1 //===------- SemaTemplate.cpp - Semantic Analysis for C++ Templates -------===/
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //===----------------------------------------------------------------------===/
9 // This file implements semantic analysis for C++ templates.
10 //===----------------------------------------------------------------------===/
12 #include "TreeTransform.h"
13 #include "clang/AST/ASTConsumer.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/DeclFriend.h"
16 #include "clang/AST/DeclTemplate.h"
17 #include "clang/AST/Expr.h"
18 #include "clang/AST/ExprCXX.h"
19 #include "clang/AST/RecursiveASTVisitor.h"
20 #include "clang/AST/TypeVisitor.h"
21 #include "clang/Basic/LangOptions.h"
22 #include "clang/Basic/PartialDiagnostic.h"
23 #include "clang/Basic/TargetInfo.h"
24 #include "clang/Sema/DeclSpec.h"
25 #include "clang/Sema/Lookup.h"
26 #include "clang/Sema/ParsedTemplate.h"
27 #include "clang/Sema/Scope.h"
28 #include "clang/Sema/SemaInternal.h"
29 #include "clang/Sema/Template.h"
30 #include "clang/Sema/TemplateDeduction.h"
31 #include "llvm/ADT/SmallBitVector.h"
32 #include "llvm/ADT/SmallString.h"
33 #include "llvm/ADT/StringExtras.h"
34 using namespace clang;
37 // Exported for use by Parser.
39 clang::getTemplateParamsRange(TemplateParameterList const * const *Ps,
41 if (!N) return SourceRange();
42 return SourceRange(Ps[0]->getTemplateLoc(), Ps[N-1]->getRAngleLoc());
45 /// \brief Determine whether the declaration found is acceptable as the name
46 /// of a template and, if so, return that template declaration. Otherwise,
48 static NamedDecl *isAcceptableTemplateName(ASTContext &Context,
50 bool AllowFunctionTemplates) {
51 NamedDecl *D = Orig->getUnderlyingDecl();
53 if (isa<TemplateDecl>(D)) {
54 if (!AllowFunctionTemplates && isa<FunctionTemplateDecl>(D))
60 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
61 // C++ [temp.local]p1:
62 // Like normal (non-template) classes, class templates have an
63 // injected-class-name (Clause 9). The injected-class-name
64 // can be used with or without a template-argument-list. When
65 // it is used without a template-argument-list, it is
66 // equivalent to the injected-class-name followed by the
67 // template-parameters of the class template enclosed in
68 // <>. When it is used with a template-argument-list, it
69 // refers to the specified class template specialization,
70 // which could be the current specialization or another
72 if (Record->isInjectedClassName()) {
73 Record = cast<CXXRecordDecl>(Record->getDeclContext());
74 if (Record->getDescribedClassTemplate())
75 return Record->getDescribedClassTemplate();
77 if (ClassTemplateSpecializationDecl *Spec
78 = dyn_cast<ClassTemplateSpecializationDecl>(Record))
79 return Spec->getSpecializedTemplate();
88 void Sema::FilterAcceptableTemplateNames(LookupResult &R,
89 bool AllowFunctionTemplates) {
90 // The set of class templates we've already seen.
91 llvm::SmallPtrSet<ClassTemplateDecl *, 8> ClassTemplates;
92 LookupResult::Filter filter = R.makeFilter();
93 while (filter.hasNext()) {
94 NamedDecl *Orig = filter.next();
95 NamedDecl *Repl = isAcceptableTemplateName(Context, Orig,
96 AllowFunctionTemplates);
99 else if (Repl != Orig) {
101 // C++ [temp.local]p3:
102 // A lookup that finds an injected-class-name (10.2) can result in an
103 // ambiguity in certain cases (for example, if it is found in more than
104 // one base class). If all of the injected-class-names that are found
105 // refer to specializations of the same class template, and if the name
106 // is used as a template-name, the reference refers to the class
107 // template itself and not a specialization thereof, and is not
109 if (ClassTemplateDecl *ClassTmpl = dyn_cast<ClassTemplateDecl>(Repl))
110 if (!ClassTemplates.insert(ClassTmpl).second) {
115 // FIXME: we promote access to public here as a workaround to
116 // the fact that LookupResult doesn't let us remember that we
117 // found this template through a particular injected class name,
118 // which means we end up doing nasty things to the invariants.
119 // Pretending that access is public is *much* safer.
120 filter.replace(Repl, AS_public);
126 bool Sema::hasAnyAcceptableTemplateNames(LookupResult &R,
127 bool AllowFunctionTemplates) {
128 for (LookupResult::iterator I = R.begin(), IEnd = R.end(); I != IEnd; ++I)
129 if (isAcceptableTemplateName(Context, *I, AllowFunctionTemplates))
135 TemplateNameKind Sema::isTemplateName(Scope *S,
137 bool hasTemplateKeyword,
139 ParsedType ObjectTypePtr,
140 bool EnteringContext,
141 TemplateTy &TemplateResult,
142 bool &MemberOfUnknownSpecialization) {
143 assert(getLangOpts().CPlusPlus && "No template names in C!");
145 DeclarationName TName;
146 MemberOfUnknownSpecialization = false;
148 switch (Name.getKind()) {
149 case UnqualifiedId::IK_Identifier:
150 TName = DeclarationName(Name.Identifier);
153 case UnqualifiedId::IK_OperatorFunctionId:
154 TName = Context.DeclarationNames.getCXXOperatorName(
155 Name.OperatorFunctionId.Operator);
158 case UnqualifiedId::IK_LiteralOperatorId:
159 TName = Context.DeclarationNames.getCXXLiteralOperatorName(Name.Identifier);
163 return TNK_Non_template;
166 QualType ObjectType = ObjectTypePtr.get();
168 LookupResult R(*this, TName, Name.getLocStart(), LookupOrdinaryName);
169 LookupTemplateName(R, S, SS, ObjectType, EnteringContext,
170 MemberOfUnknownSpecialization);
171 if (R.empty()) return TNK_Non_template;
172 if (R.isAmbiguous()) {
173 // Suppress diagnostics; we'll redo this lookup later.
174 R.suppressDiagnostics();
176 // FIXME: we might have ambiguous templates, in which case we
177 // should at least parse them properly!
178 return TNK_Non_template;
181 TemplateName Template;
182 TemplateNameKind TemplateKind;
184 unsigned ResultCount = R.end() - R.begin();
185 if (ResultCount > 1) {
186 // We assume that we'll preserve the qualifier from a function
187 // template name in other ways.
188 Template = Context.getOverloadedTemplateName(R.begin(), R.end());
189 TemplateKind = TNK_Function_template;
191 // We'll do this lookup again later.
192 R.suppressDiagnostics();
194 TemplateDecl *TD = cast<TemplateDecl>((*R.begin())->getUnderlyingDecl());
196 if (SS.isSet() && !SS.isInvalid()) {
197 NestedNameSpecifier *Qualifier = SS.getScopeRep();
198 Template = Context.getQualifiedTemplateName(Qualifier,
199 hasTemplateKeyword, TD);
201 Template = TemplateName(TD);
204 if (isa<FunctionTemplateDecl>(TD)) {
205 TemplateKind = TNK_Function_template;
207 // We'll do this lookup again later.
208 R.suppressDiagnostics();
210 assert(isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) ||
211 isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD));
213 isa<VarTemplateDecl>(TD) ? TNK_Var_template : TNK_Type_template;
217 TemplateResult = TemplateTy::make(Template);
221 bool Sema::DiagnoseUnknownTemplateName(const IdentifierInfo &II,
222 SourceLocation IILoc,
224 const CXXScopeSpec *SS,
225 TemplateTy &SuggestedTemplate,
226 TemplateNameKind &SuggestedKind) {
227 // We can't recover unless there's a dependent scope specifier preceding the
229 // FIXME: Typo correction?
230 if (!SS || !SS->isSet() || !isDependentScopeSpecifier(*SS) ||
231 computeDeclContext(*SS))
234 // The code is missing a 'template' keyword prior to the dependent template
236 NestedNameSpecifier *Qualifier = (NestedNameSpecifier*)SS->getScopeRep();
237 Diag(IILoc, diag::err_template_kw_missing)
238 << Qualifier << II.getName()
239 << FixItHint::CreateInsertion(IILoc, "template ");
241 = TemplateTy::make(Context.getDependentTemplateName(Qualifier, &II));
242 SuggestedKind = TNK_Dependent_template_name;
246 void Sema::LookupTemplateName(LookupResult &Found,
247 Scope *S, CXXScopeSpec &SS,
249 bool EnteringContext,
250 bool &MemberOfUnknownSpecialization) {
251 // Determine where to perform name lookup
252 MemberOfUnknownSpecialization = false;
253 DeclContext *LookupCtx = nullptr;
254 bool isDependent = false;
255 if (!ObjectType.isNull()) {
256 // This nested-name-specifier occurs in a member access expression, e.g.,
257 // x->B::f, and we are looking into the type of the object.
258 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist");
259 LookupCtx = computeDeclContext(ObjectType);
260 isDependent = ObjectType->isDependentType();
261 assert((isDependent || !ObjectType->isIncompleteType() ||
262 ObjectType->castAs<TagType>()->isBeingDefined()) &&
263 "Caller should have completed object type");
265 // Template names cannot appear inside an Objective-C class or object type.
266 if (ObjectType->isObjCObjectOrInterfaceType()) {
270 } else if (SS.isSet()) {
271 // This nested-name-specifier occurs after another nested-name-specifier,
272 // so long into the context associated with the prior nested-name-specifier.
273 LookupCtx = computeDeclContext(SS, EnteringContext);
274 isDependent = isDependentScopeSpecifier(SS);
276 // The declaration context must be complete.
277 if (LookupCtx && RequireCompleteDeclContext(SS, LookupCtx))
281 bool ObjectTypeSearchedInScope = false;
282 bool AllowFunctionTemplatesInLookup = true;
284 // Perform "qualified" name lookup into the declaration context we
285 // computed, which is either the type of the base of a member access
286 // expression or the declaration context associated with a prior
287 // nested-name-specifier.
288 LookupQualifiedName(Found, LookupCtx);
289 if (!ObjectType.isNull() && Found.empty()) {
290 // C++ [basic.lookup.classref]p1:
291 // In a class member access expression (5.2.5), if the . or -> token is
292 // immediately followed by an identifier followed by a <, the
293 // identifier must be looked up to determine whether the < is the
294 // beginning of a template argument list (14.2) or a less-than operator.
295 // The identifier is first looked up in the class of the object
296 // expression. If the identifier is not found, it is then looked up in
297 // the context of the entire postfix-expression and shall name a class
298 // or function template.
299 if (S) LookupName(Found, S);
300 ObjectTypeSearchedInScope = true;
301 AllowFunctionTemplatesInLookup = false;
303 } else if (isDependent && (!S || ObjectType.isNull())) {
304 // We cannot look into a dependent object type or nested nme
306 MemberOfUnknownSpecialization = true;
309 // Perform unqualified name lookup in the current scope.
310 LookupName(Found, S);
312 if (!ObjectType.isNull())
313 AllowFunctionTemplatesInLookup = false;
316 if (Found.empty() && !isDependent) {
317 // If we did not find any names, attempt to correct any typos.
318 DeclarationName Name = Found.getLookupName();
320 // Simple filter callback that, for keywords, only accepts the C++ *_cast
321 auto FilterCCC = llvm::make_unique<CorrectionCandidateCallback>();
322 FilterCCC->WantTypeSpecifiers = false;
323 FilterCCC->WantExpressionKeywords = false;
324 FilterCCC->WantRemainingKeywords = false;
325 FilterCCC->WantCXXNamedCasts = true;
326 if (TypoCorrection Corrected = CorrectTypo(
327 Found.getLookupNameInfo(), Found.getLookupKind(), S, &SS,
328 std::move(FilterCCC), CTK_ErrorRecovery, LookupCtx)) {
329 Found.setLookupName(Corrected.getCorrection());
330 if (Corrected.getCorrectionDecl())
331 Found.addDecl(Corrected.getCorrectionDecl());
332 FilterAcceptableTemplateNames(Found);
333 if (!Found.empty()) {
335 std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
336 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
337 Name.getAsString() == CorrectedStr;
338 diagnoseTypo(Corrected, PDiag(diag::err_no_member_template_suggest)
339 << Name << LookupCtx << DroppedSpecifier
342 diagnoseTypo(Corrected, PDiag(diag::err_no_template_suggest) << Name);
346 Found.setLookupName(Name);
350 FilterAcceptableTemplateNames(Found, AllowFunctionTemplatesInLookup);
353 MemberOfUnknownSpecialization = true;
357 if (S && !ObjectType.isNull() && !ObjectTypeSearchedInScope &&
358 !getLangOpts().CPlusPlus11) {
359 // C++03 [basic.lookup.classref]p1:
360 // [...] If the lookup in the class of the object expression finds a
361 // template, the name is also looked up in the context of the entire
362 // postfix-expression and [...]
364 // Note: C++11 does not perform this second lookup.
365 LookupResult FoundOuter(*this, Found.getLookupName(), Found.getNameLoc(),
367 LookupName(FoundOuter, S);
368 FilterAcceptableTemplateNames(FoundOuter, /*AllowFunctionTemplates=*/false);
370 if (FoundOuter.empty()) {
371 // - if the name is not found, the name found in the class of the
372 // object expression is used, otherwise
373 } else if (!FoundOuter.getAsSingle<ClassTemplateDecl>() ||
374 FoundOuter.isAmbiguous()) {
375 // - if the name is found in the context of the entire
376 // postfix-expression and does not name a class template, the name
377 // found in the class of the object expression is used, otherwise
379 } else if (!Found.isSuppressingDiagnostics()) {
380 // - if the name found is a class template, it must refer to the same
381 // entity as the one found in the class of the object expression,
382 // otherwise the program is ill-formed.
383 if (!Found.isSingleResult() ||
384 Found.getFoundDecl()->getCanonicalDecl()
385 != FoundOuter.getFoundDecl()->getCanonicalDecl()) {
386 Diag(Found.getNameLoc(),
387 diag::ext_nested_name_member_ref_lookup_ambiguous)
388 << Found.getLookupName()
390 Diag(Found.getRepresentativeDecl()->getLocation(),
391 diag::note_ambig_member_ref_object_type)
393 Diag(FoundOuter.getFoundDecl()->getLocation(),
394 diag::note_ambig_member_ref_scope);
396 // Recover by taking the template that we found in the object
397 // expression's type.
403 /// ActOnDependentIdExpression - Handle a dependent id-expression that
404 /// was just parsed. This is only possible with an explicit scope
405 /// specifier naming a dependent type.
407 Sema::ActOnDependentIdExpression(const CXXScopeSpec &SS,
408 SourceLocation TemplateKWLoc,
409 const DeclarationNameInfo &NameInfo,
410 bool isAddressOfOperand,
411 const TemplateArgumentListInfo *TemplateArgs) {
412 DeclContext *DC = getFunctionLevelDeclContext();
414 if (!isAddressOfOperand &&
415 isa<CXXMethodDecl>(DC) &&
416 cast<CXXMethodDecl>(DC)->isInstance()) {
417 QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType(Context);
419 // Since the 'this' expression is synthesized, we don't need to
420 // perform the double-lookup check.
421 NamedDecl *FirstQualifierInScope = nullptr;
423 return CXXDependentScopeMemberExpr::Create(
424 Context, /*This*/ nullptr, ThisType, /*IsArrow*/ true,
425 /*Op*/ SourceLocation(), SS.getWithLocInContext(Context), TemplateKWLoc,
426 FirstQualifierInScope, NameInfo, TemplateArgs);
429 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
433 Sema::BuildDependentDeclRefExpr(const CXXScopeSpec &SS,
434 SourceLocation TemplateKWLoc,
435 const DeclarationNameInfo &NameInfo,
436 const TemplateArgumentListInfo *TemplateArgs) {
437 return DependentScopeDeclRefExpr::Create(
438 Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo,
442 /// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining
443 /// that the template parameter 'PrevDecl' is being shadowed by a new
444 /// declaration at location Loc. Returns true to indicate that this is
445 /// an error, and false otherwise.
446 void Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl) {
447 assert(PrevDecl->isTemplateParameter() && "Not a template parameter");
449 // Microsoft Visual C++ permits template parameters to be shadowed.
450 if (getLangOpts().MicrosoftExt)
453 // C++ [temp.local]p4:
454 // A template-parameter shall not be redeclared within its
455 // scope (including nested scopes).
456 Diag(Loc, diag::err_template_param_shadow)
457 << cast<NamedDecl>(PrevDecl)->getDeclName();
458 Diag(PrevDecl->getLocation(), diag::note_template_param_here);
462 /// AdjustDeclIfTemplate - If the given decl happens to be a template, reset
463 /// the parameter D to reference the templated declaration and return a pointer
464 /// to the template declaration. Otherwise, do nothing to D and return null.
465 TemplateDecl *Sema::AdjustDeclIfTemplate(Decl *&D) {
466 if (TemplateDecl *Temp = dyn_cast_or_null<TemplateDecl>(D)) {
467 D = Temp->getTemplatedDecl();
473 ParsedTemplateArgument ParsedTemplateArgument::getTemplatePackExpansion(
474 SourceLocation EllipsisLoc) const {
475 assert(Kind == Template &&
476 "Only template template arguments can be pack expansions here");
477 assert(getAsTemplate().get().containsUnexpandedParameterPack() &&
478 "Template template argument pack expansion without packs");
479 ParsedTemplateArgument Result(*this);
480 Result.EllipsisLoc = EllipsisLoc;
484 static TemplateArgumentLoc translateTemplateArgument(Sema &SemaRef,
485 const ParsedTemplateArgument &Arg) {
487 switch (Arg.getKind()) {
488 case ParsedTemplateArgument::Type: {
490 QualType T = SemaRef.GetTypeFromParser(Arg.getAsType(), &DI);
492 DI = SemaRef.Context.getTrivialTypeSourceInfo(T, Arg.getLocation());
493 return TemplateArgumentLoc(TemplateArgument(T), DI);
496 case ParsedTemplateArgument::NonType: {
497 Expr *E = static_cast<Expr *>(Arg.getAsExpr());
498 return TemplateArgumentLoc(TemplateArgument(E), E);
501 case ParsedTemplateArgument::Template: {
502 TemplateName Template = Arg.getAsTemplate().get();
503 TemplateArgument TArg;
504 if (Arg.getEllipsisLoc().isValid())
505 TArg = TemplateArgument(Template, Optional<unsigned int>());
508 return TemplateArgumentLoc(TArg,
509 Arg.getScopeSpec().getWithLocInContext(
512 Arg.getEllipsisLoc());
516 llvm_unreachable("Unhandled parsed template argument");
519 /// \brief Translates template arguments as provided by the parser
520 /// into template arguments used by semantic analysis.
521 void Sema::translateTemplateArguments(const ASTTemplateArgsPtr &TemplateArgsIn,
522 TemplateArgumentListInfo &TemplateArgs) {
523 for (unsigned I = 0, Last = TemplateArgsIn.size(); I != Last; ++I)
524 TemplateArgs.addArgument(translateTemplateArgument(*this,
528 static void maybeDiagnoseTemplateParameterShadow(Sema &SemaRef, Scope *S,
530 IdentifierInfo *Name) {
531 NamedDecl *PrevDecl = SemaRef.LookupSingleName(
532 S, Name, Loc, Sema::LookupOrdinaryName, Sema::ForRedeclaration);
533 if (PrevDecl && PrevDecl->isTemplateParameter())
534 SemaRef.DiagnoseTemplateParameterShadow(Loc, PrevDecl);
537 /// ActOnTypeParameter - Called when a C++ template type parameter
538 /// (e.g., "typename T") has been parsed. Typename specifies whether
539 /// the keyword "typename" was used to declare the type parameter
540 /// (otherwise, "class" was used), and KeyLoc is the location of the
541 /// "class" or "typename" keyword. ParamName is the name of the
542 /// parameter (NULL indicates an unnamed template parameter) and
543 /// ParamNameLoc is the location of the parameter name (if any).
544 /// If the type parameter has a default argument, it will be added
545 /// later via ActOnTypeParameterDefault.
546 Decl *Sema::ActOnTypeParameter(Scope *S, bool Typename,
547 SourceLocation EllipsisLoc,
548 SourceLocation KeyLoc,
549 IdentifierInfo *ParamName,
550 SourceLocation ParamNameLoc,
551 unsigned Depth, unsigned Position,
552 SourceLocation EqualLoc,
553 ParsedType DefaultArg) {
554 assert(S->isTemplateParamScope() &&
555 "Template type parameter not in template parameter scope!");
556 bool Invalid = false;
558 SourceLocation Loc = ParamNameLoc;
562 bool IsParameterPack = EllipsisLoc.isValid();
563 TemplateTypeParmDecl *Param
564 = TemplateTypeParmDecl::Create(Context, Context.getTranslationUnitDecl(),
565 KeyLoc, Loc, Depth, Position, ParamName,
566 Typename, IsParameterPack);
567 Param->setAccess(AS_public);
569 Param->setInvalidDecl();
572 maybeDiagnoseTemplateParameterShadow(*this, S, ParamNameLoc, ParamName);
574 // Add the template parameter into the current scope.
576 IdResolver.AddDecl(Param);
579 // C++0x [temp.param]p9:
580 // A default template-argument may be specified for any kind of
581 // template-parameter that is not a template parameter pack.
582 if (DefaultArg && IsParameterPack) {
583 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
584 DefaultArg = ParsedType();
587 // Handle the default argument, if provided.
589 TypeSourceInfo *DefaultTInfo;
590 GetTypeFromParser(DefaultArg, &DefaultTInfo);
592 assert(DefaultTInfo && "expected source information for type");
594 // Check for unexpanded parameter packs.
595 if (DiagnoseUnexpandedParameterPack(Loc, DefaultTInfo,
596 UPPC_DefaultArgument))
599 // Check the template argument itself.
600 if (CheckTemplateArgument(Param, DefaultTInfo)) {
601 Param->setInvalidDecl();
605 Param->setDefaultArgument(DefaultTInfo);
611 /// \brief Check that the type of a non-type template parameter is
614 /// \returns the (possibly-promoted) parameter type if valid;
615 /// otherwise, produces a diagnostic and returns a NULL type.
617 Sema::CheckNonTypeTemplateParameterType(QualType T, SourceLocation Loc) {
618 // We don't allow variably-modified types as the type of non-type template
620 if (T->isVariablyModifiedType()) {
621 Diag(Loc, diag::err_variably_modified_nontype_template_param)
626 // C++ [temp.param]p4:
628 // A non-type template-parameter shall have one of the following
629 // (optionally cv-qualified) types:
631 // -- integral or enumeration type,
632 if (T->isIntegralOrEnumerationType() ||
633 // -- pointer to object or pointer to function,
634 T->isPointerType() ||
635 // -- reference to object or reference to function,
636 T->isReferenceType() ||
637 // -- pointer to member,
638 T->isMemberPointerType() ||
639 // -- std::nullptr_t.
640 T->isNullPtrType() ||
641 // If T is a dependent type, we can't do the check now, so we
642 // assume that it is well-formed.
643 T->isDependentType()) {
644 // C++ [temp.param]p5: The top-level cv-qualifiers on the template-parameter
645 // are ignored when determining its type.
646 return T.getUnqualifiedType();
649 // C++ [temp.param]p8:
651 // A non-type template-parameter of type "array of T" or
652 // "function returning T" is adjusted to be of type "pointer to
653 // T" or "pointer to function returning T", respectively.
654 else if (T->isArrayType() || T->isFunctionType())
655 return Context.getDecayedType(T);
657 Diag(Loc, diag::err_template_nontype_parm_bad_type)
663 Decl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
666 SourceLocation EqualLoc,
668 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
669 QualType T = TInfo->getType();
671 assert(S->isTemplateParamScope() &&
672 "Non-type template parameter not in template parameter scope!");
673 bool Invalid = false;
675 T = CheckNonTypeTemplateParameterType(T, D.getIdentifierLoc());
677 T = Context.IntTy; // Recover with an 'int' type.
681 IdentifierInfo *ParamName = D.getIdentifier();
682 bool IsParameterPack = D.hasEllipsis();
683 NonTypeTemplateParmDecl *Param
684 = NonTypeTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
686 D.getIdentifierLoc(),
687 Depth, Position, ParamName, T,
688 IsParameterPack, TInfo);
689 Param->setAccess(AS_public);
692 Param->setInvalidDecl();
695 maybeDiagnoseTemplateParameterShadow(*this, S, D.getIdentifierLoc(),
698 // Add the template parameter into the current scope.
700 IdResolver.AddDecl(Param);
703 // C++0x [temp.param]p9:
704 // A default template-argument may be specified for any kind of
705 // template-parameter that is not a template parameter pack.
706 if (Default && IsParameterPack) {
707 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
711 // Check the well-formedness of the default template argument, if provided.
713 // Check for unexpanded parameter packs.
714 if (DiagnoseUnexpandedParameterPack(Default, UPPC_DefaultArgument))
717 TemplateArgument Converted;
718 ExprResult DefaultRes =
719 CheckTemplateArgument(Param, Param->getType(), Default, Converted);
720 if (DefaultRes.isInvalid()) {
721 Param->setInvalidDecl();
724 Default = DefaultRes.get();
726 Param->setDefaultArgument(Default);
732 /// ActOnTemplateTemplateParameter - Called when a C++ template template
733 /// parameter (e.g. T in template <template \<typename> class T> class array)
734 /// has been parsed. S is the current scope.
735 Decl *Sema::ActOnTemplateTemplateParameter(Scope* S,
736 SourceLocation TmpLoc,
737 TemplateParameterList *Params,
738 SourceLocation EllipsisLoc,
739 IdentifierInfo *Name,
740 SourceLocation NameLoc,
743 SourceLocation EqualLoc,
744 ParsedTemplateArgument Default) {
745 assert(S->isTemplateParamScope() &&
746 "Template template parameter not in template parameter scope!");
748 // Construct the parameter object.
749 bool IsParameterPack = EllipsisLoc.isValid();
750 TemplateTemplateParmDecl *Param =
751 TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
752 NameLoc.isInvalid()? TmpLoc : NameLoc,
753 Depth, Position, IsParameterPack,
755 Param->setAccess(AS_public);
757 // If the template template parameter has a name, then link the identifier
758 // into the scope and lookup mechanisms.
760 maybeDiagnoseTemplateParameterShadow(*this, S, NameLoc, Name);
763 IdResolver.AddDecl(Param);
766 if (Params->size() == 0) {
767 Diag(Param->getLocation(), diag::err_template_template_parm_no_parms)
768 << SourceRange(Params->getLAngleLoc(), Params->getRAngleLoc());
769 Param->setInvalidDecl();
772 // C++0x [temp.param]p9:
773 // A default template-argument may be specified for any kind of
774 // template-parameter that is not a template parameter pack.
775 if (IsParameterPack && !Default.isInvalid()) {
776 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
777 Default = ParsedTemplateArgument();
780 if (!Default.isInvalid()) {
781 // Check only that we have a template template argument. We don't want to
782 // try to check well-formedness now, because our template template parameter
783 // might have dependent types in its template parameters, which we wouldn't
784 // be able to match now.
786 // If none of the template template parameter's template arguments mention
787 // other template parameters, we could actually perform more checking here.
788 // However, it isn't worth doing.
789 TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default);
790 if (DefaultArg.getArgument().getAsTemplate().isNull()) {
791 Diag(DefaultArg.getLocation(), diag::err_template_arg_not_class_template)
792 << DefaultArg.getSourceRange();
796 // Check for unexpanded parameter packs.
797 if (DiagnoseUnexpandedParameterPack(DefaultArg.getLocation(),
798 DefaultArg.getArgument().getAsTemplate(),
799 UPPC_DefaultArgument))
802 Param->setDefaultArgument(Context, DefaultArg);
808 /// ActOnTemplateParameterList - Builds a TemplateParameterList that
809 /// contains the template parameters in Params/NumParams.
810 TemplateParameterList *
811 Sema::ActOnTemplateParameterList(unsigned Depth,
812 SourceLocation ExportLoc,
813 SourceLocation TemplateLoc,
814 SourceLocation LAngleLoc,
815 Decl **Params, unsigned NumParams,
816 SourceLocation RAngleLoc) {
817 if (ExportLoc.isValid())
818 Diag(ExportLoc, diag::warn_template_export_unsupported);
820 return TemplateParameterList::Create(Context, TemplateLoc, LAngleLoc,
821 (NamedDecl**)Params, NumParams,
825 static void SetNestedNameSpecifier(TagDecl *T, const CXXScopeSpec &SS) {
827 T->setQualifierInfo(SS.getWithLocInContext(T->getASTContext()));
831 Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
832 SourceLocation KWLoc, CXXScopeSpec &SS,
833 IdentifierInfo *Name, SourceLocation NameLoc,
835 TemplateParameterList *TemplateParams,
836 AccessSpecifier AS, SourceLocation ModulePrivateLoc,
837 SourceLocation FriendLoc,
838 unsigned NumOuterTemplateParamLists,
839 TemplateParameterList** OuterTemplateParamLists,
840 SkipBodyInfo *SkipBody) {
841 assert(TemplateParams && TemplateParams->size() > 0 &&
842 "No template parameters");
843 assert(TUK != TUK_Reference && "Can only declare or define class templates");
844 bool Invalid = false;
846 // Check that we can declare a template here.
847 if (CheckTemplateDeclScope(S, TemplateParams))
850 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
851 assert(Kind != TTK_Enum && "can't build template of enumerated type");
853 // There is no such thing as an unnamed class template.
855 Diag(KWLoc, diag::err_template_unnamed_class);
859 // Find any previous declaration with this name. For a friend with no
860 // scope explicitly specified, we only look for tag declarations (per
861 // C++11 [basic.lookup.elab]p2).
862 DeclContext *SemanticContext;
863 LookupResult Previous(*this, Name, NameLoc,
864 (SS.isEmpty() && TUK == TUK_Friend)
865 ? LookupTagName : LookupOrdinaryName,
867 if (SS.isNotEmpty() && !SS.isInvalid()) {
868 SemanticContext = computeDeclContext(SS, true);
869 if (!SemanticContext) {
870 // FIXME: Horrible, horrible hack! We can't currently represent this
871 // in the AST, and historically we have just ignored such friend
872 // class templates, so don't complain here.
873 Diag(NameLoc, TUK == TUK_Friend
874 ? diag::warn_template_qualified_friend_ignored
875 : diag::err_template_qualified_declarator_no_match)
876 << SS.getScopeRep() << SS.getRange();
877 return TUK != TUK_Friend;
880 if (RequireCompleteDeclContext(SS, SemanticContext))
883 // If we're adding a template to a dependent context, we may need to
884 // rebuilding some of the types used within the template parameter list,
885 // now that we know what the current instantiation is.
886 if (SemanticContext->isDependentContext()) {
887 ContextRAII SavedContext(*this, SemanticContext);
888 if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
890 } else if (TUK != TUK_Friend && TUK != TUK_Reference)
891 diagnoseQualifiedDeclaration(SS, SemanticContext, Name, NameLoc);
893 LookupQualifiedName(Previous, SemanticContext);
895 SemanticContext = CurContext;
897 // C++14 [class.mem]p14:
898 // If T is the name of a class, then each of the following shall have a
899 // name different from T:
900 // -- every member template of class T
901 if (TUK != TUK_Friend &&
902 DiagnoseClassNameShadow(SemanticContext,
903 DeclarationNameInfo(Name, NameLoc)))
906 LookupName(Previous, S);
909 if (Previous.isAmbiguous())
912 NamedDecl *PrevDecl = nullptr;
913 if (Previous.begin() != Previous.end())
914 PrevDecl = (*Previous.begin())->getUnderlyingDecl();
916 // If there is a previous declaration with the same name, check
917 // whether this is a valid redeclaration.
918 ClassTemplateDecl *PrevClassTemplate
919 = dyn_cast_or_null<ClassTemplateDecl>(PrevDecl);
921 // We may have found the injected-class-name of a class template,
922 // class template partial specialization, or class template specialization.
923 // In these cases, grab the template that is being defined or specialized.
924 if (!PrevClassTemplate && PrevDecl && isa<CXXRecordDecl>(PrevDecl) &&
925 cast<CXXRecordDecl>(PrevDecl)->isInjectedClassName()) {
926 PrevDecl = cast<CXXRecordDecl>(PrevDecl->getDeclContext());
928 = cast<CXXRecordDecl>(PrevDecl)->getDescribedClassTemplate();
929 if (!PrevClassTemplate && isa<ClassTemplateSpecializationDecl>(PrevDecl)) {
931 = cast<ClassTemplateSpecializationDecl>(PrevDecl)
932 ->getSpecializedTemplate();
936 if (TUK == TUK_Friend) {
937 // C++ [namespace.memdef]p3:
938 // [...] When looking for a prior declaration of a class or a function
939 // declared as a friend, and when the name of the friend class or
940 // function is neither a qualified name nor a template-id, scopes outside
941 // the innermost enclosing namespace scope are not considered.
943 DeclContext *OutermostContext = CurContext;
944 while (!OutermostContext->isFileContext())
945 OutermostContext = OutermostContext->getLookupParent();
948 (OutermostContext->Equals(PrevDecl->getDeclContext()) ||
949 OutermostContext->Encloses(PrevDecl->getDeclContext()))) {
950 SemanticContext = PrevDecl->getDeclContext();
952 // Declarations in outer scopes don't matter. However, the outermost
953 // context we computed is the semantic context for our new
955 PrevDecl = PrevClassTemplate = nullptr;
956 SemanticContext = OutermostContext;
958 // Check that the chosen semantic context doesn't already contain a
959 // declaration of this name as a non-tag type.
960 Previous.clear(LookupOrdinaryName);
961 DeclContext *LookupContext = SemanticContext;
962 while (LookupContext->isTransparentContext())
963 LookupContext = LookupContext->getLookupParent();
964 LookupQualifiedName(Previous, LookupContext);
966 if (Previous.isAmbiguous())
969 if (Previous.begin() != Previous.end())
970 PrevDecl = (*Previous.begin())->getUnderlyingDecl();
973 } else if (PrevDecl &&
974 !isDeclInScope(Previous.getRepresentativeDecl(), SemanticContext,
976 PrevDecl = PrevClassTemplate = nullptr;
978 if (auto *Shadow = dyn_cast_or_null<UsingShadowDecl>(
979 PrevDecl ? Previous.getRepresentativeDecl() : nullptr)) {
981 !(PrevClassTemplate &&
982 PrevClassTemplate->getDeclContext()->getRedeclContext()->Equals(
983 SemanticContext->getRedeclContext()))) {
984 Diag(KWLoc, diag::err_using_decl_conflict_reverse);
985 Diag(Shadow->getTargetDecl()->getLocation(),
986 diag::note_using_decl_target);
987 Diag(Shadow->getUsingDecl()->getLocation(), diag::note_using_decl) << 0;
988 // Recover by ignoring the old declaration.
989 PrevDecl = PrevClassTemplate = nullptr;
993 if (PrevClassTemplate) {
994 // Ensure that the template parameter lists are compatible. Skip this check
995 // for a friend in a dependent context: the template parameter list itself
996 // could be dependent.
997 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
998 !TemplateParameterListsAreEqual(TemplateParams,
999 PrevClassTemplate->getTemplateParameters(),
1004 // C++ [temp.class]p4:
1005 // In a redeclaration, partial specialization, explicit
1006 // specialization or explicit instantiation of a class template,
1007 // the class-key shall agree in kind with the original class
1008 // template declaration (7.1.5.3).
1009 RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl();
1010 if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind,
1011 TUK == TUK_Definition, KWLoc, Name)) {
1012 Diag(KWLoc, diag::err_use_with_wrong_tag)
1014 << FixItHint::CreateReplacement(KWLoc, PrevRecordDecl->getKindName());
1015 Diag(PrevRecordDecl->getLocation(), diag::note_previous_use);
1016 Kind = PrevRecordDecl->getTagKind();
1019 // Check for redefinition of this class template.
1020 if (TUK == TUK_Definition) {
1021 if (TagDecl *Def = PrevRecordDecl->getDefinition()) {
1022 // If we have a prior definition that is not visible, treat this as
1023 // simply making that previous definition visible.
1024 NamedDecl *Hidden = nullptr;
1025 if (SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
1026 SkipBody->ShouldSkip = true;
1027 auto *Tmpl = cast<CXXRecordDecl>(Hidden)->getDescribedClassTemplate();
1028 assert(Tmpl && "original definition of a class template is not a "
1030 makeMergedDefinitionVisible(Hidden, KWLoc);
1031 makeMergedDefinitionVisible(Tmpl, KWLoc);
1035 Diag(NameLoc, diag::err_redefinition) << Name;
1036 Diag(Def->getLocation(), diag::note_previous_definition);
1037 // FIXME: Would it make sense to try to "forget" the previous
1038 // definition, as part of error recovery?
1042 } else if (PrevDecl && PrevDecl->isTemplateParameter()) {
1043 // Maybe we will complain about the shadowed template parameter.
1044 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl);
1045 // Just pretend that we didn't see the previous declaration.
