  //   All declarations for a function shall agree exactly in both the
277  //   return type and the parameter-type-list.
278  if (getLangOptions().CPlusPlus && OldQType == NewQType) {
279    MergeAttributes(New, Old);
280    Redeclaration = true;
281    return MergeCXXFunctionDecl(New, Old);
282  }
283
284  // C: Function types need to be compatible, not identical. This handles
285  // duplicate function decls like "void f(int); void f(enum X);" properly.
286  if (!getLangOptions().CPlusPlus &&
287      Context.functionTypesAreCompatible(OldQType, NewQType)) {
288    MergeAttributes(New, Old);
289    Redeclaration = true;
290    return New;
291  }
292
293  // A function that has already been declared has been redeclared or defined
294  // with a different type- show appropriate diagnostic
295  diag::kind PrevDiag;
296  if (Old->isThisDeclarationADefinition())
297    PrevDiag = diag::err_previous_definition;
298  else if (Old->isImplicit())
299    PrevDiag = diag::err_previous_implicit_declaration;
300  else
301    PrevDiag = diag::err_previous_declaration;
302
303  // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
304  // TODO: This is totally simplistic.  It should handle merging functions
305  // together etc, merging extern int X; int X; ...
306  Diag(New->getLocation(), diag::err_conflicting_types, New->getName());
307  Diag(Old->getLocation(), PrevDiag);
308  return New;
309}
310
311/// equivalentArrayTypes - Used to determine whether two array types are
312/// equivalent.
313/// We need to check this explicitly as an incomplete array definition is
314/// considered a VariableArrayType, so will not match a complete array
315/// definition that would be otherwise equivalent.
316static bool areEquivalentArrayTypes(QualType NewQType, QualType OldQType) {
317  const ArrayType *NewAT = NewQType->getAsArrayType();
318  const ArrayType *OldAT = OldQType->getAsArrayType();
319
320  if (!NewAT || !OldAT)
321    return false;
322
323  // If either (or both) array types in incomplete we need to strip off the
324  // outer VariableArrayType.  Once the outer VAT is removed the remaining
325  // types must be identical if the array types are to be considered
326  // equivalent.
327  // eg. int[][1] and int[1][1] become
328  //     VAT(null, CAT(1, int)) and CAT(1, CAT(1, int))
329  // removing the outermost VAT gives
330  //     CAT(1, int) and CAT(1, int)
331  // which are equal, therefore the array types are equivalent.
332  if (NewAT->isIncompleteArrayType() || OldAT->isIncompleteArrayType()) {
333    if (NewAT->getIndexTypeQualifier() != OldAT->getIndexTypeQualifier())
334      return false;
335    NewQType = NewAT->getElementType().getCanonicalType();
336    OldQType = OldAT->getElementType().getCanonicalType();
337  }
338
339  return NewQType == OldQType;
340}
341
342/// MergeVarDecl - We just parsed a variable 'New' which has the same name
343/// and scope as a previous declaration 'Old'.  Figure out how to resolve this
344/// situation, merging decls or emitting diagnostics as appropriate.
345///
346/// FIXME: Need to carefully consider tentative definition rules (C99 6.9.2p2).
347/// For example, we incorrectly complain about i1, i4 from C99 6.9.2p4.
348///
349VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) {
350  // Verify the old decl was also a variable.
351  VarDecl *Old = dyn_cast<VarDecl>(OldD);
352  if (!Old) {
353    Diag(New->getLocation(), diag::err_redefinition_different_kind,
354         New->getName());
355    Diag(OldD->getLocation(), diag::err_previous_definition);
356    return New;
357  }
358
359  MergeAttributes(New, Old);
360
361  // Verify the types match.
362  QualType OldCType = Context.getCanonicalType(Old->getType());
363  QualType NewCType = Context.getCanonicalType(New->getType());
364  if (OldCType != NewCType && !areEquivalentArrayTypes(NewCType, OldCType)) {
365    Diag(New->getLocation(), diag::err_redefinition, New->getName());
366    Diag(Old->getLocation(), diag::err_previous_definition);
367    return New;
368  }
369  // C99 6.2.2p4: Check if we have a static decl followed by a non-static.
370  if (New->getStorageClass() == VarDecl::Static &&
371      (Old->getStorageClass() == VarDecl::None ||
372       Old->getStorageClass() == VarDecl::Extern)) {
373    Diag(New->getLocation(), diag::err_static_non_static, New->getName());
374    Diag(Old->getLocation(), diag::err_previous_definition);
375    return New;
376  }
377  // C99 6.2.2p4: Check if we have a non-static decl followed by a static.
378  if (New->getStorageClass() != VarDecl::Static &&
379      Old->getStorageClass() == VarDecl::Static) {
380    Diag(New->getLocation(), diag::err_non_static_static, New->getName());
381    Diag(Old->getLocation(), diag::err_previous_definition);
382    return New;
383  }
384  // We've verified the types match, now handle "tentative" definitions.
385  if (Old->isFileVarDecl() && New->isFileVarDecl()) {
386    // Handle C "tentative" external object definitions (C99 6.9.2).
387    bool OldIsTentative = false;
388    bool NewIsTentative = false;
389
390    if (!Old->getInit() &&
391        (Old->getStorageClass() == VarDecl::None ||
392         Old->getStorageClass() == VarDecl::Static))
393      OldIsTentative = true;
394
395    // FIXME: this check doesn't work (since the initializer hasn't been
396    // attached yet). This check should be moved to FinalizeDeclaratorGroup.
397    // Unfortunately, by the time we get to FinializeDeclaratorGroup, we've
398    // thrown out the old decl.
399    if (!New->getInit() &&
400        (New->getStorageClass() == VarDecl::None ||
401         New->getStorageClass() == VarDecl::Static))
402      ; // change to NewIsTentative = true; once the code is moved.
403
404    if (NewIsTentative || OldIsTentative)
405      return New;
406  }
407  if (Old->getStorageClass() != VarDecl::Extern &&
408      New->getStorageClass() != VarDecl::Extern) {
409    Diag(New->getLocation(), diag::err_redefinition, New->getName());
410    Diag(Old->getLocation(), diag::err_previous_definition);
411  }
412  return New;
413}
414
415/// CheckParmsForFunctionDef - Check that the parameters of the given
416/// function are appropriate for the definition of a function. This
417/// takes care of any checks that cannot be performed on the
418/// declaration itself, e.g., that the types of each of the function
419/// parameters are complete.
420bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) {
421  bool HasInvalidParm = false;
422  for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) {
423    ParmVarDecl *Param = FD->getParamDecl(p);
424
425    // C99 6.7.5.3p4: the parameters in a parameter type list in a
426    // function declarator that is part of a function definition of
427    // that function shall not have incomplete type.
428    if (Param->getType()->isIncompleteType() &&
429        !Param->isInvalidDecl()) {
430      Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type,
431           Param->getType().getAsString());
432      Param->setInvalidDecl();
433      HasInvalidParm = true;
434    }
435  }
436
437  return HasInvalidParm;
438}
439
440/// CreateImplicitParameter - Creates an implicit function parameter
441/// in the scope S and with the given type. This routine is used, for
442/// example, to create the implicit "self" parameter in an Objective-C
443/// method.
444ParmVarDecl *
445Sema::CreateImplicitParameter(Scope *S, IdentifierInfo *Id,
446                              SourceLocation IdLoc, QualType Type) {
447  ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, IdLoc, Id, Type,
448                                         VarDecl::None, 0, 0);
449  if (Id)
450    PushOnScopeChains(New, S);
451
452  return New;
453}
454
455/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
456/// no declarator (e.g. "struct foo;") is parsed.
457Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) {
458  // TODO: emit error on 'int;' or 'const enum foo;'.
459  // TODO: emit error on 'typedef int;'
460  // if (!DS.isMissingDeclaratorOk()) Diag(...);
461
462  return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep()));
463}
464
465bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) {
466  // Get the type before calling CheckSingleAssignmentConstraints(), since
467  // it can promote the expression.
468  QualType InitType = Init->getType();
469
470  AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init);
471  return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType,
472                                  InitType, Init, "initializing");
473}
474
475bool Sema::CheckInitExpr(Expr *expr, InitListExpr *IList, unsigned slot,
476                         QualType ElementType) {
477  Expr *savExpr = expr; // Might be promoted by CheckSingleInitializer.
478  if (CheckSingleInitializer(expr, ElementType))
479    return true; // types weren't compatible.
480
481  if (savExpr != expr) // The type was promoted, update initializer list.
482    IList->setInit(slot, expr);
483  return false;
484}
485
486bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) {
487  if (const IncompleteArrayType *IAT = DeclT->getAsIncompleteArrayType()) {
488    // C99 6.7.8p14. We have an array of character type with unknown size
489    // being initialized to a string literal.
490    llvm::APSInt ConstVal(32);
491    ConstVal = strLiteral->getByteLength() + 1;
492    // Return a new array type (C99 6.7.8p22).
493    DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal,
494                                         ArrayType::Normal, 0);
495  } else if (const ConstantArrayType *CAT = DeclT->getAsConstantArrayType()) {
496    // C99 6.7.8p14. We have an array of character type with known size.
497    if (strLiteral->getByteLength() > (unsigned)CAT->getMaximumElements())
498      Diag(strLiteral->getSourceRange().getBegin(),
499           diag::warn_initializer_string_for_char_array_too_long,
500           strLiteral->getSourceRange());
501  } else {
502    assert(0 && "HandleStringLiteralInit(): Invalid array type");
503  }
504  // Set type from "char *" to "constant array of char".
505  strLiteral->setType(DeclT);
506  // For now, we always return false (meaning success).
507  return false;
508}
509
510StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) {
511  const ArrayType *AT = DeclType->getAsArrayType();
512  if (AT && AT->getElementType()->isCharType()) {
513    return dyn_cast<StringLiteral>(Init);
514  }
515  return 0;
516}
517
518// CheckInitializerListTypes - Checks the types of elements of an initializer
519// list. This function is recursive: it calls itself to initialize subelements
520// of aggregate types.  Note that the topLevel parameter essentially refers to
521// whether this expression "owns" the initializer list passed in, or if this
522// initialization is taking elements out of a parent initializer.  Each
523// call to this function adds zero or more to startIndex, reports any errors,
524// and returns true if it found any inconsistent types.
525bool Sema::CheckInitializerListTypes(InitListExpr*& IList, QualType &DeclType,
526                                     bool topLevel, unsigned& startIndex) {
527  bool hadError = false;
528
529  if (DeclType->isScalarType()) {
530    // The simplest case: initializing a single scalar
531    if (topLevel) {
532      Diag(IList->getLocStart(), diag::warn_braces_around_scalar_init,
533           IList->getSourceRange());
534    }
535    if (startIndex < IList->getNumInits()) {
536      Expr* expr = IList->getInit(startIndex);
537      if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) {
538        // FIXME: Should an error be reported here instead?
