xref: /llvm-project/clang/lib/Sema/DeclSpec.cpp (revision 7eead180b92dcff7eaf9d71df14e33936ec4dbe5) 
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_typeofExpr:
388       if (Expr *E = DS.getRepAsExpr())
389         return E->getType()->isFunctionType();
390       return false;
391 
392 #define TRANSFORM_TYPE_TRAIT_DEF(_, Trait) case TST_##Trait:
393 #include "clang/Basic/TransformTypeTraits.def"
394     case TST_typename:
395     case TST_typeofType: {
396       QualType QT = DS.getRepAsType().get();
397       if (QT.isNull())
398         return false;
399 
400       if (const LocInfoType *LIT = dyn_cast<LocInfoType>(QT))
401         QT = LIT->getType();
402 
403       if (QT.isNull())
404         return false;
405 
406       return QT->isFunctionType();
407     }
408   }
409 
410   llvm_unreachable("Invalid TypeSpecType!");
411 }
412 
413 bool Declarator::isStaticMember() {
414   assert(getContext() == DeclaratorContext::Member);
415   return getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_static ||
416          (getName().getKind() == UnqualifiedIdKind::IK_OperatorFunctionId &&
417           CXXMethodDecl::isStaticOverloadedOperator(
418               getName().OperatorFunctionId.Operator));
419 }
420 
421 bool Declarator::isCtorOrDtor() {
422   return (getName().getKind() == UnqualifiedIdKind::IK_ConstructorName) ||
423          (getName().getKind() == UnqualifiedIdKind::IK_DestructorName);
424 }
425 
426 void DeclSpec::forEachCVRUQualifier(
427     llvm::function_ref<void(TQ, StringRef, SourceLocation)> Handle) {
428   if (TypeQualifiers & TQ_const)
429     Handle(TQ_const, "const", TQ_constLoc);
430   if (TypeQualifiers & TQ_volatile)
431     Handle(TQ_volatile, "volatile", TQ_volatileLoc);
432   if (TypeQualifiers & TQ_restrict)
433     Handle(TQ_restrict, "restrict", TQ_restrictLoc);
434   if (TypeQualifiers & TQ_unaligned)
435     Handle(TQ_unaligned, "unaligned", TQ_unalignedLoc);
436 }
437 
438 void DeclSpec::forEachQualifier(
439     llvm::function_ref<void(TQ, StringRef, SourceLocation)> Handle) {
440   forEachCVRUQualifier(Handle);
441   // FIXME: Add code below to iterate through the attributes and call Handle.
442 }
443 
444 bool DeclSpec::hasTagDefinition() const {
445   if (!TypeSpecOwned)
446     return false;
447   return cast<TagDecl>(getRepAsDecl())->isCompleteDefinition();
448 }
449 
450 /// getParsedSpecifiers - Return a bitmask of which flavors of specifiers this
451 /// declaration specifier includes.
452 ///
453 unsigned DeclSpec::getParsedSpecifiers() const {
454   unsigned Res = 0;
455   if (StorageClassSpec != SCS_unspecified ||
456       ThreadStorageClassSpec != TSCS_unspecified)
457     Res |= PQ_StorageClassSpecifier;
458 
459   if (TypeQualifiers != TQ_unspecified)
460     Res |= PQ_TypeQualifier;
461 
462   if (hasTypeSpecifier())
463     Res |= PQ_TypeSpecifier;
464 
465   if (FS_inline_specified || FS_virtual_specified || hasExplicitSpecifier() ||
466       FS_noreturn_specified || FS_forceinline_specified)
467     Res |= PQ_FunctionSpecifier;
468   return Res;
469 }
470 
471 template <class T> static bool BadSpecifier(T TNew, T TPrev,
472                                             const char *&PrevSpec,
473                                             unsigned &DiagID,
474                                             bool IsExtension = true) {
475   PrevSpec = DeclSpec::getSpecifierName(TPrev);
476   if (TNew != TPrev)
477     DiagID = diag::err_invalid_decl_spec_combination;
478   else
479     DiagID = IsExtension ? diag::ext_warn_duplicate_declspec :
480                            diag::warn_duplicate_declspec;
481   return true;
482 }
483 
484 const char *DeclSpec::getSpecifierName(DeclSpec::SCS S) {
485   switch (S) {
486   case DeclSpec::SCS_unspecified: return "unspecified";
487   case DeclSpec::SCS_typedef:     return "typedef";
488   case DeclSpec::SCS_extern:      return "extern";
489   case DeclSpec::SCS_static:      return "static";
490   case DeclSpec::SCS_auto:        return "auto";
491   case DeclSpec::SCS_register:    return "register";
492   case DeclSpec::SCS_private_extern: return "__private_extern__";
493   case DeclSpec::SCS_mutable:     return "mutable";
494   }
495   llvm_unreachable("Unknown typespec!");
496 }
497 
498 const char *DeclSpec::getSpecifierName(DeclSpec::TSCS S) {
499   switch (S) {
500   case DeclSpec::TSCS_unspecified:   return "unspecified";
501   case DeclSpec::TSCS___thread:      return "__thread";
502   case DeclSpec::TSCS_thread_local:  return "thread_local";
503   case DeclSpec::TSCS__Thread_local: return "_Thread_local";
504   }
505   llvm_unreachable("Unknown typespec!");
506 }
507 
508 const char *DeclSpec::getSpecifierName(TypeSpecifierWidth W) {
509   switch (W) {
510   case TypeSpecifierWidth::Unspecified:
511     return "unspecified";
512   case TypeSpecifierWidth::Short:
513     return "short";
514   case TypeSpecifierWidth::Long:
515     return "long";
516   case TypeSpecifierWidth::LongLong:
517     return "long long";
518   }
519   llvm_unreachable("Unknown typespec!");
520 }
521 
522 const char *DeclSpec::getSpecifierName(TSC C) {
523   switch (C) {
524   case TSC_unspecified: return "unspecified";
525   case TSC_imaginary:   return "imaginary";
526   case TSC_complex:     return "complex";
527   }
528   llvm_unreachable("Unknown typespec!");
529 }
530 
531 const char *DeclSpec::getSpecifierName(TypeSpecifierSign S) {
532   switch (S) {
533   case TypeSpecifierSign::Unspecified:
534     return "unspecified";
535   case TypeSpecifierSign::Signed:
536     return "signed";
537   case TypeSpecifierSign::Unsigned:
538     return "unsigned";
539   }
540   llvm_unreachable("Unknown typespec!");
541 }
542 
543 const char *DeclSpec::getSpecifierName(DeclSpec::TST T,
544                                        const PrintingPolicy &Policy) {
