1 //===--- SemaDeclSpec.cpp - Declaration Specifier Semantic Analysis -------===//
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 declaration specifiers.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Parse/ParseDiagnostic.h" // FIXME: remove this back-dependency!
15 #include "clang/Sema/DeclSpec.h"
16 #include "clang/Sema/ParsedTemplate.h"
17 #include "clang/AST/ASTContext.h"
18 #include "clang/AST/NestedNameSpecifier.h"
19 #include "clang/AST/TypeLoc.h"
20 #include "clang/Lex/Preprocessor.h"
21 #include "clang/Basic/LangOptions.h"
22 #include "llvm/ADT/STLExtras.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include <cstring>
25 using namespace clang;
26 
27 
28 static DiagnosticBuilder Diag(Diagnostic &D, SourceLocation Loc,
29                               unsigned DiagID) {
30   return D.Report(Loc, DiagID);
31 }
32 
33 
34 void UnqualifiedId::setTemplateId(TemplateIdAnnotation *TemplateId) {
35   assert(TemplateId && "NULL template-id annotation?");
36   Kind = IK_TemplateId;
37   this->TemplateId = TemplateId;
38   StartLocation = TemplateId->TemplateNameLoc;
39   EndLocation = TemplateId->RAngleLoc;
40 }
41 
42 void UnqualifiedId::setConstructorTemplateId(TemplateIdAnnotation *TemplateId) {
43   assert(TemplateId && "NULL template-id annotation?");
44   Kind = IK_ConstructorTemplateId;
45   this->TemplateId = TemplateId;
46   StartLocation = TemplateId->TemplateNameLoc;
47   EndLocation = TemplateId->RAngleLoc;
48 }
49 
50 void CXXScopeSpec::Extend(ASTContext &Context, SourceLocation TemplateKWLoc,
51                           TypeLoc TL, SourceLocation ColonColonLoc) {
52   Builder.Extend(Context, TemplateKWLoc, TL, ColonColonLoc);
53   if (Range.getBegin().isInvalid())
54     Range.setBegin(TL.getBeginLoc());
55   Range.setEnd(ColonColonLoc);
56 
57   assert(Range == Builder.getSourceRange() &&
58          "NestedNameSpecifierLoc range computation incorrect");
59 }
60 
61 void CXXScopeSpec::Extend(ASTContext &Context, IdentifierInfo *Identifier,
62                           SourceLocation IdentifierLoc,
63                           SourceLocation ColonColonLoc) {
64   Builder.Extend(Context, Identifier, IdentifierLoc, ColonColonLoc);
65 
66   if (Range.getBegin().isInvalid())
67     Range.setBegin(IdentifierLoc);
68   Range.setEnd(ColonColonLoc);
69 
70   assert(Range == Builder.getSourceRange() &&
71          "NestedNameSpecifierLoc range computation incorrect");
72 }
73 
74 void CXXScopeSpec::Extend(ASTContext &Context, NamespaceDecl *Namespace,
75                           SourceLocation NamespaceLoc,
76                           SourceLocation ColonColonLoc) {
77   Builder.Extend(Context, Namespace, NamespaceLoc, ColonColonLoc);
78 
79   if (Range.getBegin().isInvalid())
80     Range.setBegin(NamespaceLoc);
81   Range.setEnd(ColonColonLoc);
82 
83   assert(Range == Builder.getSourceRange() &&
84          "NestedNameSpecifierLoc range computation incorrect");
85 }
86 
87 void CXXScopeSpec::Extend(ASTContext &Context, NamespaceAliasDecl *Alias,
88                           SourceLocation AliasLoc,
89                           SourceLocation ColonColonLoc) {
90   Builder.Extend(Context, Alias, AliasLoc, ColonColonLoc);
91 
92   if (Range.getBegin().isInvalid())
93     Range.setBegin(AliasLoc);
94   Range.setEnd(ColonColonLoc);
95 
96   assert(Range == Builder.getSourceRange() &&
97          "NestedNameSpecifierLoc range computation incorrect");
98 }
99 
100 void CXXScopeSpec::MakeGlobal(ASTContext &Context,
101                               SourceLocation ColonColonLoc) {
102   Builder.MakeGlobal(Context, ColonColonLoc);
103 
104   Range = SourceRange(ColonColonLoc);
105 
106   assert(Range == Builder.getSourceRange() &&
107          "NestedNameSpecifierLoc range computation incorrect");
108 }
109 
110 void CXXScopeSpec::MakeTrivial(ASTContext &Context,
111                                NestedNameSpecifier *Qualifier, SourceRange R) {
112   Builder.MakeTrivial(Context, Qualifier, R);
113   Range = R;
114 }
115 
116 void CXXScopeSpec::Adopt(NestedNameSpecifierLoc Other) {
117   if (!Other) {
118     Range = SourceRange();
119     Builder.Clear();
120     return;
121   }
122 
123   Range = Other.getSourceRange();
124   Builder.Adopt(Other);
125 }
126 
127 NestedNameSpecifierLoc
128 CXXScopeSpec::getWithLocInContext(ASTContext &Context) const {
129   if (!Builder.getRepresentation())
130     return NestedNameSpecifierLoc();
131 
132   return Builder.getWithLocInContext(Context);
133 }
134 
135 /// DeclaratorChunk::getFunction - Return a DeclaratorChunk for a function.