539        unsigned newIndex = 0;
540        CheckInitializerListTypes(SubInitList, DeclType, true, newIndex);
541      } else {
542        hadError |= CheckInitExpr(expr, IList, startIndex, DeclType);
543      }
544      ++startIndex;
545    }
546    // FIXME: Should an error be reported for empty initializer list + scalar?
547  } else if (DeclType->isVectorType()) {
548    if (startIndex < IList->getNumInits()) {
549      const VectorType *VT = DeclType->getAsVectorType();
550      int maxElements = VT->getNumElements();
551      QualType elementType = VT->getElementType();
552
553      for (int i = 0; i < maxElements; ++i) {
554        // Don't attempt to go past the end of the init list
555        if (startIndex >= IList->getNumInits())
556          break;
557        Expr* expr = IList->getInit(startIndex);
558        if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) {
559          unsigned newIndex = 0;
560          hadError |= CheckInitializerListTypes(SubInitList, elementType,
561                                                true, newIndex);
562          ++startIndex;
563        } else {
564          hadError |= CheckInitializerListTypes(IList, elementType,
565                                                false, startIndex);
566        }
567      }
568    }
569  } else if (DeclType->isAggregateType() || DeclType->isUnionType()) {
570    if (DeclType->isStructureType() || DeclType->isUnionType()) {
571      if (startIndex < IList->getNumInits() && !topLevel &&
572          Context.typesAreCompatible(IList->getInit(startIndex)->getType(),
573                                     DeclType)) {
574        // We found a compatible struct; per the standard, this initializes the
575        // struct.  (The C standard technically says that this only applies for
576        // initializers for declarations with automatic scope; however, this
577        // construct is unambiguous anyway because a struct cannot contain
578        // a type compatible with itself. We'll output an error when we check
579        // if the initializer is constant.)
580        // FIXME: Is a call to CheckSingleInitializer required here?
581        ++startIndex;
582      } else {
583        RecordDecl* structDecl = DeclType->getAsRecordType()->getDecl();
584
585        // If the record is invalid, some of it's members are invalid. To avoid
586        // confusion, we forgo checking the intializer for the entire record.
587        if (structDecl->isInvalidDecl())
588          return true;
589
590        // If structDecl is a forward declaration, this loop won't do anything;
591        // That's okay, because an error should get printed out elsewhere. It
592        // might be worthwhile to skip over the rest of the initializer, though.
593        int numMembers = structDecl->getNumMembers() -
594                         structDecl->hasFlexibleArrayMember();
595        for (int i = 0; i < numMembers; i++) {
596          // Don't attempt to go past the end of the init list
597          if (startIndex >= IList->getNumInits())
598            break;
599          FieldDecl * curField = structDecl->getMember(i);
600          if (!curField->getIdentifier()) {
601            // Don't initialize unnamed fields, e.g. "int : 20;"
602            continue;
603          }
604          QualType fieldType = curField->getType();
605          Expr* expr = IList->getInit(startIndex);
606          if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) {
607            unsigned newStart = 0;
608            hadError |= CheckInitializerListTypes(SubInitList, fieldType,
609                                                  true, newStart);
610            ++startIndex;
611          } else {
612            hadError |= CheckInitializerListTypes(IList, fieldType,
613                                                  false, startIndex);
614          }
615          if (DeclType->isUnionType())
616            break;
617        }
618        // FIXME: Implement flexible array initialization GCC extension (it's a
619        // really messy extension to implement, unfortunately...the necessary
620        // information isn't actually even here!)
621      }
622    } else if (DeclType->isArrayType()) {
623      // Check for the special-case of initializing an array with a string.
624      if (startIndex < IList->getNumInits()) {
625        if (StringLiteral *lit = IsStringLiteralInit(IList->getInit(startIndex),
626                                                     DeclType)) {
627          CheckStringLiteralInit(lit, DeclType);
628          ++startIndex;
629          if (topLevel && startIndex < IList->getNumInits()) {
630            // We have leftover initializers; warn
631            Diag(IList->getInit(startIndex)->getLocStart(),
632                 diag::err_excess_initializers_in_char_array_initializer,
633                 IList->getInit(startIndex)->getSourceRange());
634          }
635          return false;
636        }
637      }
638      int maxElements;
639      if (DeclType->isIncompleteArrayType()) {
640        // FIXME: use a proper constant
641        maxElements = 0x7FFFFFFF;
642      } else if (const VariableArrayType *VAT =
643                                DeclType->getAsVariableArrayType()) {
644        // Check for VLAs; in standard C it would be possible to check this
645        // earlier, but I don't know where clang accepts VLAs (gcc accepts
646        // them in all sorts of strange places).
647        Diag(VAT->getSizeExpr()->getLocStart(),
648             diag::err_variable_object_no_init,
649             VAT->getSizeExpr()->getSourceRange());
650        hadError = true;
651        maxElements = 0x7FFFFFFF;
652      } else {
653        const ConstantArrayType *CAT = DeclType->getAsConstantArrayType();
654        maxElements = static_cast<int>(CAT->getSize().getZExtValue());
655      }
656      QualType elementType = DeclType->getAsArrayType()->getElementType();
657      int numElements = 0;
658      for (int i = 0; i < maxElements; ++i, ++numElements) {
659        // Don't attempt to go past the end of the init list
660        if (startIndex >= IList->getNumInits())
661          break;
662        Expr* expr = IList->getInit(startIndex);
663        if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) {
664          unsigned newIndex = 0;
665          hadError |= CheckInitializerListTypes(SubInitList, elementType,
666                                                true, newIndex);
667          ++startIndex;
668        } else {
669          hadError |= CheckInitializerListTypes(IList, elementType,
670                                                false, startIndex);
671        }
672      }
673      if (DeclType->isIncompleteArrayType()) {
674        // If this is an incomplete array type, the actual type needs to
675        // be calculated here
676        if (numElements == 0) {
677          // Sizing an array implicitly to zero is not allowed
678          // (It could in theory be allowed, but it doesn't really matter.)
679          Diag(IList->getLocStart(),
680               diag::err_at_least_one_initializer_needed_to_size_array);
681          hadError = true;
682        } else {
683          llvm::APSInt ConstVal(32);
684          ConstVal = numElements;
685          DeclType = Context.getConstantArrayType(elementType, ConstVal,
686                                                  ArrayType::Normal, 0);
687        }
688      }
689    } else {
690      assert(0 && "Aggregate that isn't a function or array?!");
691    }
692  } else {
693    // In C, all types are either scalars or aggregates, but
694    // additional handling is needed here for C++ (and possibly others?).
695    assert(0 && "Unsupported initializer type");
696  }
697
698  // If this init list is a base list, we set the type; an initializer doesn't
699  // fundamentally have a type, but this makes the ASTs a bit easier to read
700  if (topLevel)
701    IList->setType(DeclType);
702
703  if (topLevel && startIndex < IList->getNumInits()) {
704    // We have leftover initializers; warn
705    Diag(IList->getInit(startIndex)->getLocStart(),
706         diag::warn_excess_initializers,
707         IList->getInit(startIndex)->getSourceRange());
708  }
709  return hadError;
710}
711
712bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType) {
713  // C99 6.7.8p3: The type of the entity to be initialized shall be an array
714  // of unknown size ("[]") or an object type that is not a variable array type.
715  if (const VariableArrayType *VAT = DeclType->getAsVariableArrayType())
716    return Diag(VAT->getSizeExpr()->getLocStart(),
717                diag::err_variable_object_no_init,
718                VAT->getSizeExpr()->getSourceRange());
719
720  InitListExpr *InitList = dyn_cast<InitListExpr>(Init);
721  if (!InitList) {
722    // FIXME: Handle wide strings
723    if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType))
724      return CheckStringLiteralInit(strLiteral, DeclType);
725
726    if (DeclType->isArrayType())
727      return Diag(Init->getLocStart(),
728                  diag::err_array_init_list_required,
729                  Init->getSourceRange());
730
731    return CheckSingleInitializer(Init, DeclType);
732  }
733  unsigned newIndex = 0;
734  return CheckInitializerListTypes(InitList, DeclType, true, newIndex);
735}
736
737Sema::DeclTy *
738Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) {
739  ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl);
740  IdentifierInfo *II = D.getIdentifier();
741
742  // All of these full declarators require an identifier.  If it doesn't have
743  // one, the ParsedFreeStandingDeclSpec action should be used.
744  if (II == 0) {
745    Diag(D.getDeclSpec().getSourceRange().getBegin(),
746         diag::err_declarator_need_ident,
747         D.getDeclSpec().getSourceRange(), D.getSourceRange());
748    return 0;
749  }
750
751  // The scope passed in may not be a decl scope.  Zip up the scope tree until
752  // we find one that is.
753  while ((S->getFlags() & Scope::DeclScope) == 0)
754    S = S->getParent();
755
756  // See if this is a redefinition of a variable in the same scope.
757  Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S);
758  ScopedDecl *New;
759  bool InvalidDecl = false;
760
761  // In C++, the previous declaration we find might be a tag type
762  // (class or enum). In this case, the new declaration will hide the
763  // tag type.
764  if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag)
765    PrevDecl = 0;
766
767  QualType R = GetTypeForDeclarator(D, S);
768  assert(!R.isNull() && "GetTypeForDeclarator() returned null type");
769
770  if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
771    TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator);
772    if (!NewTD) return 0;
773
774    // Handle attributes prior to checking for duplicates in MergeVarDecl
775    HandleDeclAttributes(NewTD, D.getDeclSpec().getAttributes(),
776                         D.getAttributes());
777    // Merge the decl with the existing one if appropriate. If the decl is
778    // in an outer scope, it isn't the same thing.
779    if (PrevDecl && S->isDeclScope(PrevDecl)) {
780      NewTD = MergeTypeDefDecl(NewTD, PrevDecl);
781      if (NewTD == 0) return 0;
782    }
783    New = NewTD;
784    if (S->getParent() == 0) {
785      // C99 6.7.7p2: If a typedef name specifies a variably modified type
786      // then it shall have block scope.
787      if (NewTD->getUnderlyingType()->isVariablyModifiedType()) {
788        // FIXME: Diagnostic needs to be fixed.
789        Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla);
790        InvalidDecl = true;
791      }
792    }
793  } else if (R.getTypePtr()->isFunctionType()) {
794    FunctionDecl::StorageClass SC = FunctionDecl::None;
795    switch (D.getDeclSpec().getStorageClassSpec()) {
796      default: assert(0 && "Unknown storage class!");
797      case DeclSpec::SCS_auto:
798      case DeclSpec::SCS_register:
799        Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func,
800             R.getAsString());
801        InvalidDecl = true;
802        break;
803      case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break;
804      case DeclSpec::SCS_extern:      SC = FunctionDecl::Extern; break;
805      case DeclSpec::SCS_static:      SC = FunctionDecl::Static; break;
806      case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break;
807    }
808
809    bool isInline = D.getDeclSpec().isInlineSpecified();
810    FunctionDecl *NewFD = FunctionDecl::Create(Context, CurContext,
811                                               D.getIdentifierLoc(),
812                                               II, R, SC, isInline,
813                                               LastDeclarator);
814    // Handle attributes.