545   switch (T) {
546   case DeclSpec::TST_unspecified: return "unspecified";
547   case DeclSpec::TST_void:        return "void";
548   case DeclSpec::TST_char:        return "char";
549   case DeclSpec::TST_wchar:       return Policy.MSWChar ? "__wchar_t" : "wchar_t";
550   case DeclSpec::TST_char8:       return "char8_t";
551   case DeclSpec::TST_char16:      return "char16_t";
552   case DeclSpec::TST_char32:      return "char32_t";
553   case DeclSpec::TST_int:         return "int";
554   case DeclSpec::TST_int128:      return "__int128";
555   case DeclSpec::TST_bitint:      return "_BitInt";
556   case DeclSpec::TST_half:        return "half";
557   case DeclSpec::TST_float:       return "float";
558   case DeclSpec::TST_double:      return "double";
559   case DeclSpec::TST_accum:       return "_Accum";
560   case DeclSpec::TST_fract:       return "_Fract";
561   case DeclSpec::TST_float16:     return "_Float16";
562   case DeclSpec::TST_float128:    return "__float128";
563   case DeclSpec::TST_ibm128:      return "__ibm128";
564   case DeclSpec::TST_bool:        return Policy.Bool ? "bool" : "_Bool";
565   case DeclSpec::TST_decimal32:   return "_Decimal32";
566   case DeclSpec::TST_decimal64:   return "_Decimal64";
567   case DeclSpec::TST_decimal128:  return "_Decimal128";
568   case DeclSpec::TST_enum:        return "enum";
569   case DeclSpec::TST_class:       return "class";
570   case DeclSpec::TST_union:       return "union";
571   case DeclSpec::TST_struct:      return "struct";
572   case DeclSpec::TST_interface:   return "__interface";
573   case DeclSpec::TST_typename:    return "type-name";
574   case DeclSpec::TST_typeofType:
575   case DeclSpec::TST_typeofExpr:  return "typeof";
576   case DeclSpec::TST_auto:        return "auto";
577   case DeclSpec::TST_auto_type:   return "__auto_type";
578   case DeclSpec::TST_decltype:    return "(decltype)";
579   case DeclSpec::TST_decltype_auto: return "decltype(auto)";
580 #define TRANSFORM_TYPE_TRAIT_DEF(_, Trait)                                     \
581   case DeclSpec::TST_##Trait:                                                  \
582     return "__" #Trait;
583 #include "clang/Basic/TransformTypeTraits.def"
584   case DeclSpec::TST_unknown_anytype: return "__unknown_anytype";
585   case DeclSpec::TST_atomic: return "_Atomic";
586   case DeclSpec::TST_BFloat16: return "__bf16";
587 #define GENERIC_IMAGE_TYPE(ImgType, Id) \
588   case DeclSpec::TST_##ImgType##_t: \
589     return #ImgType "_t";
590 #include "clang/Basic/OpenCLImageTypes.def"
591   case DeclSpec::TST_error:       return "(error)";
592   }
593   llvm_unreachable("Unknown typespec!");
594 }
595 
596 const char *DeclSpec::getSpecifierName(ConstexprSpecKind C) {
597   switch (C) {
598   case ConstexprSpecKind::Unspecified:
599     return "unspecified";
600   case ConstexprSpecKind::Constexpr:
601     return "constexpr";
602   case ConstexprSpecKind::Consteval:
603     return "consteval";
604   case ConstexprSpecKind::Constinit:
605     return "constinit";
606   }
607   llvm_unreachable("Unknown ConstexprSpecKind");
608 }
609 
610 const char *DeclSpec::getSpecifierName(TQ T) {
611   switch (T) {
612   case DeclSpec::TQ_unspecified: return "unspecified";
613   case DeclSpec::TQ_const:       return "const";
614   case DeclSpec::TQ_restrict:    return "restrict";
615   case DeclSpec::TQ_volatile:    return "volatile";
616   case DeclSpec::TQ_atomic:      return "_Atomic";
617   case DeclSpec::TQ_unaligned:   return "__unaligned";
618   }
619   llvm_unreachable("Unknown typespec!");
620 }
621 
622 bool DeclSpec::SetStorageClassSpec(Sema &S, SCS SC, SourceLocation Loc,
623                                    const char *&PrevSpec,
624                                    unsigned &DiagID,
625                                    const PrintingPolicy &Policy) {
626   // OpenCL v1.1 s6.8g: "The extern, static, auto and register storage-class
627   // specifiers are not supported.
628   // It seems sensible to prohibit private_extern too
629   // The cl_clang_storage_class_specifiers extension enables support for
630   // these storage-class specifiers.
631   // OpenCL v1.2 s6.8 changes this to "The auto and register storage-class
632   // specifiers are not supported."
633   if (S.getLangOpts().OpenCL &&
634       !S.getOpenCLOptions().isAvailableOption(
635           "cl_clang_storage_class_specifiers", S.getLangOpts())) {
636     switch (SC) {
637     case SCS_extern:
638     case SCS_private_extern:
639     case SCS_static:
640       if (S.getLangOpts().getOpenCLCompatibleVersion() < 120) {
641         DiagID = diag::err_opencl_unknown_type_specifier;
642         PrevSpec = getSpecifierName(SC);
643         return true;
644       }
645       break;
646     case SCS_auto:
647     case SCS_register:
648       DiagID   = diag::err_opencl_unknown_type_specifier;
649       PrevSpec = getSpecifierName(SC);
650       return true;
651     default:
652       break;
653     }
654   }
655 
656   if (StorageClassSpec != SCS_unspecified) {
657     // Maybe this is an attempt to use C++11 'auto' outside of C++11 mode.
658     bool isInvalid = true;
659     if (TypeSpecType == TST_unspecified && S.getLangOpts().CPlusPlus) {
660       if (SC == SCS_auto)
661         return SetTypeSpecType(TST_auto, Loc, PrevSpec, DiagID, Policy);
662       if (StorageClassSpec == SCS_auto) {
663         isInvalid = SetTypeSpecType(TST_auto, StorageClassSpecLoc,
664                                     PrevSpec, DiagID, Policy);
665         assert(!isInvalid && "auto SCS -> TST recovery failed");
666       }
667     }
668 
669     // Changing storage class is allowed only if the previous one
670     // was the 'extern' that is part of a linkage specification and
671     // the new storage class is 'typedef'.
