SemaDecl.cpp revision a4755c6ffab02586162170199d0c0594efaa273c
1//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file implements semantic analysis for declarations.
11//
12//===----------------------------------------------------------------------===//
13
14#include "Sema.h"
15#include "clang/AST/APValue.h"
16#include "clang/AST/ASTConsumer.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/Attr.h"
19#include "clang/AST/Builtins.h"
20#include "clang/AST/Decl.h"
21#include "clang/AST/DeclCXX.h"
22#include "clang/AST/Expr.h"
23#include "clang/AST/ExprCXX.h"
24#include "clang/AST/Type.h"
25#include "clang/Parse/DeclSpec.h"
26#include "clang/Parse/Scope.h"
27#include "clang/Basic/LangOptions.h"
28#include "clang/Basic/TargetInfo.h"
29#include "clang/Basic/SourceManager.h"
30// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's)
31#include "clang/Lex/Preprocessor.h"
32#include "clang/Lex/HeaderSearch.h"
33#include "llvm/ADT/SmallString.h"
34#include "llvm/ADT/SmallSet.h"
35#include "llvm/ADT/DenseSet.h"
36using namespace clang;
37
38Sema::TypeTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S) {
39  Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, false);
40
41  if (IIDecl && (isa<TypedefDecl>(IIDecl) ||
42                 isa<ObjCInterfaceDecl>(IIDecl) ||
43                 isa<TagDecl>(IIDecl)))
44    return IIDecl;
45  return 0;
46}
47
48DeclContext *Sema::getDCParent(DeclContext *DC) {
49  // If CurContext is a ObjC method, getParent() will return NULL.
50  if (isa<ObjCMethodDecl>(DC))
51    return Context.getTranslationUnitDecl();
52
53  // A C++ inline method is parsed *after* the topmost class it was declared in
54  // is fully parsed (it's "complete").
55  // The parsing of a C++ inline method happens at the declaration context of
56  // the topmost (non-nested) class it is declared in.
57  if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) {
58    assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record.");
59    DC = MD->getParent();
60    while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getParent()))
61      DC = RD;
62
63    // Return the declaration context of the topmost class the inline method is
64    // declared in.
65    return DC;
66  }
67
68  return DC->getParent();
69}
70
71void Sema::PushDeclContext(DeclContext *DC) {
72  assert(getDCParent(DC) == CurContext &&
73       "The next DeclContext should be directly contained in the current one.");
74  CurContext = DC;
75}
76
77void Sema::PopDeclContext() {
78  assert(CurContext && "DeclContext imbalance!");
79  CurContext = getDCParent(CurContext);
80}
81
82/// Add this decl to the scope shadowed decl chains.
83void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) {
84  S->AddDecl(D);
85
86  // C++ [basic.scope]p4:
87  //   -- exactly one declaration shall declare a class name or
88  //   enumeration name that is not a typedef name and the other
89  //   declarations shall all refer to the same object or
90  //   enumerator, or all refer to functions and function templates;
91  //   in this case the class name or enumeration name is hidden.
92  if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
93    // We are pushing the name of a tag (enum or class).
94    IdentifierResolver::iterator
95        I = IdResolver.begin(TD->getIdentifier(),
96                             TD->getDeclContext(), false/*LookInParentCtx*/);
97    if (I != IdResolver.end() &&
98        IdResolver.isDeclInScope(*I, TD->getDeclContext(), S)) {
99      // There is already a declaration with the same name in the same
100      // scope. It must be found before we find the new declaration,
101      // so swap the order on the shadowed declaration chain.
102
103      IdResolver.AddShadowedDecl(TD, *I);
104      return;
105    }
106  }
107  IdResolver.AddDecl(D);
108}
109
110void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) {
111  if (S->decl_empty()) return;
112  assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!");
113
114  for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end();
115       I != E; ++I) {
116    Decl *TmpD = static_cast<Decl*>(*I);
117    assert(TmpD && "This decl didn't get pushed??");
118
119    if (isa<CXXFieldDecl>(TmpD)) continue;
120
121    assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?");
122    ScopedDecl *D = cast<ScopedDecl>(TmpD);
123
124    IdentifierInfo *II = D->getIdentifier();
125    if (!II) continue;
126
127    // We only want to remove the decls from the identifier decl chains for local
128    // scopes, when inside a function/method.
129    if (S->getFnParent() != 0)
130      IdResolver.RemoveDecl(D);
131
132    // Chain this decl to the containing DeclContext.
133    D->setNext(CurContext->getDeclChain());
134    CurContext->setDeclChain(D);
135  }
136}
137
138/// getObjCInterfaceDecl - Look up a for a class declaration in the scope.
139/// return 0 if one not found.
140ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) {
141  // The third "scope" argument is 0 since we aren't enabling lazy built-in
142  // creation from this context.
143  Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false);
144
145  return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl);
146}
147
148/// LookupDecl - Look up the inner-most declaration in the specified
149/// namespace.
150Decl *Sema::LookupDecl(const IdentifierInfo *II, unsigned NSI,
151                       Scope *S, bool enableLazyBuiltinCreation) {
152  if (II == 0) return 0;
153  unsigned NS = NSI;
154  if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary))
155    NS |= Decl::IDNS_Tag;
156
157  // Scan up the scope chain looking for a decl that matches this identifier
158  // that is in the appropriate namespace.  This search should not take long, as
159  // shadowing of names is uncommon, and deep shadowing is extremely uncommon.
160  for (IdentifierResolver::iterator
161       I = IdResolver.begin(II, CurContext), E = IdResolver.end(); I != E; ++I)
162    if ((*I)->getIdentifierNamespace() & NS)
163      return *I;
164
165  // If we didn't find a use of this identifier, and if the identifier
166  // corresponds to a compiler builtin, create the decl object for the builtin
167  // now, injecting it into translation unit scope, and return it.
168  if (NS & Decl::IDNS_Ordinary) {
169    if (enableLazyBuiltinCreation) {
170      // If this is a builtin on this (or all) targets, create the decl.
171      if (unsigned BuiltinID = II->getBuiltinID())
172        return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S);
173    }
174    if (getLangOptions().ObjC1) {
175      // @interface and @compatibility_alias introduce typedef-like names.
176      // Unlike typedef's, they can only be introduced at file-scope (and are
177      // therefore not scoped decls). They can, however, be shadowed by
178      // other names in IDNS_Ordinary.
179      ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II);
180      if (IDI != ObjCInterfaceDecls.end())
181        return IDI->second;
182      ObjCAliasTy::iterator I = ObjCAliasDecls.find(II);
183      if (I != ObjCAliasDecls.end())
184        return I->second->getClassInterface();
185    }
186  }
187  return 0;
188}
189
190void Sema::InitBuiltinVaListType() {
191  if (!Context.getBuiltinVaListType().isNull())
192    return;
193
194  IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list");
195  Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope);
196  TypedefDecl *VaTypedef = cast<TypedefDecl>(VaDecl);
197  Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef));
198}
199
200/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope.
201/// lazily create a decl for it.
202ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid,
203                                      Scope *S) {
204  Builtin::ID BID = (Builtin::ID)bid;
205
206  if (BID == Builtin::BI__builtin_va_start ||
207      BID == Builtin::BI__builtin_va_copy ||
208      BID == Builtin::BI__builtin_va_end ||
209      BID == Builtin::BI__builtin_stdarg_start)
210    InitBuiltinVaListType();
211
212  QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context);
213  FunctionDecl *New = FunctionDecl::Create(Context,
214                                           Context.getTranslationUnitDecl(),
215                                           SourceLocation(), II, R,
216                                           FunctionDecl::Extern, false, 0);
217
218  // Create Decl objects for each parameter, adding them to the
219  // FunctionDecl.
220  if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(R)) {
221    llvm::SmallVector<ParmVarDecl*, 16> Params;
222    for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i)
223      Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0,
224                                           FT->getArgType(i), VarDecl::None, 0,
225                                           0));
226    New->setParams(&Params[0], Params.size());
227  }
228
229
230
231  // TUScope is the translation-unit scope to insert this function into.
232  PushOnScopeChains(New, TUScope);
233  return New;
234}
235
236/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name
237/// and scope as a previous declaration 'Old'.  Figure out how to resolve this
238/// situation, merging decls or emitting diagnostics as appropriate.
239///
240TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) {
241  // Verify the old decl was also a typedef.
242  TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD);
243  if (!Old) {
244    Diag(New->getLocation(), diag::err_redefinition_different_kind,
245         New->getName());
246    Diag(OldD->getLocation(), diag::err_previous_definition);
247    return New;
248  }
249
250  // If the typedef types are not identical, reject them in all languages and
251  // with any extensions enabled.
252  if (Old->getUnderlyingType() != New->getUnderlyingType() &&
253      Context.getCanonicalType(Old->getUnderlyingType()) !=
254      Context.getCanonicalType(New->getUnderlyingType())) {
255    Diag(New->getLocation(), diag::err_redefinition_different_typedef,
256         New->getUnderlyingType().getAsString(),
257         Old->getUnderlyingType().getAsString());
258    Diag(Old->getLocation(), diag::err_previous_definition);
259    return Old;
260  }
261
262  // Allow multiple definitions for ObjC built-in typedefs.
263  // FIXME: Verify the underlying types are equivalent!
264  if (getLangOptions().ObjC1 && isBuiltinObjCType(New))
265    return Old;
266
267  if (getLangOptions().Microsoft) return New;
268
269  // Redeclaration of a type is a constraint violation (6.7.2.3p1).
270  // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if
271  // *either* declaration is in a system header. The code below implements
272  // this adhoc compatibility rule. FIXME: The following code will not
273  // work properly when compiling ".i" files (containing preprocessed output).
274  SourceManager &SrcMgr = Context.getSourceManager();
275  HeaderSearch &HdrInfo = PP.getHeaderSearchInfo();
276  const FileEntry *OldDeclFile = SrcMgr.getFileEntryForLoc(Old->getLocation());
277  if (OldDeclFile) {
278    DirectoryLookup::DirType OldDirType = HdrInfo.getFileDirFlavor(OldDeclFile);
279    // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir.
280    if (OldDirType != DirectoryLookup::NormalHeaderDir)
281      return New;
282  }
283  const FileEntry *NewDeclFile = SrcMgr.getFileEntryForLoc(New->getLocation());
284  if (NewDeclFile) {
285    DirectoryLookup::DirType NewDirType = HdrInfo.getFileDirFlavor(NewDeclFile);
286    // Allow reclarations in both SystemHeaderDir and ExternCSystemHeaderDir.
287    if (NewDirType != DirectoryLookup::NormalHeaderDir)
288      return New;
289  }
290
291  Diag(New->getLocation(), diag::err_redefinition, New->getName());
292  Diag(Old->getLocation(), diag::err_previous_definition);
293  return New;
294}
295
296/// DeclhasAttr - returns true if decl Declaration already has the target
297/// attribute.
298static bool DeclHasAttr(const Decl *decl, const Attr *target) {
299  for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext())
300    if (attr->getKind() == target->getKind())
301      return true;
302
303  return false;
304}
305
306/// MergeAttributes - append attributes from the Old decl to the New one.
307static void MergeAttributes(Decl *New, Decl *Old) {
308  Attr *attr = const_cast<Attr*>(Old->getAttrs()), *tmp;
309
310  while (attr) {
311     tmp = attr;
312     attr = attr->getNext();
313
314    if (!DeclHasAttr(New, tmp)) {
315       New->addAttr(tmp);
316    } else {
317       tmp->setNext(0);
318       delete(tmp);
319    }
320  }
321
322  Old->invalidateAttrs();
323}
324
325/// MergeFunctionDecl - We just parsed a function 'New' from
326/// declarator D which has the same name and scope as a previous
327/// declaration 'Old'.  Figure out how to resolve this situation,
328/// merging decls or emitting diagnostics as appropriate.