815    HandleDeclAttributes(NewFD, D.getDeclSpec().getAttributes(),
816                         D.getAttributes());
817
818    // Copy the parameter declarations from the declarator D to
819    // the function declaration NewFD, if they are available.
820    if (D.getNumTypeObjects() > 0 &&
821        D.getTypeObject(0).Fun.hasPrototype) {
822      DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
823
824      // Create Decl objects for each parameter, adding them to the
825      // FunctionDecl.
826      llvm::SmallVector<ParmVarDecl*, 16> Params;
827
828      // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs
829      // function that takes no arguments, not a function that takes a
830      // single void argument.
831      if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 &&
832          FTI.ArgInfo[0].Param &&
833          !((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType().getCVRQualifiers() &&
834          ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) {
835        // empty arg list, don't push any params.
836        ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param;
837
838        // In C++, the empty parameter-type-list must be spelled "void"; a
839        // typedef of void is not permitted.
840        if (getLangOptions().CPlusPlus &&
841            Param->getType() != Context.VoidTy) {
842          Diag(Param->getLocation(), diag::ext_param_typedef_of_void);
843        }
844
845      } else {
846        for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i)
847          Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param);
848      }
849
850      NewFD->setParams(&Params[0], Params.size());
851    }
852
853    // Merge the decl with the existing one if appropriate. Since C functions
854    // are in a flat namespace, make sure we consider decls in outer scopes.
855    if (PrevDecl) {
856      bool Redeclaration = false;
857      NewFD = MergeFunctionDecl(NewFD, PrevDecl, Redeclaration);
858      if (NewFD == 0) return 0;
859      if (Redeclaration) {
860        // Note that the new declaration is a redeclaration of the
861        // older declaration. Then return the older declaration: the
862        // new one is only kept within the set of previous
863        // declarations for this function.
864        FunctionDecl *OldFD = (FunctionDecl *)PrevDecl;
865        OldFD->AddRedeclaration(NewFD);
866        return OldFD;
867      }
868    }
869    New = NewFD;
870
871    // In C++, check default arguments now that we have merged decls.
872    if (getLangOptions().CPlusPlus)
873      CheckCXXDefaultArguments(NewFD);
874  } else {
875    if (R.getTypePtr()->isObjCInterfaceType()) {
876      Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object,
877           D.getIdentifier()->getName());
878      InvalidDecl = true;
879    }
880
881    VarDecl *NewVD;
882    VarDecl::StorageClass SC;
883    switch (D.getDeclSpec().getStorageClassSpec()) {
884    default: assert(0 && "Unknown storage class!");
885    case DeclSpec::SCS_unspecified:    SC = VarDecl::None; break;
886    case DeclSpec::SCS_extern:         SC = VarDecl::Extern; break;
887    case DeclSpec::SCS_static:         SC = VarDecl::Static; break;
888    case DeclSpec::SCS_auto:           SC = VarDecl::Auto; break;
889    case DeclSpec::SCS_register:       SC = VarDecl::Register; break;
890    case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break;
891    }
892    if (S->getParent() == 0) {
893      // C99 6.9p2: The storage-class specifiers auto and register shall not
894      // appear in the declaration specifiers in an external declaration.
895      if (SC == VarDecl::Auto || SC == VarDecl::Register) {
896        Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope,
897             R.getAsString());
898        InvalidDecl = true;
899      }
900      NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(),
901                              II, R, SC, LastDeclarator);
902    } else {
903      NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(),
904                              II, R, SC, LastDeclarator);
905    }
906    // Handle attributes prior to checking for duplicates in MergeVarDecl
907    HandleDeclAttributes(NewVD, D.getDeclSpec().getAttributes(),
908                         D.getAttributes());
909
910    // Emit an error if an address space was applied to decl with local storage.
911    // This includes arrays of objects with address space qualifiers, but not
912    // automatic variables that point to other address spaces.
913    // ISO/IEC TR 18037 S5.1.2
914    if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) {
915      Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl);
916      InvalidDecl = true;
917    }
918    // Merge the decl with the existing one if appropriate. If the decl is
919    // in an outer scope, it isn't the same thing.
920    if (PrevDecl && S->isDeclScope(PrevDecl)) {
921      NewVD = MergeVarDecl(NewVD, PrevDecl);
922      if (NewVD == 0) return 0;
923    }
924    New = NewVD;
925  }
926
927  // If this has an identifier, add it to the scope stack.
928  if (II)
929    PushOnScopeChains(New, S);
930  // If any semantic error occurred, mark the decl as invalid.
931  if (D.getInvalidType() || InvalidDecl)
932    New->setInvalidDecl();
933
934  return New;
935}
936
937bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) {
938  SourceLocation loc;
939  // FIXME: Remove the isReference check and handle assignment to a reference.
940  if (!DclT->isReferenceType() && !Init->isConstantExpr(Context, &loc)) {
941    assert(loc.isValid() && "isConstantExpr didn't return a loc!");
942    Diag(loc, diag::err_init_element_not_constant, Init->getSourceRange());
943    return true;
944  }
945  return false;
946}
947
948void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) {
949  Decl *RealDecl = static_cast<Decl *>(dcl);
950  Expr *Init = static_cast<Expr *>(init);
951  assert(Init && "missing initializer");
952
953  // If there is no declaration, there was an error parsing it.  Just ignore
954  // the initializer.
955  if (RealDecl == 0) {
956    delete Init;
957    return;
958  }
959
960  VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl);
961  if (!VDecl) {
962    Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(),
963         diag::err_illegal_initializer);
964    RealDecl->setInvalidDecl();
965    return;
966  }
967  // Get the decls type and save a reference for later, since
968  // CheckInitializerTypes may change it.
969  QualType DclT = VDecl->getType(), SavT = DclT;
970  if (VDecl->isBlockVarDecl()) {
971    VarDecl::StorageClass SC = VDecl->getStorageClass();
972    if (SC == VarDecl::Extern) { // C99 6.7.8p5
973      Diag(VDecl->getLocation(), diag::err_block_extern_cant_init);
974      VDecl->setInvalidDecl();
975    } else if (!VDecl->isInvalidDecl()) {
976      if (CheckInitializerTypes(Init, DclT))
977        VDecl->setInvalidDecl();
978      if (SC == VarDecl::Static) // C99 6.7.8p4.
979        CheckForConstantInitializer(Init, DclT);
980    }
981  } else if (VDecl->isFileVarDecl()) {
982    if (VDecl->getStorageClass() == VarDecl::Extern)
983      Diag(VDecl->getLocation(), diag::warn_extern_init);
984    if (!VDecl->isInvalidDecl())
985      if (CheckInitializerTypes(Init, DclT))
986        VDecl->setInvalidDecl();
987
988    // C99 6.7.8p4. All file scoped initializers need to be constant.
989    CheckForConstantInitializer(Init, DclT);
990  }
991  // If the type changed, it means we had an incomplete type that was
992  // completed by the initializer. For example:
993  //   int ary[] = { 1, 3, 5 };
994  // "ary" transitions from a VariableArrayType to a ConstantArrayType.
995  if (!VDecl->isInvalidDecl() && (DclT != SavT)) {
996    VDecl->setType(DclT);
997    Init->setType(DclT);
998  }
999
1000  // Attach the initializer to the decl.
1001  VDecl->setInit(Init);
1002  return;
1003}
1004
1005/// The declarators are chained together backwards, reverse the list.
1006Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) {
1007  // Often we have single declarators, handle them quickly.
1008  Decl *GroupDecl = static_cast<Decl*>(group);
1009  if (GroupDecl == 0)
1010    return 0;
1011
1012  ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl);
1013  ScopedDecl *NewGroup = 0;
1014  if (Group->getNextDeclarator() == 0)
1015    NewGroup = Group;
1016  else { // reverse the list.
1017    while (Group) {
1018      ScopedDecl *Next = Group->getNextDeclarator();
1019      Group->setNextDeclarator(NewGroup);
1020      NewGroup = Group;
1021      Group = Next;
1022    }
1023  }
1024  // Perform semantic analysis that depends on having fully processed both
1025  // the declarator and initializer.
1026  for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) {
1027    VarDecl *IDecl = dyn_cast<VarDecl>(ID);
1028    if (!IDecl)
1029      continue;
1030    QualType T = IDecl->getType();
1031
1032    // C99 6.7.5.2p2: If an identifier is declared to be an object with
1033    // static storage duration, it shall not have a variable length array.
1034    if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) &&
1035        IDecl->getStorageClass() == VarDecl::Static) {
1036      if (T->getAsVariableArrayType()) {
1037        Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla);
1038        IDecl->setInvalidDecl();
1039      }
1040    }
1041    // Block scope. C99 6.7p7: If an identifier for an object is declared with
1042    // no linkage (C99 6.2.2p6), the type for the object shall be complete...
1043    if (IDecl->isBlockVarDecl() &&
1044        IDecl->getStorageClass() != VarDecl::Extern) {
1045      if (T->isIncompleteType() && !IDecl->isInvalidDecl()) {
1046        Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type,
1047             T.getAsString());
1048        IDecl->setInvalidDecl();
1049      }
1050    }
1051    // File scope. C99 6.9.2p2: A declaration of an identifier for and
1052    // object that has file scope without an initializer, and without a
1053    // storage-class specifier or with the storage-class specifier "static",
1054    // constitutes a tentative definition. Note: A tentative definition with
1055    // external linkage is valid (C99 6.2.2p5).
1056    if (IDecl && !IDecl->getInit() &&
1057        (IDecl->getStorageClass() == VarDecl::Static ||
1058         IDecl->getStorageClass() == VarDecl::None)) {
1059      if (T->isIncompleteArrayType()) {
1060        // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete
1061        // array to be completed. Don't issue a diagnostic.
1062      } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) {
1063        // C99 6.9.2p3: If the declaration of an identifier for an object is
1064        // a tentative definition and has internal linkage (C99 6.2.2p3), the
1065        // declared type shall not be an incomplete type.
1066        Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type,
1067             T.getAsString());
1068        IDecl->setInvalidDecl();
1069      }
1070    }
1071  }
1072  return NewGroup;
1073}
1074
1075/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator()
1076/// to introduce parameters into function prototype scope.
1077Sema::DeclTy *
1078Sema::ActOnParamDeclarator(Scope *S, Declarator &D) {
1079  DeclSpec &DS = D.getDeclSpec();
1080
1081  // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'.
1082  if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
1083      DS.getStorageClassSpec() != DeclSpec::SCS_register) {
1084    Diag(DS.getStorageClassSpecLoc(),
1085         diag::err_invalid_storage_class_in_func_decl);
1086    DS.ClearStorageClassSpecs();
1087  }
1088  if (DS.isThreadSpecified()) {
1089    Diag(DS.getThreadSpecLoc(),
1090         diag::err_invalid_storage_class_in_func_decl);
1091    DS.ClearStorageClassSpecs();
1092  }
1093
1094
1095  // In this context, we *do not* check D.getInvalidType(). If the declarator
1096  // type was invalid, GetTypeForDeclarator() still returns a "valid" type,
1097  // though it will not reflect the user specified type.
