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/Builtins.h"
22 #include "clang/Basic/LangOptions.h"
23 #include "clang/Basic/PartialDiagnostic.h"
24 #include "clang/Basic/TargetInfo.h"
25 #include "clang/Sema/DeclSpec.h"
26 #include "clang/Sema/Lookup.h"
27 #include "clang/Sema/ParsedTemplate.h"
28 #include "clang/Sema/Scope.h"
29 #include "clang/Sema/SemaInternal.h"
30 #include "clang/Sema/Template.h"
31 #include "clang/Sema/TemplateDeduction.h"
32 #include "llvm/ADT/SmallBitVector.h"
33 #include "llvm/ADT/SmallString.h"
34 #include "llvm/ADT/StringExtras.h"
37 using namespace clang;
40 // Exported for use by Parser.
42 clang::getTemplateParamsRange(TemplateParameterList const * const *Ps,
44 if (!N) return SourceRange();
45 return SourceRange(Ps[0]->getTemplateLoc(), Ps[N-1]->getRAngleLoc());
48 /// \brief Determine whether the declaration found is acceptable as the name
49 /// of a template and, if so, return that template declaration. Otherwise,
51 static NamedDecl *isAcceptableTemplateName(ASTContext &Context,
53 bool AllowFunctionTemplates) {
54 NamedDecl *D = Orig->getUnderlyingDecl();
56 if (isa<TemplateDecl>(D)) {
57 if (!AllowFunctionTemplates && isa<FunctionTemplateDecl>(D))
63 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
64 // C++ [temp.local]p1:
65 // Like normal (non-template) classes, class templates have an
66 // injected-class-name (Clause 9). The injected-class-name
67 // can be used with or without a template-argument-list. When
68 // it is used without a template-argument-list, it is
69 // equivalent to the injected-class-name followed by the
70 // template-parameters of the class template enclosed in
71 // <>. When it is used with a template-argument-list, it
72 // refers to the specified class template specialization,
73 // which could be the current specialization or another
75 if (Record->isInjectedClassName()) {
76 Record = cast<CXXRecordDecl>(Record->getDeclContext());
77 if (Record->getDescribedClassTemplate())
78 return Record->getDescribedClassTemplate();
80 if (ClassTemplateSpecializationDecl *Spec
81 = dyn_cast<ClassTemplateSpecializationDecl>(Record))
82 return Spec->getSpecializedTemplate();
91 void Sema::FilterAcceptableTemplateNames(LookupResult &R,
92 bool AllowFunctionTemplates) {
93 // The set of class templates we've already seen.
94 llvm::SmallPtrSet<ClassTemplateDecl *, 8> ClassTemplates;
95 LookupResult::Filter filter = R.makeFilter();
96 while (filter.hasNext()) {
97 NamedDecl *Orig = filter.next();
98 NamedDecl *Repl = isAcceptableTemplateName(Context, Orig,
99 AllowFunctionTemplates);
102 else if (Repl != Orig) {
104 // C++ [temp.local]p3:
105 // A lookup that finds an injected-class-name (10.2) can result in an
106 // ambiguity in certain cases (for example, if it is found in more than
107 // one base class). If all of the injected-class-names that are found
108 // refer to specializations of the same class template, and if the name
109 // is used as a template-name, the reference refers to the class
110 // template itself and not a specialization thereof, and is not
112 if (ClassTemplateDecl *ClassTmpl = dyn_cast<ClassTemplateDecl>(Repl))
113 if (!ClassTemplates.insert(ClassTmpl).second) {
118 // FIXME: we promote access to public here as a workaround to
119 // the fact that LookupResult doesn't let us remember that we
120 // found this template through a particular injected class name,
121 // which means we end up doing nasty things to the invariants.
122 // Pretending that access is public is *much* safer.
123 filter.replace(Repl, AS_public);
129 bool Sema::hasAnyAcceptableTemplateNames(LookupResult &R,
130 bool AllowFunctionTemplates) {
131 for (LookupResult::iterator I = R.begin(), IEnd = R.end(); I != IEnd; ++I)
132 if (isAcceptableTemplateName(Context, *I, AllowFunctionTemplates))
138 TemplateNameKind Sema::isTemplateName(Scope *S,
140 bool hasTemplateKeyword,
142 ParsedType ObjectTypePtr,
143 bool EnteringContext,
144 TemplateTy &TemplateResult,
145 bool &MemberOfUnknownSpecialization) {
146 assert(getLangOpts().CPlusPlus && "No template names in C!");
148 DeclarationName TName;
149 MemberOfUnknownSpecialization = false;
151 switch (Name.getKind()) {
152 case UnqualifiedId::IK_Identifier:
153 TName = DeclarationName(Name.Identifier);
156 case UnqualifiedId::IK_OperatorFunctionId:
157 TName = Context.DeclarationNames.getCXXOperatorName(
158 Name.OperatorFunctionId.Operator);
161 case UnqualifiedId::IK_LiteralOperatorId:
162 TName = Context.DeclarationNames.getCXXLiteralOperatorName(Name.Identifier);
166 return TNK_Non_template;
169 QualType ObjectType = ObjectTypePtr.get();
171 LookupResult R(*this, TName, Name.getLocStart(), LookupOrdinaryName);
172 LookupTemplateName(R, S, SS, ObjectType, EnteringContext,
173 MemberOfUnknownSpecialization);
174 if (R.empty()) return TNK_Non_template;
175 if (R.isAmbiguous()) {
176 // Suppress diagnostics; we'll redo this lookup later.
177 R.suppressDiagnostics();
179 // FIXME: we might have ambiguous templates, in which case we
180 // should at least parse them properly!
181 return TNK_Non_template;
184 TemplateName Template;
185 TemplateNameKind TemplateKind;
187 unsigned ResultCount = R.end() - R.begin();
188 if (ResultCount > 1) {
189 // We assume that we'll preserve the qualifier from a function
190 // template name in other ways.
191 Template = Context.getOverloadedTemplateName(R.begin(), R.end());
192 TemplateKind = TNK_Function_template;
194 // We'll do this lookup again later.
195 R.suppressDiagnostics();
197 TemplateDecl *TD = cast<TemplateDecl>((*R.begin())->getUnderlyingDecl());
199 if (SS.isSet() && !SS.isInvalid()) {
200 NestedNameSpecifier *Qualifier = SS.getScopeRep();
201 Template = Context.getQualifiedTemplateName(Qualifier,
202 hasTemplateKeyword, TD);
204 Template = TemplateName(TD);
207 if (isa<FunctionTemplateDecl>(TD)) {
208 TemplateKind = TNK_Function_template;
210 // We'll do this lookup again later.
211 R.suppressDiagnostics();
213 assert(isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) ||
214 isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD) ||
215 isa<BuiltinTemplateDecl>(TD));
217 isa<VarTemplateDecl>(TD) ? TNK_Var_template : TNK_Type_template;
221 TemplateResult = TemplateTy::make(Template);
225 bool Sema::DiagnoseUnknownTemplateName(const IdentifierInfo &II,
226 SourceLocation IILoc,
228 const CXXScopeSpec *SS,
229 TemplateTy &SuggestedTemplate,
230 TemplateNameKind &SuggestedKind) {
231 // We can't recover unless there's a dependent scope specifier preceding the
233 // FIXME: Typo correction?
234 if (!SS || !SS->isSet() || !isDependentScopeSpecifier(*SS) ||
235 computeDeclContext(*SS))
238 // The code is missing a 'template' keyword prior to the dependent template
240 NestedNameSpecifier *Qualifier = (NestedNameSpecifier*)SS->getScopeRep();
241 Diag(IILoc, diag::err_template_kw_missing)
242 << Qualifier << II.getName()
243 << FixItHint::CreateInsertion(IILoc, "template ");
245 = TemplateTy::make(Context.getDependentTemplateName(Qualifier, &II));
246 SuggestedKind = TNK_Dependent_template_name;
250 void Sema::LookupTemplateName(LookupResult &Found,
251 Scope *S, CXXScopeSpec &SS,
253 bool EnteringContext,
254 bool &MemberOfUnknownSpecialization) {
255 // Determine where to perform name lookup
256 MemberOfUnknownSpecialization = false;
257 DeclContext *LookupCtx = nullptr;
258 bool isDependent = false;
259 if (!ObjectType.isNull()) {
260 // This nested-name-specifier occurs in a member access expression, e.g.,
261 // x->B::f, and we are looking into the type of the object.
262 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist");
263 LookupCtx = computeDeclContext(ObjectType);
264 isDependent = ObjectType->isDependentType();
265 assert((isDependent || !ObjectType->isIncompleteType() ||
266 ObjectType->castAs<TagType>()->isBeingDefined()) &&
267 "Caller should have completed object type");
269 // Template names cannot appear inside an Objective-C class or object type.
270 if (ObjectType->isObjCObjectOrInterfaceType()) {
274 } else if (SS.isSet()) {
275 // This nested-name-specifier occurs after another nested-name-specifier,
276 // so long into the context associated with the prior nested-name-specifier.
277 LookupCtx = computeDeclContext(SS, EnteringContext);
278 isDependent = isDependentScopeSpecifier(SS);
280 // The declaration context must be complete.
281 if (LookupCtx && RequireCompleteDeclContext(SS, LookupCtx))
285 bool ObjectTypeSearchedInScope = false;
286 bool AllowFunctionTemplatesInLookup = true;
288 // Perform "qualified" name lookup into the declaration context we
289 // computed, which is either the type of the base of a member access
290 // expression or the declaration context associated with a prior
291 // nested-name-specifier.
292 LookupQualifiedName(Found, LookupCtx);
293 if (!ObjectType.isNull() && Found.empty()) {
294 // C++ [basic.lookup.classref]p1:
295 // In a class member access expression (5.2.5), if the . or -> token is
296 // immediately followed by an identifier followed by a <, the
297 // identifier must be looked up to determine whether the < is the
298 // beginning of a template argument list (14.2) or a less-than operator.
299 // The identifier is first looked up in the class of the object
300 // expression. If the identifier is not found, it is then looked up in
301 // the context of the entire postfix-expression and shall name a class
302 // or function template.
303 if (S) LookupName(Found, S);
304 ObjectTypeSearchedInScope = true;
305 AllowFunctionTemplatesInLookup = false;
307 } else if (isDependent && (!S || ObjectType.isNull())) {
308 // We cannot look into a dependent object type or nested nme
310 MemberOfUnknownSpecialization = true;
313 // Perform unqualified name lookup in the current scope.
314 LookupName(Found, S);
316 if (!ObjectType.isNull())
317 AllowFunctionTemplatesInLookup = false;
320 if (Found.empty() && !isDependent) {
321 // If we did not find any names, attempt to correct any typos.
322 DeclarationName Name = Found.getLookupName();
324 // Simple filter callback that, for keywords, only accepts the C++ *_cast
325 auto FilterCCC = llvm::make_unique<CorrectionCandidateCallback>();
326 FilterCCC->WantTypeSpecifiers = false;
327 FilterCCC->WantExpressionKeywords = false;
328 FilterCCC->WantRemainingKeywords = false;
329 FilterCCC->WantCXXNamedCasts = true;
330 if (TypoCorrection Corrected = CorrectTypo(
331 Found.getLookupNameInfo(), Found.getLookupKind(), S, &SS,
332 std::move(FilterCCC), CTK_ErrorRecovery, LookupCtx)) {
333 Found.setLookupName(Corrected.getCorrection());
334 if (auto *ND = Corrected.getFoundDecl())
336 FilterAcceptableTemplateNames(Found);
337 if (!Found.empty()) {
339 std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
340 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
341 Name.getAsString() == CorrectedStr;
342 diagnoseTypo(Corrected, PDiag(diag::err_no_member_template_suggest)
343 << Name << LookupCtx << DroppedSpecifier
346 diagnoseTypo(Corrected, PDiag(diag::err_no_template_suggest) << Name);
350 Found.setLookupName(Name);
354 FilterAcceptableTemplateNames(Found, AllowFunctionTemplatesInLookup);
357 MemberOfUnknownSpecialization = true;
361 if (S && !ObjectType.isNull() && !ObjectTypeSearchedInScope &&
362 !getLangOpts().CPlusPlus11) {
363 // C++03 [basic.lookup.classref]p1:
364 // [...] If the lookup in the class of the object expression finds a
365 // template, the name is also looked up in the context of the entire
366 // postfix-expression and [...]
368 // Note: C++11 does not perform this second lookup.
369 LookupResult FoundOuter(*this, Found.getLookupName(), Found.getNameLoc(),
371 LookupName(FoundOuter, S);
372 FilterAcceptableTemplateNames(FoundOuter, /*AllowFunctionTemplates=*/false);
374 if (FoundOuter.empty()) {
375 // - if the name is not found, the name found in the class of the
376 // object expression is used, otherwise
377 } else if (!FoundOuter.getAsSingle<ClassTemplateDecl>() ||
378 FoundOuter.isAmbiguous()) {
379 // - if the name is found in the context of the entire
380 // postfix-expression and does not name a class template, the name
381 // found in the class of the object expression is used, otherwise
383 } else if (!Found.isSuppressingDiagnostics()) {
384 // - if the name found is a class template, it must refer to the same
385 // entity as the one found in the class of the object expression,
386 // otherwise the program is ill-formed.
387 if (!Found.isSingleResult() ||
388 Found.getFoundDecl()->getCanonicalDecl()
389 != FoundOuter.getFoundDecl()->getCanonicalDecl()) {
390 Diag(Found.getNameLoc(),
391 diag::ext_nested_name_member_ref_lookup_ambiguous)
392 << Found.getLookupName()
394 Diag(Found.getRepresentativeDecl()->getLocation(),
395 diag::note_ambig_member_ref_object_type)
397 Diag(FoundOuter.getFoundDecl()->getLocation(),
398 diag::note_ambig_member_ref_scope);
400 // Recover by taking the template that we found in the object
401 // expression's type.
407 /// ActOnDependentIdExpression - Handle a dependent id-expression that
408 /// was just parsed. This is only possible with an explicit scope
409 /// specifier naming a dependent type.
411 Sema::ActOnDependentIdExpression(const CXXScopeSpec &SS,
412 SourceLocation TemplateKWLoc,
413 const DeclarationNameInfo &NameInfo,
414 bool isAddressOfOperand,
415 const TemplateArgumentListInfo *TemplateArgs) {
416 DeclContext *DC = getFunctionLevelDeclContext();
418 // C++11 [expr.prim.general]p12:
419 // An id-expression that denotes a non-static data member or non-static
420 // member function of a class can only be used:
422 // - if that id-expression denotes a non-static data member and it
423 // appears in an unevaluated operand.
425 // If this might be the case, form a DependentScopeDeclRefExpr instead of a
426 // CXXDependentScopeMemberExpr. The former can instantiate to either
427 // DeclRefExpr or MemberExpr depending on lookup results, while the latter is
428 // always a MemberExpr.
429 bool MightBeCxx11UnevalField =
430 getLangOpts().CPlusPlus11 && isUnevaluatedContext();
432 // Check if the nested name specifier is an enum type.
434 if (NestedNameSpecifier *NNS = SS.getScopeRep())
435 IsEnum = dyn_cast_or_null<EnumType>(NNS->getAsType());
437 if (!MightBeCxx11UnevalField && !isAddressOfOperand && !IsEnum &&
438 isa<CXXMethodDecl>(DC) && cast<CXXMethodDecl>(DC)->isInstance()) {
439 QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType(Context);
441 // Since the 'this' expression is synthesized, we don't need to
442 // perform the double-lookup check.
443 NamedDecl *FirstQualifierInScope = nullptr;
445 return CXXDependentScopeMemberExpr::Create(
446 Context, /*This*/ nullptr, ThisType, /*IsArrow*/ true,
447 /*Op*/ SourceLocation(), SS.getWithLocInContext(Context), TemplateKWLoc,
448 FirstQualifierInScope, NameInfo, TemplateArgs);
451 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
455 Sema::BuildDependentDeclRefExpr(const CXXScopeSpec &SS,
456 SourceLocation TemplateKWLoc,
457 const DeclarationNameInfo &NameInfo,
458 const TemplateArgumentListInfo *TemplateArgs) {
459 return DependentScopeDeclRefExpr::Create(
460 Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo,
465 /// Determine whether we would be unable to instantiate this template (because
466 /// it either has no definition, or is in the process of being instantiated).
467 bool Sema::DiagnoseUninstantiableTemplate(SourceLocation PointOfInstantiation,
468 NamedDecl *Instantiation,
469 bool InstantiatedFromMember,
470 const NamedDecl *Pattern,
471 const NamedDecl *PatternDef,
472 TemplateSpecializationKind TSK,
473 bool Complain /*= true*/) {
474 assert(isa<TagDecl>(Instantiation) || isa<FunctionDecl>(Instantiation) ||
475 isa<VarDecl>(Instantiation));
477 bool IsEntityBeingDefined = false;
478 if (const TagDecl *TD = dyn_cast_or_null<TagDecl>(PatternDef))
479 IsEntityBeingDefined = TD->isBeingDefined();
481 if (PatternDef && !IsEntityBeingDefined) {
482 NamedDecl *SuggestedDef = nullptr;
483 if (!hasVisibleDefinition(const_cast<NamedDecl*>(PatternDef), &SuggestedDef,
484 /*OnlyNeedComplete*/false)) {
485 // If we're allowed to diagnose this and recover, do so.
486 bool Recover = Complain && !isSFINAEContext();
488 diagnoseMissingImport(PointOfInstantiation, SuggestedDef,
489 Sema::MissingImportKind::Definition, Recover);
495 if (!Complain || (PatternDef && PatternDef->isInvalidDecl()))
498 llvm::Optional<unsigned> Note;
499 QualType InstantiationTy;
500 if (TagDecl *TD = dyn_cast<TagDecl>(Instantiation))
501 InstantiationTy = Context.getTypeDeclType(TD);
503 Diag(PointOfInstantiation,
504 diag::err_template_instantiate_within_definition)
505 << /*implicit|explicit*/(TSK != TSK_ImplicitInstantiation)
507 // Not much point in noting the template declaration here, since
508 // we're lexically inside it.
509 Instantiation->setInvalidDecl();
510 } else if (InstantiatedFromMember) {
511 if (isa<FunctionDecl>(Instantiation)) {
512 Diag(PointOfInstantiation,
513 diag::err_explicit_instantiation_undefined_member)
514 << /*member function*/ 1 << Instantiation->getDeclName()
515 << Instantiation->getDeclContext();
516 Note = diag::note_explicit_instantiation_here;
518 assert(isa<TagDecl>(Instantiation) && "Must be a TagDecl!");
519 Diag(PointOfInstantiation,
520 diag::err_implicit_instantiate_member_undefined)
522 Note = diag::note_member_declared_at;
525 if (isa<FunctionDecl>(Instantiation)) {
526 Diag(PointOfInstantiation,
527 diag::err_explicit_instantiation_undefined_func_template)
529 Note = diag::note_explicit_instantiation_here;
530 } else if (isa<TagDecl>(Instantiation)) {
531 Diag(PointOfInstantiation, diag::err_template_instantiate_undefined)
532 << (TSK != TSK_ImplicitInstantiation)
534 Note = diag::note_template_decl_here;
536 assert(isa<VarDecl>(Instantiation) && "Must be a VarDecl!");
537 if (isa<VarTemplateSpecializationDecl>(Instantiation)) {
538 Diag(PointOfInstantiation,
539 diag::err_explicit_instantiation_undefined_var_template)
541 Instantiation->setInvalidDecl();
543 Diag(PointOfInstantiation,
544 diag::err_explicit_instantiation_undefined_member)
545 << /*static data member*/ 2 << Instantiation->getDeclName()
546 << Instantiation->getDeclContext();
547 Note = diag::note_explicit_instantiation_here;
550 if (Note) // Diagnostics were emitted.
551 Diag(Pattern->getLocation(), Note.getValue());
553 // In general, Instantiation isn't marked invalid to get more than one
554 // error for multiple undefined instantiations. But the code that does
555 // explicit declaration -> explicit definition conversion can't handle
556 // invalid declarations, so mark as invalid in that case.
557 if (TSK == TSK_ExplicitInstantiationDeclaration)
558 Instantiation->setInvalidDecl();
562 /// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining
563 /// that the template parameter 'PrevDecl' is being shadowed by a new
564 /// declaration at location Loc. Returns true to indicate that this is
565 /// an error, and false otherwise.
566 void Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl) {
567 assert(PrevDecl->isTemplateParameter() && "Not a template parameter");
569 // Microsoft Visual C++ permits template parameters to be shadowed.
570 if (getLangOpts().MicrosoftExt)
573 // C++ [temp.local]p4:
574 // A template-parameter shall not be redeclared within its
575 // scope (including nested scopes).
576 Diag(Loc, diag::err_template_param_shadow)
577 << cast<NamedDecl>(PrevDecl)->getDeclName();
578 Diag(PrevDecl->getLocation(), diag::note_template_param_here);
581 /// AdjustDeclIfTemplate - If the given decl happens to be a template, reset
582 /// the parameter D to reference the templated declaration and return a pointer
583 /// to the template declaration. Otherwise, do nothing to D and return null.
584 TemplateDecl *Sema::AdjustDeclIfTemplate(Decl *&D) {
585 if (TemplateDecl *Temp = dyn_cast_or_null<TemplateDecl>(D)) {
586 D = Temp->getTemplatedDecl();
592 ParsedTemplateArgument ParsedTemplateArgument::getTemplatePackExpansion(
593 SourceLocation EllipsisLoc) const {
594 assert(Kind == Template &&
595 "Only template template arguments can be pack expansions here");
596 assert(getAsTemplate().get().containsUnexpandedParameterPack() &&
597 "Template template argument pack expansion without packs");
598 ParsedTemplateArgument Result(*this);
599 Result.EllipsisLoc = EllipsisLoc;
603 static TemplateArgumentLoc translateTemplateArgument(Sema &SemaRef,
604 const ParsedTemplateArgument &Arg) {
606 switch (Arg.getKind()) {
607 case ParsedTemplateArgument::Type: {
609 QualType T = SemaRef.GetTypeFromParser(Arg.getAsType(), &DI);
611 DI = SemaRef.Context.getTrivialTypeSourceInfo(T, Arg.getLocation());
612 return TemplateArgumentLoc(TemplateArgument(T), DI);
615 case ParsedTemplateArgument::NonType: {
616 Expr *E = static_cast<Expr *>(Arg.getAsExpr());
617 return TemplateArgumentLoc(TemplateArgument(E), E);
620 case ParsedTemplateArgument::Template: {
621 TemplateName Template = Arg.getAsTemplate().get();
622 TemplateArgument TArg;
623 if (Arg.getEllipsisLoc().isValid())
624 TArg = TemplateArgument(Template, Optional<unsigned int>());
627 return TemplateArgumentLoc(TArg,
628 Arg.getScopeSpec().getWithLocInContext(
631 Arg.getEllipsisLoc());
635 llvm_unreachable("Unhandled parsed template argument");
638 /// \brief Translates template arguments as provided by the parser
639 /// into template arguments used by semantic analysis.
640 void Sema::translateTemplateArguments(const ASTTemplateArgsPtr &TemplateArgsIn,
641 TemplateArgumentListInfo &TemplateArgs) {
642 for (unsigned I = 0, Last = TemplateArgsIn.size(); I != Last; ++I)
643 TemplateArgs.addArgument(translateTemplateArgument(*this,
647 static void maybeDiagnoseTemplateParameterShadow(Sema &SemaRef, Scope *S,
649 IdentifierInfo *Name) {
650 NamedDecl *PrevDecl = SemaRef.LookupSingleName(
651 S, Name, Loc, Sema::LookupOrdinaryName, Sema::ForRedeclaration);
652 if (PrevDecl && PrevDecl->isTemplateParameter())
653 SemaRef.DiagnoseTemplateParameterShadow(Loc, PrevDecl);
656 /// ActOnTypeParameter - Called when a C++ template type parameter
657 /// (e.g., "typename T") has been parsed. Typename specifies whether
658 /// the keyword "typename" was used to declare the type parameter
659 /// (otherwise, "class" was used), and KeyLoc is the location of the
660 /// "class" or "typename" keyword. ParamName is the name of the
661 /// parameter (NULL indicates an unnamed template parameter) and
662 /// ParamNameLoc is the location of the parameter name (if any).
663 /// If the type parameter has a default argument, it will be added
664 /// later via ActOnTypeParameterDefault.
665 Decl *Sema::ActOnTypeParameter(Scope *S, bool Typename,
666 SourceLocation EllipsisLoc,
667 SourceLocation KeyLoc,
668 IdentifierInfo *ParamName,
669 SourceLocation ParamNameLoc,
670 unsigned Depth, unsigned Position,
671 SourceLocation EqualLoc,
672 ParsedType DefaultArg) {
673 assert(S->isTemplateParamScope() &&
674 "Template type parameter not in template parameter scope!");
676 SourceLocation Loc = ParamNameLoc;
680 bool IsParameterPack = EllipsisLoc.isValid();
681 TemplateTypeParmDecl *Param
682 = TemplateTypeParmDecl::Create(Context, Context.getTranslationUnitDecl(),
683 KeyLoc, Loc, Depth, Position, ParamName,
684 Typename, IsParameterPack);
685 Param->setAccess(AS_public);
688 maybeDiagnoseTemplateParameterShadow(*this, S, ParamNameLoc, ParamName);
690 // Add the template parameter into the current scope.