1047 } else if (PrevDecl) {
1049 // A class template shall not have the same name as any other
1050 // template, class, function, object, enumeration, enumerator,
1051 // namespace, or type in the same scope (3.3), except as specified
1053 Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
1054 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1058 // Check the template parameter list of this declaration, possibly
1059 // merging in the template parameter list from the previous class
1060 // template declaration. Skip this check for a friend in a dependent
1061 // context, because the template parameter list might be dependent.
1062 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
1063 CheckTemplateParameterList(
1065 PrevClassTemplate ? PrevClassTemplate->getTemplateParameters()
1067 (SS.isSet() && SemanticContext && SemanticContext->isRecord() &&
1068 SemanticContext->isDependentContext())
1069 ? TPC_ClassTemplateMember
1070 : TUK == TUK_Friend ? TPC_FriendClassTemplate
1071 : TPC_ClassTemplate))
1075 // If the name of the template was qualified, we must be defining the
1076 // template out-of-line.
1077 if (!SS.isInvalid() && !Invalid && !PrevClassTemplate) {
1078 Diag(NameLoc, TUK == TUK_Friend ? diag::err_friend_decl_does_not_match
1079 : diag::err_member_decl_does_not_match)
1080 << Name << SemanticContext << /*IsDefinition*/true << SS.getRange();
1085 CXXRecordDecl *NewClass =
1086 CXXRecordDecl::Create(Context, Kind, SemanticContext, KWLoc, NameLoc, Name,
1088 PrevClassTemplate->getTemplatedDecl() : nullptr,
1089 /*DelayTypeCreation=*/true);
1090 SetNestedNameSpecifier(NewClass, SS);
1091 if (NumOuterTemplateParamLists > 0)
1092 NewClass->setTemplateParameterListsInfo(Context,
1093 NumOuterTemplateParamLists,
1094 OuterTemplateParamLists);
1096 // Add alignment attributes if necessary; these attributes are checked when
1097 // the ASTContext lays out the structure.
1098 if (TUK == TUK_Definition) {
1099 AddAlignmentAttributesForRecord(NewClass);
1100 AddMsStructLayoutForRecord(NewClass);
1103 ClassTemplateDecl *NewTemplate
1104 = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc,
1105 DeclarationName(Name), TemplateParams,
1106 NewClass, PrevClassTemplate);
1107 NewClass->setDescribedClassTemplate(NewTemplate);
1109 if (ModulePrivateLoc.isValid())
1110 NewTemplate->setModulePrivate();
1112 // Build the type for the class template declaration now.
1113 QualType T = NewTemplate->getInjectedClassNameSpecialization();
1114 T = Context.getInjectedClassNameType(NewClass, T);
1115 assert(T->isDependentType() && "Class template type is not dependent?");
1118 // If we are providing an explicit specialization of a member that is a
1119 // class template, make a note of that.
1120 if (PrevClassTemplate &&
1121 PrevClassTemplate->getInstantiatedFromMemberTemplate())
1122 PrevClassTemplate->setMemberSpecialization();
1124 // Set the access specifier.
1125 if (!Invalid && TUK != TUK_Friend && NewTemplate->getDeclContext()->isRecord())
1126 SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS);
1128 // Set the lexical context of these templates
1129 NewClass->setLexicalDeclContext(CurContext);
1130 NewTemplate->setLexicalDeclContext(CurContext);
1132 if (TUK == TUK_Definition)
1133 NewClass->startDefinition();
1136 ProcessDeclAttributeList(S, NewClass, Attr);
1138 if (PrevClassTemplate)
1139 mergeDeclAttributes(NewClass, PrevClassTemplate->getTemplatedDecl());
1141 AddPushedVisibilityAttribute(NewClass);
1143 if (TUK != TUK_Friend) {
1144 // Per C++ [basic.scope.temp]p2, skip the template parameter scopes.
1146 while ((Outer->getFlags() & Scope::TemplateParamScope) != 0)
1147 Outer = Outer->getParent();
1148 PushOnScopeChains(NewTemplate, Outer);
1150 if (PrevClassTemplate && PrevClassTemplate->getAccess() != AS_none) {
1151 NewTemplate->setAccess(PrevClassTemplate->getAccess());
1152 NewClass->setAccess(PrevClassTemplate->getAccess());
1155 NewTemplate->setObjectOfFriendDecl();
1157 // Friend templates are visible in fairly strange ways.
1158 if (!CurContext->isDependentContext()) {
1159 DeclContext *DC = SemanticContext->getRedeclContext();
1160 DC->makeDeclVisibleInContext(NewTemplate);
1161 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
1162 PushOnScopeChains(NewTemplate, EnclosingScope,
1163 /* AddToContext = */ false);
1166 FriendDecl *Friend = FriendDecl::Create(
1167 Context, CurContext, NewClass->getLocation(), NewTemplate, FriendLoc);
1168 Friend->setAccess(AS_public);
1169 CurContext->addDecl(Friend);
1173 NewTemplate->setInvalidDecl();
1174 NewClass->setInvalidDecl();
1177 ActOnDocumentableDecl(NewTemplate);
1182 /// \brief Diagnose the presence of a default template argument on a
1183 /// template parameter, which is ill-formed in certain contexts.
1185 /// \returns true if the default template argument should be dropped.
1186 static bool DiagnoseDefaultTemplateArgument(Sema &S,
1187 Sema::TemplateParamListContext TPC,
1188 SourceLocation ParamLoc,
1189 SourceRange DefArgRange) {
1191 case Sema::TPC_ClassTemplate:
1192 case Sema::TPC_VarTemplate:
1193 case Sema::TPC_TypeAliasTemplate:
1196 case Sema::TPC_FunctionTemplate:
1197 case Sema::TPC_FriendFunctionTemplateDefinition:
1198 // C++ [temp.param]p9:
1199 // A default template-argument shall not be specified in a
1200 // function template declaration or a function template
1202 // If a friend function template declaration specifies a default
1203 // template-argument, that declaration shall be a definition and shall be
1204 // the only declaration of the function template in the translation unit.
1205 // (C++98/03 doesn't have this wording; see DR226).
1206 S.Diag(ParamLoc, S.getLangOpts().CPlusPlus11 ?
1207 diag::warn_cxx98_compat_template_parameter_default_in_function_template
1208 : diag::ext_template_parameter_default_in_function_template)
1212 case Sema::TPC_ClassTemplateMember:
1213 // C++0x [temp.param]p9:
1214 // A default template-argument shall not be specified in the
1215 // template-parameter-lists of the definition of a member of a
1216 // class template that appears outside of the member's class.
1217 S.Diag(ParamLoc, diag::err_template_parameter_default_template_member)
1221 case Sema::TPC_FriendClassTemplate:
1222 case Sema::TPC_FriendFunctionTemplate:
1223 // C++ [temp.param]p9:
1224 // A default template-argument shall not be specified in a
1225 // friend template declaration.
1226 S.Diag(ParamLoc, diag::err_template_parameter_default_friend_template)
1230 // FIXME: C++0x [temp.param]p9 allows default template-arguments
1231 // for friend function templates if there is only a single
1232 // declaration (and it is a definition). Strange!
1235 llvm_unreachable("Invalid TemplateParamListContext!");
1238 /// \brief Check for unexpanded parameter packs within the template parameters
1239 /// of a template template parameter, recursively.
1240 static bool DiagnoseUnexpandedParameterPacks(Sema &S,
1241 TemplateTemplateParmDecl *TTP) {
1242 // A template template parameter which is a parameter pack is also a pack
1244 if (TTP->isParameterPack())
1247 TemplateParameterList *Params = TTP->getTemplateParameters();
1248 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
1249 NamedDecl *P = Params->getParam(I);
1250 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P)) {
1251 if (!NTTP->isParameterPack() &&
1252 S.DiagnoseUnexpandedParameterPack(NTTP->getLocation(),
1253 NTTP->getTypeSourceInfo(),
1254 Sema::UPPC_NonTypeTemplateParameterType))
1260 if (TemplateTemplateParmDecl *InnerTTP
1261 = dyn_cast<TemplateTemplateParmDecl>(P))
1262 if (DiagnoseUnexpandedParameterPacks(S, InnerTTP))
1269 /// \brief Checks the validity of a template parameter list, possibly
1270 /// considering the template parameter list from a previous
1273 /// If an "old" template parameter list is provided, it must be
1274 /// equivalent (per TemplateParameterListsAreEqual) to the "new"
1275 /// template parameter list.
1277 /// \param NewParams Template parameter list for a new template
1278 /// declaration. This template parameter list will be updated with any
1279 /// default arguments that are carried through from the previous
1280 /// template parameter list.
1282 /// \param OldParams If provided, template parameter list from a
1283 /// previous declaration of the same template. Default template
1284 /// arguments will be merged from the old template parameter list to
1285 /// the new template parameter list.
1287 /// \param TPC Describes the context in which we are checking the given
1288 /// template parameter list.
1290 /// \returns true if an error occurred, false otherwise.
1291 bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
1292 TemplateParameterList *OldParams,
1293 TemplateParamListContext TPC) {
1294 bool Invalid = false;
1296 // C++ [temp.param]p10:
1297 // The set of default template-arguments available for use with a
1298 // template declaration or definition is obtained by merging the
1299 // default arguments from the definition (if in scope) and all
1300 // declarations in scope in the same way default function
1301 // arguments are (8.3.6).
1302 bool SawDefaultArgument = false;
1303 SourceLocation PreviousDefaultArgLoc;
1305 // Dummy initialization to avoid warnings.
1306 TemplateParameterList::iterator OldParam = NewParams->end();
1308 OldParam = OldParams->begin();
1310 bool RemoveDefaultArguments = false;
1311 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
1312 NewParamEnd = NewParams->end();
1313 NewParam != NewParamEnd; ++NewParam) {
1314 // Variables used to diagnose redundant default arguments
1315 bool RedundantDefaultArg = false;
1316 SourceLocation OldDefaultLoc;
1317 SourceLocation NewDefaultLoc;
1319 // Variable used to diagnose missing default arguments
1320 bool MissingDefaultArg = false;
1322 // Variable used to diagnose non-final parameter packs
1323 bool SawParameterPack = false;
1325 if (TemplateTypeParmDecl *NewTypeParm
1326 = dyn_cast<TemplateTypeParmDecl>(*NewParam)) {
1327 // Check the presence of a default argument here.
1328 if (NewTypeParm->hasDefaultArgument() &&
1329 DiagnoseDefaultTemplateArgument(*this, TPC,
1330 NewTypeParm->getLocation(),
1331 NewTypeParm->getDefaultArgumentInfo()->getTypeLoc()
1333 NewTypeParm->removeDefaultArgument();
1335 // Merge default arguments for template type parameters.
1336 TemplateTypeParmDecl *OldTypeParm
1337 = OldParams? cast<TemplateTypeParmDecl>(*OldParam) : nullptr;
1338 if (NewTypeParm->isParameterPack()) {
1339 assert(!NewTypeParm->hasDefaultArgument() &&
1340 "Parameter packs can't have a default argument!");
1341 SawParameterPack = true;
1342 } else if (OldTypeParm && hasVisibleDefaultArgument(OldTypeParm) &&
1343 NewTypeParm->hasDefaultArgument()) {
1344 OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc();
1345 NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc();
1346 SawDefaultArgument = true;
1347 RedundantDefaultArg = true;
1348 PreviousDefaultArgLoc = NewDefaultLoc;
1349 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument()) {
1350 // Merge the default argument from the old declaration to the
1352 NewTypeParm->setInheritedDefaultArgument(Context, OldTypeParm);
1353 PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc();
1354 } else if (NewTypeParm->hasDefaultArgument()) {
1355 SawDefaultArgument = true;
1356 PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc();
1357 } else if (SawDefaultArgument)
1358 MissingDefaultArg = true;
1359 } else if (NonTypeTemplateParmDecl *NewNonTypeParm
1360 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) {
1361 // Check for unexpanded parameter packs.
1362 if (!NewNonTypeParm->isParameterPack() &&
1363 DiagnoseUnexpandedParameterPack(NewNonTypeParm->getLocation(),
1364 NewNonTypeParm->getTypeSourceInfo(),
1365 UPPC_NonTypeTemplateParameterType)) {
1370 // Check the presence of a default argument here.
1371 if (NewNonTypeParm->hasDefaultArgument() &&
1372 DiagnoseDefaultTemplateArgument(*this, TPC,
1373 NewNonTypeParm->getLocation(),
1374 NewNonTypeParm->getDefaultArgument()->getSourceRange())) {
1375 NewNonTypeParm->removeDefaultArgument();
1378 // Merge default arguments for non-type template parameters
1379 NonTypeTemplateParmDecl *OldNonTypeParm
1380 = OldParams? cast<NonTypeTemplateParmDecl>(*OldParam) : nullptr;
1381 if (NewNonTypeParm->isParameterPack()) {
1382 assert(!NewNonTypeParm->hasDefaultArgument() &&
1383 "Parameter packs can't have a default argument!");
1384 if (!NewNonTypeParm->isPackExpansion())
1385 SawParameterPack = true;
1386 } else if (OldNonTypeParm && hasVisibleDefaultArgument(OldNonTypeParm) &&
1387 NewNonTypeParm->hasDefaultArgument()) {
1388 OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc();
1389 NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc();
1390 SawDefaultArgument = true;
1391 RedundantDefaultArg = true;
1392 PreviousDefaultArgLoc = NewDefaultLoc;
1393 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument()) {
1394 // Merge the default argument from the old declaration to the
1396 NewNonTypeParm->setInheritedDefaultArgument(Context, OldNonTypeParm);
1397 PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc();
1398 } else if (NewNonTypeParm->hasDefaultArgument()) {
1399 SawDefaultArgument = true;
1400 PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc();
1401 } else if (SawDefaultArgument)
1402 MissingDefaultArg = true;
1404 TemplateTemplateParmDecl *NewTemplateParm
1405 = cast<TemplateTemplateParmDecl>(*NewParam);
1407 // Check for unexpanded parameter packs, recursively.
1408 if (::DiagnoseUnexpandedParameterPacks(*this, NewTemplateParm)) {
1413 // Check the presence of a default argument here.
1414 if (NewTemplateParm->hasDefaultArgument() &&
1415 DiagnoseDefaultTemplateArgument(*this, TPC,
1416 NewTemplateParm->getLocation(),
1417 NewTemplateParm->getDefaultArgument().getSourceRange()))
1418 NewTemplateParm->removeDefaultArgument();
1420 // Merge default arguments for template template parameters
1421 TemplateTemplateParmDecl *OldTemplateParm
1422 = OldParams? cast<TemplateTemplateParmDecl>(*OldParam) : nullptr;
1423 if (NewTemplateParm->isParameterPack()) {
1424 assert(!NewTemplateParm->hasDefaultArgument() &&
1425 "Parameter packs can't have a default argument!");
1426 if (!NewTemplateParm->isPackExpansion())
1427 SawParameterPack = true;
1428 } else if (OldTemplateParm &&
1429 hasVisibleDefaultArgument(OldTemplateParm) &&
1430 NewTemplateParm->hasDefaultArgument()) {
1431 OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation();
1432 NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation();
1433 SawDefaultArgument = true;
1434 RedundantDefaultArg = true;
1435 PreviousDefaultArgLoc = NewDefaultLoc;
1436 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument()) {
1437 // Merge the default argument from the old declaration to the
1439 NewTemplateParm->setInheritedDefaultArgument(Context, OldTemplateParm);
1440 PreviousDefaultArgLoc
1441 = OldTemplateParm->getDefaultArgument().getLocation();
1442 } else if (NewTemplateParm->hasDefaultArgument()) {
1443 SawDefaultArgument = true;
1444 PreviousDefaultArgLoc
1445 = NewTemplateParm->getDefaultArgument().getLocation();
1446 } else if (SawDefaultArgument)
1447 MissingDefaultArg = true;
1450 // C++11 [temp.param]p11:
1451 // If a template parameter of a primary class template or alias template
1452 // is a template parameter pack, it shall be the last template parameter.
1453 if (SawParameterPack && (NewParam + 1) != NewParamEnd &&
1454 (TPC == TPC_ClassTemplate || TPC == TPC_VarTemplate ||
1455 TPC == TPC_TypeAliasTemplate)) {
1456 Diag((*NewParam)->getLocation(),
1457 diag::err_template_param_pack_must_be_last_template_parameter);
1461 if (RedundantDefaultArg) {
1462 // C++ [temp.param]p12:
1463 // A template-parameter shall not be given default arguments
1464 // by two different declarations in the same scope.
1465 Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition);
1466 Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg);
1468 } else if (MissingDefaultArg && TPC != TPC_FunctionTemplate) {
1469 // C++ [temp.param]p11:
1470 // If a template-parameter of a class template has a default
1471 // template-argument, each subsequent template-parameter shall either
1472 // have a default template-argument supplied or be a template parameter
1474 Diag((*NewParam)->getLocation(),
1475 diag::err_template_param_default_arg_missing);
1476 Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg);
1478 RemoveDefaultArguments = true;
1481 // If we have an old template parameter list that we're merging
1482 // in, move on to the next parameter.
1487 // We were missing some default arguments at the end of the list, so remove
1488 // all of the default arguments.
1489 if (RemoveDefaultArguments) {
1490 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
1491 NewParamEnd = NewParams->end();
1492 NewParam != NewParamEnd; ++NewParam) {
1493 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*NewParam))
1494 TTP->removeDefaultArgument();
1495 else if (NonTypeTemplateParmDecl *NTTP
1496 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam))
1497 NTTP->removeDefaultArgument();
1499 cast<TemplateTemplateParmDecl>(*NewParam)->removeDefaultArgument();
1508 /// A class which looks for a use of a certain level of template
1510 struct DependencyChecker : RecursiveASTVisitor<DependencyChecker> {
1511 typedef RecursiveASTVisitor<DependencyChecker> super;
1515 SourceLocation MatchLoc;
1517 DependencyChecker(unsigned Depth) : Depth(Depth), Match(false) {}
1519 DependencyChecker(TemplateParameterList *Params) : Match(false) {
1520 NamedDecl *ND = Params->getParam(0);
1521 if (TemplateTypeParmDecl *PD = dyn_cast<TemplateTypeParmDecl>(ND)) {
1522 Depth = PD->getDepth();
1523 } else if (NonTypeTemplateParmDecl *PD =
1524 dyn_cast<NonTypeTemplateParmDecl>(ND)) {
1525 Depth = PD->getDepth();
1527 Depth = cast<TemplateTemplateParmDecl>(ND)->getDepth();
1531 bool Matches(unsigned ParmDepth, SourceLocation Loc = SourceLocation()) {
1532 if (ParmDepth >= Depth) {
1540 bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
1541 return !Matches(TL.getTypePtr()->getDepth(), TL.getNameLoc());
1544 bool VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
1545 return !Matches(T->getDepth());
1548 bool TraverseTemplateName(TemplateName N) {
1549 if (TemplateTemplateParmDecl *PD =
1550 dyn_cast_or_null<TemplateTemplateParmDecl>(N.getAsTemplateDecl()))
1551 if (Matches(PD->getDepth()))
1553 return super::TraverseTemplateName(N);
1556 bool VisitDeclRefExpr(DeclRefExpr *E) {
1557 if (NonTypeTemplateParmDecl *PD =
1558 dyn_cast<NonTypeTemplateParmDecl>(E->getDecl()))
1559 if (Matches(PD->getDepth(), E->getExprLoc()))
1561 return super::VisitDeclRefExpr(E);
1564 bool VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *T) {
1565 return TraverseType(T->getReplacementType());
1569 VisitSubstTemplateTypeParmPackType(const SubstTemplateTypeParmPackType *T) {
1570 return TraverseTemplateArgument(T->getArgumentPack());
1573 bool TraverseInjectedClassNameType(const InjectedClassNameType *T) {
1574 return TraverseType(T->getInjectedSpecializationType());
1579 /// Determines whether a given type depends on the given parameter
1582 DependsOnTemplateParameters(QualType T, TemplateParameterList *Params) {
1583 DependencyChecker Checker(Params);
1584 Checker.TraverseType(T);
1585 return Checker.Match;
1588 // Find the source range corresponding to the named type in the given
1589 // nested-name-specifier, if any.
1590 static SourceRange getRangeOfTypeInNestedNameSpecifier(ASTContext &Context,
1592 const CXXScopeSpec &SS) {
1593 NestedNameSpecifierLoc NNSLoc(SS.getScopeRep(), SS.location_data());
1594 while (NestedNameSpecifier *NNS = NNSLoc.getNestedNameSpecifier()) {
1595 if (const Type *CurType = NNS->getAsType()) {
1596 if (Context.hasSameUnqualifiedType(T, QualType(CurType, 0)))
1597 return NNSLoc.getTypeLoc().getSourceRange();
1601 NNSLoc = NNSLoc.getPrefix();
1604 return SourceRange();
1607 /// \brief Match the given template parameter lists to the given scope
1608 /// specifier, returning the template parameter list that applies to the
1611 /// \param DeclStartLoc the start of the declaration that has a scope
1612 /// specifier or a template parameter list.
1614 /// \param DeclLoc The location of the declaration itself.
1616 /// \param SS the scope specifier that will be matched to the given template
1617 /// parameter lists. This scope specifier precedes a qualified name that is
1620 /// \param TemplateId The template-id following the scope specifier, if there
1621 /// is one. Used to check for a missing 'template<>'.
1623 /// \param ParamLists the template parameter lists, from the outermost to the
1624 /// innermost template parameter lists.
1626 /// \param IsFriend Whether to apply the slightly different rules for
1627 /// matching template parameters to scope specifiers in friend
1630 /// \param IsExplicitSpecialization will be set true if the entity being
1631 /// declared is an explicit specialization, false otherwise.
1633 /// \returns the template parameter list, if any, that corresponds to the
1634 /// name that is preceded by the scope specifier @p SS. This template
1635 /// parameter list may have template parameters (if we're declaring a
1636 /// template) or may have no template parameters (if we're declaring a
1637 /// template specialization), or may be NULL (if what we're declaring isn't
1638 /// itself a template).
1639 TemplateParameterList *Sema::MatchTemplateParametersToScopeSpecifier(
1640 SourceLocation DeclStartLoc, SourceLocation DeclLoc, const CXXScopeSpec &SS,
1641 TemplateIdAnnotation *TemplateId,
1642 ArrayRef<TemplateParameterList *> ParamLists, bool IsFriend,
1643 bool &IsExplicitSpecialization, bool &Invalid) {
1644 IsExplicitSpecialization = false;
1647 // The sequence of nested types to which we will match up the template
1648 // parameter lists. We first build this list by starting with the type named
1649 // by the nested-name-specifier and walking out until we run out of types.
1650 SmallVector<QualType, 4> NestedTypes;
1652 if (SS.getScopeRep()) {
1653 if (CXXRecordDecl *Record
1654 = dyn_cast_or_null<CXXRecordDecl>(computeDeclContext(SS, true)))
1655 T = Context.getTypeDeclType(Record);
1657 T = QualType(SS.getScopeRep()->getAsType(), 0);
1660 // If we found an explicit specialization that prevents us from needing
1661 // 'template<>' headers, this will be set to the location of that
1662 // explicit specialization.
1663 SourceLocation ExplicitSpecLoc;
1665 while (!T.isNull()) {
1666 NestedTypes.push_back(T);
1668 // Retrieve the parent of a record type.
1669 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
1670 // If this type is an explicit specialization, we're done.
1671 if (ClassTemplateSpecializationDecl *Spec
1672 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
1673 if (!isa<ClassTemplatePartialSpecializationDecl>(Spec) &&
1674 Spec->getSpecializationKind() == TSK_ExplicitSpecialization) {
1675 ExplicitSpecLoc = Spec->getLocation();
1678 } else if (Record->getTemplateSpecializationKind()
1679 == TSK_ExplicitSpecialization) {
1680 ExplicitSpecLoc = Record->getLocation();
1684 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Record->getParent()))
1685 T = Context.getTypeDeclType(Parent);
1691 if (const TemplateSpecializationType *TST
1692 = T->getAs<TemplateSpecializationType>()) {
1693 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
1694 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Template->getDeclContext()))
1695 T = Context.getTypeDeclType(Parent);
1702 // Look one step prior in a dependent template specialization type.
1703 if (const DependentTemplateSpecializationType *DependentTST
1704 = T->getAs<DependentTemplateSpecializationType>()) {
1705 if (NestedNameSpecifier *NNS = DependentTST->getQualifier())
1706 T = QualType(NNS->getAsType(), 0);
1712 // Look one step prior in a dependent name type.
1713 if (const DependentNameType *DependentName = T->getAs<DependentNameType>()){
1714 if (NestedNameSpecifier *NNS = DependentName->getQualifier())
1715 T = QualType(NNS->getAsType(), 0);
1721 // Retrieve the parent of an enumeration type.
1722 if (const EnumType *EnumT = T->getAs<EnumType>()) {
1723 // FIXME: Forward-declared enums require a TSK_ExplicitSpecialization
1725 EnumDecl *Enum = EnumT->getDecl();
1727 // Get to the parent type.
1728 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Enum->getParent()))
1729 T = Context.getTypeDeclType(Parent);
1737 // Reverse the nested types list, since we want to traverse from the outermost
1738 // to the innermost while checking template-parameter-lists.
1739 std::reverse(NestedTypes.begin(), NestedTypes.end());
1741 // C++0x [temp.expl.spec]p17:
1742 // A member or a member template may be nested within many
1743 // enclosing class templates. In an explicit specialization for
1744 // such a member, the member declaration shall be preceded by a
1745 // template<> for each enclosing class template that is
1746 // explicitly specialized.
1747 bool SawNonEmptyTemplateParameterList = false;
1749 auto CheckExplicitSpecialization = [&](SourceRange Range, bool Recovery) {
1750 if (SawNonEmptyTemplateParameterList) {
1751 Diag(DeclLoc, diag::err_specialize_member_of_template)
1752 << !Recovery << Range;
1754 IsExplicitSpecialization = false;
1761 auto DiagnoseMissingExplicitSpecialization = [&] (SourceRange Range) {
1762 // Check that we can have an explicit specialization here.
1763 if (CheckExplicitSpecialization(Range, true))
1766 // We don't have a template header, but we should.
1767 SourceLocation ExpectedTemplateLoc;
1768 if (!ParamLists.empty())
1769 ExpectedTemplateLoc = ParamLists[0]->getTemplateLoc();
1771 ExpectedTemplateLoc = DeclStartLoc;
1773 Diag(DeclLoc, diag::err_template_spec_needs_header)
1775 << FixItHint::CreateInsertion(ExpectedTemplateLoc, "template<> ");
1779 unsigned ParamIdx = 0;
1780 for (unsigned TypeIdx = 0, NumTypes = NestedTypes.size(); TypeIdx != NumTypes;
1782 T = NestedTypes[TypeIdx];
1784 // Whether we expect a 'template<>' header.
1785 bool NeedEmptyTemplateHeader = false;
1787 // Whether we expect a template header with parameters.
1788 bool NeedNonemptyTemplateHeader = false;
1790 // For a dependent type, the set of template parameters that we
1792 TemplateParameterList *ExpectedTemplateParams = nullptr;
1794 // C++0x [temp.expl.spec]p15:
1795 // A member or a member template may be nested within many enclosing
1796 // class templates. In an explicit specialization for such a member, the
1797 // member declaration shall be preceded by a template<> for each
1798 // enclosing class template that is explicitly specialized.
1799 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
1800 if (ClassTemplatePartialSpecializationDecl *Partial
1801 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
1802 ExpectedTemplateParams = Partial->getTemplateParameters();
1803 NeedNonemptyTemplateHeader = true;
1804 } else if (Record->isDependentType()) {
1805 if (Record->getDescribedClassTemplate()) {
1806 ExpectedTemplateParams = Record->getDescribedClassTemplate()
1807 ->getTemplateParameters();
1808 NeedNonemptyTemplateHeader = true;
1810 } else if (ClassTemplateSpecializationDecl *Spec
1811 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
1812 // C++0x [temp.expl.spec]p4:
1813 // Members of an explicitly specialized class template are defined
1814 // in the same manner as members of normal classes, and not using
1815 // the template<> syntax.
1816 if (Spec->getSpecializationKind() != TSK_ExplicitSpecialization)
1817 NeedEmptyTemplateHeader = true;
1820 } else if (Record->getTemplateSpecializationKind()) {
1821 if (Record->getTemplateSpecializationKind()
1822 != TSK_ExplicitSpecialization &&
1823 TypeIdx == NumTypes - 1)
1824 IsExplicitSpecialization = true;
1828 } else if (const TemplateSpecializationType *TST
1829 = T->getAs<TemplateSpecializationType>()) {
1830 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
1831 ExpectedTemplateParams = Template->getTemplateParameters();
1832 NeedNonemptyTemplateHeader = true;
1834 } else if (T->getAs<DependentTemplateSpecializationType>()) {
1835 // FIXME: We actually could/should check the template arguments here
1836 // against the corresponding template parameter list.
1837 NeedNonemptyTemplateHeader = false;
1840 // C++ [temp.expl.spec]p16:
1841 // In an explicit specialization declaration for a member of a class
1842 // template or a member template that ap- pears in namespace scope, the
1843 // member template and some of its enclosing class templates may remain
1844 // unspecialized, except that the declaration shall not explicitly
1845 // specialize a class member template if its en- closing class templates
1846 // are not explicitly specialized as well.
1847 if (ParamIdx < ParamLists.size()) {
1848 if (ParamLists[ParamIdx]->size() == 0) {
1849 if (CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
1853 SawNonEmptyTemplateParameterList = true;
1856 if (NeedEmptyTemplateHeader) {
1857 // If we're on the last of the types, and we need a 'template<>' header
1858 // here, then it's an explicit specialization.
1859 if (TypeIdx == NumTypes - 1)
1860 IsExplicitSpecialization = true;
1862 if (ParamIdx < ParamLists.size()) {
1863 if (ParamLists[ParamIdx]->size() > 0) {
1864 // The header has template parameters when it shouldn't. Complain.
1865 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
1866 diag::err_template_param_list_matches_nontemplate)
1868 << SourceRange(ParamLists[ParamIdx]->getLAngleLoc(),
1869 ParamLists[ParamIdx]->getRAngleLoc())
1870 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
1875 // Consume this template header.
1881 if (DiagnoseMissingExplicitSpecialization(
1882 getRangeOfTypeInNestedNameSpecifier(Context, T, SS)))
1888 if (NeedNonemptyTemplateHeader) {
1889 // In friend declarations we can have template-ids which don't
1890 // depend on the corresponding template parameter lists. But
1891 // assume that empty parameter lists are supposed to match this
1893 if (IsFriend && T->isDependentType()) {
1894 if (ParamIdx < ParamLists.size() &&
1895 DependsOnTemplateParameters(T, ParamLists[ParamIdx]))
1896 ExpectedTemplateParams = nullptr;
1901 if (ParamIdx < ParamLists.size()) {
1902 // Check the template parameter list, if we can.
1903 if (ExpectedTemplateParams &&
1904 !TemplateParameterListsAreEqual(ParamLists[ParamIdx],
1905 ExpectedTemplateParams,
1906 true, TPL_TemplateMatch))
1910 CheckTemplateParameterList(ParamLists[ParamIdx], nullptr,
1911 TPC_ClassTemplateMember))
1918 Diag(DeclLoc, diag::err_template_spec_needs_template_parameters)
1920 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
1926 // If there were at least as many template-ids as there were template
1927 // parameter lists, then there are no template parameter lists remaining for
1928 // the declaration itself.
1929 if (ParamIdx >= ParamLists.size()) {
1930 if (TemplateId && !IsFriend) {
1931 // We don't have a template header for the declaration itself, but we
1933 IsExplicitSpecialization = true;
1934 DiagnoseMissingExplicitSpecialization(SourceRange(TemplateId->LAngleLoc,
1935 TemplateId->RAngleLoc));
1937 // Fabricate an empty template parameter list for the invented header.
1938 return TemplateParameterList::Create(Context, SourceLocation(),
1939 SourceLocation(), nullptr, 0,
1946 // If there were too many template parameter lists, complain about that now.
1947 if (ParamIdx < ParamLists.size() - 1) {
1948 bool HasAnyExplicitSpecHeader = false;
1949 bool AllExplicitSpecHeaders = true;
1950 for (unsigned I = ParamIdx, E = ParamLists.size() - 1; I != E; ++I) {
1951 if (ParamLists[I]->size() == 0)
1952 HasAnyExplicitSpecHeader = true;
1954 AllExplicitSpecHeaders = false;
1957 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
1958 AllExplicitSpecHeaders ? diag::warn_template_spec_extra_headers
1959 : diag::err_template_spec_extra_headers)
1960 << SourceRange(ParamLists[ParamIdx]->getTemplateLoc(),
1961 ParamLists[ParamLists.size() - 2]->getRAngleLoc());
1963 // If there was a specialization somewhere, such that 'template<>' is
1964 // not required, and there were any 'template<>' headers, note where the
1965 // specialization occurred.
1966 if (ExplicitSpecLoc.isValid() && HasAnyExplicitSpecHeader)
1967 Diag(ExplicitSpecLoc,
1968 diag::note_explicit_template_spec_does_not_need_header)
1969 << NestedTypes.back();
1971 // We have a template parameter list with no corresponding scope, which
1972 // means that the resulting template declaration can't be instantiated
1973 // properly (we'll end up with dependent nodes when we shouldn't).
1974 if (!AllExplicitSpecHeaders)
1978 // C++ [temp.expl.spec]p16:
1979 // In an explicit specialization declaration for a member of a class
1980 // template or a member template that ap- pears in namespace scope, the
1981 // member template and some of its enclosing class templates may remain
1982 // unspecialized, except that the declaration shall not explicitly
1983 // specialize a class member template if its en- closing class templates
1984 // are not explicitly specialized as well.
1985 if (ParamLists.back()->size() == 0 &&
1986 CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
1990 // Return the last template parameter list, which corresponds to the
1991 // entity being declared.
1992 return ParamLists.back();
1995 void Sema::NoteAllFoundTemplates(TemplateName Name) {
1996 if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
1997 Diag(Template->getLocation(), diag::note_template_declared_here)
1998 << (isa<FunctionTemplateDecl>(Template)
2000 : isa<ClassTemplateDecl>(Template)
2002 : isa<VarTemplateDecl>(Template)
2004 : isa<TypeAliasTemplateDecl>(Template) ? 3 : 4)
2005 << Template->getDeclName();
2009 if (OverloadedTemplateStorage *OST = Name.getAsOverloadedTemplate()) {
2010 for (OverloadedTemplateStorage::iterator I = OST->begin(),
2013 Diag((*I)->getLocation(), diag::note_template_declared_here)
2014 << 0 << (*I)->getDeclName();
2020 QualType Sema::CheckTemplateIdType(TemplateName Name,
2021 SourceLocation TemplateLoc,
2022 TemplateArgumentListInfo &TemplateArgs) {
2023 DependentTemplateName *DTN
2024 = Name.getUnderlying().getAsDependentTemplateName();
2025 if (DTN && DTN->isIdentifier())
2026 // When building a template-id where the template-name is dependent,
2027 // assume the template is a type template. Either our assumption is
2028 // correct, or the code is ill-formed and will be diagnosed when the
2029 // dependent name is substituted.
2030 return Context.getDependentTemplateSpecializationType(ETK_None,
2031 DTN->getQualifier(),
2032 DTN->getIdentifier(),
2035 TemplateDecl *Template = Name.getAsTemplateDecl();
2036 if (!Template || isa<FunctionTemplateDecl>(Template) ||
2037 isa<VarTemplateDecl>(Template)) {
2038 // We might have a substituted template template parameter pack. If so,
2039 // build a template specialization type for it.
2040 if (Name.getAsSubstTemplateTemplateParmPack())
2041 return Context.getTemplateSpecializationType(Name, TemplateArgs);
2043 Diag(TemplateLoc, diag::err_template_id_not_a_type)
2045 NoteAllFoundTemplates(Name);
2049 // Check that the template argument list is well-formed for this
2051 SmallVector<TemplateArgument, 4> Converted;
2052 if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs,
2058 bool InstantiationDependent = false;
2059 if (TypeAliasTemplateDecl *AliasTemplate =
2060 dyn_cast<TypeAliasTemplateDecl>(Template)) {
2061 // Find the canonical type for this type alias template specialization.
2062 TypeAliasDecl *Pattern = AliasTemplate->getTemplatedDecl();
2063 if (Pattern->isInvalidDecl())
2066 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
2067 Converted.data(), Converted.size());
2069 // Only substitute for the innermost template argument list.
2070 MultiLevelTemplateArgumentList TemplateArgLists;
2071 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
2072 unsigned Depth = AliasTemplate->getTemplateParameters()->getDepth();
2073 for (unsigned I = 0; I < Depth; ++I)
2074 TemplateArgLists.addOuterTemplateArguments(None);
2076 LocalInstantiationScope Scope(*this);
2077 InstantiatingTemplate Inst(*this, TemplateLoc, Template);
2078 if (Inst.isInvalid())
2081 CanonType = SubstType(Pattern->getUnderlyingType(),
2082 TemplateArgLists, AliasTemplate->getLocation(),
2083 AliasTemplate->getDeclName());
2084 if (CanonType.isNull())
2086 } else if (Name.isDependent() ||
2087 TemplateSpecializationType::anyDependentTemplateArguments(
2088 TemplateArgs, InstantiationDependent)) {
2089 // This class template specialization is a dependent
2090 // type. Therefore, its canonical type is another class template
2091 // specialization type that contains all of the converted
2092 // arguments in canonical form. This ensures that, e.g., A<T> and
2093 // A<T, T> have identical types when A is declared as:
2095 // template<typename T, typename U = T> struct A;
2096 TemplateName CanonName = Context.getCanonicalTemplateName(Name);
2097 CanonType = Context.getTemplateSpecializationType(CanonName,
2101 // FIXME: CanonType is not actually the canonical type, and unfortunately
2102 // it is a TemplateSpecializationType that we will never use again.