1098  QualType parmDeclType = GetTypeForDeclarator(D, S);
1099
1100  assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type");
1101
1102  // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
1103  // Can this happen for params?  We already checked that they don't conflict
1104  // among each other.  Here they can only shadow globals, which is ok.
1105  IdentifierInfo *II = D.getIdentifier();
1106  if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) {
1107    if (S->isDeclScope(PrevDecl)) {
1108      Diag(D.getIdentifierLoc(), diag::err_param_redefinition,
1109           dyn_cast<NamedDecl>(PrevDecl)->getName());
1110
1111      // Recover by removing the name
1112      II = 0;
1113      D.SetIdentifier(0, D.getIdentifierLoc());
1114    }
1115  }
1116
1117  // Perform the default function/array conversion (C99 6.7.5.3p[7,8]).
1118  // Doing the promotion here has a win and a loss. The win is the type for
1119  // both Decl's and DeclRefExpr's will match (a convenient invariant for the
1120  // code generator). The loss is the orginal type isn't preserved. For example:
1121  //
1122  // void func(int parmvardecl[5]) { // convert "int [5]" to "int *"
1123  //    int blockvardecl[5];
1124  //    sizeof(parmvardecl);  // size == 4
1125  //    sizeof(blockvardecl); // size == 20
1126  // }
1127  //
1128  // For expressions, all implicit conversions are captured using the
1129  // ImplicitCastExpr AST node (we have no such mechanism for Decl's).
1130  //
1131  // FIXME: If a source translation tool needs to see the original type, then
1132  // we need to consider storing both types (in ParmVarDecl)...
1133  //
1134  if (parmDeclType->isArrayType()) {
1135    // int x[restrict 4] ->  int *restrict
1136    parmDeclType = Context.getArrayDecayedType(parmDeclType);
1137  } else if (parmDeclType->isFunctionType())
1138    parmDeclType = Context.getPointerType(parmDeclType);
1139
1140  ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext,
1141                                         D.getIdentifierLoc(), II,
1142                                         parmDeclType, VarDecl::None,
1143                                         0, 0);
1144
1145  if (D.getInvalidType())
1146    New->setInvalidDecl();
1147
1148  if (II)
1149    PushOnScopeChains(New, S);
1150
1151  HandleDeclAttributes(New, D.getAttributes(), 0);
1152  return New;
1153
1154}
1155
1156Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) {
1157  assert(CurFunctionDecl == 0 && "Function parsing confused");
1158  assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function &&
1159         "Not a function declarator!");
1160  DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
1161
1162  // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared'
1163  // for a K&R function.
1164  if (!FTI.hasPrototype) {
1165    for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) {
1166      if (FTI.ArgInfo[i].Param == 0) {
1167        Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared,
1168             FTI.ArgInfo[i].Ident->getName());
1169        // Implicitly declare the argument as type 'int' for lack of a better
1170        // type.
1171        DeclSpec DS;
1172        const char* PrevSpec; // unused
1173        DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc,
1174                           PrevSpec);
1175        Declarator ParamD(DS, Declarator::KNRTypeListContext);
1176        ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc);
1177        FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD);
1178      }
1179    }
1180
1181    // Since this is a function definition, act as though we have information
1182    // about the arguments.
1183    if (FTI.NumArgs)
1184      FTI.hasPrototype = true;
1185  } else {
1186    // FIXME: Diagnose arguments without names in C.
1187  }
1188
1189  Scope *GlobalScope = FnBodyScope->getParent();
1190
1191  // See if this is a redefinition.
1192  Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary,
1193                             GlobalScope);
1194  if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(PrevDcl)) {
1195    const FunctionDecl *Definition;
1196    if (FD->getBody(Definition)) {
1197      Diag(D.getIdentifierLoc(), diag::err_redefinition,
1198           D.getIdentifier()->getName());
1199      Diag(Definition->getLocation(), diag::err_previous_definition);
1200    }
1201  }
1202  Decl *decl = static_cast<Decl*>(ActOnDeclarator(GlobalScope, D, 0));
1203  FunctionDecl *FD = cast<FunctionDecl>(decl);
1204  CurFunctionDecl = FD;
1205  PushDeclContext(FD);
1206
1207  // Check the validity of our function parameters
1208  CheckParmsForFunctionDef(FD);
1209
1210  // Introduce our parameters into the function scope
1211  for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) {
1212    ParmVarDecl *Param = FD->getParamDecl(p);
1213    // If this has an identifier, add it to the scope stack.
1214    if (Param->getIdentifier())
1215      PushOnScopeChains(Param, FnBodyScope);
1216  }
1217
1218  return FD;
1219}
1220
1221Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) {
1222  Decl *dcl = static_cast<Decl *>(D);
1223  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(dcl)) {
1224    FD->setBody((Stmt*)Body);
1225    assert(FD == CurFunctionDecl && "Function parsing confused");
1226    CurFunctionDecl = 0;
1227  } else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(dcl)) {
1228    MD->setBody((Stmt*)Body);
1229    CurMethodDecl = 0;
1230  }
1231  PopDeclContext();
1232  // Verify and clean out per-function state.
1233
1234  // Check goto/label use.
1235  for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator
1236       I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) {
1237    // Verify that we have no forward references left.  If so, there was a goto
1238    // or address of a label taken, but no definition of it.  Label fwd
1239    // definitions are indicated with a null substmt.
1240    if (I->second->getSubStmt() == 0) {
1241      LabelStmt *L = I->second;
1242      // Emit error.
1243      Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName());
1244
1245      // At this point, we have gotos that use the bogus label.  Stitch it into
1246      // the function body so that they aren't leaked and that the AST is well
1247      // formed.
1248      if (Body) {
1249        L->setSubStmt(new NullStmt(L->getIdentLoc()));
1250        cast<CompoundStmt>((Stmt*)Body)->push_back(L);
1251      } else {
1252        // The whole function wasn't parsed correctly, just delete this.
1253        delete L;
1254      }
1255    }
1256  }
1257  LabelMap.clear();
1258
1259  return D;
1260}
1261
1262/// ImplicitlyDefineFunction - An undeclared identifier was used in a function
1263/// call, forming a call to an implicitly defined function (per C99 6.5.1p2).
1264ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc,
1265                                           IdentifierInfo &II, Scope *S) {
1266  if (getLangOptions().C99)  // Extension in C99.
1267    Diag(Loc, diag::ext_implicit_function_decl, II.getName());
1268  else  // Legal in C90, but warn about it.
1269    Diag(Loc, diag::warn_implicit_function_decl, II.getName());
1270
1271  // FIXME: handle stuff like:
1272  // void foo() { extern float X(); }
1273  // void bar() { X(); }  <-- implicit decl for X in another scope.
1274
1275  // Set a Declarator for the implicit definition: int foo();
1276  const char *Dummy;
1277  DeclSpec DS;
1278  bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy);
1279  Error = Error; // Silence warning.
1280  assert(!Error && "Error setting up implicit decl!");
1281  Declarator D(DS, Declarator::BlockContext);
1282  D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc));
1283  D.SetIdentifier(&II, Loc);
1284
1285  // Find translation-unit scope to insert this function into.
1286  if (Scope *FnS = S->getFnParent())
1287    S = FnS->getParent();   // Skip all scopes in a function at once.
1288  while (S->getParent())
1289    S = S->getParent();
1290
1291  FunctionDecl *FD =
1292    dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(S, D, 0)));
1293  FD->setImplicit();
1294  return FD;
1295}
1296
1297
1298TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T,
1299                                    ScopedDecl *LastDeclarator) {
1300  assert(D.getIdentifier() && "Wrong callback for declspec without declarator");
1301  assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
1302
1303  // Scope manipulation handled by caller.
1304  TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext,
1305                                           D.getIdentifierLoc(),
1306                                           D.getIdentifier(),
1307                                           T, LastDeclarator);
1308  if (D.getInvalidType())
1309    NewTD->setInvalidDecl();
1310  return NewTD;
1311}
1312
1313/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'.  In the
1314/// former case, Name will be non-null.  In the later case, Name will be null.
1315/// TagType indicates what kind of tag this is. TK indicates whether this is a
1316/// reference/declaration/definition of a tag.
1317Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK,
1318                             SourceLocation KWLoc, IdentifierInfo *Name,
1319                             SourceLocation NameLoc, AttributeList *Attr) {
1320  // If this is a use of an existing tag, it must have a name.
1321  assert((Name != 0 || TK == TK_Definition) &&
1322         "Nameless record must be a definition!");
1323
1324  Decl::Kind Kind;
1325  switch (TagType) {
1326  default: assert(0 && "Unknown tag type!");
1327  case DeclSpec::TST_struct: Kind = Decl::Struct; break;
1328  case DeclSpec::TST_union:  Kind = Decl::Union; break;
1329  case DeclSpec::TST_class:  Kind = Decl::Class; break;
1330  case DeclSpec::TST_enum:   Kind = Decl::Enum; break;
1331  }
1332
1333  // If this is a named struct, check to see if there was a previous forward
1334  // declaration or definition.
1335  if (TagDecl *PrevDecl =
1336          dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag, S))) {
1337
1338    // If this is a use of a previous tag, or if the tag is already declared in
1339    // the same scope (so that the definition/declaration completes or
1340    // rementions the tag), reuse the decl.
1341    if (TK == TK_Reference || S->isDeclScope(PrevDecl)) {
1342      // Make sure that this wasn't declared as an enum and now used as a struct
1343      // or something similar.
1344      if (PrevDecl->getKind() != Kind) {
1345        Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName());
1346        Diag(PrevDecl->getLocation(), diag::err_previous_use);
1347      }
1348
1349      // If this is a use or a forward declaration, we're good.
1350      if (TK != TK_Definition)
1351        return PrevDecl;
1352
1353      // Diagnose attempts to redefine a tag.
1354      if (PrevDecl->isDefinition()) {
1355        Diag(NameLoc, diag::err_redefinition, Name->getName());
1356        Diag(PrevDecl->getLocation(), diag::err_previous_definition);
1357        // If this is a redefinition, recover by making this struct be
1358        // anonymous, which will make any later references get the previous
1359        // definition.
1360        Name = 0;
1361      } else {
1362        // Okay, this is definition of a previously declared or referenced tag.
1363        // Move the location of the decl to be the definition site.
1364        PrevDecl->setLocation(NameLoc);
1365        return PrevDecl;
1366      }
1367    }
1368    // If we get here, this is a definition of a new struct type in a nested
1369    // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new
1370    // type.
1371  }
1372
1373  // If there is an identifier, use the location of the identifier as the
1374  // location of the decl, otherwise use the location of the struct/union
1375  // keyword.
