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)) {
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, false);
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())
655 // FIXME: Keep the type prior to promotion?
656 return Context.getArrayDecayedType(T);
657 else if (T->isFunctionType())
658 // FIXME: Keep the type prior to promotion?
659 return Context.getPointerType(T);
661 Diag(Loc, diag::err_template_nontype_parm_bad_type)
667 Decl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
670 SourceLocation EqualLoc,
672 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
673 QualType T = TInfo->getType();
675 assert(S->isTemplateParamScope() &&
676 "Non-type template parameter not in template parameter scope!");
677 bool Invalid = false;
679 T = CheckNonTypeTemplateParameterType(T, D.getIdentifierLoc());
681 T = Context.IntTy; // Recover with an 'int' type.
685 IdentifierInfo *ParamName = D.getIdentifier();
686 bool IsParameterPack = D.hasEllipsis();
687 NonTypeTemplateParmDecl *Param
688 = NonTypeTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
690 D.getIdentifierLoc(),
691 Depth, Position, ParamName, T,
692 IsParameterPack, TInfo);
693 Param->setAccess(AS_public);
696 Param->setInvalidDecl();
699 maybeDiagnoseTemplateParameterShadow(*this, S, D.getIdentifierLoc(),
702 // Add the template parameter into the current scope.
704 IdResolver.AddDecl(Param);
707 // C++0x [temp.param]p9:
708 // A default template-argument may be specified for any kind of
709 // template-parameter that is not a template parameter pack.
710 if (Default && IsParameterPack) {
711 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
715 // Check the well-formedness of the default template argument, if provided.
717 // Check for unexpanded parameter packs.
718 if (DiagnoseUnexpandedParameterPack(Default, UPPC_DefaultArgument))
721 TemplateArgument Converted;
722 ExprResult DefaultRes = CheckTemplateArgument(Param, Param->getType(), Default, Converted);
723 if (DefaultRes.isInvalid()) {
724 Param->setInvalidDecl();
727 Default = DefaultRes.get();
729 Param->setDefaultArgument(Default, false);
735 /// ActOnTemplateTemplateParameter - Called when a C++ template template
736 /// parameter (e.g. T in template <template \<typename> class T> class array)
737 /// has been parsed. S is the current scope.
738 Decl *Sema::ActOnTemplateTemplateParameter(Scope* S,
739 SourceLocation TmpLoc,
740 TemplateParameterList *Params,
741 SourceLocation EllipsisLoc,
742 IdentifierInfo *Name,
743 SourceLocation NameLoc,
746 SourceLocation EqualLoc,
747 ParsedTemplateArgument Default) {
748 assert(S->isTemplateParamScope() &&
749 "Template template parameter not in template parameter scope!");
751 // Construct the parameter object.
752 bool IsParameterPack = EllipsisLoc.isValid();
753 TemplateTemplateParmDecl *Param =
754 TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
755 NameLoc.isInvalid()? TmpLoc : NameLoc,
756 Depth, Position, IsParameterPack,
758 Param->setAccess(AS_public);
760 // If the template template parameter has a name, then link the identifier
761 // into the scope and lookup mechanisms.
763 maybeDiagnoseTemplateParameterShadow(*this, S, NameLoc, Name);
766 IdResolver.AddDecl(Param);
769 if (Params->size() == 0) {
770 Diag(Param->getLocation(), diag::err_template_template_parm_no_parms)
771 << SourceRange(Params->getLAngleLoc(), Params->getRAngleLoc());
772 Param->setInvalidDecl();
775 // C++0x [temp.param]p9:
776 // A default template-argument may be specified for any kind of
777 // template-parameter that is not a template parameter pack.
778 if (IsParameterPack && !Default.isInvalid()) {
779 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
780 Default = ParsedTemplateArgument();
783 if (!Default.isInvalid()) {
784 // Check only that we have a template template argument. We don't want to
785 // try to check well-formedness now, because our template template parameter
786 // might have dependent types in its template parameters, which we wouldn't
787 // be able to match now.
789 // If none of the template template parameter's template arguments mention
790 // other template parameters, we could actually perform more checking here.
791 // However, it isn't worth doing.
792 TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default);
793 if (DefaultArg.getArgument().getAsTemplate().isNull()) {
794 Diag(DefaultArg.getLocation(), diag::err_template_arg_not_class_template)
795 << DefaultArg.getSourceRange();
799 // Check for unexpanded parameter packs.
800 if (DiagnoseUnexpandedParameterPack(DefaultArg.getLocation(),
801 DefaultArg.getArgument().getAsTemplate(),
802 UPPC_DefaultArgument))
805 Param->setDefaultArgument(DefaultArg, false);
811 /// ActOnTemplateParameterList - Builds a TemplateParameterList that
812 /// contains the template parameters in Params/NumParams.
813 TemplateParameterList *
814 Sema::ActOnTemplateParameterList(unsigned Depth,
815 SourceLocation ExportLoc,
816 SourceLocation TemplateLoc,
817 SourceLocation LAngleLoc,
818 Decl **Params, unsigned NumParams,
819 SourceLocation RAngleLoc) {
820 if (ExportLoc.isValid())
821 Diag(ExportLoc, diag::warn_template_export_unsupported);
823 return TemplateParameterList::Create(Context, TemplateLoc, LAngleLoc,
824 (NamedDecl**)Params, NumParams,
828 static void SetNestedNameSpecifier(TagDecl *T, const CXXScopeSpec &SS) {
830 T->setQualifierInfo(SS.getWithLocInContext(T->getASTContext()));
834 Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
835 SourceLocation KWLoc, CXXScopeSpec &SS,
836 IdentifierInfo *Name, SourceLocation NameLoc,
838 TemplateParameterList *TemplateParams,
839 AccessSpecifier AS, SourceLocation ModulePrivateLoc,
840 SourceLocation FriendLoc,
841 unsigned NumOuterTemplateParamLists,
842 TemplateParameterList** OuterTemplateParamLists) {
843 assert(TemplateParams && TemplateParams->size() > 0 &&
844 "No template parameters");
845 assert(TUK != TUK_Reference && "Can only declare or define class templates");
846 bool Invalid = false;
848 // Check that we can declare a template here.
849 if (CheckTemplateDeclScope(S, TemplateParams))
852 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
853 assert(Kind != TTK_Enum && "can't build template of enumerated type");
855 // There is no such thing as an unnamed class template.
857 Diag(KWLoc, diag::err_template_unnamed_class);
861 // Find any previous declaration with this name. For a friend with no
862 // scope explicitly specified, we only look for tag declarations (per
863 // C++11 [basic.lookup.elab]p2).
864 DeclContext *SemanticContext;
865 LookupResult Previous(*this, Name, NameLoc,
866 (SS.isEmpty() && TUK == TUK_Friend)
867 ? LookupTagName : LookupOrdinaryName,
869 if (SS.isNotEmpty() && !SS.isInvalid()) {
870 SemanticContext = computeDeclContext(SS, true);
871 if (!SemanticContext) {
872 // FIXME: Horrible, horrible hack! We can't currently represent this
873 // in the AST, and historically we have just ignored such friend
874 // class templates, so don't complain here.
875 Diag(NameLoc, TUK == TUK_Friend
876 ? diag::warn_template_qualified_friend_ignored
877 : diag::err_template_qualified_declarator_no_match)
878 << SS.getScopeRep() << SS.getRange();
879 return TUK != TUK_Friend;
882 if (RequireCompleteDeclContext(SS, SemanticContext))
885 // If we're adding a template to a dependent context, we may need to
886 // rebuilding some of the types used within the template parameter list,
887 // now that we know what the current instantiation is.
888 if (SemanticContext->isDependentContext()) {
889 ContextRAII SavedContext(*this, SemanticContext);
890 if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
892 } else if (TUK != TUK_Friend && TUK != TUK_Reference)
893 diagnoseQualifiedDeclaration(SS, SemanticContext, Name, NameLoc);
895 LookupQualifiedName(Previous, SemanticContext);
897 SemanticContext = CurContext;
898 LookupName(Previous, S);
901 if (Previous.isAmbiguous())
904 NamedDecl *PrevDecl = nullptr;
905 if (Previous.begin() != Previous.end())
906 PrevDecl = (*Previous.begin())->getUnderlyingDecl();
908 // If there is a previous declaration with the same name, check
909 // whether this is a valid redeclaration.
910 ClassTemplateDecl *PrevClassTemplate
911 = dyn_cast_or_null<ClassTemplateDecl>(PrevDecl);
913 // We may have found the injected-class-name of a class template,
914 // class template partial specialization, or class template specialization.
915 // In these cases, grab the template that is being defined or specialized.
916 if (!PrevClassTemplate && PrevDecl && isa<CXXRecordDecl>(PrevDecl) &&
917 cast<CXXRecordDecl>(PrevDecl)->isInjectedClassName()) {
918 PrevDecl = cast<CXXRecordDecl>(PrevDecl->getDeclContext());
920 = cast<CXXRecordDecl>(PrevDecl)->getDescribedClassTemplate();
921 if (!PrevClassTemplate && isa<ClassTemplateSpecializationDecl>(PrevDecl)) {
923 = cast<ClassTemplateSpecializationDecl>(PrevDecl)
924 ->getSpecializedTemplate();
928 if (TUK == TUK_Friend) {
929 // C++ [namespace.memdef]p3:
930 // [...] When looking for a prior declaration of a class or a function
931 // declared as a friend, and when the name of the friend class or
932 // function is neither a qualified name nor a template-id, scopes outside
933 // the innermost enclosing namespace scope are not considered.
935 DeclContext *OutermostContext = CurContext;
936 while (!OutermostContext->isFileContext())
937 OutermostContext = OutermostContext->getLookupParent();
940 (OutermostContext->Equals(PrevDecl->getDeclContext()) ||
941 OutermostContext->Encloses(PrevDecl->getDeclContext()))) {
942 SemanticContext = PrevDecl->getDeclContext();
944 // Declarations in outer scopes don't matter. However, the outermost
945 // context we computed is the semantic context for our new
947 PrevDecl = PrevClassTemplate = nullptr;
948 SemanticContext = OutermostContext;
950 // Check that the chosen semantic context doesn't already contain a
951 // declaration of this name as a non-tag type.
952 LookupResult Previous(*this, Name, NameLoc, LookupOrdinaryName,
954 DeclContext *LookupContext = SemanticContext;
955 while (LookupContext->isTransparentContext())
956 LookupContext = LookupContext->getLookupParent();
957 LookupQualifiedName(Previous, LookupContext);
959 if (Previous.isAmbiguous())
962 if (Previous.begin() != Previous.end())
963 PrevDecl = (*Previous.begin())->getUnderlyingDecl();
966 } else if (PrevDecl &&
967 !isDeclInScope(PrevDecl, SemanticContext, S, SS.isValid()))
968 PrevDecl = PrevClassTemplate = nullptr;
970 if (PrevClassTemplate) {
971 // Ensure that the template parameter lists are compatible. Skip this check
972 // for a friend in a dependent context: the template parameter list itself
973 // could be dependent.
974 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
975 !TemplateParameterListsAreEqual(TemplateParams,
976 PrevClassTemplate->getTemplateParameters(),
981 // C++ [temp.class]p4:
982 // In a redeclaration, partial specialization, explicit
983 // specialization or explicit instantiation of a class template,
984 // the class-key shall agree in kind with the original class
985 // template declaration (7.1.5.3).
986 RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl();
987 if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind,
988 TUK == TUK_Definition, KWLoc, *Name)) {
989 Diag(KWLoc, diag::err_use_with_wrong_tag)
991 << FixItHint::CreateReplacement(KWLoc, PrevRecordDecl->getKindName());
992 Diag(PrevRecordDecl->getLocation(), diag::note_previous_use);
993 Kind = PrevRecordDecl->getTagKind();
996 // Check for redefinition of this class template.
997 if (TUK == TUK_Definition) {
998 if (TagDecl *Def = PrevRecordDecl->getDefinition()) {
999 Diag(NameLoc, diag::err_redefinition) << Name;
1000 Diag(Def->getLocation(), diag::note_previous_definition);
1001 // FIXME: Would it make sense to try to "forget" the previous
1002 // definition, as part of error recovery?
1006 } else if (PrevDecl && PrevDecl->isTemplateParameter()) {
1007 // Maybe we will complain about the shadowed template parameter.
1008 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl);
1009 // Just pretend that we didn't see the previous declaration.
1011 } else if (PrevDecl) {
1013 // A class template shall not have the same name as any other
1014 // template, class, function, object, enumeration, enumerator,
1015 // namespace, or type in the same scope (3.3), except as specified
1017 Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
1018 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1022 // Check the template parameter list of this declaration, possibly
1023 // merging in the template parameter list from the previous class
1024 // template declaration. Skip this check for a friend in a dependent
1025 // context, because the template parameter list might be dependent.
1026 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
1027 CheckTemplateParameterList(
1029 PrevClassTemplate ? PrevClassTemplate->getTemplateParameters()
1031 (SS.isSet() && SemanticContext && SemanticContext->isRecord() &&
1032 SemanticContext->isDependentContext())
1033 ? TPC_ClassTemplateMember
1034 : TUK == TUK_Friend ? TPC_FriendClassTemplate
1035 : TPC_ClassTemplate))
1039 // If the name of the template was qualified, we must be defining the
1040 // template out-of-line.
1041 if (!SS.isInvalid() && !Invalid && !PrevClassTemplate) {
1042 Diag(NameLoc, TUK == TUK_Friend ? diag::err_friend_decl_does_not_match
1043 : diag::err_member_decl_does_not_match)
1044 << Name << SemanticContext << /*IsDefinition*/true << SS.getRange();
1049 CXXRecordDecl *NewClass =
1050 CXXRecordDecl::Create(Context, Kind, SemanticContext, KWLoc, NameLoc, Name,
1052 PrevClassTemplate->getTemplatedDecl() : nullptr,
1053 /*DelayTypeCreation=*/true);
1054 SetNestedNameSpecifier(NewClass, SS);
1055 if (NumOuterTemplateParamLists > 0)
1056 NewClass->setTemplateParameterListsInfo(Context,
1057 NumOuterTemplateParamLists,
1058 OuterTemplateParamLists);
1060 // Add alignment attributes if necessary; these attributes are checked when
1061 // the ASTContext lays out the structure.
1062 if (TUK == TUK_Definition) {
1063 AddAlignmentAttributesForRecord(NewClass);
1064 AddMsStructLayoutForRecord(NewClass);
1067 ClassTemplateDecl *NewTemplate
1068 = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc,
1069 DeclarationName(Name), TemplateParams,
1070 NewClass, PrevClassTemplate);
1071 NewClass->setDescribedClassTemplate(NewTemplate);
1073 if (ModulePrivateLoc.isValid())
1074 NewTemplate->setModulePrivate();
1076 // Build the type for the class template declaration now.
1077 QualType T = NewTemplate->getInjectedClassNameSpecialization();
1078 T = Context.getInjectedClassNameType(NewClass, T);
1079 assert(T->isDependentType() && "Class template type is not dependent?");
1082 // If we are providing an explicit specialization of a member that is a
1083 // class template, make a note of that.
1084 if (PrevClassTemplate &&
1085 PrevClassTemplate->getInstantiatedFromMemberTemplate())
1086 PrevClassTemplate->setMemberSpecialization();
1088 // Set the access specifier.
1089 if (!Invalid && TUK != TUK_Friend && NewTemplate->getDeclContext()->isRecord())
1090 SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS);
1092 // Set the lexical context of these templates
1093 NewClass->setLexicalDeclContext(CurContext);
1094 NewTemplate->setLexicalDeclContext(CurContext);
1096 if (TUK == TUK_Definition)
1097 NewClass->startDefinition();
1100 ProcessDeclAttributeList(S, NewClass, Attr);
1102 if (PrevClassTemplate)
1103 mergeDeclAttributes(NewClass, PrevClassTemplate->getTemplatedDecl());
1105 AddPushedVisibilityAttribute(NewClass);
1107 if (TUK != TUK_Friend) {
1108 // Per C++ [basic.scope.temp]p2, skip the template parameter scopes.
1110 while ((Outer->getFlags() & Scope::TemplateParamScope) != 0)
1111 Outer = Outer->getParent();
1112 PushOnScopeChains(NewTemplate, Outer);
1114 if (PrevClassTemplate && PrevClassTemplate->getAccess() != AS_none) {
1115 NewTemplate->setAccess(PrevClassTemplate->getAccess());
1116 NewClass->setAccess(PrevClassTemplate->getAccess());
1119 NewTemplate->setObjectOfFriendDecl();
1121 // Friend templates are visible in fairly strange ways.
1122 if (!CurContext->isDependentContext()) {
1123 DeclContext *DC = SemanticContext->getRedeclContext();
1124 DC->makeDeclVisibleInContext(NewTemplate);
1125 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
1126 PushOnScopeChains(NewTemplate, EnclosingScope,
1127 /* AddToContext = */ false);
1130 FriendDecl *Friend = FriendDecl::Create(
1131 Context, CurContext, NewClass->getLocation(), NewTemplate, FriendLoc);
1132 Friend->setAccess(AS_public);
1133 CurContext->addDecl(Friend);
1137 NewTemplate->setInvalidDecl();
1138 NewClass->setInvalidDecl();
1141 ActOnDocumentableDecl(NewTemplate);
1146 /// \brief Diagnose the presence of a default template argument on a
1147 /// template parameter, which is ill-formed in certain contexts.
1149 /// \returns true if the default template argument should be dropped.
1150 static bool DiagnoseDefaultTemplateArgument(Sema &S,
1151 Sema::TemplateParamListContext TPC,
1152 SourceLocation ParamLoc,
1153 SourceRange DefArgRange) {
1155 case Sema::TPC_ClassTemplate:
1156 case Sema::TPC_VarTemplate:
1157 case Sema::TPC_TypeAliasTemplate:
1160 case Sema::TPC_FunctionTemplate:
1161 case Sema::TPC_FriendFunctionTemplateDefinition:
1162 // C++ [temp.param]p9:
1163 // A default template-argument shall not be specified in a
1164 // function template declaration or a function template
1166 // If a friend function template declaration specifies a default
1167 // template-argument, that declaration shall be a definition and shall be
1168 // the only declaration of the function template in the translation unit.
1169 // (C++98/03 doesn't have this wording; see DR226).
1170 S.Diag(ParamLoc, S.getLangOpts().CPlusPlus11 ?
1171 diag::warn_cxx98_compat_template_parameter_default_in_function_template
1172 : diag::ext_template_parameter_default_in_function_template)
1176 case Sema::TPC_ClassTemplateMember:
1177 // C++0x [temp.param]p9:
1178 // A default template-argument shall not be specified in the
1179 // template-parameter-lists of the definition of a member of a
1180 // class template that appears outside of the member's class.
1181 S.Diag(ParamLoc, diag::err_template_parameter_default_template_member)
1185 case Sema::TPC_FriendClassTemplate:
1186 case Sema::TPC_FriendFunctionTemplate:
1187 // C++ [temp.param]p9:
1188 // A default template-argument shall not be specified in a
1189 // friend template declaration.
1190 S.Diag(ParamLoc, diag::err_template_parameter_default_friend_template)
1194 // FIXME: C++0x [temp.param]p9 allows default template-arguments
1195 // for friend function templates if there is only a single
1196 // declaration (and it is a definition). Strange!
1199 llvm_unreachable("Invalid TemplateParamListContext!");
1202 /// \brief Check for unexpanded parameter packs within the template parameters
1203 /// of a template template parameter, recursively.
1204 static bool DiagnoseUnexpandedParameterPacks(Sema &S,
1205 TemplateTemplateParmDecl *TTP) {
1206 // A template template parameter which is a parameter pack is also a pack
1208 if (TTP->isParameterPack())
1211 TemplateParameterList *Params = TTP->getTemplateParameters();
1212 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
1213 NamedDecl *P = Params->getParam(I);
1214 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P)) {
1215 if (!NTTP->isParameterPack() &&
1216 S.DiagnoseUnexpandedParameterPack(NTTP->getLocation(),
1217 NTTP->getTypeSourceInfo(),
1218 Sema::UPPC_NonTypeTemplateParameterType))
1224 if (TemplateTemplateParmDecl *InnerTTP
1225 = dyn_cast<TemplateTemplateParmDecl>(P))
1226 if (DiagnoseUnexpandedParameterPacks(S, InnerTTP))
1233 /// \brief Checks the validity of a template parameter list, possibly
1234 /// considering the template parameter list from a previous
1237 /// If an "old" template parameter list is provided, it must be
1238 /// equivalent (per TemplateParameterListsAreEqual) to the "new"
1239 /// template parameter list.
1241 /// \param NewParams Template parameter list for a new template
1242 /// declaration. This template parameter list will be updated with any
1243 /// default arguments that are carried through from the previous
1244 /// template parameter list.
1246 /// \param OldParams If provided, template parameter list from a
1247 /// previous declaration of the same template. Default template
1248 /// arguments will be merged from the old template parameter list to
1249 /// the new template parameter list.
1251 /// \param TPC Describes the context in which we are checking the given
1252 /// template parameter list.
1254 /// \returns true if an error occurred, false otherwise.
1255 bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
1256 TemplateParameterList *OldParams,
1257 TemplateParamListContext TPC) {
1258 bool Invalid = false;
1260 // C++ [temp.param]p10:
1261 // The set of default template-arguments available for use with a
1262 // template declaration or definition is obtained by merging the
1263 // default arguments from the definition (if in scope) and all
1264 // declarations in scope in the same way default function
1265 // arguments are (8.3.6).
1266 bool SawDefaultArgument = false;
1267 SourceLocation PreviousDefaultArgLoc;
1269 // Dummy initialization to avoid warnings.
1270 TemplateParameterList::iterator OldParam = NewParams->end();
1272 OldParam = OldParams->begin();
1274 bool RemoveDefaultArguments = false;
1275 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
1276 NewParamEnd = NewParams->end();
1277 NewParam != NewParamEnd; ++NewParam) {
1278 // Variables used to diagnose redundant default arguments
1279 bool RedundantDefaultArg = false;
1280 SourceLocation OldDefaultLoc;
1281 SourceLocation NewDefaultLoc;
1283 // Variable used to diagnose missing default arguments
1284 bool MissingDefaultArg = false;
1286 // Variable used to diagnose non-final parameter packs
1287 bool SawParameterPack = false;
1289 if (TemplateTypeParmDecl *NewTypeParm
1290 = dyn_cast<TemplateTypeParmDecl>(*NewParam)) {
1291 // Check the presence of a default argument here.
1292 if (NewTypeParm->hasDefaultArgument() &&
1293 DiagnoseDefaultTemplateArgument(*this, TPC,
1294 NewTypeParm->getLocation(),
1295 NewTypeParm->getDefaultArgumentInfo()->getTypeLoc()
1297 NewTypeParm->removeDefaultArgument();
1299 // Merge default arguments for template type parameters.
1300 TemplateTypeParmDecl *OldTypeParm
1301 = OldParams? cast<TemplateTypeParmDecl>(*OldParam) : nullptr;
1303 if (NewTypeParm->isParameterPack()) {
1304 assert(!NewTypeParm->hasDefaultArgument() &&
1305 "Parameter packs can't have a default argument!");
1306 SawParameterPack = true;
1307 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument() &&
1308 NewTypeParm->hasDefaultArgument()) {
1309 OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc();
1310 NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc();
1311 SawDefaultArgument = true;
1312 RedundantDefaultArg = true;
1313 PreviousDefaultArgLoc = NewDefaultLoc;
1314 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument()) {
1315 // Merge the default argument from the old declaration to the
1317 NewTypeParm->setDefaultArgument(OldTypeParm->getDefaultArgumentInfo(),
1319 PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc();
1320 } else if (NewTypeParm->hasDefaultArgument()) {
1321 SawDefaultArgument = true;
1322 PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc();
1323 } else if (SawDefaultArgument)
1324 MissingDefaultArg = true;
1325 } else if (NonTypeTemplateParmDecl *NewNonTypeParm
1326 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) {
1327 // Check for unexpanded parameter packs.
1328 if (!NewNonTypeParm->isParameterPack() &&
1329 DiagnoseUnexpandedParameterPack(NewNonTypeParm->getLocation(),
1330 NewNonTypeParm->getTypeSourceInfo(),
1331 UPPC_NonTypeTemplateParameterType)) {
1336 // Check the presence of a default argument here.
1337 if (NewNonTypeParm->hasDefaultArgument() &&
1338 DiagnoseDefaultTemplateArgument(*this, TPC,
1339 NewNonTypeParm->getLocation(),
1340 NewNonTypeParm->getDefaultArgument()->getSourceRange())) {
1341 NewNonTypeParm->removeDefaultArgument();
1344 // Merge default arguments for non-type template parameters
1345 NonTypeTemplateParmDecl *OldNonTypeParm
1346 = OldParams? cast<NonTypeTemplateParmDecl>(*OldParam) : nullptr;
1347 if (NewNonTypeParm->isParameterPack()) {
1348 assert(!NewNonTypeParm->hasDefaultArgument() &&
1349 "Parameter packs can't have a default argument!");
1350 if (!NewNonTypeParm->isPackExpansion())
1351 SawParameterPack = true;
1352 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument() &&
1353 NewNonTypeParm->hasDefaultArgument()) {
1354 OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc();
1355 NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc();
1356 SawDefaultArgument = true;
1357 RedundantDefaultArg = true;
1358 PreviousDefaultArgLoc = NewDefaultLoc;
1359 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument()) {
1360 // Merge the default argument from the old declaration to the
1362 // FIXME: We need to create a new kind of "default argument"
1363 // expression that points to a previous non-type template
1365 NewNonTypeParm->setDefaultArgument(
1366 OldNonTypeParm->getDefaultArgument(),
1367 /*Inherited=*/ true);
1368 PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc();
1369 } else if (NewNonTypeParm->hasDefaultArgument()) {
1370 SawDefaultArgument = true;
1371 PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc();
1372 } else if (SawDefaultArgument)
1373 MissingDefaultArg = true;
1375 TemplateTemplateParmDecl *NewTemplateParm
1376 = cast<TemplateTemplateParmDecl>(*NewParam);
1378 // Check for unexpanded parameter packs, recursively.
1379 if (::DiagnoseUnexpandedParameterPacks(*this, NewTemplateParm)) {
1384 // Check the presence of a default argument here.
1385 if (NewTemplateParm->hasDefaultArgument() &&
1386 DiagnoseDefaultTemplateArgument(*this, TPC,
1387 NewTemplateParm->getLocation(),
1388 NewTemplateParm->getDefaultArgument().getSourceRange()))
1389 NewTemplateParm->removeDefaultArgument();
1391 // Merge default arguments for template template parameters
1392 TemplateTemplateParmDecl *OldTemplateParm
1393 = OldParams? cast<TemplateTemplateParmDecl>(*OldParam) : nullptr;
1394 if (NewTemplateParm->isParameterPack()) {
1395 assert(!NewTemplateParm->hasDefaultArgument() &&
1396 "Parameter packs can't have a default argument!");
1397 if (!NewTemplateParm->isPackExpansion())
1398 SawParameterPack = true;
1399 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument() &&
1400 NewTemplateParm->hasDefaultArgument()) {
1401 OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation();
1402 NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation();
1403 SawDefaultArgument = true;
1404 RedundantDefaultArg = true;
1405 PreviousDefaultArgLoc = NewDefaultLoc;
1406 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument()) {
1407 // Merge the default argument from the old declaration to the
1409 // FIXME: We need to create a new kind of "default argument" expression
1410 // that points to a previous template template parameter.
1411 NewTemplateParm->setDefaultArgument(
1412 OldTemplateParm->getDefaultArgument(),
1413 /*Inherited=*/ true);
1414 PreviousDefaultArgLoc
1415 = OldTemplateParm->getDefaultArgument().getLocation();
1416 } else if (NewTemplateParm->hasDefaultArgument()) {
1417 SawDefaultArgument = true;
1418 PreviousDefaultArgLoc
1419 = NewTemplateParm->getDefaultArgument().getLocation();
1420 } else if (SawDefaultArgument)
1421 MissingDefaultArg = true;
1424 // C++11 [temp.param]p11:
1425 // If a template parameter of a primary class template or alias template
1426 // is a template parameter pack, it shall be the last template parameter.
1427 if (SawParameterPack && (NewParam + 1) != NewParamEnd &&
1428 (TPC == TPC_ClassTemplate || TPC == TPC_VarTemplate ||
1429 TPC == TPC_TypeAliasTemplate)) {
1430 Diag((*NewParam)->getLocation(),
1431 diag::err_template_param_pack_must_be_last_template_parameter);
1435 if (RedundantDefaultArg) {
1436 // C++ [temp.param]p12:
1437 // A template-parameter shall not be given default arguments
1438 // by two different declarations in the same scope.
1439 Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition);
1440 Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg);
1442 } else if (MissingDefaultArg && TPC != TPC_FunctionTemplate) {
1443 // C++ [temp.param]p11:
1444 // If a template-parameter of a class template has a default
1445 // template-argument, each subsequent template-parameter shall either
1446 // have a default template-argument supplied or be a template parameter
1448 Diag((*NewParam)->getLocation(),
1449 diag::err_template_param_default_arg_missing);
1450 Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg);
1452 RemoveDefaultArguments = true;
1455 // If we have an old template parameter list that we're merging
1456 // in, move on to the next parameter.
1461 // We were missing some default arguments at the end of the list, so remove
1462 // all of the default arguments.
1463 if (RemoveDefaultArguments) {
1464 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
1465 NewParamEnd = NewParams->end();
1466 NewParam != NewParamEnd; ++NewParam) {
1467 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*NewParam))
1468 TTP->removeDefaultArgument();
1469 else if (NonTypeTemplateParmDecl *NTTP
1470 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam))
1471 NTTP->removeDefaultArgument();
1473 cast<TemplateTemplateParmDecl>(*NewParam)->removeDefaultArgument();
1482 /// A class which looks for a use of a certain level of template
1484 struct DependencyChecker : RecursiveASTVisitor<DependencyChecker> {
1485 typedef RecursiveASTVisitor<DependencyChecker> super;
1489 SourceLocation MatchLoc;
1491 DependencyChecker(unsigned Depth) : Depth(Depth), Match(false) {}
1493 DependencyChecker(TemplateParameterList *Params) : Match(false) {
1494 NamedDecl *ND = Params->getParam(0);
1495 if (TemplateTypeParmDecl *PD = dyn_cast<TemplateTypeParmDecl>(ND)) {
1496 Depth = PD->getDepth();
1497 } else if (NonTypeTemplateParmDecl *PD =
1498 dyn_cast<NonTypeTemplateParmDecl>(ND)) {
1499 Depth = PD->getDepth();
1501 Depth = cast<TemplateTemplateParmDecl>(ND)->getDepth();
1505 bool Matches(unsigned ParmDepth, SourceLocation Loc = SourceLocation()) {
1506 if (ParmDepth >= Depth) {
1514 bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
1515 return !Matches(TL.getTypePtr()->getDepth(), TL.getNameLoc());
1518 bool VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
1519 return !Matches(T->getDepth());
1522 bool TraverseTemplateName(TemplateName N) {
1523 if (TemplateTemplateParmDecl *PD =
1524 dyn_cast_or_null<TemplateTemplateParmDecl>(N.getAsTemplateDecl()))
1525 if (Matches(PD->getDepth()))
1527 return super::TraverseTemplateName(N);
1530 bool VisitDeclRefExpr(DeclRefExpr *E) {
1531 if (NonTypeTemplateParmDecl *PD =
1532 dyn_cast<NonTypeTemplateParmDecl>(E->getDecl()))
1533 if (Matches(PD->getDepth(), E->getExprLoc()))
1535 return super::VisitDeclRefExpr(E);
1538 bool VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *T) {
1539 return TraverseType(T->getReplacementType());
1543 VisitSubstTemplateTypeParmPackType(const SubstTemplateTypeParmPackType *T) {
1544 return TraverseTemplateArgument(T->getArgumentPack());
1547 bool TraverseInjectedClassNameType(const InjectedClassNameType *T) {
1548 return TraverseType(T->getInjectedSpecializationType());
1553 /// Determines whether a given type depends on the given parameter
1556 DependsOnTemplateParameters(QualType T, TemplateParameterList *Params) {
1557 DependencyChecker Checker(Params);
1558 Checker.TraverseType(T);
1559 return Checker.Match;
1562 // Find the source range corresponding to the named type in the given
1563 // nested-name-specifier, if any.
1564 static SourceRange getRangeOfTypeInNestedNameSpecifier(ASTContext &Context,
1566 const CXXScopeSpec &SS) {
1567 NestedNameSpecifierLoc NNSLoc(SS.getScopeRep(), SS.location_data());
1568 while (NestedNameSpecifier *NNS = NNSLoc.getNestedNameSpecifier()) {
1569 if (const Type *CurType = NNS->getAsType()) {
1570 if (Context.hasSameUnqualifiedType(T, QualType(CurType, 0)))
1571 return NNSLoc.getTypeLoc().getSourceRange();
1575 NNSLoc = NNSLoc.getPrefix();
1578 return SourceRange();
1581 /// \brief Match the given template parameter lists to the given scope
1582 /// specifier, returning the template parameter list that applies to the
1585 /// \param DeclStartLoc the start of the declaration that has a scope
1586 /// specifier or a template parameter list.