136 /// "TheDeclarator" is the declarator that this will be added to.
137 DeclaratorChunk DeclaratorChunk::getFunction(bool hasProto, bool isVariadic,
138                                              SourceLocation EllipsisLoc,
139                                              ParamInfo *ArgInfo,
140                                              unsigned NumArgs,
141                                              unsigned TypeQuals,
142                                              bool RefQualifierIsLvalueRef,
143                                              SourceLocation RefQualifierLoc,
144                                              ExceptionSpecificationType
145                                                  ESpecType,
146                                              SourceLocation ESpecLoc,
147                                              ParsedType *Exceptions,
148                                              SourceRange *ExceptionRanges,
149                                              unsigned NumExceptions,
150                                              Expr *NoexceptExpr,
151                                              SourceLocation LocalRangeBegin,
152                                              SourceLocation LocalRangeEnd,
153                                              Declarator &TheDeclarator,
154                                              ParsedType TrailingReturnType) {
155   DeclaratorChunk I;
156   I.Kind                        = Function;
157   I.Loc                         = LocalRangeBegin;
158   I.EndLoc                      = LocalRangeEnd;
159   I.Fun.AttrList                = 0;
160   I.Fun.hasPrototype            = hasProto;
161   I.Fun.isVariadic              = isVariadic;
162   I.Fun.EllipsisLoc             = EllipsisLoc.getRawEncoding();
163   I.Fun.DeleteArgInfo           = false;
164   I.Fun.TypeQuals               = TypeQuals;
165   I.Fun.NumArgs                 = NumArgs;
166   I.Fun.ArgInfo                 = 0;
167   I.Fun.RefQualifierIsLValueRef = RefQualifierIsLvalueRef;
168   I.Fun.RefQualifierLoc         = RefQualifierLoc.getRawEncoding();
169   I.Fun.ExceptionSpecType       = ESpecType;
170   I.Fun.ExceptionSpecLoc        = ESpecLoc.getRawEncoding();
171   I.Fun.NumExceptions           = 0;
172   I.Fun.Exceptions              = 0;
173   I.Fun.NoexceptExpr            = 0;
174   I.Fun.TrailingReturnType   = TrailingReturnType.getAsOpaquePtr();
175 
176   // new[] an argument array if needed.
177   if (NumArgs) {
178     // If the 'InlineParams' in Declarator is unused and big enough, put our
179     // parameter list there (in an effort to avoid new/delete traffic).  If it
180     // is already used (consider a function returning a function pointer) or too
181     // small (function taking too many arguments), go to the heap.
182     if (!TheDeclarator.InlineParamsUsed &&
183         NumArgs <= llvm::array_lengthof(TheDeclarator.InlineParams)) {
184       I.Fun.ArgInfo = TheDeclarator.InlineParams;
185       I.Fun.DeleteArgInfo = false;
186       TheDeclarator.InlineParamsUsed = true;
187     } else {
188       I.Fun.ArgInfo = new DeclaratorChunk::ParamInfo[NumArgs];
189       I.Fun.DeleteArgInfo = true;
190     }
191     memcpy(I.Fun.ArgInfo, ArgInfo, sizeof(ArgInfo[0])*NumArgs);
192   }
193 
194   // Check what exception specification information we should actually store.
195   switch (ESpecType) {
196   default: break; // By default, save nothing.