2103 // In the future, we need to teach getTemplateSpecializationType to only
2104 // build the canonical type and return that to us.
2105 CanonType = Context.getCanonicalType(CanonType);
2107 // This might work out to be a current instantiation, in which
2108 // case the canonical type needs to be the InjectedClassNameType.
2110 // TODO: in theory this could be a simple hashtable lookup; most
2111 // changes to CurContext don't change the set of current
2113 if (isa<ClassTemplateDecl>(Template)) {
2114 for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) {
2115 // If we get out to a namespace, we're done.
2116 if (Ctx->isFileContext()) break;
2118 // If this isn't a record, keep looking.
2119 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx);
2120 if (!Record) continue;
2122 // Look for one of the two cases with InjectedClassNameTypes
2123 // and check whether it's the same template.
2124 if (!isa<ClassTemplatePartialSpecializationDecl>(Record) &&
2125 !Record->getDescribedClassTemplate())
2128 // Fetch the injected class name type and check whether its
2129 // injected type is equal to the type we just built.
2130 QualType ICNT = Context.getTypeDeclType(Record);
2131 QualType Injected = cast<InjectedClassNameType>(ICNT)
2132 ->getInjectedSpecializationType();
2134 if (CanonType != Injected->getCanonicalTypeInternal())
2137 // If so, the canonical type of this TST is the injected
2138 // class name type of the record we just found.
2139 assert(ICNT.isCanonical());
2144 } else if (ClassTemplateDecl *ClassTemplate
2145 = dyn_cast<ClassTemplateDecl>(Template)) {
2146 // Find the class template specialization declaration that
2147 // corresponds to these arguments.
2148 void *InsertPos = nullptr;
2149 ClassTemplateSpecializationDecl *Decl
2150 = ClassTemplate->findSpecialization(Converted, InsertPos);
2152 // This is the first time we have referenced this class template
2153 // specialization. Create the canonical declaration and add it to
2154 // the set of specializations.
2155 Decl = ClassTemplateSpecializationDecl::Create(Context,
2156 ClassTemplate->getTemplatedDecl()->getTagKind(),
2157 ClassTemplate->getDeclContext(),
2158 ClassTemplate->getTemplatedDecl()->getLocStart(),
2159 ClassTemplate->getLocation(),
2162 Converted.size(), nullptr);
2163 ClassTemplate->AddSpecialization(Decl, InsertPos);
2164 if (ClassTemplate->isOutOfLine())
2165 Decl->setLexicalDeclContext(ClassTemplate->getLexicalDeclContext());
2168 // Diagnose uses of this specialization.
2169 (void)DiagnoseUseOfDecl(Decl, TemplateLoc);
2171 CanonType = Context.getTypeDeclType(Decl);
2172 assert(isa<RecordType>(CanonType) &&
2173 "type of non-dependent specialization is not a RecordType");
2176 // Build the fully-sugared type for this class template
2177 // specialization, which refers back to the class template
2178 // specialization we created or found.
2179 return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType);
2183 Sema::ActOnTemplateIdType(CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
2184 TemplateTy TemplateD, SourceLocation TemplateLoc,
2185 SourceLocation LAngleLoc,
2186 ASTTemplateArgsPtr TemplateArgsIn,
2187 SourceLocation RAngleLoc,
2188 bool IsCtorOrDtorName) {
2192 TemplateName Template = TemplateD.get();
2194 // Translate the parser's template argument list in our AST format.
2195 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
2196 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
2198 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
2200 = Context.getDependentTemplateSpecializationType(ETK_None,
2201 DTN->getQualifier(),
2202 DTN->getIdentifier(),
2204 // Build type-source information.
2206 DependentTemplateSpecializationTypeLoc SpecTL
2207 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
2208 SpecTL.setElaboratedKeywordLoc(SourceLocation());
2209 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
2210 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2211 SpecTL.setTemplateNameLoc(TemplateLoc);
2212 SpecTL.setLAngleLoc(LAngleLoc);
2213 SpecTL.setRAngleLoc(RAngleLoc);
2214 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
2215 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
2216 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
2219 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
2221 if (Result.isNull())
2224 // Build type-source information.
2226 TemplateSpecializationTypeLoc SpecTL
2227 = TLB.push<TemplateSpecializationTypeLoc>(Result);
2228 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2229 SpecTL.setTemplateNameLoc(TemplateLoc);
2230 SpecTL.setLAngleLoc(LAngleLoc);
2231 SpecTL.setRAngleLoc(RAngleLoc);
2232 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
2233 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
2235 // NOTE: avoid constructing an ElaboratedTypeLoc if this is a
2236 // constructor or destructor name (in such a case, the scope specifier
2237 // will be attached to the enclosing Decl or Expr node).
2238 if (SS.isNotEmpty() && !IsCtorOrDtorName) {
2239 // Create an elaborated-type-specifier containing the nested-name-specifier.
2240 Result = Context.getElaboratedType(ETK_None, SS.getScopeRep(), Result);
2241 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
2242 ElabTL.setElaboratedKeywordLoc(SourceLocation());
2243 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
2246 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
2249 TypeResult Sema::ActOnTagTemplateIdType(TagUseKind TUK,
2250 TypeSpecifierType TagSpec,
2251 SourceLocation TagLoc,
2253 SourceLocation TemplateKWLoc,
2254 TemplateTy TemplateD,
2255 SourceLocation TemplateLoc,
2256 SourceLocation LAngleLoc,
2257 ASTTemplateArgsPtr TemplateArgsIn,
2258 SourceLocation RAngleLoc) {
2259 TemplateName Template = TemplateD.get();
2261 // Translate the parser's template argument list in our AST format.
2262 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
2263 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
2265 // Determine the tag kind
2266 TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
2267 ElaboratedTypeKeyword Keyword
2268 = TypeWithKeyword::getKeywordForTagTypeKind(TagKind);
2270 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
2271 QualType T = Context.getDependentTemplateSpecializationType(Keyword,
2272 DTN->getQualifier(),
2273 DTN->getIdentifier(),
2276 // Build type-source information.
2278 DependentTemplateSpecializationTypeLoc SpecTL
2279 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
2280 SpecTL.setElaboratedKeywordLoc(TagLoc);
2281 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
2282 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2283 SpecTL.setTemplateNameLoc(TemplateLoc);
2284 SpecTL.setLAngleLoc(LAngleLoc);
2285 SpecTL.setRAngleLoc(RAngleLoc);
2286 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
2287 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
2288 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
2291 if (TypeAliasTemplateDecl *TAT =
2292 dyn_cast_or_null<TypeAliasTemplateDecl>(Template.getAsTemplateDecl())) {
2293 // C++0x [dcl.type.elab]p2:
2294 // If the identifier resolves to a typedef-name or the simple-template-id
2295 // resolves to an alias template specialization, the
2296 // elaborated-type-specifier is ill-formed.
2297 Diag(TemplateLoc, diag::err_tag_reference_non_tag) << 4;
2298 Diag(TAT->getLocation(), diag::note_declared_at);
2301 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
2302 if (Result.isNull())
2303 return TypeResult(true);
2305 // Check the tag kind
2306 if (const RecordType *RT = Result->getAs<RecordType>()) {
2307 RecordDecl *D = RT->getDecl();
2309 IdentifierInfo *Id = D->getIdentifier();
2310 assert(Id && "templated class must have an identifier");
2312 if (!isAcceptableTagRedeclaration(D, TagKind, TUK == TUK_Definition,
2314 Diag(TagLoc, diag::err_use_with_wrong_tag)
2316 << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName());
2317 Diag(D->getLocation(), diag::note_previous_use);
2321 // Provide source-location information for the template specialization.
2323 TemplateSpecializationTypeLoc SpecTL
2324 = TLB.push<TemplateSpecializationTypeLoc>(Result);
2325 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2326 SpecTL.setTemplateNameLoc(TemplateLoc);
2327 SpecTL.setLAngleLoc(LAngleLoc);
2328 SpecTL.setRAngleLoc(RAngleLoc);
2329 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
2330 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
2332 // Construct an elaborated type containing the nested-name-specifier (if any)
2334 Result = Context.getElaboratedType(Keyword, SS.getScopeRep(), Result);
2335 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
2336 ElabTL.setElaboratedKeywordLoc(TagLoc);
2337 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
2338 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
2341 static bool CheckTemplatePartialSpecializationArgs(
2342 Sema &S, SourceLocation NameLoc, TemplateParameterList *TemplateParams,
2343 unsigned ExplicitArgs, SmallVectorImpl<TemplateArgument> &TemplateArgs);
2345 static bool CheckTemplateSpecializationScope(Sema &S, NamedDecl *Specialized,
2346 NamedDecl *PrevDecl,
2348 bool IsPartialSpecialization);
2350 static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D);
2352 static bool isTemplateArgumentTemplateParameter(
2353 const TemplateArgument &Arg, unsigned Depth, unsigned Index) {
2354 switch (Arg.getKind()) {
2355 case TemplateArgument::Null:
2356 case TemplateArgument::NullPtr:
2357 case TemplateArgument::Integral:
2358 case TemplateArgument::Declaration:
2359 case TemplateArgument::Pack:
2360 case TemplateArgument::TemplateExpansion:
2363 case TemplateArgument::Type: {
2364 QualType Type = Arg.getAsType();
2365 const TemplateTypeParmType *TPT =
2366 Arg.getAsType()->getAs<TemplateTypeParmType>();
2367 return TPT && !Type.hasQualifiers() &&
2368 TPT->getDepth() == Depth && TPT->getIndex() == Index;
2371 case TemplateArgument::Expression: {
2372 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg.getAsExpr());
2373 if (!DRE || !DRE->getDecl())
2375 const NonTypeTemplateParmDecl *NTTP =
2376 dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl());
2377 return NTTP && NTTP->getDepth() == Depth && NTTP->getIndex() == Index;
2380 case TemplateArgument::Template:
2381 const TemplateTemplateParmDecl *TTP =
2382 dyn_cast_or_null<TemplateTemplateParmDecl>(
2383 Arg.getAsTemplateOrTemplatePattern().getAsTemplateDecl());
2384 return TTP && TTP->getDepth() == Depth && TTP->getIndex() == Index;
2386 llvm_unreachable("unexpected kind of template argument");
2389 static bool isSameAsPrimaryTemplate(TemplateParameterList *Params,
2390 ArrayRef<TemplateArgument> Args) {
2391 if (Params->size() != Args.size())
2394 unsigned Depth = Params->getDepth();
2396 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
2397 TemplateArgument Arg = Args[I];
2399 // If the parameter is a pack expansion, the argument must be a pack
2400 // whose only element is a pack expansion.
2401 if (Params->getParam(I)->isParameterPack()) {
2402 if (Arg.getKind() != TemplateArgument::Pack || Arg.pack_size() != 1 ||
2403 !Arg.pack_begin()->isPackExpansion())
2405 Arg = Arg.pack_begin()->getPackExpansionPattern();
2408 if (!isTemplateArgumentTemplateParameter(Arg, Depth, I))
2415 /// Convert the parser's template argument list representation into our form.
2416 static TemplateArgumentListInfo
2417 makeTemplateArgumentListInfo(Sema &S, TemplateIdAnnotation &TemplateId) {
2418 TemplateArgumentListInfo TemplateArgs(TemplateId.LAngleLoc,
2419 TemplateId.RAngleLoc);
2420 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId.getTemplateArgs(),
2421 TemplateId.NumArgs);
2422 S.translateTemplateArguments(TemplateArgsPtr, TemplateArgs);
2423 return TemplateArgs;
2426 DeclResult Sema::ActOnVarTemplateSpecialization(
2427 Scope *S, Declarator &D, TypeSourceInfo *DI, SourceLocation TemplateKWLoc,
2428 TemplateParameterList *TemplateParams, StorageClass SC,
2429 bool IsPartialSpecialization) {
2430 // D must be variable template id.
2431 assert(D.getName().getKind() == UnqualifiedId::IK_TemplateId &&
2432 "Variable template specialization is declared with a template it.");
2434 TemplateIdAnnotation *TemplateId = D.getName().TemplateId;
2435 TemplateArgumentListInfo TemplateArgs =
2436 makeTemplateArgumentListInfo(*this, *TemplateId);
2437 SourceLocation TemplateNameLoc = D.getIdentifierLoc();
2438 SourceLocation LAngleLoc = TemplateId->LAngleLoc;
2439 SourceLocation RAngleLoc = TemplateId->RAngleLoc;
2441 TemplateName Name = TemplateId->Template.get();
2443 // The template-id must name a variable template.
2444 VarTemplateDecl *VarTemplate =
2445 dyn_cast_or_null<VarTemplateDecl>(Name.getAsTemplateDecl());
2447 NamedDecl *FnTemplate;
2448 if (auto *OTS = Name.getAsOverloadedTemplate())
2449 FnTemplate = *OTS->begin();
2451 FnTemplate = dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl());
2453 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template_but_method)
2454 << FnTemplate->getDeclName();
2455 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template)
2456 << IsPartialSpecialization;
2459 // Check for unexpanded parameter packs in any of the template arguments.
2460 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2461 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
2462 UPPC_PartialSpecialization))
2465 // Check that the template argument list is well-formed for this
2467 SmallVector<TemplateArgument, 4> Converted;
2468 if (CheckTemplateArgumentList(VarTemplate, TemplateNameLoc, TemplateArgs,
2472 // Check that the type of this variable template specialization
2473 // matches the expected type.
2474 TypeSourceInfo *ExpectedDI;
2476 // Do substitution on the type of the declaration
2477 TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack,
2478 Converted.data(), Converted.size());
2479 InstantiatingTemplate Inst(*this, TemplateKWLoc, VarTemplate);
2480 if (Inst.isInvalid())
2482 VarDecl *Templated = VarTemplate->getTemplatedDecl();
2484 SubstType(Templated->getTypeSourceInfo(),
2485 MultiLevelTemplateArgumentList(TemplateArgList),
2486 Templated->getTypeSpecStartLoc(), Templated->getDeclName());
2491 // Find the variable template (partial) specialization declaration that
2492 // corresponds to these arguments.
2493 if (IsPartialSpecialization) {
2494 if (CheckTemplatePartialSpecializationArgs(
2495 *this, TemplateNameLoc, VarTemplate->getTemplateParameters(),
2496 TemplateArgs.size(), Converted))
2499 bool InstantiationDependent;
2500 if (!Name.isDependent() &&
2501 !TemplateSpecializationType::anyDependentTemplateArguments(
2502 TemplateArgs.getArgumentArray(), TemplateArgs.size(),
2503 InstantiationDependent)) {
2504 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
2505 << VarTemplate->getDeclName();
2506 IsPartialSpecialization = false;
2509 if (isSameAsPrimaryTemplate(VarTemplate->getTemplateParameters(),
2511 // C++ [temp.class.spec]p9b3:
2513 // -- The argument list of the specialization shall not be identical
2514 // to the implicit argument list of the primary template.
2515 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
2516 << /*variable template*/ 1
2517 << /*is definition*/(SC != SC_Extern && !CurContext->isRecord())
2518 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
2519 // FIXME: Recover from this by treating the declaration as a redeclaration
2520 // of the primary template.
2525 void *InsertPos = nullptr;
2526 VarTemplateSpecializationDecl *PrevDecl = nullptr;
2528 if (IsPartialSpecialization)
2529 // FIXME: Template parameter list matters too
2530 PrevDecl = VarTemplate->findPartialSpecialization(Converted, InsertPos);
2532 PrevDecl = VarTemplate->findSpecialization(Converted, InsertPos);
2534 VarTemplateSpecializationDecl *Specialization = nullptr;
2536 // Check whether we can declare a variable template specialization in
2537 // the current scope.
2538 if (CheckTemplateSpecializationScope(*this, VarTemplate, PrevDecl,
2540 IsPartialSpecialization))
2543 if (PrevDecl && PrevDecl->getSpecializationKind() == TSK_Undeclared) {
2544 // Since the only prior variable template specialization with these
2545 // arguments was referenced but not declared, reuse that
2546 // declaration node as our own, updating its source location and
2547 // the list of outer template parameters to reflect our new declaration.
2548 Specialization = PrevDecl;
2549 Specialization->setLocation(TemplateNameLoc);
2551 } else if (IsPartialSpecialization) {
2552 // Create a new class template partial specialization declaration node.
2553 VarTemplatePartialSpecializationDecl *PrevPartial =
2554 cast_or_null<VarTemplatePartialSpecializationDecl>(PrevDecl);
2555 VarTemplatePartialSpecializationDecl *Partial =
2556 VarTemplatePartialSpecializationDecl::Create(
2557 Context, VarTemplate->getDeclContext(), TemplateKWLoc,
2558 TemplateNameLoc, TemplateParams, VarTemplate, DI->getType(), DI, SC,
2559 Converted.data(), Converted.size(), TemplateArgs);
2562 VarTemplate->AddPartialSpecialization(Partial, InsertPos);
2563 Specialization = Partial;
2565 // If we are providing an explicit specialization of a member variable
2566 // template specialization, make a note of that.
2567 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
2568 PrevPartial->setMemberSpecialization();
2570 // Check that all of the template parameters of the variable template
2571 // partial specialization are deducible from the template
2572 // arguments. If not, this variable template partial specialization
2573 // will never be used.
2574 llvm::SmallBitVector DeducibleParams(TemplateParams->size());
2575 MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
2576 TemplateParams->getDepth(), DeducibleParams);
2578 if (!DeducibleParams.all()) {
2579 unsigned NumNonDeducible =
2580 DeducibleParams.size() - DeducibleParams.count();
2581 Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible)
2582 << /*variable template*/ 1 << (NumNonDeducible > 1)
2583 << SourceRange(TemplateNameLoc, RAngleLoc);
2584 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) {
2585 if (!DeducibleParams[I]) {
2586 NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I));
2587 if (Param->getDeclName())
2588 Diag(Param->getLocation(), diag::note_partial_spec_unused_parameter)
2589 << Param->getDeclName();
2591 Diag(Param->getLocation(), diag::note_partial_spec_unused_parameter)
2597 // Create a new class template specialization declaration node for
2598 // this explicit specialization or friend declaration.
2599 Specialization = VarTemplateSpecializationDecl::Create(
2600 Context, VarTemplate->getDeclContext(), TemplateKWLoc, TemplateNameLoc,
2601 VarTemplate, DI->getType(), DI, SC, Converted.data(), Converted.size());
2602 Specialization->setTemplateArgsInfo(TemplateArgs);
2605 VarTemplate->AddSpecialization(Specialization, InsertPos);
2608 // C++ [temp.expl.spec]p6:
2609 // If a template, a member template or the member of a class template is
2610 // explicitly specialized then that specialization shall be declared
2611 // before the first use of that specialization that would cause an implicit
2612 // instantiation to take place, in every translation unit in which such a
2613 // use occurs; no diagnostic is required.
2614 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
2616 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
2617 // Is there any previous explicit specialization declaration?
2618 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
2625 SourceRange Range(TemplateNameLoc, RAngleLoc);
2626 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
2629 Diag(PrevDecl->getPointOfInstantiation(),
2630 diag::note_instantiation_required_here)
2631 << (PrevDecl->getTemplateSpecializationKind() !=
2632 TSK_ImplicitInstantiation);
2637 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
2638 Specialization->setLexicalDeclContext(CurContext);
2640 // Add the specialization into its lexical context, so that it can
2641 // be seen when iterating through the list of declarations in that
2642 // context. However, specializations are not found by name lookup.
2643 CurContext->addDecl(Specialization);
2645 // Note that this is an explicit specialization.
2646 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
2649 // Check that this isn't a redefinition of this specialization,
2650 // merging with previous declarations.
2651 LookupResult PrevSpec(*this, GetNameForDeclarator(D), LookupOrdinaryName,
2653 PrevSpec.addDecl(PrevDecl);
2654 D.setRedeclaration(CheckVariableDeclaration(Specialization, PrevSpec));
2655 } else if (Specialization->isStaticDataMember() &&
2656 Specialization->isOutOfLine()) {
2657 Specialization->setAccess(VarTemplate->getAccess());
2660 // Link instantiations of static data members back to the template from
2661 // which they were instantiated.
2662 if (Specialization->isStaticDataMember())
2663 Specialization->setInstantiationOfStaticDataMember(
2664 VarTemplate->getTemplatedDecl(),
2665 Specialization->getSpecializationKind());
2667 return Specialization;
2671 /// \brief A partial specialization whose template arguments have matched
2672 /// a given template-id.
2673 struct PartialSpecMatchResult {
2674 VarTemplatePartialSpecializationDecl *Partial;
2675 TemplateArgumentList *Args;
2680 Sema::CheckVarTemplateId(VarTemplateDecl *Template, SourceLocation TemplateLoc,
2681 SourceLocation TemplateNameLoc,
2682 const TemplateArgumentListInfo &TemplateArgs) {
2683 assert(Template && "A variable template id without template?");
2685 // Check that the template argument list is well-formed for this template.
2686 SmallVector<TemplateArgument, 4> Converted;
2687 if (CheckTemplateArgumentList(
2688 Template, TemplateNameLoc,
2689 const_cast<TemplateArgumentListInfo &>(TemplateArgs), false,
2693 // Find the variable template specialization declaration that
2694 // corresponds to these arguments.
2695 void *InsertPos = nullptr;
2696 if (VarTemplateSpecializationDecl *Spec = Template->findSpecialization(
2697 Converted, InsertPos))
2698 // If we already have a variable template specialization, return it.
2701 // This is the first time we have referenced this variable template
2702 // specialization. Create the canonical declaration and add it to
2703 // the set of specializations, based on the closest partial specialization
2704 // that it represents. That is,
2705 VarDecl *InstantiationPattern = Template->getTemplatedDecl();
2706 TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack,
2707 Converted.data(), Converted.size());
2708 TemplateArgumentList *InstantiationArgs = &TemplateArgList;
2709 bool AmbiguousPartialSpec = false;
2710 typedef PartialSpecMatchResult MatchResult;
2711 SmallVector<MatchResult, 4> Matched;
2712 SourceLocation PointOfInstantiation = TemplateNameLoc;
2713 TemplateSpecCandidateSet FailedCandidates(PointOfInstantiation);
2715 // 1. Attempt to find the closest partial specialization that this
2716 // specializes, if any.
2717 // If any of the template arguments is dependent, then this is probably
2718 // a placeholder for an incomplete declarative context; which must be
2719 // complete by instantiation time. Thus, do not search through the partial
2720 // specializations yet.
2721 // TODO: Unify with InstantiateClassTemplateSpecialization()?
2722 // Perhaps better after unification of DeduceTemplateArguments() and
2723 // getMoreSpecializedPartialSpecialization().
2724 bool InstantiationDependent = false;
2725 if (!TemplateSpecializationType::anyDependentTemplateArguments(
2726 TemplateArgs, InstantiationDependent)) {
2728 SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
2729 Template->getPartialSpecializations(PartialSpecs);
2731 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) {
2732 VarTemplatePartialSpecializationDecl *Partial = PartialSpecs[I];
2733 TemplateDeductionInfo Info(FailedCandidates.getLocation());
2735 if (TemplateDeductionResult Result =
2736 DeduceTemplateArguments(Partial, TemplateArgList, Info)) {
2737 // Store the failed-deduction information for use in diagnostics, later.
2738 // TODO: Actually use the failed-deduction info?
2739 FailedCandidates.addCandidate()
2740 .set(Partial, MakeDeductionFailureInfo(Context, Result, Info));
2743 Matched.push_back(PartialSpecMatchResult());
2744 Matched.back().Partial = Partial;
2745 Matched.back().Args = Info.take();
2749 if (Matched.size() >= 1) {
2750 SmallVector<MatchResult, 4>::iterator Best = Matched.begin();
2751 if (Matched.size() == 1) {
2752 // -- If exactly one matching specialization is found, the
2753 // instantiation is generated from that specialization.
2754 // We don't need to do anything for this.
2756 // -- If more than one matching specialization is found, the
2757 // partial order rules (14.5.4.2) are used to determine
2758 // whether one of the specializations is more specialized
2759 // than the others. If none of the specializations is more
2760 // specialized than all of the other matching
2761 // specializations, then the use of the variable template is
2762 // ambiguous and the program is ill-formed.
2763 for (SmallVector<MatchResult, 4>::iterator P = Best + 1,
2764 PEnd = Matched.end();
2766 if (getMoreSpecializedPartialSpecialization(P->Partial, Best->Partial,
2767 PointOfInstantiation) ==
2772 // Determine if the best partial specialization is more specialized than
2774 for (SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
2775 PEnd = Matched.end();
2777 if (P != Best && getMoreSpecializedPartialSpecialization(
2778 P->Partial, Best->Partial,
2779 PointOfInstantiation) != Best->Partial) {
2780 AmbiguousPartialSpec = true;
2786 // Instantiate using the best variable template partial specialization.
2787 InstantiationPattern = Best->Partial;
2788 InstantiationArgs = Best->Args;
2790 // -- If no match is found, the instantiation is generated
2791 // from the primary template.
2792 // InstantiationPattern = Template->getTemplatedDecl();
2796 // 2. Create the canonical declaration.
2797 // Note that we do not instantiate the variable just yet, since
2798 // instantiation is handled in DoMarkVarDeclReferenced().
2799 // FIXME: LateAttrs et al.?
2800 VarTemplateSpecializationDecl *Decl = BuildVarTemplateInstantiation(
2801 Template, InstantiationPattern, *InstantiationArgs, TemplateArgs,
2802 Converted, TemplateNameLoc, InsertPos /*, LateAttrs, StartingScope*/);
2806 if (AmbiguousPartialSpec) {
2807 // Partial ordering did not produce a clear winner. Complain.
2808 Decl->setInvalidDecl();
2809 Diag(PointOfInstantiation, diag::err_partial_spec_ordering_ambiguous)
2812 // Print the matching partial specializations.
2813 for (SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
2814 PEnd = Matched.end();
2816 Diag(P->Partial->getLocation(), diag::note_partial_spec_match)
2817 << getTemplateArgumentBindingsText(
2818 P->Partial->getTemplateParameters(), *P->Args);
2822 if (VarTemplatePartialSpecializationDecl *D =
2823 dyn_cast<VarTemplatePartialSpecializationDecl>(InstantiationPattern))
2824 Decl->setInstantiationOf(D, InstantiationArgs);
2826 assert(Decl && "No variable template specialization?");
2831 Sema::CheckVarTemplateId(const CXXScopeSpec &SS,
2832 const DeclarationNameInfo &NameInfo,
2833 VarTemplateDecl *Template, SourceLocation TemplateLoc,
2834 const TemplateArgumentListInfo *TemplateArgs) {
2836 DeclResult Decl = CheckVarTemplateId(Template, TemplateLoc, NameInfo.getLoc(),
2838 if (Decl.isInvalid())
2841 VarDecl *Var = cast<VarDecl>(Decl.get());
2842 if (!Var->getTemplateSpecializationKind())
2843 Var->setTemplateSpecializationKind(TSK_ImplicitInstantiation,
2846 // Build an ordinary singleton decl ref.
2847 return BuildDeclarationNameExpr(SS, NameInfo, Var,
2848 /*FoundD=*/nullptr, TemplateArgs);
2851 ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS,
2852 SourceLocation TemplateKWLoc,
2855 const TemplateArgumentListInfo *TemplateArgs) {
2856 // FIXME: Can we do any checking at this point? I guess we could check the
2857 // template arguments that we have against the template name, if the template
2858 // name refers to a single template. That's not a terribly common case,
2860 // foo<int> could identify a single function unambiguously
2861 // This approach does NOT work, since f<int>(1);
2862 // gets resolved prior to resorting to overload resolution
2863 // i.e., template<class T> void f(double);
2864 // vs template<class T, class U> void f(U);
2866 // These should be filtered out by our callers.
2867 assert(!R.empty() && "empty lookup results when building templateid");
2868 assert(!R.isAmbiguous() && "ambiguous lookup when building templateid");
2870 // In C++1y, check variable template ids.
2871 bool InstantiationDependent;
2872 if (R.getAsSingle<VarTemplateDecl>() &&
2873 !TemplateSpecializationType::anyDependentTemplateArguments(
2874 *TemplateArgs, InstantiationDependent)) {
2875 return CheckVarTemplateId(SS, R.getLookupNameInfo(),
2876 R.getAsSingle<VarTemplateDecl>(),
2877 TemplateKWLoc, TemplateArgs);
2880 // We don't want lookup warnings at this point.
2881 R.suppressDiagnostics();
2883 UnresolvedLookupExpr *ULE
2884 = UnresolvedLookupExpr::Create(Context, R.getNamingClass(),
2885 SS.getWithLocInContext(Context),
2887 R.getLookupNameInfo(),
2888 RequiresADL, TemplateArgs,
2889 R.begin(), R.end());
2894 // We actually only call this from template instantiation.
2896 Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS,
2897 SourceLocation TemplateKWLoc,
2898 const DeclarationNameInfo &NameInfo,
2899 const TemplateArgumentListInfo *TemplateArgs) {
2901 assert(TemplateArgs || TemplateKWLoc.isValid());
2903 if (!(DC = computeDeclContext(SS, false)) ||
2904 DC->isDependentContext() ||
2905 RequireCompleteDeclContext(SS, DC))
2906 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
2908 bool MemberOfUnknownSpecialization;
2909 LookupResult R(*this, NameInfo, LookupOrdinaryName);
2910 LookupTemplateName(R, (Scope*)nullptr, SS, QualType(), /*Entering*/ false,
2911 MemberOfUnknownSpecialization);
2913 if (R.isAmbiguous())
2917 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_non_template)
2918 << NameInfo.getName() << SS.getRange();
2922 if (ClassTemplateDecl *Temp = R.getAsSingle<ClassTemplateDecl>()) {
2923 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_class_template)
2925 << NameInfo.getName().getAsString() << SS.getRange();
2926 Diag(Temp->getLocation(), diag::note_referenced_class_template);
2930 return BuildTemplateIdExpr(SS, TemplateKWLoc, R, /*ADL*/ false, TemplateArgs);
2933 /// \brief Form a dependent template name.
2935 /// This action forms a dependent template name given the template
2936 /// name and its (presumably dependent) scope specifier. For
2937 /// example, given "MetaFun::template apply", the scope specifier \p
2938 /// SS will be "MetaFun::", \p TemplateKWLoc contains the location
2939 /// of the "template" keyword, and "apply" is the \p Name.
2940 TemplateNameKind Sema::ActOnDependentTemplateName(Scope *S,
2942 SourceLocation TemplateKWLoc,
2943 UnqualifiedId &Name,
2944 ParsedType ObjectType,
2945 bool EnteringContext,
2946 TemplateTy &Result) {
2947 if (TemplateKWLoc.isValid() && S && !S->getTemplateParamParent())
2949 getLangOpts().CPlusPlus11 ?
2950 diag::warn_cxx98_compat_template_outside_of_template :
2951 diag::ext_template_outside_of_template)
2952 << FixItHint::CreateRemoval(TemplateKWLoc);
2954 DeclContext *LookupCtx = nullptr;
2956 LookupCtx = computeDeclContext(SS, EnteringContext);
2957 if (!LookupCtx && ObjectType)
2958 LookupCtx = computeDeclContext(ObjectType.get());
2960 // C++0x [temp.names]p5:
2961 // If a name prefixed by the keyword template is not the name of
2962 // a template, the program is ill-formed. [Note: the keyword
2963 // template may not be applied to non-template members of class
2964 // templates. -end note ] [ Note: as is the case with the
2965 // typename prefix, the template prefix is allowed in cases
2966 // where it is not strictly necessary; i.e., when the
2967 // nested-name-specifier or the expression on the left of the ->
2968 // or . is not dependent on a template-parameter, or the use
2969 // does not appear in the scope of a template. -end note]
2971 // Note: C++03 was more strict here, because it banned the use of
2972 // the "template" keyword prior to a template-name that was not a
2973 // dependent name. C++ DR468 relaxed this requirement (the
2974 // "template" keyword is now permitted). We follow the C++0x
2975 // rules, even in C++03 mode with a warning, retroactively applying the DR.
2976 bool MemberOfUnknownSpecialization;
2977 TemplateNameKind TNK = isTemplateName(S, SS, TemplateKWLoc.isValid(), Name,
2978 ObjectType, EnteringContext, Result,
2979 MemberOfUnknownSpecialization);
2980 if (TNK == TNK_Non_template && LookupCtx->isDependentContext() &&
2981 isa<CXXRecordDecl>(LookupCtx) &&
2982 (!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() ||
2983 cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases())) {
2984 // This is a dependent template. Handle it below.
2985 } else if (TNK == TNK_Non_template) {
2986 Diag(Name.getLocStart(),
2987 diag::err_template_kw_refers_to_non_template)
2988 << GetNameFromUnqualifiedId(Name).getName()
2989 << Name.getSourceRange()
2991 return TNK_Non_template;
2993 // We found something; return it.
2998 NestedNameSpecifier *Qualifier = SS.getScopeRep();
3000 switch (Name.getKind()) {
3001 case UnqualifiedId::IK_Identifier:
3002 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier,
3004 return TNK_Dependent_template_name;
3006 case UnqualifiedId::IK_OperatorFunctionId:
3007 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier,
3008 Name.OperatorFunctionId.Operator));
3009 return TNK_Function_template;
3011 case UnqualifiedId::IK_LiteralOperatorId:
3012 llvm_unreachable("literal operator id cannot have a dependent scope");
3018 Diag(Name.getLocStart(),
3019 diag::err_template_kw_refers_to_non_template)
3020 << GetNameFromUnqualifiedId(Name).getName()
3021 << Name.getSourceRange()
3023 return TNK_Non_template;
3026 bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param,
3027 TemplateArgumentLoc &AL,
3028 SmallVectorImpl<TemplateArgument> &Converted) {
3029 const TemplateArgument &Arg = AL.getArgument();
3031 TypeSourceInfo *TSI = nullptr;
3033 // Check template type parameter.
3034 switch(Arg.getKind()) {
3035 case TemplateArgument::Type:
3036 // C++ [temp.arg.type]p1:
3037 // A template-argument for a template-parameter which is a
3038 // type shall be a type-id.
3039 ArgType = Arg.getAsType();
3040 TSI = AL.getTypeSourceInfo();
3042 case TemplateArgument::Template: {
3043 // We have a template type parameter but the template argument
3044 // is a template without any arguments.
3045 SourceRange SR = AL.getSourceRange();
3046 TemplateName Name = Arg.getAsTemplate();
3047 Diag(SR.getBegin(), diag::err_template_missing_args)
3049 if (TemplateDecl *Decl = Name.getAsTemplateDecl())
3050 Diag(Decl->getLocation(), diag::note_template_decl_here);
3054 case TemplateArgument::Expression: {
3055 // We have a template type parameter but the template argument is an
3056 // expression; see if maybe it is missing the "typename" keyword.
3058 DeclarationNameInfo NameInfo;
3060 if (DeclRefExpr *ArgExpr = dyn_cast<DeclRefExpr>(Arg.getAsExpr())) {
3061 SS.Adopt(ArgExpr->getQualifierLoc());
3062 NameInfo = ArgExpr->getNameInfo();
3063 } else if (DependentScopeDeclRefExpr *ArgExpr =
3064 dyn_cast<DependentScopeDeclRefExpr>(Arg.getAsExpr())) {
3065 SS.Adopt(ArgExpr->getQualifierLoc());
3066 NameInfo = ArgExpr->getNameInfo();
3067 } else if (CXXDependentScopeMemberExpr *ArgExpr =
3068 dyn_cast<CXXDependentScopeMemberExpr>(Arg.getAsExpr())) {
3069 if (ArgExpr->isImplicitAccess()) {
3070 SS.Adopt(ArgExpr->getQualifierLoc());
3071 NameInfo = ArgExpr->getMemberNameInfo();
3075 if (auto *II = NameInfo.getName().getAsIdentifierInfo()) {
3076 LookupResult Result(*this, NameInfo, LookupOrdinaryName);
3077 LookupParsedName(Result, CurScope, &SS);
3079 if (Result.getAsSingle<TypeDecl>() ||
3080 Result.getResultKind() ==
3081 LookupResult::NotFoundInCurrentInstantiation) {
3082 // Suggest that the user add 'typename' before the NNS.