1588 /// \param DeclLoc The location of the declaration itself.
1590 /// \param SS the scope specifier that will be matched to the given template
1591 /// parameter lists. This scope specifier precedes a qualified name that is
1594 /// \param TemplateId The template-id following the scope specifier, if there
1595 /// is one. Used to check for a missing 'template<>'.
1597 /// \param ParamLists the template parameter lists, from the outermost to the
1598 /// innermost template parameter lists.
1600 /// \param IsFriend Whether to apply the slightly different rules for
1601 /// matching template parameters to scope specifiers in friend
1604 /// \param IsExplicitSpecialization will be set true if the entity being
1605 /// declared is an explicit specialization, false otherwise.
1607 /// \returns the template parameter list, if any, that corresponds to the
1608 /// name that is preceded by the scope specifier @p SS. This template
1609 /// parameter list may have template parameters (if we're declaring a
1610 /// template) or may have no template parameters (if we're declaring a
1611 /// template specialization), or may be NULL (if what we're declaring isn't
1612 /// itself a template).
1613 TemplateParameterList *Sema::MatchTemplateParametersToScopeSpecifier(
1614 SourceLocation DeclStartLoc, SourceLocation DeclLoc, const CXXScopeSpec &SS,
1615 TemplateIdAnnotation *TemplateId,
1616 ArrayRef<TemplateParameterList *> ParamLists, bool IsFriend,
1617 bool &IsExplicitSpecialization, bool &Invalid) {
1618 IsExplicitSpecialization = false;
1621 // The sequence of nested types to which we will match up the template
1622 // parameter lists. We first build this list by starting with the type named
1623 // by the nested-name-specifier and walking out until we run out of types.
1624 SmallVector<QualType, 4> NestedTypes;
1626 if (SS.getScopeRep()) {
1627 if (CXXRecordDecl *Record
1628 = dyn_cast_or_null<CXXRecordDecl>(computeDeclContext(SS, true)))
1629 T = Context.getTypeDeclType(Record);
1631 T = QualType(SS.getScopeRep()->getAsType(), 0);
1634 // If we found an explicit specialization that prevents us from needing
1635 // 'template<>' headers, this will be set to the location of that
1636 // explicit specialization.
1637 SourceLocation ExplicitSpecLoc;
1639 while (!T.isNull()) {
1640 NestedTypes.push_back(T);
1642 // Retrieve the parent of a record type.
1643 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
1644 // If this type is an explicit specialization, we're done.
1645 if (ClassTemplateSpecializationDecl *Spec
1646 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
1647 if (!isa<ClassTemplatePartialSpecializationDecl>(Spec) &&
1648 Spec->getSpecializationKind() == TSK_ExplicitSpecialization) {
1649 ExplicitSpecLoc = Spec->getLocation();
1652 } else if (Record->getTemplateSpecializationKind()
1653 == TSK_ExplicitSpecialization) {
1654 ExplicitSpecLoc = Record->getLocation();
1658 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Record->getParent()))
1659 T = Context.getTypeDeclType(Parent);
1665 if (const TemplateSpecializationType *TST
1666 = T->getAs<TemplateSpecializationType>()) {
1667 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
1668 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Template->getDeclContext()))
1669 T = Context.getTypeDeclType(Parent);
1676 // Look one step prior in a dependent template specialization type.
1677 if (const DependentTemplateSpecializationType *DependentTST
1678 = T->getAs<DependentTemplateSpecializationType>()) {
1679 if (NestedNameSpecifier *NNS = DependentTST->getQualifier())
1680 T = QualType(NNS->getAsType(), 0);
1686 // Look one step prior in a dependent name type.
1687 if (const DependentNameType *DependentName = T->getAs<DependentNameType>()){
1688 if (NestedNameSpecifier *NNS = DependentName->getQualifier())
1689 T = QualType(NNS->getAsType(), 0);
1695 // Retrieve the parent of an enumeration type.
1696 if (const EnumType *EnumT = T->getAs<EnumType>()) {
1697 // FIXME: Forward-declared enums require a TSK_ExplicitSpecialization
1699 EnumDecl *Enum = EnumT->getDecl();
1701 // Get to the parent type.
1702 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Enum->getParent()))
1703 T = Context.getTypeDeclType(Parent);
1711 // Reverse the nested types list, since we want to traverse from the outermost
1712 // to the innermost while checking template-parameter-lists.
1713 std::reverse(NestedTypes.begin(), NestedTypes.end());
1715 // C++0x [temp.expl.spec]p17:
1716 // A member or a member template may be nested within many
1717 // enclosing class templates. In an explicit specialization for
1718 // such a member, the member declaration shall be preceded by a
1719 // template<> for each enclosing class template that is
1720 // explicitly specialized.
1721 bool SawNonEmptyTemplateParameterList = false;
1723 auto CheckExplicitSpecialization = [&](SourceRange Range, bool Recovery) {
1724 if (SawNonEmptyTemplateParameterList) {
1725 Diag(DeclLoc, diag::err_specialize_member_of_template)
1726 << !Recovery << Range;
1728 IsExplicitSpecialization = false;
1735 auto DiagnoseMissingExplicitSpecialization = [&] (SourceRange Range) {
1736 // Check that we can have an explicit specialization here.
1737 if (CheckExplicitSpecialization(Range, true))
1740 // We don't have a template header, but we should.
1741 SourceLocation ExpectedTemplateLoc;
1742 if (!ParamLists.empty())
1743 ExpectedTemplateLoc = ParamLists[0]->getTemplateLoc();
1745 ExpectedTemplateLoc = DeclStartLoc;
1747 Diag(DeclLoc, diag::err_template_spec_needs_header)
1749 << FixItHint::CreateInsertion(ExpectedTemplateLoc, "template<> ");
1753 unsigned ParamIdx = 0;
1754 for (unsigned TypeIdx = 0, NumTypes = NestedTypes.size(); TypeIdx != NumTypes;
1756 T = NestedTypes[TypeIdx];
1758 // Whether we expect a 'template<>' header.
1759 bool NeedEmptyTemplateHeader = false;
1761 // Whether we expect a template header with parameters.
1762 bool NeedNonemptyTemplateHeader = false;
1764 // For a dependent type, the set of template parameters that we
1766 TemplateParameterList *ExpectedTemplateParams = nullptr;
1768 // C++0x [temp.expl.spec]p15:
1769 // A member or a member template may be nested within many enclosing
1770 // class templates. In an explicit specialization for such a member, the
1771 // member declaration shall be preceded by a template<> for each
1772 // enclosing class template that is explicitly specialized.
1773 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
1774 if (ClassTemplatePartialSpecializationDecl *Partial
1775 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
1776 ExpectedTemplateParams = Partial->getTemplateParameters();
1777 NeedNonemptyTemplateHeader = true;
1778 } else if (Record->isDependentType()) {
1779 if (Record->getDescribedClassTemplate()) {
1780 ExpectedTemplateParams = Record->getDescribedClassTemplate()
1781 ->getTemplateParameters();
1782 NeedNonemptyTemplateHeader = true;
1784 } else if (ClassTemplateSpecializationDecl *Spec
1785 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
1786 // C++0x [temp.expl.spec]p4:
1787 // Members of an explicitly specialized class template are defined
1788 // in the same manner as members of normal classes, and not using
1789 // the template<> syntax.
1790 if (Spec->getSpecializationKind() != TSK_ExplicitSpecialization)
1791 NeedEmptyTemplateHeader = true;
1794 } else if (Record->getTemplateSpecializationKind()) {
1795 if (Record->getTemplateSpecializationKind()
1796 != TSK_ExplicitSpecialization &&
1797 TypeIdx == NumTypes - 1)
1798 IsExplicitSpecialization = true;
1802 } else if (const TemplateSpecializationType *TST
1803 = T->getAs<TemplateSpecializationType>()) {
1804 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
1805 ExpectedTemplateParams = Template->getTemplateParameters();
1806 NeedNonemptyTemplateHeader = true;
1808 } else if (T->getAs<DependentTemplateSpecializationType>()) {
1809 // FIXME: We actually could/should check the template arguments here
1810 // against the corresponding template parameter list.
1811 NeedNonemptyTemplateHeader = false;
1814 // C++ [temp.expl.spec]p16:
1815 // In an explicit specialization declaration for a member of a class
1816 // template or a member template that ap- pears in namespace scope, the
1817 // member template and some of its enclosing class templates may remain
1818 // unspecialized, except that the declaration shall not explicitly
1819 // specialize a class member template if its en- closing class templates
1820 // are not explicitly specialized as well.
1821 if (ParamIdx < ParamLists.size()) {
1822 if (ParamLists[ParamIdx]->size() == 0) {
1823 if (CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
1827 SawNonEmptyTemplateParameterList = true;
1830 if (NeedEmptyTemplateHeader) {
1831 // If we're on the last of the types, and we need a 'template<>' header
1832 // here, then it's an explicit specialization.
1833 if (TypeIdx == NumTypes - 1)
1834 IsExplicitSpecialization = true;
1836 if (ParamIdx < ParamLists.size()) {
1837 if (ParamLists[ParamIdx]->size() > 0) {
1838 // The header has template parameters when it shouldn't. Complain.
1839 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
1840 diag::err_template_param_list_matches_nontemplate)
1842 << SourceRange(ParamLists[ParamIdx]->getLAngleLoc(),
1843 ParamLists[ParamIdx]->getRAngleLoc())
1844 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
1849 // Consume this template header.
1855 if (DiagnoseMissingExplicitSpecialization(
1856 getRangeOfTypeInNestedNameSpecifier(Context, T, SS)))
1862 if (NeedNonemptyTemplateHeader) {
1863 // In friend declarations we can have template-ids which don't
1864 // depend on the corresponding template parameter lists. But
1865 // assume that empty parameter lists are supposed to match this
1867 if (IsFriend && T->isDependentType()) {
1868 if (ParamIdx < ParamLists.size() &&
1869 DependsOnTemplateParameters(T, ParamLists[ParamIdx]))
1870 ExpectedTemplateParams = nullptr;
1875 if (ParamIdx < ParamLists.size()) {
1876 // Check the template parameter list, if we can.
1877 if (ExpectedTemplateParams &&
1878 !TemplateParameterListsAreEqual(ParamLists[ParamIdx],
1879 ExpectedTemplateParams,
1880 true, TPL_TemplateMatch))
1884 CheckTemplateParameterList(ParamLists[ParamIdx], nullptr,
1885 TPC_ClassTemplateMember))
1892 Diag(DeclLoc, diag::err_template_spec_needs_template_parameters)
1894 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
1900 // If there were at least as many template-ids as there were template
1901 // parameter lists, then there are no template parameter lists remaining for
1902 // the declaration itself.
1903 if (ParamIdx >= ParamLists.size()) {
1904 if (TemplateId && !IsFriend) {
1905 // We don't have a template header for the declaration itself, but we
1907 IsExplicitSpecialization = true;
1908 DiagnoseMissingExplicitSpecialization(SourceRange(TemplateId->LAngleLoc,
1909 TemplateId->RAngleLoc));
1911 // Fabricate an empty template parameter list for the invented header.
1912 return TemplateParameterList::Create(Context, SourceLocation(),
1913 SourceLocation(), nullptr, 0,
1920 // If there were too many template parameter lists, complain about that now.
1921 if (ParamIdx < ParamLists.size() - 1) {
1922 bool HasAnyExplicitSpecHeader = false;
1923 bool AllExplicitSpecHeaders = true;
1924 for (unsigned I = ParamIdx, E = ParamLists.size() - 1; I != E; ++I) {
1925 if (ParamLists[I]->size() == 0)
1926 HasAnyExplicitSpecHeader = true;
1928 AllExplicitSpecHeaders = false;
1931 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
1932 AllExplicitSpecHeaders ? diag::warn_template_spec_extra_headers
1933 : diag::err_template_spec_extra_headers)
1934 << SourceRange(ParamLists[ParamIdx]->getTemplateLoc(),
1935 ParamLists[ParamLists.size() - 2]->getRAngleLoc());
1937 // If there was a specialization somewhere, such that 'template<>' is
1938 // not required, and there were any 'template<>' headers, note where the
1939 // specialization occurred.
1940 if (ExplicitSpecLoc.isValid() && HasAnyExplicitSpecHeader)
1941 Diag(ExplicitSpecLoc,
1942 diag::note_explicit_template_spec_does_not_need_header)
1943 << NestedTypes.back();
1945 // We have a template parameter list with no corresponding scope, which
1946 // means that the resulting template declaration can't be instantiated
1947 // properly (we'll end up with dependent nodes when we shouldn't).
1948 if (!AllExplicitSpecHeaders)
1952 // C++ [temp.expl.spec]p16:
1953 // In an explicit specialization declaration for a member of a class
1954 // template or a member template that ap- pears in namespace scope, the
1955 // member template and some of its enclosing class templates may remain
1956 // unspecialized, except that the declaration shall not explicitly
1957 // specialize a class member template if its en- closing class templates
1958 // are not explicitly specialized as well.
1959 if (ParamLists.back()->size() == 0 &&
1960 CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
1964 // Return the last template parameter list, which corresponds to the
1965 // entity being declared.
1966 return ParamLists.back();
1969 void Sema::NoteAllFoundTemplates(TemplateName Name) {
1970 if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
1971 Diag(Template->getLocation(), diag::note_template_declared_here)
1972 << (isa<FunctionTemplateDecl>(Template)
1974 : isa<ClassTemplateDecl>(Template)
1976 : isa<VarTemplateDecl>(Template)
1978 : isa<TypeAliasTemplateDecl>(Template) ? 3 : 4)
1979 << Template->getDeclName();
1983 if (OverloadedTemplateStorage *OST = Name.getAsOverloadedTemplate()) {
1984 for (OverloadedTemplateStorage::iterator I = OST->begin(),
1987 Diag((*I)->getLocation(), diag::note_template_declared_here)
1988 << 0 << (*I)->getDeclName();
1994 QualType Sema::CheckTemplateIdType(TemplateName Name,
1995 SourceLocation TemplateLoc,
1996 TemplateArgumentListInfo &TemplateArgs) {
1997 DependentTemplateName *DTN
1998 = Name.getUnderlying().getAsDependentTemplateName();
1999 if (DTN && DTN->isIdentifier())
2000 // When building a template-id where the template-name is dependent,
2001 // assume the template is a type template. Either our assumption is
2002 // correct, or the code is ill-formed and will be diagnosed when the
2003 // dependent name is substituted.
2004 return Context.getDependentTemplateSpecializationType(ETK_None,
2005 DTN->getQualifier(),
2006 DTN->getIdentifier(),
2009 TemplateDecl *Template = Name.getAsTemplateDecl();
2010 if (!Template || isa<FunctionTemplateDecl>(Template) ||
2011 isa<VarTemplateDecl>(Template)) {
2012 // We might have a substituted template template parameter pack. If so,
2013 // build a template specialization type for it.
2014 if (Name.getAsSubstTemplateTemplateParmPack())
2015 return Context.getTemplateSpecializationType(Name, TemplateArgs);
2017 Diag(TemplateLoc, diag::err_template_id_not_a_type)
2019 NoteAllFoundTemplates(Name);
2023 // Check that the template argument list is well-formed for this
2025 SmallVector<TemplateArgument, 4> Converted;
2026 if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs,
2032 bool InstantiationDependent = false;
2033 if (TypeAliasTemplateDecl *AliasTemplate =
2034 dyn_cast<TypeAliasTemplateDecl>(Template)) {
2035 // Find the canonical type for this type alias template specialization.
2036 TypeAliasDecl *Pattern = AliasTemplate->getTemplatedDecl();
2037 if (Pattern->isInvalidDecl())
2040 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
2041 Converted.data(), Converted.size());
2043 // Only substitute for the innermost template argument list.
2044 MultiLevelTemplateArgumentList TemplateArgLists;
2045 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
2046 unsigned Depth = AliasTemplate->getTemplateParameters()->getDepth();
2047 for (unsigned I = 0; I < Depth; ++I)
2048 TemplateArgLists.addOuterTemplateArguments(None);
2050 LocalInstantiationScope Scope(*this);
2051 InstantiatingTemplate Inst(*this, TemplateLoc, Template);
2052 if (Inst.isInvalid())
2055 CanonType = SubstType(Pattern->getUnderlyingType(),
2056 TemplateArgLists, AliasTemplate->getLocation(),
2057 AliasTemplate->getDeclName());
2058 if (CanonType.isNull())
2060 } else if (Name.isDependent() ||
2061 TemplateSpecializationType::anyDependentTemplateArguments(
2062 TemplateArgs, InstantiationDependent)) {
2063 // This class template specialization is a dependent
2064 // type. Therefore, its canonical type is another class template
2065 // specialization type that contains all of the converted
2066 // arguments in canonical form. This ensures that, e.g., A<T> and
2067 // A<T, T> have identical types when A is declared as:
2069 // template<typename T, typename U = T> struct A;
2070 TemplateName CanonName = Context.getCanonicalTemplateName(Name);
2071 CanonType = Context.getTemplateSpecializationType(CanonName,
2075 // FIXME: CanonType is not actually the canonical type, and unfortunately
2076 // it is a TemplateSpecializationType that we will never use again.
2077 // In the future, we need to teach getTemplateSpecializationType to only
2078 // build the canonical type and return that to us.
2079 CanonType = Context.getCanonicalType(CanonType);
2081 // This might work out to be a current instantiation, in which
2082 // case the canonical type needs to be the InjectedClassNameType.
2084 // TODO: in theory this could be a simple hashtable lookup; most
2085 // changes to CurContext don't change the set of current
2087 if (isa<ClassTemplateDecl>(Template)) {
2088 for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) {
2089 // If we get out to a namespace, we're done.
2090 if (Ctx->isFileContext()) break;
2092 // If this isn't a record, keep looking.
2093 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx);
2094 if (!Record) continue;
2096 // Look for one of the two cases with InjectedClassNameTypes
2097 // and check whether it's the same template.
2098 if (!isa<ClassTemplatePartialSpecializationDecl>(Record) &&
2099 !Record->getDescribedClassTemplate())
2102 // Fetch the injected class name type and check whether its
2103 // injected type is equal to the type we just built.
2104 QualType ICNT = Context.getTypeDeclType(Record);
2105 QualType Injected = cast<InjectedClassNameType>(ICNT)
2106 ->getInjectedSpecializationType();
2108 if (CanonType != Injected->getCanonicalTypeInternal())
2111 // If so, the canonical type of this TST is the injected
2112 // class name type of the record we just found.
2113 assert(ICNT.isCanonical());
2118 } else if (ClassTemplateDecl *ClassTemplate
2119 = dyn_cast<ClassTemplateDecl>(Template)) {
2120 // Find the class template specialization declaration that
2121 // corresponds to these arguments.
2122 void *InsertPos = nullptr;
2123 ClassTemplateSpecializationDecl *Decl
2124 = ClassTemplate->findSpecialization(Converted, InsertPos);
2126 // This is the first time we have referenced this class template
2127 // specialization. Create the canonical declaration and add it to
2128 // the set of specializations.
2129 Decl = ClassTemplateSpecializationDecl::Create(Context,
2130 ClassTemplate->getTemplatedDecl()->getTagKind(),
2131 ClassTemplate->getDeclContext(),
2132 ClassTemplate->getTemplatedDecl()->getLocStart(),
2133 ClassTemplate->getLocation(),
2136 Converted.size(), nullptr);
2137 ClassTemplate->AddSpecialization(Decl, InsertPos);
2138 if (ClassTemplate->isOutOfLine())
2139 Decl->setLexicalDeclContext(ClassTemplate->getLexicalDeclContext());
2142 // Diagnose uses of this specialization.
2143 (void)DiagnoseUseOfDecl(Decl, TemplateLoc);
2145 CanonType = Context.getTypeDeclType(Decl);
2146 assert(isa<RecordType>(CanonType) &&
2147 "type of non-dependent specialization is not a RecordType");
2150 // Build the fully-sugared type for this class template
2151 // specialization, which refers back to the class template
2152 // specialization we created or found.
2153 return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType);
2157 Sema::ActOnTemplateIdType(CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
2158 TemplateTy TemplateD, SourceLocation TemplateLoc,
2159 SourceLocation LAngleLoc,
2160 ASTTemplateArgsPtr TemplateArgsIn,
2161 SourceLocation RAngleLoc,
2162 bool IsCtorOrDtorName) {
2166 TemplateName Template = TemplateD.get();
2168 // Translate the parser's template argument list in our AST format.
2169 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
2170 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
2172 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
2174 = Context.getDependentTemplateSpecializationType(ETK_None,
2175 DTN->getQualifier(),
2176 DTN->getIdentifier(),
2178 // Build type-source information.
2180 DependentTemplateSpecializationTypeLoc SpecTL
2181 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
2182 SpecTL.setElaboratedKeywordLoc(SourceLocation());
2183 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
2184 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2185 SpecTL.setTemplateNameLoc(TemplateLoc);
2186 SpecTL.setLAngleLoc(LAngleLoc);
2187 SpecTL.setRAngleLoc(RAngleLoc);
2188 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
2189 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
2190 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
2193 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
2195 if (Result.isNull())
2198 // Build type-source information.
2200 TemplateSpecializationTypeLoc SpecTL
2201 = TLB.push<TemplateSpecializationTypeLoc>(Result);
2202 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2203 SpecTL.setTemplateNameLoc(TemplateLoc);
2204 SpecTL.setLAngleLoc(LAngleLoc);
2205 SpecTL.setRAngleLoc(RAngleLoc);
2206 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
2207 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
2209 // NOTE: avoid constructing an ElaboratedTypeLoc if this is a
2210 // constructor or destructor name (in such a case, the scope specifier
2211 // will be attached to the enclosing Decl or Expr node).
2212 if (SS.isNotEmpty() && !IsCtorOrDtorName) {
2213 // Create an elaborated-type-specifier containing the nested-name-specifier.
2214 Result = Context.getElaboratedType(ETK_None, SS.getScopeRep(), Result);
2215 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
2216 ElabTL.setElaboratedKeywordLoc(SourceLocation());
2217 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
2220 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
2223 TypeResult Sema::ActOnTagTemplateIdType(TagUseKind TUK,
2224 TypeSpecifierType TagSpec,
2225 SourceLocation TagLoc,
2227 SourceLocation TemplateKWLoc,
2228 TemplateTy TemplateD,
2229 SourceLocation TemplateLoc,
2230 SourceLocation LAngleLoc,
2231 ASTTemplateArgsPtr TemplateArgsIn,
2232 SourceLocation RAngleLoc) {
2233 TemplateName Template = TemplateD.get();
2235 // Translate the parser's template argument list in our AST format.
2236 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
2237 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
2239 // Determine the tag kind
2240 TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
2241 ElaboratedTypeKeyword Keyword
2242 = TypeWithKeyword::getKeywordForTagTypeKind(TagKind);
2244 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
2245 QualType T = Context.getDependentTemplateSpecializationType(Keyword,
2246 DTN->getQualifier(),
2247 DTN->getIdentifier(),
2250 // Build type-source information.
2252 DependentTemplateSpecializationTypeLoc SpecTL
2253 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
2254 SpecTL.setElaboratedKeywordLoc(TagLoc);
2255 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
2256 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2257 SpecTL.setTemplateNameLoc(TemplateLoc);
2258 SpecTL.setLAngleLoc(LAngleLoc);
2259 SpecTL.setRAngleLoc(RAngleLoc);
2260 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
2261 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
2262 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
2265 if (TypeAliasTemplateDecl *TAT =
2266 dyn_cast_or_null<TypeAliasTemplateDecl>(Template.getAsTemplateDecl())) {
2267 // C++0x [dcl.type.elab]p2:
2268 // If the identifier resolves to a typedef-name or the simple-template-id
2269 // resolves to an alias template specialization, the
2270 // elaborated-type-specifier is ill-formed.
2271 Diag(TemplateLoc, diag::err_tag_reference_non_tag) << 4;
2272 Diag(TAT->getLocation(), diag::note_declared_at);
2275 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
2276 if (Result.isNull())
2277 return TypeResult(true);
2279 // Check the tag kind
2280 if (const RecordType *RT = Result->getAs<RecordType>()) {
2281 RecordDecl *D = RT->getDecl();
2283 IdentifierInfo *Id = D->getIdentifier();
2284 assert(Id && "templated class must have an identifier");
2286 if (!isAcceptableTagRedeclaration(D, TagKind, TUK == TUK_Definition,
2288 Diag(TagLoc, diag::err_use_with_wrong_tag)
2290 << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName());
2291 Diag(D->getLocation(), diag::note_previous_use);
2295 // Provide source-location information for the template specialization.
2297 TemplateSpecializationTypeLoc SpecTL
2298 = TLB.push<TemplateSpecializationTypeLoc>(Result);
2299 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2300 SpecTL.setTemplateNameLoc(TemplateLoc);
2301 SpecTL.setLAngleLoc(LAngleLoc);
2302 SpecTL.setRAngleLoc(RAngleLoc);
2303 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
2304 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
2306 // Construct an elaborated type containing the nested-name-specifier (if any)
2308 Result = Context.getElaboratedType(Keyword, SS.getScopeRep(), Result);
2309 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
2310 ElabTL.setElaboratedKeywordLoc(TagLoc);
2311 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
2312 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
2315 static bool CheckTemplatePartialSpecializationArgs(
2316 Sema &S, SourceLocation NameLoc, TemplateParameterList *TemplateParams,
2317 unsigned ExplicitArgs, SmallVectorImpl<TemplateArgument> &TemplateArgs);
2319 static bool CheckTemplateSpecializationScope(Sema &S, NamedDecl *Specialized,
2320 NamedDecl *PrevDecl,
2322 bool IsPartialSpecialization);
2324 static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D);
2326 static bool isTemplateArgumentTemplateParameter(
2327 const TemplateArgument &Arg, unsigned Depth, unsigned Index) {
2328 switch (Arg.getKind()) {
2329 case TemplateArgument::Null:
2330 case TemplateArgument::NullPtr:
2331 case TemplateArgument::Integral:
2332 case TemplateArgument::Declaration:
2333 case TemplateArgument::Pack:
2334 case TemplateArgument::TemplateExpansion:
2337 case TemplateArgument::Type: {
2338 QualType Type = Arg.getAsType();
2339 const TemplateTypeParmType *TPT =
2340 Arg.getAsType()->getAs<TemplateTypeParmType>();
2341 return TPT && !Type.hasQualifiers() &&
2342 TPT->getDepth() == Depth && TPT->getIndex() == Index;
2345 case TemplateArgument::Expression: {
2346 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg.getAsExpr());
2347 if (!DRE || !DRE->getDecl())
2349 const NonTypeTemplateParmDecl *NTTP =
2350 dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl());
2351 return NTTP && NTTP->getDepth() == Depth && NTTP->getIndex() == Index;
2354 case TemplateArgument::Template:
2355 const TemplateTemplateParmDecl *TTP =
2356 dyn_cast_or_null<TemplateTemplateParmDecl>(
2357 Arg.getAsTemplateOrTemplatePattern().getAsTemplateDecl());
2358 return TTP && TTP->getDepth() == Depth && TTP->getIndex() == Index;
2360 llvm_unreachable("unexpected kind of template argument");
2363 static bool isSameAsPrimaryTemplate(TemplateParameterList *Params,
2364 ArrayRef<TemplateArgument> Args) {
2365 if (Params->size() != Args.size())
2368 unsigned Depth = Params->getDepth();
2370 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
2371 TemplateArgument Arg = Args[I];
2373 // If the parameter is a pack expansion, the argument must be a pack
2374 // whose only element is a pack expansion.
2375 if (Params->getParam(I)->isParameterPack()) {
2376 if (Arg.getKind() != TemplateArgument::Pack || Arg.pack_size() != 1 ||
2377 !Arg.pack_begin()->isPackExpansion())
2379 Arg = Arg.pack_begin()->getPackExpansionPattern();
2382 if (!isTemplateArgumentTemplateParameter(Arg, Depth, I))
2389 /// Convert the parser's template argument list representation into our form.
2390 static TemplateArgumentListInfo
2391 makeTemplateArgumentListInfo(Sema &S, TemplateIdAnnotation &TemplateId) {
2392 TemplateArgumentListInfo TemplateArgs(TemplateId.LAngleLoc,
2393 TemplateId.RAngleLoc);
2394 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId.getTemplateArgs(),
2395 TemplateId.NumArgs);
2396 S.translateTemplateArguments(TemplateArgsPtr, TemplateArgs);
2397 return TemplateArgs;
2400 DeclResult Sema::ActOnVarTemplateSpecialization(
2401 Scope *S, Declarator &D, TypeSourceInfo *DI, SourceLocation TemplateKWLoc,
2402 TemplateParameterList *TemplateParams, StorageClass SC,
2403 bool IsPartialSpecialization) {
2404 // D must be variable template id.
2405 assert(D.getName().getKind() == UnqualifiedId::IK_TemplateId &&
2406 "Variable template specialization is declared with a template it.");
2408 TemplateIdAnnotation *TemplateId = D.getName().TemplateId;
2409 TemplateArgumentListInfo TemplateArgs =
2410 makeTemplateArgumentListInfo(*this, *TemplateId);
2411 SourceLocation TemplateNameLoc = D.getIdentifierLoc();
2412 SourceLocation LAngleLoc = TemplateId->LAngleLoc;
2413 SourceLocation RAngleLoc = TemplateId->RAngleLoc;
2415 TemplateName Name = TemplateId->Template.get();
2417 // The template-id must name a variable template.
2418 VarTemplateDecl *VarTemplate =
2419 dyn_cast_or_null<VarTemplateDecl>(Name.getAsTemplateDecl());
2421 NamedDecl *FnTemplate;
2422 if (auto *OTS = Name.getAsOverloadedTemplate())
2423 FnTemplate = *OTS->begin();
2425 FnTemplate = dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl());
2427 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template_but_method)
2428 << FnTemplate->getDeclName();
2429 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template)
2430 << IsPartialSpecialization;
2433 // Check for unexpanded parameter packs in any of the template arguments.
2434 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2435 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
2436 UPPC_PartialSpecialization))
2439 // Check that the template argument list is well-formed for this
2441 SmallVector<TemplateArgument, 4> Converted;
2442 if (CheckTemplateArgumentList(VarTemplate, TemplateNameLoc, TemplateArgs,
2446 // Check that the type of this variable template specialization
2447 // matches the expected type.
2448 TypeSourceInfo *ExpectedDI;
2450 // Do substitution on the type of the declaration
2451 TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack,
2452 Converted.data(), Converted.size());
2453 InstantiatingTemplate Inst(*this, TemplateKWLoc, VarTemplate);
2454 if (Inst.isInvalid())
2456 VarDecl *Templated = VarTemplate->getTemplatedDecl();
2458 SubstType(Templated->getTypeSourceInfo(),
2459 MultiLevelTemplateArgumentList(TemplateArgList),
2460 Templated->getTypeSpecStartLoc(), Templated->getDeclName());
2465 // Find the variable template (partial) specialization declaration that
2466 // corresponds to these arguments.
2467 if (IsPartialSpecialization) {
2468 if (CheckTemplatePartialSpecializationArgs(
2469 *this, TemplateNameLoc, VarTemplate->getTemplateParameters(),
2470 TemplateArgs.size(), Converted))
2473 bool InstantiationDependent;
2474 if (!Name.isDependent() &&
2475 !TemplateSpecializationType::anyDependentTemplateArguments(
2476 TemplateArgs.getArgumentArray(), TemplateArgs.size(),
2477 InstantiationDependent)) {
2478 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
2479 << VarTemplate->getDeclName();
2480 IsPartialSpecialization = false;
2483 if (isSameAsPrimaryTemplate(VarTemplate->getTemplateParameters(),
2485 // C++ [temp.class.spec]p9b3:
2487 // -- The argument list of the specialization shall not be identical
2488 // to the implicit argument list of the primary template.
2489 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
2490 << /*variable template*/ 1
2491 << /*is definition*/(SC != SC_Extern && !CurContext->isRecord())
2492 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
2493 // FIXME: Recover from this by treating the declaration as a redeclaration
2494 // of the primary template.
2499 void *InsertPos = nullptr;
2500 VarTemplateSpecializationDecl *PrevDecl = nullptr;
2502 if (IsPartialSpecialization)
2503 // FIXME: Template parameter list matters too
2504 PrevDecl = VarTemplate->findPartialSpecialization(Converted, InsertPos);
2506 PrevDecl = VarTemplate->findSpecialization(Converted, InsertPos);
2508 VarTemplateSpecializationDecl *Specialization = nullptr;
2510 // Check whether we can declare a variable template specialization in
2511 // the current scope.
2512 if (CheckTemplateSpecializationScope(*this, VarTemplate, PrevDecl,
2514 IsPartialSpecialization))
2517 if (PrevDecl && PrevDecl->getSpecializationKind() == TSK_Undeclared) {
2518 // Since the only prior variable template specialization with these
2519 // arguments was referenced but not declared, reuse that
2520 // declaration node as our own, updating its source location and
2521 // the list of outer template parameters to reflect our new declaration.
2522 Specialization = PrevDecl;
2523 Specialization->setLocation(TemplateNameLoc);
2525 } else if (IsPartialSpecialization) {
2526 // Create a new class template partial specialization declaration node.
