xref: /freebsd/contrib/llvm-project/clang/lib/Sema/DeclSpec.cpp (revision 8c2f6c3be0125142d3c1782e4b0ee0634c584b9e) 
1 //===--- DeclSpec.cpp - Declaration Specifier Semantic Analysis -----------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 //  This file implements semantic analysis for declaration specifiers.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/Sema/DeclSpec.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/DeclCXX.h"
16 #include "clang/AST/Expr.h"
17 #include "clang/AST/LocInfoType.h"
18 #include "clang/AST/TypeLoc.h"
19 #include "clang/Basic/LangOptions.h"
20 #include "clang/Basic/SourceManager.h"
21 #include "clang/Basic/Specifiers.h"
22 #include "clang/Basic/TargetInfo.h"
23 #include "clang/Sema/ParsedTemplate.h"
24 #include "clang/Sema/Sema.h"
25 #include "clang/Sema/SemaDiagnostic.h"
26 #include "llvm/ADT/STLExtras.h"
27 #include "llvm/ADT/SmallString.h"
28 #include <cstring>
29 using namespace clang;
30 
31 
32 void UnqualifiedId::setTemplateId(TemplateIdAnnotation *TemplateId) {
33   assert(TemplateId && "NULL template-id annotation?");
34   assert(!TemplateId->isInvalid() &&
35          "should not convert invalid template-ids to unqualified-ids");
36 
37   Kind = UnqualifiedIdKind::IK_TemplateId;
38   this->TemplateId = TemplateId;
39   StartLocation = TemplateId->TemplateNameLoc;
40   EndLocation = TemplateId->RAngleLoc;
41 }
42 
43 void UnqualifiedId::setConstructorTemplateId(TemplateIdAnnotation *TemplateId) {
44   assert(TemplateId && "NULL template-id annotation?");
45   assert(!TemplateId->isInvalid() &&
46          "should not convert invalid template-ids to unqualified-ids");
47 
48   Kind = UnqualifiedIdKind::IK_ConstructorTemplateId;
49   this->TemplateId = TemplateId;
50   StartLocation = TemplateId->TemplateNameLoc;
51   EndLocation = TemplateId->RAngleLoc;
52 }
53 
54 void CXXScopeSpec::Extend(ASTContext &Context, SourceLocation TemplateKWLoc,
55                           TypeLoc TL, SourceLocation ColonColonLoc) {
56   Builder.Extend(Context, TemplateKWLoc, TL, ColonColonLoc);
57   if (Range.getBegin().isInvalid())
58     Range.setBegin(TL.getBeginLoc());
59   Range.setEnd(ColonColonLoc);
60 
61   assert(Range == Builder.getSourceRange() &&
62          "NestedNameSpecifierLoc range computation incorrect");
63 }
64 
65 void CXXScopeSpec::Extend(ASTContext &Context, IdentifierInfo *Identifier,
66                           SourceLocation IdentifierLoc,
67                           SourceLocation ColonColonLoc) {
68   Builder.Extend(Context, Identifier, IdentifierLoc, ColonColonLoc);
69 
70   if (Range.getBegin().isInvalid())
71     Range.setBegin(IdentifierLoc);
72   Range.setEnd(ColonColonLoc);
73 
74   assert(Range == Builder.getSourceRange() &&
75          "NestedNameSpecifierLoc range computation incorrect");
76 }
77 
78 void CXXScopeSpec::Extend(ASTContext &Context, NamespaceDecl *Namespace,
79                           SourceLocation NamespaceLoc,
80                           SourceLocation ColonColonLoc) {
81   Builder.Extend(Context, Namespace, NamespaceLoc, ColonColonLoc);
82 
83   if (Range.getBegin().isInvalid())
84     Range.setBegin(NamespaceLoc);
85   Range.setEnd(ColonColonLoc);
86 
87   assert(Range == Builder.getSourceRange() &&
88          "NestedNameSpecifierLoc range computation incorrect");
89 }
90 
91 void CXXScopeSpec::Extend(ASTContext &Context, NamespaceAliasDecl *Alias,
92                           SourceLocation AliasLoc,
93                           SourceLocation ColonColonLoc) {
94   Builder.Extend(Context, Alias, AliasLoc, ColonColonLoc);
95 
96   if (Range.getBegin().isInvalid())
97     Range.setBegin(AliasLoc);
98   Range.setEnd(ColonColonLoc);
99 
100   assert(Range == Builder.getSourceRange() &&
101          "NestedNameSpecifierLoc range computation incorrect");
102 }
103 
104 void CXXScopeSpec::MakeGlobal(ASTContext &Context,
105                               SourceLocation ColonColonLoc) {
106   Builder.MakeGlobal(Context, ColonColonLoc);
107 
108   Range = SourceRange(ColonColonLoc);
109 
110   assert(Range == Builder.getSourceRange() &&
111          "NestedNameSpecifierLoc range computation incorrect");
112 }
113 
114 void CXXScopeSpec::MakeSuper(ASTContext &Context, CXXRecordDecl *RD,
115                              SourceLocation SuperLoc,
116                              SourceLocation ColonColonLoc) {
117   Builder.MakeSuper(Context, RD, SuperLoc, ColonColonLoc);
118 
119   Range.setBegin(SuperLoc);
120   Range.setEnd(ColonColonLoc);
121 
122   assert(Range == Builder.getSourceRange() &&
123   "NestedNameSpecifierLoc range computation incorrect");
124 }
125 
126 void CXXScopeSpec::MakeTrivial(ASTContext &Context,
127                                NestedNameSpecifier *Qualifier, SourceRange R) {
128   Builder.MakeTrivial(Context, Qualifier, R);
129   Range = R;
130 }
131 
132 void CXXScopeSpec::Adopt(NestedNameSpecifierLoc Other) {
133   if (!Other) {
134     Range = SourceRange();
135     Builder.Clear();
136     return;
137   }
138 
139   Range = Other.getSourceRange();
140   Builder.Adopt(Other);
141   assert(Range == Builder.getSourceRange() &&
142          "NestedNameSpecifierLoc range computation incorrect");
143 }
144 
145 SourceLocation CXXScopeSpec::getLastQualifierNameLoc() const {
146   if (!Builder.getRepresentation())
147     return SourceLocation();
148   return Builder.getTemporary().getLocalBeginLoc();
149 }
150 
151 NestedNameSpecifierLoc
152 CXXScopeSpec::getWithLocInContext(ASTContext &Context) const {
153   if (!Builder.getRepresentation())
154     return NestedNameSpecifierLoc();
155 
156   return Builder.getWithLocInContext(Context);
157 }
158 
159 /// DeclaratorChunk::getFunction - Return a DeclaratorChunk for a function.
160 /// "TheDeclarator" is the declarator that this will be added to.