329/// Redeclaration will be set true if thisNew is a redeclaration OldD.
330FunctionDecl *
331Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) {
332  Redeclaration = false;
333  // Verify the old decl was also a function.
334  FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD);
335  if (!Old) {
336    Diag(New->getLocation(), diag::err_redefinition_different_kind,
337         New->getName());
338    Diag(OldD->getLocation(), diag::err_previous_definition);
339    return New;
340  }
341
342  QualType OldQType = Context.getCanonicalType(Old->getType());
343  QualType NewQType = Context.getCanonicalType(New->getType());
344
345  // C++ [dcl.fct]p3:
346  //   All declarations for a function shall agree exactly in both the
347  //   return type and the parameter-type-list.
348  if (getLangOptions().CPlusPlus && OldQType == NewQType) {
349    MergeAttributes(New, Old);
350    Redeclaration = true;
351    return MergeCXXFunctionDecl(New, Old);
352  }
353
354  // C: Function types need to be compatible, not identical. This handles
355  // duplicate function decls like "void f(int); void f(enum X);" properly.
356  if (!getLangOptions().CPlusPlus &&
357      Context.functionTypesAreCompatible(OldQType, NewQType)) {
358    MergeAttributes(New, Old);
359    Redeclaration = true;
360    return New;
361  }
362
363  // A function that has already been declared has been redeclared or defined
364  // with a different type- show appropriate diagnostic
365  diag::kind PrevDiag;
366  if (Old->isThisDeclarationADefinition())
367    PrevDiag = diag::err_previous_definition;
368  else if (Old->isImplicit())
369    PrevDiag = diag::err_previous_implicit_declaration;
370  else
371    PrevDiag = diag::err_previous_declaration;
372
373  // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
374  // TODO: This is totally simplistic.  It should handle merging functions
375  // together etc, merging extern int X; int X; ...
376  Diag(New->getLocation(), diag::err_conflicting_types, New->getName());
377  Diag(Old->getLocation(), PrevDiag);
378  return New;
379}
380
381/// equivalentArrayTypes - Used to determine whether two array types are
382/// equivalent.
383/// We need to check this explicitly as an incomplete array definition is
384/// considered a VariableArrayType, so will not match a complete array
385/// definition that would be otherwise equivalent.
386static bool areEquivalentArrayTypes(QualType NewQType, QualType OldQType,
387                                    ASTContext &Context) {
388  const ArrayType *NewAT = Context.getAsArrayType(NewQType);
389  const ArrayType *OldAT = Context.getAsArrayType(OldQType);
390
391  if (!NewAT || !OldAT)
392    return false;
393
394  // If either (or both) array types in incomplete we need to strip off the
395  // outer VariableArrayType.  Once the outer VAT is removed the remaining
396  // types must be identical if the array types are to be considered
397  // equivalent.
398  // eg. int[][1] and int[1][1] become
399  //     VAT(null, CAT(1, int)) and CAT(1, CAT(1, int))
400  // removing the outermost VAT gives
401  //     CAT(1, int) and CAT(1, int)
402  // which are equal, therefore the array types are equivalent.
403  if (NewAT->isIncompleteArrayType() || OldAT->isIncompleteArrayType()) {
404    if (NewAT->getIndexTypeQualifier() != OldAT->getIndexTypeQualifier())
405      return false;
406    NewQType = Context.getCanonicalType(NewAT->getElementType());
407    OldQType = Context.getCanonicalType(OldAT->getElementType());
408  }
409
410  return NewQType == OldQType;
411}
412
413/// Predicate for C "tentative" external object definitions (C99 6.9.2).
414bool Sema::isTentativeDefinition(VarDecl *VD) {
415  if (VD->isFileVarDecl())
416    return (!VD->getInit() &&
417            (VD->getStorageClass() == VarDecl::None ||
418             VD->getStorageClass() == VarDecl::Static));
419  return false;
420}
421
422/// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors
423/// when dealing with C "tentative" external object definitions (C99 6.9.2).
424void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) {
425  bool VDIsTentative = isTentativeDefinition(VD);
426
427  for (IdentifierResolver::iterator
428       I = IdResolver.begin(VD->getIdentifier(),
429                            VD->getDeclContext(), false/*LookInParentCtx*/),
430       E = IdResolver.end(); I != E; ++I) {
431    if (*I != VD && IdResolver.isDeclInScope(*I, VD->getDeclContext(), S)) {
432      VarDecl *OldDecl = dyn_cast<VarDecl>(*I);
433
434      // Check for "tentative" definitions. We can't accomplish this in
435      // MergeVarDecl since the initializer hasn't been attached.
436      if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative)
437        continue;
438
439      // Handle __private_extern__ just like extern.
440      if (OldDecl->getStorageClass() != VarDecl::Extern &&
441          OldDecl->getStorageClass() != VarDecl::PrivateExtern &&
442          VD->getStorageClass() != VarDecl::Extern &&
443          VD->getStorageClass() != VarDecl::PrivateExtern) {
444        Diag(VD->getLocation(), diag::err_redefinition, VD->getName());
445        Diag(OldDecl->getLocation(), diag::err_previous_definition);
446      }
447    }
448  }
449}
450
451/// MergeVarDecl - We just parsed a variable 'New' which has the same name
452/// and scope as a previous declaration 'Old'.  Figure out how to resolve this
453/// situation, merging decls or emitting diagnostics as appropriate.
454///
455/// Tentative definition rules (C99 6.9.2p2) are checked by
456/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative
457/// definitions here, since the initializer hasn't been attached.
458///
459VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) {
460  // Verify the old decl was also a variable.
461  VarDecl *Old = dyn_cast<VarDecl>(OldD);
462  if (!Old) {
463    Diag(New->getLocation(), diag::err_redefinition_different_kind,
464         New->getName());
465    Diag(OldD->getLocation(), diag::err_previous_definition);
466    return New;
467  }
468
469  MergeAttributes(New, Old);
470
471  // Verify the types match.
472  QualType OldCType = Context.getCanonicalType(Old->getType());
473  QualType NewCType = Context.getCanonicalType(New->getType());
474  if (OldCType != NewCType &&
475      !areEquivalentArrayTypes(NewCType, OldCType, Context)) {
476    Diag(New->getLocation(), diag::err_redefinition, New->getName());
477    Diag(Old->getLocation(), diag::err_previous_definition);
478    return New;
479  }
480  // C99 6.2.2p4: Check if we have a static decl followed by a non-static.
481  if (New->getStorageClass() == VarDecl::Static &&
482      (Old->getStorageClass() == VarDecl::None ||
483       Old->getStorageClass() == VarDecl::Extern)) {
484    Diag(New->getLocation(), diag::err_static_non_static, New->getName());
485    Diag(Old->getLocation(), diag::err_previous_definition);
486    return New;
487  }
488  // C99 6.2.2p4: Check if we have a non-static decl followed by a static.
489  if (New->getStorageClass() != VarDecl::Static &&
490      Old->getStorageClass() == VarDecl::Static) {
491    Diag(New->getLocation(), diag::err_non_static_static, New->getName());
492    Diag(Old->getLocation(), diag::err_previous_definition);
493    return New;
494  }
495  // File scoped variables are analyzed in FinalizeDeclaratorGroup.
496  if (!New->isFileVarDecl()) {
497    Diag(New->getLocation(), diag::err_redefinition, New->getName());
498    Diag(Old->getLocation(), diag::err_previous_definition);
499  }
500  return New;
501}
502
503/// CheckParmsForFunctionDef - Check that the parameters of the given
504/// function are appropriate for the definition of a function. This
505/// takes care of any checks that cannot be performed on the
506/// declaration itself, e.g., that the types of each of the function
507/// parameters are complete.
508bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) {
509  bool HasInvalidParm = false;
510  for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) {
511    ParmVarDecl *Param = FD->getParamDecl(p);
512
513    // C99 6.7.5.3p4: the parameters in a parameter type list in a
514    // function declarator that is part of a function definition of
515    // that function shall not have incomplete type.
516    if (Param->getType()->isIncompleteType() &&
517        !Param->isInvalidDecl()) {
518      Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type,
519           Param->getType().getAsString());
520      Param->setInvalidDecl();
521      HasInvalidParm = true;
522    }
523  }
524
525  return HasInvalidParm;
526}
527
528/// CreateImplicitParameter - Creates an implicit function parameter
529/// in the scope S and with the given type. This routine is used, for
530/// example, to create the implicit "self" parameter in an Objective-C
531/// method.
532ImplicitParamDecl *
533Sema::CreateImplicitParameter(Scope *S, IdentifierInfo *Id,
534                              SourceLocation IdLoc, QualType Type) {
535  ImplicitParamDecl *New = ImplicitParamDecl::Create(Context, CurContext,
536      IdLoc, Id, Type, 0);
537  if (Id)
538    PushOnScopeChains(New, S);
539
540  return New;
541}
542
543/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
544/// no declarator (e.g. "struct foo;") is parsed.
545Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) {
546  // TODO: emit error on 'int;' or 'const enum foo;'.
547  // TODO: emit error on 'typedef int;'
548  // if (!DS.isMissingDeclaratorOk()) Diag(...);
549
550  return dyn_cast_or_null<TagDecl>(static_cast<Decl *>(DS.getTypeRep()));
551}
552
553bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) {
554  // Get the type before calling CheckSingleAssignmentConstraints(), since
555  // it can promote the expression.
556  QualType InitType = Init->getType();
557
558  AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init);
559  return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType,
560                                  InitType, Init, "initializing");
561}
562
563bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) {
564  const ArrayType *AT = Context.getAsArrayType(DeclT);
565
566  if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) {
567    // C99 6.7.8p14. We have an array of character type with unknown size
568    // being initialized to a string literal.
569    llvm::APSInt ConstVal(32);
570    ConstVal = strLiteral->getByteLength() + 1;
571    // Return a new array type (C99 6.7.8p22).
572    DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal,
573                                         ArrayType::Normal, 0);
574  } else {
575    const ConstantArrayType *CAT = cast<ConstantArrayType>(AT);
576    // C99 6.7.8p14. We have an array of character type with known size.
577    // FIXME: Avoid truncation for 64-bit length strings.
578    if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue())
579      Diag(strLiteral->getSourceRange().getBegin(),
580           diag::warn_initializer_string_for_char_array_too_long,
581           strLiteral->getSourceRange());
582  }
583  // Set type from "char *" to "constant array of char".
584  strLiteral->setType(DeclT);
585  // For now, we always return false (meaning success).
586  return false;
587}
588
589StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) {
590  const ArrayType *AT = Context.getAsArrayType(DeclType);
591  if (AT && AT->getElementType()->isCharType()) {
592    return dyn_cast<StringLiteral>(Init);
593  }
594  return 0;
595}
596
597bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType) {
598  // C99 6.7.8p3: The type of the entity to be initialized shall be an array
599  // of unknown size ("[]") or an object type that is not a variable array type.
600  if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType))
601    return Diag(VAT->getSizeExpr()->getLocStart(),
602                diag::err_variable_object_no_init,
603                VAT->getSizeExpr()->getSourceRange());
604
605  InitListExpr *InitList = dyn_cast<InitListExpr>(Init);
606  if (!InitList) {
607    // FIXME: Handle wide strings
608    if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType))
609      return CheckStringLiteralInit(strLiteral, DeclType);
610
611    if (DeclType->isArrayType())
612      return Diag(Init->getLocStart(),
613                  diag::err_array_init_list_required,
614                  Init->getSourceRange());
615
616    return CheckSingleInitializer(Init, DeclType);
617  }
618
619  InitListChecker CheckInitList(this, InitList, DeclType);
620  return CheckInitList.HadError();
621}
622
623Sema::DeclTy *
624Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) {
625  ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl);
626  IdentifierInfo *II = D.getIdentifier();
627
628  // All of these full declarators require an identifier.  If it doesn't have
629  // one, the ParsedFreeStandingDeclSpec action should be used.
