xref: /freebsd/contrib/llvm-project/clang/lib/Sema/DeclSpec.cpp (revision 13ec1e3155c7e9bf037b12af186351b7fa9b9450) 
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/TargetInfo.h"
22 #include "clang/Sema/ParsedTemplate.h"
23 #include "clang/Sema/Sema.h"
24 #include "clang/Sema/SemaDiagnostic.h"
25 #include "llvm/ADT/STLExtras.h"
26 #include "llvm/ADT/SmallString.h"
27 #include <cstring>
28 using namespace clang;
29 
30 
31 void UnqualifiedId::setTemplateId(TemplateIdAnnotation *TemplateId) {
32   assert(TemplateId && "NULL template-id annotation?");
33   assert(!TemplateId->isInvalid() &&
34          "should not convert invalid template-ids to unqualified-ids");
35 
36   Kind = UnqualifiedIdKind::IK_TemplateId;
37   this->TemplateId = TemplateId;
38   StartLocation = TemplateId->TemplateNameLoc;
39   EndLocation = TemplateId->RAngleLoc;
40 }
41 
42 void UnqualifiedId::setConstructorTemplateId(TemplateIdAnnotation *TemplateId) {
43   assert(TemplateId && "NULL template-id annotation?");
44   assert(!TemplateId->isInvalid() &&
45          "should not convert invalid template-ids to unqualified-ids");
46 
47   Kind = UnqualifiedIdKind::IK_ConstructorTemplateId;
48   this->TemplateId = TemplateId;
49   StartLocation = TemplateId->TemplateNameLoc;
50   EndLocation = TemplateId->RAngleLoc;
51 }
52 
53 void CXXScopeSpec::Extend(ASTContext &Context, SourceLocation TemplateKWLoc,
54                           TypeLoc TL, SourceLocation ColonColonLoc) {
55   Builder.Extend(Context, TemplateKWLoc, TL, ColonColonLoc);
56   if (Range.getBegin().isInvalid())
57     Range.setBegin(TL.getBeginLoc());
58   Range.setEnd(ColonColonLoc);
59 
60   assert(Range == Builder.getSourceRange() &&
61          "NestedNameSpecifierLoc range computation incorrect");
62 }
63 
64 void CXXScopeSpec::Extend(ASTContext &Context, IdentifierInfo *Identifier,
65                           SourceLocation IdentifierLoc,
66                           SourceLocation ColonColonLoc) {
67   Builder.Extend(Context, Identifier, IdentifierLoc, ColonColonLoc);
68 
69   if (Range.getBegin().isInvalid())
70     Range.setBegin(IdentifierLoc);
71   Range.setEnd(ColonColonLoc);
72 
73   assert(Range == Builder.getSourceRange() &&
74          "NestedNameSpecifierLoc range computation incorrect");
75 }
76 
77 void CXXScopeSpec::Extend(ASTContext &Context, NamespaceDecl *Namespace,
78                           SourceLocation NamespaceLoc,
79                           SourceLocation ColonColonLoc) {
80   Builder.Extend(Context, Namespace, NamespaceLoc, ColonColonLoc);
81 
82   if (Range.getBegin().isInvalid())
83     Range.setBegin(NamespaceLoc);
84   Range.setEnd(ColonColonLoc);
85 
86   assert(Range == Builder.getSourceRange() &&
87          "NestedNameSpecifierLoc range computation incorrect");
88 }
89 
90 void CXXScopeSpec::Extend(ASTContext &Context, NamespaceAliasDecl *Alias,
91                           SourceLocation AliasLoc,
92                           SourceLocation ColonColonLoc) {
93   Builder.Extend(Context, Alias, AliasLoc, ColonColonLoc);
94 
95   if (Range.getBegin().isInvalid())
96     Range.setBegin(AliasLoc);
97   Range.setEnd(ColonColonLoc);
98 
99   assert(Range == Builder.getSourceRange() &&
100          "NestedNameSpecifierLoc range computation incorrect");
101 }
102 
103 void CXXScopeSpec::MakeGlobal(ASTContext &Context,
104                               SourceLocation ColonColonLoc) {
105   Builder.MakeGlobal(Context, ColonColonLoc);
106 
107   Range = SourceRange(ColonColonLoc);
108 
109   assert(Range == Builder.getSourceRange() &&
110          "NestedNameSpecifierLoc range computation incorrect");
111 }
112 
113 void CXXScopeSpec::MakeSuper(ASTContext &Context, CXXRecordDecl *RD,
114                              SourceLocation SuperLoc,
115                              SourceLocation ColonColonLoc) {
116   Builder.MakeSuper(Context, RD, SuperLoc, ColonColonLoc);
117 
118   Range.setBegin(SuperLoc);
119   Range.setEnd(ColonColonLoc);
120 
121   assert(Range == Builder.getSourceRange() &&
122   "NestedNameSpecifierLoc range computation incorrect");
123 }
124 
125 void CXXScopeSpec::MakeTrivial(ASTContext &Context,
126                                NestedNameSpecifier *Qualifier, SourceRange R) {
127   Builder.MakeTrivial(Context, Qualifier, R);
128   Range = R;
129 }
130 
131 void CXXScopeSpec::Adopt(NestedNameSpecifierLoc Other) {
132   if (!Other) {
133     Range = SourceRange();
134     Builder.Clear();
135     return;
136   }
137 
138   Range = Other.getSourceRange();
139   Builder.Adopt(Other);
140   assert(Range == Builder.getSourceRange() &&
141          "NestedNameSpecifierLoc range computation incorrect");
142 }
143 
144 SourceLocation CXXScopeSpec::getLastQualifierNameLoc() const {
145   if (!Builder.getRepresentation())
146     return SourceLocation();
147   return Builder.getTemporary().getLocalBeginLoc();
148 }
149 
150 NestedNameSpecifierLoc
151 CXXScopeSpec::getWithLocInContext(ASTContext &Context) const {
152   if (!Builder.getRepresentation())
153     return NestedNameSpecifierLoc();
154 
155   return Builder.getWithLocInContext(Context);
156 }
157 
158 /// DeclaratorChunk::getFunction - Return a DeclaratorChunk for a function.
159 /// "TheDeclarator" is the declarator that this will be added to.