692 IdResolver.AddDecl(Param);
695 // C++0x [temp.param]p9:
696 // A default template-argument may be specified for any kind of
697 // template-parameter that is not a template parameter pack.
698 if (DefaultArg && IsParameterPack) {
699 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
700 DefaultArg = nullptr;
703 // Handle the default argument, if provided.
705 TypeSourceInfo *DefaultTInfo;
706 GetTypeFromParser(DefaultArg, &DefaultTInfo);
708 assert(DefaultTInfo && "expected source information for type");
710 // Check for unexpanded parameter packs.
711 if (DiagnoseUnexpandedParameterPack(Loc, DefaultTInfo,
712 UPPC_DefaultArgument))
715 // Check the template argument itself.
716 if (CheckTemplateArgument(Param, DefaultTInfo)) {
717 Param->setInvalidDecl();
721 Param->setDefaultArgument(DefaultTInfo);
727 /// \brief Check that the type of a non-type template parameter is
730 /// \returns the (possibly-promoted) parameter type if valid;
731 /// otherwise, produces a diagnostic and returns a NULL type.
732 QualType Sema::CheckNonTypeTemplateParameterType(TypeSourceInfo *&TSI,
733 SourceLocation Loc) {
734 if (TSI->getType()->isUndeducedType()) {
735 // C++1z [temp.dep.expr]p3:
736 // An id-expression is type-dependent if it contains
737 // - an identifier associated by name lookup with a non-type
738 // template-parameter declared with a type that contains a
739 // placeholder type (7.1.7.4),
740 TSI = SubstAutoTypeSourceInfo(TSI, Context.DependentTy);
743 return CheckNonTypeTemplateParameterType(TSI->getType(), Loc);
746 QualType Sema::CheckNonTypeTemplateParameterType(QualType T,
747 SourceLocation Loc) {
748 // We don't allow variably-modified types as the type of non-type template
750 if (T->isVariablyModifiedType()) {
751 Diag(Loc, diag::err_variably_modified_nontype_template_param)
756 // C++ [temp.param]p4:
758 // A non-type template-parameter shall have one of the following
759 // (optionally cv-qualified) types:
761 // -- integral or enumeration type,
762 if (T->isIntegralOrEnumerationType() ||
763 // -- pointer to object or pointer to function,
764 T->isPointerType() ||
765 // -- reference to object or reference to function,
766 T->isReferenceType() ||
767 // -- pointer to member,
768 T->isMemberPointerType() ||
769 // -- std::nullptr_t.
770 T->isNullPtrType() ||
771 // If T is a dependent type, we can't do the check now, so we
772 // assume that it is well-formed.
773 T->isDependentType() ||
774 // Allow use of auto in template parameter declarations.
775 T->isUndeducedType()) {
776 // C++ [temp.param]p5: The top-level cv-qualifiers on the template-parameter
777 // are ignored when determining its type.
778 return T.getUnqualifiedType();
781 // C++ [temp.param]p8:
783 // A non-type template-parameter of type "array of T" or
784 // "function returning T" is adjusted to be of type "pointer to
785 // T" or "pointer to function returning T", respectively.
786 else if (T->isArrayType() || T->isFunctionType())
787 return Context.getDecayedType(T);
789 Diag(Loc, diag::err_template_nontype_parm_bad_type)
795 Decl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
798 SourceLocation EqualLoc,
800 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
802 if (TInfo->getType()->isUndeducedType()) {
803 Diag(D.getIdentifierLoc(),
804 diag::warn_cxx14_compat_template_nontype_parm_auto_type)
805 << QualType(TInfo->getType()->getContainedAutoType(), 0);
808 assert(S->isTemplateParamScope() &&
809 "Non-type template parameter not in template parameter scope!");
810 bool Invalid = false;
812 QualType T = CheckNonTypeTemplateParameterType(TInfo, D.getIdentifierLoc());
814 T = Context.IntTy; // Recover with an 'int' type.
818 IdentifierInfo *ParamName = D.getIdentifier();
819 bool IsParameterPack = D.hasEllipsis();
820 NonTypeTemplateParmDecl *Param
821 = NonTypeTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
823 D.getIdentifierLoc(),
824 Depth, Position, ParamName, T,
825 IsParameterPack, TInfo);
826 Param->setAccess(AS_public);
829 Param->setInvalidDecl();
832 maybeDiagnoseTemplateParameterShadow(*this, S, D.getIdentifierLoc(),
835 // Add the template parameter into the current scope.
837 IdResolver.AddDecl(Param);
840 // C++0x [temp.param]p9:
841 // A default template-argument may be specified for any kind of
842 // template-parameter that is not a template parameter pack.
843 if (Default && IsParameterPack) {
844 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
848 // Check the well-formedness of the default template argument, if provided.
850 // Check for unexpanded parameter packs.
851 if (DiagnoseUnexpandedParameterPack(Default, UPPC_DefaultArgument))
854 TemplateArgument Converted;
855 ExprResult DefaultRes =
856 CheckTemplateArgument(Param, Param->getType(), Default, Converted);
857 if (DefaultRes.isInvalid()) {
858 Param->setInvalidDecl();
861 Default = DefaultRes.get();
863 Param->setDefaultArgument(Default);
869 /// ActOnTemplateTemplateParameter - Called when a C++ template template
870 /// parameter (e.g. T in template <template \<typename> class T> class array)
871 /// has been parsed. S is the current scope.
872 Decl *Sema::ActOnTemplateTemplateParameter(Scope* S,
873 SourceLocation TmpLoc,
874 TemplateParameterList *Params,
875 SourceLocation EllipsisLoc,
876 IdentifierInfo *Name,
877 SourceLocation NameLoc,
880 SourceLocation EqualLoc,
881 ParsedTemplateArgument Default) {
882 assert(S->isTemplateParamScope() &&
883 "Template template parameter not in template parameter scope!");
885 // Construct the parameter object.
886 bool IsParameterPack = EllipsisLoc.isValid();
887 TemplateTemplateParmDecl *Param =
888 TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
889 NameLoc.isInvalid()? TmpLoc : NameLoc,
890 Depth, Position, IsParameterPack,
892 Param->setAccess(AS_public);
894 // If the template template parameter has a name, then link the identifier
895 // into the scope and lookup mechanisms.
897 maybeDiagnoseTemplateParameterShadow(*this, S, NameLoc, Name);
900 IdResolver.AddDecl(Param);
903 if (Params->size() == 0) {
904 Diag(Param->getLocation(), diag::err_template_template_parm_no_parms)
905 << SourceRange(Params->getLAngleLoc(), Params->getRAngleLoc());
906 Param->setInvalidDecl();
909 // C++0x [temp.param]p9:
910 // A default template-argument may be specified for any kind of
911 // template-parameter that is not a template parameter pack.
912 if (IsParameterPack && !Default.isInvalid()) {
913 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
914 Default = ParsedTemplateArgument();
917 if (!Default.isInvalid()) {
918 // Check only that we have a template template argument. We don't want to
919 // try to check well-formedness now, because our template template parameter
920 // might have dependent types in its template parameters, which we wouldn't
921 // be able to match now.
923 // If none of the template template parameter's template arguments mention
924 // other template parameters, we could actually perform more checking here.
925 // However, it isn't worth doing.
926 TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default);
927 if (DefaultArg.getArgument().getAsTemplate().isNull()) {
928 Diag(DefaultArg.getLocation(), diag::err_template_arg_not_valid_template)
929 << DefaultArg.getSourceRange();
933 // Check for unexpanded parameter packs.
934 if (DiagnoseUnexpandedParameterPack(DefaultArg.getLocation(),
935 DefaultArg.getArgument().getAsTemplate(),
936 UPPC_DefaultArgument))
939 Param->setDefaultArgument(Context, DefaultArg);
945 /// ActOnTemplateParameterList - Builds a TemplateParameterList, optionally
946 /// constrained by RequiresClause, that contains the template parameters in
948 TemplateParameterList *
949 Sema::ActOnTemplateParameterList(unsigned Depth,
950 SourceLocation ExportLoc,
951 SourceLocation TemplateLoc,
952 SourceLocation LAngleLoc,
953 ArrayRef<Decl *> Params,
954 SourceLocation RAngleLoc,
955 Expr *RequiresClause) {
956 if (ExportLoc.isValid())
957 Diag(ExportLoc, diag::warn_template_export_unsupported);
959 return TemplateParameterList::Create(
960 Context, TemplateLoc, LAngleLoc,
961 llvm::makeArrayRef((NamedDecl *const *)Params.data(), Params.size()),
962 RAngleLoc, RequiresClause);
965 static void SetNestedNameSpecifier(TagDecl *T, const CXXScopeSpec &SS) {
967 T->setQualifierInfo(SS.getWithLocInContext(T->getASTContext()));
971 Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
972 SourceLocation KWLoc, CXXScopeSpec &SS,
973 IdentifierInfo *Name, SourceLocation NameLoc,
975 TemplateParameterList *TemplateParams,
976 AccessSpecifier AS, SourceLocation ModulePrivateLoc,
977 SourceLocation FriendLoc,
978 unsigned NumOuterTemplateParamLists,
979 TemplateParameterList** OuterTemplateParamLists,
980 SkipBodyInfo *SkipBody) {
981 assert(TemplateParams && TemplateParams->size() > 0 &&
982 "No template parameters");
983 assert(TUK != TUK_Reference && "Can only declare or define class templates");
984 bool Invalid = false;
986 // Check that we can declare a template here.
987 if (CheckTemplateDeclScope(S, TemplateParams))
990 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
991 assert(Kind != TTK_Enum && "can't build template of enumerated type");
993 // There is no such thing as an unnamed class template.
995 Diag(KWLoc, diag::err_template_unnamed_class);
999 // Find any previous declaration with this name. For a friend with no
1000 // scope explicitly specified, we only look for tag declarations (per
1001 // C++11 [basic.lookup.elab]p2).
1002 DeclContext *SemanticContext;
1003 LookupResult Previous(*this, Name, NameLoc,
1004 (SS.isEmpty() && TUK == TUK_Friend)
1005 ? LookupTagName : LookupOrdinaryName,
1007 if (SS.isNotEmpty() && !SS.isInvalid()) {
1008 SemanticContext = computeDeclContext(SS, true);
1009 if (!SemanticContext) {
1010 // FIXME: Horrible, horrible hack! We can't currently represent this
1011 // in the AST, and historically we have just ignored such friend
1012 // class templates, so don't complain here.
1013 Diag(NameLoc, TUK == TUK_Friend
1014 ? diag::warn_template_qualified_friend_ignored
1015 : diag::err_template_qualified_declarator_no_match)
1016 << SS.getScopeRep() << SS.getRange();
1017 return TUK != TUK_Friend;
1020 if (RequireCompleteDeclContext(SS, SemanticContext))
1023 // If we're adding a template to a dependent context, we may need to
1024 // rebuilding some of the types used within the template parameter list,
1025 // now that we know what the current instantiation is.
1026 if (SemanticContext->isDependentContext()) {
1027 ContextRAII SavedContext(*this, SemanticContext);
1028 if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
1030 } else if (TUK != TUK_Friend && TUK != TUK_Reference)
1031 diagnoseQualifiedDeclaration(SS, SemanticContext, Name, NameLoc);
1033 LookupQualifiedName(Previous, SemanticContext);
1035 SemanticContext = CurContext;
1037 // C++14 [class.mem]p14:
1038 // If T is the name of a class, then each of the following shall have a
1039 // name different from T:
1040 // -- every member template of class T
1041 if (TUK != TUK_Friend &&
1042 DiagnoseClassNameShadow(SemanticContext,
1043 DeclarationNameInfo(Name, NameLoc)))
1046 LookupName(Previous, S);
1049 if (Previous.isAmbiguous())
1052 NamedDecl *PrevDecl = nullptr;
1053 if (Previous.begin() != Previous.end())
1054 PrevDecl = (*Previous.begin())->getUnderlyingDecl();
1056 if (PrevDecl && PrevDecl->isTemplateParameter()) {
1057 // Maybe we will complain about the shadowed template parameter.
1058 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl);
1059 // Just pretend that we didn't see the previous declaration.
1063 // If there is a previous declaration with the same name, check
1064 // whether this is a valid redeclaration.
1065 ClassTemplateDecl *PrevClassTemplate
1066 = dyn_cast_or_null<ClassTemplateDecl>(PrevDecl);
1068 // We may have found the injected-class-name of a class template,
1069 // class template partial specialization, or class template specialization.
1070 // In these cases, grab the template that is being defined or specialized.
1071 if (!PrevClassTemplate && PrevDecl && isa<CXXRecordDecl>(PrevDecl) &&
1072 cast<CXXRecordDecl>(PrevDecl)->isInjectedClassName()) {
1073 PrevDecl = cast<CXXRecordDecl>(PrevDecl->getDeclContext());
1075 = cast<CXXRecordDecl>(PrevDecl)->getDescribedClassTemplate();
1076 if (!PrevClassTemplate && isa<ClassTemplateSpecializationDecl>(PrevDecl)) {
1078 = cast<ClassTemplateSpecializationDecl>(PrevDecl)
1079 ->getSpecializedTemplate();
1083 if (TUK == TUK_Friend) {
1084 // C++ [namespace.memdef]p3:
1085 // [...] When looking for a prior declaration of a class or a function
1086 // declared as a friend, and when the name of the friend class or
1087 // function is neither a qualified name nor a template-id, scopes outside
1088 // the innermost enclosing namespace scope are not considered.
1090 DeclContext *OutermostContext = CurContext;
1091 while (!OutermostContext->isFileContext())
1092 OutermostContext = OutermostContext->getLookupParent();
1095 (OutermostContext->Equals(PrevDecl->getDeclContext()) ||
1096 OutermostContext->Encloses(PrevDecl->getDeclContext()))) {
1097 SemanticContext = PrevDecl->getDeclContext();
1099 // Declarations in outer scopes don't matter. However, the outermost
1100 // context we computed is the semantic context for our new
1102 PrevDecl = PrevClassTemplate = nullptr;
1103 SemanticContext = OutermostContext;
1105 // Check that the chosen semantic context doesn't already contain a
1106 // declaration of this name as a non-tag type.
1107 Previous.clear(LookupOrdinaryName);
1108 DeclContext *LookupContext = SemanticContext;
1109 while (LookupContext->isTransparentContext())
1110 LookupContext = LookupContext->getLookupParent();
1111 LookupQualifiedName(Previous, LookupContext);
1113 if (Previous.isAmbiguous())
1116 if (Previous.begin() != Previous.end())
1117 PrevDecl = (*Previous.begin())->getUnderlyingDecl();
1120 } else if (PrevDecl &&
1121 !isDeclInScope(Previous.getRepresentativeDecl(), SemanticContext,
1123 PrevDecl = PrevClassTemplate = nullptr;
1125 if (auto *Shadow = dyn_cast_or_null<UsingShadowDecl>(
1126 PrevDecl ? Previous.getRepresentativeDecl() : nullptr)) {
1128 !(PrevClassTemplate &&
1129 PrevClassTemplate->getDeclContext()->getRedeclContext()->Equals(
1130 SemanticContext->getRedeclContext()))) {
1131 Diag(KWLoc, diag::err_using_decl_conflict_reverse);
1132 Diag(Shadow->getTargetDecl()->getLocation(),
1133 diag::note_using_decl_target);
1134 Diag(Shadow->getUsingDecl()->getLocation(), diag::note_using_decl) << 0;
1135 // Recover by ignoring the old declaration.
1136 PrevDecl = PrevClassTemplate = nullptr;
1140 if (PrevClassTemplate) {
1141 // Ensure that the template parameter lists are compatible. Skip this check
1142 // for a friend in a dependent context: the template parameter list itself
1143 // could be dependent.
1144 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
1145 !TemplateParameterListsAreEqual(TemplateParams,
1146 PrevClassTemplate->getTemplateParameters(),
1151 // C++ [temp.class]p4:
1152 // In a redeclaration, partial specialization, explicit
1153 // specialization or explicit instantiation of a class template,
1154 // the class-key shall agree in kind with the original class
1155 // template declaration (7.1.5.3).
1156 RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl();
1157 if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind,
1158 TUK == TUK_Definition, KWLoc, Name)) {
1159 Diag(KWLoc, diag::err_use_with_wrong_tag)
1161 << FixItHint::CreateReplacement(KWLoc, PrevRecordDecl->getKindName());
1162 Diag(PrevRecordDecl->getLocation(), diag::note_previous_use);
1163 Kind = PrevRecordDecl->getTagKind();
1166 // Check for redefinition of this class template.
1167 if (TUK == TUK_Definition) {
1168 if (TagDecl *Def = PrevRecordDecl->getDefinition()) {
1169 // If we have a prior definition that is not visible, treat this as
1170 // simply making that previous definition visible.
1171 NamedDecl *Hidden = nullptr;
1172 if (SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
1173 SkipBody->ShouldSkip = true;
1174 auto *Tmpl = cast<CXXRecordDecl>(Hidden)->getDescribedClassTemplate();
1175 assert(Tmpl && "original definition of a class template is not a "
1177 makeMergedDefinitionVisible(Hidden, KWLoc);
1178 makeMergedDefinitionVisible(Tmpl, KWLoc);
1182 Diag(NameLoc, diag::err_redefinition) << Name;
1183 Diag(Def->getLocation(), diag::note_previous_definition);
1184 // FIXME: Would it make sense to try to "forget" the previous
1185 // definition, as part of error recovery?
1189 } else if (PrevDecl) {
1191 // A class template shall not have the same name as any other
1192 // template, class, function, object, enumeration, enumerator,
1193 // namespace, or type in the same scope (3.3), except as specified
1195 Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
1196 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1200 // Check the template parameter list of this declaration, possibly
1201 // merging in the template parameter list from the previous class
1202 // template declaration. Skip this check for a friend in a dependent
1203 // context, because the template parameter list might be dependent.
1204 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
1205 CheckTemplateParameterList(
1207 PrevClassTemplate ? PrevClassTemplate->getTemplateParameters()
1209 (SS.isSet() && SemanticContext && SemanticContext->isRecord() &&
1210 SemanticContext->isDependentContext())
1211 ? TPC_ClassTemplateMember
1212 : TUK == TUK_Friend ? TPC_FriendClassTemplate
1213 : TPC_ClassTemplate))
1217 // If the name of the template was qualified, we must be defining the
1218 // template out-of-line.
1219 if (!SS.isInvalid() && !Invalid && !PrevClassTemplate) {
1220 Diag(NameLoc, TUK == TUK_Friend ? diag::err_friend_decl_does_not_match
1221 : diag::err_member_decl_does_not_match)
1222 << Name << SemanticContext << /*IsDefinition*/true << SS.getRange();
1227 CXXRecordDecl *NewClass =
1228 CXXRecordDecl::Create(Context, Kind, SemanticContext, KWLoc, NameLoc, Name,
1230 PrevClassTemplate->getTemplatedDecl() : nullptr,
1231 /*DelayTypeCreation=*/true);
1232 SetNestedNameSpecifier(NewClass, SS);
1233 if (NumOuterTemplateParamLists > 0)
1234 NewClass->setTemplateParameterListsInfo(
1235 Context, llvm::makeArrayRef(OuterTemplateParamLists,
1236 NumOuterTemplateParamLists));
1238 // Add alignment attributes if necessary; these attributes are checked when
1239 // the ASTContext lays out the structure.
1240 if (TUK == TUK_Definition) {
1241 AddAlignmentAttributesForRecord(NewClass);
1242 AddMsStructLayoutForRecord(NewClass);
1245 ClassTemplateDecl *NewTemplate
1246 = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc,
1247 DeclarationName(Name), TemplateParams,
1248 NewClass, PrevClassTemplate);
1249 NewClass->setDescribedClassTemplate(NewTemplate);
1251 if (ModulePrivateLoc.isValid())
1252 NewTemplate->setModulePrivate();
1254 // Build the type for the class template declaration now.
1255 QualType T = NewTemplate->getInjectedClassNameSpecialization();
1256 T = Context.getInjectedClassNameType(NewClass, T);
1257 assert(T->isDependentType() && "Class template type is not dependent?");
1260 // If we are providing an explicit specialization of a member that is a
1261 // class template, make a note of that.
1262 if (PrevClassTemplate &&
1263 PrevClassTemplate->getInstantiatedFromMemberTemplate())
1264 PrevClassTemplate->setMemberSpecialization();
1266 // Set the access specifier.
1267 if (!Invalid && TUK != TUK_Friend && NewTemplate->getDeclContext()->isRecord())
1268 SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS);
1270 // Set the lexical context of these templates
1271 NewClass->setLexicalDeclContext(CurContext);
1272 NewTemplate->setLexicalDeclContext(CurContext);
1274 if (TUK == TUK_Definition)
1275 NewClass->startDefinition();
1278 ProcessDeclAttributeList(S, NewClass, Attr);
1280 if (PrevClassTemplate)
1281 mergeDeclAttributes(NewClass, PrevClassTemplate->getTemplatedDecl());
1283 AddPushedVisibilityAttribute(NewClass);
1285 if (TUK != TUK_Friend) {
1286 // Per C++ [basic.scope.temp]p2, skip the template parameter scopes.
1288 while ((Outer->getFlags() & Scope::TemplateParamScope) != 0)
1289 Outer = Outer->getParent();
1290 PushOnScopeChains(NewTemplate, Outer);
1292 if (PrevClassTemplate && PrevClassTemplate->getAccess() != AS_none) {
1293 NewTemplate->setAccess(PrevClassTemplate->getAccess());
1294 NewClass->setAccess(PrevClassTemplate->getAccess());
1297 NewTemplate->setObjectOfFriendDecl();
1299 // Friend templates are visible in fairly strange ways.
1300 if (!CurContext->isDependentContext()) {
1301 DeclContext *DC = SemanticContext->getRedeclContext();
1302 DC->makeDeclVisibleInContext(NewTemplate);
1303 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
1304 PushOnScopeChains(NewTemplate, EnclosingScope,
1305 /* AddToContext = */ false);
1308 FriendDecl *Friend = FriendDecl::Create(
1309 Context, CurContext, NewClass->getLocation(), NewTemplate, FriendLoc);
1310 Friend->setAccess(AS_public);
1311 CurContext->addDecl(Friend);
1315 NewTemplate->setInvalidDecl();
1316 NewClass->setInvalidDecl();
1319 ActOnDocumentableDecl(NewTemplate);
1324 /// \brief Diagnose the presence of a default template argument on a
1325 /// template parameter, which is ill-formed in certain contexts.
1327 /// \returns true if the default template argument should be dropped.
1328 static bool DiagnoseDefaultTemplateArgument(Sema &S,
1329 Sema::TemplateParamListContext TPC,
1330 SourceLocation ParamLoc,
1331 SourceRange DefArgRange) {
1333 case Sema::TPC_ClassTemplate:
1334 case Sema::TPC_VarTemplate:
1335 case Sema::TPC_TypeAliasTemplate:
1338 case Sema::TPC_FunctionTemplate:
1339 case Sema::TPC_FriendFunctionTemplateDefinition:
1340 // C++ [temp.param]p9:
1341 // A default template-argument shall not be specified in a
1342 // function template declaration or a function template
1344 // If a friend function template declaration specifies a default
1345 // template-argument, that declaration shall be a definition and shall be
1346 // the only declaration of the function template in the translation unit.
1347 // (C++98/03 doesn't have this wording; see DR226).
1348 S.Diag(ParamLoc, S.getLangOpts().CPlusPlus11 ?
1349 diag::warn_cxx98_compat_template_parameter_default_in_function_template
1350 : diag::ext_template_parameter_default_in_function_template)
1354 case Sema::TPC_ClassTemplateMember:
1355 // C++0x [temp.param]p9:
1356 // A default template-argument shall not be specified in the
1357 // template-parameter-lists of the definition of a member of a
1358 // class template that appears outside of the member's class.
1359 S.Diag(ParamLoc, diag::err_template_parameter_default_template_member)
1363 case Sema::TPC_FriendClassTemplate:
1364 case Sema::TPC_FriendFunctionTemplate:
1365 // C++ [temp.param]p9:
1366 // A default template-argument shall not be specified in a
1367 // friend template declaration.
1368 S.Diag(ParamLoc, diag::err_template_parameter_default_friend_template)
1372 // FIXME: C++0x [temp.param]p9 allows default template-arguments
1373 // for friend function templates if there is only a single
1374 // declaration (and it is a definition). Strange!
1377 llvm_unreachable("Invalid TemplateParamListContext!");
1380 /// \brief Check for unexpanded parameter packs within the template parameters
1381 /// of a template template parameter, recursively.
1382 static bool DiagnoseUnexpandedParameterPacks(Sema &S,
1383 TemplateTemplateParmDecl *TTP) {
1384 // A template template parameter which is a parameter pack is also a pack
1386 if (TTP->isParameterPack())
1389 TemplateParameterList *Params = TTP->getTemplateParameters();
1390 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
1391 NamedDecl *P = Params->getParam(I);
1392 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P)) {
1393 if (!NTTP->isParameterPack() &&
1394 S.DiagnoseUnexpandedParameterPack(NTTP->getLocation(),
1395 NTTP->getTypeSourceInfo(),
1396 Sema::UPPC_NonTypeTemplateParameterType))
1402 if (TemplateTemplateParmDecl *InnerTTP
1403 = dyn_cast<TemplateTemplateParmDecl>(P))
1404 if (DiagnoseUnexpandedParameterPacks(S, InnerTTP))
1411 /// \brief Checks the validity of a template parameter list, possibly
1412 /// considering the template parameter list from a previous
1415 /// If an "old" template parameter list is provided, it must be
1416 /// equivalent (per TemplateParameterListsAreEqual) to the "new"
1417 /// template parameter list.