630  if (II == 0) {
631    Diag(D.getDeclSpec().getSourceRange().getBegin(),
632         diag::err_declarator_need_ident,
633         D.getDeclSpec().getSourceRange(), D.getSourceRange());
634    return 0;
635  }
636
637  // The scope passed in may not be a decl scope.  Zip up the scope tree until
638  // we find one that is.
639  while ((S->getFlags() & Scope::DeclScope) == 0)
640    S = S->getParent();
641
642  // See if this is a redefinition of a variable in the same scope.
643  Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S);
644  ScopedDecl *New;
645  bool InvalidDecl = false;
646
647  // In C++, the previous declaration we find might be a tag type
648  // (class or enum). In this case, the new declaration will hide the
649  // tag type.
650  if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag)
651    PrevDecl = 0;
652
653  QualType R = GetTypeForDeclarator(D, S);
654  assert(!R.isNull() && "GetTypeForDeclarator() returned null type");
655
656  if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
657    // Check that there are no default arguments (C++ only).
658    if (getLangOptions().CPlusPlus)
659      CheckExtraCXXDefaultArguments(D);
660
661    TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator);
662    if (!NewTD) return 0;
663
664    // Handle attributes prior to checking for duplicates in MergeVarDecl
665    ProcessDeclAttributes(NewTD, D);
666    // Merge the decl with the existing one if appropriate. If the decl is
667    // in an outer scope, it isn't the same thing.
668    if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) {
669      NewTD = MergeTypeDefDecl(NewTD, PrevDecl);
670      if (NewTD == 0) return 0;
671    }
672    New = NewTD;
673    if (S->getFnParent() == 0) {
674      // C99 6.7.7p2: If a typedef name specifies a variably modified type
675      // then it shall have block scope.
676      if (NewTD->getUnderlyingType()->isVariablyModifiedType()) {
677        // FIXME: Diagnostic needs to be fixed.
678        Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla);
679        InvalidDecl = true;
680      }
681    }
682  } else if (R.getTypePtr()->isFunctionType()) {
683    FunctionDecl::StorageClass SC = FunctionDecl::None;
684    switch (D.getDeclSpec().getStorageClassSpec()) {
685      default: assert(0 && "Unknown storage class!");
686      case DeclSpec::SCS_auto:
687      case DeclSpec::SCS_register:
688        Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func,
689             R.getAsString());
690        InvalidDecl = true;
691        break;
692      case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break;
693      case DeclSpec::SCS_extern:      SC = FunctionDecl::Extern; break;
694      case DeclSpec::SCS_static:      SC = FunctionDecl::Static; break;
695      case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break;
696    }
697
698    bool isInline = D.getDeclSpec().isInlineSpecified();
699    FunctionDecl *NewFD;
700    if (D.getContext() == Declarator::MemberContext) {
701      // This is a C++ method declaration.
702      NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(CurContext),
703                                    D.getIdentifierLoc(), II, R,
704                                    (SC == FunctionDecl::Static), isInline,
705                                    LastDeclarator);
706    } else {
707      NewFD = FunctionDecl::Create(Context, CurContext,
708                                   D.getIdentifierLoc(),
709                                   II, R, SC, isInline,
710                                   LastDeclarator);
711    }
712    // Handle attributes.
713    ProcessDeclAttributes(NewFD, D);
714
715    // Handle GNU asm-label extension (encoded as an attribute).
716    if (Expr *E = (Expr*) D.getAsmLabel()) {
717      // The parser guarantees this is a string.
718      StringLiteral *SE = cast<StringLiteral>(E);
719      NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(),
720                                                  SE->getByteLength())));
721    }
722
723    // Copy the parameter declarations from the declarator D to
724    // the function declaration NewFD, if they are available.
725    if (D.getNumTypeObjects() > 0 &&
726        D.getTypeObject(0).Fun.hasPrototype) {
727      DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
728
729      // Create Decl objects for each parameter, adding them to the
730      // FunctionDecl.
731      llvm::SmallVector<ParmVarDecl*, 16> Params;
732
733      // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs
734      // function that takes no arguments, not a function that takes a
735      // single void argument.
736      // We let through "const void" here because Sema::GetTypeForDeclarator
737      // already checks for that case.
738      if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 &&
739          FTI.ArgInfo[0].Param &&
740          ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) {
741        // empty arg list, don't push any params.
742        ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param;
743
744        // In C++, the empty parameter-type-list must be spelled "void"; a
745        // typedef of void is not permitted.
746        if (getLangOptions().CPlusPlus &&
747            Param->getType().getUnqualifiedType() != Context.VoidTy) {
748          Diag(Param->getLocation(), diag::ext_param_typedef_of_void);
749        }
750
751      } else {
752        for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i)
753          Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param);
754      }
755
756      NewFD->setParams(&Params[0], Params.size());
757    }
758
759    // Merge the decl with the existing one if appropriate. Since C functions
760    // are in a flat namespace, make sure we consider decls in outer scopes.
761    if (PrevDecl &&
762        (!getLangOptions().CPlusPlus ||
763         IdResolver.isDeclInScope(PrevDecl, CurContext, S)) ) {
764      bool Redeclaration = false;
765      NewFD = MergeFunctionDecl(NewFD, PrevDecl, Redeclaration);
766      if (NewFD == 0) return 0;
767      if (Redeclaration) {
768        NewFD->setPreviousDeclaration(cast<FunctionDecl>(PrevDecl));
769      }
770    }
771    New = NewFD;
772
773    // In C++, check default arguments now that we have merged decls.
774    if (getLangOptions().CPlusPlus)
775      CheckCXXDefaultArguments(NewFD);
776  } else {
777    // Check that there are no default arguments (C++ only).
778    if (getLangOptions().CPlusPlus)
779      CheckExtraCXXDefaultArguments(D);
780
781    if (R.getTypePtr()->isObjCInterfaceType()) {
782      Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object,
783           D.getIdentifier()->getName());
784      InvalidDecl = true;
785    }
786
787    VarDecl *NewVD;
788    VarDecl::StorageClass SC;
789    switch (D.getDeclSpec().getStorageClassSpec()) {
790    default: assert(0 && "Unknown storage class!");
791    case DeclSpec::SCS_unspecified:    SC = VarDecl::None; break;
792    case DeclSpec::SCS_extern:         SC = VarDecl::Extern; break;
793    case DeclSpec::SCS_static:         SC = VarDecl::Static; break;
794    case DeclSpec::SCS_auto:           SC = VarDecl::Auto; break;
795    case DeclSpec::SCS_register:       SC = VarDecl::Register; break;
796    case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break;
797    }
798    if (D.getContext() == Declarator::MemberContext) {
799      assert(SC == VarDecl::Static && "Invalid storage class for member!");
800      // This is a static data member for a C++ class.
801      NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(CurContext),
802                                      D.getIdentifierLoc(), II,
803                                      R, LastDeclarator);
804    } else {
805      if (S->getFnParent() == 0) {
806        // C99 6.9p2: The storage-class specifiers auto and register shall not
807        // appear in the declaration specifiers in an external declaration.
808        if (SC == VarDecl::Auto || SC == VarDecl::Register) {
809          Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope,
810               R.getAsString());
811          InvalidDecl = true;
812        }
813        NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(),
814                                II, R, SC, LastDeclarator);
815      } else {
816        NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(),
817                                II, R, SC, LastDeclarator);
818      }
819    }
820    // Handle attributes prior to checking for duplicates in MergeVarDecl
821    ProcessDeclAttributes(NewVD, D);
822
823    // Handle GNU asm-label extension (encoded as an attribute).
824    if (Expr *E = (Expr*) D.getAsmLabel()) {
825      // The parser guarantees this is a string.
826      StringLiteral *SE = cast<StringLiteral>(E);
827      NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(),
828                                                  SE->getByteLength())));
829    }
830
831    // Emit an error if an address space was applied to decl with local storage.
832    // This includes arrays of objects with address space qualifiers, but not
833    // automatic variables that point to other address spaces.
834    // ISO/IEC TR 18037 S5.1.2
835    if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) {
836      Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl);
837      InvalidDecl = true;
838    }
839    // Merge the decl with the existing one if appropriate. If the decl is
840    // in an outer scope, it isn't the same thing.
841    if (PrevDecl && IdResolver.isDeclInScope(PrevDecl, CurContext, S)) {
842      NewVD = MergeVarDecl(NewVD, PrevDecl);
843      if (NewVD == 0) return 0;
844    }
845    New = NewVD;
846  }
847
848  // If this has an identifier, add it to the scope stack.
849  if (II)
850    PushOnScopeChains(New, S);
851  // If any semantic error occurred, mark the decl as invalid.
852  if (D.getInvalidType() || InvalidDecl)
853    New->setInvalidDecl();
854
855  return New;
856}
857
858bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) {
859  switch (Init->getStmtClass()) {
860  default:
861    Diag(Init->getExprLoc(),
862         diag::err_init_element_not_constant, Init->getSourceRange());
863    return true;
864  case Expr::ParenExprClass: {
865    const ParenExpr* PE = cast<ParenExpr>(Init);
866    return CheckAddressConstantExpressionLValue(PE->getSubExpr());
867  }
868  case Expr::CompoundLiteralExprClass:
869    return cast<CompoundLiteralExpr>(Init)->isFileScope();
870  case Expr::DeclRefExprClass: {
871    const Decl *D = cast<DeclRefExpr>(Init)->getDecl();
872    if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
873      if (VD->hasGlobalStorage())
874        return false;
875      Diag(Init->getExprLoc(),
876           diag::err_init_element_not_constant, Init->getSourceRange());
877      return true;
878    }
879    if (isa<FunctionDecl>(D))
880      return false;
881    Diag(Init->getExprLoc(),
882         diag::err_init_element_not_constant, Init->getSourceRange());
883    return true;
884  }
885  case Expr::MemberExprClass: {
886    const MemberExpr *M = cast<MemberExpr>(Init);
887    if (M->isArrow())
888      return CheckAddressConstantExpression(M->getBase());
889    return CheckAddressConstantExpressionLValue(M->getBase());
890  }
891  case Expr::ArraySubscriptExprClass: {
892    // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)?
893    const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(Init);
894    return CheckAddressConstantExpression(ASE->getBase()) ||
895           CheckArithmeticConstantExpression(ASE->getIdx());
896  }
897  case Expr::StringLiteralClass:
898  case Expr::PreDefinedExprClass:
899    return false;
900  case Expr::UnaryOperatorClass: {
901    const UnaryOperator *Exp = cast<UnaryOperator>(Init);
902
903    // C99 6.6p9
904    if (Exp->getOpcode() == UnaryOperator::Deref)
905      return CheckAddressConstantExpression(Exp->getSubExpr());
906
907    Diag(Init->getExprLoc(),
908         diag::err_init_element_not_constant, Init->getSourceRange());
909    return true;
910  }
911  }
912}
913
914bool Sema::CheckAddressConstantExpression(const Expr* Init) {
915  switch (Init->getStmtClass()) {
916  default:
917    Diag(Init->getExprLoc(),
918         diag::err_init_element_not_constant, Init->getSourceRange());
919    return true;
920  case Expr::ParenExprClass: {
921    const ParenExpr* PE = cast<ParenExpr>(Init);
922    return CheckAddressConstantExpression(PE->getSubExpr());
923  }
924  case Expr::StringLiteralClass:
925  case Expr::ObjCStringLiteralClass:
926    return false;
927  case Expr::CallExprClass: {
928    const CallExpr *CE = cast<CallExpr>(Init);
929    if (CE->isBuiltinConstantExpr())
930      return false;
931    Diag(Init->getExprLoc(),
932         diag::err_init_element_not_constant, Init->getSourceRange());
933    return true;
934  }
935  case Expr::UnaryOperatorClass: {
936    const UnaryOperator *Exp = cast<UnaryOperator>(Init);
937
938    // C99 6.6p9
939    if (Exp->getOpcode() == UnaryOperator::AddrOf)
940      return CheckAddressConstantExpressionLValue(Exp->getSubExpr());
941
942    if (Exp->getOpcode() == UnaryOperator::Extension)
943      return CheckAddressConstantExpression(Exp->getSubExpr());
944
945    Diag(Init->getExprLoc(),
946         diag::err_init_element_not_constant, Init->getSourceRange());
947    return true;
948  }
949  case Expr::BinaryOperatorClass: {
950    // FIXME: Should we pedwarn for expressions like "a + 1 + 2"?