160 DeclaratorChunk DeclaratorChunk::getFunction(bool hasProto,
161                                              bool isAmbiguous,
162                                              SourceLocation LParenLoc,
163                                              ParamInfo *Params,
164                                              unsigned NumParams,
165                                              SourceLocation EllipsisLoc,
166                                              SourceLocation RParenLoc,
167                                              bool RefQualifierIsLvalueRef,
168                                              SourceLocation RefQualifierLoc,
169                                              SourceLocation MutableLoc,
170                                              ExceptionSpecificationType
171                                                  ESpecType,
172                                              SourceRange ESpecRange,
173                                              ParsedType *Exceptions,
174                                              SourceRange *ExceptionRanges,
175                                              unsigned NumExceptions,
176                                              Expr *NoexceptExpr,
177                                              CachedTokens *ExceptionSpecTokens,
178                                              ArrayRef<NamedDecl*>
179                                                  DeclsInPrototype,
180                                              SourceLocation LocalRangeBegin,
181                                              SourceLocation LocalRangeEnd,
182                                              Declarator &TheDeclarator,
183                                              TypeResult TrailingReturnType,
184                                              SourceLocation
185                                                  TrailingReturnTypeLoc,
186                                              DeclSpec *MethodQualifiers) {
187   assert(!(MethodQualifiers && MethodQualifiers->getTypeQualifiers() & DeclSpec::TQ_atomic) &&
188          "function cannot have _Atomic qualifier");
189 
190   DeclaratorChunk I;
191   I.Kind                        = Function;
192   I.Loc                         = LocalRangeBegin;
193   I.EndLoc                      = LocalRangeEnd;
194   new (&I.Fun) FunctionTypeInfo;
195   I.Fun.hasPrototype            = hasProto;
196   I.Fun.isVariadic              = EllipsisLoc.isValid();
197   I.Fun.isAmbiguous             = isAmbiguous;
198   I.Fun.LParenLoc               = LParenLoc;
199   I.Fun.EllipsisLoc             = EllipsisLoc;
200   I.Fun.RParenLoc               = RParenLoc;
201   I.Fun.DeleteParams            = false;
202   I.Fun.NumParams               = NumParams;
203   I.Fun.Params                  = nullptr;
204   I.Fun.RefQualifierIsLValueRef = RefQualifierIsLvalueRef;
205   I.Fun.RefQualifierLoc         = RefQualifierLoc;
206   I.Fun.MutableLoc              = MutableLoc;
207   I.Fun.ExceptionSpecType       = ESpecType;
208   I.Fun.ExceptionSpecLocBeg     = ESpecRange.getBegin();
209   I.Fun.ExceptionSpecLocEnd     = ESpecRange.getEnd();
210   I.Fun.NumExceptionsOrDecls    = 0;
211   I.Fun.Exceptions              = nullptr;
212   I.Fun.NoexceptExpr            = nullptr;
213   I.Fun.HasTrailingReturnType   = TrailingReturnType.isUsable() ||
214                                   TrailingReturnType.isInvalid();
215   I.Fun.TrailingReturnType      = TrailingReturnType.get();
216   I.Fun.TrailingReturnTypeLoc   = TrailingReturnTypeLoc;
217   I.Fun.MethodQualifiers        = nullptr;
218   I.Fun.QualAttrFactory         = nullptr;
219 
220   if (MethodQualifiers && (MethodQualifiers->getTypeQualifiers() ||
221                            MethodQualifiers->getAttributes().size())) {
222     auto &attrs = MethodQualifiers->getAttributes();
223     I.Fun.MethodQualifiers = new DeclSpec(attrs.getPool().getFactory());
224     MethodQualifiers->forEachCVRUQualifier(
225         [&](DeclSpec::TQ TypeQual, StringRef PrintName, SourceLocation SL) {
226           I.Fun.MethodQualifiers->SetTypeQual(TypeQual, SL);
227         });
228     I.Fun.MethodQualifiers->getAttributes().takeAllFrom(attrs);
229     I.Fun.MethodQualifiers->getAttributePool().takeAllFrom(attrs.getPool());
230   }
231 
232   assert(I.Fun.ExceptionSpecType == ESpecType && "bitfield overflow");
233 
234   // new[] a parameter array if needed.
235   if (NumParams) {
236     // If the 'InlineParams' in Declarator is unused and big enough, put our
237     // parameter list there (in an effort to avoid new/delete traffic).  If it
238     // is already used (consider a function returning a function pointer) or too
239     // small (function with too many parameters), go to the heap.
240     if (!TheDeclarator.InlineStorageUsed &&
241         NumParams <= llvm::array_lengthof(TheDeclarator.InlineParams)) {
242       I.Fun.Params = TheDeclarator.InlineParams;
243       new (I.Fun.Params) ParamInfo[NumParams];
244       I.Fun.DeleteParams = false;
245       TheDeclarator.InlineStorageUsed = true;
246     } else {
247       I.Fun.Params = new DeclaratorChunk::ParamInfo[NumParams];
248       I.Fun.DeleteParams = true;
249     }
250     for (unsigned i = 0; i < NumParams; i++)
251       I.Fun.Params[i] = std::move(Params[i]);
252   }
253 
254   // Check what exception specification information we should actually store.
255   switch (ESpecType) {
256   default: break; // By default, save nothing.
257   case EST_Dynamic:
258     // new[] an exception array if needed
259     if (NumExceptions) {
260       I.Fun.NumExceptionsOrDecls = NumExceptions;
261       I.Fun.Exceptions = new DeclaratorChunk::TypeAndRange[NumExceptions];
262       for (unsigned i = 0; i != NumExceptions; ++i) {
263         I.Fun.Exceptions[i].Ty = Exceptions[i];
264         I.Fun.Exceptions[i].Range = ExceptionRanges[i];
265       }
266     }
267     break;
268 
269   case EST_DependentNoexcept:
270   case EST_NoexceptFalse:
271   case EST_NoexceptTrue:
272     I.Fun.NoexceptExpr = NoexceptExpr;
273     break;
274 
275   case EST_Unparsed:
276     I.Fun.ExceptionSpecTokens = ExceptionSpecTokens;
277     break;
278   }
279 
280   if (!DeclsInPrototype.empty()) {
281     assert(ESpecType == EST_None && NumExceptions == 0 &&
282            "cannot have exception specifiers and decls in prototype");
283     I.Fun.NumExceptionsOrDecls = DeclsInPrototype.size();
284     // Copy the array of decls into stable heap storage.
285     I.Fun.DeclsInPrototype = new NamedDecl *[DeclsInPrototype.size()];
286     for (size_t J = 0; J < DeclsInPrototype.size(); ++J)
287       I.Fun.DeclsInPrototype[J] = DeclsInPrototype[J];
288   }
289 
290   return I;
291 }
292 
293 void Declarator::setDecompositionBindings(
294     SourceLocation LSquareLoc,
295     ArrayRef<DecompositionDeclarator::Binding> Bindings,
296     SourceLocation RSquareLoc) {
297   assert(!hasName() && "declarator given multiple names!");
298 
299   BindingGroup.LSquareLoc = LSquareLoc;
300   BindingGroup.RSquareLoc = RSquareLoc;
301   BindingGroup.NumBindings = Bindings.size();
302   Range.setEnd(RSquareLoc);
303 
304   // We're now past the identifier.
305   SetIdentifier(nullptr, LSquareLoc);
306   Name.EndLocation = RSquareLoc;
307 
308   // Allocate storage for bindings and stash them away.
309   if (Bindings.size()) {
310     if (!InlineStorageUsed &&
311         Bindings.size() <= llvm::array_lengthof(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_enum:
362     case TST_error:
363     case TST_float:
364     case TST_half:
365     case TST_int:
366     case TST_int128:
367     case TST_extint:
368     case TST_struct:
369     case TST_interface:
370     case TST_union:
371     case TST_unknown_anytype:
372     case TST_unspecified:
373     case TST_void:
374     case TST_wchar:
375     case TST_BFloat16:
376 #define GENERIC_IMAGE_TYPE(ImgType, Id) case TST_##ImgType##_t:
377 #include "clang/Basic/OpenCLImageTypes.def"
378       return false;
379 
380     case TST_decltype_auto:
381       // This must have an initializer, so can't be a function declaration,
382       // even if the initializer has function type.
383       return false;
384 
385     case TST_decltype:
386     case TST_typeofExpr:
387       if (Expr *E = DS.getRepAsExpr())
388         return E->getType()->isFunctionType();
389       return false;
390 
391     case TST_underlyingType:
392     case TST_typename:
393     case TST_typeofType: {
394       QualType QT = DS.getRepAsType().get();
395       if (QT.isNull())
396         return false;
397 
398       if (const LocInfoType *LIT = dyn_cast<LocInfoType>(QT))
399         QT = LIT->getType();
400 
401       if (QT.isNull())
402         return false;
403 
404       return QT->isFunctionType();
405     }
406   }
407 
408   llvm_unreachable("Invalid TypeSpecType!");
409 }
410 
411 bool Declarator::isStaticMember() {
412   assert(getContext() == DeclaratorContext::Member);
413   return getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_static ||
414          (getName().Kind == UnqualifiedIdKind::IK_OperatorFunctionId &&
415           CXXMethodDecl::isStaticOverloadedOperator(
416               getName().OperatorFunctionId.Operator));
417 }
418 
419 bool Declarator::isCtorOrDtor() {
420   return (getName().getKind() == UnqualifiedIdKind::IK_ConstructorName) ||
421          (getName().getKind() == UnqualifiedIdKind::IK_DestructorName);
422 }
423 
424 void DeclSpec::forEachCVRUQualifier(
425     llvm::function_ref<void(TQ, StringRef, SourceLocation)> Handle) {
426   if (TypeQualifiers & TQ_const)
427     Handle(TQ_const, "const", TQ_constLoc);
428   if (TypeQualifiers & TQ_volatile)
429     Handle(TQ_volatile, "volatile", TQ_volatileLoc);
430   if (TypeQualifiers & TQ_restrict)
431     Handle(TQ_restrict, "restrict", TQ_restrictLoc);
432   if (TypeQualifiers & TQ_unaligned)
433     Handle(TQ_unaligned, "unaligned", TQ_unalignedLoc);
434 }
435 
436 void DeclSpec::forEachQualifier(
437     llvm::function_ref<void(TQ, StringRef, SourceLocation)> Handle) {
438   forEachCVRUQualifier(Handle);
439   // FIXME: Add code below to iterate through the attributes and call Handle.