1419 /// \param NewParams Template parameter list for a new template
1420 /// declaration. This template parameter list will be updated with any
1421 /// default arguments that are carried through from the previous
1422 /// template parameter list.
1424 /// \param OldParams If provided, template parameter list from a
1425 /// previous declaration of the same template. Default template
1426 /// arguments will be merged from the old template parameter list to
1427 /// the new template parameter list.
1429 /// \param TPC Describes the context in which we are checking the given
1430 /// template parameter list.
1432 /// \returns true if an error occurred, false otherwise.
1433 bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
1434 TemplateParameterList *OldParams,
1435 TemplateParamListContext TPC) {
1436 bool Invalid = false;
1438 // C++ [temp.param]p10:
1439 // The set of default template-arguments available for use with a
1440 // template declaration or definition is obtained by merging the
1441 // default arguments from the definition (if in scope) and all
1442 // declarations in scope in the same way default function
1443 // arguments are (8.3.6).
1444 bool SawDefaultArgument = false;
1445 SourceLocation PreviousDefaultArgLoc;
1447 // Dummy initialization to avoid warnings.
1448 TemplateParameterList::iterator OldParam = NewParams->end();
1450 OldParam = OldParams->begin();
1452 bool RemoveDefaultArguments = false;
1453 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
1454 NewParamEnd = NewParams->end();
1455 NewParam != NewParamEnd; ++NewParam) {
1456 // Variables used to diagnose redundant default arguments
1457 bool RedundantDefaultArg = false;
1458 SourceLocation OldDefaultLoc;
1459 SourceLocation NewDefaultLoc;
1461 // Variable used to diagnose missing default arguments
1462 bool MissingDefaultArg = false;
1464 // Variable used to diagnose non-final parameter packs
1465 bool SawParameterPack = false;
1467 if (TemplateTypeParmDecl *NewTypeParm
1468 = dyn_cast<TemplateTypeParmDecl>(*NewParam)) {
1469 // Check the presence of a default argument here.
1470 if (NewTypeParm->hasDefaultArgument() &&
1471 DiagnoseDefaultTemplateArgument(*this, TPC,
1472 NewTypeParm->getLocation(),
1473 NewTypeParm->getDefaultArgumentInfo()->getTypeLoc()
1475 NewTypeParm->removeDefaultArgument();
1477 // Merge default arguments for template type parameters.
1478 TemplateTypeParmDecl *OldTypeParm
1479 = OldParams? cast<TemplateTypeParmDecl>(*OldParam) : nullptr;
1480 if (NewTypeParm->isParameterPack()) {
1481 assert(!NewTypeParm->hasDefaultArgument() &&
1482 "Parameter packs can't have a default argument!");
1483 SawParameterPack = true;
1484 } else if (OldTypeParm && hasVisibleDefaultArgument(OldTypeParm) &&
1485 NewTypeParm->hasDefaultArgument()) {
1486 OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc();
1487 NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc();
1488 SawDefaultArgument = true;
1489 RedundantDefaultArg = true;
1490 PreviousDefaultArgLoc = NewDefaultLoc;
1491 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument()) {
1492 // Merge the default argument from the old declaration to the
1494 NewTypeParm->setInheritedDefaultArgument(Context, OldTypeParm);
1495 PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc();
1496 } else if (NewTypeParm->hasDefaultArgument()) {
1497 SawDefaultArgument = true;
1498 PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc();
1499 } else if (SawDefaultArgument)
1500 MissingDefaultArg = true;
1501 } else if (NonTypeTemplateParmDecl *NewNonTypeParm
1502 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) {
1503 // Check for unexpanded parameter packs.
1504 if (!NewNonTypeParm->isParameterPack() &&
1505 DiagnoseUnexpandedParameterPack(NewNonTypeParm->getLocation(),
1506 NewNonTypeParm->getTypeSourceInfo(),
1507 UPPC_NonTypeTemplateParameterType)) {
1512 // Check the presence of a default argument here.
1513 if (NewNonTypeParm->hasDefaultArgument() &&
1514 DiagnoseDefaultTemplateArgument(*this, TPC,
1515 NewNonTypeParm->getLocation(),
1516 NewNonTypeParm->getDefaultArgument()->getSourceRange())) {
1517 NewNonTypeParm->removeDefaultArgument();
1520 // Merge default arguments for non-type template parameters
1521 NonTypeTemplateParmDecl *OldNonTypeParm
1522 = OldParams? cast<NonTypeTemplateParmDecl>(*OldParam) : nullptr;
1523 if (NewNonTypeParm->isParameterPack()) {
1524 assert(!NewNonTypeParm->hasDefaultArgument() &&
1525 "Parameter packs can't have a default argument!");
1526 if (!NewNonTypeParm->isPackExpansion())
1527 SawParameterPack = true;
1528 } else if (OldNonTypeParm && hasVisibleDefaultArgument(OldNonTypeParm) &&
1529 NewNonTypeParm->hasDefaultArgument()) {
1530 OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc();
1531 NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc();
1532 SawDefaultArgument = true;
1533 RedundantDefaultArg = true;
1534 PreviousDefaultArgLoc = NewDefaultLoc;
1535 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument()) {
1536 // Merge the default argument from the old declaration to the
1538 NewNonTypeParm->setInheritedDefaultArgument(Context, OldNonTypeParm);
1539 PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc();
1540 } else if (NewNonTypeParm->hasDefaultArgument()) {
1541 SawDefaultArgument = true;
1542 PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc();
1543 } else if (SawDefaultArgument)
1544 MissingDefaultArg = true;
1546 TemplateTemplateParmDecl *NewTemplateParm
1547 = cast<TemplateTemplateParmDecl>(*NewParam);
1549 // Check for unexpanded parameter packs, recursively.
1550 if (::DiagnoseUnexpandedParameterPacks(*this, NewTemplateParm)) {
1555 // Check the presence of a default argument here.
1556 if (NewTemplateParm->hasDefaultArgument() &&
1557 DiagnoseDefaultTemplateArgument(*this, TPC,
1558 NewTemplateParm->getLocation(),
1559 NewTemplateParm->getDefaultArgument().getSourceRange()))
1560 NewTemplateParm->removeDefaultArgument();
1562 // Merge default arguments for template template parameters
1563 TemplateTemplateParmDecl *OldTemplateParm
1564 = OldParams? cast<TemplateTemplateParmDecl>(*OldParam) : nullptr;
1565 if (NewTemplateParm->isParameterPack()) {
1566 assert(!NewTemplateParm->hasDefaultArgument() &&
1567 "Parameter packs can't have a default argument!");
1568 if (!NewTemplateParm->isPackExpansion())
1569 SawParameterPack = true;
1570 } else if (OldTemplateParm &&
1571 hasVisibleDefaultArgument(OldTemplateParm) &&
1572 NewTemplateParm->hasDefaultArgument()) {
1573 OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation();
1574 NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation();
1575 SawDefaultArgument = true;
1576 RedundantDefaultArg = true;
1577 PreviousDefaultArgLoc = NewDefaultLoc;
1578 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument()) {
1579 // Merge the default argument from the old declaration to the
1581 NewTemplateParm->setInheritedDefaultArgument(Context, OldTemplateParm);
1582 PreviousDefaultArgLoc
1583 = OldTemplateParm->getDefaultArgument().getLocation();
1584 } else if (NewTemplateParm->hasDefaultArgument()) {
1585 SawDefaultArgument = true;
1586 PreviousDefaultArgLoc
1587 = NewTemplateParm->getDefaultArgument().getLocation();
1588 } else if (SawDefaultArgument)
1589 MissingDefaultArg = true;
1592 // C++11 [temp.param]p11:
1593 // If a template parameter of a primary class template or alias template
1594 // is a template parameter pack, it shall be the last template parameter.
1595 if (SawParameterPack && (NewParam + 1) != NewParamEnd &&
1596 (TPC == TPC_ClassTemplate || TPC == TPC_VarTemplate ||
1597 TPC == TPC_TypeAliasTemplate)) {
1598 Diag((*NewParam)->getLocation(),
1599 diag::err_template_param_pack_must_be_last_template_parameter);
1603 if (RedundantDefaultArg) {
1604 // C++ [temp.param]p12:
1605 // A template-parameter shall not be given default arguments
1606 // by two different declarations in the same scope.
1607 Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition);
1608 Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg);
1610 } else if (MissingDefaultArg && TPC != TPC_FunctionTemplate) {
1611 // C++ [temp.param]p11:
1612 // If a template-parameter of a class template has a default
1613 // template-argument, each subsequent template-parameter shall either
1614 // have a default template-argument supplied or be a template parameter
1616 Diag((*NewParam)->getLocation(),
1617 diag::err_template_param_default_arg_missing);
1618 Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg);
1620 RemoveDefaultArguments = true;
1623 // If we have an old template parameter list that we're merging
1624 // in, move on to the next parameter.
1629 // We were missing some default arguments at the end of the list, so remove
1630 // all of the default arguments.
1631 if (RemoveDefaultArguments) {
1632 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
1633 NewParamEnd = NewParams->end();
1634 NewParam != NewParamEnd; ++NewParam) {
1635 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*NewParam))
1636 TTP->removeDefaultArgument();
1637 else if (NonTypeTemplateParmDecl *NTTP
1638 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam))
1639 NTTP->removeDefaultArgument();
1641 cast<TemplateTemplateParmDecl>(*NewParam)->removeDefaultArgument();
1650 /// A class which looks for a use of a certain level of template
1652 struct DependencyChecker : RecursiveASTVisitor<DependencyChecker> {
1653 typedef RecursiveASTVisitor<DependencyChecker> super;
1657 // Whether we're looking for a use of a template parameter that makes the
1658 // overall construct type-dependent / a dependent type. This is strictly
1659 // best-effort for now; we may fail to match at all for a dependent type
1660 // in some cases if this is set.
1661 bool IgnoreNonTypeDependent;
1664 SourceLocation MatchLoc;
1666 DependencyChecker(unsigned Depth, bool IgnoreNonTypeDependent)
1667 : Depth(Depth), IgnoreNonTypeDependent(IgnoreNonTypeDependent),
1670 DependencyChecker(TemplateParameterList *Params, bool IgnoreNonTypeDependent)
1671 : IgnoreNonTypeDependent(IgnoreNonTypeDependent), Match(false) {
1672 NamedDecl *ND = Params->getParam(0);
1673 if (TemplateTypeParmDecl *PD = dyn_cast<TemplateTypeParmDecl>(ND)) {
1674 Depth = PD->getDepth();
1675 } else if (NonTypeTemplateParmDecl *PD =
1676 dyn_cast<NonTypeTemplateParmDecl>(ND)) {
1677 Depth = PD->getDepth();
1679 Depth = cast<TemplateTemplateParmDecl>(ND)->getDepth();
1683 bool Matches(unsigned ParmDepth, SourceLocation Loc = SourceLocation()) {
1684 if (ParmDepth >= Depth) {
1692 bool TraverseStmt(Stmt *S, DataRecursionQueue *Q = nullptr) {
1693 // Prune out non-type-dependent expressions if requested. This can
1694 // sometimes result in us failing to find a template parameter reference
1695 // (if a value-dependent expression creates a dependent type), but this
1696 // mode is best-effort only.
1697 if (auto *E = dyn_cast_or_null<Expr>(S))
1698 if (IgnoreNonTypeDependent && !E->isTypeDependent())
1700 return super::TraverseStmt(S, Q);
1703 bool TraverseTypeLoc(TypeLoc TL) {
1704 if (IgnoreNonTypeDependent && !TL.isNull() &&
1705 !TL.getType()->isDependentType())
1707 return super::TraverseTypeLoc(TL);
1710 bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
1711 return !Matches(TL.getTypePtr()->getDepth(), TL.getNameLoc());
1714 bool VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
1715 // For a best-effort search, keep looking until we find a location.
1716 return IgnoreNonTypeDependent || !Matches(T->getDepth());
1719 bool TraverseTemplateName(TemplateName N) {
1720 if (TemplateTemplateParmDecl *PD =
1721 dyn_cast_or_null<TemplateTemplateParmDecl>(N.getAsTemplateDecl()))
1722 if (Matches(PD->getDepth()))
1724 return super::TraverseTemplateName(N);
1727 bool VisitDeclRefExpr(DeclRefExpr *E) {
1728 if (NonTypeTemplateParmDecl *PD =
1729 dyn_cast<NonTypeTemplateParmDecl>(E->getDecl()))
1730 if (Matches(PD->getDepth(), E->getExprLoc()))
1732 return super::VisitDeclRefExpr(E);
1735 bool VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *T) {
1736 return TraverseType(T->getReplacementType());
1740 VisitSubstTemplateTypeParmPackType(const SubstTemplateTypeParmPackType *T) {
1741 return TraverseTemplateArgument(T->getArgumentPack());
1744 bool TraverseInjectedClassNameType(const InjectedClassNameType *T) {
1745 return TraverseType(T->getInjectedSpecializationType());
1748 } // end anonymous namespace
1750 /// Determines whether a given type depends on the given parameter
1753 DependsOnTemplateParameters(QualType T, TemplateParameterList *Params) {
1754 DependencyChecker Checker(Params, /*IgnoreNonTypeDependent*/false);
1755 Checker.TraverseType(T);
1756 return Checker.Match;
1759 // Find the source range corresponding to the named type in the given
1760 // nested-name-specifier, if any.
1761 static SourceRange getRangeOfTypeInNestedNameSpecifier(ASTContext &Context,
1763 const CXXScopeSpec &SS) {
1764 NestedNameSpecifierLoc NNSLoc(SS.getScopeRep(), SS.location_data());
1765 while (NestedNameSpecifier *NNS = NNSLoc.getNestedNameSpecifier()) {
1766 if (const Type *CurType = NNS->getAsType()) {
1767 if (Context.hasSameUnqualifiedType(T, QualType(CurType, 0)))
1768 return NNSLoc.getTypeLoc().getSourceRange();
1772 NNSLoc = NNSLoc.getPrefix();
1775 return SourceRange();
1778 /// \brief Match the given template parameter lists to the given scope
1779 /// specifier, returning the template parameter list that applies to the
1782 /// \param DeclStartLoc the start of the declaration that has a scope
1783 /// specifier or a template parameter list.
1785 /// \param DeclLoc The location of the declaration itself.
1787 /// \param SS the scope specifier that will be matched to the given template
1788 /// parameter lists. This scope specifier precedes a qualified name that is
1791 /// \param TemplateId The template-id following the scope specifier, if there
1792 /// is one. Used to check for a missing 'template<>'.
1794 /// \param ParamLists the template parameter lists, from the outermost to the
1795 /// innermost template parameter lists.
1797 /// \param IsFriend Whether to apply the slightly different rules for
1798 /// matching template parameters to scope specifiers in friend
1801 /// \param IsExplicitSpecialization will be set true if the entity being
1802 /// declared is an explicit specialization, false otherwise.
1804 /// \returns the template parameter list, if any, that corresponds to the
1805 /// name that is preceded by the scope specifier @p SS. This template
1806 /// parameter list may have template parameters (if we're declaring a
1807 /// template) or may have no template parameters (if we're declaring a
1808 /// template specialization), or may be NULL (if what we're declaring isn't
1809 /// itself a template).
1810 TemplateParameterList *Sema::MatchTemplateParametersToScopeSpecifier(
1811 SourceLocation DeclStartLoc, SourceLocation DeclLoc, const CXXScopeSpec &SS,
1812 TemplateIdAnnotation *TemplateId,
1813 ArrayRef<TemplateParameterList *> ParamLists, bool IsFriend,
1814 bool &IsExplicitSpecialization, bool &Invalid) {
1815 IsExplicitSpecialization = false;
1818 // The sequence of nested types to which we will match up the template
1819 // parameter lists. We first build this list by starting with the type named
1820 // by the nested-name-specifier and walking out until we run out of types.
1821 SmallVector<QualType, 4> NestedTypes;
1823 if (SS.getScopeRep()) {
1824 if (CXXRecordDecl *Record
1825 = dyn_cast_or_null<CXXRecordDecl>(computeDeclContext(SS, true)))
1826 T = Context.getTypeDeclType(Record);
1828 T = QualType(SS.getScopeRep()->getAsType(), 0);
1831 // If we found an explicit specialization that prevents us from needing
1832 // 'template<>' headers, this will be set to the location of that
1833 // explicit specialization.
1834 SourceLocation ExplicitSpecLoc;
1836 while (!T.isNull()) {
1837 NestedTypes.push_back(T);
1839 // Retrieve the parent of a record type.
1840 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
1841 // If this type is an explicit specialization, we're done.
1842 if (ClassTemplateSpecializationDecl *Spec
1843 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
1844 if (!isa<ClassTemplatePartialSpecializationDecl>(Spec) &&
1845 Spec->getSpecializationKind() == TSK_ExplicitSpecialization) {
1846 ExplicitSpecLoc = Spec->getLocation();
1849 } else if (Record->getTemplateSpecializationKind()
1850 == TSK_ExplicitSpecialization) {
1851 ExplicitSpecLoc = Record->getLocation();
1855 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Record->getParent()))
1856 T = Context.getTypeDeclType(Parent);
1862 if (const TemplateSpecializationType *TST
1863 = T->getAs<TemplateSpecializationType>()) {
1864 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
1865 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Template->getDeclContext()))
1866 T = Context.getTypeDeclType(Parent);
1873 // Look one step prior in a dependent template specialization type.
1874 if (const DependentTemplateSpecializationType *DependentTST
1875 = T->getAs<DependentTemplateSpecializationType>()) {
1876 if (NestedNameSpecifier *NNS = DependentTST->getQualifier())
1877 T = QualType(NNS->getAsType(), 0);
1883 // Look one step prior in a dependent name type.
1884 if (const DependentNameType *DependentName = T->getAs<DependentNameType>()){
1885 if (NestedNameSpecifier *NNS = DependentName->getQualifier())
1886 T = QualType(NNS->getAsType(), 0);
1892 // Retrieve the parent of an enumeration type.
1893 if (const EnumType *EnumT = T->getAs<EnumType>()) {
1894 // FIXME: Forward-declared enums require a TSK_ExplicitSpecialization
1896 EnumDecl *Enum = EnumT->getDecl();
1898 // Get to the parent type.
1899 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Enum->getParent()))
1900 T = Context.getTypeDeclType(Parent);
1908 // Reverse the nested types list, since we want to traverse from the outermost
1909 // to the innermost while checking template-parameter-lists.
1910 std::reverse(NestedTypes.begin(), NestedTypes.end());
1912 // C++0x [temp.expl.spec]p17:
1913 // A member or a member template may be nested within many
1914 // enclosing class templates. In an explicit specialization for
1915 // such a member, the member declaration shall be preceded by a
1916 // template<> for each enclosing class template that is
1917 // explicitly specialized.
1918 bool SawNonEmptyTemplateParameterList = false;
1920 auto CheckExplicitSpecialization = [&](SourceRange Range, bool Recovery) {
1921 if (SawNonEmptyTemplateParameterList) {
1922 Diag(DeclLoc, diag::err_specialize_member_of_template)
1923 << !Recovery << Range;
1925 IsExplicitSpecialization = false;
1932 auto DiagnoseMissingExplicitSpecialization = [&] (SourceRange Range) {
1933 // Check that we can have an explicit specialization here.
1934 if (CheckExplicitSpecialization(Range, true))
1937 // We don't have a template header, but we should.
1938 SourceLocation ExpectedTemplateLoc;
1939 if (!ParamLists.empty())
1940 ExpectedTemplateLoc = ParamLists[0]->getTemplateLoc();
1942 ExpectedTemplateLoc = DeclStartLoc;
1944 Diag(DeclLoc, diag::err_template_spec_needs_header)
1946 << FixItHint::CreateInsertion(ExpectedTemplateLoc, "template<> ");
1950 unsigned ParamIdx = 0;
1951 for (unsigned TypeIdx = 0, NumTypes = NestedTypes.size(); TypeIdx != NumTypes;
1953 T = NestedTypes[TypeIdx];
1955 // Whether we expect a 'template<>' header.
1956 bool NeedEmptyTemplateHeader = false;
1958 // Whether we expect a template header with parameters.
1959 bool NeedNonemptyTemplateHeader = false;
1961 // For a dependent type, the set of template parameters that we
1963 TemplateParameterList *ExpectedTemplateParams = nullptr;
1965 // C++0x [temp.expl.spec]p15:
1966 // A member or a member template may be nested within many enclosing
1967 // class templates. In an explicit specialization for such a member, the
1968 // member declaration shall be preceded by a template<> for each
1969 // enclosing class template that is explicitly specialized.
1970 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
1971 if (ClassTemplatePartialSpecializationDecl *Partial
1972 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
1973 ExpectedTemplateParams = Partial->getTemplateParameters();
1974 NeedNonemptyTemplateHeader = true;
1975 } else if (Record->isDependentType()) {
1976 if (Record->getDescribedClassTemplate()) {
1977 ExpectedTemplateParams = Record->getDescribedClassTemplate()
1978 ->getTemplateParameters();
1979 NeedNonemptyTemplateHeader = true;
1981 } else if (ClassTemplateSpecializationDecl *Spec
1982 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
1983 // C++0x [temp.expl.spec]p4:
1984 // Members of an explicitly specialized class template are defined
1985 // in the same manner as members of normal classes, and not using
1986 // the template<> syntax.
1987 if (Spec->getSpecializationKind() != TSK_ExplicitSpecialization)
1988 NeedEmptyTemplateHeader = true;
1991 } else if (Record->getTemplateSpecializationKind()) {
1992 if (Record->getTemplateSpecializationKind()
1993 != TSK_ExplicitSpecialization &&
1994 TypeIdx == NumTypes - 1)
1995 IsExplicitSpecialization = true;
1999 } else if (const TemplateSpecializationType *TST
2000 = T->getAs<TemplateSpecializationType>()) {
2001 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
2002 ExpectedTemplateParams = Template->getTemplateParameters();
2003 NeedNonemptyTemplateHeader = true;
2005 } else if (T->getAs<DependentTemplateSpecializationType>()) {
2006 // FIXME: We actually could/should check the template arguments here
2007 // against the corresponding template parameter list.
2008 NeedNonemptyTemplateHeader = false;
2011 // C++ [temp.expl.spec]p16:
2012 // In an explicit specialization declaration for a member of a class
2013 // template or a member template that ap- pears in namespace scope, the
2014 // member template and some of its enclosing class templates may remain
2015 // unspecialized, except that the declaration shall not explicitly
2016 // specialize a class member template if its en- closing class templates
2017 // are not explicitly specialized as well.
2018 if (ParamIdx < ParamLists.size()) {
2019 if (ParamLists[ParamIdx]->size() == 0) {
2020 if (CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
2024 SawNonEmptyTemplateParameterList = true;
2027 if (NeedEmptyTemplateHeader) {
2028 // If we're on the last of the types, and we need a 'template<>' header
2029 // here, then it's an explicit specialization.
2030 if (TypeIdx == NumTypes - 1)
2031 IsExplicitSpecialization = true;
2033 if (ParamIdx < ParamLists.size()) {
2034 if (ParamLists[ParamIdx]->size() > 0) {
2035 // The header has template parameters when it shouldn't. Complain.
2036 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
2037 diag::err_template_param_list_matches_nontemplate)
2039 << SourceRange(ParamLists[ParamIdx]->getLAngleLoc(),
2040 ParamLists[ParamIdx]->getRAngleLoc())
2041 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
2046 // Consume this template header.
2052 if (DiagnoseMissingExplicitSpecialization(
2053 getRangeOfTypeInNestedNameSpecifier(Context, T, SS)))
2059 if (NeedNonemptyTemplateHeader) {
2060 // In friend declarations we can have template-ids which don't
2061 // depend on the corresponding template parameter lists. But
2062 // assume that empty parameter lists are supposed to match this
2064 if (IsFriend && T->isDependentType()) {
2065 if (ParamIdx < ParamLists.size() &&
2066 DependsOnTemplateParameters(T, ParamLists[ParamIdx]))
2067 ExpectedTemplateParams = nullptr;
2072 if (ParamIdx < ParamLists.size()) {
2073 // Check the template parameter list, if we can.
2074 if (ExpectedTemplateParams &&
2075 !TemplateParameterListsAreEqual(ParamLists[ParamIdx],
2076 ExpectedTemplateParams,
2077 true, TPL_TemplateMatch))
2081 CheckTemplateParameterList(ParamLists[ParamIdx], nullptr,
2082 TPC_ClassTemplateMember))
2089 Diag(DeclLoc, diag::err_template_spec_needs_template_parameters)
2091 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
2097 // If there were at least as many template-ids as there were template
2098 // parameter lists, then there are no template parameter lists remaining for
2099 // the declaration itself.