672     if (isInvalid &&
673         !(SCS_extern_in_linkage_spec &&
674           StorageClassSpec == SCS_extern &&
675           SC == SCS_typedef))
676       return BadSpecifier(SC, (SCS)StorageClassSpec, PrevSpec, DiagID);
677   }
678   StorageClassSpec = SC;
679   StorageClassSpecLoc = Loc;
680   assert((unsigned)SC == StorageClassSpec && "SCS constants overflow bitfield");
681   return false;
682 }
683 
684 bool DeclSpec::SetStorageClassSpecThread(TSCS TSC, SourceLocation Loc,
685                                          const char *&PrevSpec,
686                                          unsigned &DiagID) {
687   if (ThreadStorageClassSpec != TSCS_unspecified)
688     return BadSpecifier(TSC, (TSCS)ThreadStorageClassSpec, PrevSpec, DiagID);
689 
690   ThreadStorageClassSpec = TSC;
691   ThreadStorageClassSpecLoc = Loc;
692   return false;
693 }
694 
695 /// These methods set the specified attribute of the DeclSpec, but return true
696 /// and ignore the request if invalid (e.g. "extern" then "auto" is
697 /// specified).
698 bool DeclSpec::SetTypeSpecWidth(TypeSpecifierWidth W, SourceLocation Loc,
699                                 const char *&PrevSpec, unsigned &DiagID,
700                                 const PrintingPolicy &Policy) {
701   // Overwrite TSWRange.Begin only if TypeSpecWidth was unspecified, so that
702   // for 'long long' we will keep the source location of the first 'long'.
703   if (getTypeSpecWidth() == TypeSpecifierWidth::Unspecified)
704     TSWRange.setBegin(Loc);
705   // Allow turning long -> long long.
706   else if (W != TypeSpecifierWidth::LongLong ||
707            getTypeSpecWidth() != TypeSpecifierWidth::Long)
708     return BadSpecifier(W, getTypeSpecWidth(), PrevSpec, DiagID);
709   TypeSpecWidth = static_cast<unsigned>(W);
710   // Remember location of the last 'long'
711   TSWRange.setEnd(Loc);
712   return false;
713 }
714 
715 bool DeclSpec::SetTypeSpecComplex(TSC C, SourceLocation Loc,
716                                   const char *&PrevSpec,
717                                   unsigned &DiagID) {
718   if (TypeSpecComplex != TSC_unspecified)
719     return BadSpecifier(C, (TSC)TypeSpecComplex, PrevSpec, DiagID);
720   TypeSpecComplex = C;
721   TSCLoc = Loc;
722   return false;
723 }
724 
725 bool DeclSpec::SetTypeSpecSign(TypeSpecifierSign S, SourceLocation Loc,
726                                const char *&PrevSpec, unsigned &DiagID) {
727   if (getTypeSpecSign() != TypeSpecifierSign::Unspecified)
728     return BadSpecifier(S, getTypeSpecSign(), PrevSpec, DiagID);
729   TypeSpecSign = static_cast<unsigned>(S);
730   TSSLoc = Loc;
731   return false;
732 }
733 
734 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
735                                const char *&PrevSpec,
736                                unsigned &DiagID,
737                                ParsedType Rep,
738                                const PrintingPolicy &Policy) {
739   return SetTypeSpecType(T, Loc, Loc, PrevSpec, DiagID, Rep, Policy);
740 }
741 
742 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation TagKwLoc,
743                                SourceLocation TagNameLoc,
744                                const char *&PrevSpec,
745                                unsigned &DiagID,
746                                ParsedType Rep,
747                                const PrintingPolicy &Policy) {
748   assert(isTypeRep(T) && "T does not store a type");
749   assert(Rep && "no type provided!");
750   if (TypeSpecType == TST_error)
751     return false;
752   if (TypeSpecType != TST_unspecified) {
753     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
754     DiagID = diag::err_invalid_decl_spec_combination;
755     return true;
756   }
757   TypeSpecType = T;
758   TypeRep = Rep;
759   TSTLoc = TagKwLoc;
760   TSTNameLoc = TagNameLoc;
761   TypeSpecOwned = false;
762   return false;
763 }
764 
765 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
766                                const char *&PrevSpec,
767                                unsigned &DiagID,
768                                Expr *Rep,
769                                const PrintingPolicy &Policy) {
770   assert(isExprRep(T) && "T does not store an expr");
771   assert(Rep && "no expression provided!");
772   if (TypeSpecType == TST_error)
773     return false;
774   if (TypeSpecType != TST_unspecified) {
775     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
776     DiagID = diag::err_invalid_decl_spec_combination;
777     return true;
778   }
779   TypeSpecType = T;
780   ExprRep = Rep;
781   TSTLoc = Loc;
782   TSTNameLoc = Loc;
783   TypeSpecOwned = false;
784   return false;
785 }
786 
787 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
788                                const char *&PrevSpec,
789                                unsigned &DiagID,
790                                Decl *Rep, bool Owned,
791                                const PrintingPolicy &Policy) {
792   return SetTypeSpecType(T, Loc, Loc, PrevSpec, DiagID, Rep, Owned, Policy);
793 }
794 
795 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation TagKwLoc,
796                                SourceLocation TagNameLoc,
797                                const char *&PrevSpec,
798                                unsigned &DiagID,
799                                Decl *Rep, bool Owned,
800                                const PrintingPolicy &Policy) {
801   assert(isDeclRep(T) && "T does not store a decl");
802   // Unlike the other cases, we don't assert that we actually get a decl.