951    const BinaryOperator *Exp = cast<BinaryOperator>(Init);
952
953    Expr *PExp = Exp->getLHS();
954    Expr *IExp = Exp->getRHS();
955    if (IExp->getType()->isPointerType())
956      std::swap(PExp, IExp);
957
958    // FIXME: Should we pedwarn if IExp isn't an integer constant expression?
959    return CheckAddressConstantExpression(PExp) ||
960           CheckArithmeticConstantExpression(IExp);
961  }
962  case Expr::ImplicitCastExprClass: {
963    const Expr* SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr();
964
965    // Check for implicit promotion
966    if (SubExpr->getType()->isFunctionType() ||
967        SubExpr->getType()->isArrayType())
968      return CheckAddressConstantExpressionLValue(SubExpr);
969
970    // Check for pointer->pointer cast
971    if (SubExpr->getType()->isPointerType())
972      return CheckAddressConstantExpression(SubExpr);
973
974    if (SubExpr->getType()->isArithmeticType())
975      return CheckArithmeticConstantExpression(SubExpr);
976
977    Diag(Init->getExprLoc(),
978         diag::err_init_element_not_constant, Init->getSourceRange());
979    return true;
980  }
981  case Expr::CastExprClass: {
982    const Expr* SubExpr = cast<CastExpr>(Init)->getSubExpr();
983
984    // Check for pointer->pointer cast
985    if (SubExpr->getType()->isPointerType())
986      return CheckAddressConstantExpression(SubExpr);
987
988    // FIXME: Should we pedwarn for (int*)(0+0)?
989    if (SubExpr->getType()->isArithmeticType())
990      return CheckArithmeticConstantExpression(SubExpr);
991
992    Diag(Init->getExprLoc(),
993         diag::err_init_element_not_constant, Init->getSourceRange());
994    return true;
995  }
996  case Expr::ConditionalOperatorClass: {
997    // FIXME: Should we pedwarn here?
998    const ConditionalOperator *Exp = cast<ConditionalOperator>(Init);
999    if (!Exp->getCond()->getType()->isArithmeticType()) {
1000      Diag(Init->getExprLoc(),
1001           diag::err_init_element_not_constant, Init->getSourceRange());
1002      return true;
1003    }
1004    if (CheckArithmeticConstantExpression(Exp->getCond()))
1005      return true;
1006    if (Exp->getLHS() &&
1007        CheckAddressConstantExpression(Exp->getLHS()))
1008      return true;
1009    return CheckAddressConstantExpression(Exp->getRHS());
1010  }
1011  case Expr::AddrLabelExprClass:
1012    return false;
1013  }
1014}
1015
1016static const Expr* FindExpressionBaseAddress(const Expr* E);
1017
1018static const Expr* FindExpressionBaseAddressLValue(const Expr* E) {
1019  switch (E->getStmtClass()) {
1020  default:
1021    return E;
1022  case Expr::ParenExprClass: {
1023    const ParenExpr* PE = cast<ParenExpr>(E);
1024    return FindExpressionBaseAddressLValue(PE->getSubExpr());
1025  }
1026  case Expr::MemberExprClass: {
1027    const MemberExpr *M = cast<MemberExpr>(E);
1028    if (M->isArrow())
1029      return FindExpressionBaseAddress(M->getBase());
1030    return FindExpressionBaseAddressLValue(M->getBase());
1031  }
1032  case Expr::ArraySubscriptExprClass: {
1033    const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E);
1034    return FindExpressionBaseAddress(ASE->getBase());
1035  }
1036  case Expr::UnaryOperatorClass: {
1037    const UnaryOperator *Exp = cast<UnaryOperator>(E);
1038
1039    if (Exp->getOpcode() == UnaryOperator::Deref)
1040      return FindExpressionBaseAddress(Exp->getSubExpr());
1041
1042    return E;
1043  }
1044  }
1045}
1046
1047static const Expr* FindExpressionBaseAddress(const Expr* E) {
1048  switch (E->getStmtClass()) {
1049  default:
1050    return E;
1051  case Expr::ParenExprClass: {
1052    const ParenExpr* PE = cast<ParenExpr>(E);
1053    return FindExpressionBaseAddress(PE->getSubExpr());
1054  }
1055  case Expr::UnaryOperatorClass: {
1056    const UnaryOperator *Exp = cast<UnaryOperator>(E);
1057
1058    // C99 6.6p9
1059    if (Exp->getOpcode() == UnaryOperator::AddrOf)
1060      return FindExpressionBaseAddressLValue(Exp->getSubExpr());
1061
1062    if (Exp->getOpcode() == UnaryOperator::Extension)
1063      return FindExpressionBaseAddress(Exp->getSubExpr());
1064
1065    return E;
1066  }
1067  case Expr::BinaryOperatorClass: {
1068    const BinaryOperator *Exp = cast<BinaryOperator>(E);
1069
1070    Expr *PExp = Exp->getLHS();
1071    Expr *IExp = Exp->getRHS();
1072    if (IExp->getType()->isPointerType())
1073      std::swap(PExp, IExp);
1074
1075    return FindExpressionBaseAddress(PExp);
1076  }
1077  case Expr::ImplicitCastExprClass: {
1078    const Expr* SubExpr = cast<ImplicitCastExpr>(E)->getSubExpr();
1079
1080    // Check for implicit promotion
1081    if (SubExpr->getType()->isFunctionType() ||
1082        SubExpr->getType()->isArrayType())
1083      return FindExpressionBaseAddressLValue(SubExpr);
1084
1085    // Check for pointer->pointer cast
1086    if (SubExpr->getType()->isPointerType())
1087      return FindExpressionBaseAddress(SubExpr);
1088
1089    // We assume that we have an arithmetic expression here;
1090    // if we don't, we'll figure it out later
1091    return 0;
1092  }
1093  case Expr::CastExprClass: {
1094    const Expr* SubExpr = cast<CastExpr>(E)->getSubExpr();
1095
1096    // Check for pointer->pointer cast
1097    if (SubExpr->getType()->isPointerType())
1098      return FindExpressionBaseAddress(SubExpr);
1099
1100    // We assume that we have an arithmetic expression here;
1101    // if we don't, we'll figure it out later
1102    return 0;
1103  }
1104  }
1105}
1106
1107bool Sema::CheckArithmeticConstantExpression(const Expr* Init) {
1108  switch (Init->getStmtClass()) {
1109  default:
1110    Diag(Init->getExprLoc(),
1111         diag::err_init_element_not_constant, Init->getSourceRange());
1112    return true;
1113  case Expr::ParenExprClass: {
1114    const ParenExpr* PE = cast<ParenExpr>(Init);
1115    return CheckArithmeticConstantExpression(PE->getSubExpr());
1116  }
1117  case Expr::FloatingLiteralClass:
1118  case Expr::IntegerLiteralClass:
1119  case Expr::CharacterLiteralClass:
1120  case Expr::ImaginaryLiteralClass:
1121  case Expr::TypesCompatibleExprClass:
1122  case Expr::CXXBoolLiteralExprClass:
1123    return false;
1124  case Expr::CallExprClass: {
1125    const CallExpr *CE = cast<CallExpr>(Init);
1126    if (CE->isBuiltinConstantExpr())
1127      return false;
1128    Diag(Init->getExprLoc(),
1129         diag::err_init_element_not_constant, Init->getSourceRange());
1130    return true;
1131  }
1132  case Expr::DeclRefExprClass: {
1133    const Decl *D = cast<DeclRefExpr>(Init)->getDecl();
1134    if (isa<EnumConstantDecl>(D))
1135      return false;
1136    Diag(Init->getExprLoc(),
1137         diag::err_init_element_not_constant, Init->getSourceRange());
1138    return true;
1139  }
1140  case Expr::CompoundLiteralExprClass:
1141    // Allow "(vector type){2,4}"; normal C constraints don't allow this,
1142    // but vectors are allowed to be magic.
1143    if (Init->getType()->isVectorType())
1144      return false;
1145    Diag(Init->getExprLoc(),
1146         diag::err_init_element_not_constant, Init->getSourceRange());
1147    return true;
1148  case Expr::UnaryOperatorClass: {
1149    const UnaryOperator *Exp = cast<UnaryOperator>(Init);
1150
1151    switch (Exp->getOpcode()) {
1152    // Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
1153    // See C99 6.6p3.
1154    default:
1155      Diag(Init->getExprLoc(),
1156           diag::err_init_element_not_constant, Init->getSourceRange());
1157      return true;
1158    case UnaryOperator::SizeOf:
1159    case UnaryOperator::AlignOf:
1160    case UnaryOperator::OffsetOf:
1161      // sizeof(E) is a constantexpr if and only if E is not evaluted.
1162      // See C99 6.5.3.4p2 and 6.6p3.
1163      if (Exp->getSubExpr()->getType()->isConstantSizeType())
1164        return false;
1165      Diag(Init->getExprLoc(),
1166           diag::err_init_element_not_constant, Init->getSourceRange());
1167      return true;
1168    case UnaryOperator::Extension:
1169    case UnaryOperator::LNot:
1170    case UnaryOperator::Plus:
1171    case UnaryOperator::Minus:
1172    case UnaryOperator::Not:
1173      return CheckArithmeticConstantExpression(Exp->getSubExpr());
1174    }
1175  }
1176  case Expr::SizeOfAlignOfTypeExprClass: {
1177    const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(Init);
1178    // Special check for void types, which are allowed as an extension
1179    if (Exp->getArgumentType()->isVoidType())
1180      return false;
1181    // alignof always evaluates to a constant.
1182    // FIXME: is sizeof(int[3.0]) a constant expression?
1183    if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) {
1184      Diag(Init->getExprLoc(),
1185           diag::err_init_element_not_constant, Init->getSourceRange());
1186      return true;
1187    }
1188    return false;
1189  }
1190  case Expr::BinaryOperatorClass: {
1191    const BinaryOperator *Exp = cast<BinaryOperator>(Init);
1192
1193    if (Exp->getLHS()->getType()->isArithmeticType() &&
1194        Exp->getRHS()->getType()->isArithmeticType()) {
1195      return CheckArithmeticConstantExpression(Exp->getLHS()) ||
1196             CheckArithmeticConstantExpression(Exp->getRHS());
1197    }
1198
1199    if (Exp->getLHS()->getType()->isPointerType() &&
1200        Exp->getRHS()->getType()->isPointerType()) {
1201      const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS());
1202      const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS());
1203
1204      // Only allow a null (constant integer) base; we could
1205      // allow some additional cases if necessary, but this
1206      // is sufficient to cover offsetof-like constructs.