440 }
441 
442 bool DeclSpec::hasTagDefinition() const {
443   if (!TypeSpecOwned)
444     return false;
445   return cast<TagDecl>(getRepAsDecl())->isCompleteDefinition();
446 }
447 
448 /// getParsedSpecifiers - Return a bitmask of which flavors of specifiers this
449 /// declaration specifier includes.
450 ///
451 unsigned DeclSpec::getParsedSpecifiers() const {
452   unsigned Res = 0;
453   if (StorageClassSpec != SCS_unspecified ||
454       ThreadStorageClassSpec != TSCS_unspecified)
455     Res |= PQ_StorageClassSpecifier;
456 
457   if (TypeQualifiers != TQ_unspecified)
458     Res |= PQ_TypeQualifier;
459 
460   if (hasTypeSpecifier())
461     Res |= PQ_TypeSpecifier;
462 
463   if (FS_inline_specified || FS_virtual_specified || hasExplicitSpecifier() ||
464       FS_noreturn_specified || FS_forceinline_specified)
465     Res |= PQ_FunctionSpecifier;
466   return Res;
467 }
468 
469 template <class T> static bool BadSpecifier(T TNew, T TPrev,
470                                             const char *&PrevSpec,
471                                             unsigned &DiagID,
472                                             bool IsExtension = true) {
473   PrevSpec = DeclSpec::getSpecifierName(TPrev);
474   if (TNew != TPrev)
475     DiagID = diag::err_invalid_decl_spec_combination;
476   else
477     DiagID = IsExtension ? diag::ext_warn_duplicate_declspec :
478                            diag::warn_duplicate_declspec;
479   return true;
480 }
481 
482 const char *DeclSpec::getSpecifierName(DeclSpec::SCS S) {
483   switch (S) {
484   case DeclSpec::SCS_unspecified: return "unspecified";
485   case DeclSpec::SCS_typedef:     return "typedef";
486   case DeclSpec::SCS_extern:      return "extern";
487   case DeclSpec::SCS_static:      return "static";
488   case DeclSpec::SCS_auto:        return "auto";
489   case DeclSpec::SCS_register:    return "register";
490   case DeclSpec::SCS_private_extern: return "__private_extern__";
491   case DeclSpec::SCS_mutable:     return "mutable";
492   }
493   llvm_unreachable("Unknown typespec!");
494 }
495 
496 const char *DeclSpec::getSpecifierName(DeclSpec::TSCS S) {
497   switch (S) {
498   case DeclSpec::TSCS_unspecified:   return "unspecified";
499   case DeclSpec::TSCS___thread:      return "__thread";
500   case DeclSpec::TSCS_thread_local:  return "thread_local";
501   case DeclSpec::TSCS__Thread_local: return "_Thread_local";
502   }
503   llvm_unreachable("Unknown typespec!");
504 }
505 
506 const char *DeclSpec::getSpecifierName(TypeSpecifierWidth W) {
507   switch (W) {
508   case TypeSpecifierWidth::Unspecified:
509     return "unspecified";
510   case TypeSpecifierWidth::Short:
511     return "short";
512   case TypeSpecifierWidth::Long:
513     return "long";
514   case TypeSpecifierWidth::LongLong:
515     return "long long";
516   }
517   llvm_unreachable("Unknown typespec!");
518 }
519 
520 const char *DeclSpec::getSpecifierName(TSC C) {
521   switch (C) {
522   case TSC_unspecified: return "unspecified";
523   case TSC_imaginary:   return "imaginary";
524   case TSC_complex:     return "complex";
525   }
526   llvm_unreachable("Unknown typespec!");
527 }
528 
529 const char *DeclSpec::getSpecifierName(TypeSpecifierSign S) {
530   switch (S) {
531   case TypeSpecifierSign::Unspecified:
532     return "unspecified";
533   case TypeSpecifierSign::Signed:
534     return "signed";
535   case TypeSpecifierSign::Unsigned:
536     return "unsigned";
537   }
538   llvm_unreachable("Unknown typespec!");
539 }
540 
541 const char *DeclSpec::getSpecifierName(DeclSpec::TST T,
542                                        const PrintingPolicy &Policy) {
543   switch (T) {
544   case DeclSpec::TST_unspecified: return "unspecified";
545   case DeclSpec::TST_void:        return "void";
546   case DeclSpec::TST_char:        return "char";
547   case DeclSpec::TST_wchar:       return Policy.MSWChar ? "__wchar_t" : "wchar_t";
548   case DeclSpec::TST_char8:       return "char8_t";
549   case DeclSpec::TST_char16:      return "char16_t";
550   case DeclSpec::TST_char32:      return "char32_t";
551   case DeclSpec::TST_int:         return "int";
552   case DeclSpec::TST_int128:      return "__int128";
553   case DeclSpec::TST_extint:      return "_ExtInt";
554   case DeclSpec::TST_half:        return "half";
555   case DeclSpec::TST_float:       return "float";
556   case DeclSpec::TST_double:      return "double";
557   case DeclSpec::TST_accum:       return "_Accum";
558   case DeclSpec::TST_fract:       return "_Fract";
559   case DeclSpec::TST_float16:     return "_Float16";
560   case DeclSpec::TST_float128:    return "__float128";
561   case DeclSpec::TST_bool:        return Policy.Bool ? "bool" : "_Bool";
562   case DeclSpec::TST_decimal32:   return "_Decimal32";
563   case DeclSpec::TST_decimal64:   return "_Decimal64";
564   case DeclSpec::TST_decimal128:  return "_Decimal128";
565   case DeclSpec::TST_enum:        return "enum";
566   case DeclSpec::TST_class:       return "class";
567   case DeclSpec::TST_union:       return "union";
568   case DeclSpec::TST_struct:      return "struct";
569   case DeclSpec::TST_interface:   return "__interface";
570   case DeclSpec::TST_typename:    return "type-name";
571   case DeclSpec::TST_typeofType:
572   case DeclSpec::TST_typeofExpr:  return "typeof";
573   case DeclSpec::TST_auto:        return "auto";
574   case DeclSpec::TST_auto_type:   return "__auto_type";
575   case DeclSpec::TST_decltype:    return "(decltype)";
576   case DeclSpec::TST_decltype_auto: return "decltype(auto)";
577   case DeclSpec::TST_underlyingType: return "__underlying_type";
578   case DeclSpec::TST_unknown_anytype: return "__unknown_anytype";
579   case DeclSpec::TST_atomic: return "_Atomic";
580   case DeclSpec::TST_BFloat16: return "__bf16";
581 #define GENERIC_IMAGE_TYPE(ImgType, Id) \
582   case DeclSpec::TST_##ImgType##_t: \
583     return #ImgType "_t";
584 #include "clang/Basic/OpenCLImageTypes.def"
585   case DeclSpec::TST_error:       return "(error)";
586   }
587   llvm_unreachable("Unknown typespec!");
588 }
589 
590 const char *DeclSpec::getSpecifierName(ConstexprSpecKind C) {
591   switch (C) {
592   case ConstexprSpecKind::Unspecified:
593     return "unspecified";
594   case ConstexprSpecKind::Constexpr:
595     return "constexpr";
596   case ConstexprSpecKind::Consteval:
597     return "consteval";
598   case ConstexprSpecKind::Constinit:
599     return "constinit";
600   }
601   llvm_unreachable("Unknown ConstexprSpecKind");
602 }
603 
604 const char *DeclSpec::getSpecifierName(TQ T) {
605   switch (T) {
606   case DeclSpec::TQ_unspecified: return "unspecified";
607   case DeclSpec::TQ_const:       return "const";
608   case DeclSpec::TQ_restrict:    return "restrict";
609   case DeclSpec::TQ_volatile:    return "volatile";
610   case DeclSpec::TQ_atomic:      return "_Atomic";
611   case DeclSpec::TQ_unaligned:   return "__unaligned";
612   }
613   llvm_unreachable("Unknown typespec!");
614 }
615 
616 bool DeclSpec::SetStorageClassSpec(Sema &S, SCS SC, SourceLocation Loc,
617                                    const char *&PrevSpec,
618                                    unsigned &DiagID,
619                                    const PrintingPolicy &Policy) {
620   // OpenCL v1.1 s6.8g: "The extern, static, auto and register storage-class
621   // specifiers are not supported.