803 
804   if (TypeSpecType == TST_error)
805     return false;
806   if (TypeSpecType != TST_unspecified) {
807     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
808     DiagID = diag::err_invalid_decl_spec_combination;
809     return true;
810   }
811   TypeSpecType = T;
812   DeclRep = Rep;
813   TSTLoc = TagKwLoc;
814   TSTNameLoc = TagNameLoc;
815   TypeSpecOwned = Owned && Rep != nullptr;
816   return false;
817 }
818 
819 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc, const char *&PrevSpec,
820                                unsigned &DiagID, TemplateIdAnnotation *Rep,
821                                const PrintingPolicy &Policy) {
822   assert(T == TST_auto || T == TST_decltype_auto);
823   ConstrainedAuto = true;
824   TemplateIdRep = Rep;
825   return SetTypeSpecType(T, Loc, PrevSpec, DiagID, Policy);
826 }
827 
828 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
829                                const char *&PrevSpec,
830                                unsigned &DiagID,
831                                const PrintingPolicy &Policy) {
832   assert(!isDeclRep(T) && !isTypeRep(T) && !isExprRep(T) &&
833          "rep required for these type-spec kinds!");
834   if (TypeSpecType == TST_error)
835     return false;
836   if (TypeSpecType != TST_unspecified) {
837     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
838     DiagID = diag::err_invalid_decl_spec_combination;
839     return true;
840   }
841   TSTLoc = Loc;
842   TSTNameLoc = Loc;
843   if (TypeAltiVecVector && (T == TST_bool) && !TypeAltiVecBool) {
844     TypeAltiVecBool = true;
845     return false;
846   }
847   TypeSpecType = T;
848   TypeSpecOwned = false;
849   return false;
850 }
851 
852 bool DeclSpec::SetTypeSpecSat(SourceLocation Loc, const char *&PrevSpec,
853                               unsigned &DiagID) {
854   // Cannot set twice
855   if (TypeSpecSat) {
856     DiagID = diag::warn_duplicate_declspec;
857     PrevSpec = "_Sat";
858     return true;
859   }
860   TypeSpecSat = true;
861   TSSatLoc = Loc;
862   return false;
863 }
864 
865 bool DeclSpec::SetTypeAltiVecVector(bool isAltiVecVector, SourceLocation Loc,
866                           const char *&PrevSpec, unsigned &DiagID,
867                           const PrintingPolicy &Policy) {
868   if (TypeSpecType == TST_error)
869     return false;
870   if (TypeSpecType != TST_unspecified) {
871     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
872     DiagID = diag::err_invalid_vector_decl_spec_combination;
873     return true;
874   }
875   TypeAltiVecVector = isAltiVecVector;
876   AltiVecLoc = Loc;
877   return false;
878 }
879 
880 bool DeclSpec::SetTypePipe(bool isPipe, SourceLocation Loc,
881                            const char *&PrevSpec, unsigned &DiagID,
882                            const PrintingPolicy &Policy) {
883   if (TypeSpecType == TST_error)
884     return false;
885   if (TypeSpecType != TST_unspecified) {
886     PrevSpec = DeclSpec::getSpecifierName((TST)TypeSpecType, Policy);
887     DiagID = diag::err_invalid_decl_spec_combination;
888     return true;
889   }
890 
891   if (isPipe) {
892     TypeSpecPipe = static_cast<unsigned>(TypeSpecifiersPipe::Pipe);
893   }
894   return false;
895 }
896 
897 bool DeclSpec::SetTypeAltiVecPixel(bool isAltiVecPixel, SourceLocation Loc,
898                           const char *&PrevSpec, unsigned &DiagID,
899                           const PrintingPolicy &Policy) {
900   if (TypeSpecType == TST_error)
901     return false;
902   if (!TypeAltiVecVector || TypeAltiVecPixel ||
903       (TypeSpecType != TST_unspecified)) {
904     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
905     DiagID = diag::err_invalid_pixel_decl_spec_combination;
906     return true;
907   }
908   TypeAltiVecPixel = isAltiVecPixel;
909   TSTLoc = Loc;
910   TSTNameLoc = Loc;
911   return false;
912 }
913 
914 bool DeclSpec::SetTypeAltiVecBool(bool isAltiVecBool, SourceLocation Loc,
915                                   const char *&PrevSpec, unsigned &DiagID,
916                                   const PrintingPolicy &Policy) {
917   if (TypeSpecType == TST_error)
918     return false;
919   if (!TypeAltiVecVector || TypeAltiVecBool ||
920       (TypeSpecType != TST_unspecified)) {
921     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
922     DiagID = diag::err_invalid_vector_bool_decl_spec;
923     return true;
924   }
925   TypeAltiVecBool = isAltiVecBool;
926   TSTLoc = Loc;
927   TSTNameLoc = Loc;
928   return false;
929 }
930 
931 bool DeclSpec::SetTypeSpecError() {
932   TypeSpecType = TST_error;
933   TypeSpecOwned = false;
934   TSTLoc = SourceLocation();
935   TSTNameLoc = SourceLocation();
936   return false;
937 }
938 
939 bool DeclSpec::SetBitIntType(SourceLocation KWLoc, Expr *BitsExpr,
940                              const char *&PrevSpec, unsigned &DiagID,
941                              const PrintingPolicy &Policy) {
942   assert(BitsExpr && "no expression provided!");
943   if (TypeSpecType == TST_error)
944     return false;
945 
946   if (TypeSpecType != TST_unspecified) {
947     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
948     DiagID = diag::err_invalid_decl_spec_combination;
949     return true;
950   }
951 
952   TypeSpecType = TST_bitint;
953   ExprRep = BitsExpr;
954   TSTLoc = KWLoc;
955   TSTNameLoc = KWLoc;
956   TypeSpecOwned = false;
957   return false;
958 }
959 
960 bool DeclSpec::SetTypeQual(TQ T, SourceLocation Loc, const char *&PrevSpec,
961                            unsigned &DiagID, const LangOptions &Lang) {
962   // Duplicates are permitted in C99 onwards, but are not permitted in C89 or
963   // C++.  However, since this is likely not what the user intended, we will
964   // always warn.  We do not need to set the qualifier's location since we
965   // already have it.
966   if (TypeQualifiers & T) {
967     bool IsExtension = true;
968     if (Lang.C99)
969       IsExtension = false;
970     return BadSpecifier(T, T, PrevSpec, DiagID, IsExtension);
971   }
972 
973   return SetTypeQual(T, Loc);
974 }
975 
976 bool DeclSpec::SetTypeQual(TQ T, SourceLocation Loc) {
977   TypeQualifiers |= T;
978 
979   switch (T) {
980   case TQ_unspecified: break;
981   case TQ_const:    TQ_constLoc = Loc; return false;
982   case TQ_restrict: TQ_restrictLoc = Loc; return false;
983   case TQ_volatile: TQ_volatileLoc = Loc; return false;
984   case TQ_unaligned: TQ_unalignedLoc = Loc; return false;
985   case TQ_atomic:   TQ_atomicLoc = Loc; return false;
986   }
987 
988   llvm_unreachable("Unknown type qualifier!");
989 }
990 
991 bool DeclSpec::setFunctionSpecInline(SourceLocation Loc, const char *&PrevSpec,
992                                      unsigned &DiagID) {
993   // 'inline inline' is ok.  However, since this is likely not what the user
994   // intended, we will always warn, similar to duplicates of type qualifiers.