3083 SourceLocation Loc = AL.getSourceRange().getBegin();
3084 Diag(Loc, getLangOpts().MSVCCompat
3085 ? diag::ext_ms_template_type_arg_missing_typename
3086 : diag::err_template_arg_must_be_type_suggest)
3087 << FixItHint::CreateInsertion(Loc, "typename ");
3088 Diag(Param->getLocation(), diag::note_template_param_here);
3090 // Recover by synthesizing a type using the location information that we
3093 Context.getDependentNameType(ETK_Typename, SS.getScopeRep(), II);
3095 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(ArgType);
3096 TL.setElaboratedKeywordLoc(SourceLocation(/*synthesized*/));
3097 TL.setQualifierLoc(SS.getWithLocInContext(Context));
3098 TL.setNameLoc(NameInfo.getLoc());
3099 TSI = TLB.getTypeSourceInfo(Context, ArgType);
3101 // Overwrite our input TemplateArgumentLoc so that we can recover
3103 AL = TemplateArgumentLoc(TemplateArgument(ArgType),
3104 TemplateArgumentLocInfo(TSI));
3112 // We have a template type parameter but the template argument
3114 SourceRange SR = AL.getSourceRange();
3115 Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR;
3116 Diag(Param->getLocation(), diag::note_template_param_here);
3122 if (CheckTemplateArgument(Param, TSI))
3125 // Add the converted template type argument.
3126 ArgType = Context.getCanonicalType(ArgType);
3129 // If an explicitly-specified template argument type is a lifetime type
3130 // with no lifetime qualifier, the __strong lifetime qualifier is inferred.
3131 if (getLangOpts().ObjCAutoRefCount &&
3132 ArgType->isObjCLifetimeType() &&
3133 !ArgType.getObjCLifetime()) {
3135 Qs.setObjCLifetime(Qualifiers::OCL_Strong);
3136 ArgType = Context.getQualifiedType(ArgType, Qs);
3139 Converted.push_back(TemplateArgument(ArgType));
3143 /// \brief Substitute template arguments into the default template argument for
3144 /// the given template type parameter.
3146 /// \param SemaRef the semantic analysis object for which we are performing
3147 /// the substitution.
3149 /// \param Template the template that we are synthesizing template arguments
3152 /// \param TemplateLoc the location of the template name that started the
3153 /// template-id we are checking.
3155 /// \param RAngleLoc the location of the right angle bracket ('>') that
3156 /// terminates the template-id.
3158 /// \param Param the template template parameter whose default we are
3159 /// substituting into.
3161 /// \param Converted the list of template arguments provided for template
3162 /// parameters that precede \p Param in the template parameter list.
3163 /// \returns the substituted template argument, or NULL if an error occurred.
3164 static TypeSourceInfo *
3165 SubstDefaultTemplateArgument(Sema &SemaRef,
3166 TemplateDecl *Template,
3167 SourceLocation TemplateLoc,
3168 SourceLocation RAngleLoc,
3169 TemplateTypeParmDecl *Param,
3170 SmallVectorImpl<TemplateArgument> &Converted) {
3171 TypeSourceInfo *ArgType = Param->getDefaultArgumentInfo();
3173 // If the argument type is dependent, instantiate it now based
3174 // on the previously-computed template arguments.
3175 if (ArgType->getType()->isDependentType()) {
3176 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
3177 Template, Converted,
3178 SourceRange(TemplateLoc, RAngleLoc));
3179 if (Inst.isInvalid())
3182 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
3183 Converted.data(), Converted.size());
3185 // Only substitute for the innermost template argument list.
3186 MultiLevelTemplateArgumentList TemplateArgLists;
3187 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3188 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3189 TemplateArgLists.addOuterTemplateArguments(None);
3191 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
3193 SemaRef.SubstType(ArgType, TemplateArgLists,
3194 Param->getDefaultArgumentLoc(), Param->getDeclName());
3200 /// \brief Substitute template arguments into the default template argument for
3201 /// the given non-type template parameter.
3203 /// \param SemaRef the semantic analysis object for which we are performing
3204 /// the substitution.
3206 /// \param Template the template that we are synthesizing template arguments
3209 /// \param TemplateLoc the location of the template name that started the
3210 /// template-id we are checking.
3212 /// \param RAngleLoc the location of the right angle bracket ('>') that
3213 /// terminates the template-id.
3215 /// \param Param the non-type template parameter whose default we are
3216 /// substituting into.
3218 /// \param Converted the list of template arguments provided for template
3219 /// parameters that precede \p Param in the template parameter list.
3221 /// \returns the substituted template argument, or NULL if an error occurred.
3223 SubstDefaultTemplateArgument(Sema &SemaRef,
3224 TemplateDecl *Template,
3225 SourceLocation TemplateLoc,
3226 SourceLocation RAngleLoc,
3227 NonTypeTemplateParmDecl *Param,
3228 SmallVectorImpl<TemplateArgument> &Converted) {
3229 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
3230 Template, Converted,
3231 SourceRange(TemplateLoc, RAngleLoc));
3232 if (Inst.isInvalid())
3235 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
3236 Converted.data(), Converted.size());
3238 // Only substitute for the innermost template argument list.
3239 MultiLevelTemplateArgumentList TemplateArgLists;
3240 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3241 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3242 TemplateArgLists.addOuterTemplateArguments(None);
3244 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
3245 EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
3246 return SemaRef.SubstExpr(Param->getDefaultArgument(), TemplateArgLists);
3249 /// \brief Substitute template arguments into the default template argument for
3250 /// the given template template parameter.
3252 /// \param SemaRef the semantic analysis object for which we are performing
3253 /// the substitution.
3255 /// \param Template the template that we are synthesizing template arguments
3258 /// \param TemplateLoc the location of the template name that started the
3259 /// template-id we are checking.
3261 /// \param RAngleLoc the location of the right angle bracket ('>') that
3262 /// terminates the template-id.
3264 /// \param Param the template template parameter whose default we are
3265 /// substituting into.
3267 /// \param Converted the list of template arguments provided for template
3268 /// parameters that precede \p Param in the template parameter list.
3270 /// \param QualifierLoc Will be set to the nested-name-specifier (with
3271 /// source-location information) that precedes the template name.
3273 /// \returns the substituted template argument, or NULL if an error occurred.
3275 SubstDefaultTemplateArgument(Sema &SemaRef,
3276 TemplateDecl *Template,
3277 SourceLocation TemplateLoc,
3278 SourceLocation RAngleLoc,
3279 TemplateTemplateParmDecl *Param,
3280 SmallVectorImpl<TemplateArgument> &Converted,
3281 NestedNameSpecifierLoc &QualifierLoc) {
3282 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, Template, Converted,
3283 SourceRange(TemplateLoc, RAngleLoc));
3284 if (Inst.isInvalid())
3285 return TemplateName();
3287 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
3288 Converted.data(), Converted.size());
3290 // Only substitute for the innermost template argument list.
3291 MultiLevelTemplateArgumentList TemplateArgLists;
3292 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3293 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3294 TemplateArgLists.addOuterTemplateArguments(None);
3296 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
3297 // Substitute into the nested-name-specifier first,
3298 QualifierLoc = Param->getDefaultArgument().getTemplateQualifierLoc();
3301 SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgLists);
3303 return TemplateName();
3306 return SemaRef.SubstTemplateName(
3308 Param->getDefaultArgument().getArgument().getAsTemplate(),
3309 Param->getDefaultArgument().getTemplateNameLoc(),
3313 /// \brief If the given template parameter has a default template
3314 /// argument, substitute into that default template argument and
3315 /// return the corresponding template argument.
3317 Sema::SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template,
3318 SourceLocation TemplateLoc,
3319 SourceLocation RAngleLoc,
3321 SmallVectorImpl<TemplateArgument>
3323 bool &HasDefaultArg) {
3324 HasDefaultArg = false;
3326 if (TemplateTypeParmDecl *TypeParm = dyn_cast<TemplateTypeParmDecl>(Param)) {
3327 if (!hasVisibleDefaultArgument(TypeParm))
3328 return TemplateArgumentLoc();
3330 HasDefaultArg = true;
3331 TypeSourceInfo *DI = SubstDefaultTemplateArgument(*this, Template,
3337 return TemplateArgumentLoc(TemplateArgument(DI->getType()), DI);
3339 return TemplateArgumentLoc();
3342 if (NonTypeTemplateParmDecl *NonTypeParm
3343 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3344 if (!hasVisibleDefaultArgument(NonTypeParm))
3345 return TemplateArgumentLoc();
3347 HasDefaultArg = true;
3348 ExprResult Arg = SubstDefaultTemplateArgument(*this, Template,
3353 if (Arg.isInvalid())
3354 return TemplateArgumentLoc();
3356 Expr *ArgE = Arg.getAs<Expr>();
3357 return TemplateArgumentLoc(TemplateArgument(ArgE), ArgE);
3360 TemplateTemplateParmDecl *TempTempParm
3361 = cast<TemplateTemplateParmDecl>(Param);
3362 if (!hasVisibleDefaultArgument(TempTempParm))
3363 return TemplateArgumentLoc();
3365 HasDefaultArg = true;
3366 NestedNameSpecifierLoc QualifierLoc;
3367 TemplateName TName = SubstDefaultTemplateArgument(*this, Template,
3374 return TemplateArgumentLoc();
3376 return TemplateArgumentLoc(TemplateArgument(TName),
3377 TempTempParm->getDefaultArgument().getTemplateQualifierLoc(),
3378 TempTempParm->getDefaultArgument().getTemplateNameLoc());
3381 /// \brief Check that the given template argument corresponds to the given
3382 /// template parameter.
3384 /// \param Param The template parameter against which the argument will be
3387 /// \param Arg The template argument, which may be updated due to conversions.
3389 /// \param Template The template in which the template argument resides.
3391 /// \param TemplateLoc The location of the template name for the template
3392 /// whose argument list we're matching.
3394 /// \param RAngleLoc The location of the right angle bracket ('>') that closes
3395 /// the template argument list.
3397 /// \param ArgumentPackIndex The index into the argument pack where this
3398 /// argument will be placed. Only valid if the parameter is a parameter pack.
3400 /// \param Converted The checked, converted argument will be added to the
3401 /// end of this small vector.
3403 /// \param CTAK Describes how we arrived at this particular template argument:
3404 /// explicitly written, deduced, etc.
3406 /// \returns true on error, false otherwise.
3407 bool Sema::CheckTemplateArgument(NamedDecl *Param,
3408 TemplateArgumentLoc &Arg,
3409 NamedDecl *Template,
3410 SourceLocation TemplateLoc,
3411 SourceLocation RAngleLoc,
3412 unsigned ArgumentPackIndex,
3413 SmallVectorImpl<TemplateArgument> &Converted,
3414 CheckTemplateArgumentKind CTAK) {
3415 // Check template type parameters.
3416 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param))
3417 return CheckTemplateTypeArgument(TTP, Arg, Converted);
3419 // Check non-type template parameters.
3420 if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3421 // Do substitution on the type of the non-type template parameter
3422 // with the template arguments we've seen thus far. But if the
3423 // template has a dependent context then we cannot substitute yet.
3424 QualType NTTPType = NTTP->getType();
3425 if (NTTP->isParameterPack() && NTTP->isExpandedParameterPack())
3426 NTTPType = NTTP->getExpansionType(ArgumentPackIndex);
3428 if (NTTPType->isDependentType() &&
3429 !isa<TemplateTemplateParmDecl>(Template) &&
3430 !Template->getDeclContext()->isDependentContext()) {
3431 // Do substitution on the type of the non-type template parameter.
3432 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
3434 SourceRange(TemplateLoc, RAngleLoc));
3435 if (Inst.isInvalid())
3438 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
3439 Converted.data(), Converted.size());
3440 NTTPType = SubstType(NTTPType,
3441 MultiLevelTemplateArgumentList(TemplateArgs),
3442 NTTP->getLocation(),
3443 NTTP->getDeclName());
3444 // If that worked, check the non-type template parameter type
3446 if (!NTTPType.isNull())
3447 NTTPType = CheckNonTypeTemplateParameterType(NTTPType,
3448 NTTP->getLocation());
3449 if (NTTPType.isNull())
3453 switch (Arg.getArgument().getKind()) {
3454 case TemplateArgument::Null:
3455 llvm_unreachable("Should never see a NULL template argument here");
3457 case TemplateArgument::Expression: {
3458 TemplateArgument Result;
3460 CheckTemplateArgument(NTTP, NTTPType, Arg.getArgument().getAsExpr(),
3462 if (Res.isInvalid())
3465 // If the resulting expression is new, then use it in place of the
3466 // old expression in the template argument.
3467 if (Res.get() != Arg.getArgument().getAsExpr()) {
3468 TemplateArgument TA(Res.get());
3469 Arg = TemplateArgumentLoc(TA, Res.get());
3472 Converted.push_back(Result);
3476 case TemplateArgument::Declaration:
3477 case TemplateArgument::Integral:
3478 case TemplateArgument::NullPtr:
3479 // We've already checked this template argument, so just copy
3480 // it to the list of converted arguments.
3481 Converted.push_back(Arg.getArgument());
3484 case TemplateArgument::Template:
3485 case TemplateArgument::TemplateExpansion:
3486 // We were given a template template argument. It may not be ill-formed;
3488 if (DependentTemplateName *DTN
3489 = Arg.getArgument().getAsTemplateOrTemplatePattern()
3490 .getAsDependentTemplateName()) {
3491 // We have a template argument such as \c T::template X, which we
3492 // parsed as a template template argument. However, since we now
3493 // know that we need a non-type template argument, convert this
3494 // template name into an expression.
3496 DeclarationNameInfo NameInfo(DTN->getIdentifier(),
3497 Arg.getTemplateNameLoc());
3500 SS.Adopt(Arg.getTemplateQualifierLoc());
3501 // FIXME: the template-template arg was a DependentTemplateName,
3502 // so it was provided with a template keyword. However, its source
3503 // location is not stored in the template argument structure.
3504 SourceLocation TemplateKWLoc;
3505 ExprResult E = DependentScopeDeclRefExpr::Create(
3506 Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo,
3509 // If we parsed the template argument as a pack expansion, create a
3510 // pack expansion expression.
3511 if (Arg.getArgument().getKind() == TemplateArgument::TemplateExpansion){
3512 E = ActOnPackExpansion(E.get(), Arg.getTemplateEllipsisLoc());
3517 TemplateArgument Result;
3518 E = CheckTemplateArgument(NTTP, NTTPType, E.get(), Result);
3522 Converted.push_back(Result);
3526 // We have a template argument that actually does refer to a class
3527 // template, alias template, or template template parameter, and
3528 // therefore cannot be a non-type template argument.
3529 Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr)
3530 << Arg.getSourceRange();
3532 Diag(Param->getLocation(), diag::note_template_param_here);
3535 case TemplateArgument::Type: {
3536 // We have a non-type template parameter but the template
3537 // argument is a type.
3539 // C++ [temp.arg]p2:
3540 // In a template-argument, an ambiguity between a type-id and
3541 // an expression is resolved to a type-id, regardless of the
3542 // form of the corresponding template-parameter.
3544 // We warn specifically about this case, since it can be rather
3545 // confusing for users.
3546 QualType T = Arg.getArgument().getAsType();
3547 SourceRange SR = Arg.getSourceRange();
3548 if (T->isFunctionType())
3549 Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T;
3551 Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR;
3552 Diag(Param->getLocation(), diag::note_template_param_here);
3556 case TemplateArgument::Pack:
3557 llvm_unreachable("Caller must expand template argument packs");
3564 // Check template template parameters.
3565 TemplateTemplateParmDecl *TempParm = cast<TemplateTemplateParmDecl>(Param);
3567 // Substitute into the template parameter list of the template
3568 // template parameter, since previously-supplied template arguments
3569 // may appear within the template template parameter.
3571 // Set up a template instantiation context.
3572 LocalInstantiationScope Scope(*this);
3573 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
3574 TempParm, Converted,
3575 SourceRange(TemplateLoc, RAngleLoc));
3576 if (Inst.isInvalid())
3579 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
3580 Converted.data(), Converted.size());
3581 TempParm = cast_or_null<TemplateTemplateParmDecl>(
3582 SubstDecl(TempParm, CurContext,
3583 MultiLevelTemplateArgumentList(TemplateArgs)));
3588 switch (Arg.getArgument().getKind()) {
3589 case TemplateArgument::Null:
3590 llvm_unreachable("Should never see a NULL template argument here");
3592 case TemplateArgument::Template:
3593 case TemplateArgument::TemplateExpansion:
3594 if (CheckTemplateArgument(TempParm, Arg, ArgumentPackIndex))
3597 Converted.push_back(Arg.getArgument());
3600 case TemplateArgument::Expression:
3601 case TemplateArgument::Type:
3602 // We have a template template parameter but the template
3603 // argument does not refer to a template.
3604 Diag(Arg.getLocation(), diag::err_template_arg_must_be_template)
3605 << getLangOpts().CPlusPlus11;
3608 case TemplateArgument::Declaration:
3609 llvm_unreachable("Declaration argument with template template parameter");
3610 case TemplateArgument::Integral:
3611 llvm_unreachable("Integral argument with template template parameter");
3612 case TemplateArgument::NullPtr:
3613 llvm_unreachable("Null pointer argument with template template parameter");
3615 case TemplateArgument::Pack:
3616 llvm_unreachable("Caller must expand template argument packs");
3622 /// \brief Diagnose an arity mismatch in the
3623 static bool diagnoseArityMismatch(Sema &S, TemplateDecl *Template,
3624 SourceLocation TemplateLoc,
3625 TemplateArgumentListInfo &TemplateArgs) {
3626 TemplateParameterList *Params = Template->getTemplateParameters();
3627 unsigned NumParams = Params->size();
3628 unsigned NumArgs = TemplateArgs.size();
3631 if (NumArgs > NumParams)
3632 Range = SourceRange(TemplateArgs[NumParams].getLocation(),
3633 TemplateArgs.getRAngleLoc());
3634 S.Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
3635 << (NumArgs > NumParams)
3636 << (isa<ClassTemplateDecl>(Template)? 0 :
3637 isa<FunctionTemplateDecl>(Template)? 1 :
3638 isa<TemplateTemplateParmDecl>(Template)? 2 : 3)
3639 << Template << Range;
3640 S.Diag(Template->getLocation(), diag::note_template_decl_here)
3641 << Params->getSourceRange();
3645 /// \brief Check whether the template parameter is a pack expansion, and if so,
3646 /// determine the number of parameters produced by that expansion. For instance:
3649 /// template<typename ...Ts> struct A {
3650 /// template<Ts ...NTs, template<Ts> class ...TTs, typename ...Us> struct B;
3654 /// In \c A<int,int>::B, \c NTs and \c TTs have expanded pack size 2, and \c Us
3655 /// is not a pack expansion, so returns an empty Optional.
3656 static Optional<unsigned> getExpandedPackSize(NamedDecl *Param) {
3657 if (NonTypeTemplateParmDecl *NTTP
3658 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3659 if (NTTP->isExpandedParameterPack())
3660 return NTTP->getNumExpansionTypes();
3663 if (TemplateTemplateParmDecl *TTP
3664 = dyn_cast<TemplateTemplateParmDecl>(Param)) {
3665 if (TTP->isExpandedParameterPack())
3666 return TTP->getNumExpansionTemplateParameters();
3672 /// Diagnose a missing template argument.
3673 template<typename TemplateParmDecl>
3674 static bool diagnoseMissingArgument(Sema &S, SourceLocation Loc,
3676 const TemplateParmDecl *D,
3677 TemplateArgumentListInfo &Args) {
3678 // Dig out the most recent declaration of the template parameter; there may be
3679 // declarations of the template that are more recent than TD.
3680 D = cast<TemplateParmDecl>(cast<TemplateDecl>(TD->getMostRecentDecl())
3681 ->getTemplateParameters()
3682 ->getParam(D->getIndex()));
3684 // If there's a default argument that's not visible, diagnose that we're
3685 // missing a module import.
3686 llvm::SmallVector<Module*, 8> Modules;
3687 if (D->hasDefaultArgument() && !S.hasVisibleDefaultArgument(D, &Modules)) {
3688 S.diagnoseMissingImport(Loc, cast<NamedDecl>(TD),
3689 D->getDefaultArgumentLoc(), Modules,
3690 Sema::MissingImportKind::DefaultArgument,
3695 // FIXME: If there's a more recent default argument that *is* visible,
3696 // diagnose that it was declared too late.
3698 return diagnoseArityMismatch(S, TD, Loc, Args);
3701 /// \brief Check that the given template argument list is well-formed
3702 /// for specializing the given template.
3703 bool Sema::CheckTemplateArgumentList(TemplateDecl *Template,
3704 SourceLocation TemplateLoc,
3705 TemplateArgumentListInfo &TemplateArgs,
3706 bool PartialTemplateArgs,
3707 SmallVectorImpl<TemplateArgument> &Converted) {
3708 // Make a copy of the template arguments for processing. Only make the
3709 // changes at the end when successful in matching the arguments to the
3711 TemplateArgumentListInfo NewArgs = TemplateArgs;
3713 TemplateParameterList *Params = Template->getTemplateParameters();
3715 SourceLocation RAngleLoc = NewArgs.getRAngleLoc();
3717 // C++ [temp.arg]p1:
3718 // [...] The type and form of each template-argument specified in
3719 // a template-id shall match the type and form specified for the
3720 // corresponding parameter declared by the template in its
3721 // template-parameter-list.
3722 bool isTemplateTemplateParameter = isa<TemplateTemplateParmDecl>(Template);
3723 SmallVector<TemplateArgument, 2> ArgumentPack;
3724 unsigned ArgIdx = 0, NumArgs = NewArgs.size();
3725 LocalInstantiationScope InstScope(*this, true);
3726 for (TemplateParameterList::iterator Param = Params->begin(),
3727 ParamEnd = Params->end();
3728 Param != ParamEnd; /* increment in loop */) {
3729 // If we have an expanded parameter pack, make sure we don't have too
3731 if (Optional<unsigned> Expansions = getExpandedPackSize(*Param)) {
3732 if (*Expansions == ArgumentPack.size()) {
3733 // We're done with this parameter pack. Pack up its arguments and add
3734 // them to the list.
3735 Converted.push_back(
3736 TemplateArgument::CreatePackCopy(Context,
3737 ArgumentPack.data(),
3738 ArgumentPack.size()));
3739 ArgumentPack.clear();
3741 // This argument is assigned to the next parameter.
3744 } else if (ArgIdx == NumArgs && !PartialTemplateArgs) {
3745 // Not enough arguments for this parameter pack.
3746 Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
3748 << (isa<ClassTemplateDecl>(Template)? 0 :
3749 isa<FunctionTemplateDecl>(Template)? 1 :
3750 isa<TemplateTemplateParmDecl>(Template)? 2 : 3)
3752 Diag(Template->getLocation(), diag::note_template_decl_here)
3753 << Params->getSourceRange();
3758 if (ArgIdx < NumArgs) {
3759 // Check the template argument we were given.
3760 if (CheckTemplateArgument(*Param, NewArgs[ArgIdx], Template,
3761 TemplateLoc, RAngleLoc,
3762 ArgumentPack.size(), Converted))
3765 bool PackExpansionIntoNonPack =
3766 NewArgs[ArgIdx].getArgument().isPackExpansion() &&
3767 (!(*Param)->isTemplateParameterPack() || getExpandedPackSize(*Param));
3768 if (PackExpansionIntoNonPack && isa<TypeAliasTemplateDecl>(Template)) {
3769 // Core issue 1430: we have a pack expansion as an argument to an
3770 // alias template, and it's not part of a parameter pack. This
3771 // can't be canonicalized, so reject it now.
3772 Diag(NewArgs[ArgIdx].getLocation(),
3773 diag::err_alias_template_expansion_into_fixed_list)
3774 << NewArgs[ArgIdx].getSourceRange();
3775 Diag((*Param)->getLocation(), diag::note_template_param_here);
3779 // We're now done with this argument.
3782 if ((*Param)->isTemplateParameterPack()) {
3783 // The template parameter was a template parameter pack, so take the
3784 // deduced argument and place it on the argument pack. Note that we
3785 // stay on the same template parameter so that we can deduce more
3787 ArgumentPack.push_back(Converted.pop_back_val());
3789 // Move to the next template parameter.
3793 // If we just saw a pack expansion into a non-pack, then directly convert
3794 // the remaining arguments, because we don't know what parameters they'll
3796 if (PackExpansionIntoNonPack) {
3797 if (!ArgumentPack.empty()) {
3798 // If we were part way through filling in an expanded parameter pack,
3799 // fall back to just producing individual arguments.
3800 Converted.insert(Converted.end(),
3801 ArgumentPack.begin(), ArgumentPack.end());
3802 ArgumentPack.clear();
3805 while (ArgIdx < NumArgs) {
3806 Converted.push_back(NewArgs[ArgIdx].getArgument());
3816 // If we're checking a partial template argument list, we're done.
3817 if (PartialTemplateArgs) {
3818 if ((*Param)->isTemplateParameterPack() && !ArgumentPack.empty())
3819 Converted.push_back(TemplateArgument::CreatePackCopy(Context,
3820 ArgumentPack.data(),
3821 ArgumentPack.size()));
3826 // If we have a template parameter pack with no more corresponding
3827 // arguments, just break out now and we'll fill in the argument pack below.
3828 if ((*Param)->isTemplateParameterPack()) {
3829 assert(!getExpandedPackSize(*Param) &&
3830 "Should have dealt with this already");
3832 // A non-expanded parameter pack before the end of the parameter list
3833 // only occurs for an ill-formed template parameter list, unless we've
3834 // got a partial argument list for a function template, so just bail out.
3835 if (Param + 1 != ParamEnd)
3838 Converted.push_back(TemplateArgument::CreatePackCopy(Context,
3839 ArgumentPack.data(),
3840 ArgumentPack.size()));
3841 ArgumentPack.clear();
3847 // Check whether we have a default argument.
3848 TemplateArgumentLoc Arg;
3850 // Retrieve the default template argument from the template
3851 // parameter. For each kind of template parameter, we substitute the
3852 // template arguments provided thus far and any "outer" template arguments
3853 // (when the template parameter was part of a nested template) into
3854 // the default argument.
3855 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*Param)) {
3856 if (!hasVisibleDefaultArgument(TTP))
3857 return diagnoseMissingArgument(*this, TemplateLoc, Template, TTP,
3860 TypeSourceInfo *ArgType = SubstDefaultTemplateArgument(*this,
3869 Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()),
3871 } else if (NonTypeTemplateParmDecl *NTTP
3872 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) {
3873 if (!hasVisibleDefaultArgument(NTTP))
3874 return diagnoseMissingArgument(*this, TemplateLoc, Template, NTTP,
3877 ExprResult E = SubstDefaultTemplateArgument(*this, Template,
3885 Expr *Ex = E.getAs<Expr>();
3886 Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex);
3888 TemplateTemplateParmDecl *TempParm
3889 = cast<TemplateTemplateParmDecl>(*Param);
3891 if (!hasVisibleDefaultArgument(TempParm))
3892 return diagnoseMissingArgument(*this, TemplateLoc, Template, TempParm,
3895 NestedNameSpecifierLoc QualifierLoc;
3896 TemplateName Name = SubstDefaultTemplateArgument(*this, Template,
3905 Arg = TemplateArgumentLoc(TemplateArgument(Name), QualifierLoc,
3906 TempParm->getDefaultArgument().getTemplateNameLoc());
3909 // Introduce an instantiation record that describes where we are using
3910 // the default template argument.
3911 InstantiatingTemplate Inst(*this, RAngleLoc, Template, *Param, Converted,
3912 SourceRange(TemplateLoc, RAngleLoc));
3913 if (Inst.isInvalid())
3916 // Check the default template argument.
3917 if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc,
3918 RAngleLoc, 0, Converted))
3921 // Core issue 150 (assumed resolution): if this is a template template
3922 // parameter, keep track of the default template arguments from the
3923 // template definition.
3924 if (isTemplateTemplateParameter)
3925 NewArgs.addArgument(Arg);
3927 // Move to the next template parameter and argument.
3932 // If we're performing a partial argument substitution, allow any trailing
3933 // pack expansions; they might be empty. This can happen even if
3934 // PartialTemplateArgs is false (the list of arguments is complete but
3935 // still dependent).
3936 if (ArgIdx < NumArgs && CurrentInstantiationScope &&
3937 CurrentInstantiationScope->getPartiallySubstitutedPack()) {
3938 while (ArgIdx < NumArgs && NewArgs[ArgIdx].getArgument().isPackExpansion())
3939 Converted.push_back(NewArgs[ArgIdx++].getArgument());
3942 // If we have any leftover arguments, then there were too many arguments.
3943 // Complain and fail.
3944 if (ArgIdx < NumArgs)
3945 return diagnoseArityMismatch(*this, Template, TemplateLoc, NewArgs);
3947 // No problems found with the new argument list, propagate changes back
3949 TemplateArgs = NewArgs;
3955 class UnnamedLocalNoLinkageFinder
3956 : public TypeVisitor<UnnamedLocalNoLinkageFinder, bool>
3961 typedef TypeVisitor<UnnamedLocalNoLinkageFinder, bool> inherited;
3964 UnnamedLocalNoLinkageFinder(Sema &S, SourceRange SR) : S(S), SR(SR) { }
3966 bool Visit(QualType T) {
3967 return inherited::Visit(T.getTypePtr());
3970 #define TYPE(Class, Parent) \
3971 bool Visit##Class##Type(const Class##Type *);
3972 #define ABSTRACT_TYPE(Class, Parent) \
3973 bool Visit##Class##Type(const Class##Type *) { return false; }
3974 #define NON_CANONICAL_TYPE(Class, Parent) \
3975 bool Visit##Class##Type(const Class##Type *) { return false; }
3976 #include "clang/AST/TypeNodes.def"
3978 bool VisitTagDecl(const TagDecl *Tag);
3979 bool VisitNestedNameSpecifier(NestedNameSpecifier *NNS);
3983 bool UnnamedLocalNoLinkageFinder::VisitBuiltinType(const BuiltinType*) {
3987 bool UnnamedLocalNoLinkageFinder::VisitComplexType(const ComplexType* T) {
3988 return Visit(T->getElementType());
3991 bool UnnamedLocalNoLinkageFinder::VisitPointerType(const PointerType* T) {
3992 return Visit(T->getPointeeType());
3995 bool UnnamedLocalNoLinkageFinder::VisitBlockPointerType(
3996 const BlockPointerType* T) {
3997 return Visit(T->getPointeeType());
4000 bool UnnamedLocalNoLinkageFinder::VisitLValueReferenceType(
4001 const LValueReferenceType* T) {
4002 return Visit(T->getPointeeType());
4005 bool UnnamedLocalNoLinkageFinder::VisitRValueReferenceType(
4006 const RValueReferenceType* T) {
4007 return Visit(T->getPointeeType());
4010 bool UnnamedLocalNoLinkageFinder::VisitMemberPointerType(
4011 const MemberPointerType* T) {
4012 return Visit(T->getPointeeType()) || Visit(QualType(T->getClass(), 0));
4015 bool UnnamedLocalNoLinkageFinder::VisitConstantArrayType(
4016 const ConstantArrayType* T) {
4017 return Visit(T->getElementType());
4020 bool UnnamedLocalNoLinkageFinder::VisitIncompleteArrayType(
4021 const IncompleteArrayType* T) {
4022 return Visit(T->getElementType());
4025 bool UnnamedLocalNoLinkageFinder::VisitVariableArrayType(
4026 const VariableArrayType* T) {
4027 return Visit(T->getElementType());
4030 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedArrayType(
4031 const DependentSizedArrayType* T) {
4032 return Visit(T->getElementType());
4035 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedExtVectorType(
4036 const DependentSizedExtVectorType* T) {
4037 return Visit(T->getElementType());
4040 bool UnnamedLocalNoLinkageFinder::VisitVectorType(const VectorType* T) {
4041 return Visit(T->getElementType());
4044 bool UnnamedLocalNoLinkageFinder::VisitExtVectorType(const ExtVectorType* T) {
4045 return Visit(T->getElementType());
4048 bool UnnamedLocalNoLinkageFinder::VisitFunctionProtoType(
4049 const FunctionProtoType* T) {
4050 for (const auto &A : T->param_types()) {
4055 return Visit(T->getReturnType());
4058 bool UnnamedLocalNoLinkageFinder::VisitFunctionNoProtoType(
4059 const FunctionNoProtoType* T) {
4060 return Visit(T->getReturnType());
4063 bool UnnamedLocalNoLinkageFinder::VisitUnresolvedUsingType(
4064 const UnresolvedUsingType*) {
4068 bool UnnamedLocalNoLinkageFinder::VisitTypeOfExprType(const TypeOfExprType*) {
4072 bool UnnamedLocalNoLinkageFinder::VisitTypeOfType(const TypeOfType* T) {
4073 return Visit(T->getUnderlyingType());
4076 bool UnnamedLocalNoLinkageFinder::VisitDecltypeType(const DecltypeType*) {
4080 bool UnnamedLocalNoLinkageFinder::VisitUnaryTransformType(
4081 const UnaryTransformType*) {
4085 bool UnnamedLocalNoLinkageFinder::VisitAutoType(const AutoType *T) {
4086 return Visit(T->getDeducedType());
4089 bool UnnamedLocalNoLinkageFinder::VisitRecordType(const RecordType* T) {
4090 return VisitTagDecl(T->getDecl());
4093 bool UnnamedLocalNoLinkageFinder::VisitEnumType(const EnumType* T) {
4094 return VisitTagDecl(T->getDecl());
4097 bool UnnamedLocalNoLinkageFinder::VisitTemplateTypeParmType(
4098 const TemplateTypeParmType*) {
4102 bool UnnamedLocalNoLinkageFinder::VisitSubstTemplateTypeParmPackType(
4103 const SubstTemplateTypeParmPackType *) {
4107 bool UnnamedLocalNoLinkageFinder::VisitTemplateSpecializationType(
4108 const TemplateSpecializationType*) {
4112 bool UnnamedLocalNoLinkageFinder::VisitInjectedClassNameType(
4113 const InjectedClassNameType* T) {
4114 return VisitTagDecl(T->getDecl());
4117 bool UnnamedLocalNoLinkageFinder::VisitDependentNameType(
4118 const DependentNameType* T) {
4119 return VisitNestedNameSpecifier(T->getQualifier());
4122 bool UnnamedLocalNoLinkageFinder::VisitDependentTemplateSpecializationType(
4123 const DependentTemplateSpecializationType* T) {
4124 return VisitNestedNameSpecifier(T->getQualifier());
4127 bool UnnamedLocalNoLinkageFinder::VisitPackExpansionType(
4128 const PackExpansionType* T) {
4129 return Visit(T->getPattern());
4132 bool UnnamedLocalNoLinkageFinder::VisitObjCObjectType(const ObjCObjectType *) {
4136 bool UnnamedLocalNoLinkageFinder::VisitObjCInterfaceType(
4137 const ObjCInterfaceType *) {
4141 bool UnnamedLocalNoLinkageFinder::VisitObjCObjectPointerType(
4142 const ObjCObjectPointerType *) {
4146 bool UnnamedLocalNoLinkageFinder::VisitAtomicType(const AtomicType* T) {
4147 return Visit(T->getValueType());
4150 bool UnnamedLocalNoLinkageFinder::VisitTagDecl(const TagDecl *Tag) {
4151 if (Tag->getDeclContext()->isFunctionOrMethod()) {
4152 S.Diag(SR.getBegin(),
4153 S.getLangOpts().CPlusPlus11 ?
4154 diag::warn_cxx98_compat_template_arg_local_type :
4155 diag::ext_template_arg_local_type)
4156 << S.Context.getTypeDeclType(Tag) << SR;
4160 if (!Tag->hasNameForLinkage()) {
4161 S.Diag(SR.getBegin(),
4162 S.getLangOpts().CPlusPlus11 ?
4163 diag::warn_cxx98_compat_template_arg_unnamed_type :
4164 diag::ext_template_arg_unnamed_type) << SR;
4165 S.Diag(Tag->getLocation(), diag::note_template_unnamed_type_here);
4172 bool UnnamedLocalNoLinkageFinder::VisitNestedNameSpecifier(
4173 NestedNameSpecifier *NNS) {
4174 if (NNS->getPrefix() && VisitNestedNameSpecifier(NNS->getPrefix()))
4177 switch (NNS->getKind()) {
4178 case NestedNameSpecifier::Identifier:
4179 case NestedNameSpecifier::Namespace:
4180 case NestedNameSpecifier::NamespaceAlias:
4181 case NestedNameSpecifier::Global:
4182 case NestedNameSpecifier::Super:
4185 case NestedNameSpecifier::TypeSpec:
4186 case NestedNameSpecifier::TypeSpecWithTemplate:
4187 return Visit(QualType(NNS->getAsType(), 0));
4189 llvm_unreachable("Invalid NestedNameSpecifier::Kind!");
4193 /// \brief Check a template argument against its corresponding
4194 /// template type parameter.
4196 /// This routine implements the semantics of C++ [temp.arg.type]. It
4197 /// returns true if an error occurred, and false otherwise.
4198 bool Sema::CheckTemplateArgument(TemplateTypeParmDecl *Param,
4199 TypeSourceInfo *ArgInfo) {
4200 assert(ArgInfo && "invalid TypeSourceInfo");
4201 QualType Arg = ArgInfo->getType();
4202 SourceRange SR = ArgInfo->getTypeLoc().getSourceRange();
4204 if (Arg->isVariablyModifiedType()) {
4205 return Diag(SR.getBegin(), diag::err_variably_modified_template_arg) << Arg;
4206 } else if (Context.hasSameUnqualifiedType(Arg, Context.OverloadTy)) {
4207 return Diag(SR.getBegin(), diag::err_template_arg_overload_type) << SR;
4210 // C++03 [temp.arg.type]p2:
4211 // A local type, a type with no linkage, an unnamed type or a type
4212 // compounded from any of these types shall not be used as a
4213 // template-argument for a template type-parameter.