1376  SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
1377
1378  // Otherwise, if this is the first time we've seen this tag, create the decl.
1379  TagDecl *New;
1380  switch (Kind) {
1381  default: assert(0 && "Unknown tag kind!");
1382  case Decl::Enum:
1383    // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
1384    // enum X { A, B, C } D;    D should chain to X.
1385    New = EnumDecl::Create(Context, CurContext, Loc, Name, 0);
1386    // If this is an undefined enum, warn.
1387    if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum);
1388    break;
1389  case Decl::Union:
1390  case Decl::Struct:
1391  case Decl::Class:
1392    // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
1393    // struct X { int A; } D;    D should chain to X.
1394    New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0);
1395    break;
1396  }
1397
1398  // If this has an identifier, add it to the scope stack.
1399  if (Name) {
1400    // The scope passed in may not be a decl scope.  Zip up the scope tree until
1401    // we find one that is.
1402    while ((S->getFlags() & Scope::DeclScope) == 0)
1403      S = S->getParent();
1404
1405    // Add it to the decl chain.
1406    PushOnScopeChains(New, S);
1407  }
1408
1409  HandleDeclAttributes(New, Attr, 0);
1410  return New;
1411}
1412
1413/// ActOnField - Each field of a struct/union/class is passed into this in order
1414/// to create a FieldDecl object for it.
1415Sema::DeclTy *Sema::ActOnField(Scope *S,
1416                               SourceLocation DeclStart,
1417                               Declarator &D, ExprTy *BitfieldWidth) {
1418  IdentifierInfo *II = D.getIdentifier();
1419  Expr *BitWidth = (Expr*)BitfieldWidth;
1420  SourceLocation Loc = DeclStart;
1421  if (II) Loc = D.getIdentifierLoc();
1422
1423  // FIXME: Unnamed fields can be handled in various different ways, for
1424  // example, unnamed unions inject all members into the struct namespace!
1425
1426
1427  if (BitWidth) {
1428    // TODO: Validate.
1429    //printf("WARNING: BITFIELDS IGNORED!\n");
1430
1431    // 6.7.2.1p3
1432    // 6.7.2.1p4
1433
1434  } else {
1435    // Not a bitfield.
1436
1437    // validate II.
1438
1439  }
1440
1441  QualType T = GetTypeForDeclarator(D, S);
1442  assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
1443  bool InvalidDecl = false;
1444
1445  // C99 6.7.2.1p8: A member of a structure or union may have any type other
1446  // than a variably modified type.
1447  if (T->isVariablyModifiedType()) {
1448    // FIXME: This diagnostic needs work
1449    Diag(Loc, diag::err_typecheck_illegal_vla, Loc);
1450    InvalidDecl = true;
1451  }
1452  // FIXME: Chain fielddecls together.
1453  FieldDecl *NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth);
1454
1455  HandleDeclAttributes(NewFD, D.getDeclSpec().getAttributes(),
1456                       D.getAttributes());
1457
1458  if (D.getInvalidType() || InvalidDecl)
1459    NewFD->setInvalidDecl();
1460  return NewFD;
1461}
1462
1463/// TranslateIvarVisibility - Translate visibility from a token ID to an
1464///  AST enum value.
1465static ObjCIvarDecl::AccessControl
1466TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) {
1467  switch (ivarVisibility) {
1468    case tok::objc_private: return ObjCIvarDecl::Private;
1469    case tok::objc_public: return ObjCIvarDecl::Public;
1470    case tok::objc_protected: return ObjCIvarDecl::Protected;
1471    case tok::objc_package: return ObjCIvarDecl::Package;
1472    default: assert(false && "Unknown visitibility kind");
1473  }
1474}
1475
1476/// ActOnIvar - Each ivar field of an objective-c class is passed into this
1477/// in order to create an IvarDecl object for it.
1478Sema::DeclTy *Sema::ActOnIvar(Scope *S,
1479                              SourceLocation DeclStart,
1480                              Declarator &D, ExprTy *BitfieldWidth,
1481                              tok::ObjCKeywordKind Visibility) {
1482  IdentifierInfo *II = D.getIdentifier();
1483  Expr *BitWidth = (Expr*)BitfieldWidth;
1484  SourceLocation Loc = DeclStart;
1485  if (II) Loc = D.getIdentifierLoc();
1486
1487  // FIXME: Unnamed fields can be handled in various different ways, for
1488  // example, unnamed unions inject all members into the struct namespace!
1489
1490
1491  if (BitWidth) {
1492    // TODO: Validate.
1493    //printf("WARNING: BITFIELDS IGNORED!\n");
1494
1495    // 6.7.2.1p3
1496    // 6.7.2.1p4
1497
1498  } else {
1499    // Not a bitfield.
1500
1501    // validate II.
1502
1503  }
1504
1505  QualType T = GetTypeForDeclarator(D, S);
1506  assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
1507  bool InvalidDecl = false;
1508
1509  // C99 6.7.2.1p8: A member of a structure or union may have any type other
1510  // than a variably modified type.
1511  if (T->isVariablyModifiedType()) {
1512    // FIXME: This diagnostic needs work
1513    Diag(Loc, diag::err_typecheck_illegal_vla, Loc);
1514    InvalidDecl = true;
1515  }
1516
1517  ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T);
1518
1519  HandleDeclAttributes(NewID, D.getDeclSpec().getAttributes(),
1520                       D.getAttributes());
1521
1522  if (D.getInvalidType() || InvalidDecl)
1523    NewID->setInvalidDecl();
1524  // If we have visibility info, make sure the AST is set accordingly.
1525  if (Visibility != tok::objc_not_keyword)
1526    NewID->setAccessControl(TranslateIvarVisibility(Visibility));
1527  return NewID;
1528}
1529
1530void Sema::ActOnFields(Scope* S,
1531                       SourceLocation RecLoc, DeclTy *RecDecl,
1532                       DeclTy **Fields, unsigned NumFields,
1533                       SourceLocation LBrac, SourceLocation RBrac) {
1534  Decl *EnclosingDecl = static_cast<Decl*>(RecDecl);
1535  assert(EnclosingDecl && "missing record or interface decl");
1536  RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl);
1537
1538  if (Record && Record->isDefinition()) {
1539    // Diagnose code like:
1540    //     struct S { struct S {} X; };
1541    // We discover this when we complete the outer S.  Reject and ignore the
1542    // outer S.
1543    Diag(Record->getLocation(), diag::err_nested_redefinition,
1544         Record->getKindName());
1545    Diag(RecLoc, diag::err_previous_definition);
1546    Record->setInvalidDecl();
1547    return;
1548  }
1549  // Verify that all the fields are okay.
1550  unsigned NumNamedMembers = 0;
1551  llvm::SmallVector<FieldDecl*, 32> RecFields;
1552  llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs;
1553
1554  for (unsigned i = 0; i != NumFields; ++i) {
1555
1556    FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i]));
1557    assert(FD && "missing field decl");
1558
1559    // Remember all fields.
1560    RecFields.push_back(FD);
1561
1562    // Get the type for the field.
1563    Type *FDTy = FD->getType().getTypePtr();
1564
1565    // C99 6.7.2.1p2 - A field may not be a function type.
1566    if (FDTy->isFunctionType()) {
1567      Diag(FD->getLocation(), diag::err_field_declared_as_function,
1568           FD->getName());
1569      FD->setInvalidDecl();
1570      EnclosingDecl->setInvalidDecl();
1571      continue;
1572    }
1573    // C99 6.7.2.1p2 - A field may not be an incomplete type except...
1574    if (FDTy->isIncompleteType()) {
1575      if (!Record) {  // Incomplete ivar type is always an error.
1576        Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName());
1577        FD->setInvalidDecl();
1578        EnclosingDecl->setInvalidDecl();
1579        continue;
1580      }
1581      if (i != NumFields-1 ||                   // ... that the last member ...
1582          Record->getKind() != Decl::Struct ||  // ... of a structure ...
1583          !FDTy->isArrayType()) {         //... may have incomplete array type.
1584        Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName());
1585        FD->setInvalidDecl();
1586        EnclosingDecl->setInvalidDecl();
1587        continue;
1588      }
1589      if (NumNamedMembers < 1) {  //... must have more than named member ...
1590        Diag(FD->getLocation(), diag::err_flexible_array_empty_struct,
1591             FD->getName());
1592        FD->setInvalidDecl();
1593        EnclosingDecl->setInvalidDecl();
1594        continue;
1595      }
1596      // Okay, we have a legal flexible array member at the end of the struct.
1597      if (Record)
1598        Record->setHasFlexibleArrayMember(true);
1599    }
1600    /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the
1601    /// field of another structure or the element of an array.
1602    if (const RecordType *FDTTy = FDTy->getAsRecordType()) {
1603      if (FDTTy->getDecl()->hasFlexibleArrayMember()) {
1604        // If this is a member of a union, then entire union becomes "flexible".
1605        if (Record && Record->getKind() == Decl::Union) {
1606          Record->setHasFlexibleArrayMember(true);
1607        } else {
1608          // If this is a struct/class and this is not the last element, reject
1609          // it.  Note that GCC supports variable sized arrays in the middle of
1610          // structures.
1611          if (i != NumFields-1) {
1612            Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct,
1613                 FD->getName());
1614            FD->setInvalidDecl();
1615            EnclosingDecl->setInvalidDecl();
1616            continue;
1617          }
1618          // We support flexible arrays at the end of structs in other structs
1619          // as an extension.
1620          Diag(FD->getLocation(), diag::ext_flexible_array_in_struct,
1621               FD->getName());
1622          if (Record)
1623            Record->setHasFlexibleArrayMember(true);
1624        }
1625      }
1626    }
1627    /// A field cannot be an Objective-c object
1628    if (FDTy->isObjCInterfaceType()) {
1629      Diag(FD->getLocation(), diag::err_statically_allocated_object,
1630           FD->getName());
1631      FD->setInvalidDecl();
1632      EnclosingDecl->setInvalidDecl();
1633      continue;
1634    }
1635    // Keep track of the number of named members.
1636    if (IdentifierInfo *II = FD->getIdentifier()) {
1637      // Detect duplicate member names.
1638      if (!FieldIDs.insert(II)) {
1639        Diag(FD->getLocation(), diag::err_duplicate_member, II->getName());
1640        // Find the previous decl.
1641        SourceLocation PrevLoc;
1642        for (unsigned i = 0, e = RecFields.size(); ; ++i) {
1643          assert(i != e && "Didn't find previous def!");
1644          if (RecFields[i]->getIdentifier() == II) {
1645            PrevLoc = RecFields[i]->getLocation();
1646            break;
1647          }
1648        }
1649        Diag(PrevLoc, diag::err_previous_definition);
1650        FD->setInvalidDecl();
1651        EnclosingDecl->setInvalidDecl();
1652        continue;
1653      }
1654      ++NumNamedMembers;
1655    }
1656  }
1657
1658  // Okay, we successfully defined 'Record'.