995   if (FS_inline_specified) {
996     DiagID = diag::warn_duplicate_declspec;
997     PrevSpec = "inline";
998     return true;
999   }
1000   FS_inline_specified = true;
1001   FS_inlineLoc = Loc;
1002   return false;
1003 }
1004 
1005 bool DeclSpec::setFunctionSpecForceInline(SourceLocation Loc, const char *&PrevSpec,
1006                                           unsigned &DiagID) {
1007   if (FS_forceinline_specified) {
1008     DiagID = diag::warn_duplicate_declspec;
1009     PrevSpec = "__forceinline";
1010     return true;
1011   }
1012   FS_forceinline_specified = true;
1013   FS_forceinlineLoc = Loc;
1014   return false;
1015 }
1016 
1017 bool DeclSpec::setFunctionSpecVirtual(SourceLocation Loc,
1018                                       const char *&PrevSpec,
1019                                       unsigned &DiagID) {
1020   // 'virtual virtual' is ok, but warn as this is likely not what the user
1021   // intended.
1022   if (FS_virtual_specified) {
1023     DiagID = diag::warn_duplicate_declspec;
1024     PrevSpec = "virtual";
1025     return true;
1026   }
1027   FS_virtual_specified = true;
1028   FS_virtualLoc = Loc;
1029   return false;
1030 }
1031 
1032 bool DeclSpec::setFunctionSpecExplicit(SourceLocation Loc,
1033                                        const char *&PrevSpec, unsigned &DiagID,
1034                                        ExplicitSpecifier ExplicitSpec,
1035                                        SourceLocation CloseParenLoc) {
1036   // 'explicit explicit' is ok, but warn as this is likely not what the user
1037   // intended.
1038   if (hasExplicitSpecifier()) {
1039     DiagID = (ExplicitSpec.getExpr() || FS_explicit_specifier.getExpr())
1040                  ? diag::err_duplicate_declspec
1041                  : diag::ext_warn_duplicate_declspec;
1042     PrevSpec = "explicit";
1043     return true;
1044   }
1045   FS_explicit_specifier = ExplicitSpec;
1046   FS_explicitLoc = Loc;
1047   FS_explicitCloseParenLoc = CloseParenLoc;
1048   return false;
1049 }
1050 
1051 bool DeclSpec::setFunctionSpecNoreturn(SourceLocation Loc,
1052                                        const char *&PrevSpec,
1053                                        unsigned &DiagID) {
1054   // '_Noreturn _Noreturn' is ok, but warn as this is likely not what the user
1055   // intended.
1056   if (FS_noreturn_specified) {
1057     DiagID = diag::warn_duplicate_declspec;
1058     PrevSpec = "_Noreturn";
1059     return true;
1060   }
1061   FS_noreturn_specified = true;
1062   FS_noreturnLoc = Loc;
1063   return false;
1064 }
1065 
1066 bool DeclSpec::SetFriendSpec(SourceLocation Loc, const char *&PrevSpec,
1067                              unsigned &DiagID) {
1068   if (Friend_specified) {
1069     PrevSpec = "friend";
1070     // Keep the later location, so that we can later diagnose ill-formed
1071     // declarations like 'friend class X friend;'. Per [class.friend]p3,
1072     // 'friend' must be the first token in a friend declaration that is
1073     // not a function declaration.
1074     FriendLoc = Loc;
1075     DiagID = diag::warn_duplicate_declspec;
1076     return true;
1077   }
1078 
1079   Friend_specified = true;
1080   FriendLoc = Loc;
1081   return false;
1082 }
1083 
1084 bool DeclSpec::setModulePrivateSpec(SourceLocation Loc, const char *&PrevSpec,
1085                                     unsigned &DiagID) {
1086   if (isModulePrivateSpecified()) {
1087     PrevSpec = "__module_private__";
1088     DiagID = diag::ext_warn_duplicate_declspec;
1089     return true;
1090   }
1091 
1092   ModulePrivateLoc = Loc;
1093   return false;
1094 }
1095 
1096 bool DeclSpec::SetConstexprSpec(ConstexprSpecKind ConstexprKind,
1097                                 SourceLocation Loc, const char *&PrevSpec,
1098                                 unsigned &DiagID) {
1099   if (getConstexprSpecifier() != ConstexprSpecKind::Unspecified)
1100     return BadSpecifier(ConstexprKind, getConstexprSpecifier(), PrevSpec,
1101                         DiagID);
1102   ConstexprSpecifier = static_cast<unsigned>(ConstexprKind);
1103   ConstexprLoc = Loc;
1104   return false;
1105 }
1106 
1107 void DeclSpec::SaveWrittenBuiltinSpecs() {
1108   writtenBS.Sign = static_cast<int>(getTypeSpecSign());
1109   writtenBS.Width = static_cast<int>(getTypeSpecWidth());
1110   writtenBS.Type = getTypeSpecType();
1111   // Search the list of attributes for the presence of a mode attribute.
1112   writtenBS.ModeAttr = getAttributes().hasAttribute(ParsedAttr::AT_Mode);
1113 }
1114 
1115 /// Finish - This does final analysis of the declspec, rejecting things like
1116 /// "_Imaginary" (lacking an FP type).  This returns a diagnostic to issue or
1117 /// diag::NUM_DIAGNOSTICS if there is no error.  After calling this method,
1118 /// DeclSpec is guaranteed self-consistent, even if an error occurred.
1119 void DeclSpec::Finish(Sema &S, const PrintingPolicy &Policy) {
1120   // Before possibly changing their values, save specs as written.
1121   SaveWrittenBuiltinSpecs();
1122 
1123   // Check the type specifier components first. No checking for an invalid
1124   // type.
1125   if (TypeSpecType == TST_error)
1126     return;
1127 
1128   // If decltype(auto) is used, no other type specifiers are permitted.