622   // It seems sensible to prohibit private_extern too
623   // The cl_clang_storage_class_specifiers extension enables support for
624   // these storage-class specifiers.
625   // OpenCL v1.2 s6.8 changes this to "The auto and register storage-class
626   // specifiers are not supported."
627   if (S.getLangOpts().OpenCL &&
628       !S.getOpenCLOptions().isAvailableOption(
629           "cl_clang_storage_class_specifiers", S.getLangOpts())) {
630     switch (SC) {
631     case SCS_extern:
632     case SCS_private_extern:
633     case SCS_static:
634       if (S.getLangOpts().OpenCLVersion < 120 &&
635           !S.getLangOpts().OpenCLCPlusPlus) {
636         DiagID = diag::err_opencl_unknown_type_specifier;
637         PrevSpec = getSpecifierName(SC);
638         return true;
639       }
640       break;
641     case SCS_auto:
642     case SCS_register:
643       DiagID   = diag::err_opencl_unknown_type_specifier;
644       PrevSpec = getSpecifierName(SC);
645       return true;
646     default:
647       break;
648     }
649   }
650 
651   if (StorageClassSpec != SCS_unspecified) {
652     // Maybe this is an attempt to use C++11 'auto' outside of C++11 mode.
653     bool isInvalid = true;
654     if (TypeSpecType == TST_unspecified && S.getLangOpts().CPlusPlus) {
655       if (SC == SCS_auto)
656         return SetTypeSpecType(TST_auto, Loc, PrevSpec, DiagID, Policy);
657       if (StorageClassSpec == SCS_auto) {
658         isInvalid = SetTypeSpecType(TST_auto, StorageClassSpecLoc,
659                                     PrevSpec, DiagID, Policy);
660         assert(!isInvalid && "auto SCS -> TST recovery failed");
661       }
662     }
663 
664     // Changing storage class is allowed only if the previous one
665     // was the 'extern' that is part of a linkage specification and
666     // the new storage class is 'typedef'.
667     if (isInvalid &&
668         !(SCS_extern_in_linkage_spec &&
669           StorageClassSpec == SCS_extern &&
670           SC == SCS_typedef))
671       return BadSpecifier(SC, (SCS)StorageClassSpec, PrevSpec, DiagID);
672   }
673   StorageClassSpec = SC;
674   StorageClassSpecLoc = Loc;
675   assert((unsigned)SC == StorageClassSpec && "SCS constants overflow bitfield");
676   return false;
677 }
678 
679 bool DeclSpec::SetStorageClassSpecThread(TSCS TSC, SourceLocation Loc,
680                                          const char *&PrevSpec,
681                                          unsigned &DiagID) {
682   if (ThreadStorageClassSpec != TSCS_unspecified)
683     return BadSpecifier(TSC, (TSCS)ThreadStorageClassSpec, PrevSpec, DiagID);
684 
685   ThreadStorageClassSpec = TSC;
686   ThreadStorageClassSpecLoc = Loc;
687   return false;
688 }
689 
690 /// These methods set the specified attribute of the DeclSpec, but return true
691 /// and ignore the request if invalid (e.g. "extern" then "auto" is
692 /// specified).
693 bool DeclSpec::SetTypeSpecWidth(TypeSpecifierWidth W, SourceLocation Loc,
694                                 const char *&PrevSpec, unsigned &DiagID,
695                                 const PrintingPolicy &Policy) {
696   // Overwrite TSWRange.Begin only if TypeSpecWidth was unspecified, so that
697   // for 'long long' we will keep the source location of the first 'long'.
698   if (getTypeSpecWidth() == TypeSpecifierWidth::Unspecified)
699     TSWRange.setBegin(Loc);
700   // Allow turning long -> long long.
701   else if (W != TypeSpecifierWidth::LongLong ||
702            getTypeSpecWidth() != TypeSpecifierWidth::Long)
703     return BadSpecifier(W, getTypeSpecWidth(), PrevSpec, DiagID);
704   TypeSpecWidth = static_cast<unsigned>(W);
705   // Remember location of the last 'long'
706   TSWRange.setEnd(Loc);
707   return false;
708 }
709 
710 bool DeclSpec::SetTypeSpecComplex(TSC C, SourceLocation Loc,
711                                   const char *&PrevSpec,
712                                   unsigned &DiagID) {
713   if (TypeSpecComplex != TSC_unspecified)
714     return BadSpecifier(C, (TSC)TypeSpecComplex, PrevSpec, DiagID);
715   TypeSpecComplex = C;
716   TSCLoc = Loc;
717   return false;
718 }
719 
720 bool DeclSpec::SetTypeSpecSign(TypeSpecifierSign S, SourceLocation Loc,
721                                const char *&PrevSpec, unsigned &DiagID) {
722   if (getTypeSpecSign() != TypeSpecifierSign::Unspecified)
723     return BadSpecifier(S, getTypeSpecSign(), PrevSpec, DiagID);
724   TypeSpecSign = static_cast<unsigned>(S);
725   TSSLoc = Loc;
726   return false;
727 }
728 
729 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
730                                const char *&PrevSpec,
731                                unsigned &DiagID,
732                                ParsedType Rep,
733                                const PrintingPolicy &Policy) {
734   return SetTypeSpecType(T, Loc, Loc, PrevSpec, DiagID, Rep, Policy);
735 }
736 
737 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation TagKwLoc,
738                                SourceLocation TagNameLoc,
739                                const char *&PrevSpec,
740                                unsigned &DiagID,
741                                ParsedType Rep,
742                                const PrintingPolicy &Policy) {
743   assert(isTypeRep(T) && "T does not store a type");
744   assert(Rep && "no type provided!");
745   if (TypeSpecType == TST_error)
746     return false;
747   if (TypeSpecType != TST_unspecified) {
748     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
749     DiagID = diag::err_invalid_decl_spec_combination;
750     return true;
751   }
752   TypeSpecType = T;
753   TypeRep = Rep;
754   TSTLoc = TagKwLoc;
755   TSTNameLoc = TagNameLoc;
756   TypeSpecOwned = false;
757   return false;
758 }
759 
760 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
761                                const char *&PrevSpec,
762                                unsigned &DiagID,
763                                Expr *Rep,
764                                const PrintingPolicy &Policy) {
765   assert(isExprRep(T) && "T does not store an expr");
766   assert(Rep && "no expression provided!");
767   if (TypeSpecType == TST_error)
768     return false;
769   if (TypeSpecType != TST_unspecified) {
770     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
771     DiagID = diag::err_invalid_decl_spec_combination;
772     return true;
773   }
774   TypeSpecType = T;
775   ExprRep = Rep;
776   TSTLoc = Loc;
777   TSTNameLoc = Loc;
778   TypeSpecOwned = false;
779   return false;
780 }
781 
782 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
783                                const char *&PrevSpec,
784                                unsigned &DiagID,
785                                Decl *Rep, bool Owned,
786                                const PrintingPolicy &Policy) {
787   return SetTypeSpecType(T, Loc, Loc, PrevSpec, DiagID, Rep, Owned, Policy);
788 }
789 
790 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation TagKwLoc,
791                                SourceLocation TagNameLoc,
792                                const char *&PrevSpec,
793                                unsigned &DiagID,
794                                Decl *Rep, bool Owned,
795                                const PrintingPolicy &Policy) {
796   assert(isDeclRep(T) && "T does not store a decl");
797   // Unlike the other cases, we don't assert that we actually get a decl.