1207      if (!LHSBase && !RHSBase) {
1208        return CheckAddressConstantExpression(Exp->getLHS()) ||
1209               CheckAddressConstantExpression(Exp->getRHS());
1210      }
1211    }
1212
1213    Diag(Init->getExprLoc(),
1214         diag::err_init_element_not_constant, Init->getSourceRange());
1215    return true;
1216  }
1217  case Expr::ImplicitCastExprClass:
1218  case Expr::CastExprClass: {
1219    const Expr *SubExpr;
1220    if (const CastExpr *C = dyn_cast<CastExpr>(Init)) {
1221      SubExpr = C->getSubExpr();
1222    } else {
1223      SubExpr = cast<ImplicitCastExpr>(Init)->getSubExpr();
1224    }
1225
1226    if (SubExpr->getType()->isArithmeticType())
1227      return CheckArithmeticConstantExpression(SubExpr);
1228
1229    Diag(Init->getExprLoc(),
1230         diag::err_init_element_not_constant, Init->getSourceRange());
1231    return true;
1232  }
1233  case Expr::ConditionalOperatorClass: {
1234    const ConditionalOperator *Exp = cast<ConditionalOperator>(Init);
1235    if (CheckArithmeticConstantExpression(Exp->getCond()))
1236      return true;
1237    if (Exp->getLHS() &&
1238        CheckArithmeticConstantExpression(Exp->getLHS()))
1239      return true;
1240    return CheckArithmeticConstantExpression(Exp->getRHS());
1241  }
1242  }
1243}
1244
1245bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) {
1246  Init = Init->IgnoreParens();
1247
1248  // Look through CXXDefaultArgExprs; they have no meaning in this context.
1249  if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init))
1250    return CheckForConstantInitializer(DAE->getExpr(), DclT);
1251
1252  if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init))
1253    return CheckForConstantInitializer(e->getInitializer(), DclT);
1254
1255  if (Init->getType()->isReferenceType()) {
1256    // FIXME: Work out how the heck reference types work
1257    return false;
1258#if 0
1259    // A reference is constant if the address of the expression
1260    // is constant
1261    // We look through initlists here to simplify
1262    // CheckAddressConstantExpressionLValue.
1263    if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) {
1264      assert(Exp->getNumInits() > 0 &&
1265             "Refernce initializer cannot be empty");
1266      Init = Exp->getInit(0);
1267    }
1268    return CheckAddressConstantExpressionLValue(Init);
1269#endif
1270  }
1271
1272  if (InitListExpr *Exp = dyn_cast<InitListExpr>(Init)) {
1273    unsigned numInits = Exp->getNumInits();
1274    for (unsigned i = 0; i < numInits; i++) {
1275      // FIXME: Need to get the type of the declaration for C++,
1276      // because it could be a reference?
1277      if (CheckForConstantInitializer(Exp->getInit(i),
1278                                      Exp->getInit(i)->getType()))
1279        return true;
1280    }
1281    return false;
1282  }
1283
1284  if (Init->isNullPointerConstant(Context))
1285    return false;
1286  if (Init->getType()->isArithmeticType()) {
1287    QualType InitTy = Context.getCanonicalType(Init->getType())
1288                             .getUnqualifiedType();
1289    if (InitTy == Context.BoolTy) {
1290      // Special handling for pointers implicitly cast to bool;
1291      // (e.g. "_Bool rr = &rr;"). This is only legal at the top level.
1292      if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init)) {
1293        Expr* SubE = ICE->getSubExpr();
1294        if (SubE->getType()->isPointerType() ||
1295            SubE->getType()->isArrayType() ||
1296            SubE->getType()->isFunctionType()) {
1297          return CheckAddressConstantExpression(Init);
1298        }
1299      }
1300    } else if (InitTy->isIntegralType()) {
1301      Expr* SubE = 0;
1302      if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Init))
1303        SubE = ICE->getSubExpr();
1304      else if (CastExpr* CE = dyn_cast<CastExpr>(Init))
1305        SubE = CE->getSubExpr();
1306      // Special check for pointer cast to int; we allow as an extension
1307      // an address constant cast to an integer if the integer
1308      // is of an appropriate width (this sort of code is apparently used
1309      // in some places).
1310      // FIXME: Add pedwarn?
1311      // FIXME: Don't allow bitfields here!  Need the FieldDecl for that.
1312      if (SubE && (SubE->getType()->isPointerType() ||
1313                   SubE->getType()->isArrayType() ||
1314                   SubE->getType()->isFunctionType())) {
1315        unsigned IntWidth = Context.getTypeSize(Init->getType());
1316        unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy);
1317        if (IntWidth >= PointerWidth)
1318          return CheckAddressConstantExpression(Init);
1319      }
1320    }
1321
1322    return CheckArithmeticConstantExpression(Init);
1323  }
1324
1325  if (Init->getType()->isPointerType())
1326    return CheckAddressConstantExpression(Init);
1327
1328  // An array type at the top level that isn't an init-list must
1329  // be a string literal
1330  if (Init->getType()->isArrayType())
1331    return false;
1332
1333  Diag(Init->getExprLoc(), diag::err_init_element_not_constant,
1334       Init->getSourceRange());
1335  return true;
1336}
1337
1338void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) {
1339  Decl *RealDecl = static_cast<Decl *>(dcl);
1340  Expr *Init = static_cast<Expr *>(init);
1341  assert(Init && "missing initializer");
1342
1343  // If there is no declaration, there was an error parsing it.  Just ignore
1344  // the initializer.
1345  if (RealDecl == 0) {
1346    delete Init;
1347    return;
1348  }
1349
1350  VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl);
1351  if (!VDecl) {
1352    Diag(dyn_cast<ScopedDecl>(RealDecl)->getLocation(),
1353         diag::err_illegal_initializer);
1354    RealDecl->setInvalidDecl();
1355    return;
1356  }
1357  // Get the decls type and save a reference for later, since
1358  // CheckInitializerTypes may change it.
1359  QualType DclT = VDecl->getType(), SavT = DclT;
1360  if (VDecl->isBlockVarDecl()) {
1361    VarDecl::StorageClass SC = VDecl->getStorageClass();
1362    if (SC == VarDecl::Extern) { // C99 6.7.8p5
1363      Diag(VDecl->getLocation(), diag::err_block_extern_cant_init);
1364      VDecl->setInvalidDecl();
1365    } else if (!VDecl->isInvalidDecl()) {
1366      if (CheckInitializerTypes(Init, DclT))
1367        VDecl->setInvalidDecl();
1368      if (SC == VarDecl::Static) // C99 6.7.8p4.
1369        CheckForConstantInitializer(Init, DclT);
1370    }
1371  } else if (VDecl->isFileVarDecl()) {
1372    if (VDecl->getStorageClass() == VarDecl::Extern)
1373      Diag(VDecl->getLocation(), diag::warn_extern_init);
1374    if (!VDecl->isInvalidDecl())
1375      if (CheckInitializerTypes(Init, DclT))
1376        VDecl->setInvalidDecl();
1377
1378    // C99 6.7.8p4. All file scoped initializers need to be constant.
1379    CheckForConstantInitializer(Init, DclT);
1380  }
1381  // If the type changed, it means we had an incomplete type that was
1382  // completed by the initializer. For example:
1383  //   int ary[] = { 1, 3, 5 };
1384  // "ary" transitions from a VariableArrayType to a ConstantArrayType.
1385  if (!VDecl->isInvalidDecl() && (DclT != SavT)) {
1386    VDecl->setType(DclT);
1387    Init->setType(DclT);
1388  }
1389
1390  // Attach the initializer to the decl.
1391  VDecl->setInit(Init);
1392  return;
1393}
1394
1395/// The declarators are chained together backwards, reverse the list.
1396Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) {
1397  // Often we have single declarators, handle them quickly.
1398  Decl *GroupDecl = static_cast<Decl*>(group);
1399  if (GroupDecl == 0)
1400    return 0;
1401
1402  ScopedDecl *Group = dyn_cast<ScopedDecl>(GroupDecl);
1403  ScopedDecl *NewGroup = 0;
1404  if (Group->getNextDeclarator() == 0)
1405    NewGroup = Group;
1406  else { // reverse the list.
1407    while (Group) {
1408      ScopedDecl *Next = Group->getNextDeclarator();
1409      Group->setNextDeclarator(NewGroup);
1410      NewGroup = Group;
1411      Group = Next;
1412    }
1413  }
1414  // Perform semantic analysis that depends on having fully processed both
1415  // the declarator and initializer.
1416  for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) {
1417    VarDecl *IDecl = dyn_cast<VarDecl>(ID);
1418    if (!IDecl)
1419      continue;
1420    QualType T = IDecl->getType();
1421
1422    // C99 6.7.5.2p2: If an identifier is declared to be an object with
1423    // static storage duration, it shall not have a variable length array.
1424    if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) &&
1425        IDecl->getStorageClass() == VarDecl::Static) {
1426      if (T->isVariableArrayType()) {
1427        Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla);
1428        IDecl->setInvalidDecl();
1429      }
1430    }
1431    // Block scope. C99 6.7p7: If an identifier for an object is declared with
1432    // no linkage (C99 6.2.2p6), the type for the object shall be complete...
1433    if (IDecl->isBlockVarDecl() &&
1434        IDecl->getStorageClass() != VarDecl::Extern) {
1435      if (T->isIncompleteType() && !IDecl->isInvalidDecl()) {
1436        Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type,
1437             T.getAsString());
1438        IDecl->setInvalidDecl();
1439      }
1440    }
1441    // File scope. C99 6.9.2p2: A declaration of an identifier for and
1442    // object that has file scope without an initializer, and without a
1443    // storage-class specifier or with the storage-class specifier "static",
1444    // constitutes a tentative definition. Note: A tentative definition with
1445    // external linkage is valid (C99 6.2.2p5).
1446    if (isTentativeDefinition(IDecl)) {
1447      if (T->isIncompleteArrayType()) {
1448        // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete
1449        // array to be completed. Don't issue a diagnostic.
1450      } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) {
1451        // C99 6.9.2p3: If the declaration of an identifier for an object is
1452        // a tentative definition and has internal linkage (C99 6.2.2p3), the
1453        // declared type shall not be an incomplete type.
1454        Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type,
1455             T.getAsString());
1456        IDecl->setInvalidDecl();
1457      }
1458    }
1459    if (IDecl->isFileVarDecl())
1460      CheckForFileScopedRedefinitions(S, IDecl);
1461  }
1462  return NewGroup;
1463}
1464
1465/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator()
1466/// to introduce parameters into function prototype scope.
1467Sema::DeclTy *
1468Sema::ActOnParamDeclarator(Scope *S, Declarator &D) {
1469  const DeclSpec &DS = D.getDeclSpec();
1470
1471  // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'.
1472  if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
1473      DS.getStorageClassSpec() != DeclSpec::SCS_register) {
1474    Diag(DS.getStorageClassSpecLoc(),
1475         diag::err_invalid_storage_class_in_func_decl);
1476    D.getMutableDeclSpec().ClearStorageClassSpecs();
1477  }
1478  if (DS.isThreadSpecified()) {
1479    Diag(DS.getThreadSpecLoc(),
1480         diag::err_invalid_storage_class_in_func_decl);
1481    D.getMutableDeclSpec().ClearStorageClassSpecs();
1482  }
1483
1484  // Check that there are no default arguments inside the type of this
1485  // parameter (C++ only).
1486  if (getLangOptions().CPlusPlus)
1487    CheckExtraCXXDefaultArguments(D);
1488
1489  // In this context, we *do not* check D.getInvalidType(). If the declarator
1490  // type was invalid, GetTypeForDeclarator() still returns a "valid" type,
1491  // though it will not reflect the user specified type.
1492  QualType parmDeclType = GetTypeForDeclarator(D, S);
1493
1494  assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type");
1495
1496  // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
1497  // Can this happen for params?  We already checked that they don't conflict
1498  // among each other.  Here they can only shadow globals, which is ok.