1129   if (TypeSpecType == TST_decltype_auto &&
1130       (getTypeSpecWidth() != TypeSpecifierWidth::Unspecified ||
1131        TypeSpecComplex != TSC_unspecified ||
1132        getTypeSpecSign() != TypeSpecifierSign::Unspecified ||
1133        TypeAltiVecVector || TypeAltiVecPixel || TypeAltiVecBool ||
1134        TypeQualifiers)) {
1135     const unsigned NumLocs = 9;
1136     SourceLocation ExtraLocs[NumLocs] = {
1137         TSWRange.getBegin(), TSCLoc,       TSSLoc,
1138         AltiVecLoc,          TQ_constLoc,  TQ_restrictLoc,
1139         TQ_volatileLoc,      TQ_atomicLoc, TQ_unalignedLoc};
1140     FixItHint Hints[NumLocs];
1141     SourceLocation FirstLoc;
1142     for (unsigned I = 0; I != NumLocs; ++I) {
1143       if (ExtraLocs[I].isValid()) {
1144         if (FirstLoc.isInvalid() ||
1145             S.getSourceManager().isBeforeInTranslationUnit(ExtraLocs[I],
1146                                                            FirstLoc))
1147           FirstLoc = ExtraLocs[I];
1148         Hints[I] = FixItHint::CreateRemoval(ExtraLocs[I]);
1149       }
1150     }
1151     TypeSpecWidth = static_cast<unsigned>(TypeSpecifierWidth::Unspecified);
1152     TypeSpecComplex = TSC_unspecified;
1153     TypeSpecSign = static_cast<unsigned>(TypeSpecifierSign::Unspecified);
1154     TypeAltiVecVector = TypeAltiVecPixel = TypeAltiVecBool = false;
1155     TypeQualifiers = 0;
1156     S.Diag(TSTLoc, diag::err_decltype_auto_cannot_be_combined)
1157       << Hints[0] << Hints[1] << Hints[2] << Hints[3]
1158       << Hints[4] << Hints[5] << Hints[6] << Hints[7];
1159   }
1160 
1161   // Validate and finalize AltiVec vector declspec.
1162   if (TypeAltiVecVector) {
1163     // No vector long long without VSX (or ZVector).
1164     if ((getTypeSpecWidth() == TypeSpecifierWidth::LongLong) &&
1165         !S.Context.getTargetInfo().hasFeature("vsx") &&
1166         !S.getLangOpts().ZVector)
1167       S.Diag(TSWRange.getBegin(), diag::err_invalid_vector_long_long_decl_spec);
1168 
1169     // No vector __int128 prior to Power8.
1170     if ((TypeSpecType == TST_int128) &&
1171         !S.Context.getTargetInfo().hasFeature("power8-vector"))
1172       S.Diag(TSTLoc, diag::err_invalid_vector_int128_decl_spec);
1173 
1174     if (TypeAltiVecBool) {
1175       // Sign specifiers are not allowed with vector bool. (PIM 2.1)
1176       if (getTypeSpecSign() != TypeSpecifierSign::Unspecified) {
1177         S.Diag(TSSLoc, diag::err_invalid_vector_bool_decl_spec)
1178             << getSpecifierName(getTypeSpecSign());
1179       }
1180       // Only char/int are valid with vector bool prior to Power10.
1181       // Power10 adds instructions that produce vector bool data
1182       // for quadwords as well so allow vector bool __int128.
1183       if (((TypeSpecType != TST_unspecified) && (TypeSpecType != TST_char) &&
1184            (TypeSpecType != TST_int) && (TypeSpecType != TST_int128)) ||
1185           TypeAltiVecPixel) {
1186         S.Diag(TSTLoc, diag::err_invalid_vector_bool_decl_spec)
1187           << (TypeAltiVecPixel ? "__pixel" :
1188                                  getSpecifierName((TST)TypeSpecType, Policy));
1189       }
1190       // vector bool __int128 requires Power10.
1191       if ((TypeSpecType == TST_int128) &&
1192           (!S.Context.getTargetInfo().hasFeature("power10-vector")))
1193         S.Diag(TSTLoc, diag::err_invalid_vector_bool_int128_decl_spec);
1194 
1195       // Only 'short' and 'long long' are valid with vector bool. (PIM 2.1)
1196       if ((getTypeSpecWidth() != TypeSpecifierWidth::Unspecified) &&
1197           (getTypeSpecWidth() != TypeSpecifierWidth::Short) &&
1198           (getTypeSpecWidth() != TypeSpecifierWidth::LongLong))
1199         S.Diag(TSWRange.getBegin(), diag::err_invalid_vector_bool_decl_spec)
1200             << getSpecifierName(getTypeSpecWidth());
1201 
1202       // Elements of vector bool are interpreted as unsigned. (PIM 2.1)
1203       if ((TypeSpecType == TST_char) || (TypeSpecType == TST_int) ||
1204           (TypeSpecType == TST_int128) ||
1205           (getTypeSpecWidth() != TypeSpecifierWidth::Unspecified))
1206         TypeSpecSign = static_cast<unsigned>(TypeSpecifierSign::Unsigned);
1207     } else if (TypeSpecType == TST_double) {
1208       // vector long double and vector long long double are never allowed.
1209       // vector double is OK for Power7 and later, and ZVector.
1210       if (getTypeSpecWidth() == TypeSpecifierWidth::Long ||
1211           getTypeSpecWidth() == TypeSpecifierWidth::LongLong)
1212         S.Diag(TSWRange.getBegin(),
1213                diag::err_invalid_vector_long_double_decl_spec);
1214       else if (!S.Context.getTargetInfo().hasFeature("vsx") &&
1215                !S.getLangOpts().ZVector)
1216         S.Diag(TSTLoc, diag::err_invalid_vector_double_decl_spec);
1217     } else if (TypeSpecType == TST_float) {
1218       // vector float is unsupported for ZVector unless we have the
1219       // vector-enhancements facility 1 (ISA revision 12).
1220       if (S.getLangOpts().ZVector &&
1221           !S.Context.getTargetInfo().hasFeature("arch12"))
1222         S.Diag(TSTLoc, diag::err_invalid_vector_float_decl_spec);
1223     } else if (getTypeSpecWidth() == TypeSpecifierWidth::Long) {
1224       // Vector long is unsupported for ZVector, or without VSX, and deprecated
1225       // for AltiVec.
1226       // It has also been historically deprecated on AIX (as an alias for
1227       // "vector int" in both 32-bit and 64-bit modes). It was then made
1228       // unsupported in the Clang-based XL compiler since the deprecated type
1229       // has a number of conflicting semantics and continuing to support it
1230       // is a disservice to users.
1231       if (S.getLangOpts().ZVector ||
1232           !S.Context.getTargetInfo().hasFeature("vsx") ||
1233           S.Context.getTargetInfo().getTriple().isOSAIX())
1234         S.Diag(TSWRange.getBegin(), diag::err_invalid_vector_long_decl_spec);
1235       else
1236         S.Diag(TSWRange.getBegin(),
1237                diag::warn_vector_long_decl_spec_combination)
1238             << getSpecifierName((TST)TypeSpecType, Policy);
1239     }
1240 
1241     if (TypeAltiVecPixel) {
1242       //TODO: perform validation
1243       TypeSpecType = TST_int;
1244       TypeSpecSign = static_cast<unsigned>(TypeSpecifierSign::Unsigned);
1245       TypeSpecWidth = static_cast<unsigned>(TypeSpecifierWidth::Short);
1246       TypeSpecOwned = false;
1247     }
1248   }
1249 
1250   bool IsFixedPointType =
1251       TypeSpecType == TST_accum || TypeSpecType == TST_fract;
1252 
1253   // signed/unsigned are only valid with int/char/wchar_t/_Accum.