2527 VarTemplatePartialSpecializationDecl *PrevPartial =
2528 cast_or_null<VarTemplatePartialSpecializationDecl>(PrevDecl);
2529 VarTemplatePartialSpecializationDecl *Partial =
2530 VarTemplatePartialSpecializationDecl::Create(
2531 Context, VarTemplate->getDeclContext(), TemplateKWLoc,
2532 TemplateNameLoc, TemplateParams, VarTemplate, DI->getType(), DI, SC,
2533 Converted.data(), Converted.size(), TemplateArgs);
2536 VarTemplate->AddPartialSpecialization(Partial, InsertPos);
2537 Specialization = Partial;
2539 // If we are providing an explicit specialization of a member variable
2540 // template specialization, make a note of that.
2541 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
2542 PrevPartial->setMemberSpecialization();
2544 // Check that all of the template parameters of the variable template
2545 // partial specialization are deducible from the template
2546 // arguments. If not, this variable template partial specialization
2547 // will never be used.
2548 llvm::SmallBitVector DeducibleParams(TemplateParams->size());
2549 MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
2550 TemplateParams->getDepth(), DeducibleParams);
2552 if (!DeducibleParams.all()) {
2553 unsigned NumNonDeducible =
2554 DeducibleParams.size() - DeducibleParams.count();
2555 Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible)
2556 << /*variable template*/ 1 << (NumNonDeducible > 1)
2557 << SourceRange(TemplateNameLoc, RAngleLoc);
2558 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) {
2559 if (!DeducibleParams[I]) {
2560 NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I));
2561 if (Param->getDeclName())
2562 Diag(Param->getLocation(), diag::note_partial_spec_unused_parameter)
2563 << Param->getDeclName();
2565 Diag(Param->getLocation(), diag::note_partial_spec_unused_parameter)
2571 // Create a new class template specialization declaration node for
2572 // this explicit specialization or friend declaration.
2573 Specialization = VarTemplateSpecializationDecl::Create(
2574 Context, VarTemplate->getDeclContext(), TemplateKWLoc, TemplateNameLoc,
2575 VarTemplate, DI->getType(), DI, SC, Converted.data(), Converted.size());
2576 Specialization->setTemplateArgsInfo(TemplateArgs);
2579 VarTemplate->AddSpecialization(Specialization, InsertPos);
2582 // C++ [temp.expl.spec]p6:
2583 // If a template, a member template or the member of a class template is
2584 // explicitly specialized then that specialization shall be declared
2585 // before the first use of that specialization that would cause an implicit
2586 // instantiation to take place, in every translation unit in which such a
2587 // use occurs; no diagnostic is required.
2588 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
2590 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
2591 // Is there any previous explicit specialization declaration?
2592 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
2599 SourceRange Range(TemplateNameLoc, RAngleLoc);
2600 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
2603 Diag(PrevDecl->getPointOfInstantiation(),
2604 diag::note_instantiation_required_here)
2605 << (PrevDecl->getTemplateSpecializationKind() !=
2606 TSK_ImplicitInstantiation);
2611 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
2612 Specialization->setLexicalDeclContext(CurContext);
2614 // Add the specialization into its lexical context, so that it can
2615 // be seen when iterating through the list of declarations in that
2616 // context. However, specializations are not found by name lookup.
2617 CurContext->addDecl(Specialization);
2619 // Note that this is an explicit specialization.
2620 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
2623 // Check that this isn't a redefinition of this specialization,
2624 // merging with previous declarations.
2625 LookupResult PrevSpec(*this, GetNameForDeclarator(D), LookupOrdinaryName,
2627 PrevSpec.addDecl(PrevDecl);
2628 D.setRedeclaration(CheckVariableDeclaration(Specialization, PrevSpec));
2629 } else if (Specialization->isStaticDataMember() &&
2630 Specialization->isOutOfLine()) {
2631 Specialization->setAccess(VarTemplate->getAccess());
2634 // Link instantiations of static data members back to the template from
2635 // which they were instantiated.
2636 if (Specialization->isStaticDataMember())
2637 Specialization->setInstantiationOfStaticDataMember(
2638 VarTemplate->getTemplatedDecl(),
2639 Specialization->getSpecializationKind());
2641 return Specialization;
2645 /// \brief A partial specialization whose template arguments have matched
2646 /// a given template-id.
2647 struct PartialSpecMatchResult {
2648 VarTemplatePartialSpecializationDecl *Partial;
2649 TemplateArgumentList *Args;
2654 Sema::CheckVarTemplateId(VarTemplateDecl *Template, SourceLocation TemplateLoc,
2655 SourceLocation TemplateNameLoc,
2656 const TemplateArgumentListInfo &TemplateArgs) {
2657 assert(Template && "A variable template id without template?");
2659 // Check that the template argument list is well-formed for this template.
2660 SmallVector<TemplateArgument, 4> Converted;
2661 if (CheckTemplateArgumentList(
2662 Template, TemplateNameLoc,
2663 const_cast<TemplateArgumentListInfo &>(TemplateArgs), false,
2667 // Find the variable template specialization declaration that
2668 // corresponds to these arguments.
2669 void *InsertPos = nullptr;
2670 if (VarTemplateSpecializationDecl *Spec = Template->findSpecialization(
2671 Converted, InsertPos))
2672 // If we already have a variable template specialization, return it.
2675 // This is the first time we have referenced this variable template
2676 // specialization. Create the canonical declaration and add it to
2677 // the set of specializations, based on the closest partial specialization
2678 // that it represents. That is,
2679 VarDecl *InstantiationPattern = Template->getTemplatedDecl();
2680 TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack,
2681 Converted.data(), Converted.size());
2682 TemplateArgumentList *InstantiationArgs = &TemplateArgList;
2683 bool AmbiguousPartialSpec = false;
2684 typedef PartialSpecMatchResult MatchResult;
2685 SmallVector<MatchResult, 4> Matched;
2686 SourceLocation PointOfInstantiation = TemplateNameLoc;
2687 TemplateSpecCandidateSet FailedCandidates(PointOfInstantiation);
2689 // 1. Attempt to find the closest partial specialization that this
2690 // specializes, if any.
2691 // If any of the template arguments is dependent, then this is probably
2692 // a placeholder for an incomplete declarative context; which must be
2693 // complete by instantiation time. Thus, do not search through the partial
2694 // specializations yet.
2695 // TODO: Unify with InstantiateClassTemplateSpecialization()?
2696 // Perhaps better after unification of DeduceTemplateArguments() and
2697 // getMoreSpecializedPartialSpecialization().
2698 bool InstantiationDependent = false;
2699 if (!TemplateSpecializationType::anyDependentTemplateArguments(
2700 TemplateArgs, InstantiationDependent)) {
2702 SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
2703 Template->getPartialSpecializations(PartialSpecs);
2705 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) {
2706 VarTemplatePartialSpecializationDecl *Partial = PartialSpecs[I];
2707 TemplateDeductionInfo Info(FailedCandidates.getLocation());
2709 if (TemplateDeductionResult Result =
2710 DeduceTemplateArguments(Partial, TemplateArgList, Info)) {
2711 // Store the failed-deduction information for use in diagnostics, later.
2712 // TODO: Actually use the failed-deduction info?
2713 FailedCandidates.addCandidate()
2714 .set(Partial, MakeDeductionFailureInfo(Context, Result, Info));
2717 Matched.push_back(PartialSpecMatchResult());
2718 Matched.back().Partial = Partial;
2719 Matched.back().Args = Info.take();
2723 if (Matched.size() >= 1) {
2724 SmallVector<MatchResult, 4>::iterator Best = Matched.begin();
2725 if (Matched.size() == 1) {
2726 // -- If exactly one matching specialization is found, the
2727 // instantiation is generated from that specialization.
2728 // We don't need to do anything for this.
2730 // -- If more than one matching specialization is found, the
2731 // partial order rules (14.5.4.2) are used to determine
2732 // whether one of the specializations is more specialized
2733 // than the others. If none of the specializations is more
2734 // specialized than all of the other matching
2735 // specializations, then the use of the variable template is
2736 // ambiguous and the program is ill-formed.
2737 for (SmallVector<MatchResult, 4>::iterator P = Best + 1,
2738 PEnd = Matched.end();
2740 if (getMoreSpecializedPartialSpecialization(P->Partial, Best->Partial,
2741 PointOfInstantiation) ==
2746 // Determine if the best partial specialization is more specialized than
2748 for (SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
2749 PEnd = Matched.end();
2751 if (P != Best && getMoreSpecializedPartialSpecialization(
2752 P->Partial, Best->Partial,
2753 PointOfInstantiation) != Best->Partial) {
2754 AmbiguousPartialSpec = true;
2760 // Instantiate using the best variable template partial specialization.
2761 InstantiationPattern = Best->Partial;
2762 InstantiationArgs = Best->Args;
2764 // -- If no match is found, the instantiation is generated
2765 // from the primary template.
2766 // InstantiationPattern = Template->getTemplatedDecl();
2770 // 2. Create the canonical declaration.
2771 // Note that we do not instantiate the variable just yet, since
2772 // instantiation is handled in DoMarkVarDeclReferenced().
2773 // FIXME: LateAttrs et al.?
2774 VarTemplateSpecializationDecl *Decl = BuildVarTemplateInstantiation(
2775 Template, InstantiationPattern, *InstantiationArgs, TemplateArgs,
2776 Converted, TemplateNameLoc, InsertPos /*, LateAttrs, StartingScope*/);
2780 if (AmbiguousPartialSpec) {
2781 // Partial ordering did not produce a clear winner. Complain.
2782 Decl->setInvalidDecl();
2783 Diag(PointOfInstantiation, diag::err_partial_spec_ordering_ambiguous)
2786 // Print the matching partial specializations.
2787 for (SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
2788 PEnd = Matched.end();
2790 Diag(P->Partial->getLocation(), diag::note_partial_spec_match)
2791 << getTemplateArgumentBindingsText(
2792 P->Partial->getTemplateParameters(), *P->Args);
2796 if (VarTemplatePartialSpecializationDecl *D =
2797 dyn_cast<VarTemplatePartialSpecializationDecl>(InstantiationPattern))
2798 Decl->setInstantiationOf(D, InstantiationArgs);
2800 assert(Decl && "No variable template specialization?");
2805 Sema::CheckVarTemplateId(const CXXScopeSpec &SS,
2806 const DeclarationNameInfo &NameInfo,
2807 VarTemplateDecl *Template, SourceLocation TemplateLoc,
2808 const TemplateArgumentListInfo *TemplateArgs) {
2810 DeclResult Decl = CheckVarTemplateId(Template, TemplateLoc, NameInfo.getLoc(),
2812 if (Decl.isInvalid())
2815 VarDecl *Var = cast<VarDecl>(Decl.get());
2816 if (!Var->getTemplateSpecializationKind())
2817 Var->setTemplateSpecializationKind(TSK_ImplicitInstantiation,
2820 // Build an ordinary singleton decl ref.
2821 return BuildDeclarationNameExpr(SS, NameInfo, Var,
2822 /*FoundD=*/nullptr, TemplateArgs);
2825 ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS,
2826 SourceLocation TemplateKWLoc,
2829 const TemplateArgumentListInfo *TemplateArgs) {
2830 // FIXME: Can we do any checking at this point? I guess we could check the
2831 // template arguments that we have against the template name, if the template
2832 // name refers to a single template. That's not a terribly common case,
2834 // foo<int> could identify a single function unambiguously
2835 // This approach does NOT work, since f<int>(1);
2836 // gets resolved prior to resorting to overload resolution
2837 // i.e., template<class T> void f(double);
2838 // vs template<class T, class U> void f(U);
2840 // These should be filtered out by our callers.
2841 assert(!R.empty() && "empty lookup results when building templateid");
2842 assert(!R.isAmbiguous() && "ambiguous lookup when building templateid");
2844 // In C++1y, check variable template ids.
2845 bool InstantiationDependent;
2846 if (R.getAsSingle<VarTemplateDecl>() &&
2847 !TemplateSpecializationType::anyDependentTemplateArguments(
2848 *TemplateArgs, InstantiationDependent)) {
2849 return CheckVarTemplateId(SS, R.getLookupNameInfo(),
2850 R.getAsSingle<VarTemplateDecl>(),
2851 TemplateKWLoc, TemplateArgs);
2854 // We don't want lookup warnings at this point.
2855 R.suppressDiagnostics();
2857 UnresolvedLookupExpr *ULE
2858 = UnresolvedLookupExpr::Create(Context, R.getNamingClass(),
2859 SS.getWithLocInContext(Context),
2861 R.getLookupNameInfo(),
2862 RequiresADL, TemplateArgs,
2863 R.begin(), R.end());
2868 // We actually only call this from template instantiation.
2870 Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS,
2871 SourceLocation TemplateKWLoc,
2872 const DeclarationNameInfo &NameInfo,
2873 const TemplateArgumentListInfo *TemplateArgs) {
2875 assert(TemplateArgs || TemplateKWLoc.isValid());
2877 if (!(DC = computeDeclContext(SS, false)) ||
2878 DC->isDependentContext() ||
2879 RequireCompleteDeclContext(SS, DC))
2880 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
2882 bool MemberOfUnknownSpecialization;
2883 LookupResult R(*this, NameInfo, LookupOrdinaryName);
2884 LookupTemplateName(R, (Scope*)nullptr, SS, QualType(), /*Entering*/ false,
2885 MemberOfUnknownSpecialization);
2887 if (R.isAmbiguous())
2891 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_non_template)
2892 << NameInfo.getName() << SS.getRange();
2896 if (ClassTemplateDecl *Temp = R.getAsSingle<ClassTemplateDecl>()) {
2897 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_class_template)
2899 << NameInfo.getName().getAsString() << SS.getRange();
2900 Diag(Temp->getLocation(), diag::note_referenced_class_template);
2904 return BuildTemplateIdExpr(SS, TemplateKWLoc, R, /*ADL*/ false, TemplateArgs);
2907 /// \brief Form a dependent template name.
2909 /// This action forms a dependent template name given the template
2910 /// name and its (presumably dependent) scope specifier. For
2911 /// example, given "MetaFun::template apply", the scope specifier \p
2912 /// SS will be "MetaFun::", \p TemplateKWLoc contains the location
2913 /// of the "template" keyword, and "apply" is the \p Name.
2914 TemplateNameKind Sema::ActOnDependentTemplateName(Scope *S,
2916 SourceLocation TemplateKWLoc,
2917 UnqualifiedId &Name,
2918 ParsedType ObjectType,
2919 bool EnteringContext,
2920 TemplateTy &Result) {
2921 if (TemplateKWLoc.isValid() && S && !S->getTemplateParamParent())
2923 getLangOpts().CPlusPlus11 ?
2924 diag::warn_cxx98_compat_template_outside_of_template :
2925 diag::ext_template_outside_of_template)
2926 << FixItHint::CreateRemoval(TemplateKWLoc);
2928 DeclContext *LookupCtx = nullptr;
2930 LookupCtx = computeDeclContext(SS, EnteringContext);
2931 if (!LookupCtx && ObjectType)
2932 LookupCtx = computeDeclContext(ObjectType.get());
2934 // C++0x [temp.names]p5:
2935 // If a name prefixed by the keyword template is not the name of
2936 // a template, the program is ill-formed. [Note: the keyword
2937 // template may not be applied to non-template members of class
2938 // templates. -end note ] [ Note: as is the case with the
2939 // typename prefix, the template prefix is allowed in cases
2940 // where it is not strictly necessary; i.e., when the
2941 // nested-name-specifier or the expression on the left of the ->
2942 // or . is not dependent on a template-parameter, or the use
2943 // does not appear in the scope of a template. -end note]
2945 // Note: C++03 was more strict here, because it banned the use of
2946 // the "template" keyword prior to a template-name that was not a
2947 // dependent name. C++ DR468 relaxed this requirement (the
2948 // "template" keyword is now permitted). We follow the C++0x
2949 // rules, even in C++03 mode with a warning, retroactively applying the DR.
2950 bool MemberOfUnknownSpecialization;
2951 TemplateNameKind TNK = isTemplateName(S, SS, TemplateKWLoc.isValid(), Name,
2952 ObjectType, EnteringContext, Result,
2953 MemberOfUnknownSpecialization);
2954 if (TNK == TNK_Non_template && LookupCtx->isDependentContext() &&
2955 isa<CXXRecordDecl>(LookupCtx) &&
2956 (!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() ||
2957 cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases())) {
2958 // This is a dependent template. Handle it below.
2959 } else if (TNK == TNK_Non_template) {
2960 Diag(Name.getLocStart(),
2961 diag::err_template_kw_refers_to_non_template)
2962 << GetNameFromUnqualifiedId(Name).getName()
2963 << Name.getSourceRange()
2965 return TNK_Non_template;
2967 // We found something; return it.
2972 NestedNameSpecifier *Qualifier = SS.getScopeRep();
2974 switch (Name.getKind()) {
2975 case UnqualifiedId::IK_Identifier:
2976 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier,
2978 return TNK_Dependent_template_name;
2980 case UnqualifiedId::IK_OperatorFunctionId:
2981 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier,
2982 Name.OperatorFunctionId.Operator));
2983 return TNK_Function_template;
2985 case UnqualifiedId::IK_LiteralOperatorId:
2986 llvm_unreachable("literal operator id cannot have a dependent scope");
2992 Diag(Name.getLocStart(),
2993 diag::err_template_kw_refers_to_non_template)
2994 << GetNameFromUnqualifiedId(Name).getName()
2995 << Name.getSourceRange()
2997 return TNK_Non_template;
3000 bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param,
3001 TemplateArgumentLoc &AL,
3002 SmallVectorImpl<TemplateArgument> &Converted) {
3003 const TemplateArgument &Arg = AL.getArgument();
3005 TypeSourceInfo *TSI = nullptr;
3007 // Check template type parameter.
3008 switch(Arg.getKind()) {
3009 case TemplateArgument::Type:
3010 // C++ [temp.arg.type]p1:
3011 // A template-argument for a template-parameter which is a
3012 // type shall be a type-id.
3013 ArgType = Arg.getAsType();
3014 TSI = AL.getTypeSourceInfo();
3016 case TemplateArgument::Template: {
3017 // We have a template type parameter but the template argument
3018 // is a template without any arguments.
3019 SourceRange SR = AL.getSourceRange();
3020 TemplateName Name = Arg.getAsTemplate();
3021 Diag(SR.getBegin(), diag::err_template_missing_args)
3023 if (TemplateDecl *Decl = Name.getAsTemplateDecl())
3024 Diag(Decl->getLocation(), diag::note_template_decl_here);
3028 case TemplateArgument::Expression: {
3029 // We have a template type parameter but the template argument is an
3030 // expression; see if maybe it is missing the "typename" keyword.
3032 DeclarationNameInfo NameInfo;
3034 if (DeclRefExpr *ArgExpr = dyn_cast<DeclRefExpr>(Arg.getAsExpr())) {
3035 SS.Adopt(ArgExpr->getQualifierLoc());
3036 NameInfo = ArgExpr->getNameInfo();
3037 } else if (DependentScopeDeclRefExpr *ArgExpr =
3038 dyn_cast<DependentScopeDeclRefExpr>(Arg.getAsExpr())) {
3039 SS.Adopt(ArgExpr->getQualifierLoc());
3040 NameInfo = ArgExpr->getNameInfo();
3041 } else if (CXXDependentScopeMemberExpr *ArgExpr =
3042 dyn_cast<CXXDependentScopeMemberExpr>(Arg.getAsExpr())) {
3043 if (ArgExpr->isImplicitAccess()) {
3044 SS.Adopt(ArgExpr->getQualifierLoc());
3045 NameInfo = ArgExpr->getMemberNameInfo();
3049 if (auto *II = NameInfo.getName().getAsIdentifierInfo()) {
3050 LookupResult Result(*this, NameInfo, LookupOrdinaryName);
3051 LookupParsedName(Result, CurScope, &SS);
3053 if (Result.getAsSingle<TypeDecl>() ||
3054 Result.getResultKind() ==
3055 LookupResult::NotFoundInCurrentInstantiation) {
3056 // Suggest that the user add 'typename' before the NNS.
3057 SourceLocation Loc = AL.getSourceRange().getBegin();
3058 Diag(Loc, getLangOpts().MSVCCompat
3059 ? diag::ext_ms_template_type_arg_missing_typename
3060 : diag::err_template_arg_must_be_type_suggest)
3061 << FixItHint::CreateInsertion(Loc, "typename ");
3062 Diag(Param->getLocation(), diag::note_template_param_here);
3064 // Recover by synthesizing a type using the location information that we
3067 Context.getDependentNameType(ETK_Typename, SS.getScopeRep(), II);
3069 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(ArgType);
3070 TL.setElaboratedKeywordLoc(SourceLocation(/*synthesized*/));
3071 TL.setQualifierLoc(SS.getWithLocInContext(Context));
3072 TL.setNameLoc(NameInfo.getLoc());
3073 TSI = TLB.getTypeSourceInfo(Context, ArgType);
3075 // Overwrite our input TemplateArgumentLoc so that we can recover
3077 AL = TemplateArgumentLoc(TemplateArgument(ArgType),
3078 TemplateArgumentLocInfo(TSI));
3086 // We have a template type parameter but the template argument
3088 SourceRange SR = AL.getSourceRange();
3089 Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR;
3090 Diag(Param->getLocation(), diag::note_template_param_here);
3096 if (CheckTemplateArgument(Param, TSI))
3099 // Add the converted template type argument.
3100 ArgType = Context.getCanonicalType(ArgType);
3103 // If an explicitly-specified template argument type is a lifetime type
3104 // with no lifetime qualifier, the __strong lifetime qualifier is inferred.
3105 if (getLangOpts().ObjCAutoRefCount &&
3106 ArgType->isObjCLifetimeType() &&
3107 !ArgType.getObjCLifetime()) {
3109 Qs.setObjCLifetime(Qualifiers::OCL_Strong);
3110 ArgType = Context.getQualifiedType(ArgType, Qs);
3113 Converted.push_back(TemplateArgument(ArgType));
3117 /// \brief Substitute template arguments into the default template argument for
3118 /// the given template type parameter.
3120 /// \param SemaRef the semantic analysis object for which we are performing
3121 /// the substitution.
3123 /// \param Template the template that we are synthesizing template arguments
3126 /// \param TemplateLoc the location of the template name that started the
3127 /// template-id we are checking.
3129 /// \param RAngleLoc the location of the right angle bracket ('>') that
3130 /// terminates the template-id.
3132 /// \param Param the template template parameter whose default we are
3133 /// substituting into.
3135 /// \param Converted the list of template arguments provided for template
3136 /// parameters that precede \p Param in the template parameter list.
3137 /// \returns the substituted template argument, or NULL if an error occurred.
3138 static TypeSourceInfo *
3139 SubstDefaultTemplateArgument(Sema &SemaRef,
3140 TemplateDecl *Template,
3141 SourceLocation TemplateLoc,
3142 SourceLocation RAngleLoc,
3143 TemplateTypeParmDecl *Param,
3144 SmallVectorImpl<TemplateArgument> &Converted) {
3145 TypeSourceInfo *ArgType = Param->getDefaultArgumentInfo();
3147 // If the argument type is dependent, instantiate it now based
3148 // on the previously-computed template arguments.
3149 if (ArgType->getType()->isDependentType()) {
3150 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
3151 Template, Converted,
3152 SourceRange(TemplateLoc, RAngleLoc));
3153 if (Inst.isInvalid())
3156 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
3157 Converted.data(), Converted.size());
3159 // Only substitute for the innermost template argument list.
3160 MultiLevelTemplateArgumentList TemplateArgLists;
3161 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3162 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3163 TemplateArgLists.addOuterTemplateArguments(None);
3165 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
3167 SemaRef.SubstType(ArgType, TemplateArgLists,
3168 Param->getDefaultArgumentLoc(), Param->getDeclName());
3174 /// \brief Substitute template arguments into the default template argument for
3175 /// the given non-type template parameter.
3177 /// \param SemaRef the semantic analysis object for which we are performing
3178 /// the substitution.
3180 /// \param Template the template that we are synthesizing template arguments
3183 /// \param TemplateLoc the location of the template name that started the
3184 /// template-id we are checking.
3186 /// \param RAngleLoc the location of the right angle bracket ('>') that
3187 /// terminates the template-id.
3189 /// \param Param the non-type template parameter whose default we are
3190 /// substituting into.
3192 /// \param Converted the list of template arguments provided for template
3193 /// parameters that precede \p Param in the template parameter list.
3195 /// \returns the substituted template argument, or NULL if an error occurred.
3197 SubstDefaultTemplateArgument(Sema &SemaRef,
3198 TemplateDecl *Template,
3199 SourceLocation TemplateLoc,
3200 SourceLocation RAngleLoc,
3201 NonTypeTemplateParmDecl *Param,
3202 SmallVectorImpl<TemplateArgument> &Converted) {
3203 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
3204 Template, Converted,
3205 SourceRange(TemplateLoc, RAngleLoc));
3206 if (Inst.isInvalid())
3209 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
3210 Converted.data(), Converted.size());
3212 // Only substitute for the innermost template argument list.
3213 MultiLevelTemplateArgumentList TemplateArgLists;
3214 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3215 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3216 TemplateArgLists.addOuterTemplateArguments(None);
3218 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
3219 EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
3220 return SemaRef.SubstExpr(Param->getDefaultArgument(), TemplateArgLists);
3223 /// \brief Substitute template arguments into the default template argument for
3224 /// the given template template parameter.
3226 /// \param SemaRef the semantic analysis object for which we are performing
3227 /// the substitution.
3229 /// \param Template the template that we are synthesizing template arguments
3232 /// \param TemplateLoc the location of the template name that started the
3233 /// template-id we are checking.
3235 /// \param RAngleLoc the location of the right angle bracket ('>') that
3236 /// terminates the template-id.
3238 /// \param Param the template template parameter whose default we are
3239 /// substituting into.
3241 /// \param Converted the list of template arguments provided for template
3242 /// parameters that precede \p Param in the template parameter list.
3244 /// \param QualifierLoc Will be set to the nested-name-specifier (with
3245 /// source-location information) that precedes the template name.
3247 /// \returns the substituted template argument, or NULL if an error occurred.
3249 SubstDefaultTemplateArgument(Sema &SemaRef,
3250 TemplateDecl *Template,
3251 SourceLocation TemplateLoc,
3252 SourceLocation RAngleLoc,
3253 TemplateTemplateParmDecl *Param,
3254 SmallVectorImpl<TemplateArgument> &Converted,
3255 NestedNameSpecifierLoc &QualifierLoc) {
3256 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, Template, Converted,
3257 SourceRange(TemplateLoc, RAngleLoc));
3258 if (Inst.isInvalid())
3259 return TemplateName();
3261 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
3262 Converted.data(), Converted.size());
3264 // Only substitute for the innermost template argument list.
3265 MultiLevelTemplateArgumentList TemplateArgLists;
3266 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3267 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3268 TemplateArgLists.addOuterTemplateArguments(None);
3270 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
3271 // Substitute into the nested-name-specifier first,
3272 QualifierLoc = Param->getDefaultArgument().getTemplateQualifierLoc();
3275 SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgLists);
3277 return TemplateName();
3280 return SemaRef.SubstTemplateName(
3282 Param->getDefaultArgument().getArgument().getAsTemplate(),
3283 Param->getDefaultArgument().getTemplateNameLoc(),
3287 /// \brief If the given template parameter has a default template
3288 /// argument, substitute into that default template argument and
3289 /// return the corresponding template argument.
3291 Sema::SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template,
3292 SourceLocation TemplateLoc,
3293 SourceLocation RAngleLoc,
3295 SmallVectorImpl<TemplateArgument>
3297 bool &HasDefaultArg) {
3298 HasDefaultArg = false;
3300 if (TemplateTypeParmDecl *TypeParm = dyn_cast<TemplateTypeParmDecl>(Param)) {
3301 if (!TypeParm->hasDefaultArgument())
3302 return TemplateArgumentLoc();
3304 HasDefaultArg = true;
3305 TypeSourceInfo *DI = SubstDefaultTemplateArgument(*this, Template,
3311 return TemplateArgumentLoc(TemplateArgument(DI->getType()), DI);
3313 return TemplateArgumentLoc();
3316 if (NonTypeTemplateParmDecl *NonTypeParm
3317 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3318 if (!NonTypeParm->hasDefaultArgument())
3319 return TemplateArgumentLoc();
3321 HasDefaultArg = true;
3322 ExprResult Arg = SubstDefaultTemplateArgument(*this, Template,
3327 if (Arg.isInvalid())
3328 return TemplateArgumentLoc();
3330 Expr *ArgE = Arg.getAs<Expr>();
3331 return TemplateArgumentLoc(TemplateArgument(ArgE), ArgE);
3334 TemplateTemplateParmDecl *TempTempParm
3335 = cast<TemplateTemplateParmDecl>(Param);
3336 if (!TempTempParm->hasDefaultArgument())
3337 return TemplateArgumentLoc();
3339 HasDefaultArg = true;
3340 NestedNameSpecifierLoc QualifierLoc;
3341 TemplateName TName = SubstDefaultTemplateArgument(*this, Template,
3348 return TemplateArgumentLoc();
3350 return TemplateArgumentLoc(TemplateArgument(TName),
3351 TempTempParm->getDefaultArgument().getTemplateQualifierLoc(),
3352 TempTempParm->getDefaultArgument().getTemplateNameLoc());
3355 /// \brief Check that the given template argument corresponds to the given
3356 /// template parameter.
3358 /// \param Param The template parameter against which the argument will be
3361 /// \param Arg The template argument.
3363 /// \param Template The template in which the template argument resides.
3365 /// \param TemplateLoc The location of the template name for the template
3366 /// whose argument list we're matching.
3368 /// \param RAngleLoc The location of the right angle bracket ('>') that closes
3369 /// the template argument list.
3371 /// \param ArgumentPackIndex The index into the argument pack where this
3372 /// argument will be placed. Only valid if the parameter is a parameter pack.
3374 /// \param Converted The checked, converted argument will be added to the
3375 /// end of this small vector.
3377 /// \param CTAK Describes how we arrived at this particular template argument:
3378 /// explicitly written, deduced, etc.
3380 /// \returns true on error, false otherwise.
3381 bool Sema::CheckTemplateArgument(NamedDecl *Param,
3382 TemplateArgumentLoc &Arg,
3383 NamedDecl *Template,
3384 SourceLocation TemplateLoc,
3385 SourceLocation RAngleLoc,
3386 unsigned ArgumentPackIndex,
3387 SmallVectorImpl<TemplateArgument> &Converted,
3388 CheckTemplateArgumentKind CTAK) {
3389 // Check template type parameters.
3390 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param))
3391 return CheckTemplateTypeArgument(TTP, Arg, Converted);
3393 // Check non-type template parameters.
3394 if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3395 // Do substitution on the type of the non-type template parameter
3396 // with the template arguments we've seen thus far. But if the
3397 // template has a dependent context then we cannot substitute yet.
3398 QualType NTTPType = NTTP->getType();
3399 if (NTTP->isParameterPack() && NTTP->isExpandedParameterPack())
3400 NTTPType = NTTP->getExpansionType(ArgumentPackIndex);
3402 if (NTTPType->isDependentType() &&
3403 !isa<TemplateTemplateParmDecl>(Template) &&
3404 !Template->getDeclContext()->isDependentContext()) {
3405 // Do substitution on the type of the non-type template parameter.
3406 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
3408 SourceRange(TemplateLoc, RAngleLoc));
3409 if (Inst.isInvalid())
3412 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
3413 Converted.data(), Converted.size());
3414 NTTPType = SubstType(NTTPType,
3415 MultiLevelTemplateArgumentList(TemplateArgs),
3416 NTTP->getLocation(),
3417 NTTP->getDeclName());
3418 // If that worked, check the non-type template parameter type
3420 if (!NTTPType.isNull())
3421 NTTPType = CheckNonTypeTemplateParameterType(NTTPType,
3422 NTTP->getLocation());
3423 if (NTTPType.isNull())
3427 switch (Arg.getArgument().getKind()) {
3428 case TemplateArgument::Null:
3429 llvm_unreachable("Should never see a NULL template argument here");
3431 case TemplateArgument::Expression: {
3432 TemplateArgument Result;
3434 CheckTemplateArgument(NTTP, NTTPType, Arg.getArgument().getAsExpr(),
3436 if (Res.isInvalid())
3439 Converted.push_back(Result);
3443 case TemplateArgument::Declaration:
3444 case TemplateArgument::Integral:
3445 case TemplateArgument::NullPtr:
3446 // We've already checked this template argument, so just copy
3447 // it to the list of converted arguments.
3448 Converted.push_back(Arg.getArgument());
3451 case TemplateArgument::Template:
3452 case TemplateArgument::TemplateExpansion:
3453 // We were given a template template argument. It may not be ill-formed;
3455 if (DependentTemplateName *DTN
3456 = Arg.getArgument().getAsTemplateOrTemplatePattern()
3457 .getAsDependentTemplateName()) {
3458 // We have a template argument such as \c T::template X, which we
3459 // parsed as a template template argument. However, since we now
3460 // know that we need a non-type template argument, convert this
3461 // template name into an expression.