2100 if (ParamIdx >= ParamLists.size()) {
2101 if (TemplateId && !IsFriend) {
2102 // We don't have a template header for the declaration itself, but we
2104 IsExplicitSpecialization = true;
2105 DiagnoseMissingExplicitSpecialization(SourceRange(TemplateId->LAngleLoc,
2106 TemplateId->RAngleLoc));
2108 // Fabricate an empty template parameter list for the invented header.
2109 return TemplateParameterList::Create(Context, SourceLocation(),
2110 SourceLocation(), None,
2111 SourceLocation(), nullptr);
2117 // If there were too many template parameter lists, complain about that now.
2118 if (ParamIdx < ParamLists.size() - 1) {
2119 bool HasAnyExplicitSpecHeader = false;
2120 bool AllExplicitSpecHeaders = true;
2121 for (unsigned I = ParamIdx, E = ParamLists.size() - 1; I != E; ++I) {
2122 if (ParamLists[I]->size() == 0)
2123 HasAnyExplicitSpecHeader = true;
2125 AllExplicitSpecHeaders = false;
2128 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
2129 AllExplicitSpecHeaders ? diag::warn_template_spec_extra_headers
2130 : diag::err_template_spec_extra_headers)
2131 << SourceRange(ParamLists[ParamIdx]->getTemplateLoc(),
2132 ParamLists[ParamLists.size() - 2]->getRAngleLoc());
2134 // If there was a specialization somewhere, such that 'template<>' is
2135 // not required, and there were any 'template<>' headers, note where the
2136 // specialization occurred.
2137 if (ExplicitSpecLoc.isValid() && HasAnyExplicitSpecHeader)
2138 Diag(ExplicitSpecLoc,
2139 diag::note_explicit_template_spec_does_not_need_header)
2140 << NestedTypes.back();
2142 // We have a template parameter list with no corresponding scope, which
2143 // means that the resulting template declaration can't be instantiated
2144 // properly (we'll end up with dependent nodes when we shouldn't).
2145 if (!AllExplicitSpecHeaders)
2149 // C++ [temp.expl.spec]p16:
2150 // In an explicit specialization declaration for a member of a class
2151 // template or a member template that ap- pears in namespace scope, the
2152 // member template and some of its enclosing class templates may remain
2153 // unspecialized, except that the declaration shall not explicitly
2154 // specialize a class member template if its en- closing class templates
2155 // are not explicitly specialized as well.
2156 if (ParamLists.back()->size() == 0 &&
2157 CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
2161 // Return the last template parameter list, which corresponds to the
2162 // entity being declared.
2163 return ParamLists.back();
2166 void Sema::NoteAllFoundTemplates(TemplateName Name) {
2167 if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
2168 Diag(Template->getLocation(), diag::note_template_declared_here)
2169 << (isa<FunctionTemplateDecl>(Template)
2171 : isa<ClassTemplateDecl>(Template)
2173 : isa<VarTemplateDecl>(Template)
2175 : isa<TypeAliasTemplateDecl>(Template) ? 3 : 4)
2176 << Template->getDeclName();
2180 if (OverloadedTemplateStorage *OST = Name.getAsOverloadedTemplate()) {
2181 for (OverloadedTemplateStorage::iterator I = OST->begin(),
2184 Diag((*I)->getLocation(), diag::note_template_declared_here)
2185 << 0 << (*I)->getDeclName();
2192 checkBuiltinTemplateIdType(Sema &SemaRef, BuiltinTemplateDecl *BTD,
2193 const SmallVectorImpl<TemplateArgument> &Converted,
2194 SourceLocation TemplateLoc,
2195 TemplateArgumentListInfo &TemplateArgs) {
2196 ASTContext &Context = SemaRef.getASTContext();
2197 switch (BTD->getBuiltinTemplateKind()) {
2198 case BTK__make_integer_seq: {
2199 // Specializations of __make_integer_seq<S, T, N> are treated like
2200 // S<T, 0, ..., N-1>.
2202 // C++14 [inteseq.intseq]p1:
2203 // T shall be an integer type.
2204 if (!Converted[1].getAsType()->isIntegralType(Context)) {
2205 SemaRef.Diag(TemplateArgs[1].getLocation(),
2206 diag::err_integer_sequence_integral_element_type);
2210 // C++14 [inteseq.make]p1:
2211 // If N is negative the program is ill-formed.
2212 TemplateArgument NumArgsArg = Converted[2];
2213 llvm::APSInt NumArgs = NumArgsArg.getAsIntegral();
2215 SemaRef.Diag(TemplateArgs[2].getLocation(),
2216 diag::err_integer_sequence_negative_length);
2220 QualType ArgTy = NumArgsArg.getIntegralType();
2221 TemplateArgumentListInfo SyntheticTemplateArgs;
2222 // The type argument gets reused as the first template argument in the
2223 // synthetic template argument list.
2224 SyntheticTemplateArgs.addArgument(TemplateArgs[1]);
2225 // Expand N into 0 ... N-1.
2226 for (llvm::APSInt I(NumArgs.getBitWidth(), NumArgs.isUnsigned());
2228 TemplateArgument TA(Context, I, ArgTy);
2229 SyntheticTemplateArgs.addArgument(SemaRef.getTrivialTemplateArgumentLoc(
2230 TA, ArgTy, TemplateArgs[2].getLocation()));
2232 // The first template argument will be reused as the template decl that
2233 // our synthetic template arguments will be applied to.
2234 return SemaRef.CheckTemplateIdType(Converted[0].getAsTemplate(),
2235 TemplateLoc, SyntheticTemplateArgs);
2238 case BTK__type_pack_element:
2239 // Specializations of
2240 // __type_pack_element<Index, T_1, ..., T_N>
2241 // are treated like T_Index.
2242 assert(Converted.size() == 2 &&
2243 "__type_pack_element should be given an index and a parameter pack");
2245 // If the Index is out of bounds, the program is ill-formed.
2246 TemplateArgument IndexArg = Converted[0], Ts = Converted[1];
2247 llvm::APSInt Index = IndexArg.getAsIntegral();
2248 assert(Index >= 0 && "the index used with __type_pack_element should be of "
2249 "type std::size_t, and hence be non-negative");
2250 if (Index >= Ts.pack_size()) {
2251 SemaRef.Diag(TemplateArgs[0].getLocation(),
2252 diag::err_type_pack_element_out_of_bounds);
2256 // We simply return the type at index `Index`.
2257 auto Nth = std::next(Ts.pack_begin(), Index.getExtValue());
2258 return Nth->getAsType();
2260 llvm_unreachable("unexpected BuiltinTemplateDecl!");
2263 QualType Sema::CheckTemplateIdType(TemplateName Name,
2264 SourceLocation TemplateLoc,
2265 TemplateArgumentListInfo &TemplateArgs) {
2266 DependentTemplateName *DTN
2267 = Name.getUnderlying().getAsDependentTemplateName();
2268 if (DTN && DTN->isIdentifier())
2269 // When building a template-id where the template-name is dependent,
2270 // assume the template is a type template. Either our assumption is
2271 // correct, or the code is ill-formed and will be diagnosed when the
2272 // dependent name is substituted.
2273 return Context.getDependentTemplateSpecializationType(ETK_None,
2274 DTN->getQualifier(),
2275 DTN->getIdentifier(),
2278 TemplateDecl *Template = Name.getAsTemplateDecl();
2279 if (!Template || isa<FunctionTemplateDecl>(Template) ||
2280 isa<VarTemplateDecl>(Template)) {
2281 // We might have a substituted template template parameter pack. If so,
2282 // build a template specialization type for it.
2283 if (Name.getAsSubstTemplateTemplateParmPack())
2284 return Context.getTemplateSpecializationType(Name, TemplateArgs);
2286 Diag(TemplateLoc, diag::err_template_id_not_a_type)
2288 NoteAllFoundTemplates(Name);
2292 // Check that the template argument list is well-formed for this
2294 SmallVector<TemplateArgument, 4> Converted;
2295 if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs,
2301 bool InstantiationDependent = false;
2302 if (TypeAliasTemplateDecl *AliasTemplate =
2303 dyn_cast<TypeAliasTemplateDecl>(Template)) {
2304 // Find the canonical type for this type alias template specialization.
2305 TypeAliasDecl *Pattern = AliasTemplate->getTemplatedDecl();
2306 if (Pattern->isInvalidDecl())
2309 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
2312 // Only substitute for the innermost template argument list.
2313 MultiLevelTemplateArgumentList TemplateArgLists;
2314 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
2315 unsigned Depth = AliasTemplate->getTemplateParameters()->getDepth();
2316 for (unsigned I = 0; I < Depth; ++I)
2317 TemplateArgLists.addOuterTemplateArguments(None);
2319 LocalInstantiationScope Scope(*this);
2320 InstantiatingTemplate Inst(*this, TemplateLoc, Template);
2321 if (Inst.isInvalid())
2324 CanonType = SubstType(Pattern->getUnderlyingType(),
2325 TemplateArgLists, AliasTemplate->getLocation(),
2326 AliasTemplate->getDeclName());
2327 if (CanonType.isNull())
2329 } else if (Name.isDependent() ||
2330 TemplateSpecializationType::anyDependentTemplateArguments(
2331 TemplateArgs, InstantiationDependent)) {
2332 // This class template specialization is a dependent
2333 // type. Therefore, its canonical type is another class template
2334 // specialization type that contains all of the converted
2335 // arguments in canonical form. This ensures that, e.g., A<T> and
2336 // A<T, T> have identical types when A is declared as:
2338 // template<typename T, typename U = T> struct A;
2339 TemplateName CanonName = Context.getCanonicalTemplateName(Name);
2340 CanonType = Context.getTemplateSpecializationType(CanonName,
2343 // FIXME: CanonType is not actually the canonical type, and unfortunately
2344 // it is a TemplateSpecializationType that we will never use again.
2345 // In the future, we need to teach getTemplateSpecializationType to only
2346 // build the canonical type and return that to us.
2347 CanonType = Context.getCanonicalType(CanonType);
2349 // This might work out to be a current instantiation, in which
2350 // case the canonical type needs to be the InjectedClassNameType.
2352 // TODO: in theory this could be a simple hashtable lookup; most
2353 // changes to CurContext don't change the set of current
2355 if (isa<ClassTemplateDecl>(Template)) {
2356 for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) {
2357 // If we get out to a namespace, we're done.
2358 if (Ctx->isFileContext()) break;
2360 // If this isn't a record, keep looking.
2361 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx);
2362 if (!Record) continue;
2364 // Look for one of the two cases with InjectedClassNameTypes
2365 // and check whether it's the same template.
2366 if (!isa<ClassTemplatePartialSpecializationDecl>(Record) &&
2367 !Record->getDescribedClassTemplate())
2370 // Fetch the injected class name type and check whether its
2371 // injected type is equal to the type we just built.
2372 QualType ICNT = Context.getTypeDeclType(Record);
2373 QualType Injected = cast<InjectedClassNameType>(ICNT)
2374 ->getInjectedSpecializationType();
2376 if (CanonType != Injected->getCanonicalTypeInternal())
2379 // If so, the canonical type of this TST is the injected
2380 // class name type of the record we just found.
2381 assert(ICNT.isCanonical());
2386 } else if (ClassTemplateDecl *ClassTemplate
2387 = dyn_cast<ClassTemplateDecl>(Template)) {
2388 // Find the class template specialization declaration that
2389 // corresponds to these arguments.
2390 void *InsertPos = nullptr;
2391 ClassTemplateSpecializationDecl *Decl
2392 = ClassTemplate->findSpecialization(Converted, InsertPos);
2394 // This is the first time we have referenced this class template
2395 // specialization. Create the canonical declaration and add it to
2396 // the set of specializations.
2397 Decl = ClassTemplateSpecializationDecl::Create(Context,
2398 ClassTemplate->getTemplatedDecl()->getTagKind(),
2399 ClassTemplate->getDeclContext(),
2400 ClassTemplate->getTemplatedDecl()->getLocStart(),
2401 ClassTemplate->getLocation(),
2403 Converted, nullptr);
2404 ClassTemplate->AddSpecialization(Decl, InsertPos);
2405 if (ClassTemplate->isOutOfLine())
2406 Decl->setLexicalDeclContext(ClassTemplate->getLexicalDeclContext());
2409 // Diagnose uses of this specialization.
2410 (void)DiagnoseUseOfDecl(Decl, TemplateLoc);
2412 CanonType = Context.getTypeDeclType(Decl);
2413 assert(isa<RecordType>(CanonType) &&
2414 "type of non-dependent specialization is not a RecordType");
2415 } else if (auto *BTD = dyn_cast<BuiltinTemplateDecl>(Template)) {
2416 CanonType = checkBuiltinTemplateIdType(*this, BTD, Converted, TemplateLoc,
2420 // Build the fully-sugared type for this class template
2421 // specialization, which refers back to the class template
2422 // specialization we created or found.
2423 return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType);
2427 Sema::ActOnTemplateIdType(CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
2428 TemplateTy TemplateD, SourceLocation TemplateLoc,
2429 SourceLocation LAngleLoc,
2430 ASTTemplateArgsPtr TemplateArgsIn,
2431 SourceLocation RAngleLoc,
2432 bool IsCtorOrDtorName) {
2436 TemplateName Template = TemplateD.get();
2438 // Translate the parser's template argument list in our AST format.
2439 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
2440 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
2442 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
2444 = Context.getDependentTemplateSpecializationType(ETK_None,
2445 DTN->getQualifier(),
2446 DTN->getIdentifier(),
2448 // Build type-source information.
2450 DependentTemplateSpecializationTypeLoc SpecTL
2451 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
2452 SpecTL.setElaboratedKeywordLoc(SourceLocation());
2453 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
2454 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2455 SpecTL.setTemplateNameLoc(TemplateLoc);
2456 SpecTL.setLAngleLoc(LAngleLoc);
2457 SpecTL.setRAngleLoc(RAngleLoc);
2458 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
2459 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
2460 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
2463 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
2465 if (Result.isNull())
2468 // Build type-source information.
2470 TemplateSpecializationTypeLoc SpecTL
2471 = TLB.push<TemplateSpecializationTypeLoc>(Result);
2472 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2473 SpecTL.setTemplateNameLoc(TemplateLoc);
2474 SpecTL.setLAngleLoc(LAngleLoc);
2475 SpecTL.setRAngleLoc(RAngleLoc);
2476 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
2477 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
2479 // NOTE: avoid constructing an ElaboratedTypeLoc if this is a
2480 // constructor or destructor name (in such a case, the scope specifier
2481 // will be attached to the enclosing Decl or Expr node).
2482 if (SS.isNotEmpty() && !IsCtorOrDtorName) {
2483 // Create an elaborated-type-specifier containing the nested-name-specifier.
2484 Result = Context.getElaboratedType(ETK_None, SS.getScopeRep(), Result);
2485 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
2486 ElabTL.setElaboratedKeywordLoc(SourceLocation());
2487 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
2490 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
2493 TypeResult Sema::ActOnTagTemplateIdType(TagUseKind TUK,
2494 TypeSpecifierType TagSpec,
2495 SourceLocation TagLoc,
2497 SourceLocation TemplateKWLoc,
2498 TemplateTy TemplateD,
2499 SourceLocation TemplateLoc,
2500 SourceLocation LAngleLoc,
2501 ASTTemplateArgsPtr TemplateArgsIn,
2502 SourceLocation RAngleLoc) {
2503 TemplateName Template = TemplateD.get();
2505 // Translate the parser's template argument list in our AST format.
2506 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
2507 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
2509 // Determine the tag kind
2510 TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
2511 ElaboratedTypeKeyword Keyword
2512 = TypeWithKeyword::getKeywordForTagTypeKind(TagKind);
2514 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
2515 QualType T = Context.getDependentTemplateSpecializationType(Keyword,
2516 DTN->getQualifier(),
2517 DTN->getIdentifier(),
2520 // Build type-source information.
2522 DependentTemplateSpecializationTypeLoc SpecTL
2523 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
2524 SpecTL.setElaboratedKeywordLoc(TagLoc);
2525 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
2526 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2527 SpecTL.setTemplateNameLoc(TemplateLoc);
2528 SpecTL.setLAngleLoc(LAngleLoc);
2529 SpecTL.setRAngleLoc(RAngleLoc);
2530 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
2531 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
2532 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
2535 if (TypeAliasTemplateDecl *TAT =
2536 dyn_cast_or_null<TypeAliasTemplateDecl>(Template.getAsTemplateDecl())) {
2537 // C++0x [dcl.type.elab]p2:
2538 // If the identifier resolves to a typedef-name or the simple-template-id
2539 // resolves to an alias template specialization, the
2540 // elaborated-type-specifier is ill-formed.
2541 Diag(TemplateLoc, diag::err_tag_reference_non_tag)
2542 << TAT << NTK_TypeAliasTemplate << TagKind;
2543 Diag(TAT->getLocation(), diag::note_declared_at);
2546 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
2547 if (Result.isNull())
2548 return TypeResult(true);
2550 // Check the tag kind
2551 if (const RecordType *RT = Result->getAs<RecordType>()) {
2552 RecordDecl *D = RT->getDecl();
2554 IdentifierInfo *Id = D->getIdentifier();
2555 assert(Id && "templated class must have an identifier");
2557 if (!isAcceptableTagRedeclaration(D, TagKind, TUK == TUK_Definition,
2559 Diag(TagLoc, diag::err_use_with_wrong_tag)
2561 << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName());
2562 Diag(D->getLocation(), diag::note_previous_use);
2566 // Provide source-location information for the template specialization.
2568 TemplateSpecializationTypeLoc SpecTL
2569 = TLB.push<TemplateSpecializationTypeLoc>(Result);
2570 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2571 SpecTL.setTemplateNameLoc(TemplateLoc);
2572 SpecTL.setLAngleLoc(LAngleLoc);
2573 SpecTL.setRAngleLoc(RAngleLoc);
2574 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
2575 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
2577 // Construct an elaborated type containing the nested-name-specifier (if any)
2579 Result = Context.getElaboratedType(Keyword, SS.getScopeRep(), Result);
2580 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
2581 ElabTL.setElaboratedKeywordLoc(TagLoc);
2582 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
2583 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
2586 static bool CheckTemplateSpecializationScope(Sema &S, NamedDecl *Specialized,
2587 NamedDecl *PrevDecl,
2589 bool IsPartialSpecialization);
2591 static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D);
2593 static bool isTemplateArgumentTemplateParameter(
2594 const TemplateArgument &Arg, unsigned Depth, unsigned Index) {
2595 switch (Arg.getKind()) {
2596 case TemplateArgument::Null:
2597 case TemplateArgument::NullPtr:
2598 case TemplateArgument::Integral:
2599 case TemplateArgument::Declaration:
2600 case TemplateArgument::Pack:
2601 case TemplateArgument::TemplateExpansion:
2604 case TemplateArgument::Type: {
2605 QualType Type = Arg.getAsType();
2606 const TemplateTypeParmType *TPT =
2607 Arg.getAsType()->getAs<TemplateTypeParmType>();
2608 return TPT && !Type.hasQualifiers() &&
2609 TPT->getDepth() == Depth && TPT->getIndex() == Index;
2612 case TemplateArgument::Expression: {
2613 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg.getAsExpr());
2614 if (!DRE || !DRE->getDecl())
2616 const NonTypeTemplateParmDecl *NTTP =
2617 dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl());
2618 return NTTP && NTTP->getDepth() == Depth && NTTP->getIndex() == Index;
2621 case TemplateArgument::Template:
2622 const TemplateTemplateParmDecl *TTP =
2623 dyn_cast_or_null<TemplateTemplateParmDecl>(
2624 Arg.getAsTemplateOrTemplatePattern().getAsTemplateDecl());
2625 return TTP && TTP->getDepth() == Depth && TTP->getIndex() == Index;
2627 llvm_unreachable("unexpected kind of template argument");
2630 static bool isSameAsPrimaryTemplate(TemplateParameterList *Params,
2631 ArrayRef<TemplateArgument> Args) {
2632 if (Params->size() != Args.size())
2635 unsigned Depth = Params->getDepth();
2637 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
2638 TemplateArgument Arg = Args[I];
2640 // If the parameter is a pack expansion, the argument must be a pack
2641 // whose only element is a pack expansion.
2642 if (Params->getParam(I)->isParameterPack()) {
2643 if (Arg.getKind() != TemplateArgument::Pack || Arg.pack_size() != 1 ||
2644 !Arg.pack_begin()->isPackExpansion())
2646 Arg = Arg.pack_begin()->getPackExpansionPattern();
2649 if (!isTemplateArgumentTemplateParameter(Arg, Depth, I))
2656 /// Convert the parser's template argument list representation into our form.
2657 static TemplateArgumentListInfo
2658 makeTemplateArgumentListInfo(Sema &S, TemplateIdAnnotation &TemplateId) {
2659 TemplateArgumentListInfo TemplateArgs(TemplateId.LAngleLoc,
2660 TemplateId.RAngleLoc);
2661 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId.getTemplateArgs(),
2662 TemplateId.NumArgs);
2663 S.translateTemplateArguments(TemplateArgsPtr, TemplateArgs);
2664 return TemplateArgs;
2667 template<typename PartialSpecDecl>
2668 static void checkMoreSpecializedThanPrimary(Sema &S, PartialSpecDecl *Partial) {
2669 if (Partial->getDeclContext()->isDependentContext())
2672 // FIXME: Get the TDK from deduction in order to provide better diagnostics
2673 // for non-substitution-failure issues?
2674 TemplateDeductionInfo Info(Partial->getLocation());
2675 if (S.isMoreSpecializedThanPrimary(Partial, Info))
2678 auto *Template = Partial->getSpecializedTemplate();
2679 S.Diag(Partial->getLocation(),
2680 diag::ext_partial_spec_not_more_specialized_than_primary)
2681 << isa<VarTemplateDecl>(Template);
2683 if (Info.hasSFINAEDiagnostic()) {
2684 PartialDiagnosticAt Diag = {SourceLocation(),
2685 PartialDiagnostic::NullDiagnostic()};
2686 Info.takeSFINAEDiagnostic(Diag);
2687 SmallString<128> SFINAEArgString;
2688 Diag.second.EmitToString(S.getDiagnostics(), SFINAEArgString);
2690 diag::note_partial_spec_not_more_specialized_than_primary)
2694 S.Diag(Template->getLocation(), diag::note_template_decl_here);
2697 template<typename PartialSpecDecl>
2698 static void checkTemplatePartialSpecialization(Sema &S,
2699 PartialSpecDecl *Partial) {
2700 // C++1z [temp.class.spec]p8: (DR1495)
2701 // - The specialization shall be more specialized than the primary
2702 // template (14.5.5.2).
2703 checkMoreSpecializedThanPrimary(S, Partial);
2705 // C++ [temp.class.spec]p8: (DR1315)
2706 // - Each template-parameter shall appear at least once in the
2707 // template-id outside a non-deduced context.
2708 // C++1z [temp.class.spec.match]p3 (P0127R2)
2709 // If the template arguments of a partial specialization cannot be
2710 // deduced because of the structure of its template-parameter-list
2711 // and the template-id, the program is ill-formed.
2712 auto *TemplateParams = Partial->getTemplateParameters();
2713 llvm::SmallBitVector DeducibleParams(TemplateParams->size());
2714 S.MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
2715 TemplateParams->getDepth(), DeducibleParams);
2717 if (!DeducibleParams.all()) {
2718 unsigned NumNonDeducible = DeducibleParams.size() - DeducibleParams.count();
2719 S.Diag(Partial->getLocation(), diag::ext_partial_specs_not_deducible)
2720 << isa<VarTemplatePartialSpecializationDecl>(Partial)
2721 << (NumNonDeducible > 1)
2722 << SourceRange(Partial->getLocation(),
2723 Partial->getTemplateArgsAsWritten()->RAngleLoc);
2724 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) {
2725 if (!DeducibleParams[I]) {
2726 NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I));
2727 if (Param->getDeclName())
2728 S.Diag(Param->getLocation(),
2729 diag::note_partial_spec_unused_parameter)
2730 << Param->getDeclName();
2732 S.Diag(Param->getLocation(),
2733 diag::note_partial_spec_unused_parameter)
2740 void Sema::CheckTemplatePartialSpecialization(
2741 ClassTemplatePartialSpecializationDecl *Partial) {
2742 checkTemplatePartialSpecialization(*this, Partial);
2745 void Sema::CheckTemplatePartialSpecialization(
2746 VarTemplatePartialSpecializationDecl *Partial) {
2747 checkTemplatePartialSpecialization(*this, Partial);
2750 DeclResult Sema::ActOnVarTemplateSpecialization(
2751 Scope *S, Declarator &D, TypeSourceInfo *DI, SourceLocation TemplateKWLoc,
2752 TemplateParameterList *TemplateParams, StorageClass SC,
2753 bool IsPartialSpecialization) {
2754 // D must be variable template id.
2755 assert(D.getName().getKind() == UnqualifiedId::IK_TemplateId &&
2756 "Variable template specialization is declared with a template it.");
2758 TemplateIdAnnotation *TemplateId = D.getName().TemplateId;
2759 TemplateArgumentListInfo TemplateArgs =
2760 makeTemplateArgumentListInfo(*this, *TemplateId);
2761 SourceLocation TemplateNameLoc = D.getIdentifierLoc();
2762 SourceLocation LAngleLoc = TemplateId->LAngleLoc;
2763 SourceLocation RAngleLoc = TemplateId->RAngleLoc;
2765 TemplateName Name = TemplateId->Template.get();
2767 // The template-id must name a variable template.