197   case EST_Dynamic:
198     // new[] an exception array if needed
199     if (NumExceptions) {
200       I.Fun.NumExceptions = NumExceptions;
201       I.Fun.Exceptions = new DeclaratorChunk::TypeAndRange[NumExceptions];
202       for (unsigned i = 0; i != NumExceptions; ++i) {
203         I.Fun.Exceptions[i].Ty = Exceptions[i];
204         I.Fun.Exceptions[i].Range = ExceptionRanges[i];
205       }
206     }
207     break;
208 
209   case EST_ComputedNoexcept:
210     I.Fun.NoexceptExpr = NoexceptExpr;
211     break;
212   }
213   return I;
214 }
215 
216 /// getParsedSpecifiers - Return a bitmask of which flavors of specifiers this
217 /// declaration specifier includes.
218 ///
219 unsigned DeclSpec::getParsedSpecifiers() const {
220   unsigned Res = 0;
221   if (StorageClassSpec != SCS_unspecified ||
222       SCS_thread_specified)
223     Res |= PQ_StorageClassSpecifier;
224 
225   if (TypeQualifiers != TQ_unspecified)
226     Res |= PQ_TypeQualifier;
227 
228   if (hasTypeSpecifier())
229     Res |= PQ_TypeSpecifier;
230 
231   if (FS_inline_specified || FS_virtual_specified || FS_explicit_specified)
232     Res |= PQ_FunctionSpecifier;
233   return Res;
234 }
235 
236 template <class T> static bool BadSpecifier(T TNew, T TPrev,
237                                             const char *&PrevSpec,
238                                             unsigned &DiagID) {
239   PrevSpec = DeclSpec::getSpecifierName(TPrev);
240   DiagID = (TNew == TPrev ? diag::ext_duplicate_declspec
241             : diag::err_invalid_decl_spec_combination);
242   return true;
243 }
244 
245 const char *DeclSpec::getSpecifierName(DeclSpec::SCS S) {
246   switch (S) {
247   case DeclSpec::SCS_unspecified: return "unspecified";
248   case DeclSpec::SCS_typedef:     return "typedef";
249   case DeclSpec::SCS_extern:      return "extern";
250   case DeclSpec::SCS_static:      return "static";
251   case DeclSpec::SCS_auto:        return "auto";
252   case DeclSpec::SCS_register:    return "register";
253   case DeclSpec::SCS_private_extern: return "__private_extern__";
254   case DeclSpec::SCS_mutable:     return "mutable";
255   }
256   llvm_unreachable("Unknown typespec!");
257 }
258 
259 const char *DeclSpec::getSpecifierName(TSW W) {
260   switch (W) {
261   case TSW_unspecified: return "unspecified";
262   case TSW_short:       return "short";
263   case TSW_long:        return "long";
264   case TSW_longlong:    return "long long";
265   }
266   llvm_unreachable("Unknown typespec!");
267 }
268 
269 const char *DeclSpec::getSpecifierName(TSC C) {
270   switch (C) {
271   case TSC_unspecified: return "unspecified";
272   case TSC_imaginary:   return "imaginary";
273   case TSC_complex:     return "complex";
274   }
275   llvm_unreachable("Unknown typespec!");
276 }
277 
278 
279 const char *DeclSpec::getSpecifierName(TSS S) {
280   switch (S) {
281   case TSS_unspecified: return "unspecified";
282   case TSS_signed:      return "signed";
283   case TSS_unsigned:    return "unsigned";
284   }
285   llvm_unreachable("Unknown typespec!");
286 }
287 
288 const char *DeclSpec::getSpecifierName(DeclSpec::TST T) {
289   switch (T) {
290   case DeclSpec::TST_unspecified: return "unspecified";
291   case DeclSpec::TST_void:        return "void";
292   case DeclSpec::TST_char:        return "char";
293   case DeclSpec::TST_wchar:       return "wchar_t";
294   case DeclSpec::TST_char16:      return "char16_t";
295   case DeclSpec::TST_char32:      return "char32_t";
296   case DeclSpec::TST_int:         return "int";
297   case DeclSpec::TST_float:       return "float";
298   case DeclSpec::TST_double:      return "double";