1499  IdentifierInfo *II = D.getIdentifier();
1500  if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) {
1501    if (S->isDeclScope(PrevDecl)) {
1502      Diag(D.getIdentifierLoc(), diag::err_param_redefinition,
1503           dyn_cast<NamedDecl>(PrevDecl)->getName());
1504
1505      // Recover by removing the name
1506      II = 0;
1507      D.SetIdentifier(0, D.getIdentifierLoc());
1508    }
1509  }
1510
1511  // Perform the default function/array conversion (C99 6.7.5.3p[7,8]).
1512  // Doing the promotion here has a win and a loss. The win is the type for
1513  // both Decl's and DeclRefExpr's will match (a convenient invariant for the
1514  // code generator). The loss is the orginal type isn't preserved. For example:
1515  //
1516  // void func(int parmvardecl[5]) { // convert "int [5]" to "int *"
1517  //    int blockvardecl[5];
1518  //    sizeof(parmvardecl);  // size == 4
1519  //    sizeof(blockvardecl); // size == 20
1520  // }
1521  //
1522  // For expressions, all implicit conversions are captured using the
1523  // ImplicitCastExpr AST node (we have no such mechanism for Decl's).
1524  //
1525  // FIXME: If a source translation tool needs to see the original type, then
1526  // we need to consider storing both types (in ParmVarDecl)...
1527  //
1528  if (parmDeclType->isArrayType()) {
1529    // int x[restrict 4] ->  int *restrict
1530    parmDeclType = Context.getArrayDecayedType(parmDeclType);
1531  } else if (parmDeclType->isFunctionType())
1532    parmDeclType = Context.getPointerType(parmDeclType);
1533
1534  ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext,
1535                                         D.getIdentifierLoc(), II,
1536                                         parmDeclType, VarDecl::None,
1537                                         0, 0);
1538
1539  if (D.getInvalidType())
1540    New->setInvalidDecl();
1541
1542  if (II)
1543    PushOnScopeChains(New, S);
1544
1545  ProcessDeclAttributes(New, D);
1546  return New;
1547
1548}
1549
1550Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) {
1551  assert(getCurFunctionDecl() == 0 && "Function parsing confused");
1552  assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function &&
1553         "Not a function declarator!");
1554  DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
1555
1556  // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared'
1557  // for a K&R function.
1558  if (!FTI.hasPrototype) {
1559    for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) {
1560      if (FTI.ArgInfo[i].Param == 0) {
1561        Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared,
1562             FTI.ArgInfo[i].Ident->getName());
1563        // Implicitly declare the argument as type 'int' for lack of a better
1564        // type.
1565        DeclSpec DS;
1566        const char* PrevSpec; // unused
1567        DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc,
1568                           PrevSpec);
1569        Declarator ParamD(DS, Declarator::KNRTypeListContext);
1570        ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc);
1571        FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD);
1572      }
1573    }
1574
1575    // Since this is a function definition, act as though we have information
1576    // about the arguments.
1577    if (FTI.NumArgs)
1578      FTI.hasPrototype = true;
1579  } else {
1580    // FIXME: Diagnose arguments without names in C.
1581  }
1582
1583  Scope *GlobalScope = FnBodyScope->getParent();
1584
1585  // See if this is a redefinition.
1586  Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary,
1587                             GlobalScope);
1588  if (PrevDcl && IdResolver.isDeclInScope(PrevDcl, CurContext)) {
1589    if (FunctionDecl *FD = dyn_cast<FunctionDecl>(PrevDcl)) {
1590      const FunctionDecl *Definition;
1591      if (FD->getBody(Definition)) {
1592        Diag(D.getIdentifierLoc(), diag::err_redefinition,
1593             D.getIdentifier()->getName());
1594        Diag(Definition->getLocation(), diag::err_previous_definition);
1595      }
1596    }
1597  }
1598
1599  return ActOnStartOfFunctionDef(FnBodyScope,
1600                                 ActOnDeclarator(GlobalScope, D, 0));
1601}
1602
1603Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) {
1604  Decl *decl = static_cast<Decl*>(D);
1605  FunctionDecl *FD = cast<FunctionDecl>(decl);
1606  PushDeclContext(FD);
1607
1608  // Check the validity of our function parameters
1609  CheckParmsForFunctionDef(FD);
1610
1611  // Introduce our parameters into the function scope
1612  for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) {
1613    ParmVarDecl *Param = FD->getParamDecl(p);
1614    // If this has an identifier, add it to the scope stack.
1615    if (Param->getIdentifier())
1616      PushOnScopeChains(Param, FnBodyScope);
1617  }
1618
1619  return FD;
1620}
1621
1622Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) {
1623  Decl *dcl = static_cast<Decl *>(D);
1624  if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) {
1625    FD->setBody((Stmt*)Body);
1626    assert(FD == getCurFunctionDecl() && "Function parsing confused");
1627  } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) {
1628    MD->setBody((Stmt*)Body);
1629  } else
1630    return 0;
1631  PopDeclContext();
1632  // Verify and clean out per-function state.
1633
1634  // Check goto/label use.
1635  for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator
1636       I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) {
1637    // Verify that we have no forward references left.  If so, there was a goto
1638    // or address of a label taken, but no definition of it.  Label fwd
1639    // definitions are indicated with a null substmt.
1640    if (I->second->getSubStmt() == 0) {
1641      LabelStmt *L = I->second;
1642      // Emit error.
1643      Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName());
1644
1645      // At this point, we have gotos that use the bogus label.  Stitch it into
1646      // the function body so that they aren't leaked and that the AST is well
1647      // formed.
1648      if (Body) {
1649        L->setSubStmt(new NullStmt(L->getIdentLoc()));
1650        cast<CompoundStmt>((Stmt*)Body)->push_back(L);
1651      } else {
1652        // The whole function wasn't parsed correctly, just delete this.
1653        delete L;
1654      }
1655    }
1656  }
1657  LabelMap.clear();
1658
1659  return D;
1660}
1661
1662/// ImplicitlyDefineFunction - An undeclared identifier was used in a function
1663/// call, forming a call to an implicitly defined function (per C99 6.5.1p2).
1664ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc,
1665                                           IdentifierInfo &II, Scope *S) {
1666  // Extension in C99.  Legal in C90, but warn about it.
1667  if (getLangOptions().C99)
1668    Diag(Loc, diag::ext_implicit_function_decl, II.getName());
1669  else
1670    Diag(Loc, diag::warn_implicit_function_decl, II.getName());
1671
1672  // FIXME: handle stuff like:
1673  // void foo() { extern float X(); }
1674  // void bar() { X(); }  <-- implicit decl for X in another scope.
1675
1676  // Set a Declarator for the implicit definition: int foo();
1677  const char *Dummy;
1678  DeclSpec DS;
1679  bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy);
1680  Error = Error; // Silence warning.
1681  assert(!Error && "Error setting up implicit decl!");
1682  Declarator D(DS, Declarator::BlockContext);
1683  D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc));
1684  D.SetIdentifier(&II, Loc);
1685
1686  // Insert this function into translation-unit scope.
1687
1688  DeclContext *PrevDC = CurContext;
1689  CurContext = Context.getTranslationUnitDecl();
1690
1691  FunctionDecl *FD =
1692    dyn_cast<FunctionDecl>(static_cast<Decl*>(ActOnDeclarator(TUScope, D, 0)));
1693  FD->setImplicit();
1694
1695  CurContext = PrevDC;
1696
1697  return FD;
1698}
1699
1700
1701TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T,
1702                                    ScopedDecl *LastDeclarator) {
1703  assert(D.getIdentifier() && "Wrong callback for declspec without declarator");
1704  assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
1705
1706  // Scope manipulation handled by caller.
1707  TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext,
1708                                           D.getIdentifierLoc(),
1709                                           D.getIdentifier(),
1710                                           T, LastDeclarator);
1711  if (D.getInvalidType())
1712    NewTD->setInvalidDecl();
1713  return NewTD;
1714}
1715
1716/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'.  In the
1717/// former case, Name will be non-null.  In the later case, Name will be null.
1718/// TagType indicates what kind of tag this is. TK indicates whether this is a
1719/// reference/declaration/definition of a tag.
1720Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK,
1721                             SourceLocation KWLoc, IdentifierInfo *Name,
1722                             SourceLocation NameLoc, AttributeList *Attr) {
1723  // If this is a use of an existing tag, it must have a name.
1724  assert((Name != 0 || TK == TK_Definition) &&
1725         "Nameless record must be a definition!");
1726
1727  TagDecl::TagKind Kind;
1728  switch (TagType) {
1729  default: assert(0 && "Unknown tag type!");
1730  case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break;
1731  case DeclSpec::TST_union:  Kind = TagDecl::TK_union; break;
1732  case DeclSpec::TST_class:  Kind = TagDecl::TK_class; break;
1733  case DeclSpec::TST_enum:   Kind = TagDecl::TK_enum; break;
1734  }
1735
1736  // If this is a named struct, check to see if there was a previous forward
1737  // declaration or definition.
1738  // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up.
1739  if (ScopedDecl *PrevDecl =
1740          dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag, S))) {
1741
1742    assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) &&
1743            "unexpected Decl type");
1744    if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) {
1745      // If this is a use of a previous tag, or if the tag is already declared
1746      // in the same scope (so that the definition/declaration completes or
1747      // rementions the tag), reuse the decl.
1748      if (TK == TK_Reference ||
1749          IdResolver.isDeclInScope(PrevDecl, CurContext, S)) {
1750        // Make sure that this wasn't declared as an enum and now used as a
1751        // struct or something similar.
1752        if (PrevTagDecl->getTagKind() != Kind) {
1753          Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName());
1754          Diag(PrevDecl->getLocation(), diag::err_previous_use);
1755          // Recover by making this an anonymous redefinition.
1756          Name = 0;
1757          PrevDecl = 0;
1758        } else {
1759          // If this is a use or a forward declaration, we're good.
1760          if (TK != TK_Definition)
1761            return PrevDecl;
1762
1763          // Diagnose attempts to redefine a tag.
1764          if (PrevTagDecl->isDefinition()) {
1765            Diag(NameLoc, diag::err_redefinition, Name->getName());
1766            Diag(PrevDecl->getLocation(), diag::err_previous_definition);
1767            // If this is a redefinition, recover by making this struct be
1768            // anonymous, which will make any later references get the previous
1769            // definition.
1770            Name = 0;
1771          } else {
1772            // Okay, this is definition of a previously declared or referenced
1773            // tag. Move the location of the decl to be the definition site.
1774            PrevDecl->setLocation(NameLoc);
1775            return PrevDecl;
1776          }
1777        }
1778      }
1779      // If we get here, this is a definition of a new struct type in a nested
1780      // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new
1781      // type.
1782    } else {
1783      // PrevDecl is a namespace.
1784      if (IdResolver.isDeclInScope(PrevDecl, CurContext, S)) {
1785        // The tag name clashes with a namespace name, issue an error and recover
1786        // by making this tag be anonymous.
1787        Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName());
1788        Diag(PrevDecl->getLocation(), diag::err_previous_definition);
1789        Name = 0;
1790      }
1791    }
1792  }
1793
1794  // If there is an identifier, use the location of the identifier as the
1795  // location of the decl, otherwise use the location of the struct/union
1796  // keyword.
1797  SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
1798
1799  // Otherwise, if this is the first time we've seen this tag, create the decl.
1800  TagDecl *New;
1801  if (Kind == TagDecl::TK_enum) {
1802    // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
1803    // enum X { A, B, C } D;    D should chain to X.
1804    New = EnumDecl::Create(Context, CurContext, Loc, Name, 0);
1805    // If this is an undefined enum, warn.
1806    if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum);
1807  } else {
1808    // struct/union/class
1809
1810    // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
1811    // struct X { int A; } D;    D should chain to X.
1812    if (getLangOptions().CPlusPlus)
1813      // FIXME: Look for a way to use RecordDecl for simple structs.
1814      New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0);
1815    else
1816      New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, 0);
1817  }
1818
1819  // If this has an identifier, add it to the scope stack.