2768 VarTemplateDecl *VarTemplate =
2769 dyn_cast_or_null<VarTemplateDecl>(Name.getAsTemplateDecl());
2771 NamedDecl *FnTemplate;
2772 if (auto *OTS = Name.getAsOverloadedTemplate())
2773 FnTemplate = *OTS->begin();
2775 FnTemplate = dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl());
2777 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template_but_method)
2778 << FnTemplate->getDeclName();
2779 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template)
2780 << IsPartialSpecialization;
2783 // Check for unexpanded parameter packs in any of the template arguments.
2784 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2785 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
2786 UPPC_PartialSpecialization))
2789 // Check that the template argument list is well-formed for this
2791 SmallVector<TemplateArgument, 4> Converted;
2792 if (CheckTemplateArgumentList(VarTemplate, TemplateNameLoc, TemplateArgs,
2796 // Find the variable template (partial) specialization declaration that
2797 // corresponds to these arguments.
2798 if (IsPartialSpecialization) {
2799 if (CheckTemplatePartialSpecializationArgs(TemplateNameLoc, VarTemplate,
2800 TemplateArgs.size(), Converted))
2803 // FIXME: Move these checks to CheckTemplatePartialSpecializationArgs so we
2804 // also do them during instantiation.
2805 bool InstantiationDependent;
2806 if (!Name.isDependent() &&
2807 !TemplateSpecializationType::anyDependentTemplateArguments(
2808 TemplateArgs.arguments(),
2809 InstantiationDependent)) {
2810 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
2811 << VarTemplate->getDeclName();
2812 IsPartialSpecialization = false;
2815 if (isSameAsPrimaryTemplate(VarTemplate->getTemplateParameters(),
2817 // C++ [temp.class.spec]p9b3:
2819 // -- The argument list of the specialization shall not be identical
2820 // to the implicit argument list of the primary template.
2821 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
2822 << /*variable template*/ 1
2823 << /*is definition*/(SC != SC_Extern && !CurContext->isRecord())
2824 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
2825 // FIXME: Recover from this by treating the declaration as a redeclaration
2826 // of the primary template.
2831 void *InsertPos = nullptr;
2832 VarTemplateSpecializationDecl *PrevDecl = nullptr;
2834 if (IsPartialSpecialization)
2835 // FIXME: Template parameter list matters too
2836 PrevDecl = VarTemplate->findPartialSpecialization(Converted, InsertPos);
2838 PrevDecl = VarTemplate->findSpecialization(Converted, InsertPos);
2840 VarTemplateSpecializationDecl *Specialization = nullptr;
2842 // Check whether we can declare a variable template specialization in
2843 // the current scope.
2844 if (CheckTemplateSpecializationScope(*this, VarTemplate, PrevDecl,
2846 IsPartialSpecialization))
2849 if (PrevDecl && PrevDecl->getSpecializationKind() == TSK_Undeclared) {
2850 // Since the only prior variable template specialization with these
2851 // arguments was referenced but not declared, reuse that
2852 // declaration node as our own, updating its source location and
2853 // the list of outer template parameters to reflect our new declaration.
2854 Specialization = PrevDecl;
2855 Specialization->setLocation(TemplateNameLoc);
2857 } else if (IsPartialSpecialization) {
2858 // Create a new class template partial specialization declaration node.
2859 VarTemplatePartialSpecializationDecl *PrevPartial =
2860 cast_or_null<VarTemplatePartialSpecializationDecl>(PrevDecl);
2861 VarTemplatePartialSpecializationDecl *Partial =
2862 VarTemplatePartialSpecializationDecl::Create(
2863 Context, VarTemplate->getDeclContext(), TemplateKWLoc,
2864 TemplateNameLoc, TemplateParams, VarTemplate, DI->getType(), DI, SC,
2865 Converted, TemplateArgs);
2868 VarTemplate->AddPartialSpecialization(Partial, InsertPos);
2869 Specialization = Partial;
2871 // If we are providing an explicit specialization of a member variable
2872 // template specialization, make a note of that.
2873 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
2874 PrevPartial->setMemberSpecialization();
2876 CheckTemplatePartialSpecialization(Partial);
2878 // Create a new class template specialization declaration node for
2879 // this explicit specialization or friend declaration.
2880 Specialization = VarTemplateSpecializationDecl::Create(
2881 Context, VarTemplate->getDeclContext(), TemplateKWLoc, TemplateNameLoc,
2882 VarTemplate, DI->getType(), DI, SC, Converted);
2883 Specialization->setTemplateArgsInfo(TemplateArgs);
2886 VarTemplate->AddSpecialization(Specialization, InsertPos);
2889 // C++ [temp.expl.spec]p6:
2890 // If a template, a member template or the member of a class template is
2891 // explicitly specialized then that specialization shall be declared
2892 // before the first use of that specialization that would cause an implicit
2893 // instantiation to take place, in every translation unit in which such a
2894 // use occurs; no diagnostic is required.
2895 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
2897 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
2898 // Is there any previous explicit specialization declaration?
2899 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
2906 SourceRange Range(TemplateNameLoc, RAngleLoc);
2907 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
2910 Diag(PrevDecl->getPointOfInstantiation(),
2911 diag::note_instantiation_required_here)
2912 << (PrevDecl->getTemplateSpecializationKind() !=
2913 TSK_ImplicitInstantiation);
2918 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
2919 Specialization->setLexicalDeclContext(CurContext);
2921 // Add the specialization into its lexical context, so that it can
2922 // be seen when iterating through the list of declarations in that
2923 // context. However, specializations are not found by name lookup.
2924 CurContext->addDecl(Specialization);
2926 // Note that this is an explicit specialization.
2927 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
2930 // Check that this isn't a redefinition of this specialization,
2931 // merging with previous declarations.
2932 LookupResult PrevSpec(*this, GetNameForDeclarator(D), LookupOrdinaryName,
2934 PrevSpec.addDecl(PrevDecl);
2935 D.setRedeclaration(CheckVariableDeclaration(Specialization, PrevSpec));
2936 } else if (Specialization->isStaticDataMember() &&
2937 Specialization->isOutOfLine()) {
2938 Specialization->setAccess(VarTemplate->getAccess());
2941 // Link instantiations of static data members back to the template from
2942 // which they were instantiated.
2943 if (Specialization->isStaticDataMember())
2944 Specialization->setInstantiationOfStaticDataMember(
2945 VarTemplate->getTemplatedDecl(),
2946 Specialization->getSpecializationKind());
2948 return Specialization;
2952 /// \brief A partial specialization whose template arguments have matched
2953 /// a given template-id.
2954 struct PartialSpecMatchResult {
2955 VarTemplatePartialSpecializationDecl *Partial;
2956 TemplateArgumentList *Args;
2958 } // end anonymous namespace
2961 Sema::CheckVarTemplateId(VarTemplateDecl *Template, SourceLocation TemplateLoc,
2962 SourceLocation TemplateNameLoc,
2963 const TemplateArgumentListInfo &TemplateArgs) {
2964 assert(Template && "A variable template id without template?");
2966 // Check that the template argument list is well-formed for this template.
2967 SmallVector<TemplateArgument, 4> Converted;
2968 if (CheckTemplateArgumentList(
2969 Template, TemplateNameLoc,
2970 const_cast<TemplateArgumentListInfo &>(TemplateArgs), false,
2974 // Find the variable template specialization declaration that
2975 // corresponds to these arguments.
2976 void *InsertPos = nullptr;
2977 if (VarTemplateSpecializationDecl *Spec = Template->findSpecialization(
2978 Converted, InsertPos)) {
2979 checkSpecializationVisibility(TemplateNameLoc, Spec);
2980 // If we already have a variable template specialization, return it.
2984 // This is the first time we have referenced this variable template
2985 // specialization. Create the canonical declaration and add it to
2986 // the set of specializations, based on the closest partial specialization
2987 // that it represents. That is,
2988 VarDecl *InstantiationPattern = Template->getTemplatedDecl();
2989 TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack,
2991 TemplateArgumentList *InstantiationArgs = &TemplateArgList;
2992 bool AmbiguousPartialSpec = false;
2993 typedef PartialSpecMatchResult MatchResult;
2994 SmallVector<MatchResult, 4> Matched;
2995 SourceLocation PointOfInstantiation = TemplateNameLoc;
2996 TemplateSpecCandidateSet FailedCandidates(PointOfInstantiation,
2997 /*ForTakingAddress=*/false);
2999 // 1. Attempt to find the closest partial specialization that this
3000 // specializes, if any.
3001 // If any of the template arguments is dependent, then this is probably
3002 // a placeholder for an incomplete declarative context; which must be
3003 // complete by instantiation time. Thus, do not search through the partial
3004 // specializations yet.
3005 // TODO: Unify with InstantiateClassTemplateSpecialization()?
3006 // Perhaps better after unification of DeduceTemplateArguments() and
3007 // getMoreSpecializedPartialSpecialization().
3008 bool InstantiationDependent = false;
3009 if (!TemplateSpecializationType::anyDependentTemplateArguments(
3010 TemplateArgs, InstantiationDependent)) {
3012 SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
3013 Template->getPartialSpecializations(PartialSpecs);
3015 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) {
3016 VarTemplatePartialSpecializationDecl *Partial = PartialSpecs[I];
3017 TemplateDeductionInfo Info(FailedCandidates.getLocation());
3019 if (TemplateDeductionResult Result =
3020 DeduceTemplateArguments(Partial, TemplateArgList, Info)) {
3021 // Store the failed-deduction information for use in diagnostics, later.
3022 // TODO: Actually use the failed-deduction info?
3023 FailedCandidates.addCandidate().set(
3024 DeclAccessPair::make(Template, AS_public), Partial,
3025 MakeDeductionFailureInfo(Context, Result, Info));
3028 Matched.push_back(PartialSpecMatchResult());
3029 Matched.back().Partial = Partial;
3030 Matched.back().Args = Info.take();
3034 if (Matched.size() >= 1) {
3035 SmallVector<MatchResult, 4>::iterator Best = Matched.begin();
3036 if (Matched.size() == 1) {
3037 // -- If exactly one matching specialization is found, the
3038 // instantiation is generated from that specialization.
3039 // We don't need to do anything for this.
3041 // -- If more than one matching specialization is found, the
3042 // partial order rules (14.5.4.2) are used to determine
3043 // whether one of the specializations is more specialized
3044 // than the others. If none of the specializations is more
3045 // specialized than all of the other matching
3046 // specializations, then the use of the variable template is
3047 // ambiguous and the program is ill-formed.
3048 for (SmallVector<MatchResult, 4>::iterator P = Best + 1,
3049 PEnd = Matched.end();
3051 if (getMoreSpecializedPartialSpecialization(P->Partial, Best->Partial,
3052 PointOfInstantiation) ==
3057 // Determine if the best partial specialization is more specialized than
3059 for (SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
3060 PEnd = Matched.end();
3062 if (P != Best && getMoreSpecializedPartialSpecialization(
3063 P->Partial, Best->Partial,
3064 PointOfInstantiation) != Best->Partial) {
3065 AmbiguousPartialSpec = true;
3071 // Instantiate using the best variable template partial specialization.
3072 InstantiationPattern = Best->Partial;
3073 InstantiationArgs = Best->Args;
3075 // -- If no match is found, the instantiation is generated
3076 // from the primary template.
3077 // InstantiationPattern = Template->getTemplatedDecl();
3081 // 2. Create the canonical declaration.
3082 // Note that we do not instantiate a definition until we see an odr-use
3083 // in DoMarkVarDeclReferenced().
3084 // FIXME: LateAttrs et al.?
3085 VarTemplateSpecializationDecl *Decl = BuildVarTemplateInstantiation(
3086 Template, InstantiationPattern, *InstantiationArgs, TemplateArgs,
3087 Converted, TemplateNameLoc, InsertPos /*, LateAttrs, StartingScope*/);
3091 if (AmbiguousPartialSpec) {
3092 // Partial ordering did not produce a clear winner. Complain.
3093 Decl->setInvalidDecl();
3094 Diag(PointOfInstantiation, diag::err_partial_spec_ordering_ambiguous)
3097 // Print the matching partial specializations.
3098 for (MatchResult P : Matched)
3099 Diag(P.Partial->getLocation(), diag::note_partial_spec_match)
3100 << getTemplateArgumentBindingsText(P.Partial->getTemplateParameters(),
3105 if (VarTemplatePartialSpecializationDecl *D =
3106 dyn_cast<VarTemplatePartialSpecializationDecl>(InstantiationPattern))
3107 Decl->setInstantiationOf(D, InstantiationArgs);
3109 checkSpecializationVisibility(TemplateNameLoc, Decl);
3111 assert(Decl && "No variable template specialization?");
3116 Sema::CheckVarTemplateId(const CXXScopeSpec &SS,
3117 const DeclarationNameInfo &NameInfo,
3118 VarTemplateDecl *Template, SourceLocation TemplateLoc,
3119 const TemplateArgumentListInfo *TemplateArgs) {
3121 DeclResult Decl = CheckVarTemplateId(Template, TemplateLoc, NameInfo.getLoc(),
3123 if (Decl.isInvalid())
3126 VarDecl *Var = cast<VarDecl>(Decl.get());
3127 if (!Var->getTemplateSpecializationKind())
3128 Var->setTemplateSpecializationKind(TSK_ImplicitInstantiation,
3131 // Build an ordinary singleton decl ref.
3132 return BuildDeclarationNameExpr(SS, NameInfo, Var,
3133 /*FoundD=*/nullptr, TemplateArgs);
3136 ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS,
3137 SourceLocation TemplateKWLoc,
3140 const TemplateArgumentListInfo *TemplateArgs) {
3141 // FIXME: Can we do any checking at this point? I guess we could check the
3142 // template arguments that we have against the template name, if the template
3143 // name refers to a single template. That's not a terribly common case,
3145 // foo<int> could identify a single function unambiguously
3146 // This approach does NOT work, since f<int>(1);
3147 // gets resolved prior to resorting to overload resolution
3148 // i.e., template<class T> void f(double);
3149 // vs template<class T, class U> void f(U);
3151 // These should be filtered out by our callers.
3152 assert(!R.empty() && "empty lookup results when building templateid");
3153 assert(!R.isAmbiguous() && "ambiguous lookup when building templateid");
3155 // In C++1y, check variable template ids.
3156 bool InstantiationDependent;
3157 if (R.getAsSingle<VarTemplateDecl>() &&
3158 !TemplateSpecializationType::anyDependentTemplateArguments(
3159 *TemplateArgs, InstantiationDependent)) {
3160 return CheckVarTemplateId(SS, R.getLookupNameInfo(),
3161 R.getAsSingle<VarTemplateDecl>(),
3162 TemplateKWLoc, TemplateArgs);
3165 // We don't want lookup warnings at this point.
3166 R.suppressDiagnostics();
3168 UnresolvedLookupExpr *ULE
3169 = UnresolvedLookupExpr::Create(Context, R.getNamingClass(),
3170 SS.getWithLocInContext(Context),
3172 R.getLookupNameInfo(),
3173 RequiresADL, TemplateArgs,
3174 R.begin(), R.end());
3179 // We actually only call this from template instantiation.
3181 Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS,
3182 SourceLocation TemplateKWLoc,
3183 const DeclarationNameInfo &NameInfo,
3184 const TemplateArgumentListInfo *TemplateArgs) {
3186 assert(TemplateArgs || TemplateKWLoc.isValid());
3188 if (!(DC = computeDeclContext(SS, false)) ||
3189 DC->isDependentContext() ||
3190 RequireCompleteDeclContext(SS, DC))
3191 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
3193 bool MemberOfUnknownSpecialization;
3194 LookupResult R(*this, NameInfo, LookupOrdinaryName);
3195 LookupTemplateName(R, (Scope*)nullptr, SS, QualType(), /*Entering*/ false,
3196 MemberOfUnknownSpecialization);
3198 if (R.isAmbiguous())
3202 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_non_template)
3203 << NameInfo.getName() << SS.getRange();
3207 if (ClassTemplateDecl *Temp = R.getAsSingle<ClassTemplateDecl>()) {
3208 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_class_template)
3210 << NameInfo.getName().getAsString() << SS.getRange();
3211 Diag(Temp->getLocation(), diag::note_referenced_class_template);
3215 return BuildTemplateIdExpr(SS, TemplateKWLoc, R, /*ADL*/ false, TemplateArgs);
3218 /// \brief Form a dependent template name.
3220 /// This action forms a dependent template name given the template
3221 /// name and its (presumably dependent) scope specifier. For
3222 /// example, given "MetaFun::template apply", the scope specifier \p
3223 /// SS will be "MetaFun::", \p TemplateKWLoc contains the location
3224 /// of the "template" keyword, and "apply" is the \p Name.
3225 TemplateNameKind Sema::ActOnDependentTemplateName(Scope *S,
3227 SourceLocation TemplateKWLoc,
3228 UnqualifiedId &Name,
3229 ParsedType ObjectType,
3230 bool EnteringContext,
3231 TemplateTy &Result) {
3232 if (TemplateKWLoc.isValid() && S && !S->getTemplateParamParent())
3234 getLangOpts().CPlusPlus11 ?
3235 diag::warn_cxx98_compat_template_outside_of_template :
3236 diag::ext_template_outside_of_template)
3237 << FixItHint::CreateRemoval(TemplateKWLoc);
3239 DeclContext *LookupCtx = nullptr;
3241 LookupCtx = computeDeclContext(SS, EnteringContext);
3242 if (!LookupCtx && ObjectType)
3243 LookupCtx = computeDeclContext(ObjectType.get());
3245 // C++0x [temp.names]p5:
3246 // If a name prefixed by the keyword template is not the name of
3247 // a template, the program is ill-formed. [Note: the keyword
3248 // template may not be applied to non-template members of class
3249 // templates. -end note ] [ Note: as is the case with the
3250 // typename prefix, the template prefix is allowed in cases
3251 // where it is not strictly necessary; i.e., when the
3252 // nested-name-specifier or the expression on the left of the ->
3253 // or . is not dependent on a template-parameter, or the use
3254 // does not appear in the scope of a template. -end note]
3256 // Note: C++03 was more strict here, because it banned the use of
3257 // the "template" keyword prior to a template-name that was not a
3258 // dependent name. C++ DR468 relaxed this requirement (the
3259 // "template" keyword is now permitted). We follow the C++0x
3260 // rules, even in C++03 mode with a warning, retroactively applying the DR.
3261 bool MemberOfUnknownSpecialization;
3262 TemplateNameKind TNK = isTemplateName(S, SS, TemplateKWLoc.isValid(), Name,
3263 ObjectType, EnteringContext, Result,
3264 MemberOfUnknownSpecialization);
3265 if (TNK == TNK_Non_template && LookupCtx->isDependentContext() &&
3266 isa<CXXRecordDecl>(LookupCtx) &&
3267 (!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() ||
3268 cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases())) {
3269 // This is a dependent template. Handle it below.
3270 } else if (TNK == TNK_Non_template) {
3271 Diag(Name.getLocStart(),
3272 diag::err_template_kw_refers_to_non_template)
3273 << GetNameFromUnqualifiedId(Name).getName()
3274 << Name.getSourceRange()
3276 return TNK_Non_template;
3278 // We found something; return it.
3283 NestedNameSpecifier *Qualifier = SS.getScopeRep();
3285 switch (Name.getKind()) {
3286 case UnqualifiedId::IK_Identifier:
3287 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier,
3289 return TNK_Dependent_template_name;
3291 case UnqualifiedId::IK_OperatorFunctionId:
3292 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier,
3293 Name.OperatorFunctionId.Operator));
3294 return TNK_Function_template;
3296 case UnqualifiedId::IK_LiteralOperatorId:
3297 llvm_unreachable("literal operator id cannot have a dependent scope");
3303 Diag(Name.getLocStart(),
3304 diag::err_template_kw_refers_to_non_template)
3305 << GetNameFromUnqualifiedId(Name).getName()
3306 << Name.getSourceRange()
3308 return TNK_Non_template;
3311 bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param,
3312 TemplateArgumentLoc &AL,
3313 SmallVectorImpl<TemplateArgument> &Converted) {
3314 const TemplateArgument &Arg = AL.getArgument();
3316 TypeSourceInfo *TSI = nullptr;
3318 // Check template type parameter.
3319 switch(Arg.getKind()) {
3320 case TemplateArgument::Type:
3321 // C++ [temp.arg.type]p1:
3322 // A template-argument for a template-parameter which is a
3323 // type shall be a type-id.
3324 ArgType = Arg.getAsType();
3325 TSI = AL.getTypeSourceInfo();
3327 case TemplateArgument::Template: {
3328 // We have a template type parameter but the template argument
3329 // is a template without any arguments.
3330 SourceRange SR = AL.getSourceRange();
3331 TemplateName Name = Arg.getAsTemplate();
3332 Diag(SR.getBegin(), diag::err_template_missing_args)
3334 if (TemplateDecl *Decl = Name.getAsTemplateDecl())
3335 Diag(Decl->getLocation(), diag::note_template_decl_here);
3339 case TemplateArgument::Expression: {
3340 // We have a template type parameter but the template argument is an
3341 // expression; see if maybe it is missing the "typename" keyword.
3343 DeclarationNameInfo NameInfo;
3345 if (DeclRefExpr *ArgExpr = dyn_cast<DeclRefExpr>(Arg.getAsExpr())) {
3346 SS.Adopt(ArgExpr->getQualifierLoc());
3347 NameInfo = ArgExpr->getNameInfo();
3348 } else if (DependentScopeDeclRefExpr *ArgExpr =
3349 dyn_cast<DependentScopeDeclRefExpr>(Arg.getAsExpr())) {
3350 SS.Adopt(ArgExpr->getQualifierLoc());
3351 NameInfo = ArgExpr->getNameInfo();
3352 } else if (CXXDependentScopeMemberExpr *ArgExpr =
3353 dyn_cast<CXXDependentScopeMemberExpr>(Arg.getAsExpr())) {
3354 if (ArgExpr->isImplicitAccess()) {
3355 SS.Adopt(ArgExpr->getQualifierLoc());
3356 NameInfo = ArgExpr->getMemberNameInfo();
3360 if (auto *II = NameInfo.getName().getAsIdentifierInfo()) {
3361 LookupResult Result(*this, NameInfo, LookupOrdinaryName);
3362 LookupParsedName(Result, CurScope, &SS);
3364 if (Result.getAsSingle<TypeDecl>() ||
3365 Result.getResultKind() ==
3366 LookupResult::NotFoundInCurrentInstantiation) {
3367 // Suggest that the user add 'typename' before the NNS.
3368 SourceLocation Loc = AL.getSourceRange().getBegin();
3369 Diag(Loc, getLangOpts().MSVCCompat
3370 ? diag::ext_ms_template_type_arg_missing_typename
3371 : diag::err_template_arg_must_be_type_suggest)
3372 << FixItHint::CreateInsertion(Loc, "typename ");
3373 Diag(Param->getLocation(), diag::note_template_param_here);
3375 // Recover by synthesizing a type using the location information that we
3378 Context.getDependentNameType(ETK_Typename, SS.getScopeRep(), II);
3380 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(ArgType);
3381 TL.setElaboratedKeywordLoc(SourceLocation(/*synthesized*/));
3382 TL.setQualifierLoc(SS.getWithLocInContext(Context));
3383 TL.setNameLoc(NameInfo.getLoc());
3384 TSI = TLB.getTypeSourceInfo(Context, ArgType);
3386 // Overwrite our input TemplateArgumentLoc so that we can recover
3388 AL = TemplateArgumentLoc(TemplateArgument(ArgType),
3389 TemplateArgumentLocInfo(TSI));
3397 // We have a template type parameter but the template argument
3399 SourceRange SR = AL.getSourceRange();
3400 Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR;
3401 Diag(Param->getLocation(), diag::note_template_param_here);
3407 if (CheckTemplateArgument(Param, TSI))
3410 // Add the converted template type argument.
3411 ArgType = Context.getCanonicalType(ArgType);
3414 // If an explicitly-specified template argument type is a lifetime type
3415 // with no lifetime qualifier, the __strong lifetime qualifier is inferred.
3416 if (getLangOpts().ObjCAutoRefCount &&
3417 ArgType->isObjCLifetimeType() &&
3418 !ArgType.getObjCLifetime()) {
3420 Qs.setObjCLifetime(Qualifiers::OCL_Strong);
3421 ArgType = Context.getQualifiedType(ArgType, Qs);
3424 Converted.push_back(TemplateArgument(ArgType));
3428 /// \brief Substitute template arguments into the default template argument for
3429 /// the given template type parameter.
3431 /// \param SemaRef the semantic analysis object for which we are performing
3432 /// the substitution.
3434 /// \param Template the template that we are synthesizing template arguments
3437 /// \param TemplateLoc the location of the template name that started the
3438 /// template-id we are checking.
3440 /// \param RAngleLoc the location of the right angle bracket ('>') that
3441 /// terminates the template-id.
3443 /// \param Param the template template parameter whose default we are
3444 /// substituting into.
3446 /// \param Converted the list of template arguments provided for template
3447 /// parameters that precede \p Param in the template parameter list.
3448 /// \returns the substituted template argument, or NULL if an error occurred.