161 DeclaratorChunk DeclaratorChunk::getFunction(bool hasProto,
162                                              bool isAmbiguous,
163                                              SourceLocation LParenLoc,
164                                              ParamInfo *Params,
165                                              unsigned NumParams,
166                                              SourceLocation EllipsisLoc,
167                                              SourceLocation RParenLoc,
168                                              bool RefQualifierIsLvalueRef,
169                                              SourceLocation RefQualifierLoc,
170                                              SourceLocation MutableLoc,
171                                              ExceptionSpecificationType
172                                                  ESpecType,
173                                              SourceRange ESpecRange,
174                                              ParsedType *Exceptions,
175                                              SourceRange *ExceptionRanges,
176                                              unsigned NumExceptions,
177                                              Expr *NoexceptExpr,
178                                              CachedTokens *ExceptionSpecTokens,
179                                              ArrayRef<NamedDecl*>
180                                                  DeclsInPrototype,
181                                              SourceLocation LocalRangeBegin,
182                                              SourceLocation LocalRangeEnd,
183                                              Declarator &TheDeclarator,
184                                              TypeResult TrailingReturnType,
185                                              SourceLocation
186                                                  TrailingReturnTypeLoc,
187                                              DeclSpec *MethodQualifiers) {
188   assert(!(MethodQualifiers && MethodQualifiers->getTypeQualifiers() & DeclSpec::TQ_atomic) &&
189          "function cannot have _Atomic qualifier");
190 
191   DeclaratorChunk I;
192   I.Kind                        = Function;
193   I.Loc                         = LocalRangeBegin;
194   I.EndLoc                      = LocalRangeEnd;
195   new (&I.Fun) FunctionTypeInfo;
196   I.Fun.hasPrototype            = hasProto;
197   I.Fun.isVariadic              = EllipsisLoc.isValid();
198   I.Fun.isAmbiguous             = isAmbiguous;
199   I.Fun.LParenLoc               = LParenLoc;
200   I.Fun.EllipsisLoc             = EllipsisLoc;
201   I.Fun.RParenLoc               = RParenLoc;
202   I.Fun.DeleteParams            = false;
203   I.Fun.NumParams               = NumParams;
204   I.Fun.Params                  = nullptr;
205   I.Fun.RefQualifierIsLValueRef = RefQualifierIsLvalueRef;
206   I.Fun.RefQualifierLoc         = RefQualifierLoc;
207   I.Fun.MutableLoc              = MutableLoc;
208   I.Fun.ExceptionSpecType       = ESpecType;
209   I.Fun.ExceptionSpecLocBeg     = ESpecRange.getBegin();
210   I.Fun.ExceptionSpecLocEnd     = ESpecRange.getEnd();
211   I.Fun.NumExceptionsOrDecls    = 0;
212   I.Fun.Exceptions              = nullptr;
213   I.Fun.NoexceptExpr            = nullptr;
214   I.Fun.HasTrailingReturnType   = TrailingReturnType.isUsable() ||
215                                   TrailingReturnType.isInvalid();
216   I.Fun.TrailingReturnType      = TrailingReturnType.get();
217   I.Fun.TrailingReturnTypeLoc   = TrailingReturnTypeLoc;
218   I.Fun.MethodQualifiers        = nullptr;
219   I.Fun.QualAttrFactory         = nullptr;
220 
221   if (MethodQualifiers && (MethodQualifiers->getTypeQualifiers() ||
222                            MethodQualifiers->getAttributes().size())) {
223     auto &attrs = MethodQualifiers->getAttributes();
224     I.Fun.MethodQualifiers = new DeclSpec(attrs.getPool().getFactory());
225     MethodQualifiers->forEachCVRUQualifier(
226         [&](DeclSpec::TQ TypeQual, StringRef PrintName, SourceLocation SL) {
227           I.Fun.MethodQualifiers->SetTypeQual(TypeQual, SL);
228         });
229     I.Fun.MethodQualifiers->getAttributes().takeAllFrom(attrs);
230     I.Fun.MethodQualifiers->getAttributePool().takeAllFrom(attrs.getPool());
231   }
232 
233   assert(I.Fun.ExceptionSpecType == ESpecType && "bitfield overflow");
234 
235   // new[] a parameter array if needed.
236   if (NumParams) {
237     // If the 'InlineParams' in Declarator is unused and big enough, put our
238     // parameter list there (in an effort to avoid new/delete traffic).  If it
239     // is already used (consider a function returning a function pointer) or too
240     // small (function with too many parameters), go to the heap.
241     if (!TheDeclarator.InlineStorageUsed &&
242         NumParams <= std::size(TheDeclarator.InlineParams)) {
243       I.Fun.Params = TheDeclarator.InlineParams;
244       new (I.Fun.Params) ParamInfo[NumParams];
245       I.Fun.DeleteParams = false;
246       TheDeclarator.InlineStorageUsed = true;
247     } else {
248       I.Fun.Params = new DeclaratorChunk::ParamInfo[NumParams];
249       I.Fun.DeleteParams = true;
250     }
251     for (unsigned i = 0; i < NumParams; i++)
252       I.Fun.Params[i] = std::move(Params[i]);
253   }
254 
255   // Check what exception specification information we should actually store.
256   switch (ESpecType) {
257   default: break; // By default, save nothing.
258   case EST_Dynamic:
259     // new[] an exception array if needed
260     if (NumExceptions) {
261       I.Fun.NumExceptionsOrDecls = NumExceptions;
262       I.Fun.Exceptions = new DeclaratorChunk::TypeAndRange[NumExceptions];
263       for (unsigned i = 0; i != NumExceptions; ++i) {
264         I.Fun.Exceptions[i].Ty = Exceptions[i];
265         I.Fun.Exceptions[i].Range = ExceptionRanges[i];
266       }
267     }
268     break;
269 
270   case EST_DependentNoexcept:
271   case EST_NoexceptFalse:
272   case EST_NoexceptTrue:
273     I.Fun.NoexceptExpr = NoexceptExpr;
274     break;
275 
276   case EST_Unparsed:
277     I.Fun.ExceptionSpecTokens = ExceptionSpecTokens;
278     break;
279   }
280 
281   if (!DeclsInPrototype.empty()) {
282     assert(ESpecType == EST_None && NumExceptions == 0 &&
283            "cannot have exception specifiers and decls in prototype");
284     I.Fun.NumExceptionsOrDecls = DeclsInPrototype.size();
285     // Copy the array of decls into stable heap storage.
286     I.Fun.DeclsInPrototype = new NamedDecl *[DeclsInPrototype.size()];
287     for (size_t J = 0; J < DeclsInPrototype.size(); ++J)
288       I.Fun.DeclsInPrototype[J] = DeclsInPrototype[J];
289   }
290 
291   return I;
292 }
293 
294 void Declarator::setDecompositionBindings(
295     SourceLocation LSquareLoc,
296     ArrayRef<DecompositionDeclarator::Binding> Bindings,
297     SourceLocation RSquareLoc) {
298   assert(!hasName() && "declarator given multiple names!");
299 
300   BindingGroup.LSquareLoc = LSquareLoc;
301   BindingGroup.RSquareLoc = RSquareLoc;
302   BindingGroup.NumBindings = Bindings.size();
303   Range.setEnd(RSquareLoc);
304 
305   // We're now past the identifier.
306   SetIdentifier(nullptr, LSquareLoc);
307   Name.EndLocation = RSquareLoc;
308 
309   // Allocate storage for bindings and stash them away.
310   if (Bindings.size()) {
311     if (!InlineStorageUsed && Bindings.size() <= std::size(InlineBindings)) {
312       BindingGroup.Bindings = InlineBindings;
313       BindingGroup.DeleteBindings = false;
314       InlineStorageUsed = true;
315     } else {
316       BindingGroup.Bindings =
317           new DecompositionDeclarator::Binding[Bindings.size()];
318       BindingGroup.DeleteBindings = true;
319     }
320     std::uninitialized_copy(Bindings.begin(), Bindings.end(),
321                             BindingGroup.Bindings);
322   }
323 }
324 
325 bool Declarator::isDeclarationOfFunction() const {
326   for (unsigned i = 0, i_end = DeclTypeInfo.size(); i < i_end; ++i) {
327     switch (DeclTypeInfo[i].Kind) {
328     case DeclaratorChunk::Function:
329       return true;
330     case DeclaratorChunk::Paren:
331       continue;
332     case DeclaratorChunk::Pointer:
333     case DeclaratorChunk::Reference:
334     case DeclaratorChunk::Array:
335     case DeclaratorChunk::BlockPointer:
336     case DeclaratorChunk::MemberPointer:
337     case DeclaratorChunk::Pipe:
338       return false;
339     }
340     llvm_unreachable("Invalid type chunk");
341   }
342 
343   switch (DS.getTypeSpecType()) {
344     case TST_atomic:
345     case TST_auto:
346     case TST_auto_type:
347     case TST_bool:
348     case TST_char:
349     case TST_char8:
350     case TST_char16:
351     case TST_char32:
352     case TST_class:
353     case TST_decimal128:
354     case TST_decimal32:
355     case TST_decimal64:
356     case TST_double:
357     case TST_Accum:
358     case TST_Fract:
359     case TST_Float16:
360     case TST_float128:
361     case TST_ibm128:
362     case TST_enum:
363     case TST_error:
364     case TST_float:
365     case TST_half:
366     case TST_int:
367     case TST_int128:
368     case TST_bitint:
369     case TST_struct:
370     case TST_interface:
371     case TST_union:
372     case TST_unknown_anytype:
373     case TST_unspecified:
374     case TST_void:
375     case TST_wchar:
376     case TST_BFloat16:
377 #define GENERIC_IMAGE_TYPE(ImgType, Id) case TST_##ImgType##_t:
378 #include "clang/Basic/OpenCLImageTypes.def"
379       return false;
380 
381     case TST_decltype_auto:
382       // This must have an initializer, so can't be a function declaration,
383       // even if the initializer has function type.