1820  if (Name) {
1821    // The scope passed in may not be a decl scope.  Zip up the scope tree until
1822    // we find one that is.
1823    while ((S->getFlags() & Scope::DeclScope) == 0)
1824      S = S->getParent();
1825
1826    // Add it to the decl chain.
1827    PushOnScopeChains(New, S);
1828  }
1829
1830  if (Attr)
1831    ProcessDeclAttributeList(New, Attr);
1832  return New;
1833}
1834
1835/// Collect the instance variables declared in an Objective-C object.  Used in
1836/// the creation of structures from objects using the @defs directive.
1837static void CollectIvars(ObjCInterfaceDecl *Class,
1838                         llvm::SmallVectorImpl<Sema::DeclTy*> &ivars) {
1839  if (Class->getSuperClass())
1840    CollectIvars(Class->getSuperClass(), ivars);
1841  ivars.append(Class->ivar_begin(), Class->ivar_end());
1842}
1843
1844/// Called whenever @defs(ClassName) is encountered in the source.  Inserts the
1845/// instance variables of ClassName into Decls.
1846void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart,
1847                     IdentifierInfo *ClassName,
1848                     llvm::SmallVectorImpl<DeclTy*> &Decls) {
1849  // Check that ClassName is a valid class
1850  ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName);
1851  if (!Class) {
1852    Diag(DeclStart, diag::err_undef_interface, ClassName->getName());
1853    return;
1854  }
1855  // Collect the instance variables
1856  CollectIvars(Class, Decls);
1857}
1858
1859QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) {
1860  // This method tries to turn a variable array into a constant
1861  // array even when the size isn't an ICE.  This is necessary
1862  // for compatibility with code that depends on gcc's buggy
1863  // constant expression folding, like struct {char x[(int)(char*)2];}
1864  if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) {
1865    APValue Result;
1866    if (VLATy->getSizeExpr() &&
1867        VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) {
1868      llvm::APSInt &Res = Result.getInt();
1869      if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned()))
1870        return Context.getConstantArrayType(VLATy->getElementType(),
1871                                            Res, ArrayType::Normal, 0);
1872    }
1873  }
1874  return QualType();
1875}
1876
1877/// ActOnField - Each field of a struct/union/class is passed into this in order
1878/// to create a FieldDecl object for it.
1879Sema::DeclTy *Sema::ActOnField(Scope *S,
1880                               SourceLocation DeclStart,
1881                               Declarator &D, ExprTy *BitfieldWidth) {
1882  IdentifierInfo *II = D.getIdentifier();
1883  Expr *BitWidth = (Expr*)BitfieldWidth;
1884  SourceLocation Loc = DeclStart;
1885  if (II) Loc = D.getIdentifierLoc();
1886
1887  // FIXME: Unnamed fields can be handled in various different ways, for
1888  // example, unnamed unions inject all members into the struct namespace!
1889
1890
1891  if (BitWidth) {
1892    // TODO: Validate.
1893    //printf("WARNING: BITFIELDS IGNORED!\n");
1894
1895    // 6.7.2.1p3
1896    // 6.7.2.1p4
1897
1898  } else {
1899    // Not a bitfield.
1900
1901    // validate II.
1902
1903  }
1904
1905  QualType T = GetTypeForDeclarator(D, S);
1906  assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
1907  bool InvalidDecl = false;
1908
1909  // C99 6.7.2.1p8: A member of a structure or union may have any type other
1910  // than a variably modified type.
1911  if (T->isVariablyModifiedType()) {
1912    QualType FixedTy = TryFixInvalidVariablyModifiedType(T);
1913    if (!FixedTy.isNull()) {
1914      Diag(Loc, diag::warn_illegal_constant_array_size, Loc);
1915      T = FixedTy;
1916    } else {
1917      // FIXME: This diagnostic needs work
1918      Diag(Loc, diag::err_typecheck_illegal_vla, Loc);
1919      InvalidDecl = true;
1920    }
1921  }
1922  // FIXME: Chain fielddecls together.
1923  FieldDecl *NewFD;
1924
1925  if (getLangOptions().CPlusPlus) {
1926    // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs.
1927    NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext),
1928                                 Loc, II, T, BitWidth);
1929    if (II)
1930      PushOnScopeChains(NewFD, S);
1931  }
1932  else
1933    NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth);
1934
1935  ProcessDeclAttributes(NewFD, D);
1936
1937  if (D.getInvalidType() || InvalidDecl)
1938    NewFD->setInvalidDecl();
1939  return NewFD;
1940}
1941
1942/// TranslateIvarVisibility - Translate visibility from a token ID to an
1943///  AST enum value.
1944static ObjCIvarDecl::AccessControl
1945TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) {
1946  switch (ivarVisibility) {
1947    case tok::objc_private: return ObjCIvarDecl::Private;
1948    case tok::objc_public: return ObjCIvarDecl::Public;
1949    case tok::objc_protected: return ObjCIvarDecl::Protected;
1950    case tok::objc_package: return ObjCIvarDecl::Package;
1951    default: assert(false && "Unknown visitibility kind");
1952  }
1953}
1954
1955/// ActOnIvar - Each ivar field of an objective-c class is passed into this
1956/// in order to create an IvarDecl object for it.
1957Sema::DeclTy *Sema::ActOnIvar(Scope *S,
1958                              SourceLocation DeclStart,
1959                              Declarator &D, ExprTy *BitfieldWidth,
1960                              tok::ObjCKeywordKind Visibility) {
1961  IdentifierInfo *II = D.getIdentifier();
1962  Expr *BitWidth = (Expr*)BitfieldWidth;
1963  SourceLocation Loc = DeclStart;
1964  if (II) Loc = D.getIdentifierLoc();
1965
1966  // FIXME: Unnamed fields can be handled in various different ways, for
1967  // example, unnamed unions inject all members into the struct namespace!
1968
1969
1970  if (BitWidth) {
1971    // TODO: Validate.
1972    //printf("WARNING: BITFIELDS IGNORED!\n");
1973
1974    // 6.7.2.1p3
1975    // 6.7.2.1p4
1976
1977  } else {
1978    // Not a bitfield.
1979
1980    // validate II.
1981
1982  }
1983
1984  QualType T = GetTypeForDeclarator(D, S);
1985  assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
1986  bool InvalidDecl = false;
1987
1988  // C99 6.7.2.1p8: A member of a structure or union may have any type other
1989  // than a variably modified type.
1990  if (T->isVariablyModifiedType()) {
1991    // FIXME: This diagnostic needs work
1992    Diag(Loc, diag::err_typecheck_illegal_vla, Loc);
1993    InvalidDecl = true;
1994  }
1995
1996  // Get the visibility (access control) for this ivar.
1997  ObjCIvarDecl::AccessControl ac =
1998    Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility)
1999                                        : ObjCIvarDecl::None;
2000
2001  // Construct the decl.
2002  ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac,
2003                                             (Expr *)BitfieldWidth);
2004
2005  // Process attributes attached to the ivar.
2006  ProcessDeclAttributes(NewID, D);
2007
2008  if (D.getInvalidType() || InvalidDecl)
2009    NewID->setInvalidDecl();
2010
2011  return NewID;
2012}
2013
2014void Sema::ActOnFields(Scope* S,
2015                       SourceLocation RecLoc, DeclTy *RecDecl,
2016                       DeclTy **Fields, unsigned NumFields,
2017                       SourceLocation LBrac, SourceLocation RBrac) {
2018  Decl *EnclosingDecl = static_cast<Decl*>(RecDecl);
2019  assert(EnclosingDecl && "missing record or interface decl");
2020  RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl);
2021
2022  if (Record && Record->isDefinition()) {
2023    // Diagnose code like:
2024    //     struct S { struct S {} X; };
2025    // We discover this when we complete the outer S.  Reject and ignore the
2026    // outer S.
2027    Diag(Record->getLocation(), diag::err_nested_redefinition,
2028         Record->getKindName());
2029    Diag(RecLoc, diag::err_previous_definition);
2030    Record->setInvalidDecl();
2031    return;
2032  }
2033  // Verify that all the fields are okay.
2034  unsigned NumNamedMembers = 0;
2035  llvm::SmallVector<FieldDecl*, 32> RecFields;
2036  llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs;
2037
2038  for (unsigned i = 0; i != NumFields; ++i) {
2039
2040    FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i]));
2041    assert(FD && "missing field decl");
2042
2043    // Remember all fields.
2044    RecFields.push_back(FD);
2045
2046    // Get the type for the field.
2047    Type *FDTy = FD->getType().getTypePtr();
2048
2049    // C99 6.7.2.1p2 - A field may not be a function type.
2050    if (FDTy->isFunctionType()) {
2051      Diag(FD->getLocation(), diag::err_field_declared_as_function,
2052           FD->getName());
2053      FD->setInvalidDecl();
2054      EnclosingDecl->setInvalidDecl();
2055      continue;
2056    }
2057    // C99 6.7.2.1p2 - A field may not be an incomplete type except...
2058    if (FDTy->isIncompleteType()) {
2059      if (!Record) {  // Incomplete ivar type is always an error.
2060        Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName());
2061        FD->setInvalidDecl();
2062        EnclosingDecl->setInvalidDecl();
2063        continue;
2064      }
2065      if (i != NumFields-1 ||                   // ... that the last member ...
2066          !Record->isStruct() ||  // ... of a structure ...
2067          !FDTy->isArrayType()) {         //... may have incomplete array type.
2068        Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName());
2069        FD->setInvalidDecl();
2070        EnclosingDecl->setInvalidDecl();
2071        continue;
2072      }
2073      if (NumNamedMembers < 1) {  //... must have more than named member ...
2074        Diag(FD->getLocation(), diag::err_flexible_array_empty_struct,
2075             FD->getName());
2076        FD->setInvalidDecl();
2077        EnclosingDecl->setInvalidDecl();
2078        continue;
2079      }
2080      // Okay, we have a legal flexible array member at the end of the struct.
2081      if (Record)
2082        Record->setHasFlexibleArrayMember(true);
2083    }
2084    /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the
2085    /// field of another structure or the element of an array.
2086    if (const RecordType *FDTTy = FDTy->getAsRecordType()) {
2087      if (FDTTy->getDecl()->hasFlexibleArrayMember()) {
2088        // If this is a member of a union, then entire union becomes "flexible".
2089        if (Record && Record->isUnion()) {
2090          Record->setHasFlexibleArrayMember(true);
2091        } else {
2092          // If this is a struct/class and this is not the last element, reject
2093          // it.  Note that GCC supports variable sized arrays in the middle of
2094          // structures.
2095          if (i != NumFields-1) {
2096            Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct,
2097                 FD->getName());
2098            FD->setInvalidDecl();
2099            EnclosingDecl->setInvalidDecl();
2100            continue;
2101          }
2102          // We support flexible arrays at the end of structs in other structs
2103          // as an extension.
2104          Diag(FD->getLocation(), diag::ext_flexible_array_in_struct,
2105               FD->getName());
2106          if (Record)
2107            Record->setHasFlexibleArrayMember(true);
2108        }
2109      }
2110    }
2111    /// A field cannot be an Objective-c object
2112    if (FDTy->isObjCInterfaceType()) {
2113      Diag(FD->getLocation(), diag::err_statically_allocated_object,
2114           FD->getName());
2115      FD->setInvalidDecl();
2116      EnclosingDecl->setInvalidDecl();
2117      continue;
2118    }
2119    // Keep track of the number of named members.
2120    if (IdentifierInfo *II = FD->getIdentifier()) {
2121      // Detect duplicate member names.
2122      if (!FieldIDs.insert(II)) {
2123        Diag(FD->getLocation(), diag::err_duplicate_member, II->getName());
2124        // Find the previous decl.