798 
799   if (TypeSpecType == TST_error)
800     return false;
801   if (TypeSpecType != TST_unspecified) {
802     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
803     DiagID = diag::err_invalid_decl_spec_combination;
804     return true;
805   }
806   TypeSpecType = T;
807   DeclRep = Rep;
808   TSTLoc = TagKwLoc;
809   TSTNameLoc = TagNameLoc;
810   TypeSpecOwned = Owned && Rep != nullptr;
811   return false;
812 }
813 
814 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc, const char *&PrevSpec,
815                                unsigned &DiagID, TemplateIdAnnotation *Rep,
816                                const PrintingPolicy &Policy) {
817   assert(T == TST_auto || T == TST_decltype_auto);
818   ConstrainedAuto = true;
819   TemplateIdRep = Rep;
820   return SetTypeSpecType(T, Loc, PrevSpec, DiagID, Policy);
821 }
822 
823 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
824                                const char *&PrevSpec,
825                                unsigned &DiagID,
826                                const PrintingPolicy &Policy) {
827   assert(!isDeclRep(T) && !isTypeRep(T) && !isExprRep(T) &&
828          "rep required for these type-spec kinds!");
829   if (TypeSpecType == TST_error)
830     return false;
831   if (TypeSpecType != TST_unspecified) {
832     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
833     DiagID = diag::err_invalid_decl_spec_combination;
834     return true;
835   }
836   TSTLoc = Loc;
837   TSTNameLoc = Loc;
838   if (TypeAltiVecVector && (T == TST_bool) && !TypeAltiVecBool) {
839     TypeAltiVecBool = true;
840     return false;
841   }
842   TypeSpecType = T;
843   TypeSpecOwned = false;
844   return false;
845 }
846 
847 bool DeclSpec::SetTypeSpecSat(SourceLocation Loc, const char *&PrevSpec,
848                               unsigned &DiagID) {
849   // Cannot set twice
850   if (TypeSpecSat) {
851     DiagID = diag::warn_duplicate_declspec;
852     PrevSpec = "_Sat";
853     return true;
854   }
855   TypeSpecSat = true;
856   TSSatLoc = Loc;
857   return false;
858 }
859 
860 bool DeclSpec::SetTypeAltiVecVector(bool isAltiVecVector, SourceLocation Loc,
861                           const char *&PrevSpec, unsigned &DiagID,
862                           const PrintingPolicy &Policy) {
863   if (TypeSpecType == TST_error)
864     return false;
865   if (TypeSpecType != TST_unspecified) {
866     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
867     DiagID = diag::err_invalid_vector_decl_spec_combination;
868     return true;
869   }
870   TypeAltiVecVector = isAltiVecVector;
871   AltiVecLoc = Loc;
872   return false;
873 }
874 
875 bool DeclSpec::SetTypePipe(bool isPipe, SourceLocation Loc,
876                            const char *&PrevSpec, unsigned &DiagID,
877                            const PrintingPolicy &Policy) {
878   if (TypeSpecType == TST_error)
879     return false;
880   if (TypeSpecType != TST_unspecified) {
881     PrevSpec = DeclSpec::getSpecifierName((TST)TypeSpecType, Policy);
882     DiagID = diag::err_invalid_decl_spec_combination;
883     return true;
884   }
885 
886   if (isPipe) {
887     TypeSpecPipe = static_cast<unsigned>(TypeSpecifiersPipe::Pipe);
888   }
889   return false;
890 }
891 
892 bool DeclSpec::SetTypeAltiVecPixel(bool isAltiVecPixel, SourceLocation Loc,
893                           const char *&PrevSpec, unsigned &DiagID,
894                           const PrintingPolicy &Policy) {
895   if (TypeSpecType == TST_error)
896     return false;
897   if (!TypeAltiVecVector || TypeAltiVecPixel ||
898       (TypeSpecType != TST_unspecified)) {
899     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
900     DiagID = diag::err_invalid_pixel_decl_spec_combination;
901     return true;
902   }
903   TypeAltiVecPixel = isAltiVecPixel;
904   TSTLoc = Loc;
905   TSTNameLoc = Loc;
906   return false;
907 }
908 
909 bool DeclSpec::SetTypeAltiVecBool(bool isAltiVecBool, SourceLocation Loc,
910                                   const char *&PrevSpec, unsigned &DiagID,
911                                   const PrintingPolicy &Policy) {
912   if (TypeSpecType == TST_error)
913     return false;
914   if (!TypeAltiVecVector || TypeAltiVecBool ||
915       (TypeSpecType != TST_unspecified)) {
916     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
917     DiagID = diag::err_invalid_vector_bool_decl_spec;
918     return true;
919   }
920   TypeAltiVecBool = isAltiVecBool;
921   TSTLoc = Loc;
922   TSTNameLoc = Loc;
923   return false;
924 }
925 
926 bool DeclSpec::SetTypeSpecError() {
927   TypeSpecType = TST_error;
928   TypeSpecOwned = false;
929   TSTLoc = SourceLocation();
930   TSTNameLoc = SourceLocation();
931   return false;
932 }
933 
934 bool DeclSpec::SetExtIntType(SourceLocation KWLoc, Expr *BitsExpr,
935                              const char *&PrevSpec, unsigned &DiagID,
936                              const PrintingPolicy &Policy) {
937   assert(BitsExpr && "no expression provided!");
938   if (TypeSpecType == TST_error)
939     return false;
940 
941   if (TypeSpecType != TST_unspecified) {
942     PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
943     DiagID = diag::err_invalid_decl_spec_combination;
944     return true;
945   }
946 
947   TypeSpecType = TST_extint;
948   ExprRep = BitsExpr;
949   TSTLoc = KWLoc;
950   TSTNameLoc = KWLoc;
951   TypeSpecOwned = false;
952   return false;
953 }
954 
955 bool DeclSpec::SetTypeQual(TQ T, SourceLocation Loc, const char *&PrevSpec,
956                            unsigned &DiagID, const LangOptions &Lang) {
957   // Duplicates are permitted in C99 onwards, but are not permitted in C89 or
958   // C++.  However, since this is likely not what the user intended, we will
959   // always warn.  We do not need to set the qualifier's location since we
960   // already have it.
961   if (TypeQualifiers & T) {
962     bool IsExtension = true;
963     if (Lang.C99)
964       IsExtension = false;
965     return BadSpecifier(T, T, PrevSpec, DiagID, IsExtension);
966   }
967 
968   return SetTypeQual(T, Loc);
969 }
970 
971 bool DeclSpec::SetTypeQual(TQ T, SourceLocation Loc) {
972   TypeQualifiers |= T;
973 
974   switch (T) {
975   case TQ_unspecified: break;
976   case TQ_const:    TQ_constLoc = Loc; return false;
977   case TQ_restrict: TQ_restrictLoc = Loc; return false;
978   case TQ_volatile: TQ_volatileLoc = Loc; return false;
979   case TQ_unaligned: TQ_unalignedLoc = Loc; return false;
980   case TQ_atomic:   TQ_atomicLoc = Loc; return false;
981   }
982 
983   llvm_unreachable("Unknown type qualifier!");
984 }
985 
986 bool DeclSpec::setFunctionSpecInline(SourceLocation Loc, const char *&PrevSpec,
987                                      unsigned &DiagID) {
988   // 'inline inline' is ok.  However, since this is likely not what the user
989   // intended, we will always warn, similar to duplicates of type qualifiers.
990   if (FS_inline_specified) {
991     DiagID = diag::warn_duplicate_declspec;
992     PrevSpec = "inline";
993     return true;
994   }
995   FS_inline_specified = true;
996   FS_inlineLoc = Loc;
997   return false;
998 }
999 
1000 bool DeclSpec::setFunctionSpecForceInline(SourceLocation Loc, const char *&PrevSpec,
1001                                           unsigned &DiagID) {
1002   if (FS_forceinline_specified) {
1003     DiagID = diag::warn_duplicate_declspec;
1004     PrevSpec = "__forceinline";
1005     return true;
1006   }
1007   FS_forceinline_specified = true;
1008   FS_forceinlineLoc = Loc;
1009   return false;
1010 }
1011 
1012 bool DeclSpec::setFunctionSpecVirtual(SourceLocation Loc,
1013                                       const char *&PrevSpec,
1014                                       unsigned &DiagID) {
1015   // 'virtual virtual' is ok, but warn as this is likely not what the user
1016   // intended.