1659  if (Record) {
1660    Record->defineBody(&RecFields[0], RecFields.size());
1661    Consumer.HandleTagDeclDefinition(Record);
1662  } else {
1663    ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]);
1664    if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl))
1665      ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac);
1666    else if (ObjCImplementationDecl *IMPDecl =
1667               dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) {
1668      assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl");
1669      IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size());
1670      CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac);
1671    }
1672  }
1673}
1674
1675Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl,
1676                                      DeclTy *lastEnumConst,
1677                                      SourceLocation IdLoc, IdentifierInfo *Id,
1678                                      SourceLocation EqualLoc, ExprTy *val) {
1679  EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl));
1680  EnumConstantDecl *LastEnumConst =
1681    cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst));
1682  Expr *Val = static_cast<Expr*>(val);
1683
1684  // The scope passed in may not be a decl scope.  Zip up the scope tree until
1685  // we find one that is.
1686  while ((S->getFlags() & Scope::DeclScope) == 0)
1687    S = S->getParent();
1688
1689  // Verify that there isn't already something declared with this name in this
1690  // scope.
1691  if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) {
1692    if (S->isDeclScope(PrevDecl)) {
1693      if (isa<EnumConstantDecl>(PrevDecl))
1694        Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName());
1695      else
1696        Diag(IdLoc, diag::err_redefinition, Id->getName());
1697      Diag(PrevDecl->getLocation(), diag::err_previous_definition);
1698      delete Val;
1699      return 0;
1700    }
1701  }
1702
1703  llvm::APSInt EnumVal(32);
1704  QualType EltTy;
1705  if (Val) {
1706    // Make sure to promote the operand type to int.
1707    UsualUnaryConversions(Val);
1708
1709    // C99 6.7.2.2p2: Make sure we have an integer constant expression.
1710    SourceLocation ExpLoc;
1711    if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) {
1712      Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr,
1713           Id->getName());
1714      delete Val;
1715      Val = 0;  // Just forget about it.
1716    } else {
1717      EltTy = Val->getType();
1718    }
1719  }
1720
1721  if (!Val) {
1722    if (LastEnumConst) {
1723      // Assign the last value + 1.
1724      EnumVal = LastEnumConst->getInitVal();
1725      ++EnumVal;
1726
1727      // Check for overflow on increment.
1728      if (EnumVal < LastEnumConst->getInitVal())
1729        Diag(IdLoc, diag::warn_enum_value_overflow);
1730
1731      EltTy = LastEnumConst->getType();
1732    } else {
1733      // First value, set to zero.
1734      EltTy = Context.IntTy;
1735      EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy)));
1736    }
1737  }
1738
1739  EnumConstantDecl *New =
1740    EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy,
1741                             Val, EnumVal,
1742                             LastEnumConst);
1743
1744  // Register this decl in the current scope stack.
1745  PushOnScopeChains(New, S);
1746  return New;
1747}
1748
1749void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX,
1750                         DeclTy **Elements, unsigned NumElements) {
1751  EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX));
1752  assert(!Enum->isDefinition() && "Enum redefinitions can't reach here");
1753
1754  // TODO: If the result value doesn't fit in an int, it must be a long or long
1755  // long value.  ISO C does not support this, but GCC does as an extension,
1756  // emit a warning.
1757  unsigned IntWidth = Context.Target.getIntWidth();
1758
1759  // Verify that all the values are okay, compute the size of the values, and
1760  // reverse the list.
1761  unsigned NumNegativeBits = 0;
1762  unsigned NumPositiveBits = 0;
1763
1764  // Keep track of whether all elements have type int.
1765  bool AllElementsInt = true;
1766
1767  EnumConstantDecl *EltList = 0;
1768  for (unsigned i = 0; i != NumElements; ++i) {
1769    EnumConstantDecl *ECD =
1770      cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i]));
1771    if (!ECD) continue;  // Already issued a diagnostic.
1772
1773    // If the enum value doesn't fit in an int, emit an extension warning.
1774    const llvm::APSInt &InitVal = ECD->getInitVal();
1775    assert(InitVal.getBitWidth() >= IntWidth &&
1776           "Should have promoted value to int");
1777    if (InitVal.getBitWidth() > IntWidth) {
1778      llvm::APSInt V(InitVal);
1779      V.trunc(IntWidth);
1780      V.extend(InitVal.getBitWidth());
1781      if (V != InitVal)
1782        Diag(ECD->getLocation(), diag::ext_enum_value_not_int,
1783             InitVal.toString());
1784    }
1785
1786    // Keep track of the size of positive and negative values.
1787    if (InitVal.isUnsigned() || InitVal.isNonNegative())
1788      NumPositiveBits = std::max(NumPositiveBits,
1789                                 (unsigned)InitVal.getActiveBits());
1790    else
1791      NumNegativeBits = std::max(NumNegativeBits,
1792                                 (unsigned)InitVal.getMinSignedBits());
1793
1794    // Keep track of whether every enum element has type int (very commmon).
1795    if (AllElementsInt)
1796      AllElementsInt = ECD->getType() == Context.IntTy;
1797
1798    ECD->setNextDeclarator(EltList);
1799    EltList = ECD;
1800  }
1801
1802  // Figure out the type that should be used for this enum.
1803  // FIXME: Support attribute(packed) on enums and -fshort-enums.
1804  QualType BestType;
1805  unsigned BestWidth;
1806
1807  if (NumNegativeBits) {
1808    // If there is a negative value, figure out the smallest integer type (of
1809    // int/long/longlong) that fits.
1810    if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) {
1811      BestType = Context.IntTy;
1812      BestWidth = IntWidth;
1813    } else {
1814      BestWidth = Context.Target.getLongWidth();
1815
1816      if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth)
1817        BestType = Context.LongTy;
1818      else {
1819        BestWidth = Context.Target.getLongLongWidth();
1820
1821        if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth)
1822          Diag(Enum->getLocation(), diag::warn_enum_too_large);
1823        BestType = Context.LongLongTy;
1824      }
1825    }
1826  } else {
1827    // If there is no negative value, figure out which of uint, ulong, ulonglong
1828    // fits.
1829    if (NumPositiveBits <= IntWidth) {
1830      BestType = Context.UnsignedIntTy;
1831      BestWidth = IntWidth;
1832    } else if (NumPositiveBits <=
1833               (BestWidth = Context.Target.getLongWidth())) {
1834      BestType = Context.UnsignedLongTy;
1835    } else {
1836      BestWidth = Context.Target.getLongLongWidth();
1837      assert(NumPositiveBits <= BestWidth &&
1838             "How could an initializer get larger than ULL?");
1839      BestType = Context.UnsignedLongLongTy;
1840    }
1841  }
1842
1843  // Loop over all of the enumerator constants, changing their types to match
1844  // the type of the enum if needed.
1845  for (unsigned i = 0; i != NumElements; ++i) {
1846    EnumConstantDecl *ECD =
1847      cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i]));
1848    if (!ECD) continue;  // Already issued a diagnostic.
1849
1850    // Standard C says the enumerators have int type, but we allow, as an
1851    // extension, the enumerators to be larger than int size.  If each
1852    // enumerator value fits in an int, type it as an int, otherwise type it the
1853    // same as the enumerator decl itself.  This means that in "enum { X = 1U }"
1854    // that X has type 'int', not 'unsigned'.
1855    if (ECD->getType() == Context.IntTy) {
1856      // Make sure the init value is signed.
1857      llvm::APSInt IV = ECD->getInitVal();
1858      IV.setIsSigned(true);
1859      ECD->setInitVal(IV);
1860      continue;  // Already int type.
1861    }
1862
1863    // Determine whether the value fits into an int.
1864    llvm::APSInt InitVal = ECD->getInitVal();
1865    bool FitsInInt;
1866    if (InitVal.isUnsigned() || !InitVal.isNegative())
1867      FitsInInt = InitVal.getActiveBits() < IntWidth;
1868    else
1869      FitsInInt = InitVal.getMinSignedBits() <= IntWidth;
1870
1871    // If it fits into an integer type, force it.  Otherwise force it to match
1872    // the enum decl type.
1873    QualType NewTy;
1874    unsigned NewWidth;
1875    bool NewSign;
1876    if (FitsInInt) {
1877      NewTy = Context.IntTy;
1878      NewWidth = IntWidth;
1879      NewSign = true;
1880    } else if (ECD->getType() == BestType) {
1881      // Already the right type!
1882      continue;
1883    } else {
1884      NewTy = BestType;
1885      NewWidth = BestWidth;
1886      NewSign = BestType->isSignedIntegerType();
1887    }
1888
1889    // Adjust the APSInt value.
1890    InitVal.extOrTrunc(NewWidth);
1891    InitVal.setIsSigned(NewSign);
1892    ECD->setInitVal(InitVal);
1893
1894    // Adjust the Expr initializer and type.