3449 static TypeSourceInfo *
3450 SubstDefaultTemplateArgument(Sema &SemaRef,
3451 TemplateDecl *Template,
3452 SourceLocation TemplateLoc,
3453 SourceLocation RAngleLoc,
3454 TemplateTypeParmDecl *Param,
3455 SmallVectorImpl<TemplateArgument> &Converted) {
3456 TypeSourceInfo *ArgType = Param->getDefaultArgumentInfo();
3458 // If the argument type is dependent, instantiate it now based
3459 // on the previously-computed template arguments.
3460 if (ArgType->getType()->isDependentType()) {
3461 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
3462 Param, Template, Converted,
3463 SourceRange(TemplateLoc, RAngleLoc));
3464 if (Inst.isInvalid())
3467 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
3469 // Only substitute for the innermost template argument list.
3470 MultiLevelTemplateArgumentList TemplateArgLists;
3471 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3472 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3473 TemplateArgLists.addOuterTemplateArguments(None);
3475 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
3477 SemaRef.SubstType(ArgType, TemplateArgLists,
3478 Param->getDefaultArgumentLoc(), Param->getDeclName());
3484 /// \brief Substitute template arguments into the default template argument for
3485 /// the given non-type template parameter.
3487 /// \param SemaRef the semantic analysis object for which we are performing
3488 /// the substitution.
3490 /// \param Template the template that we are synthesizing template arguments
3493 /// \param TemplateLoc the location of the template name that started the
3494 /// template-id we are checking.
3496 /// \param RAngleLoc the location of the right angle bracket ('>') that
3497 /// terminates the template-id.
3499 /// \param Param the non-type template parameter whose default we are
3500 /// substituting into.
3502 /// \param Converted the list of template arguments provided for template
3503 /// parameters that precede \p Param in the template parameter list.
3505 /// \returns the substituted template argument, or NULL if an error occurred.
3507 SubstDefaultTemplateArgument(Sema &SemaRef,
3508 TemplateDecl *Template,
3509 SourceLocation TemplateLoc,
3510 SourceLocation RAngleLoc,
3511 NonTypeTemplateParmDecl *Param,
3512 SmallVectorImpl<TemplateArgument> &Converted) {
3513 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
3514 Param, Template, Converted,
3515 SourceRange(TemplateLoc, RAngleLoc));
3516 if (Inst.isInvalid())
3519 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
3521 // Only substitute for the innermost template argument list.
3522 MultiLevelTemplateArgumentList TemplateArgLists;
3523 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3524 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3525 TemplateArgLists.addOuterTemplateArguments(None);
3527 EnterExpressionEvaluationContext ConstantEvaluated(SemaRef,
3528 Sema::ConstantEvaluated);
3529 return SemaRef.SubstExpr(Param->getDefaultArgument(), TemplateArgLists);
3532 /// \brief Substitute template arguments into the default template argument for
3533 /// the given template template parameter.
3535 /// \param SemaRef the semantic analysis object for which we are performing
3536 /// the substitution.
3538 /// \param Template the template that we are synthesizing template arguments
3541 /// \param TemplateLoc the location of the template name that started the
3542 /// template-id we are checking.
3544 /// \param RAngleLoc the location of the right angle bracket ('>') that
3545 /// terminates the template-id.
3547 /// \param Param the template template parameter whose default we are
3548 /// substituting into.
3550 /// \param Converted the list of template arguments provided for template
3551 /// parameters that precede \p Param in the template parameter list.
3553 /// \param QualifierLoc Will be set to the nested-name-specifier (with
3554 /// source-location information) that precedes the template name.
3556 /// \returns the substituted template argument, or NULL if an error occurred.
3558 SubstDefaultTemplateArgument(Sema &SemaRef,
3559 TemplateDecl *Template,
3560 SourceLocation TemplateLoc,
3561 SourceLocation RAngleLoc,
3562 TemplateTemplateParmDecl *Param,
3563 SmallVectorImpl<TemplateArgument> &Converted,
3564 NestedNameSpecifierLoc &QualifierLoc) {
3565 Sema::InstantiatingTemplate Inst(
3566 SemaRef, TemplateLoc, TemplateParameter(Param), Template, Converted,
3567 SourceRange(TemplateLoc, RAngleLoc));
3568 if (Inst.isInvalid())
3569 return TemplateName();
3571 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
3573 // Only substitute for the innermost template argument list.
3574 MultiLevelTemplateArgumentList TemplateArgLists;
3575 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3576 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3577 TemplateArgLists.addOuterTemplateArguments(None);
3579 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
3580 // Substitute into the nested-name-specifier first,
3581 QualifierLoc = Param->getDefaultArgument().getTemplateQualifierLoc();
3584 SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgLists);
3586 return TemplateName();
3589 return SemaRef.SubstTemplateName(
3591 Param->getDefaultArgument().getArgument().getAsTemplate(),
3592 Param->getDefaultArgument().getTemplateNameLoc(),
3596 /// \brief If the given template parameter has a default template
3597 /// argument, substitute into that default template argument and
3598 /// return the corresponding template argument.
3600 Sema::SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template,
3601 SourceLocation TemplateLoc,
3602 SourceLocation RAngleLoc,
3604 SmallVectorImpl<TemplateArgument>
3606 bool &HasDefaultArg) {
3607 HasDefaultArg = false;
3609 if (TemplateTypeParmDecl *TypeParm = dyn_cast<TemplateTypeParmDecl>(Param)) {
3610 if (!hasVisibleDefaultArgument(TypeParm))
3611 return TemplateArgumentLoc();
3613 HasDefaultArg = true;
3614 TypeSourceInfo *DI = SubstDefaultTemplateArgument(*this, Template,
3620 return TemplateArgumentLoc(TemplateArgument(DI->getType()), DI);
3622 return TemplateArgumentLoc();
3625 if (NonTypeTemplateParmDecl *NonTypeParm
3626 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3627 if (!hasVisibleDefaultArgument(NonTypeParm))
3628 return TemplateArgumentLoc();
3630 HasDefaultArg = true;
3631 ExprResult Arg = SubstDefaultTemplateArgument(*this, Template,
3636 if (Arg.isInvalid())
3637 return TemplateArgumentLoc();
3639 Expr *ArgE = Arg.getAs<Expr>();
3640 return TemplateArgumentLoc(TemplateArgument(ArgE), ArgE);
3643 TemplateTemplateParmDecl *TempTempParm
3644 = cast<TemplateTemplateParmDecl>(Param);
3645 if (!hasVisibleDefaultArgument(TempTempParm))
3646 return TemplateArgumentLoc();
3648 HasDefaultArg = true;
3649 NestedNameSpecifierLoc QualifierLoc;
3650 TemplateName TName = SubstDefaultTemplateArgument(*this, Template,
3657 return TemplateArgumentLoc();
3659 return TemplateArgumentLoc(TemplateArgument(TName),
3660 TempTempParm->getDefaultArgument().getTemplateQualifierLoc(),
3661 TempTempParm->getDefaultArgument().getTemplateNameLoc());
3664 /// \brief Check that the given template argument corresponds to the given
3665 /// template parameter.
3667 /// \param Param The template parameter against which the argument will be
3670 /// \param Arg The template argument, which may be updated due to conversions.
3672 /// \param Template The template in which the template argument resides.
3674 /// \param TemplateLoc The location of the template name for the template
3675 /// whose argument list we're matching.
3677 /// \param RAngleLoc The location of the right angle bracket ('>') that closes
3678 /// the template argument list.
3680 /// \param ArgumentPackIndex The index into the argument pack where this
3681 /// argument will be placed. Only valid if the parameter is a parameter pack.
3683 /// \param Converted The checked, converted argument will be added to the
3684 /// end of this small vector.
3686 /// \param CTAK Describes how we arrived at this particular template argument:
3687 /// explicitly written, deduced, etc.
3689 /// \returns true on error, false otherwise.
3690 bool Sema::CheckTemplateArgument(NamedDecl *Param,
3691 TemplateArgumentLoc &Arg,
3692 NamedDecl *Template,
3693 SourceLocation TemplateLoc,
3694 SourceLocation RAngleLoc,
3695 unsigned ArgumentPackIndex,
3696 SmallVectorImpl<TemplateArgument> &Converted,
3697 CheckTemplateArgumentKind CTAK) {
3698 // Check template type parameters.
3699 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param))
3700 return CheckTemplateTypeArgument(TTP, Arg, Converted);
3702 // Check non-type template parameters.
3703 if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3704 // Do substitution on the type of the non-type template parameter
3705 // with the template arguments we've seen thus far. But if the
3706 // template has a dependent context then we cannot substitute yet.
3707 QualType NTTPType = NTTP->getType();
3708 if (NTTP->isParameterPack() && NTTP->isExpandedParameterPack())
3709 NTTPType = NTTP->getExpansionType(ArgumentPackIndex);
3711 if (NTTPType->isDependentType() &&
3712 !isa<TemplateTemplateParmDecl>(Template) &&
3713 !Template->getDeclContext()->isDependentContext()) {
3714 // Do substitution on the type of the non-type template parameter.
3715 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
3717 SourceRange(TemplateLoc, RAngleLoc));
3718 if (Inst.isInvalid())
3721 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
3723 NTTPType = SubstType(NTTPType,
3724 MultiLevelTemplateArgumentList(TemplateArgs),
3725 NTTP->getLocation(),
3726 NTTP->getDeclName());
3727 // If that worked, check the non-type template parameter type
3729 if (!NTTPType.isNull())
3730 NTTPType = CheckNonTypeTemplateParameterType(NTTPType,
3731 NTTP->getLocation());
3732 if (NTTPType.isNull())
3736 switch (Arg.getArgument().getKind()) {
3737 case TemplateArgument::Null:
3738 llvm_unreachable("Should never see a NULL template argument here");
3740 case TemplateArgument::Expression: {
3741 TemplateArgument Result;
3743 CheckTemplateArgument(NTTP, NTTPType, Arg.getArgument().getAsExpr(),
3745 if (Res.isInvalid())
3748 // If the resulting expression is new, then use it in place of the
3749 // old expression in the template argument.
3750 if (Res.get() != Arg.getArgument().getAsExpr()) {
3751 TemplateArgument TA(Res.get());
3752 Arg = TemplateArgumentLoc(TA, Res.get());
3755 Converted.push_back(Result);
3759 case TemplateArgument::Declaration:
3760 case TemplateArgument::Integral:
3761 case TemplateArgument::NullPtr:
3762 // We've already checked this template argument, so just copy
3763 // it to the list of converted arguments.
3764 Converted.push_back(Arg.getArgument());
3767 case TemplateArgument::Template:
3768 case TemplateArgument::TemplateExpansion:
3769 // We were given a template template argument. It may not be ill-formed;
3771 if (DependentTemplateName *DTN
3772 = Arg.getArgument().getAsTemplateOrTemplatePattern()
3773 .getAsDependentTemplateName()) {
3774 // We have a template argument such as \c T::template X, which we
3775 // parsed as a template template argument. However, since we now
3776 // know that we need a non-type template argument, convert this
3777 // template name into an expression.
3779 DeclarationNameInfo NameInfo(DTN->getIdentifier(),
3780 Arg.getTemplateNameLoc());
3783 SS.Adopt(Arg.getTemplateQualifierLoc());
3784 // FIXME: the template-template arg was a DependentTemplateName,
3785 // so it was provided with a template keyword. However, its source
3786 // location is not stored in the template argument structure.
3787 SourceLocation TemplateKWLoc;
3788 ExprResult E = DependentScopeDeclRefExpr::Create(
3789 Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo,
3792 // If we parsed the template argument as a pack expansion, create a
3793 // pack expansion expression.
3794 if (Arg.getArgument().getKind() == TemplateArgument::TemplateExpansion){
3795 E = ActOnPackExpansion(E.get(), Arg.getTemplateEllipsisLoc());
3800 TemplateArgument Result;
3801 E = CheckTemplateArgument(NTTP, NTTPType, E.get(), Result);
3805 Converted.push_back(Result);
3809 // We have a template argument that actually does refer to a class
3810 // template, alias template, or template template parameter, and
3811 // therefore cannot be a non-type template argument.
3812 Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr)
3813 << Arg.getSourceRange();
3815 Diag(Param->getLocation(), diag::note_template_param_here);
3818 case TemplateArgument::Type: {
3819 // We have a non-type template parameter but the template
3820 // argument is a type.
3822 // C++ [temp.arg]p2:
3823 // In a template-argument, an ambiguity between a type-id and
3824 // an expression is resolved to a type-id, regardless of the
3825 // form of the corresponding template-parameter.
3827 // We warn specifically about this case, since it can be rather
3828 // confusing for users.
3829 QualType T = Arg.getArgument().getAsType();
3830 SourceRange SR = Arg.getSourceRange();
3831 if (T->isFunctionType())
3832 Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T;
3834 Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR;
3835 Diag(Param->getLocation(), diag::note_template_param_here);
3839 case TemplateArgument::Pack:
3840 llvm_unreachable("Caller must expand template argument packs");
3847 // Check template template parameters.
3848 TemplateTemplateParmDecl *TempParm = cast<TemplateTemplateParmDecl>(Param);
3850 // Substitute into the template parameter list of the template
3851 // template parameter, since previously-supplied template arguments
3852 // may appear within the template template parameter.
3854 // Set up a template instantiation context.
3855 LocalInstantiationScope Scope(*this);
3856 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
3857 TempParm, Converted,
3858 SourceRange(TemplateLoc, RAngleLoc));
3859 if (Inst.isInvalid())
3862 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
3863 TempParm = cast_or_null<TemplateTemplateParmDecl>(
3864 SubstDecl(TempParm, CurContext,
3865 MultiLevelTemplateArgumentList(TemplateArgs)));
3870 switch (Arg.getArgument().getKind()) {
3871 case TemplateArgument::Null:
3872 llvm_unreachable("Should never see a NULL template argument here");
3874 case TemplateArgument::Template:
3875 case TemplateArgument::TemplateExpansion:
3876 if (CheckTemplateArgument(TempParm, Arg, ArgumentPackIndex))
3879 Converted.push_back(Arg.getArgument());
3882 case TemplateArgument::Expression:
3883 case TemplateArgument::Type:
3884 // We have a template template parameter but the template
3885 // argument does not refer to a template.
3886 Diag(Arg.getLocation(), diag::err_template_arg_must_be_template)
3887 << getLangOpts().CPlusPlus11;
3890 case TemplateArgument::Declaration:
3891 llvm_unreachable("Declaration argument with template template parameter");
3892 case TemplateArgument::Integral:
3893 llvm_unreachable("Integral argument with template template parameter");
3894 case TemplateArgument::NullPtr:
3895 llvm_unreachable("Null pointer argument with template template parameter");
3897 case TemplateArgument::Pack:
3898 llvm_unreachable("Caller must expand template argument packs");
3904 /// \brief Diagnose an arity mismatch in the
3905 static bool diagnoseArityMismatch(Sema &S, TemplateDecl *Template,
3906 SourceLocation TemplateLoc,
3907 TemplateArgumentListInfo &TemplateArgs) {
3908 TemplateParameterList *Params = Template->getTemplateParameters();
3909 unsigned NumParams = Params->size();
3910 unsigned NumArgs = TemplateArgs.size();
3913 if (NumArgs > NumParams)
3914 Range = SourceRange(TemplateArgs[NumParams].getLocation(),
3915 TemplateArgs.getRAngleLoc());
3916 S.Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
3917 << (NumArgs > NumParams)
3918 << (isa<ClassTemplateDecl>(Template)? 0 :
3919 isa<FunctionTemplateDecl>(Template)? 1 :
3920 isa<TemplateTemplateParmDecl>(Template)? 2 : 3)
3921 << Template << Range;
3922 S.Diag(Template->getLocation(), diag::note_template_decl_here)
3923 << Params->getSourceRange();
3927 /// \brief Check whether the template parameter is a pack expansion, and if so,
3928 /// determine the number of parameters produced by that expansion. For instance:
3931 /// template<typename ...Ts> struct A {
3932 /// template<Ts ...NTs, template<Ts> class ...TTs, typename ...Us> struct B;
3936 /// In \c A<int,int>::B, \c NTs and \c TTs have expanded pack size 2, and \c Us
3937 /// is not a pack expansion, so returns an empty Optional.
3938 static Optional<unsigned> getExpandedPackSize(NamedDecl *Param) {
3939 if (NonTypeTemplateParmDecl *NTTP
3940 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3941 if (NTTP->isExpandedParameterPack())
3942 return NTTP->getNumExpansionTypes();
3945 if (TemplateTemplateParmDecl *TTP
3946 = dyn_cast<TemplateTemplateParmDecl>(Param)) {
3947 if (TTP->isExpandedParameterPack())
3948 return TTP->getNumExpansionTemplateParameters();
3954 /// Diagnose a missing template argument.
3955 template<typename TemplateParmDecl>
3956 static bool diagnoseMissingArgument(Sema &S, SourceLocation Loc,
3958 const TemplateParmDecl *D,
3959 TemplateArgumentListInfo &Args) {
3960 // Dig out the most recent declaration of the template parameter; there may be
3961 // declarations of the template that are more recent than TD.
3962 D = cast<TemplateParmDecl>(cast<TemplateDecl>(TD->getMostRecentDecl())
3963 ->getTemplateParameters()
3964 ->getParam(D->getIndex()));
3966 // If there's a default argument that's not visible, diagnose that we're
3967 // missing a module import.
3968 llvm::SmallVector<Module*, 8> Modules;
3969 if (D->hasDefaultArgument() && !S.hasVisibleDefaultArgument(D, &Modules)) {
3970 S.diagnoseMissingImport(Loc, cast<NamedDecl>(TD),
3971 D->getDefaultArgumentLoc(), Modules,
3972 Sema::MissingImportKind::DefaultArgument,
3977 // FIXME: If there's a more recent default argument that *is* visible,
3978 // diagnose that it was declared too late.
3980 return diagnoseArityMismatch(S, TD, Loc, Args);
3983 /// \brief Check that the given template argument list is well-formed
3984 /// for specializing the given template.
3985 bool Sema::CheckTemplateArgumentList(TemplateDecl *Template,
3986 SourceLocation TemplateLoc,
3987 TemplateArgumentListInfo &TemplateArgs,
3988 bool PartialTemplateArgs,
3989 SmallVectorImpl<TemplateArgument> &Converted) {
3990 // Make a copy of the template arguments for processing. Only make the
3991 // changes at the end when successful in matching the arguments to the
3993 TemplateArgumentListInfo NewArgs = TemplateArgs;
3995 TemplateParameterList *Params = Template->getTemplateParameters();
3997 SourceLocation RAngleLoc = NewArgs.getRAngleLoc();
3999 // C++ [temp.arg]p1:
4000 // [...] The type and form of each template-argument specified in
4001 // a template-id shall match the type and form specified for the
4002 // corresponding parameter declared by the template in its
4003 // template-parameter-list.
4004 bool isTemplateTemplateParameter = isa<TemplateTemplateParmDecl>(Template);
4005 SmallVector<TemplateArgument, 2> ArgumentPack;
4006 unsigned ArgIdx = 0, NumArgs = NewArgs.size();
4007 LocalInstantiationScope InstScope(*this, true);
4008 for (TemplateParameterList::iterator Param = Params->begin(),
4009 ParamEnd = Params->end();
4010 Param != ParamEnd; /* increment in loop */) {
4011 // If we have an expanded parameter pack, make sure we don't have too
4013 if (Optional<unsigned> Expansions = getExpandedPackSize(*Param)) {
4014 if (*Expansions == ArgumentPack.size()) {
4015 // We're done with this parameter pack. Pack up its arguments and add
4016 // them to the list.
4017 Converted.push_back(
4018 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
4019 ArgumentPack.clear();
4021 // This argument is assigned to the next parameter.
4024 } else if (ArgIdx == NumArgs && !PartialTemplateArgs) {
4025 // Not enough arguments for this parameter pack.
4026 Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
4028 << (isa<ClassTemplateDecl>(Template)? 0 :
4029 isa<FunctionTemplateDecl>(Template)? 1 :
4030 isa<TemplateTemplateParmDecl>(Template)? 2 : 3)
4032 Diag(Template->getLocation(), diag::note_template_decl_here)
4033 << Params->getSourceRange();
4038 if (ArgIdx < NumArgs) {
4039 // Check the template argument we were given.
4040 if (CheckTemplateArgument(*Param, NewArgs[ArgIdx], Template,
4041 TemplateLoc, RAngleLoc,
4042 ArgumentPack.size(), Converted))
4045 bool PackExpansionIntoNonPack =
4046 NewArgs[ArgIdx].getArgument().isPackExpansion() &&
4047 (!(*Param)->isTemplateParameterPack() || getExpandedPackSize(*Param));
4048 if (PackExpansionIntoNonPack && isa<TypeAliasTemplateDecl>(Template)) {
4049 // Core issue 1430: we have a pack expansion as an argument to an
4050 // alias template, and it's not part of a parameter pack. This
4051 // can't be canonicalized, so reject it now.
4052 Diag(NewArgs[ArgIdx].getLocation(),
4053 diag::err_alias_template_expansion_into_fixed_list)
4054 << NewArgs[ArgIdx].getSourceRange();
4055 Diag((*Param)->getLocation(), diag::note_template_param_here);
4059 // We're now done with this argument.
4062 if ((*Param)->isTemplateParameterPack()) {
4063 // The template parameter was a template parameter pack, so take the
4064 // deduced argument and place it on the argument pack. Note that we
4065 // stay on the same template parameter so that we can deduce more
4067 ArgumentPack.push_back(Converted.pop_back_val());
4069 // Move to the next template parameter.
4073 // If we just saw a pack expansion into a non-pack, then directly convert
4074 // the remaining arguments, because we don't know what parameters they'll
4076 if (PackExpansionIntoNonPack) {
4077 if (!ArgumentPack.empty()) {
4078 // If we were part way through filling in an expanded parameter pack,
4079 // fall back to just producing individual arguments.
4080 Converted.insert(Converted.end(),
4081 ArgumentPack.begin(), ArgumentPack.end());
4082 ArgumentPack.clear();
4085 while (ArgIdx < NumArgs) {
4086 Converted.push_back(NewArgs[ArgIdx].getArgument());
4096 // If we're checking a partial template argument list, we're done.
4097 if (PartialTemplateArgs) {
4098 if ((*Param)->isTemplateParameterPack() && !ArgumentPack.empty())
4099 Converted.push_back(
4100 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
4105 // If we have a template parameter pack with no more corresponding
4106 // arguments, just break out now and we'll fill in the argument pack below.
4107 if ((*Param)->isTemplateParameterPack()) {
4108 assert(!getExpandedPackSize(*Param) &&
4109 "Should have dealt with this already");
4111 // A non-expanded parameter pack before the end of the parameter list
4112 // only occurs for an ill-formed template parameter list, unless we've
4113 // got a partial argument list for a function template, so just bail out.
4114 if (Param + 1 != ParamEnd)
4117 Converted.push_back(
4118 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
4119 ArgumentPack.clear();
4125 // Check whether we have a default argument.
4126 TemplateArgumentLoc Arg;
4128 // Retrieve the default template argument from the template
4129 // parameter. For each kind of template parameter, we substitute the
4130 // template arguments provided thus far and any "outer" template arguments
4131 // (when the template parameter was part of a nested template) into
4132 // the default argument.
4133 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*Param)) {
4134 if (!hasVisibleDefaultArgument(TTP))
4135 return diagnoseMissingArgument(*this, TemplateLoc, Template, TTP,
4138 TypeSourceInfo *ArgType = SubstDefaultTemplateArgument(*this,
4147 Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()),
4149 } else if (NonTypeTemplateParmDecl *NTTP
4150 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) {
4151 if (!hasVisibleDefaultArgument(NTTP))
4152 return diagnoseMissingArgument(*this, TemplateLoc, Template, NTTP,
4155 ExprResult E = SubstDefaultTemplateArgument(*this, Template,
4163 Expr *Ex = E.getAs<Expr>();
4164 Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex);
4166 TemplateTemplateParmDecl *TempParm
4167 = cast<TemplateTemplateParmDecl>(*Param);
4169 if (!hasVisibleDefaultArgument(TempParm))
4170 return diagnoseMissingArgument(*this, TemplateLoc, Template, TempParm,
4173 NestedNameSpecifierLoc QualifierLoc;
4174 TemplateName Name = SubstDefaultTemplateArgument(*this, Template,
4183 Arg = TemplateArgumentLoc(TemplateArgument(Name), QualifierLoc,
4184 TempParm->getDefaultArgument().getTemplateNameLoc());
4187 // Introduce an instantiation record that describes where we are using
4188 // the default template argument. We're not actually instantiating a
4189 // template here, we just create this object to put a note into the
4191 InstantiatingTemplate Inst(*this, RAngleLoc, Template, *Param, Converted,
4192 SourceRange(TemplateLoc, RAngleLoc));
4193 if (Inst.isInvalid())
4196 // Check the default template argument.
4197 if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc,
4198 RAngleLoc, 0, Converted))
4201 // Core issue 150 (assumed resolution): if this is a template template
4202 // parameter, keep track of the default template arguments from the
4203 // template definition.
4204 if (isTemplateTemplateParameter)
4205 NewArgs.addArgument(Arg);
4207 // Move to the next template parameter and argument.