384       return false;
385 
386     case TST_decltype:
387     case TST_typeof_unqualExpr:
388     case TST_typeofExpr:
389       if (Expr *E = DS.getRepAsExpr())
390         return E->getType()->isFunctionType();
391       return false;
392 
393 #define TRANSFORM_TYPE_TRAIT_DEF(_, Trait) case TST_##Trait:
394 #include "clang/Basic/TransformTypeTraits.def"
395     case TST_typename:
396     case TST_typeof_unqualType:
397     case TST_typeofType: {
398       QualType QT = DS.getRepAsType().get();
399       if (QT.isNull())
400         return false;
401 
402       if (const LocInfoType *LIT = dyn_cast<LocInfoType>(QT))
403         QT = LIT->getType();
404 
405       if (QT.isNull())
406         return false;
407 
408       return QT->isFunctionType();
409     }
410   }
411 
412   llvm_unreachable("Invalid TypeSpecType!");
413 }
414 
415 bool Declarator::isStaticMember() {
416   assert(getContext() == DeclaratorContext::Member);
417   return getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_static ||
418          (getName().getKind() == UnqualifiedIdKind::IK_OperatorFunctionId &&
419           CXXMethodDecl::isStaticOverloadedOperator(
420               getName().OperatorFunctionId.Operator));
421 }
422 
423 bool Declarator::isExplicitObjectMemberFunction() {
424   if (!isFunctionDeclarator())
425     return false;
426   DeclaratorChunk::FunctionTypeInfo &Fun = getFunctionTypeInfo();
427   if (Fun.NumParams) {
428     auto *P = dyn_cast_or_null<ParmVarDecl>(Fun.Params[0].Param);
429     if (P && P->isExplicitObjectParameter())
430       return true;
431   }
432   return false;
433 }
434 
435 bool Declarator::isCtorOrDtor() {
436   return (getName().getKind() == UnqualifiedIdKind::IK_ConstructorName) ||
437          (getName().getKind() == UnqualifiedIdKind::IK_DestructorName);
438 }
439 
440 void DeclSpec::forEachCVRUQualifier(
441     llvm::function_ref<void(TQ, StringRef, SourceLocation)> Handle) {
442   if (TypeQualifiers & TQ_const)
443     Handle(TQ_const, "const", TQ_constLoc);
444   if (TypeQualifiers & TQ_volatile)
445     Handle(TQ_volatile, "volatile", TQ_volatileLoc);
446   if (TypeQualifiers & TQ_restrict)
447     Handle(TQ_restrict, "restrict", TQ_restrictLoc);
448   if (TypeQualifiers & TQ_unaligned)
449     Handle(TQ_unaligned, "unaligned", TQ_unalignedLoc);
450 }
451 
452 void DeclSpec::forEachQualifier(
453     llvm::function_ref<void(TQ, StringRef, SourceLocation)> Handle) {
454   forEachCVRUQualifier(Handle);
455   // FIXME: Add code below to iterate through the attributes and call Handle.
456 }
457 
458 bool DeclSpec::hasTagDefinition() const {
459   if (!TypeSpecOwned)
460     return false;
461   return cast<TagDecl>(getRepAsDecl())->isCompleteDefinition();
462 }
463 
464 /// getParsedSpecifiers - Return a bitmask of which flavors of specifiers this
465 /// declaration specifier includes.
466 ///
467 unsigned DeclSpec::getParsedSpecifiers() const {
468   unsigned Res = 0;
469   if (StorageClassSpec != SCS_unspecified ||
470       ThreadStorageClassSpec != TSCS_unspecified)
471     Res |= PQ_StorageClassSpecifier;
472 
473   if (TypeQualifiers != TQ_unspecified)
474     Res |= PQ_TypeQualifier;
475 
476   if (hasTypeSpecifier())
477     Res |= PQ_TypeSpecifier;
478 
479   if (FS_inline_specified || FS_virtual_specified || hasExplicitSpecifier() ||
480       FS_noreturn_specified || FS_forceinline_specified)
481     Res |= PQ_FunctionSpecifier;
482   return Res;
483 }
484 
485 template <class T> static bool BadSpecifier(T TNew, T TPrev,
486                                             const char *&PrevSpec,
487                                             unsigned &DiagID,
488                                             bool IsExtension = true) {
489   PrevSpec = DeclSpec::getSpecifierName(TPrev);
490   if (TNew != TPrev)
491     DiagID = diag::err_invalid_decl_spec_combination;
492   else
493     DiagID = IsExtension ? diag::ext_warn_duplicate_declspec :
494                            diag::warn_duplicate_declspec;
495   return true;
496 }
497 
498 const char *DeclSpec::getSpecifierName(DeclSpec::SCS S) {
499   switch (S) {
500   case DeclSpec::SCS_unspecified: return "unspecified";
501   case DeclSpec::SCS_typedef:     return "typedef";
502   case DeclSpec::SCS_extern:      return "extern";
503   case DeclSpec::SCS_static:      return "static";
504   case DeclSpec::SCS_auto:        return "auto";
505   case DeclSpec::SCS_register:    return "register";
506   case DeclSpec::SCS_private_extern: return "__private_extern__";
507   case DeclSpec::SCS_mutable:     return "mutable";
508   }
509   llvm_unreachable("Unknown typespec!");
510 }
511 
512 const char *DeclSpec::getSpecifierName(DeclSpec::TSCS S) {
513   switch (S) {
514   case DeclSpec::TSCS_unspecified:   return "unspecified";
515   case DeclSpec::TSCS___thread:      return "__thread";
516   case DeclSpec::TSCS_thread_local:  return "thread_local";
517   case DeclSpec::TSCS__Thread_local: return "_Thread_local";
518   }
519   llvm_unreachable("Unknown typespec!");
520 }
521 
522 const char *DeclSpec::getSpecifierName(TypeSpecifierWidth W) {
523   switch (W) {
524   case TypeSpecifierWidth::Unspecified:
525     return "unspecified";
526   case TypeSpecifierWidth::Short:
527     return "short";
528   case TypeSpecifierWidth::Long:
529     return "long";
530   case TypeSpecifierWidth::LongLong:
531     return "long long";
532   }
533   llvm_unreachable("Unknown typespec!");
534 }
535 
536 const char *DeclSpec::getSpecifierName(TSC C) {
537   switch (C) {
538   case TSC_unspecified: return "unspecified";
539   case TSC_imaginary:   return "imaginary";
540   case TSC_complex:     return "complex";
541   }
542   llvm_unreachable("Unknown typespec!");
543 }
544 
545 const char *DeclSpec::getSpecifierName(TypeSpecifierSign S) {
546   switch (S) {
547   case TypeSpecifierSign::Unspecified:
548     return "unspecified";
549   case TypeSpecifierSign::Signed:
550     return "signed";
551   case TypeSpecifierSign::Unsigned:
552     return "unsigned";
553   }
554   llvm_unreachable("Unknown typespec!");
555 }
556 
557 const char *DeclSpec::getSpecifierName(DeclSpec::TST T,
558                                        const PrintingPolicy &Policy) {
559   switch (T) {
560   case DeclSpec::TST_unspecified: return "unspecified";
561   case DeclSpec::TST_void:        return "void";
562   case DeclSpec::TST_char:        return "char";
563   case DeclSpec::TST_wchar:       return Policy.MSWChar ? "__wchar_t" : "wchar_t";
564   case DeclSpec::TST_char8:       return "char8_t";
565   case DeclSpec::TST_char16:      return "char16_t";
566   case DeclSpec::TST_char32:      return "char32_t";
567   case DeclSpec::TST_int:         return "int";
568   case DeclSpec::TST_int128:      return "__int128";
569   case DeclSpec::TST_bitint:      return "_BitInt";
570   case DeclSpec::TST_half:        return "half";
571   case DeclSpec::TST_float:       return "float";
572   case DeclSpec::TST_double:      return "double";
573   case DeclSpec::TST_accum:       return "_Accum";
574   case DeclSpec::TST_fract:       return "_Fract";
575   case DeclSpec::TST_float16:     return "_Float16";
576   case DeclSpec::TST_float128:    return "__float128";
577   case DeclSpec::TST_ibm128:      return "__ibm128";
578   case DeclSpec::TST_bool:        return Policy.Bool ? "bool" : "_Bool";
579   case DeclSpec::TST_decimal32:   return "_Decimal32";
580   case DeclSpec::TST_decimal64:   return "_Decimal64";
581   case DeclSpec::TST_decimal128:  return "_Decimal128";
582   case DeclSpec::TST_enum:        return "enum";
583   case DeclSpec::TST_class:       return "class";
584   case DeclSpec::TST_union:       return "union";
585   case DeclSpec::TST_struct:      return "struct";
586   case DeclSpec::TST_interface:   return "__interface";
587   case DeclSpec::TST_typename:    return "type-name";
588   case DeclSpec::TST_typeofType:
589   case DeclSpec::TST_typeofExpr:  return "typeof";
590   case DeclSpec::TST_typeof_unqualType:
591   case DeclSpec::TST_typeof_unqualExpr: return "typeof_unqual";
592   case DeclSpec::TST_auto:        return "auto";
593   case DeclSpec::TST_auto_type:   return "__auto_type";
594   case DeclSpec::TST_decltype:    return "(decltype)";
595   case DeclSpec::TST_decltype_auto: return "decltype(auto)";
596 #define TRANSFORM_TYPE_TRAIT_DEF(_, Trait)                                     \
597   case DeclSpec::TST_##Trait:                                                  \
598     return "__" #Trait;
599 #include "clang/Basic/TransformTypeTraits.def"
600   case DeclSpec::TST_unknown_anytype: return "__unknown_anytype";
601   case DeclSpec::TST_atomic: return "_Atomic";
602   case DeclSpec::TST_BFloat16: return "__bf16";
603 #define GENERIC_IMAGE_TYPE(ImgType, Id) \
604   case DeclSpec::TST_##ImgType##_t: \
605     return #ImgType "_t";
606 #include "clang/Basic/OpenCLImageTypes.def"
607   case DeclSpec::TST_error:       return "(error)";
608   }
609   llvm_unreachable("Unknown typespec!");
610 }
611 
612 const char *DeclSpec::getSpecifierName(ConstexprSpecKind C) {
613   switch (C) {
614   case ConstexprSpecKind::Unspecified:
615     return "unspecified";
616   case ConstexprSpecKind::Constexpr:
617     return "constexpr";
618   case ConstexprSpecKind::Consteval:
619     return "consteval";
620   case ConstexprSpecKind::Constinit:
621     return "constinit";
622   }
623   llvm_unreachable("Unknown ConstexprSpecKind");
624 }
625 
626 const char *DeclSpec::getSpecifierName(TQ T) {
627   switch (T) {
628   case DeclSpec::TQ_unspecified: return "unspecified";
629   case DeclSpec::TQ_const:       return "const";
630   case DeclSpec::TQ_restrict:    return "restrict";
631   case DeclSpec::TQ_volatile:    return "volatile";
632   case DeclSpec::TQ_atomic:      return "_Atomic";
633   case DeclSpec::TQ_unaligned:   return "__unaligned";
634   }
635   llvm_unreachable("Unknown typespec!");
636 }
637 
638 bool DeclSpec::SetStorageClassSpec(Sema &S, SCS SC, SourceLocation Loc,
639                                    const char *&PrevSpec,
640                                    unsigned &DiagID,
641                                    const PrintingPolicy &Policy) {
642   // OpenCL v1.1 s6.8g: "The extern, static, auto and register storage-class
643   // specifiers are not supported.