1017   if (FS_virtual_specified) {
1018     DiagID = diag::warn_duplicate_declspec;
1019     PrevSpec = "virtual";
1020     return true;
1021   }
1022   FS_virtual_specified = true;
1023   FS_virtualLoc = Loc;
1024   return false;
1025 }
1026 
1027 bool DeclSpec::setFunctionSpecExplicit(SourceLocation Loc,
1028                                        const char *&PrevSpec, unsigned &DiagID,
1029                                        ExplicitSpecifier ExplicitSpec,
1030                                        SourceLocation CloseParenLoc) {
1031   // 'explicit explicit' is ok, but warn as this is likely not what the user
1032   // intended.
1033   if (hasExplicitSpecifier()) {
1034     DiagID = (ExplicitSpec.getExpr() || FS_explicit_specifier.getExpr())
1035                  ? diag::err_duplicate_declspec
1036                  : diag::ext_warn_duplicate_declspec;
1037     PrevSpec = "explicit";
1038     return true;
1039   }
1040   FS_explicit_specifier = ExplicitSpec;
1041   FS_explicitLoc = Loc;
1042   FS_explicitCloseParenLoc = CloseParenLoc;
1043   return false;
1044 }
1045 
1046 bool DeclSpec::setFunctionSpecNoreturn(SourceLocation Loc,
1047                                        const char *&PrevSpec,
1048                                        unsigned &DiagID) {
1049   // '_Noreturn _Noreturn' is ok, but warn as this is likely not what the user
1050   // intended.
1051   if (FS_noreturn_specified) {
1052     DiagID = diag::warn_duplicate_declspec;
1053     PrevSpec = "_Noreturn";
1054     return true;
1055   }
1056   FS_noreturn_specified = true;
1057   FS_noreturnLoc = Loc;
1058   return false;
1059 }
1060 
1061 bool DeclSpec::SetFriendSpec(SourceLocation Loc, const char *&PrevSpec,
1062                              unsigned &DiagID) {
1063   if (Friend_specified) {
1064     PrevSpec = "friend";
1065     // Keep the later location, so that we can later diagnose ill-formed
1066     // declarations like 'friend class X friend;'. Per [class.friend]p3,
1067     // 'friend' must be the first token in a friend declaration that is
1068     // not a function declaration.
1069     FriendLoc = Loc;
1070     DiagID = diag::warn_duplicate_declspec;
1071     return true;
1072   }
1073 
1074   Friend_specified = true;
1075   FriendLoc = Loc;
1076   return false;
1077 }
1078 
1079 bool DeclSpec::setModulePrivateSpec(SourceLocation Loc, const char *&PrevSpec,
1080                                     unsigned &DiagID) {
1081   if (isModulePrivateSpecified()) {
1082     PrevSpec = "__module_private__";
1083     DiagID = diag::ext_warn_duplicate_declspec;
1084     return true;
1085   }
1086 
1087   ModulePrivateLoc = Loc;
1088   return false;
1089 }
1090 
1091 bool DeclSpec::SetConstexprSpec(ConstexprSpecKind ConstexprKind,
1092                                 SourceLocation Loc, const char *&PrevSpec,
1093                                 unsigned &DiagID) {
1094   if (getConstexprSpecifier() != ConstexprSpecKind::Unspecified)
1095     return BadSpecifier(ConstexprKind, getConstexprSpecifier(), PrevSpec,
1096                         DiagID);
1097   ConstexprSpecifier = static_cast<unsigned>(ConstexprKind);
1098   ConstexprLoc = Loc;
1099   return false;
1100 }
1101 
1102 void DeclSpec::SaveWrittenBuiltinSpecs() {
1103   writtenBS.Sign = static_cast<int>(getTypeSpecSign());
1104   writtenBS.Width = static_cast<int>(getTypeSpecWidth());
1105   writtenBS.Type = getTypeSpecType();
1106   // Search the list of attributes for the presence of a mode attribute.
1107   writtenBS.ModeAttr = getAttributes().hasAttribute(ParsedAttr::AT_Mode);
1108 }
1109 
1110 /// Finish - This does final analysis of the declspec, rejecting things like
1111 /// "_Imaginary" (lacking an FP type).  This returns a diagnostic to issue or
1112 /// diag::NUM_DIAGNOSTICS if there is no error.  After calling this method,
1113 /// DeclSpec is guaranteed self-consistent, even if an error occurred.
1114 void DeclSpec::Finish(Sema &S, const PrintingPolicy &Policy) {
1115   // Before possibly changing their values, save specs as written.
1116   SaveWrittenBuiltinSpecs();
1117 
1118   // Check the type specifier components first. No checking for an invalid
1119   // type.
1120   if (TypeSpecType == TST_error)
1121     return;
1122 
1123   // If decltype(auto) is used, no other type specifiers are permitted.
1124   if (TypeSpecType == TST_decltype_auto &&
1125       (getTypeSpecWidth() != TypeSpecifierWidth::Unspecified ||
1126        TypeSpecComplex != TSC_unspecified ||
1127        getTypeSpecSign() != TypeSpecifierSign::Unspecified ||
1128        TypeAltiVecVector || TypeAltiVecPixel || TypeAltiVecBool ||
1129        TypeQualifiers)) {
1130     const unsigned NumLocs = 9;
1131     SourceLocation ExtraLocs[NumLocs] = {
1132         TSWRange.getBegin(), TSCLoc,       TSSLoc,
1133         AltiVecLoc,          TQ_constLoc,  TQ_restrictLoc,
1134         TQ_volatileLoc,      TQ_atomicLoc, TQ_unalignedLoc};
1135     FixItHint Hints[NumLocs];
1136     SourceLocation FirstLoc;
1137     for (unsigned I = 0; I != NumLocs; ++I) {
1138       if (ExtraLocs[I].isValid()) {
1139         if (FirstLoc.isInvalid() ||
1140             S.getSourceManager().isBeforeInTranslationUnit(ExtraLocs[I],
1141                                                            FirstLoc))
1142           FirstLoc = ExtraLocs[I];
1143         Hints[I] = FixItHint::CreateRemoval(ExtraLocs[I]);
1144       }
1145     }
1146     TypeSpecWidth = static_cast<unsigned>(TypeSpecifierWidth::Unspecified);
1147     TypeSpecComplex = TSC_unspecified;
1148     TypeSpecSign = static_cast<unsigned>(TypeSpecifierSign::Unspecified);
1149     TypeAltiVecVector = TypeAltiVecPixel = TypeAltiVecBool = false;
1150     TypeQualifiers = 0;
1151     S.Diag(TSTLoc, diag::err_decltype_auto_cannot_be_combined)
1152       << Hints[0] << Hints[1] << Hints[2] << Hints[3]
1153       << Hints[4] << Hints[5] << Hints[6] << Hints[7];
1154   }
1155 
1156   // Validate and finalize AltiVec vector declspec.
1157   if (TypeAltiVecVector) {
1158     if (TypeAltiVecBool) {
1159       // Sign specifiers are not allowed with vector bool. (PIM 2.1)
1160       if (getTypeSpecSign() != TypeSpecifierSign::Unspecified) {
1161         S.Diag(TSSLoc, diag::err_invalid_vector_bool_decl_spec)
1162             << getSpecifierName(getTypeSpecSign());
1163       }
1164       // Only char/int are valid with vector bool prior to Power10.
1165       // Power10 adds instructions that produce vector bool data
1166       // for quadwords as well so allow vector bool __int128.
1167       if (((TypeSpecType != TST_unspecified) && (TypeSpecType != TST_char) &&
1168            (TypeSpecType != TST_int) && (TypeSpecType != TST_int128)) ||
1169           TypeAltiVecPixel) {
1170         S.Diag(TSTLoc, diag::err_invalid_vector_bool_decl_spec)
1171           << (TypeAltiVecPixel ? "__pixel" :
1172                                  getSpecifierName((TST)TypeSpecType, Policy));
1173       }
1174       // vector bool __int128 requires Power10.