4212 // If we're performing a partial argument substitution, allow any trailing
4213 // pack expansions; they might be empty. This can happen even if
4214 // PartialTemplateArgs is false (the list of arguments is complete but
4215 // still dependent).
4216 if (ArgIdx < NumArgs && CurrentInstantiationScope &&
4217 CurrentInstantiationScope->getPartiallySubstitutedPack()) {
4218 while (ArgIdx < NumArgs && NewArgs[ArgIdx].getArgument().isPackExpansion())
4219 Converted.push_back(NewArgs[ArgIdx++].getArgument());
4222 // If we have any leftover arguments, then there were too many arguments.
4223 // Complain and fail.
4224 if (ArgIdx < NumArgs)
4225 return diagnoseArityMismatch(*this, Template, TemplateLoc, NewArgs);
4227 // No problems found with the new argument list, propagate changes back
4229 TemplateArgs = std::move(NewArgs);
4235 class UnnamedLocalNoLinkageFinder
4236 : public TypeVisitor<UnnamedLocalNoLinkageFinder, bool>
4241 typedef TypeVisitor<UnnamedLocalNoLinkageFinder, bool> inherited;
4244 UnnamedLocalNoLinkageFinder(Sema &S, SourceRange SR) : S(S), SR(SR) { }
4246 bool Visit(QualType T) {
4247 return T.isNull() ? false : inherited::Visit(T.getTypePtr());
4250 #define TYPE(Class, Parent) \
4251 bool Visit##Class##Type(const Class##Type *);
4252 #define ABSTRACT_TYPE(Class, Parent) \
4253 bool Visit##Class##Type(const Class##Type *) { return false; }
4254 #define NON_CANONICAL_TYPE(Class, Parent) \
4255 bool Visit##Class##Type(const Class##Type *) { return false; }
4256 #include "clang/AST/TypeNodes.def"
4258 bool VisitTagDecl(const TagDecl *Tag);
4259 bool VisitNestedNameSpecifier(NestedNameSpecifier *NNS);
4261 } // end anonymous namespace
4263 bool UnnamedLocalNoLinkageFinder::VisitBuiltinType(const BuiltinType*) {
4267 bool UnnamedLocalNoLinkageFinder::VisitComplexType(const ComplexType* T) {
4268 return Visit(T->getElementType());
4271 bool UnnamedLocalNoLinkageFinder::VisitPointerType(const PointerType* T) {
4272 return Visit(T->getPointeeType());
4275 bool UnnamedLocalNoLinkageFinder::VisitBlockPointerType(
4276 const BlockPointerType* T) {
4277 return Visit(T->getPointeeType());
4280 bool UnnamedLocalNoLinkageFinder::VisitLValueReferenceType(
4281 const LValueReferenceType* T) {
4282 return Visit(T->getPointeeType());
4285 bool UnnamedLocalNoLinkageFinder::VisitRValueReferenceType(
4286 const RValueReferenceType* T) {
4287 return Visit(T->getPointeeType());
4290 bool UnnamedLocalNoLinkageFinder::VisitMemberPointerType(
4291 const MemberPointerType* T) {
4292 return Visit(T->getPointeeType()) || Visit(QualType(T->getClass(), 0));
4295 bool UnnamedLocalNoLinkageFinder::VisitConstantArrayType(
4296 const ConstantArrayType* T) {
4297 return Visit(T->getElementType());
4300 bool UnnamedLocalNoLinkageFinder::VisitIncompleteArrayType(
4301 const IncompleteArrayType* T) {
4302 return Visit(T->getElementType());
4305 bool UnnamedLocalNoLinkageFinder::VisitVariableArrayType(
4306 const VariableArrayType* T) {
4307 return Visit(T->getElementType());
4310 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedArrayType(
4311 const DependentSizedArrayType* T) {
4312 return Visit(T->getElementType());
4315 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedExtVectorType(
4316 const DependentSizedExtVectorType* T) {
4317 return Visit(T->getElementType());
4320 bool UnnamedLocalNoLinkageFinder::VisitVectorType(const VectorType* T) {
4321 return Visit(T->getElementType());
4324 bool UnnamedLocalNoLinkageFinder::VisitExtVectorType(const ExtVectorType* T) {
4325 return Visit(T->getElementType());
4328 bool UnnamedLocalNoLinkageFinder::VisitFunctionProtoType(
4329 const FunctionProtoType* T) {
4330 for (const auto &A : T->param_types()) {
4335 return Visit(T->getReturnType());
4338 bool UnnamedLocalNoLinkageFinder::VisitFunctionNoProtoType(
4339 const FunctionNoProtoType* T) {
4340 return Visit(T->getReturnType());
4343 bool UnnamedLocalNoLinkageFinder::VisitUnresolvedUsingType(
4344 const UnresolvedUsingType*) {
4348 bool UnnamedLocalNoLinkageFinder::VisitTypeOfExprType(const TypeOfExprType*) {
4352 bool UnnamedLocalNoLinkageFinder::VisitTypeOfType(const TypeOfType* T) {
4353 return Visit(T->getUnderlyingType());
4356 bool UnnamedLocalNoLinkageFinder::VisitDecltypeType(const DecltypeType*) {
4360 bool UnnamedLocalNoLinkageFinder::VisitUnaryTransformType(
4361 const UnaryTransformType*) {
4365 bool UnnamedLocalNoLinkageFinder::VisitAutoType(const AutoType *T) {
4366 return Visit(T->getDeducedType());
4369 bool UnnamedLocalNoLinkageFinder::VisitRecordType(const RecordType* T) {
4370 return VisitTagDecl(T->getDecl());
4373 bool UnnamedLocalNoLinkageFinder::VisitEnumType(const EnumType* T) {
4374 return VisitTagDecl(T->getDecl());
4377 bool UnnamedLocalNoLinkageFinder::VisitTemplateTypeParmType(
4378 const TemplateTypeParmType*) {
4382 bool UnnamedLocalNoLinkageFinder::VisitSubstTemplateTypeParmPackType(
4383 const SubstTemplateTypeParmPackType *) {
4387 bool UnnamedLocalNoLinkageFinder::VisitTemplateSpecializationType(
4388 const TemplateSpecializationType*) {
4392 bool UnnamedLocalNoLinkageFinder::VisitInjectedClassNameType(
4393 const InjectedClassNameType* T) {
4394 return VisitTagDecl(T->getDecl());
4397 bool UnnamedLocalNoLinkageFinder::VisitDependentNameType(
4398 const DependentNameType* T) {
4399 return VisitNestedNameSpecifier(T->getQualifier());
4402 bool UnnamedLocalNoLinkageFinder::VisitDependentTemplateSpecializationType(
4403 const DependentTemplateSpecializationType* T) {
4404 return VisitNestedNameSpecifier(T->getQualifier());
4407 bool UnnamedLocalNoLinkageFinder::VisitPackExpansionType(
4408 const PackExpansionType* T) {
4409 return Visit(T->getPattern());
4412 bool UnnamedLocalNoLinkageFinder::VisitObjCObjectType(const ObjCObjectType *) {
4416 bool UnnamedLocalNoLinkageFinder::VisitObjCInterfaceType(
4417 const ObjCInterfaceType *) {
4421 bool UnnamedLocalNoLinkageFinder::VisitObjCObjectPointerType(
4422 const ObjCObjectPointerType *) {
4426 bool UnnamedLocalNoLinkageFinder::VisitAtomicType(const AtomicType* T) {
4427 return Visit(T->getValueType());
4430 bool UnnamedLocalNoLinkageFinder::VisitPipeType(const PipeType* T) {
4434 bool UnnamedLocalNoLinkageFinder::VisitTagDecl(const TagDecl *Tag) {
4435 if (Tag->getDeclContext()->isFunctionOrMethod()) {
4436 S.Diag(SR.getBegin(),
4437 S.getLangOpts().CPlusPlus11 ?
4438 diag::warn_cxx98_compat_template_arg_local_type :
4439 diag::ext_template_arg_local_type)
4440 << S.Context.getTypeDeclType(Tag) << SR;
4444 if (!Tag->hasNameForLinkage()) {
4445 S.Diag(SR.getBegin(),
4446 S.getLangOpts().CPlusPlus11 ?
4447 diag::warn_cxx98_compat_template_arg_unnamed_type :
4448 diag::ext_template_arg_unnamed_type) << SR;
4449 S.Diag(Tag->getLocation(), diag::note_template_unnamed_type_here);
4456 bool UnnamedLocalNoLinkageFinder::VisitNestedNameSpecifier(
4457 NestedNameSpecifier *NNS) {
4458 if (NNS->getPrefix() && VisitNestedNameSpecifier(NNS->getPrefix()))
4461 switch (NNS->getKind()) {
4462 case NestedNameSpecifier::Identifier:
4463 case NestedNameSpecifier::Namespace:
4464 case NestedNameSpecifier::NamespaceAlias:
4465 case NestedNameSpecifier::Global:
4466 case NestedNameSpecifier::Super:
4469 case NestedNameSpecifier::TypeSpec:
4470 case NestedNameSpecifier::TypeSpecWithTemplate:
4471 return Visit(QualType(NNS->getAsType(), 0));
4473 llvm_unreachable("Invalid NestedNameSpecifier::Kind!");
4476 /// \brief Check a template argument against its corresponding
4477 /// template type parameter.
4479 /// This routine implements the semantics of C++ [temp.arg.type]. It
4480 /// returns true if an error occurred, and false otherwise.
4481 bool Sema::CheckTemplateArgument(TemplateTypeParmDecl *Param,
4482 TypeSourceInfo *ArgInfo) {
4483 assert(ArgInfo && "invalid TypeSourceInfo");
4484 QualType Arg = ArgInfo->getType();
4485 SourceRange SR = ArgInfo->getTypeLoc().getSourceRange();
4487 if (Arg->isVariablyModifiedType()) {
4488 return Diag(SR.getBegin(), diag::err_variably_modified_template_arg) << Arg;
4489 } else if (Context.hasSameUnqualifiedType(Arg, Context.OverloadTy)) {
4490 return Diag(SR.getBegin(), diag::err_template_arg_overload_type) << SR;
4493 // C++03 [temp.arg.type]p2:
4494 // A local type, a type with no linkage, an unnamed type or a type
4495 // compounded from any of these types shall not be used as a
4496 // template-argument for a template type-parameter.
4498 // C++11 allows these, and even in C++03 we allow them as an extension with
4500 if (LangOpts.CPlusPlus11 || Arg->hasUnnamedOrLocalType()) {
4501 UnnamedLocalNoLinkageFinder Finder(*this, SR);
4502 (void)Finder.Visit(Context.getCanonicalType(Arg));
4508 enum NullPointerValueKind {
4514 /// \brief Determine whether the given template argument is a null pointer
4515 /// value of the appropriate type.
4516 static NullPointerValueKind
4517 isNullPointerValueTemplateArgument(Sema &S, NonTypeTemplateParmDecl *Param,
4518 QualType ParamType, Expr *Arg) {
4519 if (Arg->isValueDependent() || Arg->isTypeDependent())
4520 return NPV_NotNullPointer;
4522 if (!S.isCompleteType(Arg->getExprLoc(), ParamType))
4524 "Incomplete parameter type in isNullPointerValueTemplateArgument!");
4526 if (!S.getLangOpts().CPlusPlus11)
4527 return NPV_NotNullPointer;
4529 // Determine whether we have a constant expression.
4530 ExprResult ArgRV = S.DefaultFunctionArrayConversion(Arg);
4531 if (ArgRV.isInvalid())
4535 Expr::EvalResult EvalResult;
4536 SmallVector<PartialDiagnosticAt, 8> Notes;
4537 EvalResult.Diag = &Notes;
4538 if (!Arg->EvaluateAsRValue(EvalResult, S.Context) ||
4539 EvalResult.HasSideEffects) {
4540 SourceLocation DiagLoc = Arg->getExprLoc();
4542 // If our only note is the usual "invalid subexpression" note, just point
4543 // the caret at its location rather than producing an essentially
4545 if (Notes.size() == 1 && Notes[0].second.getDiagID() ==
4546 diag::note_invalid_subexpr_in_const_expr) {
4547 DiagLoc = Notes[0].first;
4551 S.Diag(DiagLoc, diag::err_template_arg_not_address_constant)
4552 << Arg->getType() << Arg->getSourceRange();
4553 for (unsigned I = 0, N = Notes.size(); I != N; ++I)
4554 S.Diag(Notes[I].first, Notes[I].second);
4556 S.Diag(Param->getLocation(), diag::note_template_param_here);
4560 // C++11 [temp.arg.nontype]p1:
4561 // - an address constant expression of type std::nullptr_t
4562 if (Arg->getType()->isNullPtrType())
4563 return NPV_NullPointer;
4565 // - a constant expression that evaluates to a null pointer value (4.10); or
4566 // - a constant expression that evaluates to a null member pointer value
4568 if ((EvalResult.Val.isLValue() && !EvalResult.Val.getLValueBase()) ||
4569 (EvalResult.Val.isMemberPointer() &&
4570 !EvalResult.Val.getMemberPointerDecl())) {
4571 // If our expression has an appropriate type, we've succeeded.
4572 bool ObjCLifetimeConversion;
4573 if (S.Context.hasSameUnqualifiedType(Arg->getType(), ParamType) ||
4574 S.IsQualificationConversion(Arg->getType(), ParamType, false,
4575 ObjCLifetimeConversion))
4576 return NPV_NullPointer;
4578 // The types didn't match, but we know we got a null pointer; complain,
4579 // then recover as if the types were correct.
4580 S.Diag(Arg->getExprLoc(), diag::err_template_arg_wrongtype_null_constant)
4581 << Arg->getType() << ParamType << Arg->getSourceRange();
4582 S.Diag(Param->getLocation(), diag::note_template_param_here);
4583 return NPV_NullPointer;
4586 // If we don't have a null pointer value, but we do have a NULL pointer
4587 // constant, suggest a cast to the appropriate type.
4588 if (Arg->isNullPointerConstant(S.Context, Expr::NPC_NeverValueDependent)) {
4589 std::string Code = "static_cast<" + ParamType.getAsString() + ">(";
4590 S.Diag(Arg->getExprLoc(), diag::err_template_arg_untyped_null_constant)
4591 << ParamType << FixItHint::CreateInsertion(Arg->getLocStart(), Code)
4592 << FixItHint::CreateInsertion(S.getLocForEndOfToken(Arg->getLocEnd()),
4594 S.Diag(Param->getLocation(), diag::note_template_param_here);
4595 return NPV_NullPointer;
4598 // FIXME: If we ever want to support general, address-constant expressions
4599 // as non-type template arguments, we should return the ExprResult here to
4600 // be interpreted by the caller.
4601 return NPV_NotNullPointer;
4604 /// \brief Checks whether the given template argument is compatible with its
4605 /// template parameter.
4606 static bool CheckTemplateArgumentIsCompatibleWithParameter(
4607 Sema &S, NonTypeTemplateParmDecl *Param, QualType ParamType, Expr *ArgIn,
4608 Expr *Arg, QualType ArgType) {
4609 bool ObjCLifetimeConversion;
4610 if (ParamType->isPointerType() &&
4611 !ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType() &&
4612 S.IsQualificationConversion(ArgType, ParamType, false,
4613 ObjCLifetimeConversion)) {
4614 // For pointer-to-object types, qualification conversions are
4617 if (const ReferenceType *ParamRef = ParamType->getAs<ReferenceType>()) {
4618 if (!ParamRef->getPointeeType()->isFunctionType()) {
4619 // C++ [temp.arg.nontype]p5b3:
4620 // For a non-type template-parameter of type reference to
4621 // object, no conversions apply. The type referred to by the
4622 // reference may be more cv-qualified than the (otherwise
4623 // identical) type of the template- argument. The
4624 // template-parameter is bound directly to the
4625 // template-argument, which shall be an lvalue.
4627 // FIXME: Other qualifiers?
4628 unsigned ParamQuals = ParamRef->getPointeeType().getCVRQualifiers();
4629 unsigned ArgQuals = ArgType.getCVRQualifiers();
4631 if ((ParamQuals | ArgQuals) != ParamQuals) {
4632 S.Diag(Arg->getLocStart(),
4633 diag::err_template_arg_ref_bind_ignores_quals)
4634 << ParamType << Arg->getType() << Arg->getSourceRange();
4635 S.Diag(Param->getLocation(), diag::note_template_param_here);
4641 // At this point, the template argument refers to an object or
4642 // function with external linkage. We now need to check whether the
4643 // argument and parameter types are compatible.
4644 if (!S.Context.hasSameUnqualifiedType(ArgType,
4645 ParamType.getNonReferenceType())) {
4646 // We can't perform this conversion or binding.
4647 if (ParamType->isReferenceType())
4648 S.Diag(Arg->getLocStart(), diag::err_template_arg_no_ref_bind)
4649 << ParamType << ArgIn->getType() << Arg->getSourceRange();
4651 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible)
4652 << ArgIn->getType() << ParamType << Arg->getSourceRange();
4653 S.Diag(Param->getLocation(), diag::note_template_param_here);
4661 /// \brief Checks whether the given template argument is the address
4662 /// of an object or function according to C++ [temp.arg.nontype]p1.
4664 CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S,
4665 NonTypeTemplateParmDecl *Param,
4668 TemplateArgument &Converted) {
4669 bool Invalid = false;
4671 QualType ArgType = Arg->getType();
4673 bool AddressTaken = false;
4674 SourceLocation AddrOpLoc;
4675 if (S.getLangOpts().MicrosoftExt) {
4676 // Microsoft Visual C++ strips all casts, allows an arbitrary number of
4677 // dereference and address-of operators.
4678 Arg = Arg->IgnoreParenCasts();
4680 bool ExtWarnMSTemplateArg = false;
4681 UnaryOperatorKind FirstOpKind;
4682 SourceLocation FirstOpLoc;
4683 while (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
4684 UnaryOperatorKind UnOpKind = UnOp->getOpcode();
4685 if (UnOpKind == UO_Deref)
4686 ExtWarnMSTemplateArg = true;
4687 if (UnOpKind == UO_AddrOf || UnOpKind == UO_Deref) {
4688 Arg = UnOp->getSubExpr()->IgnoreParenCasts();
4689 if (!AddrOpLoc.isValid()) {
4690 FirstOpKind = UnOpKind;
4691 FirstOpLoc = UnOp->getOperatorLoc();
4696 if (FirstOpLoc.isValid()) {
4697 if (ExtWarnMSTemplateArg)
4698 S.Diag(ArgIn->getLocStart(), diag::ext_ms_deref_template_argument)
4699 << ArgIn->getSourceRange();
4701 if (FirstOpKind == UO_AddrOf)
4702 AddressTaken = true;
4703 else if (Arg->getType()->isPointerType()) {
4704 // We cannot let pointers get dereferenced here, that is obviously not a
4705 // constant expression.
4706 assert(FirstOpKind == UO_Deref);
4707 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
4708 << Arg->getSourceRange();
4712 // See through any implicit casts we added to fix the type.
4713 Arg = Arg->IgnoreImpCasts();
4715 // C++ [temp.arg.nontype]p1:
4717 // A template-argument for a non-type, non-template
4718 // template-parameter shall be one of: [...]
4720 // -- the address of an object or function with external
4721 // linkage, including function templates and function
4722 // template-ids but excluding non-static class members,
4723 // expressed as & id-expression where the & is optional if
4724 // the name refers to a function or array, or if the
4725 // corresponding template-parameter is a reference; or
4727 // In C++98/03 mode, give an extension warning on any extra parentheses.
4728 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
4729 bool ExtraParens = false;
4730 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) {
4731 if (!Invalid && !ExtraParens) {
4732 S.Diag(Arg->getLocStart(),
4733 S.getLangOpts().CPlusPlus11
4734 ? diag::warn_cxx98_compat_template_arg_extra_parens
4735 : diag::ext_template_arg_extra_parens)
4736 << Arg->getSourceRange();
4740 Arg = Parens->getSubExpr();
4743 while (SubstNonTypeTemplateParmExpr *subst =
4744 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
4745 Arg = subst->getReplacement()->IgnoreImpCasts();
4747 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
4748 if (UnOp->getOpcode() == UO_AddrOf) {
4749 Arg = UnOp->getSubExpr();
4750 AddressTaken = true;
4751 AddrOpLoc = UnOp->getOperatorLoc();
4755 while (SubstNonTypeTemplateParmExpr *subst =
4756 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
4757 Arg = subst->getReplacement()->IgnoreImpCasts();
4760 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg);
4761 ValueDecl *Entity = DRE ? DRE->getDecl() : nullptr;
4763 // If our parameter has pointer type, check for a null template value.
4764 if (ParamType->isPointerType() || ParamType->isNullPtrType()) {
4765 NullPointerValueKind NPV;
4766 // dllimport'd entities aren't constant but are available inside of template
4768 if (Entity && Entity->hasAttr<DLLImportAttr>())
4769 NPV = NPV_NotNullPointer;
4771 NPV = isNullPointerValueTemplateArgument(S, Param, ParamType, ArgIn);
4773 case NPV_NullPointer:
4774 S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
4775 Converted = TemplateArgument(S.Context.getCanonicalType(ParamType),
4776 /*isNullPtr=*/true);
4782 case NPV_NotNullPointer:
4787 // Stop checking the precise nature of the argument if it is value dependent,
4788 // it should be checked when instantiated.
4789 if (Arg->isValueDependent()) {
4790 Converted = TemplateArgument(ArgIn);
4794 if (isa<CXXUuidofExpr>(Arg)) {
4795 if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType,
4796 ArgIn, Arg, ArgType))
4799 Converted = TemplateArgument(ArgIn);
4804 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
4805 << Arg->getSourceRange();
4806 S.Diag(Param->getLocation(), diag::note_template_param_here);
4810 // Cannot refer to non-static data members
4811 if (isa<FieldDecl>(Entity) || isa<IndirectFieldDecl>(Entity)) {
4812 S.Diag(Arg->getLocStart(), diag::err_template_arg_field)
4813 << Entity << Arg->getSourceRange();
4814 S.Diag(Param->getLocation(), diag::note_template_param_here);
4818 // Cannot refer to non-static member functions
4819 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Entity)) {
4820 if (!Method->isStatic()) {
4821 S.Diag(Arg->getLocStart(), diag::err_template_arg_method)
4822 << Method << Arg->getSourceRange();
4823 S.Diag(Param->getLocation(), diag::note_template_param_here);
4828 FunctionDecl *Func = dyn_cast<FunctionDecl>(Entity);
4829 VarDecl *Var = dyn_cast<VarDecl>(Entity);
4831 // A non-type template argument must refer to an object or function.
4832 if (!Func && !Var) {
4833 // We found something, but we don't know specifically what it is.
4834 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_object_or_func)
4835 << Arg->getSourceRange();
4836 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here);
4840 // Address / reference template args must have external linkage in C++98.
4841 if (Entity->getFormalLinkage() == InternalLinkage) {
4842 S.Diag(Arg->getLocStart(), S.getLangOpts().CPlusPlus11 ?
4843 diag::warn_cxx98_compat_template_arg_object_internal :
4844 diag::ext_template_arg_object_internal)
4845 << !Func << Entity << Arg->getSourceRange();
4846 S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
4848 } else if (!Entity->hasLinkage()) {
4849 S.Diag(Arg->getLocStart(), diag::err_template_arg_object_no_linkage)
4850 << !Func << Entity << Arg->getSourceRange();
4851 S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
4857 // If the template parameter has pointer type, the function decays.
4858 if (ParamType->isPointerType() && !AddressTaken)
4859 ArgType = S.Context.getPointerType(Func->getType());
4860 else if (AddressTaken && ParamType->isReferenceType()) {
4861 // If we originally had an address-of operator, but the
4862 // parameter has reference type, complain and (if things look
4863 // like they will work) drop the address-of operator.
4864 if (!S.Context.hasSameUnqualifiedType(Func->getType(),
4865 ParamType.getNonReferenceType())) {
4866 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4868 S.Diag(Param->getLocation(), diag::note_template_param_here);
4872 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4874 << FixItHint::CreateRemoval(AddrOpLoc);
4875 S.Diag(Param->getLocation(), diag::note_template_param_here);
4877 ArgType = Func->getType();
4880 // A value of reference type is not an object.
4881 if (Var->getType()->isReferenceType()) {
4882 S.Diag(Arg->getLocStart(),
4883 diag::err_template_arg_reference_var)
4884 << Var->getType() << Arg->getSourceRange();
4885 S.Diag(Param->getLocation(), diag::note_template_param_here);
4889 // A template argument must have static storage duration.
4890 if (Var->getTLSKind()) {
4891 S.Diag(Arg->getLocStart(), diag::err_template_arg_thread_local)
4892 << Arg->getSourceRange();
4893 S.Diag(Var->getLocation(), diag::note_template_arg_refers_here);
4897 // If the template parameter has pointer type, we must have taken
4898 // the address of this object.
4899 if (ParamType->isReferenceType()) {
4901 // If we originally had an address-of operator, but the
4902 // parameter has reference type, complain and (if things look
4903 // like they will work) drop the address-of operator.