1895    ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr()));
1896    ECD->setType(NewTy);
1897  }
1898
1899  Enum->defineElements(EltList, BestType);
1900  Consumer.HandleTagDeclDefinition(Enum);
1901}
1902
1903Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc,
1904                                          ExprTy *expr) {
1905  StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr);
1906
1907  return FileScopeAsmDecl::Create(Context, Loc, AsmString);
1908}
1909
1910Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc,
1911                                     SourceLocation LBrace,
1912                                     SourceLocation RBrace,
1913                                     const char *Lang,
1914                                     unsigned StrSize,
1915                                     DeclTy *D) {
1916  LinkageSpecDecl::LanguageIDs Language;
1917  Decl *dcl = static_cast<Decl *>(D);
1918  if (strncmp(Lang, "\"C\"", StrSize) == 0)
1919    Language = LinkageSpecDecl::lang_c;
1920  else if (strncmp(Lang, "\"C++\"", StrSize) == 0)
1921    Language = LinkageSpecDecl::lang_cxx;
1922  else {
1923    Diag(Loc, diag::err_bad_language);
1924    return 0;
1925  }
1926
1927  // FIXME: Add all the various semantics of linkage specifications
1928  return LinkageSpecDecl::Create(Context, Loc, Language, dcl);
1929}
1930
1931void Sema::HandleDeclAttribute(Decl *New, AttributeList *Attr) {
1932
1933  switch (Attr->getKind()) {
1934  case AttributeList::AT_vector_size:
1935    if (ValueDecl *vDecl = dyn_cast<ValueDecl>(New)) {
1936      QualType newType = HandleVectorTypeAttribute(vDecl->getType(), Attr);
1937      if (!newType.isNull()) // install the new vector type into the decl
1938        vDecl->setType(newType);
1939    }
1940    if (TypedefDecl *tDecl = dyn_cast<TypedefDecl>(New)) {
1941      QualType newType = HandleVectorTypeAttribute(tDecl->getUnderlyingType(),
1942                                                   Attr);
1943      if (!newType.isNull()) // install the new vector type into the decl
1944        tDecl->setUnderlyingType(newType);
1945    }
1946    break;
1947  case AttributeList::AT_ext_vector_type:
1948    if (TypedefDecl *tDecl = dyn_cast<TypedefDecl>(New))
1949      HandleExtVectorTypeAttribute(tDecl, Attr);
1950    else
1951      Diag(Attr->getLoc(),
1952           diag::err_typecheck_ext_vector_not_typedef);
1953    break;
1954  case AttributeList::AT_address_space:
1955    if (TypedefDecl *tDecl = dyn_cast<TypedefDecl>(New)) {
1956      QualType newType = HandleAddressSpaceTypeAttribute(
1957                                                  tDecl->getUnderlyingType(),
1958                                                  Attr);
1959      tDecl->setUnderlyingType(newType);
1960    } else if (ValueDecl *vDecl = dyn_cast<ValueDecl>(New)) {
1961      QualType newType = HandleAddressSpaceTypeAttribute(vDecl->getType(),
1962                                                         Attr);
1963      // install the new addr spaced type into the decl
1964      vDecl->setType(newType);
1965    }
1966    break;
1967  case AttributeList::AT_deprecated:
1968    HandleDeprecatedAttribute(New, Attr);
1969    break;
1970  case AttributeList::AT_visibility:
1971    HandleVisibilityAttribute(New, Attr);
1972    break;
1973  case AttributeList::AT_weak:
1974    HandleWeakAttribute(New, Attr);
1975    break;
1976  case AttributeList::AT_dllimport:
1977    HandleDLLImportAttribute(New, Attr);
1978    break;
1979  case AttributeList::AT_dllexport:
1980    HandleDLLExportAttribute(New, Attr);
1981    break;
1982  case AttributeList::AT_nothrow:
1983    HandleNothrowAttribute(New, Attr);
1984    break;
1985  case AttributeList::AT_stdcall:
1986    HandleStdCallAttribute(New, Attr);
1987    break;
1988  case AttributeList::AT_fastcall:
1989    HandleFastCallAttribute(New, Attr);
1990    break;
1991  case AttributeList::AT_aligned:
1992    HandleAlignedAttribute(New, Attr);
1993    break;
1994  case AttributeList::AT_packed:
1995    HandlePackedAttribute(New, Attr);
1996    break;
1997  case AttributeList::AT_annotate:
1998    HandleAnnotateAttribute(New, Attr);
1999    break;
2000  case AttributeList::AT_noreturn:
2001    HandleNoReturnAttribute(New, Attr);
2002    break;
2003  case AttributeList::AT_format:
2004    HandleFormatAttribute(New, Attr);
2005    break;
2006  default:
2007#if 0
2008    // TODO: when we have the full set of attributes, warn about unknown ones.
2009    Diag(Attr->getLoc(), diag::warn_attribute_ignored,
2010         Attr->getName()->getName());
2011#endif
2012    break;
2013  }
2014}
2015
2016void Sema::HandleDeclAttributes(Decl *New, AttributeList *declspec_prefix,
2017                                AttributeList *declarator_postfix) {
2018  while (declspec_prefix) {
2019    HandleDeclAttribute(New, declspec_prefix);
2020    declspec_prefix = declspec_prefix->getNext();
2021  }
2022  while (declarator_postfix) {
2023    HandleDeclAttribute(New, declarator_postfix);
2024    declarator_postfix = declarator_postfix->getNext();
2025  }
2026}
2027
2028void Sema::HandleExtVectorTypeAttribute(TypedefDecl *tDecl,
2029                                        AttributeList *rawAttr) {
2030  QualType curType = tDecl->getUnderlyingType();
2031  // check the attribute arguments.
2032  if (rawAttr->getNumArgs() != 1) {
2033    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2034         std::string("1"));
2035    return;
2036  }
2037  Expr *sizeExpr = static_cast<Expr *>(rawAttr->getArg(0));
2038  llvm::APSInt vecSize(32);
2039  if (!sizeExpr->isIntegerConstantExpr(vecSize, Context)) {
2040    Diag(rawAttr->getLoc(), diag::err_attribute_argument_not_int,
2041         "ext_vector_type", sizeExpr->getSourceRange());
2042    return;
2043  }
2044  // unlike gcc's vector_size attribute, we do not allow vectors to be defined
2045  // in conjunction with complex types (pointers, arrays, functions, etc.).
2046  Type *canonType = curType.getCanonicalType().getTypePtr();
2047  if (!(canonType->isIntegerType() || canonType->isRealFloatingType())) {
2048    Diag(rawAttr->getLoc(), diag::err_attribute_invalid_vector_type,
2049         curType.getCanonicalType().getAsString());
2050    return;
2051  }
2052  // unlike gcc's vector_size attribute, the size is specified as the
2053  // number of elements, not the number of bytes.
2054  unsigned vectorSize = static_cast<unsigned>(vecSize.getZExtValue());
2055
2056  if (vectorSize == 0) {
2057    Diag(rawAttr->getLoc(), diag::err_attribute_zero_size,
2058         sizeExpr->getSourceRange());
2059    return;
2060  }
2061  // Instantiate/Install the vector type, the number of elements is > 0.
2062  tDecl->setUnderlyingType(Context.getExtVectorType(curType, vectorSize));
2063  // Remember this typedef decl, we will need it later for diagnostics.
2064  ExtVectorDecls.push_back(tDecl);
2065}
2066
2067QualType Sema::HandleVectorTypeAttribute(QualType curType,
2068                                         AttributeList *rawAttr) {
2069  // check the attribute arugments.
2070  if (rawAttr->getNumArgs() != 1) {
2071    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2072         std::string("1"));
2073    return QualType();
2074  }
2075  Expr *sizeExpr = static_cast<Expr *>(rawAttr->getArg(0));
2076  llvm::APSInt vecSize(32);
2077  if (!sizeExpr->isIntegerConstantExpr(vecSize, Context)) {
2078    Diag(rawAttr->getLoc(), diag::err_attribute_argument_not_int,
2079         "vector_size", sizeExpr->getSourceRange());
2080    return QualType();
2081  }
2082  // navigate to the base type - we need to provide for vector pointers,
2083  // vector arrays, and functions returning vectors.
2084  Type *canonType = curType.getCanonicalType().getTypePtr();
2085
2086  if (canonType->isPointerType() || canonType->isArrayType() ||
2087      canonType->isFunctionType()) {
2088    assert(0 && "HandleVector(): Complex type construction unimplemented");
2089    /* FIXME: rebuild the type from the inside out, vectorizing the inner type.
2090        do {
2091          if (PointerType *PT = dyn_cast<PointerType>(canonType))
2092            canonType = PT->getPointeeType().getTypePtr();
2093          else if (ArrayType *AT = dyn_cast<ArrayType>(canonType))
2094            canonType = AT->getElementType().getTypePtr();
2095          else if (FunctionType *FT = dyn_cast<FunctionType>(canonType))
2096            canonType = FT->getResultType().getTypePtr();
2097        } while (canonType->isPointerType() || canonType->isArrayType() ||
2098                 canonType->isFunctionType());
2099    */
2100  }
2101  // the base type must be integer or float.
2102  if (!(canonType->isIntegerType() || canonType->isRealFloatingType())) {
2103    Diag(rawAttr->getLoc(), diag::err_attribute_invalid_vector_type,
2104         curType.getCanonicalType().getAsString());
2105    return QualType();
2106  }
2107  unsigned typeSize = static_cast<unsigned>(Context.getTypeSize(curType));
2108  // vecSize is specified in bytes - convert to bits.
2109  unsigned vectorSize = static_cast<unsigned>(vecSize.getZExtValue() * 8);
2110
2111  // the vector size needs to be an integral multiple of the type size.
2112  if (vectorSize % typeSize) {
2113    Diag(rawAttr->getLoc(), diag::err_attribute_invalid_size,
2114         sizeExpr->getSourceRange());
2115    return QualType();
2116  }
2117  if (vectorSize == 0) {
2118    Diag(rawAttr->getLoc(), diag::err_attribute_zero_size,
2119         sizeExpr->getSourceRange());
2120    return QualType();
2121  }
2122  // Instantiate the vector type, the number of elements is > 0, and not
2123  // required to be a power of 2, unlike GCC.
2124  return Context.getVectorType(curType, vectorSize/typeSize);
2125}
2126
2127void Sema::HandlePackedAttribute(Decl *d, AttributeList *rawAttr) {
2128  // check the attribute arguments.
2129  if (rawAttr->getNumArgs() > 0) {
2130    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2131         std::string("0"));
2132    return;
2133  }
2134
2135  if (TagDecl *TD = dyn_cast<TagDecl>(d))
2136    TD->addAttr(new PackedAttr);
2137  else if (FieldDecl *FD = dyn_cast<FieldDecl>(d)) {
2138    // If the alignment is less than or equal to 8 bits, the packed attribute
2139    // has no effect.
2140    if (Context.getTypeAlign(FD->getType()) <= 8)
2141      Diag(rawAttr->getLoc(),
2142           diag::warn_attribute_ignored_for_field_of_type,
2143           rawAttr->getName()->getName(), FD->getType().getAsString());
2144    else
2145      FD->addAttr(new PackedAttr);
2146  } else
2147    Diag(rawAttr->getLoc(), diag::warn_attribute_ignored,
2148         rawAttr->getName()->getName());
2149}
2150
2151void Sema::HandleNoReturnAttribute(Decl *d, AttributeList *rawAttr) {
2152  // check the attribute arguments.
2153  if (rawAttr->getNumArgs() != 0) {
2154    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2155         std::string("0"));
2156    return;
2157  }
2158
2159  FunctionDecl *Fn = dyn_cast<FunctionDecl>(d);
2160
2161  if (!Fn) {
2162    Diag(rawAttr->getLoc(), diag::warn_attribute_wrong_decl_type,
2163         "noreturn", "function");
2164    return;
2165  }
2166
2167  d->addAttr(new NoReturnAttr());
2168}
2169
2170void Sema::HandleDeprecatedAttribute(Decl *d, AttributeList *rawAttr) {
2171  // check the attribute arguments.
2172  if (rawAttr->getNumArgs() != 0) {
2173    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2174         std::string("0"));
2175    return;
2176  }
2177
2178  d->addAttr(new DeprecatedAttr());
2179}
2180
2181void Sema::HandleVisibilityAttribute(Decl *d, AttributeList *rawAttr) {
2182  // check the attribute arguments.