1175       if ((TypeSpecType == TST_int128) &&
1176           (!S.Context.getTargetInfo().hasFeature("power10-vector")))
1177         S.Diag(TSTLoc, diag::err_invalid_vector_bool_int128_decl_spec);
1178 
1179       // Only 'short' and 'long long' are valid with vector bool. (PIM 2.1)
1180       if ((getTypeSpecWidth() != TypeSpecifierWidth::Unspecified) &&
1181           (getTypeSpecWidth() != TypeSpecifierWidth::Short) &&
1182           (getTypeSpecWidth() != TypeSpecifierWidth::LongLong))
1183         S.Diag(TSWRange.getBegin(), diag::err_invalid_vector_bool_decl_spec)
1184             << getSpecifierName(getTypeSpecWidth());
1185 
1186       // vector bool long long requires VSX support or ZVector.
1187       if ((getTypeSpecWidth() == TypeSpecifierWidth::LongLong) &&
1188           (!S.Context.getTargetInfo().hasFeature("vsx")) &&
1189           (!S.Context.getTargetInfo().hasFeature("power8-vector")) &&
1190           !S.getLangOpts().ZVector)
1191         S.Diag(TSTLoc, diag::err_invalid_vector_long_long_decl_spec);
1192 
1193       // Elements of vector bool are interpreted as unsigned. (PIM 2.1)
1194       if ((TypeSpecType == TST_char) || (TypeSpecType == TST_int) ||
1195           (TypeSpecType == TST_int128) ||
1196           (getTypeSpecWidth() != TypeSpecifierWidth::Unspecified))
1197         TypeSpecSign = static_cast<unsigned>(TypeSpecifierSign::Unsigned);
1198     } else if (TypeSpecType == TST_double) {
1199       // vector long double and vector long long double are never allowed.
1200       // vector double is OK for Power7 and later, and ZVector.
1201       if (getTypeSpecWidth() == TypeSpecifierWidth::Long ||
1202           getTypeSpecWidth() == TypeSpecifierWidth::LongLong)
1203         S.Diag(TSWRange.getBegin(),
1204                diag::err_invalid_vector_long_double_decl_spec);
1205       else if (!S.Context.getTargetInfo().hasFeature("vsx") &&
1206                !S.getLangOpts().ZVector)
1207         S.Diag(TSTLoc, diag::err_invalid_vector_double_decl_spec);
1208     } else if (TypeSpecType == TST_float) {
1209       // vector float is unsupported for ZVector unless we have the
1210       // vector-enhancements facility 1 (ISA revision 12).
1211       if (S.getLangOpts().ZVector &&
1212           !S.Context.getTargetInfo().hasFeature("arch12"))
1213         S.Diag(TSTLoc, diag::err_invalid_vector_float_decl_spec);
1214     } else if (getTypeSpecWidth() == TypeSpecifierWidth::Long) {
1215       // vector long is unsupported for ZVector and deprecated for AltiVec.
1216       // It has also been historically deprecated on AIX (as an alias for
1217       // "vector int" in both 32-bit and 64-bit modes). It was then made
1218       // unsupported in the Clang-based XL compiler since the deprecated type
1219       // has a number of conflicting semantics and continuing to support it
1220       // is a disservice to users.
1221       if (S.getLangOpts().ZVector ||
1222           S.Context.getTargetInfo().getTriple().isOSAIX())
1223         S.Diag(TSWRange.getBegin(), diag::err_invalid_vector_long_decl_spec);
1224       else
1225         S.Diag(TSWRange.getBegin(),
1226                diag::warn_vector_long_decl_spec_combination)
1227             << getSpecifierName((TST)TypeSpecType, Policy);
1228     }
1229 
1230     if (TypeAltiVecPixel) {
1231       //TODO: perform validation
1232       TypeSpecType = TST_int;
1233       TypeSpecSign = static_cast<unsigned>(TypeSpecifierSign::Unsigned);
1234       TypeSpecWidth = static_cast<unsigned>(TypeSpecifierWidth::Short);
1235       TypeSpecOwned = false;
1236     }
1237   }
1238 
1239   bool IsFixedPointType =
1240       TypeSpecType == TST_accum || TypeSpecType == TST_fract;
1241 
1242   // signed/unsigned are only valid with int/char/wchar_t/_Accum.
1243   if (getTypeSpecSign() != TypeSpecifierSign::Unspecified) {
1244     if (TypeSpecType == TST_unspecified)
1245       TypeSpecType = TST_int; // unsigned -> unsigned int, signed -> signed int.
1246     else if (TypeSpecType != TST_int && TypeSpecType != TST_int128 &&
1247              TypeSpecType != TST_char && TypeSpecType != TST_wchar &&
1248              !IsFixedPointType && TypeSpecType != TST_extint) {
1249       S.Diag(TSSLoc, diag::err_invalid_sign_spec)
1250         << getSpecifierName((TST)TypeSpecType, Policy);
1251       // signed double -> double.
1252       TypeSpecSign = static_cast<unsigned>(TypeSpecifierSign::Unspecified);
1253     }
1254   }
1255 
1256   // Validate the width of the type.
1257   switch (getTypeSpecWidth()) {
1258   case TypeSpecifierWidth::Unspecified:
1259     break;
1260   case TypeSpecifierWidth::Short:    // short int
1261   case TypeSpecifierWidth::LongLong: // long long int
1262     if (TypeSpecType == TST_unspecified)
1263       TypeSpecType = TST_int; // short -> short int, long long -> long long int.
1264     else if (!(TypeSpecType == TST_int ||
1265                (IsFixedPointType &&
1266                 getTypeSpecWidth() != TypeSpecifierWidth::LongLong))) {
1267       S.Diag(TSWRange.getBegin(), diag::err_invalid_width_spec)
1268           << (int)TypeSpecWidth << getSpecifierName((TST)TypeSpecType, Policy);
1269       TypeSpecType = TST_int;
1270       TypeSpecSat = false;
1271       TypeSpecOwned = false;
1272     }
1273     break;
1274   case TypeSpecifierWidth::Long: // long double, long int
1275     if (TypeSpecType == TST_unspecified)
1276       TypeSpecType = TST_int;  // long -> long int.
1277     else if (TypeSpecType != TST_int && TypeSpecType != TST_double &&
1278              !IsFixedPointType) {
1279       S.Diag(TSWRange.getBegin(), diag::err_invalid_width_spec)
1280           << (int)TypeSpecWidth << getSpecifierName((TST)TypeSpecType, Policy);
1281       TypeSpecType = TST_int;
1282       TypeSpecSat = false;
1283       TypeSpecOwned = false;
1284     }
1285     break;
1286   }
1287 
1288   // TODO: if the implementation does not implement _Complex or _Imaginary,
1289   // disallow their use.  Need information about the backend.
1290   if (TypeSpecComplex != TSC_unspecified) {
1291     if (TypeSpecType == TST_unspecified) {
1292       S.Diag(TSCLoc, diag::ext_plain_complex)
1293         << FixItHint::CreateInsertion(
1294                               S.getLocForEndOfToken(getTypeSpecComplexLoc()),
1295                                                  " double");
1296       TypeSpecType = TST_double;   // _Complex -> _Complex double.
1297     } else if (TypeSpecType == TST_int || TypeSpecType == TST_char ||
1298                TypeSpecType == TST_extint) {
1299       // Note that this intentionally doesn't include _Complex _Bool.
1300       if (!S.getLangOpts().CPlusPlus)
1301         S.Diag(TSTLoc, diag::ext_integer_complex);
1302     } else if (TypeSpecType != TST_float && TypeSpecType != TST_double &&
1303                TypeSpecType != TST_float128) {
1304       // FIXME: _Float16, __fp16?
1305       S.Diag(TSCLoc, diag::err_invalid_complex_spec)
1306         << getSpecifierName((TST)TypeSpecType, Policy);
1307       TypeSpecComplex = TSC_unspecified;
1308     }
1309   }
1310 
1311   // C11 6.7.1/3, C++11 [dcl.stc]p1, GNU TLS: __thread, thread_local and
1312   // _Thread_local can only appear with the 'static' and 'extern' storage class
1313   // specifiers. We also allow __private_extern__ as an extension.