299   case DeclSpec::TST_bool:        return "_Bool";
300   case DeclSpec::TST_decimal32:   return "_Decimal32";
301   case DeclSpec::TST_decimal64:   return "_Decimal64";
302   case DeclSpec::TST_decimal128:  return "_Decimal128";
303   case DeclSpec::TST_enum:        return "enum";
304   case DeclSpec::TST_class:       return "class";
305   case DeclSpec::TST_union:       return "union";
306   case DeclSpec::TST_struct:      return "struct";
307   case DeclSpec::TST_typename:    return "type-name";
308   case DeclSpec::TST_typeofType:
309   case DeclSpec::TST_typeofExpr:  return "typeof";
310   case DeclSpec::TST_auto:        return "auto";
311   case DeclSpec::TST_decltype:    return "(decltype)";
312   case DeclSpec::TST_unknown_anytype: return "__unknown_anytype";
313   case DeclSpec::TST_error:       return "(error)";
314   }
315   llvm_unreachable("Unknown typespec!");
316 }
317 
318 const char *DeclSpec::getSpecifierName(TQ T) {
319   switch (T) {
320   case DeclSpec::TQ_unspecified: return "unspecified";
321   case DeclSpec::TQ_const:       return "const";
322   case DeclSpec::TQ_restrict:    return "restrict";
323   case DeclSpec::TQ_volatile:    return "volatile";
324   }
325   llvm_unreachable("Unknown typespec!");
326 }
327 
328 bool DeclSpec::SetStorageClassSpec(SCS S, SourceLocation Loc,
329                                    const char *&PrevSpec,
330                                    unsigned &DiagID,
331                                    const LangOptions &Lang) {
332   // OpenCL prohibits extern, auto, register, and static
333   // It seems sensible to prohibit private_extern too
334   if (Lang.OpenCL) {
335     switch (S) {
336     case SCS_extern:
337     case SCS_private_extern:
338     case SCS_auto:
339     case SCS_register:
340     case SCS_static:
341       DiagID   = diag::err_not_opencl_storage_class_specifier;
342       PrevSpec = getSpecifierName(S);
343       return true;
344     default:
345       break;
346     }
347   }
348 
349   if (StorageClassSpec != SCS_unspecified) {
350     // Changing storage class is allowed only if the previous one
351     // was the 'extern' that is part of a linkage specification and
352     // the new storage class is 'typedef'.
353     if (!(SCS_extern_in_linkage_spec &&
354           StorageClassSpec == SCS_extern &&
355           S == SCS_typedef))
356       return BadSpecifier(S, (SCS)StorageClassSpec, PrevSpec, DiagID);
357   }
358   StorageClassSpec = S;
359   StorageClassSpecLoc = Loc;
360   assert((unsigned)S == StorageClassSpec && "SCS constants overflow bitfield");
361   return false;
362 }
363 
364 bool DeclSpec::SetStorageClassSpecThread(SourceLocation Loc,
365                                          const char *&PrevSpec,
366                                          unsigned &DiagID) {
367   if (SCS_thread_specified) {
368     PrevSpec = "__thread";
369     DiagID = diag::ext_duplicate_declspec;
370     return true;
371   }
372   SCS_thread_specified = true;
373   SCS_threadLoc = Loc;
374   return false;
375 }
376 
377 /// These methods set the specified attribute of the DeclSpec, but return true
378 /// and ignore the request if invalid (e.g. "extern" then "auto" is
379 /// specified).
380 bool DeclSpec::SetTypeSpecWidth(TSW W, SourceLocation Loc,
381                                 const char *&PrevSpec,
382                                 unsigned &DiagID) {
383   // Overwrite TSWLoc only if TypeSpecWidth was unspecified, so that
384   // for 'long long' we will keep the source location of the first 'long'.
385   if (TypeSpecWidth == TSW_unspecified)
386     TSWLoc = Loc;
387   // Allow turning long -> long long.