3463 DeclarationNameInfo NameInfo(DTN->getIdentifier(),
3464 Arg.getTemplateNameLoc());
3467 SS.Adopt(Arg.getTemplateQualifierLoc());
3468 // FIXME: the template-template arg was a DependentTemplateName,
3469 // so it was provided with a template keyword. However, its source
3470 // location is not stored in the template argument structure.
3471 SourceLocation TemplateKWLoc;
3472 ExprResult E = DependentScopeDeclRefExpr::Create(
3473 Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo,
3476 // If we parsed the template argument as a pack expansion, create a
3477 // pack expansion expression.
3478 if (Arg.getArgument().getKind() == TemplateArgument::TemplateExpansion){
3479 E = ActOnPackExpansion(E.get(), Arg.getTemplateEllipsisLoc());
3484 TemplateArgument Result;
3485 E = CheckTemplateArgument(NTTP, NTTPType, E.get(), Result);
3489 Converted.push_back(Result);
3493 // We have a template argument that actually does refer to a class
3494 // template, alias template, or template template parameter, and
3495 // therefore cannot be a non-type template argument.
3496 Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr)
3497 << Arg.getSourceRange();
3499 Diag(Param->getLocation(), diag::note_template_param_here);
3502 case TemplateArgument::Type: {
3503 // We have a non-type template parameter but the template
3504 // argument is a type.
3506 // C++ [temp.arg]p2:
3507 // In a template-argument, an ambiguity between a type-id and
3508 // an expression is resolved to a type-id, regardless of the
3509 // form of the corresponding template-parameter.
3511 // We warn specifically about this case, since it can be rather
3512 // confusing for users.
3513 QualType T = Arg.getArgument().getAsType();
3514 SourceRange SR = Arg.getSourceRange();
3515 if (T->isFunctionType())
3516 Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T;
3518 Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR;
3519 Diag(Param->getLocation(), diag::note_template_param_here);
3523 case TemplateArgument::Pack:
3524 llvm_unreachable("Caller must expand template argument packs");
3531 // Check template template parameters.
3532 TemplateTemplateParmDecl *TempParm = cast<TemplateTemplateParmDecl>(Param);
3534 // Substitute into the template parameter list of the template
3535 // template parameter, since previously-supplied template arguments
3536 // may appear within the template template parameter.
3538 // Set up a template instantiation context.
3539 LocalInstantiationScope Scope(*this);
3540 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
3541 TempParm, Converted,
3542 SourceRange(TemplateLoc, RAngleLoc));
3543 if (Inst.isInvalid())
3546 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
3547 Converted.data(), Converted.size());
3548 TempParm = cast_or_null<TemplateTemplateParmDecl>(
3549 SubstDecl(TempParm, CurContext,
3550 MultiLevelTemplateArgumentList(TemplateArgs)));
3555 switch (Arg.getArgument().getKind()) {
3556 case TemplateArgument::Null:
3557 llvm_unreachable("Should never see a NULL template argument here");
3559 case TemplateArgument::Template:
3560 case TemplateArgument::TemplateExpansion:
3561 if (CheckTemplateArgument(TempParm, Arg, ArgumentPackIndex))
3564 Converted.push_back(Arg.getArgument());
3567 case TemplateArgument::Expression:
3568 case TemplateArgument::Type:
3569 // We have a template template parameter but the template
3570 // argument does not refer to a template.
3571 Diag(Arg.getLocation(), diag::err_template_arg_must_be_template)
3572 << getLangOpts().CPlusPlus11;
3575 case TemplateArgument::Declaration:
3576 llvm_unreachable("Declaration argument with template template parameter");
3577 case TemplateArgument::Integral:
3578 llvm_unreachable("Integral argument with template template parameter");
3579 case TemplateArgument::NullPtr:
3580 llvm_unreachable("Null pointer argument with template template parameter");
3582 case TemplateArgument::Pack:
3583 llvm_unreachable("Caller must expand template argument packs");
3589 /// \brief Diagnose an arity mismatch in the
3590 static bool diagnoseArityMismatch(Sema &S, TemplateDecl *Template,
3591 SourceLocation TemplateLoc,
3592 TemplateArgumentListInfo &TemplateArgs) {
3593 TemplateParameterList *Params = Template->getTemplateParameters();
3594 unsigned NumParams = Params->size();
3595 unsigned NumArgs = TemplateArgs.size();
3598 if (NumArgs > NumParams)
3599 Range = SourceRange(TemplateArgs[NumParams].getLocation(),
3600 TemplateArgs.getRAngleLoc());
3601 S.Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
3602 << (NumArgs > NumParams)
3603 << (isa<ClassTemplateDecl>(Template)? 0 :
3604 isa<FunctionTemplateDecl>(Template)? 1 :
3605 isa<TemplateTemplateParmDecl>(Template)? 2 : 3)
3606 << Template << Range;
3607 S.Diag(Template->getLocation(), diag::note_template_decl_here)
3608 << Params->getSourceRange();
3612 /// \brief Check whether the template parameter is a pack expansion, and if so,
3613 /// determine the number of parameters produced by that expansion. For instance:
3616 /// template<typename ...Ts> struct A {
3617 /// template<Ts ...NTs, template<Ts> class ...TTs, typename ...Us> struct B;
3621 /// In \c A<int,int>::B, \c NTs and \c TTs have expanded pack size 2, and \c Us
3622 /// is not a pack expansion, so returns an empty Optional.
3623 static Optional<unsigned> getExpandedPackSize(NamedDecl *Param) {
3624 if (NonTypeTemplateParmDecl *NTTP
3625 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3626 if (NTTP->isExpandedParameterPack())
3627 return NTTP->getNumExpansionTypes();
3630 if (TemplateTemplateParmDecl *TTP
3631 = dyn_cast<TemplateTemplateParmDecl>(Param)) {
3632 if (TTP->isExpandedParameterPack())
3633 return TTP->getNumExpansionTemplateParameters();
3639 /// \brief Check that the given template argument list is well-formed
3640 /// for specializing the given template.
3641 bool Sema::CheckTemplateArgumentList(TemplateDecl *Template,
3642 SourceLocation TemplateLoc,
3643 TemplateArgumentListInfo &TemplateArgs,
3644 bool PartialTemplateArgs,
3645 SmallVectorImpl<TemplateArgument> &Converted) {
3646 TemplateParameterList *Params = Template->getTemplateParameters();
3648 SourceLocation RAngleLoc = TemplateArgs.getRAngleLoc();
3650 // C++ [temp.arg]p1:
3651 // [...] The type and form of each template-argument specified in
3652 // a template-id shall match the type and form specified for the
3653 // corresponding parameter declared by the template in its
3654 // template-parameter-list.
3655 bool isTemplateTemplateParameter = isa<TemplateTemplateParmDecl>(Template);
3656 SmallVector<TemplateArgument, 2> ArgumentPack;
3657 unsigned ArgIdx = 0, NumArgs = TemplateArgs.size();
3658 LocalInstantiationScope InstScope(*this, true);
3659 for (TemplateParameterList::iterator Param = Params->begin(),
3660 ParamEnd = Params->end();
3661 Param != ParamEnd; /* increment in loop */) {
3662 // If we have an expanded parameter pack, make sure we don't have too
3664 if (Optional<unsigned> Expansions = getExpandedPackSize(*Param)) {
3665 if (*Expansions == ArgumentPack.size()) {
3666 // We're done with this parameter pack. Pack up its arguments and add
3667 // them to the list.
3668 Converted.push_back(
3669 TemplateArgument::CreatePackCopy(Context,
3670 ArgumentPack.data(),
3671 ArgumentPack.size()));
3672 ArgumentPack.clear();
3674 // This argument is assigned to the next parameter.
3677 } else if (ArgIdx == NumArgs && !PartialTemplateArgs) {
3678 // Not enough arguments for this parameter pack.
3679 Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
3681 << (isa<ClassTemplateDecl>(Template)? 0 :
3682 isa<FunctionTemplateDecl>(Template)? 1 :
3683 isa<TemplateTemplateParmDecl>(Template)? 2 : 3)
3685 Diag(Template->getLocation(), diag::note_template_decl_here)
3686 << Params->getSourceRange();
3691 if (ArgIdx < NumArgs) {
3692 // Check the template argument we were given.
3693 if (CheckTemplateArgument(*Param, TemplateArgs[ArgIdx], Template,
3694 TemplateLoc, RAngleLoc,
3695 ArgumentPack.size(), Converted))
3698 if (TemplateArgs[ArgIdx].getArgument().isPackExpansion() &&
3699 isa<TypeAliasTemplateDecl>(Template) &&
3700 !(Param + 1 == ParamEnd && (*Param)->isTemplateParameterPack() &&
3701 !getExpandedPackSize(*Param))) {
3702 // Core issue 1430: we have a pack expansion as an argument to an
3703 // alias template, and it's not part of a final parameter pack. This
3704 // can't be canonicalized, so reject it now.
3705 Diag(TemplateArgs[ArgIdx].getLocation(),
3706 diag::err_alias_template_expansion_into_fixed_list)
3707 << TemplateArgs[ArgIdx].getSourceRange();
3708 Diag((*Param)->getLocation(), diag::note_template_param_here);
3712 // We're now done with this argument.
3715 if ((*Param)->isTemplateParameterPack()) {
3716 // The template parameter was a template parameter pack, so take the
3717 // deduced argument and place it on the argument pack. Note that we
3718 // stay on the same template parameter so that we can deduce more
3720 ArgumentPack.push_back(Converted.pop_back_val());
3722 // Move to the next template parameter.
3726 // If we just saw a pack expansion, then directly convert the remaining
3727 // arguments, because we don't know what parameters they'll match up
3729 if (TemplateArgs[ArgIdx-1].getArgument().isPackExpansion()) {
3730 bool InFinalParameterPack = Param != ParamEnd &&
3731 Param + 1 == ParamEnd &&
3732 (*Param)->isTemplateParameterPack() &&
3733 !getExpandedPackSize(*Param);
3735 if (!InFinalParameterPack && !ArgumentPack.empty()) {
3736 // If we were part way through filling in an expanded parameter pack,
3737 // fall back to just producing individual arguments.
3738 Converted.insert(Converted.end(),
3739 ArgumentPack.begin(), ArgumentPack.end());
3740 ArgumentPack.clear();
3743 while (ArgIdx < NumArgs) {
3744 if (InFinalParameterPack)
3745 ArgumentPack.push_back(TemplateArgs[ArgIdx].getArgument());
3747 Converted.push_back(TemplateArgs[ArgIdx].getArgument());
3751 // Push the argument pack onto the list of converted arguments.
3752 if (InFinalParameterPack && !ArgumentPack.empty()) {
3753 Converted.push_back(
3754 TemplateArgument::CreatePackCopy(Context,
3755 ArgumentPack.data(),
3756 ArgumentPack.size()));
3757 ArgumentPack.clear();
3766 // If we're checking a partial template argument list, we're done.
3767 if (PartialTemplateArgs) {
3768 if ((*Param)->isTemplateParameterPack() && !ArgumentPack.empty())
3769 Converted.push_back(TemplateArgument::CreatePackCopy(Context,
3770 ArgumentPack.data(),
3771 ArgumentPack.size()));
3776 // If we have a template parameter pack with no more corresponding
3777 // arguments, just break out now and we'll fill in the argument pack below.
3778 if ((*Param)->isTemplateParameterPack()) {
3779 assert(!getExpandedPackSize(*Param) &&
3780 "Should have dealt with this already");
3782 // A non-expanded parameter pack before the end of the parameter list
3783 // only occurs for an ill-formed template parameter list, unless we've
3784 // got a partial argument list for a function template, so just bail out.
3785 if (Param + 1 != ParamEnd)
3788 Converted.push_back(TemplateArgument::CreatePackCopy(Context,
3789 ArgumentPack.data(),
3790 ArgumentPack.size()));
3791 ArgumentPack.clear();
3797 // Check whether we have a default argument.
3798 TemplateArgumentLoc Arg;
3800 // Retrieve the default template argument from the template
3801 // parameter. For each kind of template parameter, we substitute the
3802 // template arguments provided thus far and any "outer" template arguments
3803 // (when the template parameter was part of a nested template) into
3804 // the default argument.
3805 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*Param)) {
3806 if (!TTP->hasDefaultArgument())
3807 return diagnoseArityMismatch(*this, Template, TemplateLoc,
3810 TypeSourceInfo *ArgType = SubstDefaultTemplateArgument(*this,
3819 Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()),
3821 } else if (NonTypeTemplateParmDecl *NTTP
3822 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) {
3823 if (!NTTP->hasDefaultArgument())
3824 return diagnoseArityMismatch(*this, Template, TemplateLoc,
3827 ExprResult E = SubstDefaultTemplateArgument(*this, Template,
3835 Expr *Ex = E.getAs<Expr>();
3836 Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex);
3838 TemplateTemplateParmDecl *TempParm
3839 = cast<TemplateTemplateParmDecl>(*Param);
3841 if (!TempParm->hasDefaultArgument())
3842 return diagnoseArityMismatch(*this, Template, TemplateLoc,
3845 NestedNameSpecifierLoc QualifierLoc;
3846 TemplateName Name = SubstDefaultTemplateArgument(*this, Template,
3855 Arg = TemplateArgumentLoc(TemplateArgument(Name), QualifierLoc,
3856 TempParm->getDefaultArgument().getTemplateNameLoc());
3859 // Introduce an instantiation record that describes where we are using
3860 // the default template argument.
3861 InstantiatingTemplate Inst(*this, RAngleLoc, Template, *Param, Converted,
3862 SourceRange(TemplateLoc, RAngleLoc));
3863 if (Inst.isInvalid())
3866 // Check the default template argument.
3867 if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc,
3868 RAngleLoc, 0, Converted))
3871 // Core issue 150 (assumed resolution): if this is a template template
3872 // parameter, keep track of the default template arguments from the
3873 // template definition.
3874 if (isTemplateTemplateParameter)
3875 TemplateArgs.addArgument(Arg);
3877 // Move to the next template parameter and argument.
3882 // If we're performing a partial argument substitution, allow any trailing
3883 // pack expansions; they might be empty. This can happen even if
3884 // PartialTemplateArgs is false (the list of arguments is complete but
3885 // still dependent).
3886 if (ArgIdx < NumArgs && CurrentInstantiationScope &&
3887 CurrentInstantiationScope->getPartiallySubstitutedPack()) {
3888 while (ArgIdx < NumArgs &&
3889 TemplateArgs[ArgIdx].getArgument().isPackExpansion())
3890 Converted.push_back(TemplateArgs[ArgIdx++].getArgument());
3893 // If we have any leftover arguments, then there were too many arguments.
3894 // Complain and fail.
3895 if (ArgIdx < NumArgs)
3896 return diagnoseArityMismatch(*this, Template, TemplateLoc, TemplateArgs);
3902 class UnnamedLocalNoLinkageFinder
3903 : public TypeVisitor<UnnamedLocalNoLinkageFinder, bool>
3908 typedef TypeVisitor<UnnamedLocalNoLinkageFinder, bool> inherited;
3911 UnnamedLocalNoLinkageFinder(Sema &S, SourceRange SR) : S(S), SR(SR) { }
3913 bool Visit(QualType T) {
3914 return inherited::Visit(T.getTypePtr());
3917 #define TYPE(Class, Parent) \
3918 bool Visit##Class##Type(const Class##Type *);
3919 #define ABSTRACT_TYPE(Class, Parent) \
3920 bool Visit##Class##Type(const Class##Type *) { return false; }
3921 #define NON_CANONICAL_TYPE(Class, Parent) \
3922 bool Visit##Class##Type(const Class##Type *) { return false; }
3923 #include "clang/AST/TypeNodes.def"
3925 bool VisitTagDecl(const TagDecl *Tag);
3926 bool VisitNestedNameSpecifier(NestedNameSpecifier *NNS);
3930 bool UnnamedLocalNoLinkageFinder::VisitBuiltinType(const BuiltinType*) {
3934 bool UnnamedLocalNoLinkageFinder::VisitComplexType(const ComplexType* T) {
3935 return Visit(T->getElementType());
3938 bool UnnamedLocalNoLinkageFinder::VisitPointerType(const PointerType* T) {
3939 return Visit(T->getPointeeType());
3942 bool UnnamedLocalNoLinkageFinder::VisitBlockPointerType(
3943 const BlockPointerType* T) {
3944 return Visit(T->getPointeeType());
3947 bool UnnamedLocalNoLinkageFinder::VisitLValueReferenceType(
3948 const LValueReferenceType* T) {
3949 return Visit(T->getPointeeType());
3952 bool UnnamedLocalNoLinkageFinder::VisitRValueReferenceType(
3953 const RValueReferenceType* T) {
3954 return Visit(T->getPointeeType());
3957 bool UnnamedLocalNoLinkageFinder::VisitMemberPointerType(
3958 const MemberPointerType* T) {
3959 return Visit(T->getPointeeType()) || Visit(QualType(T->getClass(), 0));
3962 bool UnnamedLocalNoLinkageFinder::VisitConstantArrayType(
3963 const ConstantArrayType* T) {
3964 return Visit(T->getElementType());
3967 bool UnnamedLocalNoLinkageFinder::VisitIncompleteArrayType(
3968 const IncompleteArrayType* T) {
3969 return Visit(T->getElementType());
3972 bool UnnamedLocalNoLinkageFinder::VisitVariableArrayType(
3973 const VariableArrayType* T) {
3974 return Visit(T->getElementType());
3977 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedArrayType(
3978 const DependentSizedArrayType* T) {
3979 return Visit(T->getElementType());
3982 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedExtVectorType(
3983 const DependentSizedExtVectorType* T) {
3984 return Visit(T->getElementType());
3987 bool UnnamedLocalNoLinkageFinder::VisitVectorType(const VectorType* T) {
3988 return Visit(T->getElementType());
3991 bool UnnamedLocalNoLinkageFinder::VisitExtVectorType(const ExtVectorType* T) {
3992 return Visit(T->getElementType());
3995 bool UnnamedLocalNoLinkageFinder::VisitFunctionProtoType(
3996 const FunctionProtoType* T) {
3997 for (const auto &A : T->param_types()) {
4002 return Visit(T->getReturnType());
4005 bool UnnamedLocalNoLinkageFinder::VisitFunctionNoProtoType(
4006 const FunctionNoProtoType* T) {
4007 return Visit(T->getReturnType());
4010 bool UnnamedLocalNoLinkageFinder::VisitUnresolvedUsingType(
4011 const UnresolvedUsingType*) {
4015 bool UnnamedLocalNoLinkageFinder::VisitTypeOfExprType(const TypeOfExprType*) {
4019 bool UnnamedLocalNoLinkageFinder::VisitTypeOfType(const TypeOfType* T) {
4020 return Visit(T->getUnderlyingType());
4023 bool UnnamedLocalNoLinkageFinder::VisitDecltypeType(const DecltypeType*) {
4027 bool UnnamedLocalNoLinkageFinder::VisitUnaryTransformType(
4028 const UnaryTransformType*) {
4032 bool UnnamedLocalNoLinkageFinder::VisitAutoType(const AutoType *T) {
4033 return Visit(T->getDeducedType());
4036 bool UnnamedLocalNoLinkageFinder::VisitRecordType(const RecordType* T) {
4037 return VisitTagDecl(T->getDecl());
4040 bool UnnamedLocalNoLinkageFinder::VisitEnumType(const EnumType* T) {
4041 return VisitTagDecl(T->getDecl());
4044 bool UnnamedLocalNoLinkageFinder::VisitTemplateTypeParmType(
4045 const TemplateTypeParmType*) {
4049 bool UnnamedLocalNoLinkageFinder::VisitSubstTemplateTypeParmPackType(
4050 const SubstTemplateTypeParmPackType *) {
4054 bool UnnamedLocalNoLinkageFinder::VisitTemplateSpecializationType(
4055 const TemplateSpecializationType*) {
4059 bool UnnamedLocalNoLinkageFinder::VisitInjectedClassNameType(
4060 const InjectedClassNameType* T) {
4061 return VisitTagDecl(T->getDecl());
4064 bool UnnamedLocalNoLinkageFinder::VisitDependentNameType(
4065 const DependentNameType* T) {
4066 return VisitNestedNameSpecifier(T->getQualifier());
4069 bool UnnamedLocalNoLinkageFinder::VisitDependentTemplateSpecializationType(
4070 const DependentTemplateSpecializationType* T) {
4071 return VisitNestedNameSpecifier(T->getQualifier());
4074 bool UnnamedLocalNoLinkageFinder::VisitPackExpansionType(
4075 const PackExpansionType* T) {
4076 return Visit(T->getPattern());
4079 bool UnnamedLocalNoLinkageFinder::VisitObjCObjectType(const ObjCObjectType *) {
4083 bool UnnamedLocalNoLinkageFinder::VisitObjCInterfaceType(
4084 const ObjCInterfaceType *) {
4088 bool UnnamedLocalNoLinkageFinder::VisitObjCObjectPointerType(
4089 const ObjCObjectPointerType *) {
4093 bool UnnamedLocalNoLinkageFinder::VisitAtomicType(const AtomicType* T) {
4094 return Visit(T->getValueType());
4097 bool UnnamedLocalNoLinkageFinder::VisitTagDecl(const TagDecl *Tag) {
4098 if (Tag->getDeclContext()->isFunctionOrMethod()) {
4099 S.Diag(SR.getBegin(),
4100 S.getLangOpts().CPlusPlus11 ?
4101 diag::warn_cxx98_compat_template_arg_local_type :
4102 diag::ext_template_arg_local_type)
4103 << S.Context.getTypeDeclType(Tag) << SR;
4107 if (!Tag->hasNameForLinkage()) {
4108 S.Diag(SR.getBegin(),
4109 S.getLangOpts().CPlusPlus11 ?
4110 diag::warn_cxx98_compat_template_arg_unnamed_type :
4111 diag::ext_template_arg_unnamed_type) << SR;
4112 S.Diag(Tag->getLocation(), diag::note_template_unnamed_type_here);
4119 bool UnnamedLocalNoLinkageFinder::VisitNestedNameSpecifier(
4120 NestedNameSpecifier *NNS) {
4121 if (NNS->getPrefix() && VisitNestedNameSpecifier(NNS->getPrefix()))
4124 switch (NNS->getKind()) {
4125 case NestedNameSpecifier::Identifier:
4126 case NestedNameSpecifier::Namespace:
4127 case NestedNameSpecifier::NamespaceAlias:
4128 case NestedNameSpecifier::Global:
4129 case NestedNameSpecifier::Super:
4132 case NestedNameSpecifier::TypeSpec:
4133 case NestedNameSpecifier::TypeSpecWithTemplate:
4134 return Visit(QualType(NNS->getAsType(), 0));
4136 llvm_unreachable("Invalid NestedNameSpecifier::Kind!");
4140 /// \brief Check a template argument against its corresponding
4141 /// template type parameter.
4143 /// This routine implements the semantics of C++ [temp.arg.type]. It
4144 /// returns true if an error occurred, and false otherwise.
4145 bool Sema::CheckTemplateArgument(TemplateTypeParmDecl *Param,
4146 TypeSourceInfo *ArgInfo) {
4147 assert(ArgInfo && "invalid TypeSourceInfo");
4148 QualType Arg = ArgInfo->getType();
4149 SourceRange SR = ArgInfo->getTypeLoc().getSourceRange();
4151 if (Arg->isVariablyModifiedType()) {
4152 return Diag(SR.getBegin(), diag::err_variably_modified_template_arg) << Arg;
4153 } else if (Context.hasSameUnqualifiedType(Arg, Context.OverloadTy)) {
4154 return Diag(SR.getBegin(), diag::err_template_arg_overload_type) << SR;
4157 // C++03 [temp.arg.type]p2:
4158 // A local type, a type with no linkage, an unnamed type or a type
4159 // compounded from any of these types shall not be used as a
4160 // template-argument for a template type-parameter.
4162 // C++11 allows these, and even in C++03 we allow them as an extension with
4165 if (LangOpts.CPlusPlus11)
4167 !Diags.isIgnored(diag::warn_cxx98_compat_template_arg_unnamed_type,
4169 !Diags.isIgnored(diag::warn_cxx98_compat_template_arg_local_type,
4172 NeedsCheck = Arg->hasUnnamedOrLocalType();
4175 UnnamedLocalNoLinkageFinder Finder(*this, SR);
4176 (void)Finder.Visit(Context.getCanonicalType(Arg));
4182 enum NullPointerValueKind {
4188 /// \brief Determine whether the given template argument is a null pointer
4189 /// value of the appropriate type.
4190 static NullPointerValueKind
4191 isNullPointerValueTemplateArgument(Sema &S, NonTypeTemplateParmDecl *Param,
4192 QualType ParamType, Expr *Arg) {
4193 if (Arg->isValueDependent() || Arg->isTypeDependent())
4194 return NPV_NotNullPointer;
4196 if (!S.getLangOpts().CPlusPlus11)
4197 return NPV_NotNullPointer;
4199 // Determine whether we have a constant expression.
4200 ExprResult ArgRV = S.DefaultFunctionArrayConversion(Arg);
4201 if (ArgRV.isInvalid())
4205 Expr::EvalResult EvalResult;
4206 SmallVector<PartialDiagnosticAt, 8> Notes;
4207 EvalResult.Diag = &Notes;
4208 if (!Arg->EvaluateAsRValue(EvalResult, S.Context) ||
4209 EvalResult.HasSideEffects) {
4210 SourceLocation DiagLoc = Arg->getExprLoc();
4212 // If our only note is the usual "invalid subexpression" note, just point
4213 // the caret at its location rather than producing an essentially
4215 if (Notes.size() == 1 && Notes[0].second.getDiagID() ==
4216 diag::note_invalid_subexpr_in_const_expr) {
4217 DiagLoc = Notes[0].first;
4221 S.Diag(DiagLoc, diag::err_template_arg_not_address_constant)
4222 << Arg->getType() << Arg->getSourceRange();
4223 for (unsigned I = 0, N = Notes.size(); I != N; ++I)
4224 S.Diag(Notes[I].first, Notes[I].second);
4226 S.Diag(Param->getLocation(), diag::note_template_param_here);
4230 // C++11 [temp.arg.nontype]p1:
4231 // - an address constant expression of type std::nullptr_t
4232 if (Arg->getType()->isNullPtrType())
4233 return NPV_NullPointer;
4235 // - a constant expression that evaluates to a null pointer value (4.10); or
4236 // - a constant expression that evaluates to a null member pointer value
4238 if ((EvalResult.Val.isLValue() && !EvalResult.Val.getLValueBase()) ||
4239 (EvalResult.Val.isMemberPointer() &&
4240 !EvalResult.Val.getMemberPointerDecl())) {
4241 // If our expression has an appropriate type, we've succeeded.
4242 bool ObjCLifetimeConversion;
4243 if (S.Context.hasSameUnqualifiedType(Arg->getType(), ParamType) ||
4244 S.IsQualificationConversion(Arg->getType(), ParamType, false,
4245 ObjCLifetimeConversion))
4246 return NPV_NullPointer;
4248 // The types didn't match, but we know we got a null pointer; complain,
4249 // then recover as if the types were correct.
4250 S.Diag(Arg->getExprLoc(), diag::err_template_arg_wrongtype_null_constant)
4251 << Arg->getType() << ParamType << Arg->getSourceRange();
4252 S.Diag(Param->getLocation(), diag::note_template_param_here);
4253 return NPV_NullPointer;
4256 // If we don't have a null pointer value, but we do have a NULL pointer
4257 // constant, suggest a cast to the appropriate type.
4258 if (Arg->isNullPointerConstant(S.Context, Expr::NPC_NeverValueDependent)) {
4259 std::string Code = "static_cast<" + ParamType.getAsString() + ">(";
4260 S.Diag(Arg->getExprLoc(), diag::err_template_arg_untyped_null_constant)
4261 << ParamType << FixItHint::CreateInsertion(Arg->getLocStart(), Code)
4262 << FixItHint::CreateInsertion(S.getLocForEndOfToken(Arg->getLocEnd()),
4264 S.Diag(Param->getLocation(), diag::note_template_param_here);
4265 return NPV_NullPointer;
4268 // FIXME: If we ever want to support general, address-constant expressions
4269 // as non-type template arguments, we should return the ExprResult here to
4270 // be interpreted by the caller.
4271 return NPV_NotNullPointer;
4274 /// \brief Checks whether the given template argument is compatible with its
4275 /// template parameter.
4276 static bool CheckTemplateArgumentIsCompatibleWithParameter(
4277 Sema &S, NonTypeTemplateParmDecl *Param, QualType ParamType, Expr *ArgIn,
4278 Expr *Arg, QualType ArgType) {
4279 bool ObjCLifetimeConversion;
4280 if (ParamType->isPointerType() &&
4281 !ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType() &&
4282 S.IsQualificationConversion(ArgType, ParamType, false,
4283 ObjCLifetimeConversion)) {
4284 // For pointer-to-object types, qualification conversions are
4287 if (const ReferenceType *ParamRef = ParamType->getAs<ReferenceType>()) {
4288 if (!ParamRef->getPointeeType()->isFunctionType()) {
4289 // C++ [temp.arg.nontype]p5b3:
4290 // For a non-type template-parameter of type reference to
4291 // object, no conversions apply. The type referred to by the
4292 // reference may be more cv-qualified than the (otherwise
4293 // identical) type of the template- argument. The
4294 // template-parameter is bound directly to the
4295 // template-argument, which shall be an lvalue.
4297 // FIXME: Other qualifiers?
4298 unsigned ParamQuals = ParamRef->getPointeeType().getCVRQualifiers();
4299 unsigned ArgQuals = ArgType.getCVRQualifiers();
4301 if ((ParamQuals | ArgQuals) != ParamQuals) {
4302 S.Diag(Arg->getLocStart(),
4303 diag::err_template_arg_ref_bind_ignores_quals)
4304 << ParamType << Arg->getType() << Arg->getSourceRange();
4305 S.Diag(Param->getLocation(), diag::note_template_param_here);
4311 // At this point, the template argument refers to an object or
4312 // function with external linkage. We now need to check whether the
4313 // argument and parameter types are compatible.
4314 if (!S.Context.hasSameUnqualifiedType(ArgType,
4315 ParamType.getNonReferenceType())) {
4316 // We can't perform this conversion or binding.
4317 if (ParamType->isReferenceType())
4318 S.Diag(Arg->getLocStart(), diag::err_template_arg_no_ref_bind)
4319 << ParamType << ArgIn->getType() << Arg->getSourceRange();
4321 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible)
4322 << ArgIn->getType() << ParamType << Arg->getSourceRange();
4323 S.Diag(Param->getLocation(), diag::note_template_param_here);
4331 /// \brief Checks whether the given template argument is the address
4332 /// of an object or function according to C++ [temp.arg.nontype]p1.
4334 CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S,
4335 NonTypeTemplateParmDecl *Param,
4338 TemplateArgument &Converted) {
4339 bool Invalid = false;
4341 QualType ArgType = Arg->getType();
4343 bool AddressTaken = false;
4344 SourceLocation AddrOpLoc;
4345 if (S.getLangOpts().MicrosoftExt) {
4346 // Microsoft Visual C++ strips all casts, allows an arbitrary number of
4347 // dereference and address-of operators.
4348 Arg = Arg->IgnoreParenCasts();
4350 bool ExtWarnMSTemplateArg = false;
4351 UnaryOperatorKind FirstOpKind;
4352 SourceLocation FirstOpLoc;
4353 while (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
4354 UnaryOperatorKind UnOpKind = UnOp->getOpcode();
4355 if (UnOpKind == UO_Deref)
4356 ExtWarnMSTemplateArg = true;
4357 if (UnOpKind == UO_AddrOf || UnOpKind == UO_Deref) {
4358 Arg = UnOp->getSubExpr()->IgnoreParenCasts();
4359 if (!AddrOpLoc.isValid()) {
4360 FirstOpKind = UnOpKind;
4361 FirstOpLoc = UnOp->getOperatorLoc();
4366 if (FirstOpLoc.isValid()) {
4367 if (ExtWarnMSTemplateArg)
4368 S.Diag(ArgIn->getLocStart(), diag::ext_ms_deref_template_argument)
4369 << ArgIn->getSourceRange();
4371 if (FirstOpKind == UO_AddrOf)
4372 AddressTaken = true;
4373 else if (Arg->getType()->isPointerType()) {
4374 // We cannot let pointers get dereferenced here, that is obviously not a
4375 // constant expression.
4376 assert(FirstOpKind == UO_Deref);
4377 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
4378 << Arg->getSourceRange();
4382 // See through any implicit casts we added to fix the type.
4383 Arg = Arg->IgnoreImpCasts();
4385 // C++ [temp.arg.nontype]p1:
4387 // A template-argument for a non-type, non-template
4388 // template-parameter shall be one of: [...]
4390 // -- the address of an object or function with external
4391 // linkage, including function templates and function
4392 // template-ids but excluding non-static class members,
4393 // expressed as & id-expression where the & is optional if
4394 // the name refers to a function or array, or if the
4395 // corresponding template-parameter is a reference; or
4397 // In C++98/03 mode, give an extension warning on any extra parentheses.