4215 // C++11 allows these, and even in C++03 we allow them as an extension with
4218 if (LangOpts.CPlusPlus11)
4220 !Diags.isIgnored(diag::warn_cxx98_compat_template_arg_unnamed_type,
4222 !Diags.isIgnored(diag::warn_cxx98_compat_template_arg_local_type,
4225 NeedsCheck = Arg->hasUnnamedOrLocalType();
4228 UnnamedLocalNoLinkageFinder Finder(*this, SR);
4229 (void)Finder.Visit(Context.getCanonicalType(Arg));
4235 enum NullPointerValueKind {
4241 /// \brief Determine whether the given template argument is a null pointer
4242 /// value of the appropriate type.
4243 static NullPointerValueKind
4244 isNullPointerValueTemplateArgument(Sema &S, NonTypeTemplateParmDecl *Param,
4245 QualType ParamType, Expr *Arg) {
4246 if (Arg->isValueDependent() || Arg->isTypeDependent())
4247 return NPV_NotNullPointer;
4249 if (!S.getLangOpts().CPlusPlus11)
4250 return NPV_NotNullPointer;
4252 // Determine whether we have a constant expression.
4253 ExprResult ArgRV = S.DefaultFunctionArrayConversion(Arg);
4254 if (ArgRV.isInvalid())
4258 Expr::EvalResult EvalResult;
4259 SmallVector<PartialDiagnosticAt, 8> Notes;
4260 EvalResult.Diag = &Notes;
4261 if (!Arg->EvaluateAsRValue(EvalResult, S.Context) ||
4262 EvalResult.HasSideEffects) {
4263 SourceLocation DiagLoc = Arg->getExprLoc();
4265 // If our only note is the usual "invalid subexpression" note, just point
4266 // the caret at its location rather than producing an essentially
4268 if (Notes.size() == 1 && Notes[0].second.getDiagID() ==
4269 diag::note_invalid_subexpr_in_const_expr) {
4270 DiagLoc = Notes[0].first;
4274 S.Diag(DiagLoc, diag::err_template_arg_not_address_constant)
4275 << Arg->getType() << Arg->getSourceRange();
4276 for (unsigned I = 0, N = Notes.size(); I != N; ++I)
4277 S.Diag(Notes[I].first, Notes[I].second);
4279 S.Diag(Param->getLocation(), diag::note_template_param_here);
4283 // C++11 [temp.arg.nontype]p1:
4284 // - an address constant expression of type std::nullptr_t
4285 if (Arg->getType()->isNullPtrType())
4286 return NPV_NullPointer;
4288 // - a constant expression that evaluates to a null pointer value (4.10); or
4289 // - a constant expression that evaluates to a null member pointer value
4291 if ((EvalResult.Val.isLValue() && !EvalResult.Val.getLValueBase()) ||
4292 (EvalResult.Val.isMemberPointer() &&
4293 !EvalResult.Val.getMemberPointerDecl())) {
4294 // If our expression has an appropriate type, we've succeeded.
4295 bool ObjCLifetimeConversion;
4296 if (S.Context.hasSameUnqualifiedType(Arg->getType(), ParamType) ||
4297 S.IsQualificationConversion(Arg->getType(), ParamType, false,
4298 ObjCLifetimeConversion))
4299 return NPV_NullPointer;
4301 // The types didn't match, but we know we got a null pointer; complain,
4302 // then recover as if the types were correct.
4303 S.Diag(Arg->getExprLoc(), diag::err_template_arg_wrongtype_null_constant)
4304 << Arg->getType() << ParamType << Arg->getSourceRange();
4305 S.Diag(Param->getLocation(), diag::note_template_param_here);
4306 return NPV_NullPointer;
4309 // If we don't have a null pointer value, but we do have a NULL pointer
4310 // constant, suggest a cast to the appropriate type.
4311 if (Arg->isNullPointerConstant(S.Context, Expr::NPC_NeverValueDependent)) {
4312 std::string Code = "static_cast<" + ParamType.getAsString() + ">(";
4313 S.Diag(Arg->getExprLoc(), diag::err_template_arg_untyped_null_constant)
4314 << ParamType << FixItHint::CreateInsertion(Arg->getLocStart(), Code)
4315 << FixItHint::CreateInsertion(S.getLocForEndOfToken(Arg->getLocEnd()),
4317 S.Diag(Param->getLocation(), diag::note_template_param_here);
4318 return NPV_NullPointer;
4321 // FIXME: If we ever want to support general, address-constant expressions
4322 // as non-type template arguments, we should return the ExprResult here to
4323 // be interpreted by the caller.
4324 return NPV_NotNullPointer;
4327 /// \brief Checks whether the given template argument is compatible with its
4328 /// template parameter.
4329 static bool CheckTemplateArgumentIsCompatibleWithParameter(
4330 Sema &S, NonTypeTemplateParmDecl *Param, QualType ParamType, Expr *ArgIn,
4331 Expr *Arg, QualType ArgType) {
4332 bool ObjCLifetimeConversion;
4333 if (ParamType->isPointerType() &&
4334 !ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType() &&
4335 S.IsQualificationConversion(ArgType, ParamType, false,
4336 ObjCLifetimeConversion)) {
4337 // For pointer-to-object types, qualification conversions are
4340 if (const ReferenceType *ParamRef = ParamType->getAs<ReferenceType>()) {
4341 if (!ParamRef->getPointeeType()->isFunctionType()) {
4342 // C++ [temp.arg.nontype]p5b3:
4343 // For a non-type template-parameter of type reference to
4344 // object, no conversions apply. The type referred to by the
4345 // reference may be more cv-qualified than the (otherwise
4346 // identical) type of the template- argument. The
4347 // template-parameter is bound directly to the
4348 // template-argument, which shall be an lvalue.
4350 // FIXME: Other qualifiers?
4351 unsigned ParamQuals = ParamRef->getPointeeType().getCVRQualifiers();
4352 unsigned ArgQuals = ArgType.getCVRQualifiers();
4354 if ((ParamQuals | ArgQuals) != ParamQuals) {
4355 S.Diag(Arg->getLocStart(),
4356 diag::err_template_arg_ref_bind_ignores_quals)
4357 << ParamType << Arg->getType() << Arg->getSourceRange();
4358 S.Diag(Param->getLocation(), diag::note_template_param_here);
4364 // At this point, the template argument refers to an object or
4365 // function with external linkage. We now need to check whether the
4366 // argument and parameter types are compatible.
4367 if (!S.Context.hasSameUnqualifiedType(ArgType,
4368 ParamType.getNonReferenceType())) {
4369 // We can't perform this conversion or binding.
4370 if (ParamType->isReferenceType())
4371 S.Diag(Arg->getLocStart(), diag::err_template_arg_no_ref_bind)
4372 << ParamType << ArgIn->getType() << Arg->getSourceRange();
4374 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible)
4375 << ArgIn->getType() << ParamType << Arg->getSourceRange();
4376 S.Diag(Param->getLocation(), diag::note_template_param_here);
4384 /// \brief Checks whether the given template argument is the address
4385 /// of an object or function according to C++ [temp.arg.nontype]p1.
4387 CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S,
4388 NonTypeTemplateParmDecl *Param,
4391 TemplateArgument &Converted) {
4392 bool Invalid = false;
4394 QualType ArgType = Arg->getType();
4396 bool AddressTaken = false;
4397 SourceLocation AddrOpLoc;
4398 if (S.getLangOpts().MicrosoftExt) {
4399 // Microsoft Visual C++ strips all casts, allows an arbitrary number of
4400 // dereference and address-of operators.
4401 Arg = Arg->IgnoreParenCasts();
4403 bool ExtWarnMSTemplateArg = false;
4404 UnaryOperatorKind FirstOpKind;
4405 SourceLocation FirstOpLoc;
4406 while (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
4407 UnaryOperatorKind UnOpKind = UnOp->getOpcode();
4408 if (UnOpKind == UO_Deref)
4409 ExtWarnMSTemplateArg = true;
4410 if (UnOpKind == UO_AddrOf || UnOpKind == UO_Deref) {
4411 Arg = UnOp->getSubExpr()->IgnoreParenCasts();
4412 if (!AddrOpLoc.isValid()) {
4413 FirstOpKind = UnOpKind;
4414 FirstOpLoc = UnOp->getOperatorLoc();
4419 if (FirstOpLoc.isValid()) {
4420 if (ExtWarnMSTemplateArg)
4421 S.Diag(ArgIn->getLocStart(), diag::ext_ms_deref_template_argument)
4422 << ArgIn->getSourceRange();
4424 if (FirstOpKind == UO_AddrOf)
4425 AddressTaken = true;
4426 else if (Arg->getType()->isPointerType()) {
4427 // We cannot let pointers get dereferenced here, that is obviously not a
4428 // constant expression.
4429 assert(FirstOpKind == UO_Deref);
4430 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
4431 << Arg->getSourceRange();
4435 // See through any implicit casts we added to fix the type.
4436 Arg = Arg->IgnoreImpCasts();
4438 // C++ [temp.arg.nontype]p1:
4440 // A template-argument for a non-type, non-template
4441 // template-parameter shall be one of: [...]
4443 // -- the address of an object or function with external
4444 // linkage, including function templates and function
4445 // template-ids but excluding non-static class members,
4446 // expressed as & id-expression where the & is optional if
4447 // the name refers to a function or array, or if the
4448 // corresponding template-parameter is a reference; or
4450 // In C++98/03 mode, give an extension warning on any extra parentheses.
4451 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
4452 bool ExtraParens = false;
4453 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) {
4454 if (!Invalid && !ExtraParens) {
4455 S.Diag(Arg->getLocStart(),
4456 S.getLangOpts().CPlusPlus11
4457 ? diag::warn_cxx98_compat_template_arg_extra_parens
4458 : diag::ext_template_arg_extra_parens)
4459 << Arg->getSourceRange();
4463 Arg = Parens->getSubExpr();
4466 while (SubstNonTypeTemplateParmExpr *subst =
4467 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
4468 Arg = subst->getReplacement()->IgnoreImpCasts();
4470 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
4471 if (UnOp->getOpcode() == UO_AddrOf) {
4472 Arg = UnOp->getSubExpr();
4473 AddressTaken = true;
4474 AddrOpLoc = UnOp->getOperatorLoc();
4478 while (SubstNonTypeTemplateParmExpr *subst =
4479 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
4480 Arg = subst->getReplacement()->IgnoreImpCasts();
4483 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg);
4484 ValueDecl *Entity = DRE ? DRE->getDecl() : nullptr;
4486 // If our parameter has pointer type, check for a null template value.
4487 if (ParamType->isPointerType() || ParamType->isNullPtrType()) {
4488 NullPointerValueKind NPV;
4489 // dllimport'd entities aren't constant but are available inside of template
4491 if (Entity && Entity->hasAttr<DLLImportAttr>())
4492 NPV = NPV_NotNullPointer;
4494 NPV = isNullPointerValueTemplateArgument(S, Param, ParamType, ArgIn);
4496 case NPV_NullPointer:
4497 S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
4498 Converted = TemplateArgument(S.Context.getCanonicalType(ParamType),
4499 /*isNullPtr=*/true);
4505 case NPV_NotNullPointer:
4510 // Stop checking the precise nature of the argument if it is value dependent,
4511 // it should be checked when instantiated.
4512 if (Arg->isValueDependent()) {
4513 Converted = TemplateArgument(ArgIn);
4517 if (isa<CXXUuidofExpr>(Arg)) {
4518 if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType,
4519 ArgIn, Arg, ArgType))
4522 Converted = TemplateArgument(ArgIn);
4527 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
4528 << Arg->getSourceRange();
4529 S.Diag(Param->getLocation(), diag::note_template_param_here);
4533 // Cannot refer to non-static data members
4534 if (isa<FieldDecl>(Entity) || isa<IndirectFieldDecl>(Entity)) {
4535 S.Diag(Arg->getLocStart(), diag::err_template_arg_field)
4536 << Entity << Arg->getSourceRange();
4537 S.Diag(Param->getLocation(), diag::note_template_param_here);
4541 // Cannot refer to non-static member functions
4542 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Entity)) {
4543 if (!Method->isStatic()) {
4544 S.Diag(Arg->getLocStart(), diag::err_template_arg_method)
4545 << Method << Arg->getSourceRange();
4546 S.Diag(Param->getLocation(), diag::note_template_param_here);
4551 FunctionDecl *Func = dyn_cast<FunctionDecl>(Entity);
4552 VarDecl *Var = dyn_cast<VarDecl>(Entity);
4554 // A non-type template argument must refer to an object or function.
4555 if (!Func && !Var) {
4556 // We found something, but we don't know specifically what it is.
4557 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_object_or_func)
4558 << Arg->getSourceRange();
4559 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here);
4563 // Address / reference template args must have external linkage in C++98.
4564 if (Entity->getFormalLinkage() == InternalLinkage) {
4565 S.Diag(Arg->getLocStart(), S.getLangOpts().CPlusPlus11 ?
4566 diag::warn_cxx98_compat_template_arg_object_internal :
4567 diag::ext_template_arg_object_internal)
4568 << !Func << Entity << Arg->getSourceRange();
4569 S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
4571 } else if (!Entity->hasLinkage()) {
4572 S.Diag(Arg->getLocStart(), diag::err_template_arg_object_no_linkage)
4573 << !Func << Entity << Arg->getSourceRange();
4574 S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
4580 // If the template parameter has pointer type, the function decays.
4581 if (ParamType->isPointerType() && !AddressTaken)
4582 ArgType = S.Context.getPointerType(Func->getType());
4583 else if (AddressTaken && ParamType->isReferenceType()) {
4584 // If we originally had an address-of operator, but the
4585 // parameter has reference type, complain and (if things look
4586 // like they will work) drop the address-of operator.
4587 if (!S.Context.hasSameUnqualifiedType(Func->getType(),
4588 ParamType.getNonReferenceType())) {
4589 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4591 S.Diag(Param->getLocation(), diag::note_template_param_here);
4595 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4597 << FixItHint::CreateRemoval(AddrOpLoc);
4598 S.Diag(Param->getLocation(), diag::note_template_param_here);
4600 ArgType = Func->getType();
4603 // A value of reference type is not an object.
4604 if (Var->getType()->isReferenceType()) {
4605 S.Diag(Arg->getLocStart(),
4606 diag::err_template_arg_reference_var)
4607 << Var->getType() << Arg->getSourceRange();
4608 S.Diag(Param->getLocation(), diag::note_template_param_here);
4612 // A template argument must have static storage duration.
4613 if (Var->getTLSKind()) {
4614 S.Diag(Arg->getLocStart(), diag::err_template_arg_thread_local)
4615 << Arg->getSourceRange();
4616 S.Diag(Var->getLocation(), diag::note_template_arg_refers_here);
4620 // If the template parameter has pointer type, we must have taken
4621 // the address of this object.
4622 if (ParamType->isReferenceType()) {
4624 // If we originally had an address-of operator, but the
4625 // parameter has reference type, complain and (if things look
4626 // like they will work) drop the address-of operator.
4627 if (!S.Context.hasSameUnqualifiedType(Var->getType(),
4628 ParamType.getNonReferenceType())) {
4629 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4631 S.Diag(Param->getLocation(), diag::note_template_param_here);
4635 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4637 << FixItHint::CreateRemoval(AddrOpLoc);
4638 S.Diag(Param->getLocation(), diag::note_template_param_here);
4640 ArgType = Var->getType();
4642 } else if (!AddressTaken && ParamType->isPointerType()) {
4643 if (Var->getType()->isArrayType()) {
4644 // Array-to-pointer decay.
4645 ArgType = S.Context.getArrayDecayedType(Var->getType());
4647 // If the template parameter has pointer type but the address of
4648 // this object was not taken, complain and (possibly) recover by
4649 // taking the address of the entity.
4650 ArgType = S.Context.getPointerType(Var->getType());
4651 if (!S.Context.hasSameUnqualifiedType(ArgType, ParamType)) {
4652 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of)
4654 S.Diag(Param->getLocation(), diag::note_template_param_here);
4658 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of)
4660 << FixItHint::CreateInsertion(Arg->getLocStart(), "&");
4662 S.Diag(Param->getLocation(), diag::note_template_param_here);
4667 if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType, ArgIn,
4671 // Create the template argument.
4673 TemplateArgument(cast<ValueDecl>(Entity->getCanonicalDecl()), ParamType);
4674 S.MarkAnyDeclReferenced(Arg->getLocStart(), Entity, false);
4678 /// \brief Checks whether the given template argument is a pointer to
4679 /// member constant according to C++ [temp.arg.nontype]p1.
4680 static bool CheckTemplateArgumentPointerToMember(Sema &S,
4681 NonTypeTemplateParmDecl *Param,
4684 TemplateArgument &Converted) {
4685 bool Invalid = false;
4687 // Check for a null pointer value.
4688 Expr *Arg = ResultArg;
4689 switch (isNullPointerValueTemplateArgument(S, Param, ParamType, Arg)) {
4692 case NPV_NullPointer:
4693 S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
4694 Converted = TemplateArgument(S.Context.getCanonicalType(ParamType),
4696 if (S.Context.getTargetInfo().getCXXABI().isMicrosoft())
4697 S.RequireCompleteType(Arg->getExprLoc(), ParamType, 0);
4699 case NPV_NotNullPointer:
4703 bool ObjCLifetimeConversion;
4704 if (S.IsQualificationConversion(Arg->getType(),
4705 ParamType.getNonReferenceType(),
4706 false, ObjCLifetimeConversion)) {
4707 Arg = S.ImpCastExprToType(Arg, ParamType, CK_NoOp,
4708 Arg->getValueKind()).get();
4710 } else if (!S.Context.hasSameUnqualifiedType(Arg->getType(),
4711 ParamType.getNonReferenceType())) {
4712 // We can't perform this conversion.
4713 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible)
4714 << Arg->getType() << ParamType << Arg->getSourceRange();
4715 S.Diag(Param->getLocation(), diag::note_template_param_here);
4719 // See through any implicit casts we added to fix the type.
4720 while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg))
4721 Arg = Cast->getSubExpr();
4723 // C++ [temp.arg.nontype]p1:
4725 // A template-argument for a non-type, non-template
4726 // template-parameter shall be one of: [...]
4728 // -- a pointer to member expressed as described in 5.3.1.
4729 DeclRefExpr *DRE = nullptr;
4731 // In C++98/03 mode, give an extension warning on any extra parentheses.
4732 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
4733 bool ExtraParens = false;
4734 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) {
4735 if (!Invalid && !ExtraParens) {
4736 S.Diag(Arg->getLocStart(),
4737 S.getLangOpts().CPlusPlus11 ?
4738 diag::warn_cxx98_compat_template_arg_extra_parens :
4739 diag::ext_template_arg_extra_parens)
4740 << Arg->getSourceRange();
4744 Arg = Parens->getSubExpr();
4747 while (SubstNonTypeTemplateParmExpr *subst =
4748 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
4749 Arg = subst->getReplacement()->IgnoreImpCasts();
4751 // A pointer-to-member constant written &Class::member.
4752 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
4753 if (UnOp->getOpcode() == UO_AddrOf) {
4754 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr());
4755 if (DRE && !DRE->getQualifier())
4759 // A constant of pointer-to-member type.
4760 else if ((DRE = dyn_cast<DeclRefExpr>(Arg))) {
4761 if (ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl())) {
4762 if (VD->getType()->isMemberPointerType()) {
4763 if (isa<NonTypeTemplateParmDecl>(VD)) {
4764 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
4765 Converted = TemplateArgument(Arg);
4767 VD = cast<ValueDecl>(VD->getCanonicalDecl());
4768 Converted = TemplateArgument(VD, ParamType);
4779 return S.Diag(Arg->getLocStart(),
4780 diag::err_template_arg_not_pointer_to_member_form)
4781 << Arg->getSourceRange();
4783 if (isa<FieldDecl>(DRE->getDecl()) ||
4784 isa<IndirectFieldDecl>(DRE->getDecl()) ||
4785 isa<CXXMethodDecl>(DRE->getDecl())) {
4786 assert((isa<FieldDecl>(DRE->getDecl()) ||
4787 isa<IndirectFieldDecl>(DRE->getDecl()) ||
4788 !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) &&
4789 "Only non-static member pointers can make it here");
4791 // Okay: this is the address of a non-static member, and therefore
4792 // a member pointer constant.
4793 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
4794 Converted = TemplateArgument(Arg);
4796 ValueDecl *D = cast<ValueDecl>(DRE->getDecl()->getCanonicalDecl());
4797 Converted = TemplateArgument(D, ParamType);
4802 // We found something else, but we don't know specifically what it is.
4803 S.Diag(Arg->getLocStart(),
4804 diag::err_template_arg_not_pointer_to_member_form)
4805 << Arg->getSourceRange();
4806 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here);
4810 /// \brief Check a template argument against its corresponding
4811 /// non-type template parameter.
4813 /// This routine implements the semantics of C++ [temp.arg.nontype].
4814 /// If an error occurred, it returns ExprError(); otherwise, it
4815 /// returns the converted template argument. \p ParamType is the
4816 /// type of the non-type template parameter after it has been instantiated.
4817 ExprResult Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
4818 QualType ParamType, Expr *Arg,
4819 TemplateArgument &Converted,
4820 CheckTemplateArgumentKind CTAK) {
4821 SourceLocation StartLoc = Arg->getLocStart();
4823 // If either the parameter has a dependent type or the argument is
4824 // type-dependent, there's nothing we can check now.
4825 if (ParamType->isDependentType() || Arg->isTypeDependent()) {
4826 // FIXME: Produce a cloned, canonical expression?
4827 Converted = TemplateArgument(Arg);
4831 // We should have already dropped all cv-qualifiers by now.
4832 assert(!ParamType.hasQualifiers() &&
4833 "non-type template parameter type cannot be qualified");
4835 if (CTAK == CTAK_Deduced &&
4836 !Context.hasSameUnqualifiedType(ParamType, Arg->getType())) {
4837 // C++ [temp.deduct.type]p17:
4838 // If, in the declaration of a function template with a non-type
4839 // template-parameter, the non-type template-parameter is used
4840 // in an expression in the function parameter-list and, if the
4841 // corresponding template-argument is deduced, the
4842 // template-argument type shall match the type of the
4843 // template-parameter exactly, except that a template-argument
4844 // deduced from an array bound may be of any integral type.
4845 Diag(StartLoc, diag::err_deduced_non_type_template_arg_type_mismatch)
4846 << Arg->getType().getUnqualifiedType()
4847 << ParamType.getUnqualifiedType();
4848 Diag(Param->getLocation(), diag::note_template_param_here);
4852 if (getLangOpts().CPlusPlus1z) {
4853 // FIXME: We can do some limited checking for a value-dependent but not
4854 // type-dependent argument.
4855 if (Arg->isValueDependent()) {
4856 Converted = TemplateArgument(Arg);
4860 // C++1z [temp.arg.nontype]p1:
4861 // A template-argument for a non-type template parameter shall be
4862 // a converted constant expression of the type of the template-parameter.
4864 ExprResult ArgResult = CheckConvertedConstantExpression(
4865 Arg, ParamType, Value, CCEK_TemplateArg);
4866 if (ArgResult.isInvalid())
4869 QualType CanonParamType = Context.getCanonicalType(ParamType);
4871 // Convert the APValue to a TemplateArgument.
4872 switch (Value.getKind()) {
4873 case APValue::Uninitialized:
4874 assert(ParamType->isNullPtrType());
4875 Converted = TemplateArgument(CanonParamType, /*isNullPtr*/true);
4878 assert(ParamType->isIntegralOrEnumerationType());
4879 Converted = TemplateArgument(Context, Value.getInt(), CanonParamType);
4881 case APValue::MemberPointer: {
4882 assert(ParamType->isMemberPointerType());
4884 // FIXME: We need TemplateArgument representation and mangling for these.
4885 if (!Value.getMemberPointerPath().empty()) {
4886 Diag(Arg->getLocStart(),
4887 diag::err_template_arg_member_ptr_base_derived_not_supported)
4888 << Value.getMemberPointerDecl() << ParamType
4889 << Arg->getSourceRange();
4893 auto *VD = const_cast<ValueDecl*>(Value.getMemberPointerDecl());
4894 Converted = VD ? TemplateArgument(VD, CanonParamType)
4895 : TemplateArgument(CanonParamType, /*isNullPtr*/true);
4898 case APValue::LValue: {
4899 // For a non-type template-parameter of pointer or reference type,
4900 // the value of the constant expression shall not refer to
4901 assert(ParamType->isPointerType() || ParamType->isReferenceType() ||
4902 ParamType->isNullPtrType());
4903 // -- a temporary object
4904 // -- a string literal
4905 // -- the result of a typeid expression, or
4906 // -- a predefind __func__ variable
4907 if (auto *E = Value.getLValueBase().dyn_cast<const Expr*>()) {
4908 if (isa<CXXUuidofExpr>(E)) {
4909 Converted = TemplateArgument(const_cast<Expr*>(E));
4912 Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
4913 << Arg->getSourceRange();
4916 auto *VD = const_cast<ValueDecl *>(
4917 Value.getLValueBase().dyn_cast<const ValueDecl *>());
4919 if (Value.hasLValuePath() && Value.getLValuePath().size() == 1 &&
4920 VD && VD->getType()->isArrayType() &&
4921 Value.getLValuePath()[0].ArrayIndex == 0 &&
4922 !Value.isLValueOnePastTheEnd() && ParamType->isPointerType()) {
4923 // Per defect report (no number yet):
4924 // ... other than a pointer to the first element of a complete array
4926 } else if (!Value.hasLValuePath() || Value.getLValuePath().size() ||
4927 Value.isLValueOnePastTheEnd()) {
4928 Diag(StartLoc, diag::err_non_type_template_arg_subobject)
4929 << Value.getAsString(Context, ParamType);
4932 assert((VD || !ParamType->isReferenceType()) &&
4933 "null reference should not be a constant expression");
4934 assert((!VD || !ParamType->isNullPtrType()) &&
4935 "non-null value of type nullptr_t?");
4936 Converted = VD ? TemplateArgument(VD, CanonParamType)
4937 : TemplateArgument(CanonParamType, /*isNullPtr*/true);
4940 case APValue::AddrLabelDiff:
4941 return Diag(StartLoc, diag::err_non_type_template_arg_addr_label_diff);
4942 case APValue::Float:
4943 case APValue::ComplexInt:
4944 case APValue::ComplexFloat:
4945 case APValue::Vector:
4946 case APValue::Array:
4947 case APValue::Struct:
4948 case APValue::Union:
4949 llvm_unreachable("invalid kind for template argument");
4952 return ArgResult.get();
4955 // C++ [temp.arg.nontype]p5:
4956 // The following conversions are performed on each expression used
4957 // as a non-type template-argument. If a non-type
4958 // template-argument cannot be converted to the type of the
4959 // corresponding template-parameter then the program is
4961 if (ParamType->isIntegralOrEnumerationType()) {
4963 // -- for a non-type template-parameter of integral or
4964 // enumeration type, conversions permitted in a converted
4965 // constant expression are applied.
4968 // -- for a non-type template-parameter of integral or
4969 // enumeration type, integral promotions (4.5) and integral
4970 // conversions (4.7) are applied.
4972 if (getLangOpts().CPlusPlus11) {
4973 // We can't check arbitrary value-dependent arguments.
4974 // FIXME: If there's no viable conversion to the template parameter type,
4975 // we should be able to diagnose that prior to instantiation.
4976 if (Arg->isValueDependent()) {
4977 Converted = TemplateArgument(Arg);
4981 // C++ [temp.arg.nontype]p1:
4982 // A template-argument for a non-type, non-template template-parameter
4985 // -- for a non-type template-parameter of integral or enumeration
4986 // type, a converted constant expression of the type of the
4987 // template-parameter; or
4989 ExprResult ArgResult =
4990 CheckConvertedConstantExpression(Arg, ParamType, Value,
4992 if (ArgResult.isInvalid())
4995 // Widen the argument value to sizeof(parameter type). This is almost
4996 // always a no-op, except when the parameter type is bool. In
4997 // that case, this may extend the argument from 1 bit to 8 bits.
4998 QualType IntegerType = ParamType;
4999 if (const EnumType *Enum = IntegerType->getAs<EnumType>())
5000 IntegerType = Enum->getDecl()->getIntegerType();
5001 Value = Value.extOrTrunc(Context.getTypeSize(IntegerType));
5003 Converted = TemplateArgument(Context, Value,
5004 Context.getCanonicalType(ParamType));
5008 ExprResult ArgResult = DefaultLvalueConversion(Arg);
5009 if (ArgResult.isInvalid())
5011 Arg = ArgResult.get();
5013 QualType ArgType = Arg->getType();
5015 // C++ [temp.arg.nontype]p1:
5016 // A template-argument for a non-type, non-template
5017 // template-parameter shall be one of:
5019 // -- an integral constant-expression of integral or enumeration
5021 // -- the name of a non-type template-parameter; or
5022 SourceLocation NonConstantLoc;
5024 if (!ArgType->isIntegralOrEnumerationType()) {
5025 Diag(Arg->getLocStart(),
5026 diag::err_template_arg_not_integral_or_enumeral)
5027 << ArgType << Arg->getSourceRange();
5028 Diag(Param->getLocation(), diag::note_template_param_here);
5030 } else if (!Arg->isValueDependent()) {
5031 class TmplArgICEDiagnoser : public VerifyICEDiagnoser {
5035 TmplArgICEDiagnoser(QualType T) : T(T) { }
5037 void diagnoseNotICE(Sema &S, SourceLocation Loc,
5038 SourceRange SR) override {
5039 S.Diag(Loc, diag::err_template_arg_not_ice) << T << SR;
5041 } Diagnoser(ArgType);
5043 Arg = VerifyIntegerConstantExpression(Arg, &Value, Diagnoser,
5049 // From here on out, all we care about is the unqualified form
5050 // of the argument type.
5051 ArgType = ArgType.getUnqualifiedType();
5053 // Try to convert the argument to the parameter's type.
5054 if (Context.hasSameType(ParamType, ArgType)) {
5055 // Okay: no conversion necessary
5056 } else if (ParamType->isBooleanType()) {
5057 // This is an integral-to-boolean conversion.
5058 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralToBoolean).get();
5059 } else if (IsIntegralPromotion(Arg, ArgType, ParamType) ||
5060 !ParamType->isEnumeralType()) {
5061 // This is an integral promotion or conversion.
5062 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralCast).get();
5064 // We can't perform this conversion.
5065 Diag(Arg->getLocStart(),
5066 diag::err_template_arg_not_convertible)
5067 << Arg->getType() << ParamType << Arg->getSourceRange();
5068 Diag(Param->getLocation(), diag::note_template_param_here);
5072 // Add the value of this argument to the list of converted
5073 // arguments. We use the bitwidth and signedness of the template
5075 if (Arg->isValueDependent()) {
5076 // The argument is value-dependent. Create a new
5077 // TemplateArgument with the converted expression.
5078 Converted = TemplateArgument(Arg);
5082 QualType IntegerType = Context.getCanonicalType(ParamType);
5083 if (const EnumType *Enum = IntegerType->getAs<EnumType>())
5084 IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType());
5086 if (ParamType->isBooleanType()) {
5087 // Value must be zero or one.
5089 unsigned AllowedBits = Context.getTypeSize(IntegerType);
5090 if (Value.getBitWidth() != AllowedBits)
5091 Value = Value.extOrTrunc(AllowedBits);
5092 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
5094 llvm::APSInt OldValue = Value;
5096 // Coerce the template argument's value to the value it will have
5097 // based on the template parameter's type.
5098 unsigned AllowedBits = Context.getTypeSize(IntegerType);
5099 if (Value.getBitWidth() != AllowedBits)
5100 Value = Value.extOrTrunc(AllowedBits);
5101 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
5103 // Complain if an unsigned parameter received a negative value.
5104 if (IntegerType->isUnsignedIntegerOrEnumerationType()
5105 && (OldValue.isSigned() && OldValue.isNegative())) {
5106 Diag(Arg->getLocStart(), diag::warn_template_arg_negative)
5107 << OldValue.toString(10) << Value.toString(10) << Param->getType()
5108 << Arg->getSourceRange();
5109 Diag(Param->getLocation(), diag::note_template_param_here);
5112 // Complain if we overflowed the template parameter's type.
5113 unsigned RequiredBits;
5114 if (IntegerType->isUnsignedIntegerOrEnumerationType())
5115 RequiredBits = OldValue.getActiveBits();
5116 else if (OldValue.isUnsigned())
5117 RequiredBits = OldValue.getActiveBits() + 1;
5119 RequiredBits = OldValue.getMinSignedBits();
5120 if (RequiredBits > AllowedBits) {
5121 Diag(Arg->getLocStart(),
5122 diag::warn_template_arg_too_large)
5123 << OldValue.toString(10) << Value.toString(10) << Param->getType()
5124 << Arg->getSourceRange();
5125 Diag(Param->getLocation(), diag::note_template_param_here);
5129 Converted = TemplateArgument(Context, Value,
5130 ParamType->isEnumeralType()
5131 ? Context.getCanonicalType(ParamType)
5136 QualType ArgType = Arg->getType();
5137 DeclAccessPair FoundResult; // temporary for ResolveOverloadedFunction
5139 // Handle pointer-to-function, reference-to-function, and
5140 // pointer-to-member-function all in (roughly) the same way.
5141 if (// -- For a non-type template-parameter of type pointer to
5142 // function, only the function-to-pointer conversion (4.3) is
5143 // applied. If the template-argument represents a set of
5144 // overloaded functions (or a pointer to such), the matching
5145 // function is selected from the set (13.4).
5146 (ParamType->isPointerType() &&
5147 ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType()) ||
5148 // -- For a non-type template-parameter of type reference to
5149 // function, no conversions apply. If the template-argument
5150 // represents a set of overloaded functions, the matching
5151 // function is selected from the set (13.4).
5152 (ParamType->isReferenceType() &&
5153 ParamType->getAs<ReferenceType>()->getPointeeType()->isFunctionType()) ||
5154 // -- For a non-type template-parameter of type pointer to
5155 // member function, no conversions apply. If the
5156 // template-argument represents a set of overloaded member
5157 // functions, the matching member function is selected from
5159 (ParamType->isMemberPointerType() &&
5160 ParamType->getAs<MemberPointerType>()->getPointeeType()
5161 ->isFunctionType())) {
5163 if (Arg->getType() == Context.OverloadTy) {
5164 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType,
5167 if (DiagnoseUseOfDecl(Fn, Arg->getLocStart()))
5170 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
5171 ArgType = Arg->getType();
5176 if (!ParamType->isMemberPointerType()) {
5177 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5184 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
5190 if (ParamType->isPointerType()) {
5191 // -- for a non-type template-parameter of type pointer to
5192 // object, qualification conversions (4.4) and the
5193 // array-to-pointer conversion (4.2) are applied.
5194 // C++0x also allows a value of std::nullptr_t.
5195 assert(ParamType->getPointeeType()->isIncompleteOrObjectType() &&
5196 "Only object pointers allowed here");
5198 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5205 if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) {
5206 // -- For a non-type template-parameter of type reference to
5207 // object, no conversions apply. The type referred to by the
5208 // reference may be more cv-qualified than the (otherwise
5209 // identical) type of the template-argument. The
5210 // template-parameter is bound directly to the
5211 // template-argument, which must be an lvalue.
5212 assert(ParamRefType->getPointeeType()->isIncompleteOrObjectType() &&
5213 "Only object references allowed here");
5215 if (Arg->getType() == Context.OverloadTy) {
5216 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg,
5217 ParamRefType->getPointeeType(),
5220 if (DiagnoseUseOfDecl(Fn, Arg->getLocStart()))
5223 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
5224 ArgType = Arg->getType();
5229 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5236 // Deal with parameters of type std::nullptr_t.
5237 if (ParamType->isNullPtrType()) {
5238 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
5239 Converted = TemplateArgument(Arg);
5243 switch (isNullPointerValueTemplateArgument(*this, Param, ParamType, Arg)) {
5244 case NPV_NotNullPointer:
5245 Diag(Arg->getExprLoc(), diag::err_template_arg_not_convertible)
5246 << Arg->getType() << ParamType;
5247 Diag(Param->getLocation(), diag::note_template_param_here);
5253 case NPV_NullPointer:
5254 Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
5255 Converted = TemplateArgument(Context.getCanonicalType(ParamType),
5261 // -- For a non-type template-parameter of type pointer to data
5262 // member, qualification conversions (4.4) are applied.
5263 assert(ParamType->isMemberPointerType() && "Only pointers to members remain");
5265 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
5271 /// \brief Check a template argument against its corresponding
5272 /// template template parameter.
5274 /// This routine implements the semantics of C++ [temp.arg.template].
5275 /// It returns true if an error occurred, and false otherwise.