388   else if (W != TSW_longlong || TypeSpecWidth != TSW_long)
389     return BadSpecifier(W, (TSW)TypeSpecWidth, PrevSpec, DiagID);
390   TypeSpecWidth = W;
391   if (TypeAltiVecVector && !TypeAltiVecBool &&
392       ((TypeSpecWidth == TSW_long) || (TypeSpecWidth == TSW_longlong))) {
393     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType);
394     DiagID = diag::warn_vector_long_decl_spec_combination;
395     return true;
396   }
397   return false;
398 }
399 
400 bool DeclSpec::SetTypeSpecComplex(TSC C, SourceLocation Loc,
401                                   const char *&PrevSpec,
402                                   unsigned &DiagID) {
403   if (TypeSpecComplex != TSC_unspecified)
404     return BadSpecifier(C, (TSC)TypeSpecComplex, PrevSpec, DiagID);
405   TypeSpecComplex = C;
406   TSCLoc = Loc;
407   return false;
408 }
409 
410 bool DeclSpec::SetTypeSpecSign(TSS S, SourceLocation Loc,
411                                const char *&PrevSpec,
412                                unsigned &DiagID) {
413   if (TypeSpecSign != TSS_unspecified)
414     return BadSpecifier(S, (TSS)TypeSpecSign, PrevSpec, DiagID);
415   TypeSpecSign = S;
416   TSSLoc = Loc;
417   return false;
418 }
419 
420 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
421                                const char *&PrevSpec,
422                                unsigned &DiagID,
423                                ParsedType Rep) {
424   return SetTypeSpecType(T, Loc, Loc, PrevSpec, DiagID, Rep);
425 }
426 
427 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation TagKwLoc,
428                                SourceLocation TagNameLoc,
429                                const char *&PrevSpec,
430                                unsigned &DiagID,
431                                ParsedType Rep) {
432   assert(isTypeRep(T) && "T does not store a type");
433   assert(Rep && "no type provided!");
434   if (TypeSpecType != TST_unspecified) {
435     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType);
436     DiagID = diag::err_invalid_decl_spec_combination;
437     return true;
438   }
439   TypeSpecType = T;
440   TypeRep = Rep;
441   TSTLoc = TagKwLoc;
442   TSTNameLoc = TagNameLoc;
443   TypeSpecOwned = false;
444   return false;
445 }
446 
447 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
448                                const char *&PrevSpec,
449                                unsigned &DiagID,
450                                Expr *Rep) {
451   assert(isExprRep(T) && "T does not store an expr");
452   assert(Rep && "no expression provided!");
453   if (TypeSpecType != TST_unspecified) {
454     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType);
455     DiagID = diag::err_invalid_decl_spec_combination;
456     return true;
457   }
458   TypeSpecType = T;
459   ExprRep = Rep;
460   TSTLoc = Loc;
461   TSTNameLoc = Loc;
462   TypeSpecOwned = false;
463   return false;
464 }
465 
466 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
467                                const char *&PrevSpec,
468                                unsigned &DiagID,
469                                Decl *Rep, bool Owned) {
470   return SetTypeSpecType(T, Loc, Loc, PrevSpec, DiagID, Rep, Owned);
471 }
472 
473 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation TagKwLoc,
474                                SourceLocation TagNameLoc,
475                                const char *&PrevSpec,
476                                unsigned &DiagID,
477                                Decl *Rep, bool Owned) {
478   assert(isDeclRep(T) && "T does not store a decl");
479   // Unlike the other cases, we don't assert that we actually get a decl.
480 
481   if (TypeSpecType != TST_unspecified) {
482     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType);
483     DiagID = diag::err_invalid_decl_spec_combination;
484     return true;
485   }
486   TypeSpecType = T;
487   DeclRep = Rep;
488   TSTLoc = TagKwLoc;
489   TSTNameLoc = TagNameLoc;
490   TypeSpecOwned = Owned;
491   return false;
492 }
493 
494 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
495                                const char *&PrevSpec,
496                                unsigned &DiagID) {
497   assert(!isDeclRep(T) && !isTypeRep(T) && !isExprRep(T) &&
498          "rep required for these type-spec kinds!");
499   if (TypeSpecType != TST_unspecified) {
500     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType);
501     DiagID = diag::err_invalid_decl_spec_combination;
502     return true;
503   }
504   TSTLoc = Loc;
505   TSTNameLoc = Loc;
506   if (TypeAltiVecVector && (T == TST_bool) && !TypeAltiVecBool) {
507     TypeAltiVecBool = true;
508     return false;
509   }
510   TypeSpecType = T;
511   TypeSpecOwned = false;
512   if (TypeAltiVecVector && !TypeAltiVecBool && (TypeSpecType == TST_double)) {
513     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType);
514     DiagID = diag::err_invalid_vector_decl_spec;
515     return true;
516   }
517   return false;
518 }
519 
520 bool DeclSpec::SetTypeAltiVecVector(bool isAltiVecVector, SourceLocation Loc,
521                           const char *&PrevSpec, unsigned &DiagID) {
522   if (TypeSpecType != TST_unspecified) {
523     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType);
524     DiagID = diag::err_invalid_vector_decl_spec_combination;
525     return true;
526   }
527   TypeAltiVecVector = isAltiVecVector;
528   AltiVecLoc = Loc;
529   return false;
530 }
531 
532 bool DeclSpec::SetTypeAltiVecPixel(bool isAltiVecPixel, SourceLocation Loc,
533                           const char *&PrevSpec, unsigned &DiagID) {
534   if (!TypeAltiVecVector || TypeAltiVecPixel ||
535       (TypeSpecType != TST_unspecified)) {
536     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType);
537     DiagID = diag::err_invalid_pixel_decl_spec_combination;
538     return true;
539   }
540   TypeAltiVecPixel = isAltiVecPixel;
541   TSTLoc = Loc;
542   TSTNameLoc = Loc;
543   return false;
544 }
545 
546 bool DeclSpec::SetTypeSpecError() {
547   TypeSpecType = TST_error;
548   TypeSpecOwned = false;
549   TSTLoc = SourceLocation();
550   TSTNameLoc = SourceLocation();
551   return false;
552 }
553 
554 bool DeclSpec::SetTypeQual(TQ T, SourceLocation Loc, const char *&PrevSpec,
555                            unsigned &DiagID, const LangOptions &Lang) {
556   // Duplicates turn into warnings pre-C99.