1254   if (getTypeSpecSign() != TypeSpecifierSign::Unspecified) {
1255     if (TypeSpecType == TST_unspecified)
1256       TypeSpecType = TST_int; // unsigned -> unsigned int, signed -> signed int.
1257     else if (TypeSpecType != TST_int && TypeSpecType != TST_int128 &&
1258              TypeSpecType != TST_char && TypeSpecType != TST_wchar &&
1259              !IsFixedPointType && TypeSpecType != TST_bitint) {
1260       S.Diag(TSSLoc, diag::err_invalid_sign_spec)
1261         << getSpecifierName((TST)TypeSpecType, Policy);
1262       // signed double -> double.
1263       TypeSpecSign = static_cast<unsigned>(TypeSpecifierSign::Unspecified);
1264     }
1265   }
1266 
1267   // Validate the width of the type.
1268   switch (getTypeSpecWidth()) {
1269   case TypeSpecifierWidth::Unspecified:
1270     break;
1271   case TypeSpecifierWidth::Short:    // short int
1272   case TypeSpecifierWidth::LongLong: // long long int
1273     if (TypeSpecType == TST_unspecified)
1274       TypeSpecType = TST_int; // short -> short int, long long -> long long int.
1275     else if (!(TypeSpecType == TST_int ||
1276                (IsFixedPointType &&
1277                 getTypeSpecWidth() != TypeSpecifierWidth::LongLong))) {
1278       S.Diag(TSWRange.getBegin(), diag::err_invalid_width_spec)
1279           << (int)TypeSpecWidth << getSpecifierName((TST)TypeSpecType, Policy);
1280       TypeSpecType = TST_int;
1281       TypeSpecSat = false;
1282       TypeSpecOwned = false;
1283     }
1284     break;
1285   case TypeSpecifierWidth::Long: // long double, long int
1286     if (TypeSpecType == TST_unspecified)
1287       TypeSpecType = TST_int;  // long -> long int.
1288     else if (TypeSpecType != TST_int && TypeSpecType != TST_double &&
1289              !IsFixedPointType) {
1290       S.Diag(TSWRange.getBegin(), diag::err_invalid_width_spec)
1291           << (int)TypeSpecWidth << getSpecifierName((TST)TypeSpecType, Policy);
1292       TypeSpecType = TST_int;
1293       TypeSpecSat = false;
1294       TypeSpecOwned = false;
1295     }
1296     break;
1297   }
1298 
1299   // TODO: if the implementation does not implement _Complex or _Imaginary,
1300   // disallow their use.  Need information about the backend.
1301   if (TypeSpecComplex != TSC_unspecified) {
1302     if (TypeSpecType == TST_unspecified) {
1303       S.Diag(TSCLoc, diag::ext_plain_complex)
1304         << FixItHint::CreateInsertion(
1305                               S.getLocForEndOfToken(getTypeSpecComplexLoc()),
1306                                                  " double");
1307       TypeSpecType = TST_double;   // _Complex -> _Complex double.
1308     } else if (TypeSpecType == TST_int || TypeSpecType == TST_char ||
1309                TypeSpecType == TST_bitint) {
1310       // Note that this intentionally doesn't include _Complex _Bool.
1311       if (!S.getLangOpts().CPlusPlus)
1312         S.Diag(TSTLoc, diag::ext_integer_complex);
1313     } else if (TypeSpecType != TST_float && TypeSpecType != TST_double &&
1314                TypeSpecType != TST_float128 && TypeSpecType != TST_float16 &&
1315                TypeSpecType != TST_ibm128) {
1316       // FIXME: __fp16?
1317       S.Diag(TSCLoc, diag::err_invalid_complex_spec)
1318         << getSpecifierName((TST)TypeSpecType, Policy);
1319       TypeSpecComplex = TSC_unspecified;
1320     }
1321   }
1322 
1323   // C11 6.7.1/3, C++11 [dcl.stc]p1, GNU TLS: __thread, thread_local and
1324   // _Thread_local can only appear with the 'static' and 'extern' storage class
1325   // specifiers. We also allow __private_extern__ as an extension.
1326   if (ThreadStorageClassSpec != TSCS_unspecified) {
1327     switch (StorageClassSpec) {
1328     case SCS_unspecified:
1329     case SCS_extern:
1330     case SCS_private_extern:
1331     case SCS_static:
1332       break;
1333     default:
1334       if (S.getSourceManager().isBeforeInTranslationUnit(
1335             getThreadStorageClassSpecLoc(), getStorageClassSpecLoc()))
1336         S.Diag(getStorageClassSpecLoc(),
1337              diag::err_invalid_decl_spec_combination)
1338           << DeclSpec::getSpecifierName(getThreadStorageClassSpec())
1339           << SourceRange(getThreadStorageClassSpecLoc());
1340       else
1341         S.Diag(getThreadStorageClassSpecLoc(),
1342              diag::err_invalid_decl_spec_combination)
1343           << DeclSpec::getSpecifierName(getStorageClassSpec())
1344           << SourceRange(getStorageClassSpecLoc());
1345       // Discard the thread storage class specifier to recover.
1346       ThreadStorageClassSpec = TSCS_unspecified;
1347       ThreadStorageClassSpecLoc = SourceLocation();
1348     }
1349   }
1350 
1351   // If no type specifier was provided and we're parsing a language where
1352   // the type specifier is not optional, but we got 'auto' as a storage
1353   // class specifier, then assume this is an attempt to use C++0x's 'auto'
1354   // type specifier.
1355   if (S.getLangOpts().CPlusPlus &&
1356       TypeSpecType == TST_unspecified && StorageClassSpec == SCS_auto) {
1357     TypeSpecType = TST_auto;
1358     StorageClassSpec = SCS_unspecified;
1359     TSTLoc = TSTNameLoc = StorageClassSpecLoc;
1360     StorageClassSpecLoc = SourceLocation();
1361   }
1362   // Diagnose if we've recovered from an ill-formed 'auto' storage class
1363   // specifier in a pre-C++11 dialect of C++.