4398 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
4399 bool ExtraParens = false;
4400 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) {
4401 if (!Invalid && !ExtraParens) {
4402 S.Diag(Arg->getLocStart(),
4403 S.getLangOpts().CPlusPlus11
4404 ? diag::warn_cxx98_compat_template_arg_extra_parens
4405 : diag::ext_template_arg_extra_parens)
4406 << Arg->getSourceRange();
4410 Arg = Parens->getSubExpr();
4413 while (SubstNonTypeTemplateParmExpr *subst =
4414 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
4415 Arg = subst->getReplacement()->IgnoreImpCasts();
4417 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
4418 if (UnOp->getOpcode() == UO_AddrOf) {
4419 Arg = UnOp->getSubExpr();
4420 AddressTaken = true;
4421 AddrOpLoc = UnOp->getOperatorLoc();
4425 while (SubstNonTypeTemplateParmExpr *subst =
4426 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
4427 Arg = subst->getReplacement()->IgnoreImpCasts();
4430 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg);
4431 ValueDecl *Entity = DRE ? DRE->getDecl() : nullptr;
4433 // If our parameter has pointer type, check for a null template value.
4434 if (ParamType->isPointerType() || ParamType->isNullPtrType()) {
4435 NullPointerValueKind NPV;
4436 // dllimport'd entities aren't constant but are available inside of template
4438 if (Entity && Entity->hasAttr<DLLImportAttr>())
4439 NPV = NPV_NotNullPointer;
4441 NPV = isNullPointerValueTemplateArgument(S, Param, ParamType, ArgIn);
4443 case NPV_NullPointer:
4444 S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
4445 Converted = TemplateArgument(S.Context.getCanonicalType(ParamType),
4446 /*isNullPtr=*/true);
4452 case NPV_NotNullPointer:
4457 // Stop checking the precise nature of the argument if it is value dependent,
4458 // it should be checked when instantiated.
4459 if (Arg->isValueDependent()) {
4460 Converted = TemplateArgument(ArgIn);
4464 if (isa<CXXUuidofExpr>(Arg)) {
4465 if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType,
4466 ArgIn, Arg, ArgType))
4469 Converted = TemplateArgument(ArgIn);
4474 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
4475 << Arg->getSourceRange();
4476 S.Diag(Param->getLocation(), diag::note_template_param_here);
4480 // Cannot refer to non-static data members
4481 if (isa<FieldDecl>(Entity) || isa<IndirectFieldDecl>(Entity)) {
4482 S.Diag(Arg->getLocStart(), diag::err_template_arg_field)
4483 << Entity << Arg->getSourceRange();
4484 S.Diag(Param->getLocation(), diag::note_template_param_here);
4488 // Cannot refer to non-static member functions
4489 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Entity)) {
4490 if (!Method->isStatic()) {
4491 S.Diag(Arg->getLocStart(), diag::err_template_arg_method)
4492 << Method << Arg->getSourceRange();
4493 S.Diag(Param->getLocation(), diag::note_template_param_here);
4498 FunctionDecl *Func = dyn_cast<FunctionDecl>(Entity);
4499 VarDecl *Var = dyn_cast<VarDecl>(Entity);
4501 // A non-type template argument must refer to an object or function.
4502 if (!Func && !Var) {
4503 // We found something, but we don't know specifically what it is.
4504 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_object_or_func)
4505 << Arg->getSourceRange();
4506 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here);
4510 // Address / reference template args must have external linkage in C++98.
4511 if (Entity->getFormalLinkage() == InternalLinkage) {
4512 S.Diag(Arg->getLocStart(), S.getLangOpts().CPlusPlus11 ?
4513 diag::warn_cxx98_compat_template_arg_object_internal :
4514 diag::ext_template_arg_object_internal)
4515 << !Func << Entity << Arg->getSourceRange();
4516 S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
4518 } else if (!Entity->hasLinkage()) {
4519 S.Diag(Arg->getLocStart(), diag::err_template_arg_object_no_linkage)
4520 << !Func << Entity << Arg->getSourceRange();
4521 S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
4527 // If the template parameter has pointer type, the function decays.
4528 if (ParamType->isPointerType() && !AddressTaken)
4529 ArgType = S.Context.getPointerType(Func->getType());
4530 else if (AddressTaken && ParamType->isReferenceType()) {
4531 // If we originally had an address-of operator, but the
4532 // parameter has reference type, complain and (if things look
4533 // like they will work) drop the address-of operator.
4534 if (!S.Context.hasSameUnqualifiedType(Func->getType(),
4535 ParamType.getNonReferenceType())) {
4536 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4538 S.Diag(Param->getLocation(), diag::note_template_param_here);
4542 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4544 << FixItHint::CreateRemoval(AddrOpLoc);
4545 S.Diag(Param->getLocation(), diag::note_template_param_here);
4547 ArgType = Func->getType();
4550 // A value of reference type is not an object.
4551 if (Var->getType()->isReferenceType()) {
4552 S.Diag(Arg->getLocStart(),
4553 diag::err_template_arg_reference_var)
4554 << Var->getType() << Arg->getSourceRange();
4555 S.Diag(Param->getLocation(), diag::note_template_param_here);
4559 // A template argument must have static storage duration.
4560 if (Var->getTLSKind()) {
4561 S.Diag(Arg->getLocStart(), diag::err_template_arg_thread_local)
4562 << Arg->getSourceRange();
4563 S.Diag(Var->getLocation(), diag::note_template_arg_refers_here);
4567 // If the template parameter has pointer type, we must have taken
4568 // the address of this object.
4569 if (ParamType->isReferenceType()) {
4571 // If we originally had an address-of operator, but the
4572 // parameter has reference type, complain and (if things look
4573 // like they will work) drop the address-of operator.
4574 if (!S.Context.hasSameUnqualifiedType(Var->getType(),
4575 ParamType.getNonReferenceType())) {
4576 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4578 S.Diag(Param->getLocation(), diag::note_template_param_here);
4582 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4584 << FixItHint::CreateRemoval(AddrOpLoc);
4585 S.Diag(Param->getLocation(), diag::note_template_param_here);
4587 ArgType = Var->getType();
4589 } else if (!AddressTaken && ParamType->isPointerType()) {
4590 if (Var->getType()->isArrayType()) {
4591 // Array-to-pointer decay.
4592 ArgType = S.Context.getArrayDecayedType(Var->getType());
4594 // If the template parameter has pointer type but the address of
4595 // this object was not taken, complain and (possibly) recover by
4596 // taking the address of the entity.
4597 ArgType = S.Context.getPointerType(Var->getType());
4598 if (!S.Context.hasSameUnqualifiedType(ArgType, ParamType)) {
4599 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of)
4601 S.Diag(Param->getLocation(), diag::note_template_param_here);
4605 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of)
4607 << FixItHint::CreateInsertion(Arg->getLocStart(), "&");
4609 S.Diag(Param->getLocation(), diag::note_template_param_here);
4614 if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType, ArgIn,
4618 // Create the template argument.
4620 TemplateArgument(cast<ValueDecl>(Entity->getCanonicalDecl()), ParamType);
4621 S.MarkAnyDeclReferenced(Arg->getLocStart(), Entity, false);
4625 /// \brief Checks whether the given template argument is a pointer to
4626 /// member constant according to C++ [temp.arg.nontype]p1.
4627 static bool CheckTemplateArgumentPointerToMember(Sema &S,
4628 NonTypeTemplateParmDecl *Param,
4631 TemplateArgument &Converted) {
4632 bool Invalid = false;
4634 // Check for a null pointer value.
4635 Expr *Arg = ResultArg;
4636 switch (isNullPointerValueTemplateArgument(S, Param, ParamType, Arg)) {
4639 case NPV_NullPointer:
4640 S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
4641 Converted = TemplateArgument(S.Context.getCanonicalType(ParamType),
4643 if (S.Context.getTargetInfo().getCXXABI().isMicrosoft())
4644 S.RequireCompleteType(Arg->getExprLoc(), ParamType, 0);
4646 case NPV_NotNullPointer:
4650 bool ObjCLifetimeConversion;
4651 if (S.IsQualificationConversion(Arg->getType(),
4652 ParamType.getNonReferenceType(),
4653 false, ObjCLifetimeConversion)) {
4654 Arg = S.ImpCastExprToType(Arg, ParamType, CK_NoOp,
4655 Arg->getValueKind()).get();
4657 } else if (!S.Context.hasSameUnqualifiedType(Arg->getType(),
4658 ParamType.getNonReferenceType())) {
4659 // We can't perform this conversion.
4660 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible)
4661 << Arg->getType() << ParamType << Arg->getSourceRange();
4662 S.Diag(Param->getLocation(), diag::note_template_param_here);
4666 // See through any implicit casts we added to fix the type.
4667 while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg))
4668 Arg = Cast->getSubExpr();
4670 // C++ [temp.arg.nontype]p1:
4672 // A template-argument for a non-type, non-template
4673 // template-parameter shall be one of: [...]
4675 // -- a pointer to member expressed as described in 5.3.1.
4676 DeclRefExpr *DRE = nullptr;
4678 // In C++98/03 mode, give an extension warning on any extra parentheses.
4679 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
4680 bool ExtraParens = false;
4681 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) {
4682 if (!Invalid && !ExtraParens) {
4683 S.Diag(Arg->getLocStart(),
4684 S.getLangOpts().CPlusPlus11 ?
4685 diag::warn_cxx98_compat_template_arg_extra_parens :
4686 diag::ext_template_arg_extra_parens)
4687 << Arg->getSourceRange();
4691 Arg = Parens->getSubExpr();
4694 while (SubstNonTypeTemplateParmExpr *subst =
4695 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
4696 Arg = subst->getReplacement()->IgnoreImpCasts();
4698 // A pointer-to-member constant written &Class::member.
4699 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
4700 if (UnOp->getOpcode() == UO_AddrOf) {
4701 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr());
4702 if (DRE && !DRE->getQualifier())
4706 // A constant of pointer-to-member type.
4707 else if ((DRE = dyn_cast<DeclRefExpr>(Arg))) {
4708 if (ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl())) {
4709 if (VD->getType()->isMemberPointerType()) {
4710 if (isa<NonTypeTemplateParmDecl>(VD)) {
4711 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
4712 Converted = TemplateArgument(Arg);
4714 VD = cast<ValueDecl>(VD->getCanonicalDecl());
4715 Converted = TemplateArgument(VD, ParamType);
4726 return S.Diag(Arg->getLocStart(),
4727 diag::err_template_arg_not_pointer_to_member_form)
4728 << Arg->getSourceRange();
4730 if (isa<FieldDecl>(DRE->getDecl()) ||
4731 isa<IndirectFieldDecl>(DRE->getDecl()) ||
4732 isa<CXXMethodDecl>(DRE->getDecl())) {
4733 assert((isa<FieldDecl>(DRE->getDecl()) ||
4734 isa<IndirectFieldDecl>(DRE->getDecl()) ||
4735 !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) &&
4736 "Only non-static member pointers can make it here");
4738 // Okay: this is the address of a non-static member, and therefore
4739 // a member pointer constant.
4740 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
4741 Converted = TemplateArgument(Arg);
4743 ValueDecl *D = cast<ValueDecl>(DRE->getDecl()->getCanonicalDecl());
4744 Converted = TemplateArgument(D, ParamType);
4749 // We found something else, but we don't know specifically what it is.
4750 S.Diag(Arg->getLocStart(),
4751 diag::err_template_arg_not_pointer_to_member_form)
4752 << Arg->getSourceRange();
4753 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here);
4757 /// \brief Check a template argument against its corresponding
4758 /// non-type template parameter.
4760 /// This routine implements the semantics of C++ [temp.arg.nontype].
4761 /// If an error occurred, it returns ExprError(); otherwise, it
4762 /// returns the converted template argument. \p
4763 /// InstantiatedParamType is the type of the non-type template
4764 /// parameter after it has been instantiated.
4765 ExprResult Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
4766 QualType InstantiatedParamType, Expr *Arg,
4767 TemplateArgument &Converted,
4768 CheckTemplateArgumentKind CTAK) {
4769 SourceLocation StartLoc = Arg->getLocStart();
4771 // If either the parameter has a dependent type or the argument is
4772 // type-dependent, there's nothing we can check now.
4773 if (InstantiatedParamType->isDependentType() || Arg->isTypeDependent()) {
4774 // FIXME: Produce a cloned, canonical expression?
4775 Converted = TemplateArgument(Arg);
4779 // C++ [temp.arg.nontype]p5:
4780 // The following conversions are performed on each expression used
4781 // as a non-type template-argument. If a non-type
4782 // template-argument cannot be converted to the type of the
4783 // corresponding template-parameter then the program is
4785 QualType ParamType = InstantiatedParamType;
4786 if (ParamType->isIntegralOrEnumerationType()) {
4788 // -- for a non-type template-parameter of integral or
4789 // enumeration type, conversions permitted in a converted
4790 // constant expression are applied.
4793 // -- for a non-type template-parameter of integral or
4794 // enumeration type, integral promotions (4.5) and integral
4795 // conversions (4.7) are applied.
4797 if (CTAK == CTAK_Deduced &&
4798 !Context.hasSameUnqualifiedType(ParamType, Arg->getType())) {
4799 // C++ [temp.deduct.type]p17:
4800 // If, in the declaration of a function template with a non-type
4801 // template-parameter, the non-type template-parameter is used
4802 // in an expression in the function parameter-list and, if the
4803 // corresponding template-argument is deduced, the
4804 // template-argument type shall match the type of the
4805 // template-parameter exactly, except that a template-argument
4806 // deduced from an array bound may be of any integral type.
4807 Diag(StartLoc, diag::err_deduced_non_type_template_arg_type_mismatch)
4808 << Arg->getType().getUnqualifiedType()
4809 << ParamType.getUnqualifiedType();
4810 Diag(Param->getLocation(), diag::note_template_param_here);
4814 if (getLangOpts().CPlusPlus11) {
4815 // We can't check arbitrary value-dependent arguments.
4816 // FIXME: If there's no viable conversion to the template parameter type,
4817 // we should be able to diagnose that prior to instantiation.
4818 if (Arg->isValueDependent()) {
4819 Converted = TemplateArgument(Arg);
4823 // C++ [temp.arg.nontype]p1:
4824 // A template-argument for a non-type, non-template template-parameter
4827 // -- for a non-type template-parameter of integral or enumeration
4828 // type, a converted constant expression of the type of the
4829 // template-parameter; or
4831 ExprResult ArgResult =
4832 CheckConvertedConstantExpression(Arg, ParamType, Value,
4834 if (ArgResult.isInvalid())
4837 // Widen the argument value to sizeof(parameter type). This is almost
4838 // always a no-op, except when the parameter type is bool. In
4839 // that case, this may extend the argument from 1 bit to 8 bits.
4840 QualType IntegerType = ParamType;
4841 if (const EnumType *Enum = IntegerType->getAs<EnumType>())
4842 IntegerType = Enum->getDecl()->getIntegerType();
4843 Value = Value.extOrTrunc(Context.getTypeSize(IntegerType));
4845 Converted = TemplateArgument(Context, Value,
4846 Context.getCanonicalType(ParamType));
4850 ExprResult ArgResult = DefaultLvalueConversion(Arg);
4851 if (ArgResult.isInvalid())
4853 Arg = ArgResult.get();
4855 QualType ArgType = Arg->getType();
4857 // C++ [temp.arg.nontype]p1:
4858 // A template-argument for a non-type, non-template
4859 // template-parameter shall be one of:
4861 // -- an integral constant-expression of integral or enumeration
4863 // -- the name of a non-type template-parameter; or
4864 SourceLocation NonConstantLoc;
4866 if (!ArgType->isIntegralOrEnumerationType()) {
4867 Diag(Arg->getLocStart(),
4868 diag::err_template_arg_not_integral_or_enumeral)
4869 << ArgType << Arg->getSourceRange();
4870 Diag(Param->getLocation(), diag::note_template_param_here);
4872 } else if (!Arg->isValueDependent()) {
4873 class TmplArgICEDiagnoser : public VerifyICEDiagnoser {
4877 TmplArgICEDiagnoser(QualType T) : T(T) { }
4879 void diagnoseNotICE(Sema &S, SourceLocation Loc,
4880 SourceRange SR) override {
4881 S.Diag(Loc, diag::err_template_arg_not_ice) << T << SR;
4883 } Diagnoser(ArgType);
4885 Arg = VerifyIntegerConstantExpression(Arg, &Value, Diagnoser,
4891 // From here on out, all we care about are the unqualified forms
4892 // of the parameter and argument types.
4893 ParamType = ParamType.getUnqualifiedType();
4894 ArgType = ArgType.getUnqualifiedType();
4896 // Try to convert the argument to the parameter's type.
4897 if (Context.hasSameType(ParamType, ArgType)) {
4898 // Okay: no conversion necessary
4899 } else if (ParamType->isBooleanType()) {
4900 // This is an integral-to-boolean conversion.
4901 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralToBoolean).get();
4902 } else if (IsIntegralPromotion(Arg, ArgType, ParamType) ||
4903 !ParamType->isEnumeralType()) {
4904 // This is an integral promotion or conversion.
4905 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralCast).get();
4907 // We can't perform this conversion.
4908 Diag(Arg->getLocStart(),
4909 diag::err_template_arg_not_convertible)
4910 << Arg->getType() << InstantiatedParamType << Arg->getSourceRange();
4911 Diag(Param->getLocation(), diag::note_template_param_here);
4915 // Add the value of this argument to the list of converted
4916 // arguments. We use the bitwidth and signedness of the template
4918 if (Arg->isValueDependent()) {
4919 // The argument is value-dependent. Create a new
4920 // TemplateArgument with the converted expression.
4921 Converted = TemplateArgument(Arg);
4925 QualType IntegerType = Context.getCanonicalType(ParamType);
4926 if (const EnumType *Enum = IntegerType->getAs<EnumType>())
4927 IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType());
4929 if (ParamType->isBooleanType()) {
4930 // Value must be zero or one.
4932 unsigned AllowedBits = Context.getTypeSize(IntegerType);
4933 if (Value.getBitWidth() != AllowedBits)
4934 Value = Value.extOrTrunc(AllowedBits);
4935 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
4937 llvm::APSInt OldValue = Value;
4939 // Coerce the template argument's value to the value it will have
4940 // based on the template parameter's type.
4941 unsigned AllowedBits = Context.getTypeSize(IntegerType);
4942 if (Value.getBitWidth() != AllowedBits)
4943 Value = Value.extOrTrunc(AllowedBits);
4944 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
4946 // Complain if an unsigned parameter received a negative value.
4947 if (IntegerType->isUnsignedIntegerOrEnumerationType()
4948 && (OldValue.isSigned() && OldValue.isNegative())) {
4949 Diag(Arg->getLocStart(), diag::warn_template_arg_negative)
4950 << OldValue.toString(10) << Value.toString(10) << Param->getType()
4951 << Arg->getSourceRange();
4952 Diag(Param->getLocation(), diag::note_template_param_here);
4955 // Complain if we overflowed the template parameter's type.
4956 unsigned RequiredBits;
4957 if (IntegerType->isUnsignedIntegerOrEnumerationType())
4958 RequiredBits = OldValue.getActiveBits();
4959 else if (OldValue.isUnsigned())
4960 RequiredBits = OldValue.getActiveBits() + 1;
4962 RequiredBits = OldValue.getMinSignedBits();
4963 if (RequiredBits > AllowedBits) {
4964 Diag(Arg->getLocStart(),
4965 diag::warn_template_arg_too_large)
4966 << OldValue.toString(10) << Value.toString(10) << Param->getType()
4967 << Arg->getSourceRange();
4968 Diag(Param->getLocation(), diag::note_template_param_here);
4972 Converted = TemplateArgument(Context, Value,
4973 ParamType->isEnumeralType()
4974 ? Context.getCanonicalType(ParamType)
4979 QualType ArgType = Arg->getType();
4980 DeclAccessPair FoundResult; // temporary for ResolveOverloadedFunction
4982 // Handle pointer-to-function, reference-to-function, and
4983 // pointer-to-member-function all in (roughly) the same way.
4984 if (// -- For a non-type template-parameter of type pointer to
4985 // function, only the function-to-pointer conversion (4.3) is
4986 // applied. If the template-argument represents a set of
4987 // overloaded functions (or a pointer to such), the matching
4988 // function is selected from the set (13.4).
4989 (ParamType->isPointerType() &&
4990 ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType()) ||
4991 // -- For a non-type template-parameter of type reference to
4992 // function, no conversions apply. If the template-argument
4993 // represents a set of overloaded functions, the matching
4994 // function is selected from the set (13.4).
4995 (ParamType->isReferenceType() &&
4996 ParamType->getAs<ReferenceType>()->getPointeeType()->isFunctionType()) ||
4997 // -- For a non-type template-parameter of type pointer to
4998 // member function, no conversions apply. If the
4999 // template-argument represents a set of overloaded member
5000 // functions, the matching member function is selected from
5002 (ParamType->isMemberPointerType() &&
5003 ParamType->getAs<MemberPointerType>()->getPointeeType()
5004 ->isFunctionType())) {
5006 if (Arg->getType() == Context.OverloadTy) {
5007 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType,
5010 if (DiagnoseUseOfDecl(Fn, Arg->getLocStart()))
5013 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
5014 ArgType = Arg->getType();
5019 if (!ParamType->isMemberPointerType()) {
5020 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5027 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
5033 if (ParamType->isPointerType()) {
5034 // -- for a non-type template-parameter of type pointer to
5035 // object, qualification conversions (4.4) and the
5036 // array-to-pointer conversion (4.2) are applied.
5037 // C++0x also allows a value of std::nullptr_t.
5038 assert(ParamType->getPointeeType()->isIncompleteOrObjectType() &&
5039 "Only object pointers allowed here");
5041 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5048 if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) {
5049 // -- For a non-type template-parameter of type reference to
5050 // object, no conversions apply. The type referred to by the
5051 // reference may be more cv-qualified than the (otherwise
5052 // identical) type of the template-argument. The
5053 // template-parameter is bound directly to the
5054 // template-argument, which must be an lvalue.
5055 assert(ParamRefType->getPointeeType()->isIncompleteOrObjectType() &&
5056 "Only object references allowed here");
5058 if (Arg->getType() == Context.OverloadTy) {
5059 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg,
5060 ParamRefType->getPointeeType(),
5063 if (DiagnoseUseOfDecl(Fn, Arg->getLocStart()))
5066 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
5067 ArgType = Arg->getType();
5072 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5079 // Deal with parameters of type std::nullptr_t.
5080 if (ParamType->isNullPtrType()) {
5081 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
5082 Converted = TemplateArgument(Arg);
5086 switch (isNullPointerValueTemplateArgument(*this, Param, ParamType, Arg)) {
5087 case NPV_NotNullPointer:
5088 Diag(Arg->getExprLoc(), diag::err_template_arg_not_convertible)
5089 << Arg->getType() << ParamType;
5090 Diag(Param->getLocation(), diag::note_template_param_here);
5096 case NPV_NullPointer:
5097 Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
5098 Converted = TemplateArgument(Context.getCanonicalType(ParamType),
5104 // -- For a non-type template-parameter of type pointer to data
5105 // member, qualification conversions (4.4) are applied.
5106 assert(ParamType->isMemberPointerType() && "Only pointers to members remain");
5108 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
5114 /// \brief Check a template argument against its corresponding
5115 /// template template parameter.
5117 /// This routine implements the semantics of C++ [temp.arg.template].
5118 /// It returns true if an error occurred, and false otherwise.
5119 bool Sema::CheckTemplateArgument(TemplateTemplateParmDecl *Param,
5120 TemplateArgumentLoc &Arg,
5121 unsigned ArgumentPackIndex) {
5122 TemplateName Name = Arg.getArgument().getAsTemplateOrTemplatePattern();
5123 TemplateDecl *Template = Name.getAsTemplateDecl();
5125 // Any dependent template name is fine.
5126 assert(Name.isDependent() && "Non-dependent template isn't a declaration?");
5130 // C++0x [temp.arg.template]p1:
5131 // A template-argument for a template template-parameter shall be
5132 // the name of a class template or an alias template, expressed as an
5133 // id-expression. When the template-argument names a class template, only
5134 // primary class templates are considered when matching the
5135 // template template argument with the corresponding parameter;
5136 // partial specializations are not considered even if their
5137 // parameter lists match that of the template template parameter.
5139 // Note that we also allow template template parameters here, which
5140 // will happen when we are dealing with, e.g., class template
5141 // partial specializations.
5142 if (!isa<ClassTemplateDecl>(Template) &&
5143 !isa<TemplateTemplateParmDecl>(Template) &&
5144 !isa<TypeAliasTemplateDecl>(Template)) {
5145 assert(isa<FunctionTemplateDecl>(Template) &&
5146 "Only function templates are possible here");
5147 Diag(Arg.getLocation(), diag::err_template_arg_not_class_template);
5148 Diag(Template->getLocation(), diag::note_template_arg_refers_here_func)
5152 TemplateParameterList *Params = Param->getTemplateParameters();
5153 if (Param->isExpandedParameterPack())
5154 Params = Param->getExpansionTemplateParameters(ArgumentPackIndex);
5156 return !TemplateParameterListsAreEqual(Template->getTemplateParameters(),
5159 TPL_TemplateTemplateArgumentMatch,
5163 /// \brief Given a non-type template argument that refers to a
5164 /// declaration and the type of its corresponding non-type template
5165 /// parameter, produce an expression that properly refers to that
5168 Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
5170 SourceLocation Loc) {
5171 // C++ [temp.param]p8:
5173 // A non-type template-parameter of type "array of T" or
5174 // "function returning T" is adjusted to be of type "pointer to
5175 // T" or "pointer to function returning T", respectively.
5176 if (ParamType->isArrayType())
5177 ParamType = Context.getArrayDecayedType(ParamType);
5178 else if (ParamType->isFunctionType())
5179 ParamType = Context.getPointerType(ParamType);
5181 // For a NULL non-type template argument, return nullptr casted to the
5182 // parameter's type.
5183 if (Arg.getKind() == TemplateArgument::NullPtr) {
5184 return ImpCastExprToType(
5185 new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc),
5187 ParamType->getAs<MemberPointerType>()
5188 ? CK_NullToMemberPointer
5189 : CK_NullToPointer);
5191 assert(Arg.getKind() == TemplateArgument::Declaration &&
5192 "Only declaration template arguments permitted here");
5194 ValueDecl *VD = cast<ValueDecl>(Arg.getAsDecl());
5196 if (VD->getDeclContext()->isRecord() &&
5197 (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD) ||
5198 isa<IndirectFieldDecl>(VD))) {
5199 // If the value is a class member, we might have a pointer-to-member.
5200 // Determine whether the non-type template template parameter is of
5201 // pointer-to-member type. If so, we need to build an appropriate
5202 // expression for a pointer-to-member, since a "normal" DeclRefExpr
5203 // would refer to the member itself.
5204 if (ParamType->isMemberPointerType()) {
5206 = Context.getTypeDeclType(cast<RecordDecl>(VD->getDeclContext()));
5207 NestedNameSpecifier *Qualifier
5208 = NestedNameSpecifier::Create(Context, nullptr, false,
5209 ClassType.getTypePtr());
5211 SS.MakeTrivial(Context, Qualifier, Loc);
5213 // The actual value-ness of this is unimportant, but for
5214 // internal consistency's sake, references to instance methods
5216 ExprValueKind VK = VK_LValue;
5217 if (isa<CXXMethodDecl>(VD) && cast<CXXMethodDecl>(VD)->isInstance())
5220 ExprResult RefExpr = BuildDeclRefExpr(VD,
5221 VD->getType().getNonReferenceType(),
5225 if (RefExpr.isInvalid())
5228 RefExpr = CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
5230 // We might need to perform a trailing qualification conversion, since
5231 // the element type on the parameter could be more qualified than the
5232 // element type in the expression we constructed.
5233 bool ObjCLifetimeConversion;
5234 if (IsQualificationConversion(((Expr*) RefExpr.get())->getType(),
5235 ParamType.getUnqualifiedType(), false,
5236 ObjCLifetimeConversion))
5237 RefExpr = ImpCastExprToType(RefExpr.get(), ParamType.getUnqualifiedType(), CK_NoOp);
5239 assert(!RefExpr.isInvalid() &&
5240 Context.hasSameType(((Expr*) RefExpr.get())->getType(),
5241 ParamType.getUnqualifiedType()));
5246 QualType T = VD->getType().getNonReferenceType();
5248 if (ParamType->isPointerType()) {
5249 // When the non-type template parameter is a pointer, take the
5250 // address of the declaration.
5251 ExprResult RefExpr = BuildDeclRefExpr(VD, T, VK_LValue, Loc);
5252 if (RefExpr.isInvalid())
5255 if (T->isFunctionType() || T->isArrayType()) {
5256 // Decay functions and arrays.
5257 RefExpr = DefaultFunctionArrayConversion(RefExpr.get());
5258 if (RefExpr.isInvalid())
5264 // Take the address of everything else
5265 return CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
5268 ExprValueKind VK = VK_RValue;
5270 // If the non-type template parameter has reference type, qualify the
5271 // resulting declaration reference with the extra qualifiers on the
5272 // type that the reference refers to.
5273 if (const ReferenceType *TargetRef = ParamType->getAs<ReferenceType>()) {
5275 T = Context.getQualifiedType(T,
5276 TargetRef->getPointeeType().getQualifiers());
5277 } else if (isa<FunctionDecl>(VD)) {
5278 // References to functions are always lvalues.
5282 return BuildDeclRefExpr(VD, T, VK, Loc);
5285 /// \brief Construct a new expression that refers to the given
5286 /// integral template argument with the given source-location
5289 /// This routine takes care of the mapping from an integral template
5290 /// argument (which may have any integral type) to the appropriate
5293 Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg,
5294 SourceLocation Loc) {
5295 assert(Arg.getKind() == TemplateArgument::Integral &&
5296 "Operation is only valid for integral template arguments");
5297 QualType OrigT = Arg.getIntegralType();
5299 // If this is an enum type that we're instantiating, we need to use an integer
5300 // type the same size as the enumerator. We don't want to build an
5301 // IntegerLiteral with enum type. The integer type of an enum type can be of
5302 // any integral type with C++11 enum classes, make sure we create the right
5303 // type of literal for it.
5305 if (const EnumType *ET = OrigT->getAs<EnumType>())
5306 T = ET->getDecl()->getIntegerType();
5309 if (T->isAnyCharacterType()) {
5310 CharacterLiteral::CharacterKind Kind;
5311 if (T->isWideCharType())
5312 Kind = CharacterLiteral::Wide;
5313 else if (T->isChar16Type())
5314 Kind = CharacterLiteral::UTF16;
5315 else if (T->isChar32Type())
5316 Kind = CharacterLiteral::UTF32;
5318 Kind = CharacterLiteral::Ascii;
5320 E = new (Context) CharacterLiteral(Arg.getAsIntegral().getZExtValue(),
5322 } else if (T->isBooleanType()) {
5323 E = new (Context) CXXBoolLiteralExpr(Arg.getAsIntegral().getBoolValue(),
5325 } else if (T->isNullPtrType()) {
5326 E = new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
5328 E = IntegerLiteral::Create(Context, Arg.getAsIntegral(), T, Loc);
5331 if (OrigT->isEnumeralType()) {
5332 // FIXME: This is a hack. We need a better way to handle substituted
5333 // non-type template parameters.
5334 E = CStyleCastExpr::Create(Context, OrigT, VK_RValue, CK_IntegralCast, E,
5336 Context.getTrivialTypeSourceInfo(OrigT, Loc),
5343 /// \brief Match two template parameters within template parameter lists.
5344 static bool MatchTemplateParameterKind(Sema &S, NamedDecl *New, NamedDecl *Old,
5346 Sema::TemplateParameterListEqualKind Kind,
5347 SourceLocation TemplateArgLoc) {
5348 // Check the actual kind (type, non-type, template).
5349 if (Old->getKind() != New->getKind()) {
5351 unsigned NextDiag = diag::err_template_param_different_kind;
5352 if (TemplateArgLoc.isValid()) {
5353 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
5354 NextDiag = diag::note_template_param_different_kind;
5356 S.Diag(New->getLocation(), NextDiag)
5357 << (Kind != Sema::TPL_TemplateMatch);
5358 S.Diag(Old->getLocation(), diag::note_template_prev_declaration)
5359 << (Kind != Sema::TPL_TemplateMatch);
5365 // Check that both are parameter packs are neither are parameter packs.
5366 // However, if we are matching a template template argument to a
5367 // template template parameter, the template template parameter can have
5368 // a parameter pack where the template template argument does not.
5369 if (Old->isTemplateParameterPack() != New->isTemplateParameterPack() &&
5370 !(Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
5371 Old->isTemplateParameterPack())) {
5373 unsigned NextDiag = diag::err_template_parameter_pack_non_pack;
5374 if (TemplateArgLoc.isValid()) {
5375 S.Diag(TemplateArgLoc,
5376 diag::err_template_arg_template_params_mismatch);
5377 NextDiag = diag::note_template_parameter_pack_non_pack;
5380 unsigned ParamKind = isa<TemplateTypeParmDecl>(New)? 0
5381 : isa<NonTypeTemplateParmDecl>(New)? 1
5383 S.Diag(New->getLocation(), NextDiag)
5384 << ParamKind << New->isParameterPack();
5385 S.Diag(Old->getLocation(), diag::note_template_parameter_pack_here)
5386 << ParamKind << Old->isParameterPack();
5392 // For non-type template parameters, check the type of the parameter.