557   if ((TypeQualifiers & T) && !Lang.C99)
558     return BadSpecifier(T, T, PrevSpec, DiagID);
559   TypeQualifiers |= T;
560 
561   switch (T) {
562   default: assert(0 && "Unknown type qualifier!");
563   case TQ_const:    TQ_constLoc = Loc; break;
564   case TQ_restrict: TQ_restrictLoc = Loc; break;
565   case TQ_volatile: TQ_volatileLoc = Loc; break;
566   }
567   return false;
568 }
569 
570 bool DeclSpec::SetFunctionSpecInline(SourceLocation Loc, const char *&PrevSpec,
571                                      unsigned &DiagID) {
572   // 'inline inline' is ok.
573   FS_inline_specified = true;
574   FS_inlineLoc = Loc;
575   return false;
576 }
577 
578 bool DeclSpec::SetFunctionSpecVirtual(SourceLocation Loc, const char *&PrevSpec,
579                                       unsigned &DiagID) {
580   // 'virtual virtual' is ok.
581   FS_virtual_specified = true;
582   FS_virtualLoc = Loc;
583   return false;
584 }
585 
586 bool DeclSpec::SetFunctionSpecExplicit(SourceLocation Loc, const char *&PrevSpec,
587                                        unsigned &DiagID) {
588   // 'explicit explicit' is ok.
589   FS_explicit_specified = true;
590   FS_explicitLoc = Loc;
591   return false;
592 }
593 
594 bool DeclSpec::SetFriendSpec(SourceLocation Loc, const char *&PrevSpec,
595                              unsigned &DiagID) {
596   if (Friend_specified) {
597     PrevSpec = "friend";
598     DiagID = diag::ext_duplicate_declspec;
599     return true;
600   }
601 
602   Friend_specified = true;
603   FriendLoc = Loc;
604   return false;
605 }
606 
607 bool DeclSpec::SetConstexprSpec(SourceLocation Loc, const char *&PrevSpec,
608                                 unsigned &DiagID) {
609   // 'constexpr constexpr' is ok.
610   Constexpr_specified = true;
611   ConstexprLoc = Loc;
612   return false;
613 }
614 
615 void DeclSpec::setProtocolQualifiers(Decl * const *Protos,
616                                      unsigned NP,
617                                      SourceLocation *ProtoLocs,
618                                      SourceLocation LAngleLoc) {
619   if (NP == 0) return;
620   ProtocolQualifiers = new Decl*[NP];
621   ProtocolLocs = new SourceLocation[NP];
622   memcpy((void*)ProtocolQualifiers, Protos, sizeof(Decl*)*NP);
623   memcpy(ProtocolLocs, ProtoLocs, sizeof(SourceLocation)*NP);
624   NumProtocolQualifiers = NP;
625   ProtocolLAngleLoc = LAngleLoc;
626 }
627 
628 void DeclSpec::SaveWrittenBuiltinSpecs() {
629   writtenBS.Sign = getTypeSpecSign();
630   writtenBS.Width = getTypeSpecWidth();
631   writtenBS.Type = getTypeSpecType();
632   // Search the list of attributes for the presence of a mode attribute.
633   writtenBS.ModeAttr = false;
634   AttributeList* attrs = getAttributes().getList();
635   while (attrs) {
636     if (attrs->getKind() == AttributeList::AT_mode) {
637       writtenBS.ModeAttr = true;
638       break;
639     }
640     attrs = attrs->getNext();
641   }
642 }
643 
644 void DeclSpec::SaveStorageSpecifierAsWritten() {
645   if (SCS_extern_in_linkage_spec && StorageClassSpec == SCS_extern)
646     // If 'extern' is part of a linkage specification,
647     // then it is not a storage class "as written".