5276 bool Sema::CheckTemplateArgument(TemplateTemplateParmDecl *Param,
5277 TemplateArgumentLoc &Arg,
5278 unsigned ArgumentPackIndex) {
5279 TemplateName Name = Arg.getArgument().getAsTemplateOrTemplatePattern();
5280 TemplateDecl *Template = Name.getAsTemplateDecl();
5282 // Any dependent template name is fine.
5283 assert(Name.isDependent() && "Non-dependent template isn't a declaration?");
5287 // C++0x [temp.arg.template]p1:
5288 // A template-argument for a template template-parameter shall be
5289 // the name of a class template or an alias template, expressed as an
5290 // id-expression. When the template-argument names a class template, only
5291 // primary class templates are considered when matching the
5292 // template template argument with the corresponding parameter;
5293 // partial specializations are not considered even if their
5294 // parameter lists match that of the template template parameter.
5296 // Note that we also allow template template parameters here, which
5297 // will happen when we are dealing with, e.g., class template
5298 // partial specializations.
5299 if (!isa<ClassTemplateDecl>(Template) &&
5300 !isa<TemplateTemplateParmDecl>(Template) &&
5301 !isa<TypeAliasTemplateDecl>(Template)) {
5302 assert(isa<FunctionTemplateDecl>(Template) &&
5303 "Only function templates are possible here");
5304 Diag(Arg.getLocation(), diag::err_template_arg_not_class_template);
5305 Diag(Template->getLocation(), diag::note_template_arg_refers_here_func)
5309 TemplateParameterList *Params = Param->getTemplateParameters();
5310 if (Param->isExpandedParameterPack())
5311 Params = Param->getExpansionTemplateParameters(ArgumentPackIndex);
5313 return !TemplateParameterListsAreEqual(Template->getTemplateParameters(),
5316 TPL_TemplateTemplateArgumentMatch,
5320 /// \brief Given a non-type template argument that refers to a
5321 /// declaration and the type of its corresponding non-type template
5322 /// parameter, produce an expression that properly refers to that
5325 Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
5327 SourceLocation Loc) {
5328 // C++ [temp.param]p8:
5330 // A non-type template-parameter of type "array of T" or
5331 // "function returning T" is adjusted to be of type "pointer to
5332 // T" or "pointer to function returning T", respectively.
5333 if (ParamType->isArrayType())
5334 ParamType = Context.getArrayDecayedType(ParamType);
5335 else if (ParamType->isFunctionType())
5336 ParamType = Context.getPointerType(ParamType);
5338 // For a NULL non-type template argument, return nullptr casted to the
5339 // parameter's type.
5340 if (Arg.getKind() == TemplateArgument::NullPtr) {
5341 return ImpCastExprToType(
5342 new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc),
5344 ParamType->getAs<MemberPointerType>()
5345 ? CK_NullToMemberPointer
5346 : CK_NullToPointer);
5348 assert(Arg.getKind() == TemplateArgument::Declaration &&
5349 "Only declaration template arguments permitted here");
5351 ValueDecl *VD = cast<ValueDecl>(Arg.getAsDecl());
5353 if (VD->getDeclContext()->isRecord() &&
5354 (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD) ||
5355 isa<IndirectFieldDecl>(VD))) {
5356 // If the value is a class member, we might have a pointer-to-member.
5357 // Determine whether the non-type template template parameter is of
5358 // pointer-to-member type. If so, we need to build an appropriate
5359 // expression for a pointer-to-member, since a "normal" DeclRefExpr
5360 // would refer to the member itself.
5361 if (ParamType->isMemberPointerType()) {
5363 = Context.getTypeDeclType(cast<RecordDecl>(VD->getDeclContext()));
5364 NestedNameSpecifier *Qualifier
5365 = NestedNameSpecifier::Create(Context, nullptr, false,
5366 ClassType.getTypePtr());
5368 SS.MakeTrivial(Context, Qualifier, Loc);
5370 // The actual value-ness of this is unimportant, but for
5371 // internal consistency's sake, references to instance methods
5373 ExprValueKind VK = VK_LValue;
5374 if (isa<CXXMethodDecl>(VD) && cast<CXXMethodDecl>(VD)->isInstance())
5377 ExprResult RefExpr = BuildDeclRefExpr(VD,
5378 VD->getType().getNonReferenceType(),
5382 if (RefExpr.isInvalid())
5385 RefExpr = CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
5387 // We might need to perform a trailing qualification conversion, since
5388 // the element type on the parameter could be more qualified than the
5389 // element type in the expression we constructed.
5390 bool ObjCLifetimeConversion;
5391 if (IsQualificationConversion(((Expr*) RefExpr.get())->getType(),
5392 ParamType.getUnqualifiedType(), false,
5393 ObjCLifetimeConversion))
5394 RefExpr = ImpCastExprToType(RefExpr.get(), ParamType.getUnqualifiedType(), CK_NoOp);
5396 assert(!RefExpr.isInvalid() &&
5397 Context.hasSameType(((Expr*) RefExpr.get())->getType(),
5398 ParamType.getUnqualifiedType()));
5403 QualType T = VD->getType().getNonReferenceType();
5405 if (ParamType->isPointerType()) {
5406 // When the non-type template parameter is a pointer, take the
5407 // address of the declaration.
5408 ExprResult RefExpr = BuildDeclRefExpr(VD, T, VK_LValue, Loc);
5409 if (RefExpr.isInvalid())
5412 if (T->isFunctionType() || T->isArrayType()) {
5413 // Decay functions and arrays.
5414 RefExpr = DefaultFunctionArrayConversion(RefExpr.get());
5415 if (RefExpr.isInvalid())
5421 // Take the address of everything else
5422 return CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
5425 ExprValueKind VK = VK_RValue;
5427 // If the non-type template parameter has reference type, qualify the
5428 // resulting declaration reference with the extra qualifiers on the
5429 // type that the reference refers to.
5430 if (const ReferenceType *TargetRef = ParamType->getAs<ReferenceType>()) {
5432 T = Context.getQualifiedType(T,
5433 TargetRef->getPointeeType().getQualifiers());
5434 } else if (isa<FunctionDecl>(VD)) {
5435 // References to functions are always lvalues.
5439 return BuildDeclRefExpr(VD, T, VK, Loc);
5442 /// \brief Construct a new expression that refers to the given
5443 /// integral template argument with the given source-location
5446 /// This routine takes care of the mapping from an integral template
5447 /// argument (which may have any integral type) to the appropriate
5450 Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg,
5451 SourceLocation Loc) {
5452 assert(Arg.getKind() == TemplateArgument::Integral &&
5453 "Operation is only valid for integral template arguments");
5454 QualType OrigT = Arg.getIntegralType();
5456 // If this is an enum type that we're instantiating, we need to use an integer
5457 // type the same size as the enumerator. We don't want to build an
5458 // IntegerLiteral with enum type. The integer type of an enum type can be of
5459 // any integral type with C++11 enum classes, make sure we create the right
5460 // type of literal for it.
5462 if (const EnumType *ET = OrigT->getAs<EnumType>())
5463 T = ET->getDecl()->getIntegerType();
5466 if (T->isAnyCharacterType()) {
5467 CharacterLiteral::CharacterKind Kind;
5468 if (T->isWideCharType())
5469 Kind = CharacterLiteral::Wide;
5470 else if (T->isChar16Type())
5471 Kind = CharacterLiteral::UTF16;
5472 else if (T->isChar32Type())
5473 Kind = CharacterLiteral::UTF32;
5475 Kind = CharacterLiteral::Ascii;
5477 E = new (Context) CharacterLiteral(Arg.getAsIntegral().getZExtValue(),
5479 } else if (T->isBooleanType()) {
5480 E = new (Context) CXXBoolLiteralExpr(Arg.getAsIntegral().getBoolValue(),
5482 } else if (T->isNullPtrType()) {
5483 E = new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
5485 E = IntegerLiteral::Create(Context, Arg.getAsIntegral(), T, Loc);
5488 if (OrigT->isEnumeralType()) {
5489 // FIXME: This is a hack. We need a better way to handle substituted
5490 // non-type template parameters.
5491 E = CStyleCastExpr::Create(Context, OrigT, VK_RValue, CK_IntegralCast, E,
5493 Context.getTrivialTypeSourceInfo(OrigT, Loc),
5500 /// \brief Match two template parameters within template parameter lists.
5501 static bool MatchTemplateParameterKind(Sema &S, NamedDecl *New, NamedDecl *Old,
5503 Sema::TemplateParameterListEqualKind Kind,
5504 SourceLocation TemplateArgLoc) {
5505 // Check the actual kind (type, non-type, template).
5506 if (Old->getKind() != New->getKind()) {
5508 unsigned NextDiag = diag::err_template_param_different_kind;
5509 if (TemplateArgLoc.isValid()) {
5510 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
5511 NextDiag = diag::note_template_param_different_kind;
5513 S.Diag(New->getLocation(), NextDiag)
5514 << (Kind != Sema::TPL_TemplateMatch);
5515 S.Diag(Old->getLocation(), diag::note_template_prev_declaration)
5516 << (Kind != Sema::TPL_TemplateMatch);
5522 // Check that both are parameter packs are neither are parameter packs.
5523 // However, if we are matching a template template argument to a
5524 // template template parameter, the template template parameter can have
5525 // a parameter pack where the template template argument does not.
5526 if (Old->isTemplateParameterPack() != New->isTemplateParameterPack() &&
5527 !(Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
5528 Old->isTemplateParameterPack())) {
5530 unsigned NextDiag = diag::err_template_parameter_pack_non_pack;
5531 if (TemplateArgLoc.isValid()) {
5532 S.Diag(TemplateArgLoc,
5533 diag::err_template_arg_template_params_mismatch);
5534 NextDiag = diag::note_template_parameter_pack_non_pack;
5537 unsigned ParamKind = isa<TemplateTypeParmDecl>(New)? 0
5538 : isa<NonTypeTemplateParmDecl>(New)? 1
5540 S.Diag(New->getLocation(), NextDiag)
5541 << ParamKind << New->isParameterPack();
5542 S.Diag(Old->getLocation(), diag::note_template_parameter_pack_here)
5543 << ParamKind << Old->isParameterPack();
5549 // For non-type template parameters, check the type of the parameter.
5550 if (NonTypeTemplateParmDecl *OldNTTP
5551 = dyn_cast<NonTypeTemplateParmDecl>(Old)) {
5552 NonTypeTemplateParmDecl *NewNTTP = cast<NonTypeTemplateParmDecl>(New);
5554 // If we are matching a template template argument to a template
5555 // template parameter and one of the non-type template parameter types
5556 // is dependent, then we must wait until template instantiation time
5557 // to actually compare the arguments.
5558 if (Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
5559 (OldNTTP->getType()->isDependentType() ||
5560 NewNTTP->getType()->isDependentType()))
5563 if (!S.Context.hasSameType(OldNTTP->getType(), NewNTTP->getType())) {
5565 unsigned NextDiag = diag::err_template_nontype_parm_different_type;
5566 if (TemplateArgLoc.isValid()) {
5567 S.Diag(TemplateArgLoc,
5568 diag::err_template_arg_template_params_mismatch);
5569 NextDiag = diag::note_template_nontype_parm_different_type;
5571 S.Diag(NewNTTP->getLocation(), NextDiag)
5572 << NewNTTP->getType()
5573 << (Kind != Sema::TPL_TemplateMatch);
5574 S.Diag(OldNTTP->getLocation(),
5575 diag::note_template_nontype_parm_prev_declaration)
5576 << OldNTTP->getType();
5585 // For template template parameters, check the template parameter types.
5586 // The template parameter lists of template template
5587 // parameters must agree.
5588 if (TemplateTemplateParmDecl *OldTTP
5589 = dyn_cast<TemplateTemplateParmDecl>(Old)) {
5590 TemplateTemplateParmDecl *NewTTP = cast<TemplateTemplateParmDecl>(New);
5591 return S.TemplateParameterListsAreEqual(NewTTP->getTemplateParameters(),
5592 OldTTP->getTemplateParameters(),
5594 (Kind == Sema::TPL_TemplateMatch
5595 ? Sema::TPL_TemplateTemplateParmMatch
5603 /// \brief Diagnose a known arity mismatch when comparing template argument
5606 void DiagnoseTemplateParameterListArityMismatch(Sema &S,
5607 TemplateParameterList *New,
5608 TemplateParameterList *Old,
5609 Sema::TemplateParameterListEqualKind Kind,
5610 SourceLocation TemplateArgLoc) {
5611 unsigned NextDiag = diag::err_template_param_list_different_arity;
5612 if (TemplateArgLoc.isValid()) {
5613 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
5614 NextDiag = diag::note_template_param_list_different_arity;
5616 S.Diag(New->getTemplateLoc(), NextDiag)
5617 << (New->size() > Old->size())
5618 << (Kind != Sema::TPL_TemplateMatch)
5619 << SourceRange(New->getTemplateLoc(), New->getRAngleLoc());
5620 S.Diag(Old->getTemplateLoc(), diag::note_template_prev_declaration)
5621 << (Kind != Sema::TPL_TemplateMatch)
5622 << SourceRange(Old->getTemplateLoc(), Old->getRAngleLoc());
5625 /// \brief Determine whether the given template parameter lists are
5628 /// \param New The new template parameter list, typically written in the
5629 /// source code as part of a new template declaration.
5631 /// \param Old The old template parameter list, typically found via
5632 /// name lookup of the template declared with this template parameter
5635 /// \param Complain If true, this routine will produce a diagnostic if
5636 /// the template parameter lists are not equivalent.
5638 /// \param Kind describes how we are to match the template parameter lists.
5640 /// \param TemplateArgLoc If this source location is valid, then we
5641 /// are actually checking the template parameter list of a template
5642 /// argument (New) against the template parameter list of its
5643 /// corresponding template template parameter (Old). We produce
5644 /// slightly different diagnostics in this scenario.
5646 /// \returns True if the template parameter lists are equal, false
5649 Sema::TemplateParameterListsAreEqual(TemplateParameterList *New,
5650 TemplateParameterList *Old,
5652 TemplateParameterListEqualKind Kind,
5653 SourceLocation TemplateArgLoc) {
5654 if (Old->size() != New->size() && Kind != TPL_TemplateTemplateArgumentMatch) {
5656 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
5662 // C++0x [temp.arg.template]p3:
5663 // A template-argument matches a template template-parameter (call it P)
5664 // when each of the template parameters in the template-parameter-list of
5665 // the template-argument's corresponding class template or alias template
5666 // (call it A) matches the corresponding template parameter in the
5667 // template-parameter-list of P. [...]
5668 TemplateParameterList::iterator NewParm = New->begin();
5669 TemplateParameterList::iterator NewParmEnd = New->end();
5670 for (TemplateParameterList::iterator OldParm = Old->begin(),
5671 OldParmEnd = Old->end();
5672 OldParm != OldParmEnd; ++OldParm) {
5673 if (Kind != TPL_TemplateTemplateArgumentMatch ||
5674 !(*OldParm)->isTemplateParameterPack()) {
5675 if (NewParm == NewParmEnd) {
5677 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
5683 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
5684 Kind, TemplateArgLoc))
5691 // C++0x [temp.arg.template]p3:
5692 // [...] When P's template- parameter-list contains a template parameter
5693 // pack (14.5.3), the template parameter pack will match zero or more
5694 // template parameters or template parameter packs in the
5695 // template-parameter-list of A with the same type and form as the
5696 // template parameter pack in P (ignoring whether those template
5697 // parameters are template parameter packs).
5698 for (; NewParm != NewParmEnd; ++NewParm) {
5699 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
5700 Kind, TemplateArgLoc))
5705 // Make sure we exhausted all of the arguments.
5706 if (NewParm != NewParmEnd) {
5708 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
5717 /// \brief Check whether a template can be declared within this scope.
5719 /// If the template declaration is valid in this scope, returns
5720 /// false. Otherwise, issues a diagnostic and returns true.
5722 Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) {
5726 // Find the nearest enclosing declaration scope.
5727 while ((S->getFlags() & Scope::DeclScope) == 0 ||
5728 (S->getFlags() & Scope::TemplateParamScope) != 0)
5732 // A template [...] shall not have C linkage.
5733 DeclContext *Ctx = S->getEntity();
5734 if (Ctx && Ctx->isExternCContext())
5735 return Diag(TemplateParams->getTemplateLoc(), diag::err_template_linkage)
5736 << TemplateParams->getSourceRange();
5738 while (Ctx && isa<LinkageSpecDecl>(Ctx))
5739 Ctx = Ctx->getParent();
5742 // A template-declaration can appear only as a namespace scope or
5743 // class scope declaration.
5745 if (Ctx->isFileContext())
5747 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Ctx)) {
5748 // C++ [temp.mem]p2:
5749 // A local class shall not have member templates.
5750 if (RD->isLocalClass())
5751 return Diag(TemplateParams->getTemplateLoc(),
5752 diag::err_template_inside_local_class)
5753 << TemplateParams->getSourceRange();
5759 return Diag(TemplateParams->getTemplateLoc(),
5760 diag::err_template_outside_namespace_or_class_scope)
5761 << TemplateParams->getSourceRange();
5764 /// \brief Determine what kind of template specialization the given declaration
5766 static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D) {
5768 return TSK_Undeclared;
5770 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D))
5771 return Record->getTemplateSpecializationKind();
5772 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D))
5773 return Function->getTemplateSpecializationKind();
5774 if (VarDecl *Var = dyn_cast<VarDecl>(D))
5775 return Var->getTemplateSpecializationKind();
5777 return TSK_Undeclared;
5780 /// \brief Check whether a specialization is well-formed in the current
5783 /// This routine determines whether a template specialization can be declared
5784 /// in the current context (C++ [temp.expl.spec]p2).
5786 /// \param S the semantic analysis object for which this check is being
5789 /// \param Specialized the entity being specialized or instantiated, which
5790 /// may be a kind of template (class template, function template, etc.) or
5791 /// a member of a class template (member function, static data member,
5794 /// \param PrevDecl the previous declaration of this entity, if any.
5796 /// \param Loc the location of the explicit specialization or instantiation of
5799 /// \param IsPartialSpecialization whether this is a partial specialization of
5800 /// a class template.
5802 /// \returns true if there was an error that we cannot recover from, false
5804 static bool CheckTemplateSpecializationScope(Sema &S,
5805 NamedDecl *Specialized,
5806 NamedDecl *PrevDecl,
5808 bool IsPartialSpecialization) {
5809 // Keep these "kind" numbers in sync with the %select statements in the
5810 // various diagnostics emitted by this routine.
5812 if (isa<ClassTemplateDecl>(Specialized))
5813 EntityKind = IsPartialSpecialization? 1 : 0;
5814 else if (isa<VarTemplateDecl>(Specialized))
5815 EntityKind = IsPartialSpecialization ? 3 : 2;
5816 else if (isa<FunctionTemplateDecl>(Specialized))
5818 else if (isa<CXXMethodDecl>(Specialized))
5820 else if (isa<VarDecl>(Specialized))
5822 else if (isa<RecordDecl>(Specialized))
5824 else if (isa<EnumDecl>(Specialized) && S.getLangOpts().CPlusPlus11)
5827 S.Diag(Loc, diag::err_template_spec_unknown_kind)
5828 << S.getLangOpts().CPlusPlus11;
5829 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
5833 // C++ [temp.expl.spec]p2:
5834 // An explicit specialization shall be declared in the namespace
5835 // of which the template is a member, or, for member templates, in
5836 // the namespace of which the enclosing class or enclosing class
5837 // template is a member. An explicit specialization of a member
5838 // function, member class or static data member of a class
5839 // template shall be declared in the namespace of which the class
5840 // template is a member. Such a declaration may also be a
5841 // definition. If the declaration is not a definition, the
5842 // specialization may be defined later in the name- space in which
5843 // the explicit specialization was declared, or in a namespace
5844 // that encloses the one in which the explicit specialization was
5846 if (S.CurContext->getRedeclContext()->isFunctionOrMethod()) {
5847 S.Diag(Loc, diag::err_template_spec_decl_function_scope)
5852 if (S.CurContext->isRecord() && !IsPartialSpecialization) {
5853 if (S.getLangOpts().MicrosoftExt) {
5854 // Do not warn for class scope explicit specialization during
5855 // instantiation, warning was already emitted during pattern
5856 // semantic analysis.
5857 if (!S.ActiveTemplateInstantiations.size())
5858 S.Diag(Loc, diag::ext_function_specialization_in_class)
5861 S.Diag(Loc, diag::err_template_spec_decl_class_scope)
5867 if (S.CurContext->isRecord() &&
5868 !S.CurContext->Equals(Specialized->getDeclContext())) {
5869 // Make sure that we're specializing in the right record context.
5870 // Otherwise, things can go horribly wrong.
5871 S.Diag(Loc, diag::err_template_spec_decl_class_scope)
5876 // C++ [temp.class.spec]p6:
5877 // A class template partial specialization may be declared or redeclared
5878 // in any namespace scope in which its definition may be defined (14.5.1
5880 DeclContext *SpecializedContext
5881 = Specialized->getDeclContext()->getEnclosingNamespaceContext();
5882 DeclContext *DC = S.CurContext->getEnclosingNamespaceContext();
5884 // Make sure that this redeclaration (or definition) occurs in an enclosing
5886 // Note that HandleDeclarator() performs this check for explicit
5887 // specializations of function templates, static data members, and member
5888 // functions, so we skip the check here for those kinds of entities.
5889 // FIXME: HandleDeclarator's diagnostics aren't quite as good, though.
5890 // Should we refactor that check, so that it occurs later?
5891 if (!DC->Encloses(SpecializedContext) &&
5892 !(isa<FunctionTemplateDecl>(Specialized) ||
5893 isa<FunctionDecl>(Specialized) ||
5894 isa<VarTemplateDecl>(Specialized) ||
5895 isa<VarDecl>(Specialized))) {
5896 if (isa<TranslationUnitDecl>(SpecializedContext))
5897 S.Diag(Loc, diag::err_template_spec_redecl_global_scope)
5898 << EntityKind << Specialized;
5899 else if (isa<NamespaceDecl>(SpecializedContext)) {
5900 int Diag = diag::err_template_spec_redecl_out_of_scope;
5901 if (S.getLangOpts().MicrosoftExt)
5902 Diag = diag::ext_ms_template_spec_redecl_out_of_scope;
5903 S.Diag(Loc, Diag) << EntityKind << Specialized
5904 << cast<NamedDecl>(SpecializedContext);
5906 llvm_unreachable("unexpected namespace context for specialization");
5908 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
5909 } else if ((!PrevDecl ||
5910 getTemplateSpecializationKind(PrevDecl) == TSK_Undeclared ||
5911 getTemplateSpecializationKind(PrevDecl) ==
5912 TSK_ImplicitInstantiation)) {
5913 // C++ [temp.exp.spec]p2:
5914 // An explicit specialization shall be declared in the namespace of which
5915 // the template is a member, or, for member templates, in the namespace
5916 // of which the enclosing class or enclosing class template is a member.
5917 // An explicit specialization of a member function, member class or
5918 // static data member of a class template shall be declared in the
5919 // namespace of which the class template is a member.
5921 // C++11 [temp.expl.spec]p2:
5922 // An explicit specialization shall be declared in a namespace enclosing
5923 // the specialized template.
5924 // C++11 [temp.explicit]p3:
5925 // An explicit instantiation shall appear in an enclosing namespace of its
5927 if (!DC->InEnclosingNamespaceSetOf(SpecializedContext)) {
5928 bool IsCPlusPlus11Extension = DC->Encloses(SpecializedContext);
5929 if (isa<TranslationUnitDecl>(SpecializedContext)) {
5930 assert(!IsCPlusPlus11Extension &&
5931 "DC encloses TU but isn't in enclosing namespace set");
5932 S.Diag(Loc, diag::err_template_spec_decl_out_of_scope_global)
5933 << EntityKind << Specialized;
5934 } else if (isa<NamespaceDecl>(SpecializedContext)) {
5936 if (!IsCPlusPlus11Extension)
5937 Diag = diag::err_template_spec_decl_out_of_scope;
5938 else if (!S.getLangOpts().CPlusPlus11)
5939 Diag = diag::ext_template_spec_decl_out_of_scope;
5941 Diag = diag::warn_cxx98_compat_template_spec_decl_out_of_scope;
5943 << EntityKind << Specialized << cast<NamedDecl>(SpecializedContext);
5946 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
5953 static SourceRange findTemplateParameter(unsigned Depth, Expr *E) {
5954 if (!E->isInstantiationDependent())
5955 return SourceLocation();
5956 DependencyChecker Checker(Depth);
5957 Checker.TraverseStmt(E);
5958 if (Checker.Match && Checker.MatchLoc.isInvalid())
5959 return E->getSourceRange();
5960 return Checker.MatchLoc;
5963 static SourceRange findTemplateParameter(unsigned Depth, TypeLoc TL) {
5964 if (!TL.getType()->isDependentType())
5965 return SourceLocation();
5966 DependencyChecker Checker(Depth);
5967 Checker.TraverseTypeLoc(TL);
5968 if (Checker.Match && Checker.MatchLoc.isInvalid())
5969 return TL.getSourceRange();
5970 return Checker.MatchLoc;
5973 /// \brief Subroutine of Sema::CheckTemplatePartialSpecializationArgs
5974 /// that checks non-type template partial specialization arguments.
5975 static bool CheckNonTypeTemplatePartialSpecializationArgs(
5976 Sema &S, SourceLocation TemplateNameLoc, NonTypeTemplateParmDecl *Param,
5977 const TemplateArgument *Args, unsigned NumArgs, bool IsDefaultArgument) {
5978 for (unsigned I = 0; I != NumArgs; ++I) {
5979 if (Args[I].getKind() == TemplateArgument::Pack) {
5980 if (CheckNonTypeTemplatePartialSpecializationArgs(
5981 S, TemplateNameLoc, Param, Args[I].pack_begin(),
5982 Args[I].pack_size(), IsDefaultArgument))
5988 if (Args[I].getKind() != TemplateArgument::Expression)
5991 Expr *ArgExpr = Args[I].getAsExpr();
5993 // We can have a pack expansion of any of the bullets below.
5994 if (PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(ArgExpr))
5995 ArgExpr = Expansion->getPattern();
5997 // Strip off any implicit casts we added as part of type checking.
5998 while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
5999 ArgExpr = ICE->getSubExpr();
6001 // C++ [temp.class.spec]p8:
6002 // A non-type argument is non-specialized if it is the name of a
6003 // non-type parameter. All other non-type arguments are
6006 // Below, we check the two conditions that only apply to
6007 // specialized non-type arguments, so skip any non-specialized
6009 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ArgExpr))
6010 if (isa<NonTypeTemplateParmDecl>(DRE->getDecl()))
6013 // C++ [temp.class.spec]p9:
6014 // Within the argument list of a class template partial
6015 // specialization, the following restrictions apply:
6016 // -- A partially specialized non-type argument expression
6017 // shall not involve a template parameter of the partial
6018 // specialization except when the argument expression is a
6019 // simple identifier.
6020 SourceRange ParamUseRange =
6021 findTemplateParameter(Param->getDepth(), ArgExpr);
6022 if (ParamUseRange.isValid()) {
6023 if (IsDefaultArgument) {
6024 S.Diag(TemplateNameLoc,
6025 diag::err_dependent_non_type_arg_in_partial_spec);
6026 S.Diag(ParamUseRange.getBegin(),
6027 diag::note_dependent_non_type_default_arg_in_partial_spec)
6030 S.Diag(ParamUseRange.getBegin(),
6031 diag::err_dependent_non_type_arg_in_partial_spec)
6037 // -- The type of a template parameter corresponding to a
6038 // specialized non-type argument shall not be dependent on a
6039 // parameter of the specialization.
6041 // FIXME: We need to delay this check until instantiation in some cases:
6043 // template<template<typename> class X> struct A {
6044 // template<typename T, X<T> N> struct B;
6045 // template<typename T> struct B<T, 0>;
6047 // template<typename> using X = int;
6048 // A<X>::B<int, 0> b;
6049 ParamUseRange = findTemplateParameter(
6050 Param->getDepth(), Param->getTypeSourceInfo()->getTypeLoc());
6051 if (ParamUseRange.isValid()) {
6052 S.Diag(IsDefaultArgument ? TemplateNameLoc : ArgExpr->getLocStart(),
6053 diag::err_dependent_typed_non_type_arg_in_partial_spec)
6054 << Param->getType() << ParamUseRange;
6055 S.Diag(Param->getLocation(), diag::note_template_param_here)
6056 << (IsDefaultArgument ? ParamUseRange : SourceRange());
6064 /// \brief Check the non-type template arguments of a class template
6065 /// partial specialization according to C++ [temp.class.spec]p9.
6067 /// \param TemplateNameLoc the location of the template name.
6068 /// \param TemplateParams the template parameters of the primary class
6070 /// \param NumExplicit the number of explicitly-specified template arguments.
6071 /// \param TemplateArgs the template arguments of the class template
6072 /// partial specialization.
6074 /// \returns \c true if there was an error, \c false otherwise.
6075 static bool CheckTemplatePartialSpecializationArgs(
6076 Sema &S, SourceLocation TemplateNameLoc,
6077 TemplateParameterList *TemplateParams, unsigned NumExplicit,
6078 SmallVectorImpl<TemplateArgument> &TemplateArgs) {
6079 const TemplateArgument *ArgList = TemplateArgs.data();
6081 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
6082 NonTypeTemplateParmDecl *Param
6083 = dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(I));
6087 if (CheckNonTypeTemplatePartialSpecializationArgs(
6088 S, TemplateNameLoc, Param, &ArgList[I], 1, I >= NumExplicit))
6096 Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec,
6098 SourceLocation KWLoc,
6099 SourceLocation ModulePrivateLoc,
6100 TemplateIdAnnotation &TemplateId,
6101 AttributeList *Attr,
6102 MultiTemplateParamsArg
6103 TemplateParameterLists,
6104 SkipBodyInfo *SkipBody) {
6105 assert(TUK != TUK_Reference && "References are not specializations");
6107 CXXScopeSpec &SS = TemplateId.SS;
6109 // NOTE: KWLoc is the location of the tag keyword. This will instead
6110 // store the location of the outermost template keyword in the declaration.
6111 SourceLocation TemplateKWLoc = TemplateParameterLists.size() > 0
6112 ? TemplateParameterLists[0]->getTemplateLoc() : KWLoc;
6113 SourceLocation TemplateNameLoc = TemplateId.TemplateNameLoc;
6114 SourceLocation LAngleLoc = TemplateId.LAngleLoc;
6115 SourceLocation RAngleLoc = TemplateId.RAngleLoc;
6117 // Find the class template we're specializing
6118 TemplateName Name = TemplateId.Template.get();
6119 ClassTemplateDecl *ClassTemplate
6120 = dyn_cast_or_null<ClassTemplateDecl>(Name.getAsTemplateDecl());
6122 if (!ClassTemplate) {
6123 Diag(TemplateNameLoc, diag::err_not_class_template_specialization)
6124 << (Name.getAsTemplateDecl() &&
6125 isa<TemplateTemplateParmDecl>(Name.getAsTemplateDecl()));
6129 bool isExplicitSpecialization = false;
6130 bool isPartialSpecialization = false;
6132 // Check the validity of the template headers that introduce this
6134 // FIXME: We probably shouldn't complain about these headers for
6135 // friend declarations.
6136 bool Invalid = false;
6137 TemplateParameterList *TemplateParams =
6138 MatchTemplateParametersToScopeSpecifier(
6139 KWLoc, TemplateNameLoc, SS, &TemplateId,
6140 TemplateParameterLists, TUK == TUK_Friend, isExplicitSpecialization,
6145 if (TemplateParams && TemplateParams->size() > 0) {
6146 isPartialSpecialization = true;
6148 if (TUK == TUK_Friend) {
6149 Diag(KWLoc, diag::err_partial_specialization_friend)
6150 << SourceRange(LAngleLoc, RAngleLoc);
6154 // C++ [temp.class.spec]p10:
6155 // The template parameter list of a specialization shall not
6156 // contain default template argument values.
6157 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
6158 Decl *Param = TemplateParams->getParam(I);
6159 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) {
6160 if (TTP->hasDefaultArgument()) {
6161 Diag(TTP->getDefaultArgumentLoc(),
6162 diag::err_default_arg_in_partial_spec);
6163 TTP->removeDefaultArgument();
6165 } else if (NonTypeTemplateParmDecl *NTTP
6166 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
6167 if (Expr *DefArg = NTTP->getDefaultArgument()) {
6168 Diag(NTTP->getDefaultArgumentLoc(),
6169 diag::err_default_arg_in_partial_spec)
6170 << DefArg->getSourceRange();
6171 NTTP->removeDefaultArgument();
6174 TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(Param);
6175 if (TTP->hasDefaultArgument()) {
6176 Diag(TTP->getDefaultArgument().getLocation(),
6177 diag::err_default_arg_in_partial_spec)
6178 << TTP->getDefaultArgument().getSourceRange();
6179 TTP->removeDefaultArgument();
6183 } else if (TemplateParams) {
6184 if (TUK == TUK_Friend)
6185 Diag(KWLoc, diag::err_template_spec_friend)
6186 << FixItHint::CreateRemoval(
6187 SourceRange(TemplateParams->getTemplateLoc(),
6188 TemplateParams->getRAngleLoc()))
6189 << SourceRange(LAngleLoc, RAngleLoc);
6191 isExplicitSpecialization = true;
6193 assert(TUK == TUK_Friend && "should have a 'template<>' for this decl");
6196 // Check that the specialization uses the same tag kind as the
6197 // original template.
6198 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
6199 assert(Kind != TTK_Enum && "Invalid enum tag in class template spec!");
6200 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
6201 Kind, TUK == TUK_Definition, KWLoc,
6202 ClassTemplate->getIdentifier())) {
6203 Diag(KWLoc, diag::err_use_with_wrong_tag)
6205 << FixItHint::CreateReplacement(KWLoc,
6206 ClassTemplate->getTemplatedDecl()->getKindName());
6207 Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
6208 diag::note_previous_use);
6209 Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
6212 // Translate the parser's template argument list in our AST format.
6213 TemplateArgumentListInfo TemplateArgs =
6214 makeTemplateArgumentListInfo(*this, TemplateId);
6216 // Check for unexpanded parameter packs in any of the template arguments.
6217 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
6218 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
6219 UPPC_PartialSpecialization))
6222 // Check that the template argument list is well-formed for this
6224 SmallVector<TemplateArgument, 4> Converted;
6225 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
6226 TemplateArgs, false, Converted))
6229 // Find the class template (partial) specialization declaration that
6230 // corresponds to these arguments.
6231 if (isPartialSpecialization) {
6232 if (CheckTemplatePartialSpecializationArgs(
6233 *this, TemplateNameLoc, ClassTemplate->getTemplateParameters(),
6234 TemplateArgs.size(), Converted))
6237 bool InstantiationDependent;
6238 if (!Name.isDependent() &&
6239 !TemplateSpecializationType::anyDependentTemplateArguments(
6240 TemplateArgs.getArgumentArray(),
6241 TemplateArgs.size(),
6242 InstantiationDependent)) {
6243 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
6244 << ClassTemplate->getDeclName();
6245 isPartialSpecialization = false;
6249 void *InsertPos = nullptr;
6250 ClassTemplateSpecializationDecl *PrevDecl = nullptr;
6252 if (isPartialSpecialization)
6253 // FIXME: Template parameter list matters, too
6254 PrevDecl = ClassTemplate->findPartialSpecialization(Converted, InsertPos);
6256 PrevDecl = ClassTemplate->findSpecialization(Converted, InsertPos);
6258 ClassTemplateSpecializationDecl *Specialization = nullptr;
6260 // Check whether we can declare a class template specialization in
6261 // the current scope.
6262 if (TUK != TUK_Friend &&
6263 CheckTemplateSpecializationScope(*this, ClassTemplate, PrevDecl,
6265 isPartialSpecialization))
6268 // The canonical type
6270 if (isPartialSpecialization) {
6271 // Build the canonical type that describes the converted template
6272 // arguments of the class template partial specialization.
6273 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
6274 CanonType = Context.getTemplateSpecializationType(CanonTemplate,
6278 if (Context.hasSameType(CanonType,
6279 ClassTemplate->getInjectedClassNameSpecialization())) {
6280 // C++ [temp.class.spec]p9b3:
6282 // -- The argument list of the specialization shall not be identical
6283 // to the implicit argument list of the primary template.
6284 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
6285 << /*class template*/0 << (TUK == TUK_Definition)
6286 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
6287 return CheckClassTemplate(S, TagSpec, TUK, KWLoc, SS,
6288 ClassTemplate->getIdentifier(),
6292 AS_none, /*ModulePrivateLoc=*/SourceLocation(),
6293 /*FriendLoc*/SourceLocation(),
6294 TemplateParameterLists.size() - 1,
6295 TemplateParameterLists.data());
6298 // Create a new class template partial specialization declaration node.