2183  if (rawAttr->getNumArgs() != 1) {
2184    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2185         std::string("1"));
2186    return;
2187  }
2188
2189  Expr *Arg = static_cast<Expr*>(rawAttr->getArg(0));
2190  Arg = Arg->IgnoreParenCasts();
2191  StringLiteral *Str = dyn_cast<StringLiteral>(Arg);
2192
2193  if (Str == 0 || Str->isWide()) {
2194    Diag(rawAttr->getLoc(), diag::err_attribute_argument_n_not_string,
2195         "visibility", std::string("1"));
2196    return;
2197  }
2198
2199  const char *TypeStr = Str->getStrData();
2200  unsigned TypeLen = Str->getByteLength();
2201  llvm::GlobalValue::VisibilityTypes type;
2202
2203  if (TypeLen == 7 && !memcmp(TypeStr, "default", 7))
2204    type = llvm::GlobalValue::DefaultVisibility;
2205  else if (TypeLen == 6 && !memcmp(TypeStr, "hidden", 6))
2206    type = llvm::GlobalValue::HiddenVisibility;
2207  else if (TypeLen == 8 && !memcmp(TypeStr, "internal", 8))
2208    type = llvm::GlobalValue::HiddenVisibility; // FIXME
2209  else if (TypeLen == 9 && !memcmp(TypeStr, "protected", 9))
2210    type = llvm::GlobalValue::ProtectedVisibility;
2211  else {
2212    Diag(rawAttr->getLoc(), diag::warn_attribute_type_not_supported,
2213           "visibility", TypeStr);
2214    return;
2215  }
2216
2217  d->addAttr(new VisibilityAttr(type));
2218}
2219
2220void Sema::HandleWeakAttribute(Decl *d, AttributeList *rawAttr) {
2221  // check the attribute arguments.
2222  if (rawAttr->getNumArgs() != 0) {
2223    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2224         std::string("0"));
2225    return;
2226  }
2227
2228  d->addAttr(new WeakAttr());
2229}
2230
2231void Sema::HandleDLLImportAttribute(Decl *d, AttributeList *rawAttr) {
2232  // check the attribute arguments.
2233  if (rawAttr->getNumArgs() != 0) {
2234    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2235         std::string("0"));
2236    return;
2237  }
2238
2239  d->addAttr(new DLLImportAttr());
2240}
2241
2242void Sema::HandleDLLExportAttribute(Decl *d, AttributeList *rawAttr) {
2243  // check the attribute arguments.
2244  if (rawAttr->getNumArgs() != 0) {
2245    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2246         std::string("0"));
2247    return;
2248  }
2249
2250  d->addAttr(new DLLExportAttr());
2251}
2252
2253void Sema::HandleStdCallAttribute(Decl *d, AttributeList *rawAttr) {
2254  // check the attribute arguments.
2255  if (rawAttr->getNumArgs() != 0) {
2256    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2257         std::string("0"));
2258    return;
2259  }
2260
2261  d->addAttr(new StdCallAttr());
2262}
2263
2264void Sema::HandleFastCallAttribute(Decl *d, AttributeList *rawAttr) {
2265  // check the attribute arguments.
2266  if (rawAttr->getNumArgs() != 0) {
2267    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2268         std::string("0"));
2269    return;
2270  }
2271
2272  d->addAttr(new FastCallAttr());
2273}
2274
2275void Sema::HandleNothrowAttribute(Decl *d, AttributeList *rawAttr) {
2276  // check the attribute arguments.
2277  if (rawAttr->getNumArgs() != 0) {
2278    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2279         std::string("0"));
2280    return;
2281  }
2282
2283  d->addAttr(new NoThrowAttr());
2284}
2285
2286static const FunctionTypeProto *getFunctionProto(Decl *d) {
2287  QualType Ty;
2288
2289  if (ValueDecl *decl = dyn_cast<ValueDecl>(d))
2290    Ty = decl->getType();
2291  else if (FieldDecl *decl = dyn_cast<FieldDecl>(d))
2292    Ty = decl->getType();
2293  else
2294    return 0;
2295
2296  if (Ty->isFunctionPointerType()) {
2297    const PointerType *PtrTy = Ty->getAsPointerType();
2298    Ty = PtrTy->getPointeeType();
2299  }
2300
2301  if (const FunctionType *FnTy = Ty->getAsFunctionType())
2302    return dyn_cast<FunctionTypeProto>(FnTy->getAsFunctionType());
2303
2304  return 0;
2305}
2306
2307
2308/// Handle __attribute__((format(type,idx,firstarg))) attributes
2309/// based on http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
2310void Sema::HandleFormatAttribute(Decl *d, AttributeList *rawAttr) {
2311
2312  if (!rawAttr->getParameterName()) {
2313    Diag(rawAttr->getLoc(), diag::err_attribute_argument_n_not_string,
2314           "format", std::string("1"));
2315    return;
2316  }
2317
2318  if (rawAttr->getNumArgs() != 2) {
2319    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2320         std::string("3"));
2321    return;
2322  }
2323
2324  // GCC ignores the format attribute on K&R style function
2325  // prototypes, so we ignore it as well
2326  const FunctionTypeProto *proto = getFunctionProto(d);
2327
2328  if (!proto) {
2329    Diag(rawAttr->getLoc(), diag::warn_attribute_wrong_decl_type,
2330           "format", "function");
2331    return;
2332  }
2333
2334  // FIXME: in C++ the implicit 'this' function parameter also counts.
2335  // this is needed in order to be compatible with GCC
2336  // the index must start in 1 and the limit is numargs+1
2337  unsigned NumArgs  = proto->getNumArgs();
2338  unsigned FirstIdx = 1;
2339
2340  const char *Format = rawAttr->getParameterName()->getName();
2341  unsigned FormatLen = rawAttr->getParameterName()->getLength();
2342
2343  // Normalize the argument, __foo__ becomes foo.
2344  if (FormatLen > 4 && Format[0] == '_' && Format[1] == '_' &&
2345      Format[FormatLen - 2] == '_' && Format[FormatLen - 1] == '_') {
2346    Format += 2;
2347    FormatLen -= 4;
2348  }
2349
2350  if (!((FormatLen == 5 && !memcmp(Format, "scanf", 5))
2351     || (FormatLen == 6 && !memcmp(Format, "printf", 6))
2352     || (FormatLen == 7 && !memcmp(Format, "strfmon", 7))
2353     || (FormatLen == 8 && !memcmp(Format, "strftime", 8)))) {
2354    Diag(rawAttr->getLoc(), diag::warn_attribute_type_not_supported,
2355           "format", rawAttr->getParameterName()->getName());
2356    return;
2357  }
2358
2359  // checks for the 2nd argument
2360  Expr *IdxExpr = static_cast<Expr *>(rawAttr->getArg(0));
2361  llvm::APSInt Idx(Context.getTypeSize(IdxExpr->getType()));
2362  if (!IdxExpr->isIntegerConstantExpr(Idx, Context)) {
2363    Diag(rawAttr->getLoc(), diag::err_attribute_argument_n_not_int,
2364           "format", std::string("2"), IdxExpr->getSourceRange());
2365    return;
2366  }
2367
2368  if (Idx.getZExtValue() < FirstIdx || Idx.getZExtValue() > NumArgs) {
2369    Diag(rawAttr->getLoc(), diag::err_attribute_argument_out_of_bounds,
2370           "format", std::string("2"), IdxExpr->getSourceRange());
2371    return;
2372  }
2373
2374  // make sure the format string is really a string
2375  QualType Ty = proto->getArgType(Idx.getZExtValue()-1);
2376  if (!Ty->isPointerType() ||
2377      !Ty->getAsPointerType()->getPointeeType()->isCharType()) {
2378    Diag(rawAttr->getLoc(), diag::err_format_attribute_not_string,
2379         IdxExpr->getSourceRange());
2380    return;
2381  }
2382
2383
2384  // check the 3rd argument
2385  Expr *FirstArgExpr = static_cast<Expr *>(rawAttr->getArg(1));
2386  llvm::APSInt FirstArg(Context.getTypeSize(FirstArgExpr->getType()));
2387  if (!FirstArgExpr->isIntegerConstantExpr(FirstArg, Context)) {
2388    Diag(rawAttr->getLoc(), diag::err_attribute_argument_n_not_int,
2389           "format", std::string("3"), FirstArgExpr->getSourceRange());
2390    return;
2391  }
2392
2393  // check if the function is variadic if the 3rd argument non-zero
2394  if (FirstArg != 0) {
2395    if (proto->isVariadic()) {
2396      ++NumArgs; // +1 for ...
2397    } else {
2398      Diag(d->getLocation(), diag::err_format_attribute_requires_variadic);
2399      return;
2400    }
2401  }
2402
2403  // strftime requires FirstArg to be 0 because it doesn't read from any variable
2404  // the input is just the current time + the format string
2405  if (FormatLen == 8 && !memcmp(Format, "strftime", 8)) {
2406    if (FirstArg != 0) {
2407      Diag(rawAttr->getLoc(), diag::err_format_strftime_third_parameter,
2408             FirstArgExpr->getSourceRange());
2409      return;
2410    }
2411  // if 0 it disables parameter checking (to use with e.g. va_list)
2412  } else if (FirstArg != 0 && FirstArg != NumArgs) {
2413    Diag(rawAttr->getLoc(), diag::err_attribute_argument_out_of_bounds,
2414           "format", std::string("3"), FirstArgExpr->getSourceRange());
2415    return;
2416  }
2417
2418  d->addAttr(new FormatAttr(std::string(Format, FormatLen),
2419                            Idx.getZExtValue(), FirstArg.getZExtValue()));
2420}
2421
2422void Sema::HandleAnnotateAttribute(Decl *d, AttributeList *rawAttr) {
2423  // check the attribute arguments.
2424  if (rawAttr->getNumArgs() != 1) {
2425    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2426         std::string("1"));
2427    return;
2428  }
2429  Expr *argExpr = static_cast<Expr *>(rawAttr->getArg(0));
2430  StringLiteral *SE = dyn_cast<StringLiteral>(argExpr);
2431
2432  // Make sure that there is a string literal as the annotation's single
2433  // argument.
2434  if (!SE) {
2435    Diag(rawAttr->getLoc(), diag::err_attribute_annotate_no_string);
2436    return;
2437  }
2438  d->addAttr(new AnnotateAttr(std::string(SE->getStrData(),
2439                                          SE->getByteLength())));
2440}
2441
2442void Sema::HandleAlignedAttribute(Decl *d, AttributeList *rawAttr)
2443{
2444  // check the attribute arguments.
2445  if (rawAttr->getNumArgs() > 1) {
2446    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
2447         std::string("1"));
2448    return;
2449  }
2450
2451  unsigned Align = 0;
2452
2453  if (rawAttr->getNumArgs() == 0) {
2454    // FIXME: This should be the target specific maximum alignment.
2455    // (For now we just use 128 bits which is the maximum on X86.
2456    Align = 128;
2457    return;
2458  } else {
2459    Expr *alignmentExpr = static_cast<Expr *>(rawAttr->getArg(0));
2460    llvm::APSInt alignment(32);
2461    if (!alignmentExpr->isIntegerConstantExpr(alignment, Context)) {
2462      Diag(rawAttr->getLoc(), diag::err_attribute_argument_not_int,
2463           "aligned", alignmentExpr->getSourceRange());
2464      return;
2465    }
2466
2467    Align = alignment.getZExtValue() * 8;
2468  }
2469
2470  d->addAttr(new AlignedAttr(Align));
2471}
2472