648     StorageClassSpecAsWritten = SCS_unspecified;
649   else
650     StorageClassSpecAsWritten = StorageClassSpec;
651 }
652 
653 /// Finish - This does final analysis of the declspec, rejecting things like
654 /// "_Imaginary" (lacking an FP type).  This returns a diagnostic to issue or
655 /// diag::NUM_DIAGNOSTICS if there is no error.  After calling this method,
656 /// DeclSpec is guaranteed self-consistent, even if an error occurred.
657 void DeclSpec::Finish(Diagnostic &D, Preprocessor &PP) {
658   // Before possibly changing their values, save specs as written.
659   SaveWrittenBuiltinSpecs();
660   SaveStorageSpecifierAsWritten();
661 
662   // Check the type specifier components first.
663 
664   // Validate and finalize AltiVec vector declspec.
665   if (TypeAltiVecVector) {
666     if (TypeAltiVecBool) {
667       // Sign specifiers are not allowed with vector bool. (PIM 2.1)
668       if (TypeSpecSign != TSS_unspecified) {
669         Diag(D, TSSLoc, diag::err_invalid_vector_bool_decl_spec)
670           << getSpecifierName((TSS)TypeSpecSign);
671       }
672 
673       // Only char/int are valid with vector bool. (PIM 2.1)
674       if (((TypeSpecType != TST_unspecified) && (TypeSpecType != TST_char) &&
675            (TypeSpecType != TST_int)) || TypeAltiVecPixel) {
676         Diag(D, TSTLoc, diag::err_invalid_vector_bool_decl_spec)
677           << (TypeAltiVecPixel ? "__pixel" :
678                                  getSpecifierName((TST)TypeSpecType));
679       }
680 
681       // Only 'short' is valid with vector bool. (PIM 2.1)
682       if ((TypeSpecWidth != TSW_unspecified) && (TypeSpecWidth != TSW_short))
683         Diag(D, TSWLoc, diag::err_invalid_vector_bool_decl_spec)
684           << getSpecifierName((TSW)TypeSpecWidth);
685 
686       // Elements of vector bool are interpreted as unsigned. (PIM 2.1)
687       if ((TypeSpecType == TST_char) || (TypeSpecType == TST_int) ||
688           (TypeSpecWidth != TSW_unspecified))
689         TypeSpecSign = TSS_unsigned;
690     }
691 
692     if (TypeAltiVecPixel) {
693       //TODO: perform validation
694       TypeSpecType = TST_int;
695       TypeSpecSign = TSS_unsigned;
696       TypeSpecWidth = TSW_short;
697       TypeSpecOwned = false;
698     }
699   }
700 
701   // signed/unsigned are only valid with int/char/wchar_t.
702   if (TypeSpecSign != TSS_unspecified) {
703     if (TypeSpecType == TST_unspecified)
704       TypeSpecType = TST_int; // unsigned -> unsigned int, signed -> signed int.
705     else if (TypeSpecType != TST_int  &&
706              TypeSpecType != TST_char && TypeSpecType != TST_wchar) {
707       Diag(D, TSSLoc, diag::err_invalid_sign_spec)
708         << getSpecifierName((TST)TypeSpecType);
709       // signed double -> double.
710       TypeSpecSign = TSS_unspecified;
711     }
712   }
713 
714   // Validate the width of the type.
715   switch (TypeSpecWidth) {
716   case TSW_unspecified: break;
717   case TSW_short:    // short int
718   case TSW_longlong: // long long int
719     if (TypeSpecType == TST_unspecified)
720       TypeSpecType = TST_int; // short -> short int, long long -> long long int.
721     else if (TypeSpecType != TST_int) {
722       Diag(D, TSWLoc,
723            TypeSpecWidth == TSW_short ? diag::err_invalid_short_spec
724                                       : diag::err_invalid_longlong_spec)
725         <<  getSpecifierName((TST)TypeSpecType);
726       TypeSpecType = TST_int;
727       TypeSpecOwned = false;
728     }
729     break;
730   case TSW_long:  // long double, long int
731     if (TypeSpecType == TST_unspecified)
732       TypeSpecType = TST_int;  // long -> long int.
733     else if (TypeSpecType != TST_int && TypeSpecType != TST_double) {
734       Diag(D, TSWLoc, diag::err_invalid_long_spec)
735         << getSpecifierName((TST)TypeSpecType);
736       TypeSpecType = TST_int;
737       TypeSpecOwned = false;
738     }
739     break;
740   }
741 
742   // TODO: if the implementation does not implement _Complex or _Imaginary,
743   // disallow their use.  Need information about the backend.