6299 ClassTemplatePartialSpecializationDecl *PrevPartial
6300 = cast_or_null<ClassTemplatePartialSpecializationDecl>(PrevDecl);
6301 ClassTemplatePartialSpecializationDecl *Partial
6302 = ClassTemplatePartialSpecializationDecl::Create(Context, Kind,
6303 ClassTemplate->getDeclContext(),
6304 KWLoc, TemplateNameLoc,
6312 SetNestedNameSpecifier(Partial, SS);
6313 if (TemplateParameterLists.size() > 1 && SS.isSet()) {
6314 Partial->setTemplateParameterListsInfo(Context,
6315 TemplateParameterLists.size() - 1,
6316 TemplateParameterLists.data());
6320 ClassTemplate->AddPartialSpecialization(Partial, InsertPos);
6321 Specialization = Partial;
6323 // If we are providing an explicit specialization of a member class
6324 // template specialization, make a note of that.
6325 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
6326 PrevPartial->setMemberSpecialization();
6328 // Check that all of the template parameters of the class template
6329 // partial specialization are deducible from the template
6330 // arguments. If not, this class template partial specialization
6331 // will never be used.
6332 llvm::SmallBitVector DeducibleParams(TemplateParams->size());
6333 MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
6334 TemplateParams->getDepth(),
6337 if (!DeducibleParams.all()) {
6338 unsigned NumNonDeducible = DeducibleParams.size()-DeducibleParams.count();
6339 Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible)
6340 << /*class template*/0 << (NumNonDeducible > 1)
6341 << SourceRange(TemplateNameLoc, RAngleLoc);
6342 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) {
6343 if (!DeducibleParams[I]) {
6344 NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I));
6345 if (Param->getDeclName())
6346 Diag(Param->getLocation(),
6347 diag::note_partial_spec_unused_parameter)
6348 << Param->getDeclName();
6350 Diag(Param->getLocation(),
6351 diag::note_partial_spec_unused_parameter)
6357 // Create a new class template specialization declaration node for
6358 // this explicit specialization or friend declaration.
6360 = ClassTemplateSpecializationDecl::Create(Context, Kind,
6361 ClassTemplate->getDeclContext(),
6362 KWLoc, TemplateNameLoc,
6367 SetNestedNameSpecifier(Specialization, SS);
6368 if (TemplateParameterLists.size() > 0) {
6369 Specialization->setTemplateParameterListsInfo(Context,
6370 TemplateParameterLists.size(),
6371 TemplateParameterLists.data());
6375 ClassTemplate->AddSpecialization(Specialization, InsertPos);
6377 CanonType = Context.getTypeDeclType(Specialization);
6380 // C++ [temp.expl.spec]p6:
6381 // If a template, a member template or the member of a class template is
6382 // explicitly specialized then that specialization shall be declared
6383 // before the first use of that specialization that would cause an implicit
6384 // instantiation to take place, in every translation unit in which such a
6385 // use occurs; no diagnostic is required.
6386 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
6388 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6389 // Is there any previous explicit specialization declaration?
6390 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
6397 SourceRange Range(TemplateNameLoc, RAngleLoc);
6398 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
6399 << Context.getTypeDeclType(Specialization) << Range;
6401 Diag(PrevDecl->getPointOfInstantiation(),
6402 diag::note_instantiation_required_here)
6403 << (PrevDecl->getTemplateSpecializationKind()
6404 != TSK_ImplicitInstantiation);
6409 // If this is not a friend, note that this is an explicit specialization.
6410 if (TUK != TUK_Friend)
6411 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
6413 // Check that this isn't a redefinition of this specialization.
6414 if (TUK == TUK_Definition) {
6415 RecordDecl *Def = Specialization->getDefinition();
6416 NamedDecl *Hidden = nullptr;
6417 if (Def && SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
6418 SkipBody->ShouldSkip = true;
6419 makeMergedDefinitionVisible(Hidden, KWLoc);
6420 // From here on out, treat this as just a redeclaration.
6421 TUK = TUK_Declaration;
6423 SourceRange Range(TemplateNameLoc, RAngleLoc);
6424 Diag(TemplateNameLoc, diag::err_redefinition)
6425 << Context.getTypeDeclType(Specialization) << Range;
6426 Diag(Def->getLocation(), diag::note_previous_definition);
6427 Specialization->setInvalidDecl();
6433 ProcessDeclAttributeList(S, Specialization, Attr);
6435 // Add alignment attributes if necessary; these attributes are checked when
6436 // the ASTContext lays out the structure.
6437 if (TUK == TUK_Definition) {
6438 AddAlignmentAttributesForRecord(Specialization);
6439 AddMsStructLayoutForRecord(Specialization);
6442 if (ModulePrivateLoc.isValid())
6443 Diag(Specialization->getLocation(), diag::err_module_private_specialization)
6444 << (isPartialSpecialization? 1 : 0)
6445 << FixItHint::CreateRemoval(ModulePrivateLoc);
6447 // Build the fully-sugared type for this class template
6448 // specialization as the user wrote in the specialization
6449 // itself. This means that we'll pretty-print the type retrieved
6450 // from the specialization's declaration the way that the user
6451 // actually wrote the specialization, rather than formatting the
6452 // name based on the "canonical" representation used to store the
6453 // template arguments in the specialization.
6454 TypeSourceInfo *WrittenTy
6455 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
6456 TemplateArgs, CanonType);
6457 if (TUK != TUK_Friend) {
6458 Specialization->setTypeAsWritten(WrittenTy);
6459 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
6462 // C++ [temp.expl.spec]p9:
6463 // A template explicit specialization is in the scope of the
6464 // namespace in which the template was defined.
6466 // We actually implement this paragraph where we set the semantic
6467 // context (in the creation of the ClassTemplateSpecializationDecl),
6468 // but we also maintain the lexical context where the actual
6469 // definition occurs.
6470 Specialization->setLexicalDeclContext(CurContext);
6472 // We may be starting the definition of this specialization.
6473 if (TUK == TUK_Definition)
6474 Specialization->startDefinition();
6476 if (TUK == TUK_Friend) {
6477 FriendDecl *Friend = FriendDecl::Create(Context, CurContext,
6481 Friend->setAccess(AS_public);
6482 CurContext->addDecl(Friend);
6484 // Add the specialization into its lexical context, so that it can
6485 // be seen when iterating through the list of declarations in that
6486 // context. However, specializations are not found by name lookup.
6487 CurContext->addDecl(Specialization);
6489 return Specialization;
6492 Decl *Sema::ActOnTemplateDeclarator(Scope *S,
6493 MultiTemplateParamsArg TemplateParameterLists,
6495 Decl *NewDecl = HandleDeclarator(S, D, TemplateParameterLists);
6496 ActOnDocumentableDecl(NewDecl);
6500 Decl *Sema::ActOnStartOfFunctionTemplateDef(Scope *FnBodyScope,
6501 MultiTemplateParamsArg TemplateParameterLists,
6503 assert(getCurFunctionDecl() == nullptr && "Function parsing confused");
6504 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
6506 if (FTI.hasPrototype) {
6507 // FIXME: Diagnose arguments without names in C.
6510 Scope *ParentScope = FnBodyScope->getParent();
6512 D.setFunctionDefinitionKind(FDK_Definition);
6513 Decl *DP = HandleDeclarator(ParentScope, D,
6514 TemplateParameterLists);
6515 return ActOnStartOfFunctionDef(FnBodyScope, DP);
6518 /// \brief Strips various properties off an implicit instantiation
6519 /// that has just been explicitly specialized.
6520 static void StripImplicitInstantiation(NamedDecl *D) {
6521 D->dropAttr<DLLImportAttr>();
6522 D->dropAttr<DLLExportAttr>();
6524 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
6525 FD->setInlineSpecified(false);
6528 /// \brief Compute the diagnostic location for an explicit instantiation
6529 // declaration or definition.
6530 static SourceLocation DiagLocForExplicitInstantiation(
6531 NamedDecl* D, SourceLocation PointOfInstantiation) {
6532 // Explicit instantiations following a specialization have no effect and
6533 // hence no PointOfInstantiation. In that case, walk decl backwards
6534 // until a valid name loc is found.
6535 SourceLocation PrevDiagLoc = PointOfInstantiation;
6536 for (Decl *Prev = D; Prev && !PrevDiagLoc.isValid();
6537 Prev = Prev->getPreviousDecl()) {
6538 PrevDiagLoc = Prev->getLocation();
6540 assert(PrevDiagLoc.isValid() &&
6541 "Explicit instantiation without point of instantiation?");
6545 /// \brief Diagnose cases where we have an explicit template specialization
6546 /// before/after an explicit template instantiation, producing diagnostics
6547 /// for those cases where they are required and determining whether the
6548 /// new specialization/instantiation will have any effect.
6550 /// \param NewLoc the location of the new explicit specialization or
6553 /// \param NewTSK the kind of the new explicit specialization or instantiation.
6555 /// \param PrevDecl the previous declaration of the entity.
6557 /// \param PrevTSK the kind of the old explicit specialization or instantiatin.
6559 /// \param PrevPointOfInstantiation if valid, indicates where the previus
6560 /// declaration was instantiated (either implicitly or explicitly).
6562 /// \param HasNoEffect will be set to true to indicate that the new
6563 /// specialization or instantiation has no effect and should be ignored.
6565 /// \returns true if there was an error that should prevent the introduction of
6566 /// the new declaration into the AST, false otherwise.
6568 Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc,
6569 TemplateSpecializationKind NewTSK,
6570 NamedDecl *PrevDecl,
6571 TemplateSpecializationKind PrevTSK,
6572 SourceLocation PrevPointOfInstantiation,
6573 bool &HasNoEffect) {
6574 HasNoEffect = false;
6577 case TSK_Undeclared:
6578 case TSK_ImplicitInstantiation:
6580 (PrevTSK == TSK_Undeclared || PrevTSK == TSK_ImplicitInstantiation) &&
6581 "previous declaration must be implicit!");
6584 case TSK_ExplicitSpecialization:
6586 case TSK_Undeclared:
6587 case TSK_ExplicitSpecialization:
6588 // Okay, we're just specializing something that is either already
6589 // explicitly specialized or has merely been mentioned without any
6593 case TSK_ImplicitInstantiation:
6594 if (PrevPointOfInstantiation.isInvalid()) {
6595 // The declaration itself has not actually been instantiated, so it is
6596 // still okay to specialize it.
6597 StripImplicitInstantiation(PrevDecl);
6602 case TSK_ExplicitInstantiationDeclaration:
6603 case TSK_ExplicitInstantiationDefinition:
6604 assert((PrevTSK == TSK_ImplicitInstantiation ||
6605 PrevPointOfInstantiation.isValid()) &&
6606 "Explicit instantiation without point of instantiation?");
6608 // C++ [temp.expl.spec]p6:
6609 // If a template, a member template or the member of a class template
6610 // is explicitly specialized then that specialization shall be declared
6611 // before the first use of that specialization that would cause an
6612 // implicit instantiation to take place, in every translation unit in
6613 // which such a use occurs; no diagnostic is required.
6614 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6615 // Is there any previous explicit specialization declaration?
6616 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization)
6620 Diag(NewLoc, diag::err_specialization_after_instantiation)
6622 Diag(PrevPointOfInstantiation, diag::note_instantiation_required_here)
6623 << (PrevTSK != TSK_ImplicitInstantiation);
6628 case TSK_ExplicitInstantiationDeclaration:
6630 case TSK_ExplicitInstantiationDeclaration:
6631 // This explicit instantiation declaration is redundant (that's okay).
6635 case TSK_Undeclared:
6636 case TSK_ImplicitInstantiation:
6637 // We're explicitly instantiating something that may have already been
6638 // implicitly instantiated; that's fine.
6641 case TSK_ExplicitSpecialization:
6642 // C++0x [temp.explicit]p4:
6643 // For a given set of template parameters, if an explicit instantiation
6644 // of a template appears after a declaration of an explicit
6645 // specialization for that template, the explicit instantiation has no
6650 case TSK_ExplicitInstantiationDefinition:
6651 // C++0x [temp.explicit]p10:
6652 // If an entity is the subject of both an explicit instantiation
6653 // declaration and an explicit instantiation definition in the same
6654 // translation unit, the definition shall follow the declaration.
6656 diag::err_explicit_instantiation_declaration_after_definition);
6658 // Explicit instantiations following a specialization have no effect and
6659 // hence no PrevPointOfInstantiation. In that case, walk decl backwards
6660 // until a valid name loc is found.
6661 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
6662 diag::note_explicit_instantiation_definition_here);
6667 case TSK_ExplicitInstantiationDefinition:
6669 case TSK_Undeclared:
6670 case TSK_ImplicitInstantiation:
6671 // We're explicitly instantiating something that may have already been
6672 // implicitly instantiated; that's fine.
6675 case TSK_ExplicitSpecialization:
6676 // C++ DR 259, C++0x [temp.explicit]p4:
6677 // For a given set of template parameters, if an explicit
6678 // instantiation of a template appears after a declaration of
6679 // an explicit specialization for that template, the explicit
6680 // instantiation has no effect.
6682 // In C++98/03 mode, we only give an extension warning here, because it
6683 // is not harmful to try to explicitly instantiate something that
6684 // has been explicitly specialized.
6685 Diag(NewLoc, getLangOpts().CPlusPlus11 ?
6686 diag::warn_cxx98_compat_explicit_instantiation_after_specialization :
6687 diag::ext_explicit_instantiation_after_specialization)
6689 Diag(PrevDecl->getLocation(),
6690 diag::note_previous_template_specialization);
6694 case TSK_ExplicitInstantiationDeclaration:
6695 // We're explicity instantiating a definition for something for which we
6696 // were previously asked to suppress instantiations. That's fine.
6698 // C++0x [temp.explicit]p4:
6699 // For a given set of template parameters, if an explicit instantiation
6700 // of a template appears after a declaration of an explicit
6701 // specialization for that template, the explicit instantiation has no
6703 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6704 // Is there any previous explicit specialization declaration?
6705 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
6713 case TSK_ExplicitInstantiationDefinition:
6714 // C++0x [temp.spec]p5:
6715 // For a given template and a given set of template-arguments,
6716 // - an explicit instantiation definition shall appear at most once
6719 // MSVCCompat: MSVC silently ignores duplicate explicit instantiations.
6720 Diag(NewLoc, (getLangOpts().MSVCCompat)
6721 ? diag::ext_explicit_instantiation_duplicate
6722 : diag::err_explicit_instantiation_duplicate)
6724 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
6725 diag::note_previous_explicit_instantiation);
6731 llvm_unreachable("Missing specialization/instantiation case?");
6734 /// \brief Perform semantic analysis for the given dependent function
6735 /// template specialization.
6737 /// The only possible way to get a dependent function template specialization
6738 /// is with a friend declaration, like so:
6741 /// template \<class T> void foo(T);
6742 /// template \<class T> class A {
6743 /// friend void foo<>(T);
6747 /// There really isn't any useful analysis we can do here, so we
6748 /// just store the information.
6750 Sema::CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD,
6751 const TemplateArgumentListInfo &ExplicitTemplateArgs,
6752 LookupResult &Previous) {
6753 // Remove anything from Previous that isn't a function template in
6754 // the correct context.
6755 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
6756 LookupResult::Filter F = Previous.makeFilter();
6757 while (F.hasNext()) {
6758 NamedDecl *D = F.next()->getUnderlyingDecl();
6759 if (!isa<FunctionTemplateDecl>(D) ||
6760 !FDLookupContext->InEnclosingNamespaceSetOf(
6761 D->getDeclContext()->getRedeclContext()))
6766 // Should this be diagnosed here?
6767 if (Previous.empty()) return true;
6769 FD->setDependentTemplateSpecialization(Context, Previous.asUnresolvedSet(),
6770 ExplicitTemplateArgs);
6774 /// \brief Perform semantic analysis for the given function template
6777 /// This routine performs all of the semantic analysis required for an
6778 /// explicit function template specialization. On successful completion,
6779 /// the function declaration \p FD will become a function template
6782 /// \param FD the function declaration, which will be updated to become a
6783 /// function template specialization.
6785 /// \param ExplicitTemplateArgs the explicitly-provided template arguments,
6786 /// if any. Note that this may be valid info even when 0 arguments are
6787 /// explicitly provided as in, e.g., \c void sort<>(char*, char*);
6788 /// as it anyway contains info on the angle brackets locations.
6790 /// \param Previous the set of declarations that may be specialized by
6791 /// this function specialization.
6792 bool Sema::CheckFunctionTemplateSpecialization(
6793 FunctionDecl *FD, TemplateArgumentListInfo *ExplicitTemplateArgs,
6794 LookupResult &Previous) {
6795 // The set of function template specializations that could match this
6796 // explicit function template specialization.
6797 UnresolvedSet<8> Candidates;
6798 TemplateSpecCandidateSet FailedCandidates(FD->getLocation());
6800 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
6801 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
6803 NamedDecl *Ovl = (*I)->getUnderlyingDecl();
6804 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Ovl)) {
6805 // Only consider templates found within the same semantic lookup scope as
6807 if (!FDLookupContext->InEnclosingNamespaceSetOf(
6808 Ovl->getDeclContext()->getRedeclContext()))
6811 // When matching a constexpr member function template specialization
6812 // against the primary template, we don't yet know whether the
6813 // specialization has an implicit 'const' (because we don't know whether
6814 // it will be a static member function until we know which template it
6815 // specializes), so adjust it now assuming it specializes this template.
6816 QualType FT = FD->getType();
6817 if (FD->isConstexpr()) {
6818 CXXMethodDecl *OldMD =
6819 dyn_cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl());
6820 if (OldMD && OldMD->isConst()) {
6821 const FunctionProtoType *FPT = FT->castAs<FunctionProtoType>();
6822 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
6823 EPI.TypeQuals |= Qualifiers::Const;
6824 FT = Context.getFunctionType(FPT->getReturnType(),
6825 FPT->getParamTypes(), EPI);
6829 // C++ [temp.expl.spec]p11:
6830 // A trailing template-argument can be left unspecified in the
6831 // template-id naming an explicit function template specialization
6832 // provided it can be deduced from the function argument type.
6833 // Perform template argument deduction to determine whether we may be
6834 // specializing this template.
6835 // FIXME: It is somewhat wasteful to build
6836 TemplateDeductionInfo Info(FailedCandidates.getLocation());
6837 FunctionDecl *Specialization = nullptr;
6838 if (TemplateDeductionResult TDK = DeduceTemplateArguments(
6839 cast<FunctionTemplateDecl>(FunTmpl->getFirstDecl()),
6840 ExplicitTemplateArgs, FT, Specialization, Info)) {
6841 // Template argument deduction failed; record why it failed, so
6842 // that we can provide nifty diagnostics.
6843 FailedCandidates.addCandidate()
6844 .set(FunTmpl->getTemplatedDecl(),
6845 MakeDeductionFailureInfo(Context, TDK, Info));
6850 // Record this candidate.
6851 Candidates.addDecl(Specialization, I.getAccess());
6855 // Find the most specialized function template.
6856 UnresolvedSetIterator Result = getMostSpecialized(
6857 Candidates.begin(), Candidates.end(), FailedCandidates,
6859 PDiag(diag::err_function_template_spec_no_match) << FD->getDeclName(),
6860 PDiag(diag::err_function_template_spec_ambiguous)
6861 << FD->getDeclName() << (ExplicitTemplateArgs != nullptr),
6862 PDiag(diag::note_function_template_spec_matched));
6864 if (Result == Candidates.end())
6867 // Ignore access information; it doesn't figure into redeclaration checking.
6868 FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
6870 FunctionTemplateSpecializationInfo *SpecInfo
6871 = Specialization->getTemplateSpecializationInfo();
6872 assert(SpecInfo && "Function template specialization info missing?");
6874 // Note: do not overwrite location info if previous template
6875 // specialization kind was explicit.
6876 TemplateSpecializationKind TSK = SpecInfo->getTemplateSpecializationKind();
6877 if (TSK == TSK_Undeclared || TSK == TSK_ImplicitInstantiation) {
6878 Specialization->setLocation(FD->getLocation());
6879 // C++11 [dcl.constexpr]p1: An explicit specialization of a constexpr
6880 // function can differ from the template declaration with respect to
6881 // the constexpr specifier.
6882 Specialization->setConstexpr(FD->isConstexpr());
6885 // FIXME: Check if the prior specialization has a point of instantiation.
6886 // If so, we have run afoul of .
6888 // If this is a friend declaration, then we're not really declaring
6889 // an explicit specialization.
6890 bool isFriend = (FD->getFriendObjectKind() != Decl::FOK_None);
6892 // Check the scope of this explicit specialization.
6894 CheckTemplateSpecializationScope(*this,
6895 Specialization->getPrimaryTemplate(),
6896 Specialization, FD->getLocation(),
6900 // C++ [temp.expl.spec]p6:
6901 // If a template, a member template or the member of a class template is
6902 // explicitly specialized then that specialization shall be declared
6903 // before the first use of that specialization that would cause an implicit
6904 // instantiation to take place, in every translation unit in which such a
6905 // use occurs; no diagnostic is required.
6906 bool HasNoEffect = false;
6908 CheckSpecializationInstantiationRedecl(FD->getLocation(),
6909 TSK_ExplicitSpecialization,
6911 SpecInfo->getTemplateSpecializationKind(),
6912 SpecInfo->getPointOfInstantiation(),
6916 // Mark the prior declaration as an explicit specialization, so that later
6917 // clients know that this is an explicit specialization.
6919 SpecInfo->setTemplateSpecializationKind(TSK_ExplicitSpecialization);
6920 MarkUnusedFileScopedDecl(Specialization);
6923 // Turn the given function declaration into a function template
6924 // specialization, with the template arguments from the previous
6926 // Take copies of (semantic and syntactic) template argument lists.
6927 const TemplateArgumentList* TemplArgs = new (Context)
6928 TemplateArgumentList(Specialization->getTemplateSpecializationArgs());
6929 FD->setFunctionTemplateSpecialization(Specialization->getPrimaryTemplate(),
6930 TemplArgs, /*InsertPos=*/nullptr,
6931 SpecInfo->getTemplateSpecializationKind(),
6932 ExplicitTemplateArgs);
6934 // The "previous declaration" for this function template specialization is
6935 // the prior function template specialization.
6937 Previous.addDecl(Specialization);
6941 /// \brief Perform semantic analysis for the given non-template member
6944 /// This routine performs all of the semantic analysis required for an
6945 /// explicit member function specialization. On successful completion,
6946 /// the function declaration \p FD will become a member function
6949 /// \param Member the member declaration, which will be updated to become a
6952 /// \param Previous the set of declarations, one of which may be specialized
6953 /// by this function specialization; the set will be modified to contain the
6954 /// redeclared member.
6956 Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
6957 assert(!isa<TemplateDecl>(Member) && "Only for non-template members");
6959 // Try to find the member we are instantiating.
6960 NamedDecl *Instantiation = nullptr;
6961 NamedDecl *InstantiatedFrom = nullptr;
6962 MemberSpecializationInfo *MSInfo = nullptr;
6964 if (Previous.empty()) {
6965 // Nowhere to look anyway.
6966 } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Member)) {
6967 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
6969 NamedDecl *D = (*I)->getUnderlyingDecl();
6970 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
6971 QualType Adjusted = Function->getType();
6972 if (!hasExplicitCallingConv(Adjusted))
6973 Adjusted = adjustCCAndNoReturn(Adjusted, Method->getType());
6974 if (Context.hasSameType(Adjusted, Method->getType())) {
6975 Instantiation = Method;
6976 InstantiatedFrom = Method->getInstantiatedFromMemberFunction();
6977 MSInfo = Method->getMemberSpecializationInfo();
6982 } else if (isa<VarDecl>(Member)) {
6984 if (Previous.isSingleResult() &&
6985 (PrevVar = dyn_cast<VarDecl>(Previous.getFoundDecl())))
6986 if (PrevVar->isStaticDataMember()) {
6987 Instantiation = PrevVar;
6988 InstantiatedFrom = PrevVar->getInstantiatedFromStaticDataMember();
6989 MSInfo = PrevVar->getMemberSpecializationInfo();
6991 } else if (isa<RecordDecl>(Member)) {
6992 CXXRecordDecl *PrevRecord;
6993 if (Previous.isSingleResult() &&
6994 (PrevRecord = dyn_cast<CXXRecordDecl>(Previous.getFoundDecl()))) {
6995 Instantiation = PrevRecord;
6996 InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass();
6997 MSInfo = PrevRecord->getMemberSpecializationInfo();
6999 } else if (isa<EnumDecl>(Member)) {
7001 if (Previous.isSingleResult() &&
7002 (PrevEnum = dyn_cast<EnumDecl>(Previous.getFoundDecl()))) {
7003 Instantiation = PrevEnum;
7004 InstantiatedFrom = PrevEnum->getInstantiatedFromMemberEnum();
7005 MSInfo = PrevEnum->getMemberSpecializationInfo();
7009 if (!Instantiation) {
7010 // There is no previous declaration that matches. Since member
7011 // specializations are always out-of-line, the caller will complain about
7012 // this mismatch later.
7016 // If this is a friend, just bail out here before we start turning
7017 // things into explicit specializations.
7018 if (Member->getFriendObjectKind() != Decl::FOK_None) {
7019 // Preserve instantiation information.
7020 if (InstantiatedFrom && isa<CXXMethodDecl>(Member)) {
7021 cast<CXXMethodDecl>(Member)->setInstantiationOfMemberFunction(
7022 cast<CXXMethodDecl>(InstantiatedFrom),
7023 cast<CXXMethodDecl>(Instantiation)->getTemplateSpecializationKind());
7024 } else if (InstantiatedFrom && isa<CXXRecordDecl>(Member)) {
7025 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
7026 cast<CXXRecordDecl>(InstantiatedFrom),
7027 cast<CXXRecordDecl>(Instantiation)->getTemplateSpecializationKind());
7031 Previous.addDecl(Instantiation);
7035 // Make sure that this is a specialization of a member.
7036 if (!InstantiatedFrom) {
7037 Diag(Member->getLocation(), diag::err_spec_member_not_instantiated)
7039 Diag(Instantiation->getLocation(), diag::note_specialized_decl);
7043 // C++ [temp.expl.spec]p6:
7044 // If a template, a member template or the member of a class template is
7045 // explicitly specialized then that specialization shall be declared
7046 // before the first use of that specialization that would cause an implicit
7047 // instantiation to take place, in every translation unit in which such a
7048 // use occurs; no diagnostic is required.
7049 assert(MSInfo && "Member specialization info missing?");
7051 bool HasNoEffect = false;
7052 if (CheckSpecializationInstantiationRedecl(Member->getLocation(),
7053 TSK_ExplicitSpecialization,
7055 MSInfo->getTemplateSpecializationKind(),
7056 MSInfo->getPointOfInstantiation(),
7060 // Check the scope of this explicit specialization.
7061 if (CheckTemplateSpecializationScope(*this,
7063 Instantiation, Member->getLocation(),
7067 // Note that this is an explicit instantiation of a member.
7068 // the original declaration to note that it is an explicit specialization
7069 // (if it was previously an implicit instantiation). This latter step
7070 // makes bookkeeping easier.
7071 if (isa<FunctionDecl>(Member)) {
7072 FunctionDecl *InstantiationFunction = cast<FunctionDecl>(Instantiation);
7073 if (InstantiationFunction->getTemplateSpecializationKind() ==
7074 TSK_ImplicitInstantiation) {
7075 InstantiationFunction->setTemplateSpecializationKind(
7076 TSK_ExplicitSpecialization);
7077 InstantiationFunction->setLocation(Member->getLocation());
7080 cast<FunctionDecl>(Member)->setInstantiationOfMemberFunction(
7081 cast<CXXMethodDecl>(InstantiatedFrom),
7082 TSK_ExplicitSpecialization);
7083 MarkUnusedFileScopedDecl(InstantiationFunction);
7084 } else if (isa<VarDecl>(Member)) {
7085 VarDecl *InstantiationVar = cast<VarDecl>(Instantiation);
7086 if (InstantiationVar->getTemplateSpecializationKind() ==
7087 TSK_ImplicitInstantiation) {
7088 InstantiationVar->setTemplateSpecializationKind(
7089 TSK_ExplicitSpecialization);
7090 InstantiationVar->setLocation(Member->getLocation());
7093 cast<VarDecl>(Member)->setInstantiationOfStaticDataMember(
7094 cast<VarDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
7095 MarkUnusedFileScopedDecl(InstantiationVar);
7096 } else if (isa<CXXRecordDecl>(Member)) {
7097 CXXRecordDecl *InstantiationClass = cast<CXXRecordDecl>(Instantiation);
7098 if (InstantiationClass->getTemplateSpecializationKind() ==
7099 TSK_ImplicitInstantiation) {
7100 InstantiationClass->setTemplateSpecializationKind(
7101 TSK_ExplicitSpecialization);
7102 InstantiationClass->setLocation(Member->getLocation());
7105 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
7106 cast<CXXRecordDecl>(InstantiatedFrom),
7107 TSK_ExplicitSpecialization);
7109 assert(isa<EnumDecl>(Member) && "Only member enums remain");
7110 EnumDecl *InstantiationEnum = cast<EnumDecl>(Instantiation);
7111 if (InstantiationEnum->getTemplateSpecializationKind() ==
7112 TSK_ImplicitInstantiation) {
7113 InstantiationEnum->setTemplateSpecializationKind(
7114 TSK_ExplicitSpecialization);
7115 InstantiationEnum->setLocation(Member->getLocation());
7118 cast<EnumDecl>(Member)->setInstantiationOfMemberEnum(
7119 cast<EnumDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
7122 // Save the caller the trouble of having to figure out which declaration
7123 // this specialization matches.
7125 Previous.addDecl(Instantiation);
7129 /// \brief Check the scope of an explicit instantiation.
7131 /// \returns true if a serious error occurs, false otherwise.
7132 static bool CheckExplicitInstantiationScope(Sema &S, NamedDecl *D,
7133 SourceLocation InstLoc,
7134 bool WasQualifiedName) {
7135 DeclContext *OrigContext= D->getDeclContext()->getEnclosingNamespaceContext();
7136 DeclContext *CurContext = S.CurContext->getRedeclContext();
7138 if (CurContext->isRecord()) {
7139 S.Diag(InstLoc, diag::err_explicit_instantiation_in_class)
7144 // C++11 [temp.explicit]p3:
7145 // An explicit instantiation shall appear in an enclosing namespace of its
7146 // template. If the name declared in the explicit instantiation is an
7147 // unqualified name, the explicit instantiation shall appear in the
7148 // namespace where its template is declared or, if that namespace is inline
7149 // (7.3.1), any namespace from its enclosing namespace set.
7151 // This is DR275, which we do not retroactively apply to C++98/03.
7152 if (WasQualifiedName) {
7153 if (CurContext->Encloses(OrigContext))
7156 if (CurContext->InEnclosingNamespaceSetOf(OrigContext))
7160 if (NamespaceDecl *NS = dyn_cast<NamespaceDecl>(OrigContext)) {
7161 if (WasQualifiedName)
7163 S.getLangOpts().CPlusPlus11?
7164 diag::err_explicit_instantiation_out_of_scope :
7165 diag::warn_explicit_instantiation_out_of_scope_0x)
7169 S.getLangOpts().CPlusPlus11?
7170 diag::err_explicit_instantiation_unqualified_wrong_namespace :
7171 diag::warn_explicit_instantiation_unqualified_wrong_namespace_0x)
7175 S.getLangOpts().CPlusPlus11?
7176 diag::err_explicit_instantiation_must_be_global :
7177 diag::warn_explicit_instantiation_must_be_global_0x)
7179 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here);
7183 /// \brief Determine whether the given scope specifier has a template-id in it.
7184 static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec &SS) {
7188 // C++11 [temp.explicit]p3:
7189 // If the explicit instantiation is for a member function, a member class
7190 // or a static data member of a class template specialization, the name of
7191 // the class template specialization in the qualified-id for the member
7192 // name shall be a simple-template-id.
7194 // C++98 has the same restriction, just worded differently.
7195 for (NestedNameSpecifier *NNS = SS.getScopeRep(); NNS;
7196 NNS = NNS->getPrefix())
7197 if (const Type *T = NNS->getAsType())
7198 if (isa<TemplateSpecializationType>(T))
7204 // Explicit instantiation of a class template specialization
7206 Sema::ActOnExplicitInstantiation(Scope *S,
7207 SourceLocation ExternLoc,
7208 SourceLocation TemplateLoc,
7210 SourceLocation KWLoc,
7211 const CXXScopeSpec &SS,
7212 TemplateTy TemplateD,
7213 SourceLocation TemplateNameLoc,
7214 SourceLocation LAngleLoc,
7215 ASTTemplateArgsPtr TemplateArgsIn,
7216 SourceLocation RAngleLoc,
7217 AttributeList *Attr) {
7218 // Find the class template we're specializing
7219 TemplateName Name = TemplateD.get();
7220 TemplateDecl *TD = Name.getAsTemplateDecl();
7221 // Check that the specialization uses the same tag kind as the
7222 // original template.
7223 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
7224 assert(Kind != TTK_Enum &&
7225 "Invalid enum tag in class template explicit instantiation!");
7227 if (isa<TypeAliasTemplateDecl>(TD)) {
7228 Diag(KWLoc, diag::err_tag_reference_non_tag) << Kind;
7229 Diag(TD->getTemplatedDecl()->getLocation(),
7230 diag::note_previous_use);
7234 ClassTemplateDecl *ClassTemplate = cast<ClassTemplateDecl>(TD);
7236 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
7237 Kind, /*isDefinition*/false, KWLoc,
7238 ClassTemplate->getIdentifier())) {
7239 Diag(KWLoc, diag::err_use_with_wrong_tag)
7241 << FixItHint::CreateReplacement(KWLoc,
7242 ClassTemplate->getTemplatedDecl()->getKindName());
7243 Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
7244 diag::note_previous_use);
7245 Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
7248 // C++0x [temp.explicit]p2:
7249 // There are two forms of explicit instantiation: an explicit instantiation
7250 // definition and an explicit instantiation declaration. An explicit
7251 // instantiation declaration begins with the extern keyword. [...]
7252 TemplateSpecializationKind TSK = ExternLoc.isInvalid()
7253 ? TSK_ExplicitInstantiationDefinition
7254 : TSK_ExplicitInstantiationDeclaration;
7256 if (TSK == TSK_ExplicitInstantiationDeclaration) {
7257 // Check for dllexport class template instantiation declarations.
7258 for (AttributeList *A = Attr; A; A = A->getNext()) {
7259 if (A->getKind() == AttributeList::AT_DLLExport) {
7261 diag::warn_attribute_dllexport_explicit_instantiation_decl);
7262 Diag(A->getLoc(), diag::note_attribute);
7267 if (auto *A = ClassTemplate->getTemplatedDecl()->getAttr<DLLExportAttr>()) {
7269 diag::warn_attribute_dllexport_explicit_instantiation_decl);
7270 Diag(A->getLocation(), diag::note_attribute);
7274 // Translate the parser's template argument list in our AST format.
7275 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
7276 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
7278 // Check that the template argument list is well-formed for this
7280 SmallVector<TemplateArgument, 4> Converted;
7281 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
7282 TemplateArgs, false, Converted))
7285 // Find the class template specialization declaration that
7286 // corresponds to these arguments.
7287 void *InsertPos = nullptr;
7288 ClassTemplateSpecializationDecl *PrevDecl
7289 = ClassTemplate->findSpecialization(Converted, InsertPos);
7291 TemplateSpecializationKind PrevDecl_TSK
7292 = PrevDecl ? PrevDecl->getTemplateSpecializationKind() : TSK_Undeclared;
7294 // C++0x [temp.explicit]p2:
7295 // [...] An explicit instantiation shall appear in an enclosing
7296 // namespace of its template. [...]
7298 // This is C++ DR 275.
7299 if (CheckExplicitInstantiationScope(*this, ClassTemplate, TemplateNameLoc,
7303 ClassTemplateSpecializationDecl *Specialization = nullptr;
7305 bool HasNoEffect = false;
7307 if (CheckSpecializationInstantiationRedecl(TemplateNameLoc, TSK,
7308 PrevDecl, PrevDecl_TSK,
7309 PrevDecl->getPointOfInstantiation(),
7313 // Even though HasNoEffect == true means that this explicit instantiation
7314 // has no effect on semantics, we go on to put its syntax in the AST.
7316 if (PrevDecl_TSK == TSK_ImplicitInstantiation ||
7317 PrevDecl_TSK == TSK_Undeclared) {
7318 // Since the only prior class template specialization with these
7319 // arguments was referenced but not declared, reuse that
7320 // declaration node as our own, updating the source location
7321 // for the template name to reflect our new declaration.
7322 // (Other source locations will be updated later.)
7323 Specialization = PrevDecl;
7324 Specialization->setLocation(TemplateNameLoc);
7329 if (!Specialization) {
7330 // Create a new class template specialization declaration node for
7331 // this explicit specialization.
7333 = ClassTemplateSpecializationDecl::Create(Context, Kind,
7334 ClassTemplate->getDeclContext(),
7335 KWLoc, TemplateNameLoc,
7340 SetNestedNameSpecifier(Specialization, SS);
7342 if (!HasNoEffect && !PrevDecl) {
7343 // Insert the new specialization.
7344 ClassTemplate->AddSpecialization(Specialization, InsertPos);
7348 // Build the fully-sugared type for this explicit instantiation as
7349 // the user wrote in the explicit instantiation itself. This means
7350 // that we'll pretty-print the type retrieved from the
7351 // specialization's declaration the way that the user actually wrote
7352 // the explicit instantiation, rather than formatting the name based
7353 // on the "canonical" representation used to store the template
7354 // arguments in the specialization.