5393 if (NonTypeTemplateParmDecl *OldNTTP
5394 = dyn_cast<NonTypeTemplateParmDecl>(Old)) {
5395 NonTypeTemplateParmDecl *NewNTTP = cast<NonTypeTemplateParmDecl>(New);
5397 // If we are matching a template template argument to a template
5398 // template parameter and one of the non-type template parameter types
5399 // is dependent, then we must wait until template instantiation time
5400 // to actually compare the arguments.
5401 if (Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
5402 (OldNTTP->getType()->isDependentType() ||
5403 NewNTTP->getType()->isDependentType()))
5406 if (!S.Context.hasSameType(OldNTTP->getType(), NewNTTP->getType())) {
5408 unsigned NextDiag = diag::err_template_nontype_parm_different_type;
5409 if (TemplateArgLoc.isValid()) {
5410 S.Diag(TemplateArgLoc,
5411 diag::err_template_arg_template_params_mismatch);
5412 NextDiag = diag::note_template_nontype_parm_different_type;
5414 S.Diag(NewNTTP->getLocation(), NextDiag)
5415 << NewNTTP->getType()
5416 << (Kind != Sema::TPL_TemplateMatch);
5417 S.Diag(OldNTTP->getLocation(),
5418 diag::note_template_nontype_parm_prev_declaration)
5419 << OldNTTP->getType();
5428 // For template template parameters, check the template parameter types.
5429 // The template parameter lists of template template
5430 // parameters must agree.
5431 if (TemplateTemplateParmDecl *OldTTP
5432 = dyn_cast<TemplateTemplateParmDecl>(Old)) {
5433 TemplateTemplateParmDecl *NewTTP = cast<TemplateTemplateParmDecl>(New);
5434 return S.TemplateParameterListsAreEqual(NewTTP->getTemplateParameters(),
5435 OldTTP->getTemplateParameters(),
5437 (Kind == Sema::TPL_TemplateMatch
5438 ? Sema::TPL_TemplateTemplateParmMatch
5446 /// \brief Diagnose a known arity mismatch when comparing template argument
5449 void DiagnoseTemplateParameterListArityMismatch(Sema &S,
5450 TemplateParameterList *New,
5451 TemplateParameterList *Old,
5452 Sema::TemplateParameterListEqualKind Kind,
5453 SourceLocation TemplateArgLoc) {
5454 unsigned NextDiag = diag::err_template_param_list_different_arity;
5455 if (TemplateArgLoc.isValid()) {
5456 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
5457 NextDiag = diag::note_template_param_list_different_arity;
5459 S.Diag(New->getTemplateLoc(), NextDiag)
5460 << (New->size() > Old->size())
5461 << (Kind != Sema::TPL_TemplateMatch)
5462 << SourceRange(New->getTemplateLoc(), New->getRAngleLoc());
5463 S.Diag(Old->getTemplateLoc(), diag::note_template_prev_declaration)
5464 << (Kind != Sema::TPL_TemplateMatch)
5465 << SourceRange(Old->getTemplateLoc(), Old->getRAngleLoc());
5468 /// \brief Determine whether the given template parameter lists are
5471 /// \param New The new template parameter list, typically written in the
5472 /// source code as part of a new template declaration.
5474 /// \param Old The old template parameter list, typically found via
5475 /// name lookup of the template declared with this template parameter
5478 /// \param Complain If true, this routine will produce a diagnostic if
5479 /// the template parameter lists are not equivalent.
5481 /// \param Kind describes how we are to match the template parameter lists.
5483 /// \param TemplateArgLoc If this source location is valid, then we
5484 /// are actually checking the template parameter list of a template
5485 /// argument (New) against the template parameter list of its
5486 /// corresponding template template parameter (Old). We produce
5487 /// slightly different diagnostics in this scenario.
5489 /// \returns True if the template parameter lists are equal, false
5492 Sema::TemplateParameterListsAreEqual(TemplateParameterList *New,
5493 TemplateParameterList *Old,
5495 TemplateParameterListEqualKind Kind,
5496 SourceLocation TemplateArgLoc) {
5497 if (Old->size() != New->size() && Kind != TPL_TemplateTemplateArgumentMatch) {
5499 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
5505 // C++0x [temp.arg.template]p3:
5506 // A template-argument matches a template template-parameter (call it P)
5507 // when each of the template parameters in the template-parameter-list of
5508 // the template-argument's corresponding class template or alias template
5509 // (call it A) matches the corresponding template parameter in the
5510 // template-parameter-list of P. [...]
5511 TemplateParameterList::iterator NewParm = New->begin();
5512 TemplateParameterList::iterator NewParmEnd = New->end();
5513 for (TemplateParameterList::iterator OldParm = Old->begin(),
5514 OldParmEnd = Old->end();
5515 OldParm != OldParmEnd; ++OldParm) {
5516 if (Kind != TPL_TemplateTemplateArgumentMatch ||
5517 !(*OldParm)->isTemplateParameterPack()) {
5518 if (NewParm == NewParmEnd) {
5520 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
5526 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
5527 Kind, TemplateArgLoc))
5534 // C++0x [temp.arg.template]p3:
5535 // [...] When P's template- parameter-list contains a template parameter
5536 // pack (14.5.3), the template parameter pack will match zero or more
5537 // template parameters or template parameter packs in the
5538 // template-parameter-list of A with the same type and form as the
5539 // template parameter pack in P (ignoring whether those template
5540 // parameters are template parameter packs).
5541 for (; NewParm != NewParmEnd; ++NewParm) {
5542 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
5543 Kind, TemplateArgLoc))
5548 // Make sure we exhausted all of the arguments.
5549 if (NewParm != NewParmEnd) {
5551 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
5560 /// \brief Check whether a template can be declared within this scope.
5562 /// If the template declaration is valid in this scope, returns
5563 /// false. Otherwise, issues a diagnostic and returns true.
5565 Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) {
5569 // Find the nearest enclosing declaration scope.
5570 while ((S->getFlags() & Scope::DeclScope) == 0 ||
5571 (S->getFlags() & Scope::TemplateParamScope) != 0)
5575 // A template [...] shall not have C linkage.
5576 DeclContext *Ctx = S->getEntity();
5577 if (Ctx && Ctx->isExternCContext())
5578 return Diag(TemplateParams->getTemplateLoc(), diag::err_template_linkage)
5579 << TemplateParams->getSourceRange();
5581 while (Ctx && isa<LinkageSpecDecl>(Ctx))
5582 Ctx = Ctx->getParent();
5585 // A template-declaration can appear only as a namespace scope or
5586 // class scope declaration.
5588 if (Ctx->isFileContext())
5590 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Ctx)) {
5591 // C++ [temp.mem]p2:
5592 // A local class shall not have member templates.
5593 if (RD->isLocalClass())
5594 return Diag(TemplateParams->getTemplateLoc(),
5595 diag::err_template_inside_local_class)
5596 << TemplateParams->getSourceRange();
5602 return Diag(TemplateParams->getTemplateLoc(),
5603 diag::err_template_outside_namespace_or_class_scope)
5604 << TemplateParams->getSourceRange();
5607 /// \brief Determine what kind of template specialization the given declaration
5609 static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D) {
5611 return TSK_Undeclared;
5613 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D))
5614 return Record->getTemplateSpecializationKind();
5615 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D))
5616 return Function->getTemplateSpecializationKind();
5617 if (VarDecl *Var = dyn_cast<VarDecl>(D))
5618 return Var->getTemplateSpecializationKind();
5620 return TSK_Undeclared;
5623 /// \brief Check whether a specialization is well-formed in the current
5626 /// This routine determines whether a template specialization can be declared
5627 /// in the current context (C++ [temp.expl.spec]p2).
5629 /// \param S the semantic analysis object for which this check is being
5632 /// \param Specialized the entity being specialized or instantiated, which
5633 /// may be a kind of template (class template, function template, etc.) or
5634 /// a member of a class template (member function, static data member,
5637 /// \param PrevDecl the previous declaration of this entity, if any.
5639 /// \param Loc the location of the explicit specialization or instantiation of
5642 /// \param IsPartialSpecialization whether this is a partial specialization of
5643 /// a class template.
5645 /// \returns true if there was an error that we cannot recover from, false
5647 static bool CheckTemplateSpecializationScope(Sema &S,
5648 NamedDecl *Specialized,
5649 NamedDecl *PrevDecl,
5651 bool IsPartialSpecialization) {
5652 // Keep these "kind" numbers in sync with the %select statements in the
5653 // various diagnostics emitted by this routine.
5655 if (isa<ClassTemplateDecl>(Specialized))
5656 EntityKind = IsPartialSpecialization? 1 : 0;
5657 else if (isa<VarTemplateDecl>(Specialized))
5658 EntityKind = IsPartialSpecialization ? 3 : 2;
5659 else if (isa<FunctionTemplateDecl>(Specialized))
5661 else if (isa<CXXMethodDecl>(Specialized))
5663 else if (isa<VarDecl>(Specialized))
5665 else if (isa<RecordDecl>(Specialized))
5667 else if (isa<EnumDecl>(Specialized) && S.getLangOpts().CPlusPlus11)
5670 S.Diag(Loc, diag::err_template_spec_unknown_kind)
5671 << S.getLangOpts().CPlusPlus11;
5672 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
5676 // C++ [temp.expl.spec]p2:
5677 // An explicit specialization shall be declared in the namespace
5678 // of which the template is a member, or, for member templates, in
5679 // the namespace of which the enclosing class or enclosing class
5680 // template is a member. An explicit specialization of a member
5681 // function, member class or static data member of a class
5682 // template shall be declared in the namespace of which the class
5683 // template is a member. Such a declaration may also be a
5684 // definition. If the declaration is not a definition, the
5685 // specialization may be defined later in the name- space in which
5686 // the explicit specialization was declared, or in a namespace
5687 // that encloses the one in which the explicit specialization was
5689 if (S.CurContext->getRedeclContext()->isFunctionOrMethod()) {
5690 S.Diag(Loc, diag::err_template_spec_decl_function_scope)
5695 if (S.CurContext->isRecord() && !IsPartialSpecialization) {
5696 if (S.getLangOpts().MicrosoftExt) {
5697 // Do not warn for class scope explicit specialization during
5698 // instantiation, warning was already emitted during pattern
5699 // semantic analysis.
5700 if (!S.ActiveTemplateInstantiations.size())
5701 S.Diag(Loc, diag::ext_function_specialization_in_class)
5704 S.Diag(Loc, diag::err_template_spec_decl_class_scope)
5710 if (S.CurContext->isRecord() &&
5711 !S.CurContext->Equals(Specialized->getDeclContext())) {
5712 // Make sure that we're specializing in the right record context.
5713 // Otherwise, things can go horribly wrong.
5714 S.Diag(Loc, diag::err_template_spec_decl_class_scope)
5719 // C++ [temp.class.spec]p6:
5720 // A class template partial specialization may be declared or redeclared
5721 // in any namespace scope in which its definition may be defined (14.5.1
5723 DeclContext *SpecializedContext
5724 = Specialized->getDeclContext()->getEnclosingNamespaceContext();
5725 DeclContext *DC = S.CurContext->getEnclosingNamespaceContext();
5727 // Make sure that this redeclaration (or definition) occurs in an enclosing
5729 // Note that HandleDeclarator() performs this check for explicit
5730 // specializations of function templates, static data members, and member
5731 // functions, so we skip the check here for those kinds of entities.
5732 // FIXME: HandleDeclarator's diagnostics aren't quite as good, though.
5733 // Should we refactor that check, so that it occurs later?
5734 if (!DC->Encloses(SpecializedContext) &&
5735 !(isa<FunctionTemplateDecl>(Specialized) ||
5736 isa<FunctionDecl>(Specialized) ||
5737 isa<VarTemplateDecl>(Specialized) ||
5738 isa<VarDecl>(Specialized))) {
5739 if (isa<TranslationUnitDecl>(SpecializedContext))
5740 S.Diag(Loc, diag::err_template_spec_redecl_global_scope)
5741 << EntityKind << Specialized;
5742 else if (isa<NamespaceDecl>(SpecializedContext))
5743 S.Diag(Loc, diag::err_template_spec_redecl_out_of_scope)
5744 << EntityKind << Specialized
5745 << cast<NamedDecl>(SpecializedContext);
5747 llvm_unreachable("unexpected namespace context for specialization");
5749 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
5750 } else if ((!PrevDecl ||
5751 getTemplateSpecializationKind(PrevDecl) == TSK_Undeclared ||
5752 getTemplateSpecializationKind(PrevDecl) ==
5753 TSK_ImplicitInstantiation)) {
5754 // C++ [temp.exp.spec]p2:
5755 // An explicit specialization shall be declared in the namespace of which
5756 // the template is a member, or, for member templates, in the namespace
5757 // of which the enclosing class or enclosing class template is a member.
5758 // An explicit specialization of a member function, member class or
5759 // static data member of a class template shall be declared in the
5760 // namespace of which the class template is a member.
5762 // C++11 [temp.expl.spec]p2:
5763 // An explicit specialization shall be declared in a namespace enclosing
5764 // the specialized template.
5765 // C++11 [temp.explicit]p3:
5766 // An explicit instantiation shall appear in an enclosing namespace of its
5768 if (!DC->InEnclosingNamespaceSetOf(SpecializedContext)) {
5769 bool IsCPlusPlus11Extension = DC->Encloses(SpecializedContext);
5770 if (isa<TranslationUnitDecl>(SpecializedContext)) {
5771 assert(!IsCPlusPlus11Extension &&
5772 "DC encloses TU but isn't in enclosing namespace set");
5773 S.Diag(Loc, diag::err_template_spec_decl_out_of_scope_global)
5774 << EntityKind << Specialized;
5775 } else if (isa<NamespaceDecl>(SpecializedContext)) {
5777 if (!IsCPlusPlus11Extension)
5778 Diag = diag::err_template_spec_decl_out_of_scope;
5779 else if (!S.getLangOpts().CPlusPlus11)
5780 Diag = diag::ext_template_spec_decl_out_of_scope;
5782 Diag = diag::warn_cxx98_compat_template_spec_decl_out_of_scope;
5784 << EntityKind << Specialized << cast<NamedDecl>(SpecializedContext);
5787 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
5794 static SourceRange findTemplateParameter(unsigned Depth, Expr *E) {
5795 if (!E->isInstantiationDependent())
5796 return SourceLocation();
5797 DependencyChecker Checker(Depth);
5798 Checker.TraverseStmt(E);
5799 if (Checker.Match && Checker.MatchLoc.isInvalid())
5800 return E->getSourceRange();
5801 return Checker.MatchLoc;
5804 static SourceRange findTemplateParameter(unsigned Depth, TypeLoc TL) {
5805 if (!TL.getType()->isDependentType())
5806 return SourceLocation();
5807 DependencyChecker Checker(Depth);
5808 Checker.TraverseTypeLoc(TL);
5809 if (Checker.Match && Checker.MatchLoc.isInvalid())
5810 return TL.getSourceRange();
5811 return Checker.MatchLoc;
5814 /// \brief Subroutine of Sema::CheckTemplatePartialSpecializationArgs
5815 /// that checks non-type template partial specialization arguments.
5816 static bool CheckNonTypeTemplatePartialSpecializationArgs(
5817 Sema &S, SourceLocation TemplateNameLoc, NonTypeTemplateParmDecl *Param,
5818 const TemplateArgument *Args, unsigned NumArgs, bool IsDefaultArgument) {
5819 for (unsigned I = 0; I != NumArgs; ++I) {
5820 if (Args[I].getKind() == TemplateArgument::Pack) {
5821 if (CheckNonTypeTemplatePartialSpecializationArgs(
5822 S, TemplateNameLoc, Param, Args[I].pack_begin(),
5823 Args[I].pack_size(), IsDefaultArgument))
5829 if (Args[I].getKind() != TemplateArgument::Expression)
5832 Expr *ArgExpr = Args[I].getAsExpr();
5834 // We can have a pack expansion of any of the bullets below.
5835 if (PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(ArgExpr))
5836 ArgExpr = Expansion->getPattern();
5838 // Strip off any implicit casts we added as part of type checking.
5839 while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
5840 ArgExpr = ICE->getSubExpr();
5842 // C++ [temp.class.spec]p8:
5843 // A non-type argument is non-specialized if it is the name of a
5844 // non-type parameter. All other non-type arguments are
5847 // Below, we check the two conditions that only apply to
5848 // specialized non-type arguments, so skip any non-specialized
5850 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ArgExpr))
5851 if (isa<NonTypeTemplateParmDecl>(DRE->getDecl()))
5854 // C++ [temp.class.spec]p9:
5855 // Within the argument list of a class template partial
5856 // specialization, the following restrictions apply:
5857 // -- A partially specialized non-type argument expression
5858 // shall not involve a template parameter of the partial
5859 // specialization except when the argument expression is a
5860 // simple identifier.
5861 SourceRange ParamUseRange =
5862 findTemplateParameter(Param->getDepth(), ArgExpr);
5863 if (ParamUseRange.isValid()) {
5864 if (IsDefaultArgument) {
5865 S.Diag(TemplateNameLoc,
5866 diag::err_dependent_non_type_arg_in_partial_spec);
5867 S.Diag(ParamUseRange.getBegin(),
5868 diag::note_dependent_non_type_default_arg_in_partial_spec)
5871 S.Diag(ParamUseRange.getBegin(),
5872 diag::err_dependent_non_type_arg_in_partial_spec)
5878 // -- The type of a template parameter corresponding to a
5879 // specialized non-type argument shall not be dependent on a
5880 // parameter of the specialization.
5882 // FIXME: We need to delay this check until instantiation in some cases:
5884 // template<template<typename> class X> struct A {
5885 // template<typename T, X<T> N> struct B;
5886 // template<typename T> struct B<T, 0>;
5888 // template<typename> using X = int;
5889 // A<X>::B<int, 0> b;
5890 ParamUseRange = findTemplateParameter(
5891 Param->getDepth(), Param->getTypeSourceInfo()->getTypeLoc());
5892 if (ParamUseRange.isValid()) {
5893 S.Diag(IsDefaultArgument ? TemplateNameLoc : ArgExpr->getLocStart(),
5894 diag::err_dependent_typed_non_type_arg_in_partial_spec)
5895 << Param->getType() << ParamUseRange;
5896 S.Diag(Param->getLocation(), diag::note_template_param_here)
5897 << (IsDefaultArgument ? ParamUseRange : SourceRange());
5905 /// \brief Check the non-type template arguments of a class template
5906 /// partial specialization according to C++ [temp.class.spec]p9.
5908 /// \param TemplateNameLoc the location of the template name.
5909 /// \param TemplateParams the template parameters of the primary class
5911 /// \param NumExplicit the number of explicitly-specified template arguments.
5912 /// \param TemplateArgs the template arguments of the class template
5913 /// partial specialization.
5915 /// \returns \c true if there was an error, \c false otherwise.
5916 static bool CheckTemplatePartialSpecializationArgs(
5917 Sema &S, SourceLocation TemplateNameLoc,
5918 TemplateParameterList *TemplateParams, unsigned NumExplicit,
5919 SmallVectorImpl<TemplateArgument> &TemplateArgs) {
5920 const TemplateArgument *ArgList = TemplateArgs.data();
5922 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
5923 NonTypeTemplateParmDecl *Param
5924 = dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(I));
5928 if (CheckNonTypeTemplatePartialSpecializationArgs(
5929 S, TemplateNameLoc, Param, &ArgList[I], 1, I >= NumExplicit))
5937 Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec,
5939 SourceLocation KWLoc,
5940 SourceLocation ModulePrivateLoc,
5941 TemplateIdAnnotation &TemplateId,
5942 AttributeList *Attr,
5943 MultiTemplateParamsArg TemplateParameterLists) {
5944 assert(TUK != TUK_Reference && "References are not specializations");
5946 CXXScopeSpec &SS = TemplateId.SS;
5948 // NOTE: KWLoc is the location of the tag keyword. This will instead
5949 // store the location of the outermost template keyword in the declaration.
5950 SourceLocation TemplateKWLoc = TemplateParameterLists.size() > 0
5951 ? TemplateParameterLists[0]->getTemplateLoc() : KWLoc;
5952 SourceLocation TemplateNameLoc = TemplateId.TemplateNameLoc;
5953 SourceLocation LAngleLoc = TemplateId.LAngleLoc;
5954 SourceLocation RAngleLoc = TemplateId.RAngleLoc;
5956 // Find the class template we're specializing
5957 TemplateName Name = TemplateId.Template.get();
5958 ClassTemplateDecl *ClassTemplate
5959 = dyn_cast_or_null<ClassTemplateDecl>(Name.getAsTemplateDecl());
5961 if (!ClassTemplate) {
5962 Diag(TemplateNameLoc, diag::err_not_class_template_specialization)
5963 << (Name.getAsTemplateDecl() &&
5964 isa<TemplateTemplateParmDecl>(Name.getAsTemplateDecl()));
5968 bool isExplicitSpecialization = false;
5969 bool isPartialSpecialization = false;
5971 // Check the validity of the template headers that introduce this
5973 // FIXME: We probably shouldn't complain about these headers for
5974 // friend declarations.
5975 bool Invalid = false;
5976 TemplateParameterList *TemplateParams =
5977 MatchTemplateParametersToScopeSpecifier(
5978 KWLoc, TemplateNameLoc, SS, &TemplateId,
5979 TemplateParameterLists, TUK == TUK_Friend, isExplicitSpecialization,
5984 if (TemplateParams && TemplateParams->size() > 0) {
5985 isPartialSpecialization = true;
5987 if (TUK == TUK_Friend) {
5988 Diag(KWLoc, diag::err_partial_specialization_friend)
5989 << SourceRange(LAngleLoc, RAngleLoc);
5993 // C++ [temp.class.spec]p10:
5994 // The template parameter list of a specialization shall not
5995 // contain default template argument values.
5996 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
5997 Decl *Param = TemplateParams->getParam(I);
5998 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) {
5999 if (TTP->hasDefaultArgument()) {
6000 Diag(TTP->getDefaultArgumentLoc(),
6001 diag::err_default_arg_in_partial_spec);
6002 TTP->removeDefaultArgument();
6004 } else if (NonTypeTemplateParmDecl *NTTP
6005 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
6006 if (Expr *DefArg = NTTP->getDefaultArgument()) {
6007 Diag(NTTP->getDefaultArgumentLoc(),
6008 diag::err_default_arg_in_partial_spec)
6009 << DefArg->getSourceRange();
6010 NTTP->removeDefaultArgument();
6013 TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(Param);
6014 if (TTP->hasDefaultArgument()) {
6015 Diag(TTP->getDefaultArgument().getLocation(),
6016 diag::err_default_arg_in_partial_spec)
6017 << TTP->getDefaultArgument().getSourceRange();
6018 TTP->removeDefaultArgument();
6022 } else if (TemplateParams) {
6023 if (TUK == TUK_Friend)
6024 Diag(KWLoc, diag::err_template_spec_friend)
6025 << FixItHint::CreateRemoval(
6026 SourceRange(TemplateParams->getTemplateLoc(),
6027 TemplateParams->getRAngleLoc()))
6028 << SourceRange(LAngleLoc, RAngleLoc);
6030 isExplicitSpecialization = true;
6032 assert(TUK == TUK_Friend && "should have a 'template<>' for this decl");
6035 // Check that the specialization uses the same tag kind as the
6036 // original template.
6037 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
6038 assert(Kind != TTK_Enum && "Invalid enum tag in class template spec!");
6039 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
6040 Kind, TUK == TUK_Definition, KWLoc,
6041 *ClassTemplate->getIdentifier())) {
6042 Diag(KWLoc, diag::err_use_with_wrong_tag)
6044 << FixItHint::CreateReplacement(KWLoc,
6045 ClassTemplate->getTemplatedDecl()->getKindName());
6046 Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
6047 diag::note_previous_use);
6048 Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
6051 // Translate the parser's template argument list in our AST format.
6052 TemplateArgumentListInfo TemplateArgs =
6053 makeTemplateArgumentListInfo(*this, TemplateId);
6055 // Check for unexpanded parameter packs in any of the template arguments.
6056 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
6057 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
6058 UPPC_PartialSpecialization))
6061 // Check that the template argument list is well-formed for this
6063 SmallVector<TemplateArgument, 4> Converted;
6064 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
6065 TemplateArgs, false, Converted))
6068 // Find the class template (partial) specialization declaration that
6069 // corresponds to these arguments.
6070 if (isPartialSpecialization) {
6071 if (CheckTemplatePartialSpecializationArgs(
6072 *this, TemplateNameLoc, ClassTemplate->getTemplateParameters(),
6073 TemplateArgs.size(), Converted))
6076 bool InstantiationDependent;
6077 if (!Name.isDependent() &&
6078 !TemplateSpecializationType::anyDependentTemplateArguments(
6079 TemplateArgs.getArgumentArray(),
6080 TemplateArgs.size(),
6081 InstantiationDependent)) {
6082 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
6083 << ClassTemplate->getDeclName();
6084 isPartialSpecialization = false;
6088 void *InsertPos = nullptr;
6089 ClassTemplateSpecializationDecl *PrevDecl = nullptr;
6091 if (isPartialSpecialization)
6092 // FIXME: Template parameter list matters, too
6093 PrevDecl = ClassTemplate->findPartialSpecialization(Converted, InsertPos);
6095 PrevDecl = ClassTemplate->findSpecialization(Converted, InsertPos);
6097 ClassTemplateSpecializationDecl *Specialization = nullptr;
6099 // Check whether we can declare a class template specialization in
6100 // the current scope.
6101 if (TUK != TUK_Friend &&
6102 CheckTemplateSpecializationScope(*this, ClassTemplate, PrevDecl,
6104 isPartialSpecialization))
6107 // The canonical type
6109 if (isPartialSpecialization) {
6110 // Build the canonical type that describes the converted template
6111 // arguments of the class template partial specialization.
6112 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
6113 CanonType = Context.getTemplateSpecializationType(CanonTemplate,
6117 if (Context.hasSameType(CanonType,
6118 ClassTemplate->getInjectedClassNameSpecialization())) {
6119 // C++ [temp.class.spec]p9b3:
6121 // -- The argument list of the specialization shall not be identical
6122 // to the implicit argument list of the primary template.
6123 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
6124 << /*class template*/0 << (TUK == TUK_Definition)
6125 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
6126 return CheckClassTemplate(S, TagSpec, TUK, KWLoc, SS,
6127 ClassTemplate->getIdentifier(),
6131 AS_none, /*ModulePrivateLoc=*/SourceLocation(),
6132 /*FriendLoc*/SourceLocation(),
6133 TemplateParameterLists.size() - 1,
6134 TemplateParameterLists.data());
6137 // Create a new class template partial specialization declaration node.
6138 ClassTemplatePartialSpecializationDecl *PrevPartial
6139 = cast_or_null<ClassTemplatePartialSpecializationDecl>(PrevDecl);
6140 ClassTemplatePartialSpecializationDecl *Partial
6141 = ClassTemplatePartialSpecializationDecl::Create(Context, Kind,
6142 ClassTemplate->getDeclContext(),
6143 KWLoc, TemplateNameLoc,
6151 SetNestedNameSpecifier(Partial, SS);
6152 if (TemplateParameterLists.size() > 1 && SS.isSet()) {
6153 Partial->setTemplateParameterListsInfo(Context,
6154 TemplateParameterLists.size() - 1,
6155 TemplateParameterLists.data());
6159 ClassTemplate->AddPartialSpecialization(Partial, InsertPos);
6160 Specialization = Partial;
6162 // If we are providing an explicit specialization of a member class
6163 // template specialization, make a note of that.
6164 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
6165 PrevPartial->setMemberSpecialization();
6167 // Check that all of the template parameters of the class template
6168 // partial specialization are deducible from the template
6169 // arguments. If not, this class template partial specialization
6170 // will never be used.
6171 llvm::SmallBitVector DeducibleParams(TemplateParams->size());
6172 MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
6173 TemplateParams->getDepth(),
6176 if (!DeducibleParams.all()) {
6177 unsigned NumNonDeducible = DeducibleParams.size()-DeducibleParams.count();
6178 Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible)
6179 << /*class template*/0 << (NumNonDeducible > 1)
6180 << SourceRange(TemplateNameLoc, RAngleLoc);
6181 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) {
6182 if (!DeducibleParams[I]) {
6183 NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I));
6184 if (Param->getDeclName())
6185 Diag(Param->getLocation(),
6186 diag::note_partial_spec_unused_parameter)
6187 << Param->getDeclName();
6189 Diag(Param->getLocation(),
6190 diag::note_partial_spec_unused_parameter)
6196 // Create a new class template specialization declaration node for
6197 // this explicit specialization or friend declaration.
6199 = ClassTemplateSpecializationDecl::Create(Context, Kind,
6200 ClassTemplate->getDeclContext(),
6201 KWLoc, TemplateNameLoc,
6206 SetNestedNameSpecifier(Specialization, SS);
6207 if (TemplateParameterLists.size() > 0) {
6208 Specialization->setTemplateParameterListsInfo(Context,
6209 TemplateParameterLists.size(),
6210 TemplateParameterLists.data());
6214 ClassTemplate->AddSpecialization(Specialization, InsertPos);
6216 CanonType = Context.getTypeDeclType(Specialization);
6219 // C++ [temp.expl.spec]p6:
6220 // If a template, a member template or the member of a class template is
6221 // explicitly specialized then that specialization shall be declared
6222 // before the first use of that specialization that would cause an implicit
6223 // instantiation to take place, in every translation unit in which such a
6224 // use occurs; no diagnostic is required.
6225 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
6227 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6228 // Is there any previous explicit specialization declaration?
6229 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
6236 SourceRange Range(TemplateNameLoc, RAngleLoc);
6237 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
6238 << Context.getTypeDeclType(Specialization) << Range;
6240 Diag(PrevDecl->getPointOfInstantiation(),
6241 diag::note_instantiation_required_here)
6242 << (PrevDecl->getTemplateSpecializationKind()
6243 != TSK_ImplicitInstantiation);
6248 // If this is not a friend, note that this is an explicit specialization.
6249 if (TUK != TUK_Friend)
6250 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
6252 // Check that this isn't a redefinition of this specialization.
6253 if (TUK == TUK_Definition) {
6254 if (RecordDecl *Def = Specialization->getDefinition()) {
6255 SourceRange Range(TemplateNameLoc, RAngleLoc);
6256 Diag(TemplateNameLoc, diag::err_redefinition)
6257 << Context.getTypeDeclType(Specialization) << Range;
6258 Diag(Def->getLocation(), diag::note_previous_definition);
6259 Specialization->setInvalidDecl();
6265 ProcessDeclAttributeList(S, Specialization, Attr);
6267 // Add alignment attributes if necessary; these attributes are checked when
6268 // the ASTContext lays out the structure.
6269 if (TUK == TUK_Definition) {
6270 AddAlignmentAttributesForRecord(Specialization);
6271 AddMsStructLayoutForRecord(Specialization);
6274 if (ModulePrivateLoc.isValid())
6275 Diag(Specialization->getLocation(), diag::err_module_private_specialization)
6276 << (isPartialSpecialization? 1 : 0)
6277 << FixItHint::CreateRemoval(ModulePrivateLoc);
6279 // Build the fully-sugared type for this class template
6280 // specialization as the user wrote in the specialization
6281 // itself. This means that we'll pretty-print the type retrieved
6282 // from the specialization's declaration the way that the user
6283 // actually wrote the specialization, rather than formatting the
6284 // name based on the "canonical" representation used to store the
6285 // template arguments in the specialization.
6286 TypeSourceInfo *WrittenTy
6287 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
6288 TemplateArgs, CanonType);
6289 if (TUK != TUK_Friend) {
6290 Specialization->setTypeAsWritten(WrittenTy);
6291 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
6294 // C++ [temp.expl.spec]p9:
6295 // A template explicit specialization is in the scope of the
6296 // namespace in which the template was defined.
6298 // We actually implement this paragraph where we set the semantic
6299 // context (in the creation of the ClassTemplateSpecializationDecl),
6300 // but we also maintain the lexical context where the actual
6301 // definition occurs.
6302 Specialization->setLexicalDeclContext(CurContext);
6304 // We may be starting the definition of this specialization.
6305 if (TUK == TUK_Definition)
6306 Specialization->startDefinition();
6308 if (TUK == TUK_Friend) {
6309 FriendDecl *Friend = FriendDecl::Create(Context, CurContext,
6313 Friend->setAccess(AS_public);
6314 CurContext->addDecl(Friend);
6316 // Add the specialization into its lexical context, so that it can
6317 // be seen when iterating through the list of declarations in that
6318 // context. However, specializations are not found by name lookup.
6319 CurContext->addDecl(Specialization);
6321 return Specialization;
6324 Decl *Sema::ActOnTemplateDeclarator(Scope *S,
6325 MultiTemplateParamsArg TemplateParameterLists,
6327 Decl *NewDecl = HandleDeclarator(S, D, TemplateParameterLists);
6328 ActOnDocumentableDecl(NewDecl);
6332 Decl *Sema::ActOnStartOfFunctionTemplateDef(Scope *FnBodyScope,
6333 MultiTemplateParamsArg TemplateParameterLists,
6335 assert(getCurFunctionDecl() == nullptr && "Function parsing confused");
6336 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
6338 if (FTI.hasPrototype) {
6339 // FIXME: Diagnose arguments without names in C.