644   // It seems sensible to prohibit private_extern too
645   // The cl_clang_storage_class_specifiers extension enables support for
646   // these storage-class specifiers.
647   // OpenCL v1.2 s6.8 changes this to "The auto and register storage-class
648   // specifiers are not supported."
649   if (S.getLangOpts().OpenCL &&
650       !S.getOpenCLOptions().isAvailableOption(
651           "cl_clang_storage_class_specifiers", S.getLangOpts())) {
652     switch (SC) {
653     case SCS_extern:
654     case SCS_private_extern:
655     case SCS_static:
656       if (S.getLangOpts().getOpenCLCompatibleVersion() < 120) {
657         DiagID = diag::err_opencl_unknown_type_specifier;
658         PrevSpec = getSpecifierName(SC);
659         return true;
660       }
661       break;
662     case SCS_auto:
663     case SCS_register:
664       DiagID   = diag::err_opencl_unknown_type_specifier;
665       PrevSpec = getSpecifierName(SC);
666       return true;
667     default:
668       break;
669     }
670   }
671 
672   if (StorageClassSpec != SCS_unspecified) {
673     // Maybe this is an attempt to use C++11 'auto' outside of C++11 mode.
674     bool isInvalid = true;
675     if (TypeSpecType == TST_unspecified && S.getLangOpts().CPlusPlus) {
676       if (SC == SCS_auto)
677         return SetTypeSpecType(TST_auto, Loc, PrevSpec, DiagID, Policy);
678       if (StorageClassSpec == SCS_auto) {
679         isInvalid = SetTypeSpecType(TST_auto, StorageClassSpecLoc,
680                                     PrevSpec, DiagID, Policy);
681         assert(!isInvalid && "auto SCS -> TST recovery failed");
682       }
683     }
684 
685     // Changing storage class is allowed only if the previous one
686     // was the 'extern' that is part of a linkage specification and
687     // the new storage class is 'typedef'.
688     if (isInvalid &&
689         !(SCS_extern_in_linkage_spec &&
690           StorageClassSpec == SCS_extern &&
691           SC == SCS_typedef))
692       return BadSpecifier(SC, (SCS)StorageClassSpec, PrevSpec, DiagID);
693   }
694   StorageClassSpec = SC;
695   StorageClassSpecLoc = Loc;
696   assert((unsigned)SC == StorageClassSpec && "SCS constants overflow bitfield");
697   return false;
698 }
699 
700 bool DeclSpec::SetStorageClassSpecThread(TSCS TSC, SourceLocation Loc,
701                                          const char *&PrevSpec,
702                                          unsigned &DiagID) {
703   if (ThreadStorageClassSpec != TSCS_unspecified)
704     return BadSpecifier(TSC, (TSCS)ThreadStorageClassSpec, PrevSpec, DiagID);
705 
706   ThreadStorageClassSpec = TSC;
707   ThreadStorageClassSpecLoc = Loc;
708   return false;
709 }
710 
711 /// These methods set the specified attribute of the DeclSpec, but return true
712 /// and ignore the request if invalid (e.g. "extern" then "auto" is
713 /// specified).
714 bool DeclSpec::SetTypeSpecWidth(TypeSpecifierWidth W, SourceLocation Loc,
715                                 const char *&PrevSpec, unsigned &DiagID,
716                                 const PrintingPolicy &Policy) {
717   // Overwrite TSWRange.Begin only if TypeSpecWidth was unspecified, so that
718   // for 'long long' we will keep the source location of the first 'long'.
719   if (getTypeSpecWidth() == TypeSpecifierWidth::Unspecified)
720     TSWRange.setBegin(Loc);
721   // Allow turning long -> long long.
722   else if (W != TypeSpecifierWidth::LongLong ||
723            getTypeSpecWidth() != TypeSpecifierWidth::Long)
724     return BadSpecifier(W, getTypeSpecWidth(), PrevSpec, DiagID);
725   TypeSpecWidth = static_cast<unsigned>(W);
726   // Remember location of the last 'long'
727   TSWRange.setEnd(Loc);
728   return false;
729 }
730 
731 bool DeclSpec::SetTypeSpecComplex(TSC C, SourceLocation Loc,
732                                   const char *&PrevSpec,
733                                   unsigned &DiagID) {
734   if (TypeSpecComplex != TSC_unspecified)
735     return BadSpecifier(C, (TSC)TypeSpecComplex, PrevSpec, DiagID);
736   TypeSpecComplex = C;
737   TSCLoc = Loc;
738   return false;
739 }
740 
741 bool DeclSpec::SetTypeSpecSign(TypeSpecifierSign S, SourceLocation Loc,
742                                const char *&PrevSpec, unsigned &DiagID) {
743   if (getTypeSpecSign() != TypeSpecifierSign::Unspecified)
744     return BadSpecifier(S, getTypeSpecSign(), PrevSpec, DiagID);
745   TypeSpecSign = static_cast<unsigned>(S);
746   TSSLoc = Loc;
747   return false;
748 }
749 
750 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
751                                const char *&PrevSpec,
752                                unsigned &DiagID,
753                                ParsedType Rep,
754                                const PrintingPolicy &Policy) {
755   return SetTypeSpecType(T, Loc, Loc, PrevSpec, DiagID, Rep, Policy);
756 }
757 
758 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation TagKwLoc,
759                                SourceLocation TagNameLoc,
760                                const char *&PrevSpec,
761                                unsigned &DiagID,
762                                ParsedType Rep,
763                                const PrintingPolicy &Policy) {
764   assert(isTypeRep(T) && "T does not store a type");
765   assert(Rep && "no type provided!");
766   if (TypeSpecType == TST_error)
767     return false;
768   if (TypeSpecType != TST_unspecified) {
769     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
770     DiagID = diag::err_invalid_decl_spec_combination;
771     return true;
772   }
773   TypeSpecType = T;
774   TypeRep = Rep;
775   TSTLoc = TagKwLoc;
776   TSTNameLoc = TagNameLoc;
777   TypeSpecOwned = false;
778   return false;
779 }
780 
781 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
782                                const char *&PrevSpec,
783                                unsigned &DiagID,
784                                Expr *Rep,
785                                const PrintingPolicy &Policy) {
786   assert(isExprRep(T) && "T does not store an expr");
787   assert(Rep && "no expression provided!");
788   if (TypeSpecType == TST_error)
789     return false;
790   if (TypeSpecType != TST_unspecified) {
791     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
792     DiagID = diag::err_invalid_decl_spec_combination;
793     return true;
794   }
795   TypeSpecType = T;
796   ExprRep = Rep;
797   TSTLoc = Loc;
798   TSTNameLoc = Loc;
799   TypeSpecOwned = false;
800   return false;
801 }
802 
803 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
804                                const char *&PrevSpec,
805                                unsigned &DiagID,
806                                Decl *Rep, bool Owned,
807                                const PrintingPolicy &Policy) {
808   return SetTypeSpecType(T, Loc, Loc, PrevSpec, DiagID, Rep, Owned, Policy);
809 }
810 
811 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation TagKwLoc,
812                                SourceLocation TagNameLoc,
813                                const char *&PrevSpec,
814                                unsigned &DiagID,
815                                Decl *Rep, bool Owned,
816                                const PrintingPolicy &Policy) {
817   assert(isDeclRep(T) && "T does not store a decl");
818   // Unlike the other cases, we don't assert that we actually get a decl.