1364   if (!S.getLangOpts().CPlusPlus11 && TypeSpecType == TST_auto)
1365     S.Diag(TSTLoc, diag::ext_auto_type_specifier);
1366   if (S.getLangOpts().CPlusPlus && !S.getLangOpts().CPlusPlus11 &&
1367       StorageClassSpec == SCS_auto)
1368     S.Diag(StorageClassSpecLoc, diag::warn_auto_storage_class)
1369       << FixItHint::CreateRemoval(StorageClassSpecLoc);
1370   if (TypeSpecType == TST_char8)
1371     S.Diag(TSTLoc, diag::warn_cxx17_compat_unicode_type);
1372   else if (TypeSpecType == TST_char16 || TypeSpecType == TST_char32)
1373     S.Diag(TSTLoc, diag::warn_cxx98_compat_unicode_type)
1374       << (TypeSpecType == TST_char16 ? "char16_t" : "char32_t");
1375   if (getConstexprSpecifier() == ConstexprSpecKind::Constexpr)
1376     S.Diag(ConstexprLoc, diag::warn_cxx98_compat_constexpr);
1377   else if (getConstexprSpecifier() == ConstexprSpecKind::Consteval)
1378     S.Diag(ConstexprLoc, diag::warn_cxx20_compat_consteval);
1379   else if (getConstexprSpecifier() == ConstexprSpecKind::Constinit)
1380     S.Diag(ConstexprLoc, diag::warn_cxx20_compat_constinit);
1381   // C++ [class.friend]p6:
1382   //   No storage-class-specifier shall appear in the decl-specifier-seq
1383   //   of a friend declaration.
1384   if (isFriendSpecified() &&
1385       (getStorageClassSpec() || getThreadStorageClassSpec())) {
1386     SmallString<32> SpecName;
1387     SourceLocation SCLoc;
1388     FixItHint StorageHint, ThreadHint;
1389 
1390     if (DeclSpec::SCS SC = getStorageClassSpec()) {
1391       SpecName = getSpecifierName(SC);
1392       SCLoc = getStorageClassSpecLoc();
1393       StorageHint = FixItHint::CreateRemoval(SCLoc);
1394     }
1395 
1396     if (DeclSpec::TSCS TSC = getThreadStorageClassSpec()) {
1397       if (!SpecName.empty()) SpecName += " ";
1398       SpecName += getSpecifierName(TSC);
1399       SCLoc = getThreadStorageClassSpecLoc();
1400       ThreadHint = FixItHint::CreateRemoval(SCLoc);
1401     }
1402 
1403     S.Diag(SCLoc, diag::err_friend_decl_spec)
1404       << SpecName << StorageHint << ThreadHint;
1405 
1406     ClearStorageClassSpecs();
1407   }
1408 
1409   // C++11 [dcl.fct.spec]p5:
1410   //   The virtual specifier shall be used only in the initial
1411   //   declaration of a non-static class member function;
1412   // C++11 [dcl.fct.spec]p6:
1413   //   The explicit specifier shall be used only in the declaration of
1414   //   a constructor or conversion function within its class
1415   //   definition;
1416   if (isFriendSpecified() && (isVirtualSpecified() || hasExplicitSpecifier())) {
1417     StringRef Keyword;
1418     FixItHint Hint;
1419     SourceLocation SCLoc;
1420 
1421     if (isVirtualSpecified()) {
1422       Keyword = "virtual";
1423       SCLoc = getVirtualSpecLoc();
1424       Hint = FixItHint::CreateRemoval(SCLoc);
1425     } else {
1426       Keyword = "explicit";
1427       SCLoc = getExplicitSpecLoc();
1428       Hint = FixItHint::CreateRemoval(getExplicitSpecRange());
1429     }
1430 
1431     S.Diag(SCLoc, diag::err_friend_decl_spec)
1432       << Keyword << Hint;
1433 
1434     FS_virtual_specified = false;
1435     FS_explicit_specifier = ExplicitSpecifier();
1436     FS_virtualLoc = FS_explicitLoc = SourceLocation();
1437   }
1438 
1439   assert(!TypeSpecOwned || isDeclRep((TST) TypeSpecType));
1440 
1441   // Okay, now we can infer the real type.
1442 
1443   // TODO: return "auto function" and other bad things based on the real type.
1444 
1445   // 'data definition has no type or storage class'?
1446 }
1447 
1448 bool DeclSpec::isMissingDeclaratorOk() {
1449   TST tst = getTypeSpecType();
1450   return isDeclRep(tst) && getRepAsDecl() != nullptr &&
1451     StorageClassSpec != DeclSpec::SCS_typedef;
1452 }
1453 
1454 void UnqualifiedId::setOperatorFunctionId(SourceLocation OperatorLoc,
1455                                           OverloadedOperatorKind Op,
1456                                           SourceLocation SymbolLocations[3]) {
1457   Kind = UnqualifiedIdKind::IK_OperatorFunctionId;
1458   StartLocation = OperatorLoc;
1459   EndLocation = OperatorLoc;
1460   new (&OperatorFunctionId) struct OFI;
1461   OperatorFunctionId.Operator = Op;
1462   for (unsigned I = 0; I != 3; ++I) {
1463     OperatorFunctionId.SymbolLocations[I] = SymbolLocations[I];
1464 
1465     if (SymbolLocations[I].isValid())
1466       EndLocation = SymbolLocations[I];
1467   }
1468 }
1469 
1470 bool VirtSpecifiers::SetSpecifier(Specifier VS, SourceLocation Loc,
1471                                   const char *&PrevSpec) {
1472   if (!FirstLocation.isValid())
1473     FirstLocation = Loc;
1474   LastLocation = Loc;
1475   LastSpecifier = VS;
1476 
1477   if (Specifiers & VS) {
1478     PrevSpec = getSpecifierName(VS);
1479     return true;
1480   }
1481 
1482   Specifiers |= VS;
1483 
1484   switch (VS) {
1485   default: llvm_unreachable("Unknown specifier!");
1486   case VS_Override: VS_overrideLoc = Loc; break;
1487   case VS_GNU_Final:
1488   case VS_Sealed:
1489   case VS_Final:    VS_finalLoc = Loc; break;
1490   case VS_Abstract: VS_abstractLoc = Loc; break;
1491   }
1492 
1493   return false;
1494 }
1495 
1496 const char *VirtSpecifiers::getSpecifierName(Specifier VS) {
1497   switch (VS) {
1498   default: llvm_unreachable("Unknown specifier");
1499   case VS_Override: return "override";
1500   case VS_Final: return "final";
1501   case VS_GNU_Final: return "__final";
1502   case VS_Sealed: return "sealed";
1503   case VS_Abstract: return "abstract";
1504   }
1505 }
1506