6342 Scope *ParentScope = FnBodyScope->getParent();
6344 D.setFunctionDefinitionKind(FDK_Definition);
6345 Decl *DP = HandleDeclarator(ParentScope, D,
6346 TemplateParameterLists);
6347 return ActOnStartOfFunctionDef(FnBodyScope, DP);
6350 /// \brief Strips various properties off an implicit instantiation
6351 /// that has just been explicitly specialized.
6352 static void StripImplicitInstantiation(NamedDecl *D) {
6355 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
6356 FD->setInlineSpecified(false);
6358 for (auto I : FD->params())
6363 /// \brief Compute the diagnostic location for an explicit instantiation
6364 // declaration or definition.
6365 static SourceLocation DiagLocForExplicitInstantiation(
6366 NamedDecl* D, SourceLocation PointOfInstantiation) {
6367 // Explicit instantiations following a specialization have no effect and
6368 // hence no PointOfInstantiation. In that case, walk decl backwards
6369 // until a valid name loc is found.
6370 SourceLocation PrevDiagLoc = PointOfInstantiation;
6371 for (Decl *Prev = D; Prev && !PrevDiagLoc.isValid();
6372 Prev = Prev->getPreviousDecl()) {
6373 PrevDiagLoc = Prev->getLocation();
6375 assert(PrevDiagLoc.isValid() &&
6376 "Explicit instantiation without point of instantiation?");
6380 /// \brief Diagnose cases where we have an explicit template specialization
6381 /// before/after an explicit template instantiation, producing diagnostics
6382 /// for those cases where they are required and determining whether the
6383 /// new specialization/instantiation will have any effect.
6385 /// \param NewLoc the location of the new explicit specialization or
6388 /// \param NewTSK the kind of the new explicit specialization or instantiation.
6390 /// \param PrevDecl the previous declaration of the entity.
6392 /// \param PrevTSK the kind of the old explicit specialization or instantiatin.
6394 /// \param PrevPointOfInstantiation if valid, indicates where the previus
6395 /// declaration was instantiated (either implicitly or explicitly).
6397 /// \param HasNoEffect will be set to true to indicate that the new
6398 /// specialization or instantiation has no effect and should be ignored.
6400 /// \returns true if there was an error that should prevent the introduction of
6401 /// the new declaration into the AST, false otherwise.
6403 Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc,
6404 TemplateSpecializationKind NewTSK,
6405 NamedDecl *PrevDecl,
6406 TemplateSpecializationKind PrevTSK,
6407 SourceLocation PrevPointOfInstantiation,
6408 bool &HasNoEffect) {
6409 HasNoEffect = false;
6412 case TSK_Undeclared:
6413 case TSK_ImplicitInstantiation:
6415 (PrevTSK == TSK_Undeclared || PrevTSK == TSK_ImplicitInstantiation) &&
6416 "previous declaration must be implicit!");
6419 case TSK_ExplicitSpecialization:
6421 case TSK_Undeclared:
6422 case TSK_ExplicitSpecialization:
6423 // Okay, we're just specializing something that is either already
6424 // explicitly specialized or has merely been mentioned without any
6428 case TSK_ImplicitInstantiation:
6429 if (PrevPointOfInstantiation.isInvalid()) {
6430 // The declaration itself has not actually been instantiated, so it is
6431 // still okay to specialize it.
6432 StripImplicitInstantiation(PrevDecl);
6437 case TSK_ExplicitInstantiationDeclaration:
6438 case TSK_ExplicitInstantiationDefinition:
6439 assert((PrevTSK == TSK_ImplicitInstantiation ||
6440 PrevPointOfInstantiation.isValid()) &&
6441 "Explicit instantiation without point of instantiation?");
6443 // C++ [temp.expl.spec]p6:
6444 // If a template, a member template or the member of a class template
6445 // is explicitly specialized then that specialization shall be declared
6446 // before the first use of that specialization that would cause an
6447 // implicit instantiation to take place, in every translation unit in
6448 // which such a use occurs; no diagnostic is required.
6449 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6450 // Is there any previous explicit specialization declaration?
6451 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization)
6455 Diag(NewLoc, diag::err_specialization_after_instantiation)
6457 Diag(PrevPointOfInstantiation, diag::note_instantiation_required_here)
6458 << (PrevTSK != TSK_ImplicitInstantiation);
6463 case TSK_ExplicitInstantiationDeclaration:
6465 case TSK_ExplicitInstantiationDeclaration:
6466 // This explicit instantiation declaration is redundant (that's okay).
6470 case TSK_Undeclared:
6471 case TSK_ImplicitInstantiation:
6472 // We're explicitly instantiating something that may have already been
6473 // implicitly instantiated; that's fine.
6476 case TSK_ExplicitSpecialization:
6477 // C++0x [temp.explicit]p4:
6478 // For a given set of template parameters, if an explicit instantiation
6479 // of a template appears after a declaration of an explicit
6480 // specialization for that template, the explicit instantiation has no
6485 case TSK_ExplicitInstantiationDefinition:
6486 // C++0x [temp.explicit]p10:
6487 // If an entity is the subject of both an explicit instantiation
6488 // declaration and an explicit instantiation definition in the same
6489 // translation unit, the definition shall follow the declaration.
6491 diag::err_explicit_instantiation_declaration_after_definition);
6493 // Explicit instantiations following a specialization have no effect and
6494 // hence no PrevPointOfInstantiation. In that case, walk decl backwards
6495 // until a valid name loc is found.
6496 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
6497 diag::note_explicit_instantiation_definition_here);
6502 case TSK_ExplicitInstantiationDefinition:
6504 case TSK_Undeclared:
6505 case TSK_ImplicitInstantiation:
6506 // We're explicitly instantiating something that may have already been
6507 // implicitly instantiated; that's fine.
6510 case TSK_ExplicitSpecialization:
6511 // C++ DR 259, C++0x [temp.explicit]p4:
6512 // For a given set of template parameters, if an explicit
6513 // instantiation of a template appears after a declaration of
6514 // an explicit specialization for that template, the explicit
6515 // instantiation has no effect.
6517 // In C++98/03 mode, we only give an extension warning here, because it
6518 // is not harmful to try to explicitly instantiate something that
6519 // has been explicitly specialized.
6520 Diag(NewLoc, getLangOpts().CPlusPlus11 ?
6521 diag::warn_cxx98_compat_explicit_instantiation_after_specialization :
6522 diag::ext_explicit_instantiation_after_specialization)
6524 Diag(PrevDecl->getLocation(),
6525 diag::note_previous_template_specialization);
6529 case TSK_ExplicitInstantiationDeclaration:
6530 // We're explicity instantiating a definition for something for which we
6531 // were previously asked to suppress instantiations. That's fine.
6533 // C++0x [temp.explicit]p4:
6534 // For a given set of template parameters, if an explicit instantiation
6535 // of a template appears after a declaration of an explicit
6536 // specialization for that template, the explicit instantiation has no
6538 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6539 // Is there any previous explicit specialization declaration?
6540 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
6548 case TSK_ExplicitInstantiationDefinition:
6549 // C++0x [temp.spec]p5:
6550 // For a given template and a given set of template-arguments,
6551 // - an explicit instantiation definition shall appear at most once
6554 // MSVCCompat: MSVC silently ignores duplicate explicit instantiations.
6555 Diag(NewLoc, (getLangOpts().MSVCCompat)
6556 ? diag::ext_explicit_instantiation_duplicate
6557 : diag::err_explicit_instantiation_duplicate)
6559 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
6560 diag::note_previous_explicit_instantiation);
6566 llvm_unreachable("Missing specialization/instantiation case?");
6569 /// \brief Perform semantic analysis for the given dependent function
6570 /// template specialization.
6572 /// The only possible way to get a dependent function template specialization
6573 /// is with a friend declaration, like so:
6576 /// template \<class T> void foo(T);
6577 /// template \<class T> class A {
6578 /// friend void foo<>(T);
6582 /// There really isn't any useful analysis we can do here, so we
6583 /// just store the information.
6585 Sema::CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD,
6586 const TemplateArgumentListInfo &ExplicitTemplateArgs,
6587 LookupResult &Previous) {
6588 // Remove anything from Previous that isn't a function template in
6589 // the correct context.
6590 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
6591 LookupResult::Filter F = Previous.makeFilter();
6592 while (F.hasNext()) {
6593 NamedDecl *D = F.next()->getUnderlyingDecl();
6594 if (!isa<FunctionTemplateDecl>(D) ||
6595 !FDLookupContext->InEnclosingNamespaceSetOf(
6596 D->getDeclContext()->getRedeclContext()))
6601 // Should this be diagnosed here?
6602 if (Previous.empty()) return true;
6604 FD->setDependentTemplateSpecialization(Context, Previous.asUnresolvedSet(),
6605 ExplicitTemplateArgs);
6609 /// \brief Perform semantic analysis for the given function template
6612 /// This routine performs all of the semantic analysis required for an
6613 /// explicit function template specialization. On successful completion,
6614 /// the function declaration \p FD will become a function template
6617 /// \param FD the function declaration, which will be updated to become a
6618 /// function template specialization.
6620 /// \param ExplicitTemplateArgs the explicitly-provided template arguments,
6621 /// if any. Note that this may be valid info even when 0 arguments are
6622 /// explicitly provided as in, e.g., \c void sort<>(char*, char*);
6623 /// as it anyway contains info on the angle brackets locations.
6625 /// \param Previous the set of declarations that may be specialized by
6626 /// this function specialization.
6627 bool Sema::CheckFunctionTemplateSpecialization(
6628 FunctionDecl *FD, TemplateArgumentListInfo *ExplicitTemplateArgs,
6629 LookupResult &Previous) {
6630 // The set of function template specializations that could match this
6631 // explicit function template specialization.
6632 UnresolvedSet<8> Candidates;
6633 TemplateSpecCandidateSet FailedCandidates(FD->getLocation());
6635 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
6636 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
6638 NamedDecl *Ovl = (*I)->getUnderlyingDecl();
6639 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Ovl)) {
6640 // Only consider templates found within the same semantic lookup scope as
6642 if (!FDLookupContext->InEnclosingNamespaceSetOf(
6643 Ovl->getDeclContext()->getRedeclContext()))
6646 // When matching a constexpr member function template specialization
6647 // against the primary template, we don't yet know whether the
6648 // specialization has an implicit 'const' (because we don't know whether
6649 // it will be a static member function until we know which template it
6650 // specializes), so adjust it now assuming it specializes this template.
6651 QualType FT = FD->getType();
6652 if (FD->isConstexpr()) {
6653 CXXMethodDecl *OldMD =
6654 dyn_cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl());
6655 if (OldMD && OldMD->isConst()) {
6656 const FunctionProtoType *FPT = FT->castAs<FunctionProtoType>();
6657 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
6658 EPI.TypeQuals |= Qualifiers::Const;
6659 FT = Context.getFunctionType(FPT->getReturnType(),
6660 FPT->getParamTypes(), EPI);
6664 // C++ [temp.expl.spec]p11:
6665 // A trailing template-argument can be left unspecified in the
6666 // template-id naming an explicit function template specialization
6667 // provided it can be deduced from the function argument type.
6668 // Perform template argument deduction to determine whether we may be
6669 // specializing this template.
6670 // FIXME: It is somewhat wasteful to build
6671 TemplateDeductionInfo Info(FailedCandidates.getLocation());
6672 FunctionDecl *Specialization = nullptr;
6673 if (TemplateDeductionResult TDK = DeduceTemplateArguments(
6674 cast<FunctionTemplateDecl>(FunTmpl->getFirstDecl()),
6675 ExplicitTemplateArgs, FT, Specialization, Info)) {
6676 // Template argument deduction failed; record why it failed, so
6677 // that we can provide nifty diagnostics.
6678 FailedCandidates.addCandidate()
6679 .set(FunTmpl->getTemplatedDecl(),
6680 MakeDeductionFailureInfo(Context, TDK, Info));
6685 // Record this candidate.
6686 Candidates.addDecl(Specialization, I.getAccess());
6690 // Find the most specialized function template.
6691 UnresolvedSetIterator Result = getMostSpecialized(
6692 Candidates.begin(), Candidates.end(), FailedCandidates,
6694 PDiag(diag::err_function_template_spec_no_match) << FD->getDeclName(),
6695 PDiag(diag::err_function_template_spec_ambiguous)
6696 << FD->getDeclName() << (ExplicitTemplateArgs != nullptr),
6697 PDiag(diag::note_function_template_spec_matched));
6699 if (Result == Candidates.end())
6702 // Ignore access information; it doesn't figure into redeclaration checking.
6703 FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
6705 FunctionTemplateSpecializationInfo *SpecInfo
6706 = Specialization->getTemplateSpecializationInfo();
6707 assert(SpecInfo && "Function template specialization info missing?");
6709 // Note: do not overwrite location info if previous template
6710 // specialization kind was explicit.
6711 TemplateSpecializationKind TSK = SpecInfo->getTemplateSpecializationKind();
6712 if (TSK == TSK_Undeclared || TSK == TSK_ImplicitInstantiation) {
6713 Specialization->setLocation(FD->getLocation());
6714 // C++11 [dcl.constexpr]p1: An explicit specialization of a constexpr
6715 // function can differ from the template declaration with respect to
6716 // the constexpr specifier.
6717 Specialization->setConstexpr(FD->isConstexpr());
6720 // FIXME: Check if the prior specialization has a point of instantiation.
6721 // If so, we have run afoul of .
6723 // If this is a friend declaration, then we're not really declaring
6724 // an explicit specialization.
6725 bool isFriend = (FD->getFriendObjectKind() != Decl::FOK_None);
6727 // Check the scope of this explicit specialization.
6729 CheckTemplateSpecializationScope(*this,
6730 Specialization->getPrimaryTemplate(),
6731 Specialization, FD->getLocation(),
6735 // C++ [temp.expl.spec]p6:
6736 // If a template, a member template or the member of a class template is
6737 // explicitly specialized then that specialization shall be declared
6738 // before the first use of that specialization that would cause an implicit
6739 // instantiation to take place, in every translation unit in which such a
6740 // use occurs; no diagnostic is required.
6741 bool HasNoEffect = false;
6743 CheckSpecializationInstantiationRedecl(FD->getLocation(),
6744 TSK_ExplicitSpecialization,
6746 SpecInfo->getTemplateSpecializationKind(),
6747 SpecInfo->getPointOfInstantiation(),
6751 // Mark the prior declaration as an explicit specialization, so that later
6752 // clients know that this is an explicit specialization.
6754 SpecInfo->setTemplateSpecializationKind(TSK_ExplicitSpecialization);
6755 MarkUnusedFileScopedDecl(Specialization);
6758 // Turn the given function declaration into a function template
6759 // specialization, with the template arguments from the previous
6761 // Take copies of (semantic and syntactic) template argument lists.
6762 const TemplateArgumentList* TemplArgs = new (Context)
6763 TemplateArgumentList(Specialization->getTemplateSpecializationArgs());
6764 FD->setFunctionTemplateSpecialization(Specialization->getPrimaryTemplate(),
6765 TemplArgs, /*InsertPos=*/nullptr,
6766 SpecInfo->getTemplateSpecializationKind(),
6767 ExplicitTemplateArgs);
6769 // The "previous declaration" for this function template specialization is
6770 // the prior function template specialization.
6772 Previous.addDecl(Specialization);
6776 /// \brief Perform semantic analysis for the given non-template member
6779 /// This routine performs all of the semantic analysis required for an
6780 /// explicit member function specialization. On successful completion,
6781 /// the function declaration \p FD will become a member function
6784 /// \param Member the member declaration, which will be updated to become a
6787 /// \param Previous the set of declarations, one of which may be specialized
6788 /// by this function specialization; the set will be modified to contain the
6789 /// redeclared member.
6791 Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
6792 assert(!isa<TemplateDecl>(Member) && "Only for non-template members");
6794 // Try to find the member we are instantiating.
6795 NamedDecl *Instantiation = nullptr;
6796 NamedDecl *InstantiatedFrom = nullptr;
6797 MemberSpecializationInfo *MSInfo = nullptr;
6799 if (Previous.empty()) {
6800 // Nowhere to look anyway.
6801 } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Member)) {
6802 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
6804 NamedDecl *D = (*I)->getUnderlyingDecl();
6805 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
6806 QualType Adjusted = Function->getType();
6807 if (!hasExplicitCallingConv(Adjusted))
6808 Adjusted = adjustCCAndNoReturn(Adjusted, Method->getType());
6809 if (Context.hasSameType(Adjusted, Method->getType())) {
6810 Instantiation = Method;
6811 InstantiatedFrom = Method->getInstantiatedFromMemberFunction();
6812 MSInfo = Method->getMemberSpecializationInfo();
6817 } else if (isa<VarDecl>(Member)) {
6819 if (Previous.isSingleResult() &&
6820 (PrevVar = dyn_cast<VarDecl>(Previous.getFoundDecl())))
6821 if (PrevVar->isStaticDataMember()) {
6822 Instantiation = PrevVar;
6823 InstantiatedFrom = PrevVar->getInstantiatedFromStaticDataMember();
6824 MSInfo = PrevVar->getMemberSpecializationInfo();
6826 } else if (isa<RecordDecl>(Member)) {
6827 CXXRecordDecl *PrevRecord;
6828 if (Previous.isSingleResult() &&
6829 (PrevRecord = dyn_cast<CXXRecordDecl>(Previous.getFoundDecl()))) {
6830 Instantiation = PrevRecord;
6831 InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass();
6832 MSInfo = PrevRecord->getMemberSpecializationInfo();
6834 } else if (isa<EnumDecl>(Member)) {
6836 if (Previous.isSingleResult() &&
6837 (PrevEnum = dyn_cast<EnumDecl>(Previous.getFoundDecl()))) {
6838 Instantiation = PrevEnum;
6839 InstantiatedFrom = PrevEnum->getInstantiatedFromMemberEnum();
6840 MSInfo = PrevEnum->getMemberSpecializationInfo();
6844 if (!Instantiation) {
6845 // There is no previous declaration that matches. Since member
6846 // specializations are always out-of-line, the caller will complain about
6847 // this mismatch later.
6851 // If this is a friend, just bail out here before we start turning
6852 // things into explicit specializations.
6853 if (Member->getFriendObjectKind() != Decl::FOK_None) {
6854 // Preserve instantiation information.
6855 if (InstantiatedFrom && isa<CXXMethodDecl>(Member)) {
6856 cast<CXXMethodDecl>(Member)->setInstantiationOfMemberFunction(
6857 cast<CXXMethodDecl>(InstantiatedFrom),
6858 cast<CXXMethodDecl>(Instantiation)->getTemplateSpecializationKind());
6859 } else if (InstantiatedFrom && isa<CXXRecordDecl>(Member)) {
6860 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
6861 cast<CXXRecordDecl>(InstantiatedFrom),
6862 cast<CXXRecordDecl>(Instantiation)->getTemplateSpecializationKind());
6866 Previous.addDecl(Instantiation);
6870 // Make sure that this is a specialization of a member.
6871 if (!InstantiatedFrom) {
6872 Diag(Member->getLocation(), diag::err_spec_member_not_instantiated)
6874 Diag(Instantiation->getLocation(), diag::note_specialized_decl);
6878 // C++ [temp.expl.spec]p6:
6879 // If a template, a member template or the member of a class template is
6880 // explicitly specialized then that specialization shall be declared
6881 // before the first use of that specialization that would cause an implicit
6882 // instantiation to take place, in every translation unit in which such a
6883 // use occurs; no diagnostic is required.
6884 assert(MSInfo && "Member specialization info missing?");
6886 bool HasNoEffect = false;
6887 if (CheckSpecializationInstantiationRedecl(Member->getLocation(),
6888 TSK_ExplicitSpecialization,
6890 MSInfo->getTemplateSpecializationKind(),
6891 MSInfo->getPointOfInstantiation(),
6895 // Check the scope of this explicit specialization.
6896 if (CheckTemplateSpecializationScope(*this,
6898 Instantiation, Member->getLocation(),
6902 // Note that this is an explicit instantiation of a member.
6903 // the original declaration to note that it is an explicit specialization
6904 // (if it was previously an implicit instantiation). This latter step
6905 // makes bookkeeping easier.
6906 if (isa<FunctionDecl>(Member)) {
6907 FunctionDecl *InstantiationFunction = cast<FunctionDecl>(Instantiation);
6908 if (InstantiationFunction->getTemplateSpecializationKind() ==
6909 TSK_ImplicitInstantiation) {
6910 InstantiationFunction->setTemplateSpecializationKind(
6911 TSK_ExplicitSpecialization);
6912 InstantiationFunction->setLocation(Member->getLocation());
6915 cast<FunctionDecl>(Member)->setInstantiationOfMemberFunction(
6916 cast<CXXMethodDecl>(InstantiatedFrom),
6917 TSK_ExplicitSpecialization);
6918 MarkUnusedFileScopedDecl(InstantiationFunction);
6919 } else if (isa<VarDecl>(Member)) {
6920 VarDecl *InstantiationVar = cast<VarDecl>(Instantiation);
6921 if (InstantiationVar->getTemplateSpecializationKind() ==
6922 TSK_ImplicitInstantiation) {
6923 InstantiationVar->setTemplateSpecializationKind(
6924 TSK_ExplicitSpecialization);
6925 InstantiationVar->setLocation(Member->getLocation());
6928 cast<VarDecl>(Member)->setInstantiationOfStaticDataMember(
6929 cast<VarDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
6930 MarkUnusedFileScopedDecl(InstantiationVar);
6931 } else if (isa<CXXRecordDecl>(Member)) {
6932 CXXRecordDecl *InstantiationClass = cast<CXXRecordDecl>(Instantiation);
6933 if (InstantiationClass->getTemplateSpecializationKind() ==
6934 TSK_ImplicitInstantiation) {
6935 InstantiationClass->setTemplateSpecializationKind(
6936 TSK_ExplicitSpecialization);
6937 InstantiationClass->setLocation(Member->getLocation());
6940 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
6941 cast<CXXRecordDecl>(InstantiatedFrom),
6942 TSK_ExplicitSpecialization);
6944 assert(isa<EnumDecl>(Member) && "Only member enums remain");
6945 EnumDecl *InstantiationEnum = cast<EnumDecl>(Instantiation);
6946 if (InstantiationEnum->getTemplateSpecializationKind() ==
6947 TSK_ImplicitInstantiation) {
6948 InstantiationEnum->setTemplateSpecializationKind(
6949 TSK_ExplicitSpecialization);
6950 InstantiationEnum->setLocation(Member->getLocation());
6953 cast<EnumDecl>(Member)->setInstantiationOfMemberEnum(
6954 cast<EnumDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
6957 // Save the caller the trouble of having to figure out which declaration
6958 // this specialization matches.
6960 Previous.addDecl(Instantiation);
6964 /// \brief Check the scope of an explicit instantiation.
6966 /// \returns true if a serious error occurs, false otherwise.
6967 static bool CheckExplicitInstantiationScope(Sema &S, NamedDecl *D,
6968 SourceLocation InstLoc,
6969 bool WasQualifiedName) {
6970 DeclContext *OrigContext= D->getDeclContext()->getEnclosingNamespaceContext();
6971 DeclContext *CurContext = S.CurContext->getRedeclContext();
6973 if (CurContext->isRecord()) {
6974 S.Diag(InstLoc, diag::err_explicit_instantiation_in_class)
6979 // C++11 [temp.explicit]p3:
6980 // An explicit instantiation shall appear in an enclosing namespace of its
6981 // template. If the name declared in the explicit instantiation is an
6982 // unqualified name, the explicit instantiation shall appear in the
6983 // namespace where its template is declared or, if that namespace is inline
6984 // (7.3.1), any namespace from its enclosing namespace set.
6986 // This is DR275, which we do not retroactively apply to C++98/03.
6987 if (WasQualifiedName) {
6988 if (CurContext->Encloses(OrigContext))
6991 if (CurContext->InEnclosingNamespaceSetOf(OrigContext))
6995 if (NamespaceDecl *NS = dyn_cast<NamespaceDecl>(OrigContext)) {
6996 if (WasQualifiedName)
6998 S.getLangOpts().CPlusPlus11?
6999 diag::err_explicit_instantiation_out_of_scope :
7000 diag::warn_explicit_instantiation_out_of_scope_0x)
7004 S.getLangOpts().CPlusPlus11?
7005 diag::err_explicit_instantiation_unqualified_wrong_namespace :
7006 diag::warn_explicit_instantiation_unqualified_wrong_namespace_0x)
7010 S.getLangOpts().CPlusPlus11?
7011 diag::err_explicit_instantiation_must_be_global :
7012 diag::warn_explicit_instantiation_must_be_global_0x)
7014 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here);
7018 /// \brief Determine whether the given scope specifier has a template-id in it.
7019 static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec &SS) {
7023 // C++11 [temp.explicit]p3:
7024 // If the explicit instantiation is for a member function, a member class
7025 // or a static data member of a class template specialization, the name of
7026 // the class template specialization in the qualified-id for the member
7027 // name shall be a simple-template-id.
7029 // C++98 has the same restriction, just worded differently.
7030 for (NestedNameSpecifier *NNS = SS.getScopeRep(); NNS;
7031 NNS = NNS->getPrefix())
7032 if (const Type *T = NNS->getAsType())
7033 if (isa<TemplateSpecializationType>(T))
7039 // Explicit instantiation of a class template specialization
7041 Sema::ActOnExplicitInstantiation(Scope *S,
7042 SourceLocation ExternLoc,
7043 SourceLocation TemplateLoc,
7045 SourceLocation KWLoc,
7046 const CXXScopeSpec &SS,
7047 TemplateTy TemplateD,
7048 SourceLocation TemplateNameLoc,
7049 SourceLocation LAngleLoc,
7050 ASTTemplateArgsPtr TemplateArgsIn,
7051 SourceLocation RAngleLoc,
7052 AttributeList *Attr) {
7053 // Find the class template we're specializing
7054 TemplateName Name = TemplateD.get();
7055 TemplateDecl *TD = Name.getAsTemplateDecl();
7056 // Check that the specialization uses the same tag kind as the
7057 // original template.
7058 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
7059 assert(Kind != TTK_Enum &&
7060 "Invalid enum tag in class template explicit instantiation!");
7062 if (isa<TypeAliasTemplateDecl>(TD)) {
7063 Diag(KWLoc, diag::err_tag_reference_non_tag) << Kind;
7064 Diag(TD->getTemplatedDecl()->getLocation(),
7065 diag::note_previous_use);
7069 ClassTemplateDecl *ClassTemplate = cast<ClassTemplateDecl>(TD);
7071 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
7072 Kind, /*isDefinition*/false, KWLoc,
7073 *ClassTemplate->getIdentifier())) {
7074 Diag(KWLoc, diag::err_use_with_wrong_tag)
7076 << FixItHint::CreateReplacement(KWLoc,
7077 ClassTemplate->getTemplatedDecl()->getKindName());
7078 Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
7079 diag::note_previous_use);
7080 Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
7083 // C++0x [temp.explicit]p2:
7084 // There are two forms of explicit instantiation: an explicit instantiation
7085 // definition and an explicit instantiation declaration. An explicit
7086 // instantiation declaration begins with the extern keyword. [...]
7087 TemplateSpecializationKind TSK
7088 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
7089 : TSK_ExplicitInstantiationDeclaration;
7091 // Translate the parser's template argument list in our AST format.
7092 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
7093 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
7095 // Check that the template argument list is well-formed for this
7097 SmallVector<TemplateArgument, 4> Converted;
7098 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
7099 TemplateArgs, false, Converted))
7102 // Find the class template specialization declaration that
7103 // corresponds to these arguments.
7104 void *InsertPos = nullptr;
7105 ClassTemplateSpecializationDecl *PrevDecl
7106 = ClassTemplate->findSpecialization(Converted, InsertPos);
7108 TemplateSpecializationKind PrevDecl_TSK
7109 = PrevDecl ? PrevDecl->getTemplateSpecializationKind() : TSK_Undeclared;
7111 // C++0x [temp.explicit]p2:
7112 // [...] An explicit instantiation shall appear in an enclosing
7113 // namespace of its template. [...]
7115 // This is C++ DR 275.
7116 if (CheckExplicitInstantiationScope(*this, ClassTemplate, TemplateNameLoc,
7120 ClassTemplateSpecializationDecl *Specialization = nullptr;
7122 bool HasNoEffect = false;
7124 if (CheckSpecializationInstantiationRedecl(TemplateNameLoc, TSK,
7125 PrevDecl, PrevDecl_TSK,
7126 PrevDecl->getPointOfInstantiation(),
7130 // Even though HasNoEffect == true means that this explicit instantiation
7131 // has no effect on semantics, we go on to put its syntax in the AST.
7133 if (PrevDecl_TSK == TSK_ImplicitInstantiation ||
7134 PrevDecl_TSK == TSK_Undeclared) {
7135 // Since the only prior class template specialization with these
7136 // arguments was referenced but not declared, reuse that
7137 // declaration node as our own, updating the source location
7138 // for the template name to reflect our new declaration.
7139 // (Other source locations will be updated later.)
7140 Specialization = PrevDecl;
7141 Specialization->setLocation(TemplateNameLoc);
7146 if (!Specialization) {
7147 // Create a new class template specialization declaration node for
7148 // this explicit specialization.
7150 = ClassTemplateSpecializationDecl::Create(Context, Kind,
7151 ClassTemplate->getDeclContext(),
7152 KWLoc, TemplateNameLoc,
7157 SetNestedNameSpecifier(Specialization, SS);
7159 if (!HasNoEffect && !PrevDecl) {
7160 // Insert the new specialization.
7161 ClassTemplate->AddSpecialization(Specialization, InsertPos);
7165 // Build the fully-sugared type for this explicit instantiation as
7166 // the user wrote in the explicit instantiation itself. This means
7167 // that we'll pretty-print the type retrieved from the
7168 // specialization's declaration the way that the user actually wrote
7169 // the explicit instantiation, rather than formatting the name based
7170 // on the "canonical" representation used to store the template
7171 // arguments in the specialization.
7172 TypeSourceInfo *WrittenTy
7173 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
7175 Context.getTypeDeclType(Specialization));
7176 Specialization->setTypeAsWritten(WrittenTy);
7178 // Set source locations for keywords.
7179 Specialization->setExternLoc(ExternLoc);
7180 Specialization->setTemplateKeywordLoc(TemplateLoc);
7181 Specialization->setRBraceLoc(SourceLocation());
7184 ProcessDeclAttributeList(S, Specialization, Attr);
7186 // Add the explicit instantiation into its lexical context. However,
7187 // since explicit instantiations are never found by name lookup, we
7188 // just put it into the declaration context directly.
7189 Specialization->setLexicalDeclContext(CurContext);
7190 CurContext->addDecl(Specialization);
7192 // Syntax is now OK, so return if it has no other effect on semantics.
7194 // Set the template specialization kind.
7195 Specialization->setTemplateSpecializationKind(TSK);
7196 return Specialization;
7199 // C++ [temp.explicit]p3:
7200 // A definition of a class template or class member template
7201 // shall be in scope at the point of the explicit instantiation of
7202 // the class template or class member template.
7204 // This check comes when we actually try to perform the
7206 ClassTemplateSpecializationDecl *Def
7207 = cast_or_null<ClassTemplateSpecializationDecl>(
7208 Specialization->getDefinition());
7210 InstantiateClassTemplateSpecialization(TemplateNameLoc, Specialization, TSK);
7211 else if (TSK == TSK_ExplicitInstantiationDefinition) {
7212 MarkVTableUsed(TemplateNameLoc, Specialization, true);
7213 Specialization->setPointOfInstantiation(Def->getPointOfInstantiation());
7216 // Instantiate the members of this class template specialization.
7217 Def = cast_or_null<ClassTemplateSpecializationDecl>(
7218 Specialization->getDefinition());
7220 TemplateSpecializationKind Old_TSK = Def->getTemplateSpecializationKind();
7222 // Fix a TSK_ExplicitInstantiationDeclaration followed by a
7223 // TSK_ExplicitInstantiationDefinition
7224 if (Old_TSK == TSK_ExplicitInstantiationDeclaration &&
7225 TSK == TSK_ExplicitInstantiationDefinition)
7226 // FIXME: Need to notify the ASTMutationListener that we did this.
7227 Def->setTemplateSpecializationKind(TSK);
7229 InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK);
7232 // Set the template specialization kind.
7233 Specialization->setTemplateSpecializationKind(TSK);
7234 return Specialization;
7237 // Explicit instantiation of a member class of a class template.
7239 Sema::ActOnExplicitInstantiation(Scope *S,
7240 SourceLocation ExternLoc,
7241 SourceLocation TemplateLoc,
7243 SourceLocation KWLoc,
7245 IdentifierInfo *Name,
7246 SourceLocation NameLoc,
7247 AttributeList *Attr) {
7250 bool IsDependent = false;
7251 Decl *TagD = ActOnTag(S, TagSpec, Sema::TUK_Reference,
7252 KWLoc, SS, Name, NameLoc, Attr, AS_none,
7253 /*ModulePrivateLoc=*/SourceLocation(),
7254 MultiTemplateParamsArg(), Owned, IsDependent,
7255 SourceLocation(), false, TypeResult(),
7256 /*IsTypeSpecifier*/false);
7257 assert(!IsDependent && "explicit instantiation of dependent name not yet handled");
7262 TagDecl *Tag = cast<TagDecl>(TagD);
7263 assert(!Tag->isEnum() && "shouldn't see enumerations here");
7265 if (Tag->isInvalidDecl())
7268 CXXRecordDecl *Record = cast<CXXRecordDecl>(Tag);
7269 CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass();
7271 Diag(TemplateLoc, diag::err_explicit_instantiation_nontemplate_type)
7272 << Context.getTypeDeclType(Record);
7273 Diag(Record->getLocation(), diag::note_nontemplate_decl_here);
7277 // C++0x [temp.explicit]p2:
7278 // If the explicit instantiation is for a class or member class, the
7279 // elaborated-type-specifier in the declaration shall include a
7280 // simple-template-id.