1314   if (ThreadStorageClassSpec != TSCS_unspecified) {
1315     switch (StorageClassSpec) {
1316     case SCS_unspecified:
1317     case SCS_extern:
1318     case SCS_private_extern:
1319     case SCS_static:
1320       break;
1321     default:
1322       if (S.getSourceManager().isBeforeInTranslationUnit(
1323             getThreadStorageClassSpecLoc(), getStorageClassSpecLoc()))
1324         S.Diag(getStorageClassSpecLoc(),
1325              diag::err_invalid_decl_spec_combination)
1326           << DeclSpec::getSpecifierName(getThreadStorageClassSpec())
1327           << SourceRange(getThreadStorageClassSpecLoc());
1328       else
1329         S.Diag(getThreadStorageClassSpecLoc(),
1330              diag::err_invalid_decl_spec_combination)
1331           << DeclSpec::getSpecifierName(getStorageClassSpec())
1332           << SourceRange(getStorageClassSpecLoc());
1333       // Discard the thread storage class specifier to recover.
1334       ThreadStorageClassSpec = TSCS_unspecified;
1335       ThreadStorageClassSpecLoc = SourceLocation();
1336     }
1337   }
1338 
1339   // If no type specifier was provided and we're parsing a language where
1340   // the type specifier is not optional, but we got 'auto' as a storage
1341   // class specifier, then assume this is an attempt to use C++0x's 'auto'
1342   // type specifier.
1343   if (S.getLangOpts().CPlusPlus &&
1344       TypeSpecType == TST_unspecified && StorageClassSpec == SCS_auto) {
1345     TypeSpecType = TST_auto;
1346     StorageClassSpec = SCS_unspecified;
1347     TSTLoc = TSTNameLoc = StorageClassSpecLoc;
1348     StorageClassSpecLoc = SourceLocation();
1349   }
1350   // Diagnose if we've recovered from an ill-formed 'auto' storage class
1351   // specifier in a pre-C++11 dialect of C++.
1352   if (!S.getLangOpts().CPlusPlus11 && TypeSpecType == TST_auto)
1353     S.Diag(TSTLoc, diag::ext_auto_type_specifier);
1354   if (S.getLangOpts().CPlusPlus && !S.getLangOpts().CPlusPlus11 &&
1355       StorageClassSpec == SCS_auto)
1356     S.Diag(StorageClassSpecLoc, diag::warn_auto_storage_class)
1357       << FixItHint::CreateRemoval(StorageClassSpecLoc);
1358   if (TypeSpecType == TST_char8)
1359     S.Diag(TSTLoc, diag::warn_cxx17_compat_unicode_type);
1360   else if (TypeSpecType == TST_char16 || TypeSpecType == TST_char32)
1361     S.Diag(TSTLoc, diag::warn_cxx98_compat_unicode_type)
1362       << (TypeSpecType == TST_char16 ? "char16_t" : "char32_t");
1363   if (getConstexprSpecifier() == ConstexprSpecKind::Constexpr)
1364     S.Diag(ConstexprLoc, diag::warn_cxx98_compat_constexpr);
1365   else if (getConstexprSpecifier() == ConstexprSpecKind::Consteval)
1366     S.Diag(ConstexprLoc, diag::warn_cxx20_compat_consteval);
1367   else if (getConstexprSpecifier() == ConstexprSpecKind::Constinit)
1368     S.Diag(ConstexprLoc, diag::warn_cxx20_compat_constinit);
1369   // C++ [class.friend]p6:
1370   //   No storage-class-specifier shall appear in the decl-specifier-seq
1371   //   of a friend declaration.
1372   if (isFriendSpecified() &&
1373       (getStorageClassSpec() || getThreadStorageClassSpec())) {
1374     SmallString<32> SpecName;
1375     SourceLocation SCLoc;
1376     FixItHint StorageHint, ThreadHint;
1377 
1378     if (DeclSpec::SCS SC = getStorageClassSpec()) {
1379       SpecName = getSpecifierName(SC);
1380       SCLoc = getStorageClassSpecLoc();
1381       StorageHint = FixItHint::CreateRemoval(SCLoc);
1382     }
1383 
1384     if (DeclSpec::TSCS TSC = getThreadStorageClassSpec()) {
1385       if (!SpecName.empty()) SpecName += " ";
1386       SpecName += getSpecifierName(TSC);
1387       SCLoc = getThreadStorageClassSpecLoc();
1388       ThreadHint = FixItHint::CreateRemoval(SCLoc);
1389     }
1390 
1391     S.Diag(SCLoc, diag::err_friend_decl_spec)
1392       << SpecName << StorageHint << ThreadHint;
1393 
1394     ClearStorageClassSpecs();
1395   }
1396 
1397   // C++11 [dcl.fct.spec]p5:
1398   //   The virtual specifier shall be used only in the initial
1399   //   declaration of a non-static class member function;
1400   // C++11 [dcl.fct.spec]p6:
1401   //   The explicit specifier shall be used only in the declaration of
1402   //   a constructor or conversion function within its class
1403   //   definition;
1404   if (isFriendSpecified() && (isVirtualSpecified() || hasExplicitSpecifier())) {
1405     StringRef Keyword;
1406     FixItHint Hint;
1407     SourceLocation SCLoc;
1408 
1409     if (isVirtualSpecified()) {
1410       Keyword = "virtual";
1411       SCLoc = getVirtualSpecLoc();
1412       Hint = FixItHint::CreateRemoval(SCLoc);
1413     } else {
1414       Keyword = "explicit";
1415       SCLoc = getExplicitSpecLoc();
1416       Hint = FixItHint::CreateRemoval(getExplicitSpecRange());
1417     }
1418 
1419     S.Diag(SCLoc, diag::err_friend_decl_spec)
1420       << Keyword << Hint;
1421 
1422     FS_virtual_specified = false;
1423     FS_explicit_specifier = ExplicitSpecifier();
1424     FS_virtualLoc = FS_explicitLoc = SourceLocation();
1425   }
1426 
1427   assert(!TypeSpecOwned || isDeclRep((TST) TypeSpecType));
1428 
1429   // Okay, now we can infer the real type.
1430 
1431   // TODO: return "auto function" and other bad things based on the real type.
1432 
1433   // 'data definition has no type or storage class'?
1434 }
1435 
1436 bool DeclSpec::isMissingDeclaratorOk() {
1437   TST tst = getTypeSpecType();
1438   return isDeclRep(tst) && getRepAsDecl() != nullptr &&
1439     StorageClassSpec != DeclSpec::SCS_typedef;
1440 }
1441 
1442 void UnqualifiedId::setOperatorFunctionId(SourceLocation OperatorLoc,
1443                                           OverloadedOperatorKind Op,
1444                                           SourceLocation SymbolLocations[3]) {
1445   Kind = UnqualifiedIdKind::IK_OperatorFunctionId;
1446   StartLocation = OperatorLoc;
1447   EndLocation = OperatorLoc;
1448   new (&OperatorFunctionId) struct OFI;
1449   OperatorFunctionId.Operator = Op;
1450   for (unsigned I = 0; I != 3; ++I) {
1451     OperatorFunctionId.SymbolLocations[I] = SymbolLocations[I];
1452 
1453     if (SymbolLocations[I].isValid())
1454       EndLocation = SymbolLocations[I];
1455   }
1456 }
1457 
1458 bool VirtSpecifiers::SetSpecifier(Specifier VS, SourceLocation Loc,
1459                                   const char *&PrevSpec) {
1460   if (!FirstLocation.isValid())
1461     FirstLocation = Loc;
1462   LastLocation = Loc;
1463   LastSpecifier = VS;
1464 
1465   if (Specifiers & VS) {
1466     PrevSpec = getSpecifierName(VS);
1467     return true;
1468   }
1469 
1470   Specifiers |= VS;
1471 
1472   switch (VS) {
1473   default: llvm_unreachable("Unknown specifier!");
1474   case VS_Override: VS_overrideLoc = Loc; break;
1475   case VS_GNU_Final:
1476   case VS_Sealed:
1477   case VS_Final:    VS_finalLoc = Loc; break;
1478   case VS_Abstract: VS_abstractLoc = Loc; break;
1479   }
1480 
1481   return false;
1482 }
1483 
1484 const char *VirtSpecifiers::getSpecifierName(Specifier VS) {
1485   switch (VS) {
1486   default: llvm_unreachable("Unknown specifier");
1487   case VS_Override: return "override";
1488   case VS_Final: return "final";
1489   case VS_GNU_Final: return "__final";
1490   case VS_Sealed: return "sealed";
1491   case VS_Abstract: return "abstract";
1492   }
1493 }
1494