819 
820   if (TypeSpecType == TST_error)
821     return false;
822   if (TypeSpecType != TST_unspecified) {
823     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
824     DiagID = diag::err_invalid_decl_spec_combination;
825     return true;
826   }
827   TypeSpecType = T;
828   DeclRep = Rep;
829   TSTLoc = TagKwLoc;
830   TSTNameLoc = TagNameLoc;
831   TypeSpecOwned = Owned && Rep != nullptr;
832   return false;
833 }
834 
835 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc, const char *&PrevSpec,
836                                unsigned &DiagID, TemplateIdAnnotation *Rep,
837                                const PrintingPolicy &Policy) {
838   assert(T == TST_auto || T == TST_decltype_auto);
839   ConstrainedAuto = true;
840   TemplateIdRep = Rep;
841   return SetTypeSpecType(T, Loc, PrevSpec, DiagID, Policy);
842 }
843 
844 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
845                                const char *&PrevSpec,
846                                unsigned &DiagID,
847                                const PrintingPolicy &Policy) {
848   assert(!isDeclRep(T) && !isTypeRep(T) && !isExprRep(T) &&
849          "rep required for these type-spec kinds!");
850   if (TypeSpecType == TST_error)
851     return false;
852   if (TypeSpecType != TST_unspecified) {
853     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
854     DiagID = diag::err_invalid_decl_spec_combination;
855     return true;
856   }
857   TSTLoc = Loc;
858   TSTNameLoc = Loc;
859   if (TypeAltiVecVector && (T == TST_bool) && !TypeAltiVecBool) {
860     TypeAltiVecBool = true;
861     return false;
862   }
863   TypeSpecType = T;
864   TypeSpecOwned = false;
865   return false;
866 }
867 
868 bool DeclSpec::SetTypeSpecSat(SourceLocation Loc, const char *&PrevSpec,
869                               unsigned &DiagID) {
870   // Cannot set twice
871   if (TypeSpecSat) {
872     DiagID = diag::warn_duplicate_declspec;
873     PrevSpec = "_Sat";
874     return true;
875   }
876   TypeSpecSat = true;
877   TSSatLoc = Loc;
878   return false;
879 }
880 
881 bool DeclSpec::SetTypeAltiVecVector(bool isAltiVecVector, SourceLocation Loc,
882                           const char *&PrevSpec, unsigned &DiagID,
883                           const PrintingPolicy &Policy) {
884   if (TypeSpecType == TST_error)
885     return false;
886   if (TypeSpecType != TST_unspecified) {
887     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
888     DiagID = diag::err_invalid_vector_decl_spec_combination;
889     return true;
890   }
891   TypeAltiVecVector = isAltiVecVector;
892   AltiVecLoc = Loc;
893   return false;
894 }
895 
896 bool DeclSpec::SetTypePipe(bool isPipe, SourceLocation Loc,
897                            const char *&PrevSpec, unsigned &DiagID,
898                            const PrintingPolicy &Policy) {
899   if (TypeSpecType == TST_error)
900     return false;
901   if (TypeSpecType != TST_unspecified) {
902     PrevSpec = DeclSpec::getSpecifierName((TST)TypeSpecType, Policy);
903     DiagID = diag::err_invalid_decl_spec_combination;
904     return true;
905   }
906 
907   if (isPipe) {
908     TypeSpecPipe = static_cast<unsigned>(TypeSpecifiersPipe::Pipe);
909   }
910   return false;
911 }
912 
913 bool DeclSpec::SetTypeAltiVecPixel(bool isAltiVecPixel, SourceLocation Loc,
914                           const char *&PrevSpec, unsigned &DiagID,
915                           const PrintingPolicy &Policy) {
916   if (TypeSpecType == TST_error)
917     return false;
918   if (!TypeAltiVecVector || TypeAltiVecPixel ||
919       (TypeSpecType != TST_unspecified)) {
920     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
921     DiagID = diag::err_invalid_pixel_decl_spec_combination;
922     return true;
923   }
924   TypeAltiVecPixel = isAltiVecPixel;
925   TSTLoc = Loc;
926   TSTNameLoc = Loc;
927   return false;
928 }
929 
930 bool DeclSpec::SetTypeAltiVecBool(bool isAltiVecBool, SourceLocation Loc,
931                                   const char *&PrevSpec, unsigned &DiagID,
932                                   const PrintingPolicy &Policy) {
933   if (TypeSpecType == TST_error)
934     return false;
935   if (!TypeAltiVecVector || TypeAltiVecBool ||
936       (TypeSpecType != TST_unspecified)) {
937     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
938     DiagID = diag::err_invalid_vector_bool_decl_spec;
939     return true;
940   }
941   TypeAltiVecBool = isAltiVecBool;
942   TSTLoc = Loc;
943   TSTNameLoc = Loc;
944   return false;
945 }
946 
947 bool DeclSpec::SetTypeSpecError() {
948   TypeSpecType = TST_error;
949   TypeSpecOwned = false;
950   TSTLoc = SourceLocation();
951   TSTNameLoc = SourceLocation();
952   return false;
953 }
954 
955 bool DeclSpec::SetBitIntType(SourceLocation KWLoc, Expr *BitsExpr,
956                              const char *&PrevSpec, unsigned &DiagID,
957                              const PrintingPolicy &Policy) {
958   assert(BitsExpr && "no expression provided!");
959   if (TypeSpecType == TST_error)
960     return false;
961 
962   if (TypeSpecType != TST_unspecified) {
963     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
964     DiagID = diag::err_invalid_decl_spec_combination;
965     return true;
966   }
967 
968   TypeSpecType = TST_bitint;
969   ExprRep = BitsExpr;
970   TSTLoc = KWLoc;
971   TSTNameLoc = KWLoc;
972   TypeSpecOwned = false;
973   return false;
974 }
975 
976 bool DeclSpec::SetTypeQual(TQ T, SourceLocation Loc, const char *&PrevSpec,
977                            unsigned &DiagID, const LangOptions &Lang) {
978   // Duplicates are permitted in C99 onwards, but are not permitted in C89 or
979   // C++.  However, since this is likely not what the user intended, we will
980   // always warn.  We do not need to set the qualifier's location since we
981   // already have it.
982   if (TypeQualifiers & T) {
983     bool IsExtension = true;
984     if (Lang.C99)
985       IsExtension = false;
986     return BadSpecifier(T, T, PrevSpec, DiagID, IsExtension);
987   }
988 
989   return SetTypeQual(T, Loc);
990 }
991 
992 bool DeclSpec::SetTypeQual(TQ T, SourceLocation Loc) {
993   TypeQualifiers |= T;
994 
995   switch (T) {
996   case TQ_unspecified: break;
997   case TQ_const:    TQ_constLoc = Loc; return false;
998   case TQ_restrict: TQ_restrictLoc = Loc; return false;
999   case TQ_volatile: TQ_volatileLoc = Loc; return false;
1000   case TQ_unaligned: TQ_unalignedLoc = Loc; return false;
1001   case TQ_atomic:   TQ_atomicLoc = Loc; return false;
1002   }
1003 
1004   llvm_unreachable("Unknown type qualifier!");
1005 }
1006 
1007 bool DeclSpec::setFunctionSpecInline(SourceLocation Loc, const char *&PrevSpec,
1008                                      unsigned &DiagID) {
1009   // 'inline inline' is ok.  However, since this is likely not what the user
1010   // intended, we will always warn, similar to duplicates of type qualifiers.