7282 // C++98 has the same restriction, just worded differently.
7283 if (!ScopeSpecifierHasTemplateId(SS))
7284 Diag(TemplateLoc, diag::ext_explicit_instantiation_without_qualified_id)
7285 << Record << SS.getRange();
7287 // C++0x [temp.explicit]p2:
7288 // There are two forms of explicit instantiation: an explicit instantiation
7289 // definition and an explicit instantiation declaration. An explicit
7290 // instantiation declaration begins with the extern keyword. [...]
7291 TemplateSpecializationKind TSK
7292 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
7293 : TSK_ExplicitInstantiationDeclaration;
7295 // C++0x [temp.explicit]p2:
7296 // [...] An explicit instantiation shall appear in an enclosing
7297 // namespace of its template. [...]
7299 // This is C++ DR 275.
7300 CheckExplicitInstantiationScope(*this, Record, NameLoc, true);
7302 // Verify that it is okay to explicitly instantiate here.
7303 CXXRecordDecl *PrevDecl
7304 = cast_or_null<CXXRecordDecl>(Record->getPreviousDecl());
7305 if (!PrevDecl && Record->getDefinition())
7308 MemberSpecializationInfo *MSInfo = PrevDecl->getMemberSpecializationInfo();
7309 bool HasNoEffect = false;
7310 assert(MSInfo && "No member specialization information?");
7311 if (CheckSpecializationInstantiationRedecl(TemplateLoc, TSK,
7313 MSInfo->getTemplateSpecializationKind(),
7314 MSInfo->getPointOfInstantiation(),
7321 CXXRecordDecl *RecordDef
7322 = cast_or_null<CXXRecordDecl>(Record->getDefinition());
7324 // C++ [temp.explicit]p3:
7325 // A definition of a member class of a class template shall be in scope
7326 // at the point of an explicit instantiation of the member class.
7328 = cast_or_null<CXXRecordDecl>(Pattern->getDefinition());
7330 Diag(TemplateLoc, diag::err_explicit_instantiation_undefined_member)
7331 << 0 << Record->getDeclName() << Record->getDeclContext();
7332 Diag(Pattern->getLocation(), diag::note_forward_declaration)
7336 if (InstantiateClass(NameLoc, Record, Def,
7337 getTemplateInstantiationArgs(Record),
7341 RecordDef = cast_or_null<CXXRecordDecl>(Record->getDefinition());
7347 // Instantiate all of the members of the class.
7348 InstantiateClassMembers(NameLoc, RecordDef,
7349 getTemplateInstantiationArgs(Record), TSK);
7351 if (TSK == TSK_ExplicitInstantiationDefinition)
7352 MarkVTableUsed(NameLoc, RecordDef, true);
7354 // FIXME: We don't have any representation for explicit instantiations of
7355 // member classes. Such a representation is not needed for compilation, but it
7356 // should be available for clients that want to see all of the declarations in
7361 DeclResult Sema::ActOnExplicitInstantiation(Scope *S,
7362 SourceLocation ExternLoc,
7363 SourceLocation TemplateLoc,
7365 // Explicit instantiations always require a name.
7366 // TODO: check if/when DNInfo should replace Name.
7367 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
7368 DeclarationName Name = NameInfo.getName();
7370 if (!D.isInvalidType())
7371 Diag(D.getDeclSpec().getLocStart(),
7372 diag::err_explicit_instantiation_requires_name)
7373 << D.getDeclSpec().getSourceRange()
7374 << D.getSourceRange();
7379 // The scope passed in may not be a decl scope. Zip up the scope tree until
7380 // we find one that is.
7381 while ((S->getFlags() & Scope::DeclScope) == 0 ||
7382 (S->getFlags() & Scope::TemplateParamScope) != 0)
7385 // Determine the type of the declaration.
7386 TypeSourceInfo *T = GetTypeForDeclarator(D, S);
7387 QualType R = T->getType();
7392 // A storage-class-specifier shall not be specified in [...] an explicit
7393 // instantiation (14.7.2) directive.
7394 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
7395 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_of_typedef)
7398 } else if (D.getDeclSpec().getStorageClassSpec()
7399 != DeclSpec::SCS_unspecified) {
7400 // Complain about then remove the storage class specifier.
7401 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_storage_class)
7402 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
7404 D.getMutableDeclSpec().ClearStorageClassSpecs();
7407 // C++0x [temp.explicit]p1:
7408 // [...] An explicit instantiation of a function template shall not use the
7409 // inline or constexpr specifiers.
7410 // Presumably, this also applies to member functions of class templates as
7412 if (D.getDeclSpec().isInlineSpecified())
7413 Diag(D.getDeclSpec().getInlineSpecLoc(),
7414 getLangOpts().CPlusPlus11 ?
7415 diag::err_explicit_instantiation_inline :
7416 diag::warn_explicit_instantiation_inline_0x)
7417 << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
7418 if (D.getDeclSpec().isConstexprSpecified() && R->isFunctionType())
7419 // FIXME: Add a fix-it to remove the 'constexpr' and add a 'const' if one is
7420 // not already specified.
7421 Diag(D.getDeclSpec().getConstexprSpecLoc(),
7422 diag::err_explicit_instantiation_constexpr);
7424 // C++0x [temp.explicit]p2:
7425 // There are two forms of explicit instantiation: an explicit instantiation
7426 // definition and an explicit instantiation declaration. An explicit
7427 // instantiation declaration begins with the extern keyword. [...]
7428 TemplateSpecializationKind TSK
7429 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
7430 : TSK_ExplicitInstantiationDeclaration;
7432 LookupResult Previous(*this, NameInfo, LookupOrdinaryName);
7433 LookupParsedName(Previous, S, &D.getCXXScopeSpec());
7435 if (!R->isFunctionType()) {
7436 // C++ [temp.explicit]p1:
7437 // A [...] static data member of a class template can be explicitly
7438 // instantiated from the member definition associated with its class
7440 // C++1y [temp.explicit]p1:
7441 // A [...] variable [...] template specialization can be explicitly
7442 // instantiated from its template.
7443 if (Previous.isAmbiguous())
7446 VarDecl *Prev = Previous.getAsSingle<VarDecl>();
7447 VarTemplateDecl *PrevTemplate = Previous.getAsSingle<VarTemplateDecl>();
7449 if (!PrevTemplate) {
7450 if (!Prev || !Prev->isStaticDataMember()) {
7451 // We expect to see a data data member here.
7452 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_not_known)
7454 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
7456 Diag((*P)->getLocation(), diag::note_explicit_instantiation_here);
7460 if (!Prev->getInstantiatedFromStaticDataMember()) {
7461 // FIXME: Check for explicit specialization?
7462 Diag(D.getIdentifierLoc(),
7463 diag::err_explicit_instantiation_data_member_not_instantiated)
7465 Diag(Prev->getLocation(), diag::note_explicit_instantiation_here);
7466 // FIXME: Can we provide a note showing where this was declared?
7470 // Explicitly instantiate a variable template.
7472 // C++1y [dcl.spec.auto]p6:
7473 // ... A program that uses auto or decltype(auto) in a context not
7474 // explicitly allowed in this section is ill-formed.
7476 // This includes auto-typed variable template instantiations.
7477 if (R->isUndeducedType()) {
7478 Diag(T->getTypeLoc().getLocStart(),
7479 diag::err_auto_not_allowed_var_inst);
7483 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId) {
7484 // C++1y [temp.explicit]p3:
7485 // If the explicit instantiation is for a variable, the unqualified-id
7486 // in the declaration shall be a template-id.
7487 Diag(D.getIdentifierLoc(),
7488 diag::err_explicit_instantiation_without_template_id)
7490 Diag(PrevTemplate->getLocation(),
7491 diag::note_explicit_instantiation_here);
7495 // Translate the parser's template argument list into our AST format.
7496 TemplateArgumentListInfo TemplateArgs =
7497 makeTemplateArgumentListInfo(*this, *D.getName().TemplateId);
7499 DeclResult Res = CheckVarTemplateId(PrevTemplate, TemplateLoc,
7500 D.getIdentifierLoc(), TemplateArgs);
7501 if (Res.isInvalid())
7504 // Ignore access control bits, we don't need them for redeclaration
7506 Prev = cast<VarDecl>(Res.get());
7509 // C++0x [temp.explicit]p2:
7510 // If the explicit instantiation is for a member function, a member class
7511 // or a static data member of a class template specialization, the name of
7512 // the class template specialization in the qualified-id for the member
7513 // name shall be a simple-template-id.
7515 // C++98 has the same restriction, just worded differently.
7517 // This does not apply to variable template specializations, where the
7518 // template-id is in the unqualified-id instead.
7519 if (!ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()) && !PrevTemplate)
7520 Diag(D.getIdentifierLoc(),
7521 diag::ext_explicit_instantiation_without_qualified_id)
7522 << Prev << D.getCXXScopeSpec().getRange();
7524 // Check the scope of this explicit instantiation.
7525 CheckExplicitInstantiationScope(*this, Prev, D.getIdentifierLoc(), true);
7527 // Verify that it is okay to explicitly instantiate here.
7528 TemplateSpecializationKind PrevTSK = Prev->getTemplateSpecializationKind();
7529 SourceLocation POI = Prev->getPointOfInstantiation();
7530 bool HasNoEffect = false;
7531 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, Prev,
7532 PrevTSK, POI, HasNoEffect))
7536 // Instantiate static data member or variable template.
7538 Prev->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
7540 // Merge attributes.
7541 if (AttributeList *Attr = D.getDeclSpec().getAttributes().getList())
7542 ProcessDeclAttributeList(S, Prev, Attr);
7544 if (TSK == TSK_ExplicitInstantiationDefinition)
7545 InstantiateVariableDefinition(D.getIdentifierLoc(), Prev);
7548 // Check the new variable specialization against the parsed input.
7549 if (PrevTemplate && Prev && !Context.hasSameType(Prev->getType(), R)) {
7550 Diag(T->getTypeLoc().getLocStart(),
7551 diag::err_invalid_var_template_spec_type)
7552 << 0 << PrevTemplate << R << Prev->getType();
7553 Diag(PrevTemplate->getLocation(), diag::note_template_declared_here)
7554 << 2 << PrevTemplate->getDeclName();
7558 // FIXME: Create an ExplicitInstantiation node?
7559 return (Decl*) nullptr;
7562 // If the declarator is a template-id, translate the parser's template
7563 // argument list into our AST format.
7564 bool HasExplicitTemplateArgs = false;
7565 TemplateArgumentListInfo TemplateArgs;
7566 if (D.getName().getKind() == UnqualifiedId::IK_TemplateId) {
7567 TemplateArgs = makeTemplateArgumentListInfo(*this, *D.getName().TemplateId);
7568 HasExplicitTemplateArgs = true;
7571 // C++ [temp.explicit]p1:
7572 // A [...] function [...] can be explicitly instantiated from its template.
7573 // A member function [...] of a class template can be explicitly
7574 // instantiated from the member definition associated with its class
7576 UnresolvedSet<8> Matches;
7577 TemplateSpecCandidateSet FailedCandidates(D.getIdentifierLoc());
7578 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
7580 NamedDecl *Prev = *P;
7581 if (!HasExplicitTemplateArgs) {
7582 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Prev)) {
7583 QualType Adjusted = adjustCCAndNoReturn(R, Method->getType());
7584 if (Context.hasSameUnqualifiedType(Method->getType(), Adjusted)) {
7587 Matches.addDecl(Method, P.getAccess());
7588 if (Method->getTemplateSpecializationKind() == TSK_Undeclared)
7594 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Prev);
7598 TemplateDeductionInfo Info(FailedCandidates.getLocation());
7599 FunctionDecl *Specialization = nullptr;
7600 if (TemplateDeductionResult TDK
7601 = DeduceTemplateArguments(FunTmpl,
7602 (HasExplicitTemplateArgs ? &TemplateArgs
7604 R, Specialization, Info)) {
7605 // Keep track of almost-matches.
7606 FailedCandidates.addCandidate()
7607 .set(FunTmpl->getTemplatedDecl(),
7608 MakeDeductionFailureInfo(Context, TDK, Info));
7613 Matches.addDecl(Specialization, P.getAccess());
7616 // Find the most specialized function template specialization.
7617 UnresolvedSetIterator Result = getMostSpecialized(
7618 Matches.begin(), Matches.end(), FailedCandidates,
7619 D.getIdentifierLoc(),
7620 PDiag(diag::err_explicit_instantiation_not_known) << Name,
7621 PDiag(diag::err_explicit_instantiation_ambiguous) << Name,
7622 PDiag(diag::note_explicit_instantiation_candidate));
7624 if (Result == Matches.end())
7627 // Ignore access control bits, we don't need them for redeclaration checking.
7628 FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
7630 // C++11 [except.spec]p4
7631 // In an explicit instantiation an exception-specification may be specified,
7632 // but is not required.
7633 // If an exception-specification is specified in an explicit instantiation
7634 // directive, it shall be compatible with the exception-specifications of
7635 // other declarations of that function.
7636 if (auto *FPT = R->getAs<FunctionProtoType>())
7637 if (FPT->hasExceptionSpec()) {
7639 diag::err_mismatched_exception_spec_explicit_instantiation;
7640 if (getLangOpts().MicrosoftExt)
7641 DiagID = diag::ext_mismatched_exception_spec_explicit_instantiation;
7642 bool Result = CheckEquivalentExceptionSpec(
7643 PDiag(DiagID) << Specialization->getType(),
7644 PDiag(diag::note_explicit_instantiation_here),
7645 Specialization->getType()->getAs<FunctionProtoType>(),
7646 Specialization->getLocation(), FPT, D.getLocStart());
7647 // In Microsoft mode, mismatching exception specifications just cause a
7649 if (!getLangOpts().MicrosoftExt && Result)
7653 if (Specialization->getTemplateSpecializationKind() == TSK_Undeclared) {
7654 Diag(D.getIdentifierLoc(),
7655 diag::err_explicit_instantiation_member_function_not_instantiated)
7657 << (Specialization->getTemplateSpecializationKind() ==
7658 TSK_ExplicitSpecialization);
7659 Diag(Specialization->getLocation(), diag::note_explicit_instantiation_here);
7663 FunctionDecl *PrevDecl = Specialization->getPreviousDecl();
7664 if (!PrevDecl && Specialization->isThisDeclarationADefinition())
7665 PrevDecl = Specialization;
7668 bool HasNoEffect = false;
7669 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK,
7671 PrevDecl->getTemplateSpecializationKind(),
7672 PrevDecl->getPointOfInstantiation(),
7676 // FIXME: We may still want to build some representation of this
7677 // explicit specialization.
7679 return (Decl*) nullptr;
7682 Specialization->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
7683 AttributeList *Attr = D.getDeclSpec().getAttributes().getList();
7685 ProcessDeclAttributeList(S, Specialization, Attr);
7687 if (Specialization->isDefined()) {
7688 // Let the ASTConsumer know that this function has been explicitly
7689 // instantiated now, and its linkage might have changed.
7690 Consumer.HandleTopLevelDecl(DeclGroupRef(Specialization));
7691 } else if (TSK == TSK_ExplicitInstantiationDefinition)
7692 InstantiateFunctionDefinition(D.getIdentifierLoc(), Specialization);
7694 // C++0x [temp.explicit]p2:
7695 // If the explicit instantiation is for a member function, a member class
7696 // or a static data member of a class template specialization, the name of
7697 // the class template specialization in the qualified-id for the member
7698 // name shall be a simple-template-id.
7700 // C++98 has the same restriction, just worded differently.
7701 FunctionTemplateDecl *FunTmpl = Specialization->getPrimaryTemplate();
7702 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId && !FunTmpl &&
7703 D.getCXXScopeSpec().isSet() &&
7704 !ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()))
7705 Diag(D.getIdentifierLoc(),
7706 diag::ext_explicit_instantiation_without_qualified_id)
7707 << Specialization << D.getCXXScopeSpec().getRange();
7709 CheckExplicitInstantiationScope(*this,
7710 FunTmpl? (NamedDecl *)FunTmpl
7711 : Specialization->getInstantiatedFromMemberFunction(),
7712 D.getIdentifierLoc(),
7713 D.getCXXScopeSpec().isSet());
7715 // FIXME: Create some kind of ExplicitInstantiationDecl here.
7716 return (Decl*) nullptr;
7720 Sema::ActOnDependentTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
7721 const CXXScopeSpec &SS, IdentifierInfo *Name,
7722 SourceLocation TagLoc, SourceLocation NameLoc) {
7723 // This has to hold, because SS is expected to be defined.
7724 assert(Name && "Expected a name in a dependent tag");
7726 NestedNameSpecifier *NNS = SS.getScopeRep();
7730 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
7732 if (TUK == TUK_Declaration || TUK == TUK_Definition) {
7733 Diag(NameLoc, diag::err_dependent_tag_decl)
7734 << (TUK == TUK_Definition) << Kind << SS.getRange();
7738 // Create the resulting type.
7739 ElaboratedTypeKeyword Kwd = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
7740 QualType Result = Context.getDependentNameType(Kwd, NNS, Name);
7742 // Create type-source location information for this type.
7744 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(Result);
7745 TL.setElaboratedKeywordLoc(TagLoc);
7746 TL.setQualifierLoc(SS.getWithLocInContext(Context));
7747 TL.setNameLoc(NameLoc);
7748 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
7752 Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc,
7753 const CXXScopeSpec &SS, const IdentifierInfo &II,
7754 SourceLocation IdLoc) {
7758 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
7760 getLangOpts().CPlusPlus11 ?
7761 diag::warn_cxx98_compat_typename_outside_of_template :
7762 diag::ext_typename_outside_of_template)
7763 << FixItHint::CreateRemoval(TypenameLoc);
7765 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
7766 QualType T = CheckTypenameType(TypenameLoc.isValid()? ETK_Typename : ETK_None,
7767 TypenameLoc, QualifierLoc, II, IdLoc);
7771 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
7772 if (isa<DependentNameType>(T)) {
7773 DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
7774 TL.setElaboratedKeywordLoc(TypenameLoc);
7775 TL.setQualifierLoc(QualifierLoc);
7776 TL.setNameLoc(IdLoc);
7778 ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>();
7779 TL.setElaboratedKeywordLoc(TypenameLoc);
7780 TL.setQualifierLoc(QualifierLoc);
7781 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
7784 return CreateParsedType(T, TSI);
7788 Sema::ActOnTypenameType(Scope *S,
7789 SourceLocation TypenameLoc,
7790 const CXXScopeSpec &SS,
7791 SourceLocation TemplateKWLoc,
7792 TemplateTy TemplateIn,
7793 SourceLocation TemplateNameLoc,
7794 SourceLocation LAngleLoc,
7795 ASTTemplateArgsPtr TemplateArgsIn,
7796 SourceLocation RAngleLoc) {
7797 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
7799 getLangOpts().CPlusPlus11 ?
7800 diag::warn_cxx98_compat_typename_outside_of_template :
7801 diag::ext_typename_outside_of_template)
7802 << FixItHint::CreateRemoval(TypenameLoc);
7804 // Translate the parser's template argument list in our AST format.
7805 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
7806 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
7808 TemplateName Template = TemplateIn.get();
7809 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
7810 // Construct a dependent template specialization type.
7811 assert(DTN && "dependent template has non-dependent name?");
7812 assert(DTN->getQualifier() == SS.getScopeRep());
7813 QualType T = Context.getDependentTemplateSpecializationType(ETK_Typename,
7814 DTN->getQualifier(),
7815 DTN->getIdentifier(),
7818 // Create source-location information for this type.
7819 TypeLocBuilder Builder;
7820 DependentTemplateSpecializationTypeLoc SpecTL
7821 = Builder.push<DependentTemplateSpecializationTypeLoc>(T);
7822 SpecTL.setElaboratedKeywordLoc(TypenameLoc);
7823 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
7824 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
7825 SpecTL.setTemplateNameLoc(TemplateNameLoc);
7826 SpecTL.setLAngleLoc(LAngleLoc);
7827 SpecTL.setRAngleLoc(RAngleLoc);
7828 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
7829 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
7830 return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
7833 QualType T = CheckTemplateIdType(Template, TemplateNameLoc, TemplateArgs);
7837 // Provide source-location information for the template specialization type.
7838 TypeLocBuilder Builder;
7839 TemplateSpecializationTypeLoc SpecTL
7840 = Builder.push<TemplateSpecializationTypeLoc>(T);
7841 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
7842 SpecTL.setTemplateNameLoc(TemplateNameLoc);
7843 SpecTL.setLAngleLoc(LAngleLoc);
7844 SpecTL.setRAngleLoc(RAngleLoc);
7845 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
7846 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
7848 T = Context.getElaboratedType(ETK_Typename, SS.getScopeRep(), T);
7849 ElaboratedTypeLoc TL = Builder.push<ElaboratedTypeLoc>(T);
7850 TL.setElaboratedKeywordLoc(TypenameLoc);
7851 TL.setQualifierLoc(SS.getWithLocInContext(Context));
7853 TypeSourceInfo *TSI = Builder.getTypeSourceInfo(Context, T);
7854 return CreateParsedType(T, TSI);
7858 /// Determine whether this failed name lookup should be treated as being
7859 /// disabled by a usage of std::enable_if.
7860 static bool isEnableIf(NestedNameSpecifierLoc NNS, const IdentifierInfo &II,
7861 SourceRange &CondRange) {
7862 // We must be looking for a ::type...
7863 if (!II.isStr("type"))
7866 // ... within an explicitly-written template specialization...
7867 if (!NNS || !NNS.getNestedNameSpecifier()->getAsType())
7869 TypeLoc EnableIfTy = NNS.getTypeLoc();
7870 TemplateSpecializationTypeLoc EnableIfTSTLoc =
7871 EnableIfTy.getAs<TemplateSpecializationTypeLoc>();
7872 if (!EnableIfTSTLoc || EnableIfTSTLoc.getNumArgs() == 0)
7874 const TemplateSpecializationType *EnableIfTST =
7875 cast<TemplateSpecializationType>(EnableIfTSTLoc.getTypePtr());
7877 // ... which names a complete class template declaration...
7878 const TemplateDecl *EnableIfDecl =
7879 EnableIfTST->getTemplateName().getAsTemplateDecl();
7880 if (!EnableIfDecl || EnableIfTST->isIncompleteType())
7883 // ... called "enable_if".
7884 const IdentifierInfo *EnableIfII =
7885 EnableIfDecl->getDeclName().getAsIdentifierInfo();
7886 if (!EnableIfII || !EnableIfII->isStr("enable_if"))
7889 // Assume the first template argument is the condition.
7890 CondRange = EnableIfTSTLoc.getArgLoc(0).getSourceRange();
7894 /// \brief Build the type that describes a C++ typename specifier,
7895 /// e.g., "typename T::type".
7897 Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword,
7898 SourceLocation KeywordLoc,
7899 NestedNameSpecifierLoc QualifierLoc,
7900 const IdentifierInfo &II,
7901 SourceLocation IILoc) {
7903 SS.Adopt(QualifierLoc);
7905 DeclContext *Ctx = computeDeclContext(SS);
7907 // If the nested-name-specifier is dependent and couldn't be
7908 // resolved to a type, build a typename type.
7909 assert(QualifierLoc.getNestedNameSpecifier()->isDependent());
7910 return Context.getDependentNameType(Keyword,
7911 QualifierLoc.getNestedNameSpecifier(),
7915 // If the nested-name-specifier refers to the current instantiation,
7916 // the "typename" keyword itself is superfluous. In C++03, the
7917 // program is actually ill-formed. However, DR 382 (in C++0x CD1)
7918 // allows such extraneous "typename" keywords, and we retroactively
7919 // apply this DR to C++03 code with only a warning. In any case we continue.
7921 if (RequireCompleteDeclContext(SS, Ctx))
7924 DeclarationName Name(&II);
7925 LookupResult Result(*this, Name, IILoc, LookupOrdinaryName);
7926 NestedNameSpecifier *NNS = SS.getScopeRep();
7927 if (NNS->getKind() == NestedNameSpecifier::Super)
7928 LookupInSuper(Result, NNS->getAsRecordDecl());
7930 LookupQualifiedName(Result, Ctx);
7931 unsigned DiagID = 0;
7932 Decl *Referenced = nullptr;
7933 switch (Result.getResultKind()) {
7934 case LookupResult::NotFound: {
7935 // If we're looking up 'type' within a template named 'enable_if', produce
7936 // a more specific diagnostic.
7937 SourceRange CondRange;
7938 if (isEnableIf(QualifierLoc, II, CondRange)) {
7939 Diag(CondRange.getBegin(), diag::err_typename_nested_not_found_enable_if)
7940 << Ctx << CondRange;
7944 DiagID = diag::err_typename_nested_not_found;
7948 case LookupResult::FoundUnresolvedValue: {
7949 // We found a using declaration that is a value. Most likely, the using
7950 // declaration itself is meant to have the 'typename' keyword.
7951 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
7953 Diag(IILoc, diag::err_typename_refers_to_using_value_decl)
7954 << Name << Ctx << FullRange;
7955 if (UnresolvedUsingValueDecl *Using
7956 = dyn_cast<UnresolvedUsingValueDecl>(Result.getRepresentativeDecl())){
7957 SourceLocation Loc = Using->getQualifierLoc().getBeginLoc();
7958 Diag(Loc, diag::note_using_value_decl_missing_typename)
7959 << FixItHint::CreateInsertion(Loc, "typename ");
7962 // Fall through to create a dependent typename type, from which we can recover
7965 case LookupResult::NotFoundInCurrentInstantiation:
7966 // Okay, it's a member of an unknown instantiation.
7967 return Context.getDependentNameType(Keyword,
7968 QualifierLoc.getNestedNameSpecifier(),
7971 case LookupResult::Found:
7972 if (TypeDecl *Type = dyn_cast<TypeDecl>(Result.getFoundDecl())) {
7973 // We found a type. Build an ElaboratedType, since the
7974 // typename-specifier was just sugar.
7975 MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
7976 return Context.getElaboratedType(ETK_Typename,
7977 QualifierLoc.getNestedNameSpecifier(),
7978 Context.getTypeDeclType(Type));
7981 DiagID = diag::err_typename_nested_not_type;
7982 Referenced = Result.getFoundDecl();
7985 case LookupResult::FoundOverloaded:
7986 DiagID = diag::err_typename_nested_not_type;
7987 Referenced = *Result.begin();
7990 case LookupResult::Ambiguous:
7994 // If we get here, it's because name lookup did not find a
7995 // type. Emit an appropriate diagnostic and return an error.
7996 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
7998 Diag(IILoc, DiagID) << FullRange << Name << Ctx;
8000 Diag(Referenced->getLocation(), diag::note_typename_refers_here)
8006 // See Sema::RebuildTypeInCurrentInstantiation
8007 class CurrentInstantiationRebuilder
8008 : public TreeTransform<CurrentInstantiationRebuilder> {
8010 DeclarationName Entity;
8013 typedef TreeTransform<CurrentInstantiationRebuilder> inherited;
8015 CurrentInstantiationRebuilder(Sema &SemaRef,
8017 DeclarationName Entity)
8018 : TreeTransform<CurrentInstantiationRebuilder>(SemaRef),
8019 Loc(Loc), Entity(Entity) { }
8021 /// \brief Determine whether the given type \p T has already been
8024 /// For the purposes of type reconstruction, a type has already been
8025 /// transformed if it is NULL or if it is not dependent.
8026 bool AlreadyTransformed(QualType T) {
8027 return T.isNull() || !T->isDependentType();
8030 /// \brief Returns the location of the entity whose type is being
8032 SourceLocation getBaseLocation() { return Loc; }
8034 /// \brief Returns the name of the entity whose type is being rebuilt.
8035 DeclarationName getBaseEntity() { return Entity; }
8037 /// \brief Sets the "base" location and entity when that
8038 /// information is known based on another transformation.
8039 void setBase(SourceLocation Loc, DeclarationName Entity) {
8041 this->Entity = Entity;
8044 ExprResult TransformLambdaExpr(LambdaExpr *E) {
8045 // Lambdas never need to be transformed.
8051 /// \brief Rebuilds a type within the context of the current instantiation.
8053 /// The type \p T is part of the type of an out-of-line member definition of
8054 /// a class template (or class template partial specialization) that was parsed
8055 /// and constructed before we entered the scope of the class template (or
8056 /// partial specialization thereof). This routine will rebuild that type now
8057 /// that we have entered the declarator's scope, which may produce different
8058 /// canonical types, e.g.,
8061 /// template<typename T>
8063 /// typedef T* pointer;
8067 /// template<typename T>
8068 /// typename X<T>::pointer X<T>::data() { ... }
8071 /// Here, the type "typename X<T>::pointer" will be created as a DependentNameType,
8072 /// since we do not know that we can look into X<T> when we parsed the type.
8073 /// This function will rebuild the type, performing the lookup of "pointer"
8074 /// in X<T> and returning an ElaboratedType whose canonical type is the same
8075 /// as the canonical type of T*, allowing the return types of the out-of-line
8076 /// definition and the declaration to match.
8077 TypeSourceInfo *Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo *T,
8079 DeclarationName Name) {
8080 if (!T || !T->getType()->isDependentType())
8083 CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name);
8084 return Rebuilder.TransformType(T);
8087 ExprResult Sema::RebuildExprInCurrentInstantiation(Expr *E) {
8088 CurrentInstantiationRebuilder Rebuilder(*this, E->getExprLoc(),
8090 return Rebuilder.TransformExpr(E);
8093 bool Sema::RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS) {
8097 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
8098 CurrentInstantiationRebuilder Rebuilder(*this, SS.getRange().getBegin(),
8100 NestedNameSpecifierLoc Rebuilt
8101 = Rebuilder.TransformNestedNameSpecifierLoc(QualifierLoc);
8109 /// \brief Rebuild the template parameters now that we know we're in a current
8111 bool Sema::RebuildTemplateParamsInCurrentInstantiation(
8112 TemplateParameterList *Params) {
8113 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
8114 Decl *Param = Params->getParam(I);
8116 // There is nothing to rebuild in a type parameter.
8117 if (isa<TemplateTypeParmDecl>(Param))
8120 // Rebuild the template parameter list of a template template parameter.
8121 if (TemplateTemplateParmDecl *TTP
8122 = dyn_cast<TemplateTemplateParmDecl>(Param)) {
8123 if (RebuildTemplateParamsInCurrentInstantiation(
8124 TTP->getTemplateParameters()))
8130 // Rebuild the type of a non-type template parameter.
8131 NonTypeTemplateParmDecl *NTTP = cast<NonTypeTemplateParmDecl>(Param);
8132 TypeSourceInfo *NewTSI
8133 = RebuildTypeInCurrentInstantiation(NTTP->getTypeSourceInfo(),
8134 NTTP->getLocation(),
8135 NTTP->getDeclName());
8139 if (NewTSI != NTTP->getTypeSourceInfo()) {
8140 NTTP->setTypeSourceInfo(NewTSI);
8141 NTTP->setType(NewTSI->getType());
8148 /// \brief Produces a formatted string that describes the binding of
8149 /// template parameters to template arguments.
8151 Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
8152 const TemplateArgumentList &Args) {
8153 return getTemplateArgumentBindingsText(Params, Args.data(), Args.size());
8157 Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
8158 const TemplateArgument *Args,
8160 SmallString<128> Str;
8161 llvm::raw_svector_ostream Out(Str);
8163 if (!Params || Params->size() == 0 || NumArgs == 0)
8164 return std::string();
8166 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
8175 if (const IdentifierInfo *Id = Params->getParam(I)->getIdentifier()) {
8176 Out << Id->getName();
8182 Args[I].print(getPrintingPolicy(), Out);
8189 void Sema::MarkAsLateParsedTemplate(FunctionDecl *FD, Decl *FnD,
8190 CachedTokens &Toks) {
8194 LateParsedTemplate *LPT = new LateParsedTemplate;
8196 // Take tokens to avoid allocations
8197 LPT->Toks.swap(Toks);
8199 LateParsedTemplateMap[FD] = LPT;
8201 FD->setLateTemplateParsed(true);
8204 void Sema::UnmarkAsLateParsedTemplate(FunctionDecl *FD) {
8207 FD->setLateTemplateParsed(false);
8210 bool Sema::IsInsideALocalClassWithinATemplateFunction() {
8211 DeclContext *DC = CurContext;
8214 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(CurContext)) {
8215 const FunctionDecl *FD = RD->isLocalClass();
8216 return (FD && FD->getTemplatedKind() != FunctionDecl::TK_NonTemplate);
8217 } else if (DC->isTranslationUnit() || DC->isNamespace())
8220 DC = DC->getParent();