744   if (TypeSpecComplex != TSC_unspecified) {
745     if (TypeSpecType == TST_unspecified) {
746       Diag(D, TSCLoc, diag::ext_plain_complex)
747         << FixItHint::CreateInsertion(
748                               PP.getLocForEndOfToken(getTypeSpecComplexLoc()),
749                                                  " double");
750       TypeSpecType = TST_double;   // _Complex -> _Complex double.
751     } else if (TypeSpecType == TST_int || TypeSpecType == TST_char) {
752       // Note that this intentionally doesn't include _Complex _Bool.
753       Diag(D, TSTLoc, diag::ext_integer_complex);
754     } else if (TypeSpecType != TST_float && TypeSpecType != TST_double) {
755       Diag(D, TSCLoc, diag::err_invalid_complex_spec)
756         << getSpecifierName((TST)TypeSpecType);
757       TypeSpecComplex = TSC_unspecified;
758     }
759   }
760 
761   // C++ [class.friend]p6:
762   //   No storage-class-specifier shall appear in the decl-specifier-seq
763   //   of a friend declaration.
764   if (isFriendSpecified() && getStorageClassSpec()) {
765     DeclSpec::SCS SC = getStorageClassSpec();
766     const char *SpecName = getSpecifierName(SC);
767 
768     SourceLocation SCLoc = getStorageClassSpecLoc();
769     SourceLocation SCEndLoc = SCLoc.getFileLocWithOffset(strlen(SpecName));
770 
771     Diag(D, SCLoc, diag::err_friend_storage_spec)
772       << SpecName
773       << FixItHint::CreateRemoval(SourceRange(SCLoc, SCEndLoc));
774 
775     ClearStorageClassSpecs();
776   }
777 
778   assert(!TypeSpecOwned || isDeclRep((TST) TypeSpecType));
779 
780   // Okay, now we can infer the real type.
781 
782   // TODO: return "auto function" and other bad things based on the real type.
783 
784   // 'data definition has no type or storage class'?
785 }
786 
787 bool DeclSpec::isMissingDeclaratorOk() {
788   TST tst = getTypeSpecType();
789   return isDeclRep(tst) && getRepAsDecl() != 0 &&
790     StorageClassSpec != DeclSpec::SCS_typedef;
791 }
792 
793 void UnqualifiedId::clear() {
794   if (Kind == IK_TemplateId)
795     TemplateId->Destroy();
796 
797   Kind = IK_Identifier;
798   Identifier = 0;
799   StartLocation = SourceLocation();
800   EndLocation = SourceLocation();
801 }
802 
803 void UnqualifiedId::setOperatorFunctionId(SourceLocation OperatorLoc,
804                                           OverloadedOperatorKind Op,
805                                           SourceLocation SymbolLocations[3]) {
806   Kind = IK_OperatorFunctionId;
807   StartLocation = OperatorLoc;
808   EndLocation = OperatorLoc;
809   OperatorFunctionId.Operator = Op;
810   for (unsigned I = 0; I != 3; ++I) {
811     OperatorFunctionId.SymbolLocations[I] = SymbolLocations[I].getRawEncoding();
812 
813     if (SymbolLocations[I].isValid())
814       EndLocation = SymbolLocations[I];
815   }
816 }
817 
818 bool VirtSpecifiers::SetSpecifier(Specifier VS, SourceLocation Loc,
819                                   const char *&PrevSpec) {
820   LastLocation = Loc;
821 
822   if (Specifiers & VS) {
823     PrevSpec = getSpecifierName(VS);
824     return true;
825   }
826 
827   Specifiers |= VS;
828 
829   switch (VS) {
830   default: assert(0 && "Unknown specifier!");
831   case VS_Override: VS_overrideLoc = Loc; break;
832   case VS_Final:    VS_finalLoc = Loc; break;
833   }
834 
835   return false;
836 }
837 
838 const char *VirtSpecifiers::getSpecifierName(Specifier VS) {
839   switch (VS) {
840   default: assert(0 && "Unknown specifier");
841   case VS_Override: return "override";
842   case VS_Final: return "final";
843   }
844 }
845