1011   if (FS_inline_specified) {
1012     DiagID = diag::warn_duplicate_declspec;
1013     PrevSpec = "inline";
1014     return true;
1015   }
1016   FS_inline_specified = true;
1017   FS_inlineLoc = Loc;
1018   return false;
1019 }
1020 
1021 bool DeclSpec::setFunctionSpecForceInline(SourceLocation Loc, const char *&PrevSpec,
1022                                           unsigned &DiagID) {
1023   if (FS_forceinline_specified) {
1024     DiagID = diag::warn_duplicate_declspec;
1025     PrevSpec = "__forceinline";
1026     return true;
1027   }
1028   FS_forceinline_specified = true;
1029   FS_forceinlineLoc = Loc;
1030   return false;
1031 }
1032 
1033 bool DeclSpec::setFunctionSpecVirtual(SourceLocation Loc,
1034                                       const char *&PrevSpec,
1035                                       unsigned &DiagID) {
1036   // 'virtual virtual' is ok, but warn as this is likely not what the user
1037   // intended.
1038   if (FS_virtual_specified) {
1039     DiagID = diag::warn_duplicate_declspec;
1040     PrevSpec = "virtual";
1041     return true;
1042   }
1043   FS_virtual_specified = true;
1044   FS_virtualLoc = Loc;
1045   return false;
1046 }
1047 
1048 bool DeclSpec::setFunctionSpecExplicit(SourceLocation Loc,
1049                                        const char *&PrevSpec, unsigned &DiagID,
1050                                        ExplicitSpecifier ExplicitSpec,
1051                                        SourceLocation CloseParenLoc) {
1052   // 'explicit explicit' is ok, but warn as this is likely not what the user
1053   // intended.
1054   if (hasExplicitSpecifier()) {
1055     DiagID = (ExplicitSpec.getExpr() || FS_explicit_specifier.getExpr())
1056                  ? diag::err_duplicate_declspec
1057                  : diag::ext_warn_duplicate_declspec;
1058     PrevSpec = "explicit";
1059     return true;
1060   }
1061   FS_explicit_specifier = ExplicitSpec;
1062   FS_explicitLoc = Loc;
1063   FS_explicitCloseParenLoc = CloseParenLoc;
1064   return false;
1065 }
1066 
1067 bool DeclSpec::setFunctionSpecNoreturn(SourceLocation Loc,
1068                                        const char *&PrevSpec,
1069                                        unsigned &DiagID) {
1070   // '_Noreturn _Noreturn' is ok, but warn as this is likely not what the user
1071   // intended.
1072   if (FS_noreturn_specified) {
1073     DiagID = diag::warn_duplicate_declspec;
1074     PrevSpec = "_Noreturn";
1075     return true;
1076   }
1077   FS_noreturn_specified = true;
1078   FS_noreturnLoc = Loc;
1079   return false;
1080 }
1081 
1082 bool DeclSpec::SetFriendSpec(SourceLocation Loc, const char *&PrevSpec,
1083                              unsigned &DiagID) {
1084   if (Friend_specified) {
1085     PrevSpec = "friend";
1086     // Keep the later location, so that we can later diagnose ill-formed
1087     // declarations like 'friend class X friend;'. Per [class.friend]p3,
1088     // 'friend' must be the first token in a friend declaration that is
1089     // not a function declaration.
1090     FriendLoc = Loc;
1091     DiagID = diag::warn_duplicate_declspec;
1092     return true;
1093   }
1094 
1095   Friend_specified = true;
1096   FriendLoc = Loc;
1097   return false;
1098 }
1099 
1100 bool DeclSpec::setModulePrivateSpec(SourceLocation Loc, const char *&PrevSpec,
1101                                     unsigned &DiagID) {
1102   if (isModulePrivateSpecified()) {
1103     PrevSpec = "__module_private__";
1104     DiagID = diag::ext_warn_duplicate_declspec;
1105     return true;
1106   }
1107 
1108   ModulePrivateLoc = Loc;
1109   return false;
1110 }
1111 
1112 bool DeclSpec::SetConstexprSpec(ConstexprSpecKind ConstexprKind,
1113                                 SourceLocation Loc, const char *&PrevSpec,
1114                                 unsigned &DiagID) {
1115   if (getConstexprSpecifier() != ConstexprSpecKind::Unspecified)
1116     return BadSpecifier(ConstexprKind, getConstexprSpecifier(), PrevSpec,
1117                         DiagID);
1118   ConstexprSpecifier = static_cast<unsigned>(ConstexprKind);
1119   ConstexprLoc = Loc;
1120   return false;
1121 }
1122 
1123 void DeclSpec::SaveWrittenBuiltinSpecs() {
1124   writtenBS.Sign = static_cast<int>(getTypeSpecSign());
1125   writtenBS.Width = static_cast<int>(getTypeSpecWidth());
1126   writtenBS.Type = getTypeSpecType();
1127   // Search the list of attributes for the presence of a mode attribute.
1128   writtenBS.ModeAttr = getAttributes().hasAttribute(ParsedAttr::AT_Mode);
1129 }
1130 
1131 /// Finish - This does final analysis of the declspec, rejecting things like
1132 /// "_Imaginary" (lacking an FP type). After calling this method, DeclSpec is
1133 /// guaranteed to be self-consistent, even if an error occurred.
1134 void DeclSpec::Finish(Sema &S, const PrintingPolicy &Policy) {
1135   // Before possibly changing their values, save specs as written.
1136   SaveWrittenBuiltinSpecs();
1137 
1138   // Check the type specifier components first. No checking for an invalid
1139   // type.
1140   if (TypeSpecType == TST_error)
1141     return;
1142 
1143   // If decltype(auto) is used, no other type specifiers are permitted.
1144   if (TypeSpecType == TST_decltype_auto &&
1145       (getTypeSpecWidth() != TypeSpecifierWidth::Unspecified ||
1146        TypeSpecComplex != TSC_unspecified ||
1147        getTypeSpecSign() != TypeSpecifierSign::Unspecified ||
1148        TypeAltiVecVector || TypeAltiVecPixel || TypeAltiVecBool ||
1149        TypeQualifiers)) {
1150     const unsigned NumLocs = 9;
1151     SourceLocation ExtraLocs[NumLocs] = {
1152         TSWRange.getBegin(), TSCLoc,       TSSLoc,
1153         AltiVecLoc,          TQ_constLoc,  TQ_restrictLoc,
1154         TQ_volatileLoc,      TQ_atomicLoc, TQ_unalignedLoc};
1155     FixItHint Hints[NumLocs];
1156     SourceLocation FirstLoc;
1157     for (unsigned I = 0; I != NumLocs; ++I) {
1158       if (ExtraLocs[I].isValid()) {
1159         if (FirstLoc.isInvalid() ||
1160             S.getSourceManager().isBeforeInTranslationUnit(ExtraLocs[I],
1161                                                            FirstLoc))
1162           FirstLoc = ExtraLocs[I];
1163         Hints[I] = FixItHint::CreateRemoval(ExtraLocs[I]);
1164       }
1165     }
1166     TypeSpecWidth = static_cast<unsigned>(TypeSpecifierWidth::Unspecified);
1167     TypeSpecComplex = TSC_unspecified;
1168     TypeSpecSign = static_cast<unsigned>(TypeSpecifierSign::Unspecified);
1169     TypeAltiVecVector = TypeAltiVecPixel = TypeAltiVecBool = false;
1170     TypeQualifiers = 0;
1171     S.Diag(TSTLoc, diag::err_decltype_auto_cannot_be_combined)
1172       << Hints[0] << Hints[1] << Hints[2] << Hints[3]
1173       << Hints[4] << Hints[5] << Hints[6] << Hints[7];
1174   }
1175 
1176   // Validate and finalize AltiVec vector declspec.
1177   if (TypeAltiVecVector) {
1178     // No vector long long without VSX (or ZVector).
1179     if ((getTypeSpecWidth() == TypeSpecifierWidth::LongLong) &&
1180         !S.Context.getTargetInfo().hasFeature("vsx") &&
1181         !S.getLangOpts().ZVector)
1182       S.Diag(TSWRange.getBegin(), diag::err_invalid_vector_long_long_decl_spec);
1183 
1184     // No vector __int128 prior to Power8.
1185     if ((TypeSpecType == TST_int128) &&
1186         !S.Context.getTargetInfo().hasFeature("power8-vector"))
1187       S.Diag(TSTLoc, diag::err_invalid_vector_int128_decl_spec);
1188 
1189     if (TypeAltiVecBool) {
1190       // Sign specifiers are not allowed with vector bool. (PIM 2.1)
1191       if (getTypeSpecSign() != TypeSpecifierSign::Unspecified) {
1192         S.Diag(TSSLoc, diag::err_invalid_vector_bool_decl_spec)
1193             << getSpecifierName(getTypeSpecSign());
1194       }
1195       // Only char/int are valid with vector bool prior to Power10.