2125        SourceLocation PrevLoc;
2126        for (unsigned i = 0, e = RecFields.size(); ; ++i) {
2127          assert(i != e && "Didn't find previous def!");
2128          if (RecFields[i]->getIdentifier() == II) {
2129            PrevLoc = RecFields[i]->getLocation();
2130            break;
2131          }
2132        }
2133        Diag(PrevLoc, diag::err_previous_definition);
2134        FD->setInvalidDecl();
2135        EnclosingDecl->setInvalidDecl();
2136        continue;
2137      }
2138      ++NumNamedMembers;
2139    }
2140  }
2141
2142  // Okay, we successfully defined 'Record'.
2143  if (Record) {
2144    Record->defineBody(&RecFields[0], RecFields.size());
2145    // If this is a C++ record, HandleTagDeclDefinition will be invoked in
2146    // Sema::ActOnFinishCXXClassDef.
2147    if (!isa<CXXRecordDecl>(Record))
2148      Consumer.HandleTagDeclDefinition(Record);
2149  } else {
2150    ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]);
2151    if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl))
2152      ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac);
2153    else if (ObjCImplementationDecl *IMPDecl =
2154               dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) {
2155      assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl");
2156      IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size());
2157      CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac);
2158    }
2159  }
2160}
2161
2162Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl,
2163                                      DeclTy *lastEnumConst,
2164                                      SourceLocation IdLoc, IdentifierInfo *Id,
2165                                      SourceLocation EqualLoc, ExprTy *val) {
2166  EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl));
2167  EnumConstantDecl *LastEnumConst =
2168    cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst));
2169  Expr *Val = static_cast<Expr*>(val);
2170
2171  // The scope passed in may not be a decl scope.  Zip up the scope tree until
2172  // we find one that is.
2173  while ((S->getFlags() & Scope::DeclScope) == 0)
2174    S = S->getParent();
2175
2176  // Verify that there isn't already something declared with this name in this
2177  // scope.
2178  if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) {
2179    // When in C++, we may get a TagDecl with the same name; in this case the
2180    // enum constant will 'hide' the tag.
2181    assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) &&
2182           "Received TagDecl when not in C++!");
2183    if (!isa<TagDecl>(PrevDecl) &&
2184        IdResolver.isDeclInScope(PrevDecl, CurContext, S)) {
2185      if (isa<EnumConstantDecl>(PrevDecl))
2186        Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName());
2187      else
2188        Diag(IdLoc, diag::err_redefinition, Id->getName());
2189      Diag(PrevDecl->getLocation(), diag::err_previous_definition);
2190      delete Val;
2191      return 0;
2192    }
2193  }
2194
2195  llvm::APSInt EnumVal(32);
2196  QualType EltTy;
2197  if (Val) {
2198    // Make sure to promote the operand type to int.
2199    UsualUnaryConversions(Val);
2200
2201    // C99 6.7.2.2p2: Make sure we have an integer constant expression.
2202    SourceLocation ExpLoc;
2203    if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) {
2204      Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr,
2205           Id->getName());
2206      delete Val;
2207      Val = 0;  // Just forget about it.
2208    } else {
2209      EltTy = Val->getType();
2210    }
2211  }
2212
2213  if (!Val) {
2214    if (LastEnumConst) {
2215      // Assign the last value + 1.
2216      EnumVal = LastEnumConst->getInitVal();
2217      ++EnumVal;
2218
2219      // Check for overflow on increment.
2220      if (EnumVal < LastEnumConst->getInitVal())
2221        Diag(IdLoc, diag::warn_enum_value_overflow);
2222
2223      EltTy = LastEnumConst->getType();
2224    } else {
2225      // First value, set to zero.
2226      EltTy = Context.IntTy;
2227      EnumVal.zextOrTrunc(static_cast<uint32_t>(Context.getTypeSize(EltTy)));
2228    }
2229  }
2230
2231  EnumConstantDecl *New =
2232    EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy,
2233                             Val, EnumVal,
2234                             LastEnumConst);
2235
2236  // Register this decl in the current scope stack.
2237  PushOnScopeChains(New, S);
2238  return New;
2239}
2240
2241// FIXME: For consistency with ActOnFields(), we should have the parser
2242// pass in the source location for the left/right braces.
2243void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX,
2244                         DeclTy **Elements, unsigned NumElements) {
2245  EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX));
2246
2247  if (Enum && Enum->isDefinition()) {
2248    // Diagnose code like:
2249    //   enum e0 {
2250    //     E0 = sizeof(enum e0 { E1 })
2251    //   };
2252    Diag(Enum->getLocation(), diag::err_nested_redefinition,
2253         Enum->getName());
2254    Diag(EnumLoc, diag::err_previous_definition);
2255    Enum->setInvalidDecl();
2256    return;
2257  }
2258  // TODO: If the result value doesn't fit in an int, it must be a long or long
2259  // long value.  ISO C does not support this, but GCC does as an extension,
2260  // emit a warning.
2261  unsigned IntWidth = Context.Target.getIntWidth();
2262
2263  // Verify that all the values are okay, compute the size of the values, and
2264  // reverse the list.
2265  unsigned NumNegativeBits = 0;
2266  unsigned NumPositiveBits = 0;
2267
2268  // Keep track of whether all elements have type int.
2269  bool AllElementsInt = true;
2270
2271  EnumConstantDecl *EltList = 0;
2272  for (unsigned i = 0; i != NumElements; ++i) {
2273    EnumConstantDecl *ECD =
2274      cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i]));
2275    if (!ECD) continue;  // Already issued a diagnostic.
2276
2277    // If the enum value doesn't fit in an int, emit an extension warning.
2278    const llvm::APSInt &InitVal = ECD->getInitVal();
2279    assert(InitVal.getBitWidth() >= IntWidth &&
2280           "Should have promoted value to int");
2281    if (InitVal.getBitWidth() > IntWidth) {
2282      llvm::APSInt V(InitVal);
2283      V.trunc(IntWidth);
2284      V.extend(InitVal.getBitWidth());
2285      if (V != InitVal)
2286        Diag(ECD->getLocation(), diag::ext_enum_value_not_int,
2287             InitVal.toString());
2288    }
2289
2290    // Keep track of the size of positive and negative values.
2291    if (InitVal.isUnsigned() || InitVal.isNonNegative())
2292      NumPositiveBits = std::max(NumPositiveBits,
2293                                 (unsigned)InitVal.getActiveBits());
2294    else
2295      NumNegativeBits = std::max(NumNegativeBits,
2296                                 (unsigned)InitVal.getMinSignedBits());
2297
2298    // Keep track of whether every enum element has type int (very commmon).
2299    if (AllElementsInt)
2300      AllElementsInt = ECD->getType() == Context.IntTy;
2301
2302    ECD->setNextDeclarator(EltList);
2303    EltList = ECD;
2304  }
2305
2306  // Figure out the type that should be used for this enum.
2307  // FIXME: Support attribute(packed) on enums and -fshort-enums.
2308  QualType BestType;
2309  unsigned BestWidth;
2310
2311  if (NumNegativeBits) {
2312    // If there is a negative value, figure out the smallest integer type (of
2313    // int/long/longlong) that fits.
2314    if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) {
2315      BestType = Context.IntTy;
2316      BestWidth = IntWidth;
2317    } else {
2318      BestWidth = Context.Target.getLongWidth();
2319
2320      if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth)
2321        BestType = Context.LongTy;
2322      else {
2323        BestWidth = Context.Target.getLongLongWidth();
2324
2325        if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth)
2326          Diag(Enum->getLocation(), diag::warn_enum_too_large);
2327        BestType = Context.LongLongTy;
2328      }
2329    }
2330  } else {
2331    // If there is no negative value, figure out which of uint, ulong, ulonglong
2332    // fits.
2333    if (NumPositiveBits <= IntWidth) {
2334      BestType = Context.UnsignedIntTy;
2335      BestWidth = IntWidth;
2336    } else if (NumPositiveBits <=
2337               (BestWidth = Context.Target.getLongWidth())) {
2338      BestType = Context.UnsignedLongTy;
2339    } else {
2340      BestWidth = Context.Target.getLongLongWidth();
2341      assert(NumPositiveBits <= BestWidth &&
2342             "How could an initializer get larger than ULL?");
2343      BestType = Context.UnsignedLongLongTy;
2344    }
2345  }
2346
2347  // Loop over all of the enumerator constants, changing their types to match
2348  // the type of the enum if needed.
2349  for (unsigned i = 0; i != NumElements; ++i) {
2350    EnumConstantDecl *ECD =
2351      cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i]));
2352    if (!ECD) continue;  // Already issued a diagnostic.
2353
2354    // Standard C says the enumerators have int type, but we allow, as an
2355    // extension, the enumerators to be larger than int size.  If each
2356    // enumerator value fits in an int, type it as an int, otherwise type it the
2357    // same as the enumerator decl itself.  This means that in "enum { X = 1U }"
2358    // that X has type 'int', not 'unsigned'.
2359    if (ECD->getType() == Context.IntTy) {
2360      // Make sure the init value is signed.
2361      llvm::APSInt IV = ECD->getInitVal();
2362      IV.setIsSigned(true);
2363      ECD->setInitVal(IV);
2364      continue;  // Already int type.
2365    }
2366
2367    // Determine whether the value fits into an int.
2368    llvm::APSInt InitVal = ECD->getInitVal();
2369    bool FitsInInt;
2370    if (InitVal.isUnsigned() || !InitVal.isNegative())
2371      FitsInInt = InitVal.getActiveBits() < IntWidth;
2372    else
2373      FitsInInt = InitVal.getMinSignedBits() <= IntWidth;
2374
2375    // If it fits into an integer type, force it.  Otherwise force it to match
2376    // the enum decl type.
2377    QualType NewTy;
2378    unsigned NewWidth;
2379    bool NewSign;
2380    if (FitsInInt) {
2381      NewTy = Context.IntTy;
2382      NewWidth = IntWidth;
2383      NewSign = true;
2384    } else if (ECD->getType() == BestType) {
2385      // Already the right type!
2386      continue;
2387    } else {
2388      NewTy = BestType;
2389      NewWidth = BestWidth;
2390      NewSign = BestType->isSignedIntegerType();
2391    }
2392
2393    // Adjust the APSInt value.
2394    InitVal.extOrTrunc(NewWidth);
2395    InitVal.setIsSigned(NewSign);
2396    ECD->setInitVal(InitVal);
2397
2398    // Adjust the Expr initializer and type.
2399    ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr()));
2400    ECD->setType(NewTy);
2401  }
2402
2403  Enum->defineElements(EltList, BestType);
2404  Consumer.HandleTagDeclDefinition(Enum);
2405}
2406
2407Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc,
2408                                          ExprTy *expr) {
2409  StringLiteral *AsmString = cast<StringLiteral>((Expr*)expr);
2410
2411  return FileScopeAsmDecl::Create(Context, Loc, AsmString);
2412}
2413
2414Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc,
2415                                     SourceLocation LBrace,
2416                                     SourceLocation RBrace,
2417                                     const char *Lang,
2418                                     unsigned StrSize,
2419                                     DeclTy *D) {
2420  LinkageSpecDecl::LanguageIDs Language;
2421  Decl *dcl = static_cast<Decl *>(D);
2422  if (strncmp(Lang, "\"C\"", StrSize) == 0)
2423    Language = LinkageSpecDecl::lang_c;
2424  else if (strncmp(Lang, "\"C++\"", StrSize) == 0)
2425    Language = LinkageSpecDecl::lang_cxx;
2426  else {
2427    Diag(Loc, diag::err_bad_language);
2428    return 0;
2429  }
2430
2431  // FIXME: Add all the various semantics of linkage specifications
2432  return LinkageSpecDecl::Create(Context, Loc, Language, dcl);
2433}
2434