7355 TypeSourceInfo *WrittenTy
7356 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
7358 Context.getTypeDeclType(Specialization));
7359 Specialization->setTypeAsWritten(WrittenTy);
7361 // Set source locations for keywords.
7362 Specialization->setExternLoc(ExternLoc);
7363 Specialization->setTemplateKeywordLoc(TemplateLoc);
7364 Specialization->setRBraceLoc(SourceLocation());
7367 ProcessDeclAttributeList(S, Specialization, Attr);
7369 // Add the explicit instantiation into its lexical context. However,
7370 // since explicit instantiations are never found by name lookup, we
7371 // just put it into the declaration context directly.
7372 Specialization->setLexicalDeclContext(CurContext);
7373 CurContext->addDecl(Specialization);
7375 // Syntax is now OK, so return if it has no other effect on semantics.
7377 // Set the template specialization kind.
7378 Specialization->setTemplateSpecializationKind(TSK);
7379 return Specialization;
7382 // C++ [temp.explicit]p3:
7383 // A definition of a class template or class member template
7384 // shall be in scope at the point of the explicit instantiation of
7385 // the class template or class member template.
7387 // This check comes when we actually try to perform the
7389 ClassTemplateSpecializationDecl *Def
7390 = cast_or_null<ClassTemplateSpecializationDecl>(
7391 Specialization->getDefinition());
7393 InstantiateClassTemplateSpecialization(TemplateNameLoc, Specialization, TSK);
7394 else if (TSK == TSK_ExplicitInstantiationDefinition) {
7395 MarkVTableUsed(TemplateNameLoc, Specialization, true);
7396 Specialization->setPointOfInstantiation(Def->getPointOfInstantiation());
7399 // Instantiate the members of this class template specialization.
7400 Def = cast_or_null<ClassTemplateSpecializationDecl>(
7401 Specialization->getDefinition());
7403 TemplateSpecializationKind Old_TSK = Def->getTemplateSpecializationKind();
7405 // Fix a TSK_ExplicitInstantiationDeclaration followed by a
7406 // TSK_ExplicitInstantiationDefinition
7407 if (Old_TSK == TSK_ExplicitInstantiationDeclaration &&
7408 TSK == TSK_ExplicitInstantiationDefinition) {
7409 // FIXME: Need to notify the ASTMutationListener that we did this.
7410 Def->setTemplateSpecializationKind(TSK);
7412 if (!getDLLAttr(Def) && getDLLAttr(Specialization) &&
7413 Context.getTargetInfo().getCXXABI().isMicrosoft()) {
7414 // In the MS ABI, an explicit instantiation definition can add a dll
7415 // attribute to a template with a previous instantiation declaration.
7416 // MinGW doesn't allow this.
7417 auto *A = cast<InheritableAttr>(
7418 getDLLAttr(Specialization)->clone(getASTContext()));
7419 A->setInherited(true);
7421 checkClassLevelDLLAttribute(Def);
7423 // Propagate attribute to base class templates.
7424 for (auto &B : Def->bases()) {
7425 if (auto *BT = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
7426 B.getType()->getAsCXXRecordDecl()))
7427 propagateDLLAttrToBaseClassTemplate(Def, A, BT, B.getLocStart());
7432 InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK);
7435 // Set the template specialization kind.
7436 Specialization->setTemplateSpecializationKind(TSK);
7437 return Specialization;
7440 // Explicit instantiation of a member class of a class template.
7442 Sema::ActOnExplicitInstantiation(Scope *S,
7443 SourceLocation ExternLoc,
7444 SourceLocation TemplateLoc,
7446 SourceLocation KWLoc,
7448 IdentifierInfo *Name,
7449 SourceLocation NameLoc,
7450 AttributeList *Attr) {
7453 bool IsDependent = false;
7454 Decl *TagD = ActOnTag(S, TagSpec, Sema::TUK_Reference,
7455 KWLoc, SS, Name, NameLoc, Attr, AS_none,
7456 /*ModulePrivateLoc=*/SourceLocation(),
7457 MultiTemplateParamsArg(), Owned, IsDependent,
7458 SourceLocation(), false, TypeResult(),
7459 /*IsTypeSpecifier*/false);
7460 assert(!IsDependent && "explicit instantiation of dependent name not yet handled");
7465 TagDecl *Tag = cast<TagDecl>(TagD);
7466 assert(!Tag->isEnum() && "shouldn't see enumerations here");
7468 if (Tag->isInvalidDecl())
7471 CXXRecordDecl *Record = cast<CXXRecordDecl>(Tag);
7472 CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass();
7474 Diag(TemplateLoc, diag::err_explicit_instantiation_nontemplate_type)
7475 << Context.getTypeDeclType(Record);
7476 Diag(Record->getLocation(), diag::note_nontemplate_decl_here);
7480 // C++0x [temp.explicit]p2:
7481 // If the explicit instantiation is for a class or member class, the
7482 // elaborated-type-specifier in the declaration shall include a
7483 // simple-template-id.
7485 // C++98 has the same restriction, just worded differently.
7486 if (!ScopeSpecifierHasTemplateId(SS))
7487 Diag(TemplateLoc, diag::ext_explicit_instantiation_without_qualified_id)
7488 << Record << SS.getRange();
7490 // C++0x [temp.explicit]p2:
7491 // There are two forms of explicit instantiation: an explicit instantiation
7492 // definition and an explicit instantiation declaration. An explicit
7493 // instantiation declaration begins with the extern keyword. [...]
7494 TemplateSpecializationKind TSK
7495 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
7496 : TSK_ExplicitInstantiationDeclaration;
7498 // C++0x [temp.explicit]p2:
7499 // [...] An explicit instantiation shall appear in an enclosing
7500 // namespace of its template. [...]
7502 // This is C++ DR 275.
7503 CheckExplicitInstantiationScope(*this, Record, NameLoc, true);
7505 // Verify that it is okay to explicitly instantiate here.
7506 CXXRecordDecl *PrevDecl
7507 = cast_or_null<CXXRecordDecl>(Record->getPreviousDecl());
7508 if (!PrevDecl && Record->getDefinition())
7511 MemberSpecializationInfo *MSInfo = PrevDecl->getMemberSpecializationInfo();
7512 bool HasNoEffect = false;
7513 assert(MSInfo && "No member specialization information?");
7514 if (CheckSpecializationInstantiationRedecl(TemplateLoc, TSK,
7516 MSInfo->getTemplateSpecializationKind(),
7517 MSInfo->getPointOfInstantiation(),
7524 CXXRecordDecl *RecordDef
7525 = cast_or_null<CXXRecordDecl>(Record->getDefinition());
7527 // C++ [temp.explicit]p3:
7528 // A definition of a member class of a class template shall be in scope
7529 // at the point of an explicit instantiation of the member class.
7531 = cast_or_null<CXXRecordDecl>(Pattern->getDefinition());
7533 Diag(TemplateLoc, diag::err_explicit_instantiation_undefined_member)
7534 << 0 << Record->getDeclName() << Record->getDeclContext();
7535 Diag(Pattern->getLocation(), diag::note_forward_declaration)
7539 if (InstantiateClass(NameLoc, Record, Def,
7540 getTemplateInstantiationArgs(Record),
7544 RecordDef = cast_or_null<CXXRecordDecl>(Record->getDefinition());
7550 // Instantiate all of the members of the class.
7551 InstantiateClassMembers(NameLoc, RecordDef,
7552 getTemplateInstantiationArgs(Record), TSK);
7554 if (TSK == TSK_ExplicitInstantiationDefinition)
7555 MarkVTableUsed(NameLoc, RecordDef, true);
7557 // FIXME: We don't have any representation for explicit instantiations of
7558 // member classes. Such a representation is not needed for compilation, but it
7559 // should be available for clients that want to see all of the declarations in
7564 DeclResult Sema::ActOnExplicitInstantiation(Scope *S,
7565 SourceLocation ExternLoc,
7566 SourceLocation TemplateLoc,
7568 // Explicit instantiations always require a name.
7569 // TODO: check if/when DNInfo should replace Name.
7570 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
7571 DeclarationName Name = NameInfo.getName();
7573 if (!D.isInvalidType())
7574 Diag(D.getDeclSpec().getLocStart(),
7575 diag::err_explicit_instantiation_requires_name)
7576 << D.getDeclSpec().getSourceRange()
7577 << D.getSourceRange();
7582 // The scope passed in may not be a decl scope. Zip up the scope tree until
7583 // we find one that is.
7584 while ((S->getFlags() & Scope::DeclScope) == 0 ||
7585 (S->getFlags() & Scope::TemplateParamScope) != 0)
7588 // Determine the type of the declaration.
7589 TypeSourceInfo *T = GetTypeForDeclarator(D, S);
7590 QualType R = T->getType();
7595 // A storage-class-specifier shall not be specified in [...] an explicit
7596 // instantiation (14.7.2) directive.
7597 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
7598 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_of_typedef)
7601 } else if (D.getDeclSpec().getStorageClassSpec()
7602 != DeclSpec::SCS_unspecified) {
7603 // Complain about then remove the storage class specifier.
7604 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_storage_class)
7605 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
7607 D.getMutableDeclSpec().ClearStorageClassSpecs();
7610 // C++0x [temp.explicit]p1:
7611 // [...] An explicit instantiation of a function template shall not use the
7612 // inline or constexpr specifiers.
7613 // Presumably, this also applies to member functions of class templates as
7615 if (D.getDeclSpec().isInlineSpecified())
7616 Diag(D.getDeclSpec().getInlineSpecLoc(),
7617 getLangOpts().CPlusPlus11 ?
7618 diag::err_explicit_instantiation_inline :
7619 diag::warn_explicit_instantiation_inline_0x)
7620 << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
7621 if (D.getDeclSpec().isConstexprSpecified() && R->isFunctionType())
7622 // FIXME: Add a fix-it to remove the 'constexpr' and add a 'const' if one is
7623 // not already specified.
7624 Diag(D.getDeclSpec().getConstexprSpecLoc(),
7625 diag::err_explicit_instantiation_constexpr);
7627 // C++0x [temp.explicit]p2:
7628 // There are two forms of explicit instantiation: an explicit instantiation
7629 // definition and an explicit instantiation declaration. An explicit
7630 // instantiation declaration begins with the extern keyword. [...]
7631 TemplateSpecializationKind TSK
7632 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
7633 : TSK_ExplicitInstantiationDeclaration;
7635 LookupResult Previous(*this, NameInfo, LookupOrdinaryName);
7636 LookupParsedName(Previous, S, &D.getCXXScopeSpec());
7638 if (!R->isFunctionType()) {
7639 // C++ [temp.explicit]p1:
7640 // A [...] static data member of a class template can be explicitly
7641 // instantiated from the member definition associated with its class
7643 // C++1y [temp.explicit]p1:
7644 // A [...] variable [...] template specialization can be explicitly
7645 // instantiated from its template.
7646 if (Previous.isAmbiguous())
7649 VarDecl *Prev = Previous.getAsSingle<VarDecl>();
7650 VarTemplateDecl *PrevTemplate = Previous.getAsSingle<VarTemplateDecl>();
7652 if (!PrevTemplate) {
7653 if (!Prev || !Prev->isStaticDataMember()) {
7654 // We expect to see a data data member here.
7655 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_not_known)
7657 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
7659 Diag((*P)->getLocation(), diag::note_explicit_instantiation_here);
7663 if (!Prev->getInstantiatedFromStaticDataMember()) {
7664 // FIXME: Check for explicit specialization?
7665 Diag(D.getIdentifierLoc(),
7666 diag::err_explicit_instantiation_data_member_not_instantiated)
7668 Diag(Prev->getLocation(), diag::note_explicit_instantiation_here);
7669 // FIXME: Can we provide a note showing where this was declared?
7673 // Explicitly instantiate a variable template.
7675 // C++1y [dcl.spec.auto]p6:
7676 // ... A program that uses auto or decltype(auto) in a context not
7677 // explicitly allowed in this section is ill-formed.
7679 // This includes auto-typed variable template instantiations.
7680 if (R->isUndeducedType()) {
7681 Diag(T->getTypeLoc().getLocStart(),
7682 diag::err_auto_not_allowed_var_inst);
7686 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId) {
7687 // C++1y [temp.explicit]p3:
7688 // If the explicit instantiation is for a variable, the unqualified-id
7689 // in the declaration shall be a template-id.
7690 Diag(D.getIdentifierLoc(),
7691 diag::err_explicit_instantiation_without_template_id)
7693 Diag(PrevTemplate->getLocation(),
7694 diag::note_explicit_instantiation_here);
7698 // Translate the parser's template argument list into our AST format.
7699 TemplateArgumentListInfo TemplateArgs =
7700 makeTemplateArgumentListInfo(*this, *D.getName().TemplateId);
7702 DeclResult Res = CheckVarTemplateId(PrevTemplate, TemplateLoc,
7703 D.getIdentifierLoc(), TemplateArgs);
7704 if (Res.isInvalid())
7707 // Ignore access control bits, we don't need them for redeclaration
7709 Prev = cast<VarDecl>(Res.get());
7712 // C++0x [temp.explicit]p2:
7713 // If the explicit instantiation is for a member function, a member class
7714 // or a static data member of a class template specialization, the name of
7715 // the class template specialization in the qualified-id for the member
7716 // name shall be a simple-template-id.
7718 // C++98 has the same restriction, just worded differently.
7720 // This does not apply to variable template specializations, where the
7721 // template-id is in the unqualified-id instead.
7722 if (!ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()) && !PrevTemplate)
7723 Diag(D.getIdentifierLoc(),
7724 diag::ext_explicit_instantiation_without_qualified_id)
7725 << Prev << D.getCXXScopeSpec().getRange();
7727 // Check the scope of this explicit instantiation.
7728 CheckExplicitInstantiationScope(*this, Prev, D.getIdentifierLoc(), true);
7730 // Verify that it is okay to explicitly instantiate here.
7731 TemplateSpecializationKind PrevTSK = Prev->getTemplateSpecializationKind();
7732 SourceLocation POI = Prev->getPointOfInstantiation();
7733 bool HasNoEffect = false;
7734 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, Prev,
7735 PrevTSK, POI, HasNoEffect))
7739 // Instantiate static data member or variable template.
7741 Prev->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
7743 // Merge attributes.
7744 if (AttributeList *Attr = D.getDeclSpec().getAttributes().getList())
7745 ProcessDeclAttributeList(S, Prev, Attr);
7747 if (TSK == TSK_ExplicitInstantiationDefinition)
7748 InstantiateVariableDefinition(D.getIdentifierLoc(), Prev);
7751 // Check the new variable specialization against the parsed input.
7752 if (PrevTemplate && Prev && !Context.hasSameType(Prev->getType(), R)) {
7753 Diag(T->getTypeLoc().getLocStart(),
7754 diag::err_invalid_var_template_spec_type)
7755 << 0 << PrevTemplate << R << Prev->getType();
7756 Diag(PrevTemplate->getLocation(), diag::note_template_declared_here)
7757 << 2 << PrevTemplate->getDeclName();
7761 // FIXME: Create an ExplicitInstantiation node?
7762 return (Decl*) nullptr;
7765 // If the declarator is a template-id, translate the parser's template
7766 // argument list into our AST format.
7767 bool HasExplicitTemplateArgs = false;
7768 TemplateArgumentListInfo TemplateArgs;
7769 if (D.getName().getKind() == UnqualifiedId::IK_TemplateId) {
7770 TemplateArgs = makeTemplateArgumentListInfo(*this, *D.getName().TemplateId);
7771 HasExplicitTemplateArgs = true;
7774 // C++ [temp.explicit]p1:
7775 // A [...] function [...] can be explicitly instantiated from its template.
7776 // A member function [...] of a class template can be explicitly
7777 // instantiated from the member definition associated with its class
7779 UnresolvedSet<8> Matches;
7780 TemplateSpecCandidateSet FailedCandidates(D.getIdentifierLoc());
7781 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
7783 NamedDecl *Prev = *P;
7784 if (!HasExplicitTemplateArgs) {
7785 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Prev)) {
7786 QualType Adjusted = adjustCCAndNoReturn(R, Method->getType());
7787 if (Context.hasSameUnqualifiedType(Method->getType(), Adjusted)) {
7790 Matches.addDecl(Method, P.getAccess());
7791 if (Method->getTemplateSpecializationKind() == TSK_Undeclared)
7797 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Prev);
7801 TemplateDeductionInfo Info(FailedCandidates.getLocation());
7802 FunctionDecl *Specialization = nullptr;
7803 if (TemplateDeductionResult TDK
7804 = DeduceTemplateArguments(FunTmpl,
7805 (HasExplicitTemplateArgs ? &TemplateArgs
7807 R, Specialization, Info)) {
7808 // Keep track of almost-matches.
7809 FailedCandidates.addCandidate()
7810 .set(FunTmpl->getTemplatedDecl(),
7811 MakeDeductionFailureInfo(Context, TDK, Info));
7816 Matches.addDecl(Specialization, P.getAccess());
7819 // Find the most specialized function template specialization.
7820 UnresolvedSetIterator Result = getMostSpecialized(
7821 Matches.begin(), Matches.end(), FailedCandidates,
7822 D.getIdentifierLoc(),
7823 PDiag(diag::err_explicit_instantiation_not_known) << Name,
7824 PDiag(diag::err_explicit_instantiation_ambiguous) << Name,
7825 PDiag(diag::note_explicit_instantiation_candidate));
7827 if (Result == Matches.end())
7830 // Ignore access control bits, we don't need them for redeclaration checking.
7831 FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
7833 // C++11 [except.spec]p4
7834 // In an explicit instantiation an exception-specification may be specified,
7835 // but is not required.
7836 // If an exception-specification is specified in an explicit instantiation
7837 // directive, it shall be compatible with the exception-specifications of
7838 // other declarations of that function.
7839 if (auto *FPT = R->getAs<FunctionProtoType>())
7840 if (FPT->hasExceptionSpec()) {
7842 diag::err_mismatched_exception_spec_explicit_instantiation;
7843 if (getLangOpts().MicrosoftExt)
7844 DiagID = diag::ext_mismatched_exception_spec_explicit_instantiation;
7845 bool Result = CheckEquivalentExceptionSpec(
7846 PDiag(DiagID) << Specialization->getType(),
7847 PDiag(diag::note_explicit_instantiation_here),
7848 Specialization->getType()->getAs<FunctionProtoType>(),
7849 Specialization->getLocation(), FPT, D.getLocStart());
7850 // In Microsoft mode, mismatching exception specifications just cause a
7852 if (!getLangOpts().MicrosoftExt && Result)
7856 if (Specialization->getTemplateSpecializationKind() == TSK_Undeclared) {
7857 Diag(D.getIdentifierLoc(),
7858 diag::err_explicit_instantiation_member_function_not_instantiated)
7860 << (Specialization->getTemplateSpecializationKind() ==
7861 TSK_ExplicitSpecialization);
7862 Diag(Specialization->getLocation(), diag::note_explicit_instantiation_here);
7866 FunctionDecl *PrevDecl = Specialization->getPreviousDecl();
7867 if (!PrevDecl && Specialization->isThisDeclarationADefinition())
7868 PrevDecl = Specialization;
7871 bool HasNoEffect = false;
7872 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK,
7874 PrevDecl->getTemplateSpecializationKind(),
7875 PrevDecl->getPointOfInstantiation(),
7879 // FIXME: We may still want to build some representation of this
7880 // explicit specialization.
7882 return (Decl*) nullptr;
7885 Specialization->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
7886 AttributeList *Attr = D.getDeclSpec().getAttributes().getList();
7888 ProcessDeclAttributeList(S, Specialization, Attr);
7890 if (Specialization->isDefined()) {
7891 // Let the ASTConsumer know that this function has been explicitly
7892 // instantiated now, and its linkage might have changed.
7893 Consumer.HandleTopLevelDecl(DeclGroupRef(Specialization));
7894 } else if (TSK == TSK_ExplicitInstantiationDefinition)
7895 InstantiateFunctionDefinition(D.getIdentifierLoc(), Specialization);
7897 // C++0x [temp.explicit]p2:
7898 // If the explicit instantiation is for a member function, a member class
7899 // or a static data member of a class template specialization, the name of
7900 // the class template specialization in the qualified-id for the member
7901 // name shall be a simple-template-id.
7903 // C++98 has the same restriction, just worded differently.
7904 FunctionTemplateDecl *FunTmpl = Specialization->getPrimaryTemplate();
7905 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId && !FunTmpl &&
7906 D.getCXXScopeSpec().isSet() &&
7907 !ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()))
7908 Diag(D.getIdentifierLoc(),
7909 diag::ext_explicit_instantiation_without_qualified_id)
7910 << Specialization << D.getCXXScopeSpec().getRange();
7912 CheckExplicitInstantiationScope(*this,
7913 FunTmpl? (NamedDecl *)FunTmpl
7914 : Specialization->getInstantiatedFromMemberFunction(),
7915 D.getIdentifierLoc(),
7916 D.getCXXScopeSpec().isSet());
7918 // FIXME: Create some kind of ExplicitInstantiationDecl here.
7919 return (Decl*) nullptr;
7923 Sema::ActOnDependentTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
7924 const CXXScopeSpec &SS, IdentifierInfo *Name,
7925 SourceLocation TagLoc, SourceLocation NameLoc) {
7926 // This has to hold, because SS is expected to be defined.
7927 assert(Name && "Expected a name in a dependent tag");
7929 NestedNameSpecifier *NNS = SS.getScopeRep();
7933 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
7935 if (TUK == TUK_Declaration || TUK == TUK_Definition) {
7936 Diag(NameLoc, diag::err_dependent_tag_decl)
7937 << (TUK == TUK_Definition) << Kind << SS.getRange();
7941 // Create the resulting type.
7942 ElaboratedTypeKeyword Kwd = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
7943 QualType Result = Context.getDependentNameType(Kwd, NNS, Name);
7945 // Create type-source location information for this type.
7947 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(Result);
7948 TL.setElaboratedKeywordLoc(TagLoc);
7949 TL.setQualifierLoc(SS.getWithLocInContext(Context));
7950 TL.setNameLoc(NameLoc);
7951 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
7955 Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc,
7956 const CXXScopeSpec &SS, const IdentifierInfo &II,
7957 SourceLocation IdLoc) {
7961 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
7963 getLangOpts().CPlusPlus11 ?
7964 diag::warn_cxx98_compat_typename_outside_of_template :
7965 diag::ext_typename_outside_of_template)
7966 << FixItHint::CreateRemoval(TypenameLoc);
7968 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
7969 QualType T = CheckTypenameType(TypenameLoc.isValid()? ETK_Typename : ETK_None,
7970 TypenameLoc, QualifierLoc, II, IdLoc);
7974 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
7975 if (isa<DependentNameType>(T)) {
7976 DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
7977 TL.setElaboratedKeywordLoc(TypenameLoc);
7978 TL.setQualifierLoc(QualifierLoc);
7979 TL.setNameLoc(IdLoc);
7981 ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>();
7982 TL.setElaboratedKeywordLoc(TypenameLoc);
7983 TL.setQualifierLoc(QualifierLoc);
7984 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
7987 return CreateParsedType(T, TSI);
7991 Sema::ActOnTypenameType(Scope *S,
7992 SourceLocation TypenameLoc,
7993 const CXXScopeSpec &SS,
7994 SourceLocation TemplateKWLoc,
7995 TemplateTy TemplateIn,
7996 SourceLocation TemplateNameLoc,
7997 SourceLocation LAngleLoc,
7998 ASTTemplateArgsPtr TemplateArgsIn,
7999 SourceLocation RAngleLoc) {
8000 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
8002 getLangOpts().CPlusPlus11 ?
8003 diag::warn_cxx98_compat_typename_outside_of_template :
8004 diag::ext_typename_outside_of_template)
8005 << FixItHint::CreateRemoval(TypenameLoc);
8007 // Translate the parser's template argument list in our AST format.
8008 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
8009 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
8011 TemplateName Template = TemplateIn.get();
8012 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
8013 // Construct a dependent template specialization type.
8014 assert(DTN && "dependent template has non-dependent name?");
8015 assert(DTN->getQualifier() == SS.getScopeRep());
8016 QualType T = Context.getDependentTemplateSpecializationType(ETK_Typename,
8017 DTN->getQualifier(),
8018 DTN->getIdentifier(),
8021 // Create source-location information for this type.
8022 TypeLocBuilder Builder;
8023 DependentTemplateSpecializationTypeLoc SpecTL
8024 = Builder.push<DependentTemplateSpecializationTypeLoc>(T);
8025 SpecTL.setElaboratedKeywordLoc(TypenameLoc);
8026 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
8027 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
8028 SpecTL.setTemplateNameLoc(TemplateNameLoc);
8029 SpecTL.setLAngleLoc(LAngleLoc);
8030 SpecTL.setRAngleLoc(RAngleLoc);
8031 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
8032 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
8033 return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
8036 QualType T = CheckTemplateIdType(Template, TemplateNameLoc, TemplateArgs);
8040 // Provide source-location information for the template specialization type.
8041 TypeLocBuilder Builder;
8042 TemplateSpecializationTypeLoc SpecTL
8043 = Builder.push<TemplateSpecializationTypeLoc>(T);
8044 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
8045 SpecTL.setTemplateNameLoc(TemplateNameLoc);
8046 SpecTL.setLAngleLoc(LAngleLoc);
8047 SpecTL.setRAngleLoc(RAngleLoc);
8048 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
8049 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
8051 T = Context.getElaboratedType(ETK_Typename, SS.getScopeRep(), T);
8052 ElaboratedTypeLoc TL = Builder.push<ElaboratedTypeLoc>(T);
8053 TL.setElaboratedKeywordLoc(TypenameLoc);
8054 TL.setQualifierLoc(SS.getWithLocInContext(Context));
8056 TypeSourceInfo *TSI = Builder.getTypeSourceInfo(Context, T);
8057 return CreateParsedType(T, TSI);
8061 /// Determine whether this failed name lookup should be treated as being
8062 /// disabled by a usage of std::enable_if.
8063 static bool isEnableIf(NestedNameSpecifierLoc NNS, const IdentifierInfo &II,
8064 SourceRange &CondRange) {
8065 // We must be looking for a ::type...
8066 if (!II.isStr("type"))
8069 // ... within an explicitly-written template specialization...
8070 if (!NNS || !NNS.getNestedNameSpecifier()->getAsType())
8072 TypeLoc EnableIfTy = NNS.getTypeLoc();
8073 TemplateSpecializationTypeLoc EnableIfTSTLoc =
8074 EnableIfTy.getAs<TemplateSpecializationTypeLoc>();
8075 if (!EnableIfTSTLoc || EnableIfTSTLoc.getNumArgs() == 0)
8077 const TemplateSpecializationType *EnableIfTST =
8078 cast<TemplateSpecializationType>(EnableIfTSTLoc.getTypePtr());
8080 // ... which names a complete class template declaration...
8081 const TemplateDecl *EnableIfDecl =
8082 EnableIfTST->getTemplateName().getAsTemplateDecl();
8083 if (!EnableIfDecl || EnableIfTST->isIncompleteType())
8086 // ... called "enable_if".
8087 const IdentifierInfo *EnableIfII =
8088 EnableIfDecl->getDeclName().getAsIdentifierInfo();
8089 if (!EnableIfII || !EnableIfII->isStr("enable_if"))
8092 // Assume the first template argument is the condition.
8093 CondRange = EnableIfTSTLoc.getArgLoc(0).getSourceRange();
8097 /// \brief Build the type that describes a C++ typename specifier,
8098 /// e.g., "typename T::type".
8100 Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword,
8101 SourceLocation KeywordLoc,
8102 NestedNameSpecifierLoc QualifierLoc,
8103 const IdentifierInfo &II,
8104 SourceLocation IILoc) {
8106 SS.Adopt(QualifierLoc);
8108 DeclContext *Ctx = computeDeclContext(SS);
8110 // If the nested-name-specifier is dependent and couldn't be
8111 // resolved to a type, build a typename type.
8112 assert(QualifierLoc.getNestedNameSpecifier()->isDependent());
8113 return Context.getDependentNameType(Keyword,
8114 QualifierLoc.getNestedNameSpecifier(),
8118 // If the nested-name-specifier refers to the current instantiation,
8119 // the "typename" keyword itself is superfluous. In C++03, the
8120 // program is actually ill-formed. However, DR 382 (in C++0x CD1)
8121 // allows such extraneous "typename" keywords, and we retroactively
8122 // apply this DR to C++03 code with only a warning. In any case we continue.
8124 if (RequireCompleteDeclContext(SS, Ctx))
8127 DeclarationName Name(&II);
8128 LookupResult Result(*this, Name, IILoc, LookupOrdinaryName);
8129 LookupQualifiedName(Result, Ctx, SS);
8130 unsigned DiagID = 0;
8131 Decl *Referenced = nullptr;
8132 switch (Result.getResultKind()) {
8133 case LookupResult::NotFound: {
8134 // If we're looking up 'type' within a template named 'enable_if', produce
8135 // a more specific diagnostic.
8136 SourceRange CondRange;
8137 if (isEnableIf(QualifierLoc, II, CondRange)) {
8138 Diag(CondRange.getBegin(), diag::err_typename_nested_not_found_enable_if)
8139 << Ctx << CondRange;
8143 DiagID = diag::err_typename_nested_not_found;
8147 case LookupResult::FoundUnresolvedValue: {
8148 // We found a using declaration that is a value. Most likely, the using
8149 // declaration itself is meant to have the 'typename' keyword.
8150 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
8152 Diag(IILoc, diag::err_typename_refers_to_using_value_decl)
8153 << Name << Ctx << FullRange;
8154 if (UnresolvedUsingValueDecl *Using
8155 = dyn_cast<UnresolvedUsingValueDecl>(Result.getRepresentativeDecl())){
8156 SourceLocation Loc = Using->getQualifierLoc().getBeginLoc();
8157 Diag(Loc, diag::note_using_value_decl_missing_typename)
8158 << FixItHint::CreateInsertion(Loc, "typename ");
8161 // Fall through to create a dependent typename type, from which we can recover
8164 case LookupResult::NotFoundInCurrentInstantiation:
8165 // Okay, it's a member of an unknown instantiation.
8166 return Context.getDependentNameType(Keyword,
8167 QualifierLoc.getNestedNameSpecifier(),
8170 case LookupResult::Found:
8171 if (TypeDecl *Type = dyn_cast<TypeDecl>(Result.getFoundDecl())) {
8172 // We found a type. Build an ElaboratedType, since the
8173 // typename-specifier was just sugar.
8174 MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
8175 return Context.getElaboratedType(ETK_Typename,
8176 QualifierLoc.getNestedNameSpecifier(),
8177 Context.getTypeDeclType(Type));
8180 DiagID = diag::err_typename_nested_not_type;
8181 Referenced = Result.getFoundDecl();
8184 case LookupResult::FoundOverloaded:
8185 DiagID = diag::err_typename_nested_not_type;
8186 Referenced = *Result.begin();
8189 case LookupResult::Ambiguous:
8193 // If we get here, it's because name lookup did not find a
8194 // type. Emit an appropriate diagnostic and return an error.
8195 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
8197 Diag(IILoc, DiagID) << FullRange << Name << Ctx;
8199 Diag(Referenced->getLocation(), diag::note_typename_refers_here)
8205 // See Sema::RebuildTypeInCurrentInstantiation
8206 class CurrentInstantiationRebuilder
8207 : public TreeTransform<CurrentInstantiationRebuilder> {
8209 DeclarationName Entity;
8212 typedef TreeTransform<CurrentInstantiationRebuilder> inherited;
8214 CurrentInstantiationRebuilder(Sema &SemaRef,
8216 DeclarationName Entity)
8217 : TreeTransform<CurrentInstantiationRebuilder>(SemaRef),
8218 Loc(Loc), Entity(Entity) { }
8220 /// \brief Determine whether the given type \p T has already been
8223 /// For the purposes of type reconstruction, a type has already been
8224 /// transformed if it is NULL or if it is not dependent.
8225 bool AlreadyTransformed(QualType T) {
8226 return T.isNull() || !T->isDependentType();
8229 /// \brief Returns the location of the entity whose type is being
8231 SourceLocation getBaseLocation() { return Loc; }
8233 /// \brief Returns the name of the entity whose type is being rebuilt.
8234 DeclarationName getBaseEntity() { return Entity; }
8236 /// \brief Sets the "base" location and entity when that
8237 /// information is known based on another transformation.
8238 void setBase(SourceLocation Loc, DeclarationName Entity) {
8240 this->Entity = Entity;
8243 ExprResult TransformLambdaExpr(LambdaExpr *E) {
8244 // Lambdas never need to be transformed.
8250 /// \brief Rebuilds a type within the context of the current instantiation.
8252 /// The type \p T is part of the type of an out-of-line member definition of
8253 /// a class template (or class template partial specialization) that was parsed
8254 /// and constructed before we entered the scope of the class template (or
8255 /// partial specialization thereof). This routine will rebuild that type now
8256 /// that we have entered the declarator's scope, which may produce different
8257 /// canonical types, e.g.,
8260 /// template<typename T>
8262 /// typedef T* pointer;
8266 /// template<typename T>
8267 /// typename X<T>::pointer X<T>::data() { ... }
8270 /// Here, the type "typename X<T>::pointer" will be created as a DependentNameType,
8271 /// since we do not know that we can look into X<T> when we parsed the type.
8272 /// This function will rebuild the type, performing the lookup of "pointer"
8273 /// in X<T> and returning an ElaboratedType whose canonical type is the same
8274 /// as the canonical type of T*, allowing the return types of the out-of-line
8275 /// definition and the declaration to match.
8276 TypeSourceInfo *Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo *T,
8278 DeclarationName Name) {
8279 if (!T || !T->getType()->isDependentType())
8282 CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name);
8283 return Rebuilder.TransformType(T);
8286 ExprResult Sema::RebuildExprInCurrentInstantiation(Expr *E) {
8287 CurrentInstantiationRebuilder Rebuilder(*this, E->getExprLoc(),
8289 return Rebuilder.TransformExpr(E);
8292 bool Sema::RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS) {
8296 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
8297 CurrentInstantiationRebuilder Rebuilder(*this, SS.getRange().getBegin(),
8299 NestedNameSpecifierLoc Rebuilt
8300 = Rebuilder.TransformNestedNameSpecifierLoc(QualifierLoc);
8308 /// \brief Rebuild the template parameters now that we know we're in a current
8310 bool Sema::RebuildTemplateParamsInCurrentInstantiation(
8311 TemplateParameterList *Params) {
8312 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
8313 Decl *Param = Params->getParam(I);
8315 // There is nothing to rebuild in a type parameter.
8316 if (isa<TemplateTypeParmDecl>(Param))
8319 // Rebuild the template parameter list of a template template parameter.
8320 if (TemplateTemplateParmDecl *TTP
8321 = dyn_cast<TemplateTemplateParmDecl>(Param)) {
8322 if (RebuildTemplateParamsInCurrentInstantiation(
8323 TTP->getTemplateParameters()))
8329 // Rebuild the type of a non-type template parameter.
8330 NonTypeTemplateParmDecl *NTTP = cast<NonTypeTemplateParmDecl>(Param);
8331 TypeSourceInfo *NewTSI
8332 = RebuildTypeInCurrentInstantiation(NTTP->getTypeSourceInfo(),
8333 NTTP->getLocation(),
8334 NTTP->getDeclName());
8338 if (NewTSI != NTTP->getTypeSourceInfo()) {
8339 NTTP->setTypeSourceInfo(NewTSI);
8340 NTTP->setType(NewTSI->getType());
8347 /// \brief Produces a formatted string that describes the binding of
8348 /// template parameters to template arguments.
8350 Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
8351 const TemplateArgumentList &Args) {
8352 return getTemplateArgumentBindingsText(Params, Args.data(), Args.size());
8356 Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
8357 const TemplateArgument *Args,
8359 SmallString<128> Str;
8360 llvm::raw_svector_ostream Out(Str);
8362 if (!Params || Params->size() == 0 || NumArgs == 0)
8363 return std::string();
8365 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
8374 if (const IdentifierInfo *Id = Params->getParam(I)->getIdentifier()) {
8375 Out << Id->getName();
8381 Args[I].print(getPrintingPolicy(), Out);
8388 void Sema::MarkAsLateParsedTemplate(FunctionDecl *FD, Decl *FnD,
8389 CachedTokens &Toks) {
8393 LateParsedTemplate *LPT = new LateParsedTemplate;
8395 // Take tokens to avoid allocations
8396 LPT->Toks.swap(Toks);
8398 LateParsedTemplateMap.insert(std::make_pair(FD, LPT));
8400 FD->setLateTemplateParsed(true);
8403 void Sema::UnmarkAsLateParsedTemplate(FunctionDecl *FD) {
8406 FD->setLateTemplateParsed(false);
8409 bool Sema::IsInsideALocalClassWithinATemplateFunction() {
8410 DeclContext *DC = CurContext;
8413 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(CurContext)) {
8414 const FunctionDecl *FD = RD->isLocalClass();
8415 return (FD && FD->getTemplatedKind() != FunctionDecl::TK_NonTemplate);
8416 } else if (DC->isTranslationUnit() || DC->isNamespace())
8419 DC = DC->getParent();