1196       // Power10 adds instructions that produce vector bool data
1197       // for quadwords as well so allow vector bool __int128.
1198       if (((TypeSpecType != TST_unspecified) && (TypeSpecType != TST_char) &&
1199            (TypeSpecType != TST_int) && (TypeSpecType != TST_int128)) ||
1200           TypeAltiVecPixel) {
1201         S.Diag(TSTLoc, diag::err_invalid_vector_bool_decl_spec)
1202           << (TypeAltiVecPixel ? "__pixel" :
1203                                  getSpecifierName((TST)TypeSpecType, Policy));
1204       }
1205       // vector bool __int128 requires Power10.
1206       if ((TypeSpecType == TST_int128) &&
1207           (!S.Context.getTargetInfo().hasFeature("power10-vector")))
1208         S.Diag(TSTLoc, diag::err_invalid_vector_bool_int128_decl_spec);
1209 
1210       // Only 'short' and 'long long' are valid with vector bool. (PIM 2.1)
1211       if ((getTypeSpecWidth() != TypeSpecifierWidth::Unspecified) &&
1212           (getTypeSpecWidth() != TypeSpecifierWidth::Short) &&
1213           (getTypeSpecWidth() != TypeSpecifierWidth::LongLong))
1214         S.Diag(TSWRange.getBegin(), diag::err_invalid_vector_bool_decl_spec)
1215             << getSpecifierName(getTypeSpecWidth());
1216 
1217       // Elements of vector bool are interpreted as unsigned. (PIM 2.1)
1218       if ((TypeSpecType == TST_char) || (TypeSpecType == TST_int) ||
1219           (TypeSpecType == TST_int128) ||
1220           (getTypeSpecWidth() != TypeSpecifierWidth::Unspecified))
1221         TypeSpecSign = static_cast<unsigned>(TypeSpecifierSign::Unsigned);
1222     } else if (TypeSpecType == TST_double) {
1223       // vector long double and vector long long double are never allowed.
1224       // vector double is OK for Power7 and later, and ZVector.
1225       if (getTypeSpecWidth() == TypeSpecifierWidth::Long ||
1226           getTypeSpecWidth() == TypeSpecifierWidth::LongLong)
1227         S.Diag(TSWRange.getBegin(),
1228                diag::err_invalid_vector_long_double_decl_spec);
1229       else if (!S.Context.getTargetInfo().hasFeature("vsx") &&
1230                !S.getLangOpts().ZVector)
1231         S.Diag(TSTLoc, diag::err_invalid_vector_double_decl_spec);
1232     } else if (TypeSpecType == TST_float) {
1233       // vector float is unsupported for ZVector unless we have the
1234       // vector-enhancements facility 1 (ISA revision 12).
1235       if (S.getLangOpts().ZVector &&
1236           !S.Context.getTargetInfo().hasFeature("arch12"))
1237         S.Diag(TSTLoc, diag::err_invalid_vector_float_decl_spec);
1238     } else if (getTypeSpecWidth() == TypeSpecifierWidth::Long) {
1239       // Vector long is unsupported for ZVector, or without VSX, and deprecated
1240       // for AltiVec.
1241       // It has also been historically deprecated on AIX (as an alias for
1242       // "vector int" in both 32-bit and 64-bit modes). It was then made
1243       // unsupported in the Clang-based XL compiler since the deprecated type
1244       // has a number of conflicting semantics and continuing to support it
1245       // is a disservice to users.
1246       if (S.getLangOpts().ZVector ||
1247           !S.Context.getTargetInfo().hasFeature("vsx") ||
1248           S.Context.getTargetInfo().getTriple().isOSAIX())
1249         S.Diag(TSWRange.getBegin(), diag::err_invalid_vector_long_decl_spec);
1250       else
1251         S.Diag(TSWRange.getBegin(),
1252                diag::warn_vector_long_decl_spec_combination)
1253             << getSpecifierName((TST)TypeSpecType, Policy);
1254     }
1255 
1256     if (TypeAltiVecPixel) {
1257       //TODO: perform validation
1258       TypeSpecType = TST_int;
1259       TypeSpecSign = static_cast<unsigned>(TypeSpecifierSign::Unsigned);
1260       TypeSpecWidth = static_cast<unsigned>(TypeSpecifierWidth::Short);
1261       TypeSpecOwned = false;
1262     }
1263   }
1264 
1265   bool IsFixedPointType =
1266       TypeSpecType == TST_accum || TypeSpecType == TST_fract;
1267 
1268   // signed/unsigned are only valid with int/char/wchar_t/_Accum.
1269   if (getTypeSpecSign() != TypeSpecifierSign::Unspecified) {
1270     if (TypeSpecType == TST_unspecified)
1271       TypeSpecType = TST_int; // unsigned -> unsigned int, signed -> signed int.
1272     else if (TypeSpecType != TST_int && TypeSpecType != TST_int128 &&
1273              TypeSpecType != TST_char && TypeSpecType != TST_wchar &&
1274              !IsFixedPointType && TypeSpecType != TST_bitint) {
1275       S.Diag(TSSLoc, diag::err_invalid_sign_spec)
1276         << getSpecifierName((TST)TypeSpecType, Policy);
1277       // signed double -> double.
1278       TypeSpecSign = static_cast<unsigned>(TypeSpecifierSign::Unspecified);
1279     }
1280   }
1281 
1282   // Validate the width of the type.
1283   switch (getTypeSpecWidth()) {
1284   case TypeSpecifierWidth::Unspecified:
1285     break;
1286   case TypeSpecifierWidth::Short:    // short int
1287   case TypeSpecifierWidth::LongLong: // long long int
1288     if (TypeSpecType == TST_unspecified)
1289       TypeSpecType = TST_int; // short -> short int, long long -> long long int.
1290     else if (!(TypeSpecType == TST_int ||
1291                (IsFixedPointType &&
1292                 getTypeSpecWidth() != TypeSpecifierWidth::LongLong))) {
1293       S.Diag(TSWRange.getBegin(), diag::err_invalid_width_spec)
1294           << (int)TypeSpecWidth << getSpecifierName((TST)TypeSpecType, Policy);
1295       TypeSpecType = TST_int;
1296       TypeSpecSat = false;
1297       TypeSpecOwned = false;
1298     }
1299     break;
1300   case TypeSpecifierWidth::Long: // long double, long int
1301     if (TypeSpecType == TST_unspecified)
1302       TypeSpecType = TST_int;  // long -> long int.
1303     else if (TypeSpecType != TST_int && TypeSpecType != TST_double &&
1304              !IsFixedPointType) {
1305       S.Diag(TSWRange.getBegin(), diag::err_invalid_width_spec)
1306           << (int)TypeSpecWidth << getSpecifierName((TST)TypeSpecType, Policy);
1307       TypeSpecType = TST_int;
1308       TypeSpecSat = false;
1309       TypeSpecOwned = false;
1310     }
1311     break;
1312   }
1313 
1314   // TODO: if the implementation does not implement _Complex or _Imaginary,
1315   // disallow their use.  Need information about the backend.
1316   if (TypeSpecComplex != TSC_unspecified) {
1317     if (TypeSpecType == TST_unspecified) {
1318       S.Diag(TSCLoc, diag::ext_plain_complex)
1319         << FixItHint::CreateInsertion(
1320                               S.getLocForEndOfToken(getTypeSpecComplexLoc()),
1321                                                  " double");
1322       TypeSpecType = TST_double;   // _Complex -> _Complex double.
1323     } else if (TypeSpecType == TST_int || TypeSpecType == TST_char ||
1324                TypeSpecType == TST_bitint) {
1325       // Note that this intentionally doesn't include _Complex _Bool.
1326       if (!S.getLangOpts().CPlusPlus)
1327         S.Diag(TSTLoc, diag::ext_integer_complex);
1328     } else if (TypeSpecType != TST_float && TypeSpecType != TST_double &&
1329                TypeSpecType != TST_float128 && TypeSpecType != TST_float16 &&
1330                TypeSpecType != TST_ibm128) {
1331       // FIXME: __fp16?
1332       S.Diag(TSCLoc, diag::err_invalid_complex_spec)
1333         << getSpecifierName((TST)TypeSpecType, Policy);
1334       TypeSpecComplex = TSC_unspecified;
1335     }
1336   }
1337 
1338   // C11 6.7.1/3, C++11 [dcl.stc]p1, GNU TLS: __thread, thread_local and
1339   // _Thread_local can only appear with the 'static' and 'extern' storage class
1340   // specifiers. We also allow __private_extern__ as an extension.
1341   if (ThreadStorageClassSpec != TSCS_unspecified) {
1342     switch (StorageClassSpec) {
1343     case SCS_unspecified:
1344     case SCS_extern:
1345     case SCS_private_extern:
1346     case SCS_static:
1347       break;
1348     default:
1349       if (S.getSourceManager().isBeforeInTranslationUnit(
1350             getThreadStorageClassSpecLoc(), getStorageClassSpecLoc()))
1351         S.Diag(getStorageClassSpecLoc(),
1352              diag::err_invalid_decl_spec_combination)
1353           << DeclSpec::getSpecifierName(getThreadStorageClassSpec())
1354           << SourceRange(getThreadStorageClassSpecLoc());
1355       else
1356         S.Diag(getThreadStorageClassSpecLoc(),
1357              diag::err_invalid_decl_spec_combination)
1358           << DeclSpec::getSpecifierName(getStorageClassSpec())
1359           << SourceRange(getStorageClassSpecLoc());
1360       // Discard the thread storage class specifier to recover.
1361       ThreadStorageClassSpec = TSCS_unspecified;
1362       ThreadStorageClassSpecLoc = SourceLocation();
1363     }
1364   }
1365 
1366   // If no type specifier was provided and we're parsing a language where
1367   // the type specifier is not optional, but we got 'auto' as a storage
1368   // class specifier, then assume this is an attempt to use C++0x's 'auto'
1369   // type specifier.
1370   if (S.getLangOpts().CPlusPlus &&
1371       TypeSpecType == TST_unspecified && StorageClassSpec == SCS_auto) {
1372     TypeSpecType = TST_auto;
1373     StorageClassSpec = SCS_unspecified;
1374     TSTLoc = TSTNameLoc = StorageClassSpecLoc;
1375     StorageClassSpecLoc = SourceLocation();
1376   }
1377   // Diagnose if we've recovered from an ill-formed 'auto' storage class
1378   // specifier in a pre-C++11 dialect of C++ or in a pre-C23 dialect of C.
1379   if (!S.getLangOpts().CPlusPlus11 && !S.getLangOpts().C23 &&
1380       TypeSpecType == TST_auto)
1381     S.Diag(TSTLoc, diag::ext_auto_type_specifier);
1382   if (S.getLangOpts().CPlusPlus && !S.getLangOpts().CPlusPlus11 &&
1383       StorageClassSpec == SCS_auto)
1384     S.Diag(StorageClassSpecLoc, diag::warn_auto_storage_class)
1385       << FixItHint::CreateRemoval(StorageClassSpecLoc);
1386   if (TypeSpecType == TST_char8)
1387     S.Diag(TSTLoc, diag::warn_cxx17_compat_unicode_type);
1388   else if (TypeSpecType == TST_char16 || TypeSpecType == TST_char32)
1389     S.Diag(TSTLoc, diag::warn_cxx98_compat_unicode_type)
1390       << (TypeSpecType == TST_char16 ? "char16_t" : "char32_t");
1391   if (getConstexprSpecifier() == ConstexprSpecKind::Constexpr)
1392     S.Diag(ConstexprLoc, diag::warn_cxx98_compat_constexpr);
1393   else if (getConstexprSpecifier() == ConstexprSpecKind::Consteval)
1394     S.Diag(ConstexprLoc, diag::warn_cxx20_compat_consteval);
1395   else if (getConstexprSpecifier() == ConstexprSpecKind::Constinit)
1396     S.Diag(ConstexprLoc, diag::warn_cxx20_compat_constinit);
1397   // C++ [class.friend]p6:
1398   //   No storage-class-specifier shall appear in the decl-specifier-seq
1399   //   of a friend declaration.
1400   if (isFriendSpecified() &&
1401       (getStorageClassSpec() || getThreadStorageClassSpec())) {
1402     SmallString<32> SpecName;
1403     SourceLocation SCLoc;
1404     FixItHint StorageHint, ThreadHint;
1405 
1406     if (DeclSpec::SCS SC = getStorageClassSpec()) {
1407       SpecName = getSpecifierName(SC);
1408       SCLoc = getStorageClassSpecLoc();
1409       StorageHint = FixItHint::CreateRemoval(SCLoc);
1410     }
1411 
1412     if (DeclSpec::TSCS TSC = getThreadStorageClassSpec()) {
1413       if (!SpecName.empty()) SpecName += " ";
1414       SpecName += getSpecifierName(TSC);
1415       SCLoc = getThreadStorageClassSpecLoc();
1416       ThreadHint = FixItHint::CreateRemoval(SCLoc);
1417     }
1418 
1419     S.Diag(SCLoc, diag::err_friend_decl_spec)
1420       << SpecName << StorageHint << ThreadHint;
1421 
1422     ClearStorageClassSpecs();
1423   }
1424 
1425   // C++11 [dcl.fct.spec]p5:
1426   //   The virtual specifier shall be used only in the initial
1427   //   declaration of a non-static class member function;
1428   // C++11 [dcl.fct.spec]p6:
1429   //   The explicit specifier shall be used only in the declaration of
1430   //   a constructor or conversion function within its class
1431   //   definition;
1432   if (isFriendSpecified() && (isVirtualSpecified() || hasExplicitSpecifier())) {
1433     StringRef Keyword;
1434     FixItHint Hint;
1435     SourceLocation SCLoc;
1436 
1437     if (isVirtualSpecified()) {
1438       Keyword = "virtual";
1439       SCLoc = getVirtualSpecLoc();
1440       Hint = FixItHint::CreateRemoval(SCLoc);
1441     } else {
1442       Keyword = "explicit";
1443       SCLoc = getExplicitSpecLoc();
1444       Hint = FixItHint::CreateRemoval(getExplicitSpecRange());
1445     }
1446 
1447     S.Diag(SCLoc, diag::err_friend_decl_spec)
1448       << Keyword << Hint;
1449 
1450     FS_virtual_specified = false;
1451     FS_explicit_specifier = ExplicitSpecifier();
1452     FS_virtualLoc = FS_explicitLoc = SourceLocation();
1453   }
1454 
1455   assert(!TypeSpecOwned || isDeclRep((TST) TypeSpecType));
1456 
1457   // Okay, now we can infer the real type.
1458 
1459   // TODO: return "auto function" and other bad things based on the real type.
1460 
1461   // 'data definition has no type or storage class'?
1462 }
1463 
1464 bool DeclSpec::isMissingDeclaratorOk() {
1465   TST tst = getTypeSpecType();
1466   return isDeclRep(tst) && getRepAsDecl() != nullptr &&
1467     StorageClassSpec != DeclSpec::SCS_typedef;
1468 }
1469 
1470 void UnqualifiedId::setOperatorFunctionId(SourceLocation OperatorLoc,
1471                                           OverloadedOperatorKind Op,
1472                                           SourceLocation SymbolLocations[3]) {
1473   Kind = UnqualifiedIdKind::IK_OperatorFunctionId;
1474   StartLocation = OperatorLoc;
1475   EndLocation = OperatorLoc;
1476   new (&OperatorFunctionId) struct OFI;
1477   OperatorFunctionId.Operator = Op;
1478   for (unsigned I = 0; I != 3; ++I) {
1479     OperatorFunctionId.SymbolLocations[I] = SymbolLocations[I];
1480 
1481     if (SymbolLocations[I].isValid())
1482       EndLocation = SymbolLocations[I];
1483   }
1484 }
1485 
1486 bool VirtSpecifiers::SetSpecifier(Specifier VS, SourceLocation Loc,
1487                                   const char *&PrevSpec) {
1488   if (!FirstLocation.isValid())
1489     FirstLocation = Loc;
1490   LastLocation = Loc;
1491   LastSpecifier = VS;
1492 
1493   if (Specifiers & VS) {
1494     PrevSpec = getSpecifierName(VS);
1495     return true;
1496   }
1497 
1498   Specifiers |= VS;
1499 
1500   switch (VS) {
1501   default: llvm_unreachable("Unknown specifier!");
1502   case VS_Override: VS_overrideLoc = Loc; break;
1503   case VS_GNU_Final:
1504   case VS_Sealed:
1505   case VS_Final:    VS_finalLoc = Loc; break;
1506   case VS_Abstract: VS_abstractLoc = Loc; break;
1507   }
1508 
1509   return false;
1510 }
1511 
1512 const char *VirtSpecifiers::getSpecifierName(Specifier VS) {
1513   switch (VS) {
1514   default: llvm_unreachable("Unknown specifier");
1515   case VS_Override: return "override";
1516   case VS_Final: return "final";
1517   case VS_GNU_Final: return "__final";
1518   case VS_Sealed: return "sealed";
1519   case VS_Abstract: return "abstract";
1520   }
1521 }
1522