4904 if (!S.Context.hasSameUnqualifiedType(Var->getType(),
4905 ParamType.getNonReferenceType())) {
4906 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4908 S.Diag(Param->getLocation(), diag::note_template_param_here);
4912 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4914 << FixItHint::CreateRemoval(AddrOpLoc);
4915 S.Diag(Param->getLocation(), diag::note_template_param_here);
4917 ArgType = Var->getType();
4919 } else if (!AddressTaken && ParamType->isPointerType()) {
4920 if (Var->getType()->isArrayType()) {
4921 // Array-to-pointer decay.
4922 ArgType = S.Context.getArrayDecayedType(Var->getType());
4924 // If the template parameter has pointer type but the address of
4925 // this object was not taken, complain and (possibly) recover by
4926 // taking the address of the entity.
4927 ArgType = S.Context.getPointerType(Var->getType());
4928 if (!S.Context.hasSameUnqualifiedType(ArgType, ParamType)) {
4929 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of)
4931 S.Diag(Param->getLocation(), diag::note_template_param_here);
4935 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of)
4937 << FixItHint::CreateInsertion(Arg->getLocStart(), "&");
4939 S.Diag(Param->getLocation(), diag::note_template_param_here);
4944 if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType, ArgIn,
4948 // Create the template argument.
4950 TemplateArgument(cast<ValueDecl>(Entity->getCanonicalDecl()), ParamType);
4951 S.MarkAnyDeclReferenced(Arg->getLocStart(), Entity, false);
4955 /// \brief Checks whether the given template argument is a pointer to
4956 /// member constant according to C++ [temp.arg.nontype]p1.
4957 static bool CheckTemplateArgumentPointerToMember(Sema &S,
4958 NonTypeTemplateParmDecl *Param,
4961 TemplateArgument &Converted) {
4962 bool Invalid = false;
4964 // Check for a null pointer value.
4965 Expr *Arg = ResultArg;
4966 switch (isNullPointerValueTemplateArgument(S, Param, ParamType, Arg)) {
4969 case NPV_NullPointer:
4970 S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
4971 Converted = TemplateArgument(S.Context.getCanonicalType(ParamType),
4974 case NPV_NotNullPointer:
4978 bool ObjCLifetimeConversion;
4979 if (S.IsQualificationConversion(Arg->getType(),
4980 ParamType.getNonReferenceType(),
4981 false, ObjCLifetimeConversion)) {
4982 Arg = S.ImpCastExprToType(Arg, ParamType, CK_NoOp,
4983 Arg->getValueKind()).get();
4985 } else if (!S.Context.hasSameUnqualifiedType(Arg->getType(),
4986 ParamType.getNonReferenceType())) {
4987 // We can't perform this conversion.
4988 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible)
4989 << Arg->getType() << ParamType << Arg->getSourceRange();
4990 S.Diag(Param->getLocation(), diag::note_template_param_here);
4994 // See through any implicit casts we added to fix the type.
4995 while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg))
4996 Arg = Cast->getSubExpr();
4998 // C++ [temp.arg.nontype]p1:
5000 // A template-argument for a non-type, non-template
5001 // template-parameter shall be one of: [...]
5003 // -- a pointer to member expressed as described in 5.3.1.
5004 DeclRefExpr *DRE = nullptr;
5006 // In C++98/03 mode, give an extension warning on any extra parentheses.
5007 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
5008 bool ExtraParens = false;
5009 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) {
5010 if (!Invalid && !ExtraParens) {
5011 S.Diag(Arg->getLocStart(),
5012 S.getLangOpts().CPlusPlus11 ?
5013 diag::warn_cxx98_compat_template_arg_extra_parens :
5014 diag::ext_template_arg_extra_parens)
5015 << Arg->getSourceRange();
5019 Arg = Parens->getSubExpr();
5022 while (SubstNonTypeTemplateParmExpr *subst =
5023 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
5024 Arg = subst->getReplacement()->IgnoreImpCasts();
5026 // A pointer-to-member constant written &Class::member.
5027 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
5028 if (UnOp->getOpcode() == UO_AddrOf) {
5029 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr());
5030 if (DRE && !DRE->getQualifier())
5034 // A constant of pointer-to-member type.
5035 else if ((DRE = dyn_cast<DeclRefExpr>(Arg))) {
5036 if (ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl())) {
5037 if (VD->getType()->isMemberPointerType()) {
5038 if (isa<NonTypeTemplateParmDecl>(VD)) {
5039 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
5040 Converted = TemplateArgument(Arg);
5042 VD = cast<ValueDecl>(VD->getCanonicalDecl());
5043 Converted = TemplateArgument(VD, ParamType);
5054 return S.Diag(Arg->getLocStart(),
5055 diag::err_template_arg_not_pointer_to_member_form)
5056 << Arg->getSourceRange();
5058 if (isa<FieldDecl>(DRE->getDecl()) ||
5059 isa<IndirectFieldDecl>(DRE->getDecl()) ||
5060 isa<CXXMethodDecl>(DRE->getDecl())) {
5061 assert((isa<FieldDecl>(DRE->getDecl()) ||
5062 isa<IndirectFieldDecl>(DRE->getDecl()) ||
5063 !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) &&
5064 "Only non-static member pointers can make it here");
5066 // Okay: this is the address of a non-static member, and therefore
5067 // a member pointer constant.
5068 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
5069 Converted = TemplateArgument(Arg);
5071 ValueDecl *D = cast<ValueDecl>(DRE->getDecl()->getCanonicalDecl());
5072 Converted = TemplateArgument(D, ParamType);
5077 // We found something else, but we don't know specifically what it is.
5078 S.Diag(Arg->getLocStart(),
5079 diag::err_template_arg_not_pointer_to_member_form)
5080 << Arg->getSourceRange();
5081 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here);
5085 /// \brief Check a template argument against its corresponding
5086 /// non-type template parameter.
5088 /// This routine implements the semantics of C++ [temp.arg.nontype].
5089 /// If an error occurred, it returns ExprError(); otherwise, it
5090 /// returns the converted template argument. \p ParamType is the
5091 /// type of the non-type template parameter after it has been instantiated.
5092 ExprResult Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
5093 QualType ParamType, Expr *Arg,
5094 TemplateArgument &Converted,
5095 CheckTemplateArgumentKind CTAK) {
5096 SourceLocation StartLoc = Arg->getLocStart();
5098 // If the parameter type somehow involves auto, deduce the type now.
5099 if (getLangOpts().CPlusPlus1z && ParamType->isUndeducedType()) {
5100 // When checking a deduced template argument, deduce from its type even if
5101 // the type is dependent, in order to check the types of non-type template
5102 // arguments line up properly in partial ordering.
5103 Optional<unsigned> Depth;
5104 if (CTAK != CTAK_Specified)
5105 Depth = Param->getDepth() + 1;
5107 Context.getTrivialTypeSourceInfo(ParamType, Param->getLocation()),
5108 Arg, ParamType, Depth) == DAR_Failed) {
5109 Diag(Arg->getExprLoc(),
5110 diag::err_non_type_template_parm_type_deduction_failure)
5111 << Param->getDeclName() << Param->getType() << Arg->getType()
5112 << Arg->getSourceRange();
5113 Diag(Param->getLocation(), diag::note_template_param_here);
5116 // CheckNonTypeTemplateParameterType will produce a diagnostic if there's
5117 // an error. The error message normally references the parameter
5118 // declaration, but here we'll pass the argument location because that's
5119 // where the parameter type is deduced.
5120 ParamType = CheckNonTypeTemplateParameterType(ParamType, Arg->getExprLoc());
5121 if (ParamType.isNull()) {
5122 Diag(Param->getLocation(), diag::note_template_param_here);
5127 // We should have already dropped all cv-qualifiers by now.
5128 assert(!ParamType.hasQualifiers() &&
5129 "non-type template parameter type cannot be qualified");
5131 if (CTAK == CTAK_Deduced &&
5132 !Context.hasSameType(ParamType.getNonLValueExprType(Context),
5134 // C++ [temp.deduct.type]p17: (DR1770)
5135 // If P has a form that contains <i>, and if the type of i differs from
5136 // the type of the corresponding template parameter of the template named
5137 // by the enclosing simple-template-id, deduction fails.
5139 // Note that CTAK will be CTAK_DeducedFromArrayBound if the form was [i]
5142 // FIXME: We interpret the 'i' here as referring to the expression
5143 // denoting the non-type template parameter rather than the parameter
5144 // itself, and so strip off references before comparing types. It's
5145 // not clear how this is supposed to work for references.
5146 Diag(StartLoc, diag::err_deduced_non_type_template_arg_type_mismatch)
5148 << ParamType.getUnqualifiedType();
5149 Diag(Param->getLocation(), diag::note_template_param_here);
5153 // If either the parameter has a dependent type or the argument is
5154 // type-dependent, there's nothing we can check now.
5155 if (ParamType->isDependentType() || Arg->isTypeDependent()) {
5156 // FIXME: Produce a cloned, canonical expression?
5157 Converted = TemplateArgument(Arg);
5161 if (getLangOpts().CPlusPlus1z) {
5162 // C++1z [temp.arg.nontype]p1:
5163 // A template-argument for a non-type template parameter shall be
5164 // a converted constant expression of the type of the template-parameter.
5166 ExprResult ArgResult = CheckConvertedConstantExpression(
5167 Arg, ParamType, Value, CCEK_TemplateArg);
5168 if (ArgResult.isInvalid())
5171 // For a value-dependent argument, CheckConvertedConstantExpression is
5172 // permitted (and expected) to be unable to determine a value.
5173 if (ArgResult.get()->isValueDependent()) {
5174 Converted = TemplateArgument(ArgResult.get());
5178 QualType CanonParamType = Context.getCanonicalType(ParamType);
5180 // Convert the APValue to a TemplateArgument.
5181 switch (Value.getKind()) {
5182 case APValue::Uninitialized:
5183 assert(ParamType->isNullPtrType());
5184 Converted = TemplateArgument(CanonParamType, /*isNullPtr*/true);
5187 assert(ParamType->isIntegralOrEnumerationType());
5188 Converted = TemplateArgument(Context, Value.getInt(), CanonParamType);
5190 case APValue::MemberPointer: {
5191 assert(ParamType->isMemberPointerType());
5193 // FIXME: We need TemplateArgument representation and mangling for these.
5194 if (!Value.getMemberPointerPath().empty()) {
5195 Diag(Arg->getLocStart(),
5196 diag::err_template_arg_member_ptr_base_derived_not_supported)
5197 << Value.getMemberPointerDecl() << ParamType
5198 << Arg->getSourceRange();
5202 auto *VD = const_cast<ValueDecl*>(Value.getMemberPointerDecl());
5203 Converted = VD ? TemplateArgument(VD, CanonParamType)
5204 : TemplateArgument(CanonParamType, /*isNullPtr*/true);
5207 case APValue::LValue: {
5208 // For a non-type template-parameter of pointer or reference type,
5209 // the value of the constant expression shall not refer to
5210 assert(ParamType->isPointerType() || ParamType->isReferenceType() ||
5211 ParamType->isNullPtrType());
5212 // -- a temporary object
5213 // -- a string literal
5214 // -- the result of a typeid expression, or
5215 // -- a predefind __func__ variable
5216 if (auto *E = Value.getLValueBase().dyn_cast<const Expr*>()) {
5217 if (isa<CXXUuidofExpr>(E)) {
5218 Converted = TemplateArgument(const_cast<Expr*>(E));
5221 Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
5222 << Arg->getSourceRange();
5225 auto *VD = const_cast<ValueDecl *>(
5226 Value.getLValueBase().dyn_cast<const ValueDecl *>());
5228 if (Value.hasLValuePath() && Value.getLValuePath().size() == 1 &&
5229 VD && VD->getType()->isArrayType() &&
5230 Value.getLValuePath()[0].ArrayIndex == 0 &&
5231 !Value.isLValueOnePastTheEnd() && ParamType->isPointerType()) {
5232 // Per defect report (no number yet):
5233 // ... other than a pointer to the first element of a complete array
5235 } else if (!Value.hasLValuePath() || Value.getLValuePath().size() ||
5236 Value.isLValueOnePastTheEnd()) {
5237 Diag(StartLoc, diag::err_non_type_template_arg_subobject)
5238 << Value.getAsString(Context, ParamType);
5241 assert((VD || !ParamType->isReferenceType()) &&
5242 "null reference should not be a constant expression");
5243 assert((!VD || !ParamType->isNullPtrType()) &&
5244 "non-null value of type nullptr_t?");
5245 Converted = VD ? TemplateArgument(VD, CanonParamType)
5246 : TemplateArgument(CanonParamType, /*isNullPtr*/true);
5249 case APValue::AddrLabelDiff:
5250 return Diag(StartLoc, diag::err_non_type_template_arg_addr_label_diff);
5251 case APValue::Float:
5252 case APValue::ComplexInt:
5253 case APValue::ComplexFloat:
5254 case APValue::Vector:
5255 case APValue::Array:
5256 case APValue::Struct:
5257 case APValue::Union:
5258 llvm_unreachable("invalid kind for template argument");
5261 return ArgResult.get();
5264 // C++ [temp.arg.nontype]p5:
5265 // The following conversions are performed on each expression used
5266 // as a non-type template-argument. If a non-type
5267 // template-argument cannot be converted to the type of the
5268 // corresponding template-parameter then the program is
5270 if (ParamType->isIntegralOrEnumerationType()) {
5272 // -- for a non-type template-parameter of integral or
5273 // enumeration type, conversions permitted in a converted
5274 // constant expression are applied.
5277 // -- for a non-type template-parameter of integral or
5278 // enumeration type, integral promotions (4.5) and integral
5279 // conversions (4.7) are applied.
5281 if (getLangOpts().CPlusPlus11) {
5282 // C++ [temp.arg.nontype]p1:
5283 // A template-argument for a non-type, non-template template-parameter
5286 // -- for a non-type template-parameter of integral or enumeration
5287 // type, a converted constant expression of the type of the
5288 // template-parameter; or
5290 ExprResult ArgResult =
5291 CheckConvertedConstantExpression(Arg, ParamType, Value,
5293 if (ArgResult.isInvalid())
5296 // We can't check arbitrary value-dependent arguments.
5297 if (ArgResult.get()->isValueDependent()) {
5298 Converted = TemplateArgument(ArgResult.get());
5302 // Widen the argument value to sizeof(parameter type). This is almost
5303 // always a no-op, except when the parameter type is bool. In
5304 // that case, this may extend the argument from 1 bit to 8 bits.
5305 QualType IntegerType = ParamType;
5306 if (const EnumType *Enum = IntegerType->getAs<EnumType>())
5307 IntegerType = Enum->getDecl()->getIntegerType();
5308 Value = Value.extOrTrunc(Context.getTypeSize(IntegerType));
5310 Converted = TemplateArgument(Context, Value,
5311 Context.getCanonicalType(ParamType));
5315 ExprResult ArgResult = DefaultLvalueConversion(Arg);
5316 if (ArgResult.isInvalid())
5318 Arg = ArgResult.get();
5320 QualType ArgType = Arg->getType();
5322 // C++ [temp.arg.nontype]p1:
5323 // A template-argument for a non-type, non-template
5324 // template-parameter shall be one of:
5326 // -- an integral constant-expression of integral or enumeration
5328 // -- the name of a non-type template-parameter; or
5329 SourceLocation NonConstantLoc;
5331 if (!ArgType->isIntegralOrEnumerationType()) {
5332 Diag(Arg->getLocStart(),
5333 diag::err_template_arg_not_integral_or_enumeral)
5334 << ArgType << Arg->getSourceRange();
5335 Diag(Param->getLocation(), diag::note_template_param_here);
5337 } else if (!Arg->isValueDependent()) {
5338 class TmplArgICEDiagnoser : public VerifyICEDiagnoser {
5342 TmplArgICEDiagnoser(QualType T) : T(T) { }
5344 void diagnoseNotICE(Sema &S, SourceLocation Loc,
5345 SourceRange SR) override {
5346 S.Diag(Loc, diag::err_template_arg_not_ice) << T << SR;
5348 } Diagnoser(ArgType);
5350 Arg = VerifyIntegerConstantExpression(Arg, &Value, Diagnoser,
5356 // From here on out, all we care about is the unqualified form
5357 // of the argument type.
5358 ArgType = ArgType.getUnqualifiedType();
5360 // Try to convert the argument to the parameter's type.
5361 if (Context.hasSameType(ParamType, ArgType)) {
5362 // Okay: no conversion necessary
5363 } else if (ParamType->isBooleanType()) {
5364 // This is an integral-to-boolean conversion.
5365 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralToBoolean).get();
5366 } else if (IsIntegralPromotion(Arg, ArgType, ParamType) ||
5367 !ParamType->isEnumeralType()) {
5368 // This is an integral promotion or conversion.
5369 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralCast).get();
5371 // We can't perform this conversion.
5372 Diag(Arg->getLocStart(),
5373 diag::err_template_arg_not_convertible)
5374 << Arg->getType() << ParamType << Arg->getSourceRange();
5375 Diag(Param->getLocation(), diag::note_template_param_here);
5379 // Add the value of this argument to the list of converted
5380 // arguments. We use the bitwidth and signedness of the template
5382 if (Arg->isValueDependent()) {
5383 // The argument is value-dependent. Create a new
5384 // TemplateArgument with the converted expression.
5385 Converted = TemplateArgument(Arg);
5389 QualType IntegerType = Context.getCanonicalType(ParamType);
5390 if (const EnumType *Enum = IntegerType->getAs<EnumType>())
5391 IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType());
5393 if (ParamType->isBooleanType()) {
5394 // Value must be zero or one.
5396 unsigned AllowedBits = Context.getTypeSize(IntegerType);
5397 if (Value.getBitWidth() != AllowedBits)
5398 Value = Value.extOrTrunc(AllowedBits);
5399 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
5401 llvm::APSInt OldValue = Value;
5403 // Coerce the template argument's value to the value it will have
5404 // based on the template parameter's type.
5405 unsigned AllowedBits = Context.getTypeSize(IntegerType);
5406 if (Value.getBitWidth() != AllowedBits)
5407 Value = Value.extOrTrunc(AllowedBits);
5408 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
5410 // Complain if an unsigned parameter received a negative value.
5411 if (IntegerType->isUnsignedIntegerOrEnumerationType()
5412 && (OldValue.isSigned() && OldValue.isNegative())) {
5413 Diag(Arg->getLocStart(), diag::warn_template_arg_negative)
5414 << OldValue.toString(10) << Value.toString(10) << Param->getType()
5415 << Arg->getSourceRange();
5416 Diag(Param->getLocation(), diag::note_template_param_here);
5419 // Complain if we overflowed the template parameter's type.
5420 unsigned RequiredBits;
5421 if (IntegerType->isUnsignedIntegerOrEnumerationType())
5422 RequiredBits = OldValue.getActiveBits();
5423 else if (OldValue.isUnsigned())
5424 RequiredBits = OldValue.getActiveBits() + 1;
5426 RequiredBits = OldValue.getMinSignedBits();
5427 if (RequiredBits > AllowedBits) {
5428 Diag(Arg->getLocStart(),
5429 diag::warn_template_arg_too_large)
5430 << OldValue.toString(10) << Value.toString(10) << Param->getType()
5431 << Arg->getSourceRange();
5432 Diag(Param->getLocation(), diag::note_template_param_here);
5436 Converted = TemplateArgument(Context, Value,
5437 ParamType->isEnumeralType()
5438 ? Context.getCanonicalType(ParamType)
5443 QualType ArgType = Arg->getType();
5444 DeclAccessPair FoundResult; // temporary for ResolveOverloadedFunction
5446 // Handle pointer-to-function, reference-to-function, and
5447 // pointer-to-member-function all in (roughly) the same way.
5448 if (// -- For a non-type template-parameter of type pointer to
5449 // function, only the function-to-pointer conversion (4.3) is
5450 // applied. If the template-argument represents a set of
5451 // overloaded functions (or a pointer to such), the matching
5452 // function is selected from the set (13.4).
5453 (ParamType->isPointerType() &&
5454 ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType()) ||
5455 // -- For a non-type template-parameter of type reference to
5456 // function, no conversions apply. If the template-argument
5457 // represents a set of overloaded functions, the matching
5458 // function is selected from the set (13.4).
5459 (ParamType->isReferenceType() &&
5460 ParamType->getAs<ReferenceType>()->getPointeeType()->isFunctionType()) ||
5461 // -- For a non-type template-parameter of type pointer to
5462 // member function, no conversions apply. If the
5463 // template-argument represents a set of overloaded member
5464 // functions, the matching member function is selected from
5466 (ParamType->isMemberPointerType() &&
5467 ParamType->getAs<MemberPointerType>()->getPointeeType()
5468 ->isFunctionType())) {
5470 if (Arg->getType() == Context.OverloadTy) {
5471 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType,
5474 if (DiagnoseUseOfDecl(Fn, Arg->getLocStart()))
5477 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
5478 ArgType = Arg->getType();
5483 if (!ParamType->isMemberPointerType()) {
5484 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5491 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
5497 if (ParamType->isPointerType()) {
5498 // -- for a non-type template-parameter of type pointer to
5499 // object, qualification conversions (4.4) and the
5500 // array-to-pointer conversion (4.2) are applied.
5501 // C++0x also allows a value of std::nullptr_t.
5502 assert(ParamType->getPointeeType()->isIncompleteOrObjectType() &&
5503 "Only object pointers allowed here");
5505 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5512 if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) {
5513 // -- For a non-type template-parameter of type reference to
5514 // object, no conversions apply. The type referred to by the
5515 // reference may be more cv-qualified than the (otherwise
5516 // identical) type of the template-argument. The
5517 // template-parameter is bound directly to the
5518 // template-argument, which must be an lvalue.
5519 assert(ParamRefType->getPointeeType()->isIncompleteOrObjectType() &&
5520 "Only object references allowed here");
5522 if (Arg->getType() == Context.OverloadTy) {
5523 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg,
5524 ParamRefType->getPointeeType(),
5527 if (DiagnoseUseOfDecl(Fn, Arg->getLocStart()))
5530 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
5531 ArgType = Arg->getType();
5536 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5543 // Deal with parameters of type std::nullptr_t.
5544 if (ParamType->isNullPtrType()) {
5545 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
5546 Converted = TemplateArgument(Arg);
5550 switch (isNullPointerValueTemplateArgument(*this, Param, ParamType, Arg)) {
5551 case NPV_NotNullPointer:
5552 Diag(Arg->getExprLoc(), diag::err_template_arg_not_convertible)
5553 << Arg->getType() << ParamType;
5554 Diag(Param->getLocation(), diag::note_template_param_here);
5560 case NPV_NullPointer:
5561 Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
5562 Converted = TemplateArgument(Context.getCanonicalType(ParamType),
5568 // -- For a non-type template-parameter of type pointer to data
5569 // member, qualification conversions (4.4) are applied.
5570 assert(ParamType->isMemberPointerType() && "Only pointers to members remain");
5572 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
5578 static void DiagnoseTemplateParameterListArityMismatch(
5579 Sema &S, TemplateParameterList *New, TemplateParameterList *Old,
5580 Sema::TemplateParameterListEqualKind Kind, SourceLocation TemplateArgLoc);
5582 /// \brief Check a template argument against its corresponding
5583 /// template template parameter.
5585 /// This routine implements the semantics of C++ [temp.arg.template].
5586 /// It returns true if an error occurred, and false otherwise.
5587 bool Sema::CheckTemplateArgument(TemplateTemplateParmDecl *Param,
5588 TemplateArgumentLoc &Arg,
5589 unsigned ArgumentPackIndex) {
5590 TemplateName Name = Arg.getArgument().getAsTemplateOrTemplatePattern();
5591 TemplateDecl *Template = Name.getAsTemplateDecl();
5593 // Any dependent template name is fine.
5594 assert(Name.isDependent() && "Non-dependent template isn't a declaration?");
5598 if (Template->isInvalidDecl())
5601 // C++0x [temp.arg.template]p1:
5602 // A template-argument for a template template-parameter shall be
5603 // the name of a class template or an alias template, expressed as an
5604 // id-expression. When the template-argument names a class template, only
5605 // primary class templates are considered when matching the
5606 // template template argument with the corresponding parameter;
5607 // partial specializations are not considered even if their
5608 // parameter lists match that of the template template parameter.
5610 // Note that we also allow template template parameters here, which
5611 // will happen when we are dealing with, e.g., class template
5612 // partial specializations.
5613 if (!isa<ClassTemplateDecl>(Template) &&
5614 !isa<TemplateTemplateParmDecl>(Template) &&
5615 !isa<TypeAliasTemplateDecl>(Template) &&
5616 !isa<BuiltinTemplateDecl>(Template)) {
5617 assert(isa<FunctionTemplateDecl>(Template) &&
5618 "Only function templates are possible here");
5619 Diag(Arg.getLocation(), diag::err_template_arg_not_valid_template);
5620 Diag(Template->getLocation(), diag::note_template_arg_refers_here_func)
5624 TemplateParameterList *Params = Param->getTemplateParameters();
5625 if (Param->isExpandedParameterPack())
5626 Params = Param->getExpansionTemplateParameters(ArgumentPackIndex);
5628 // C++1z [temp.arg.template]p3: (DR 150)
5629 // A template-argument matches a template template-parameter P when P
5630 // is at least as specialized as the template-argument A.
5631 if (getLangOpts().RelaxedTemplateTemplateArgs) {
5632 // Quick check for the common case:
5633 // If P contains a parameter pack, then A [...] matches P if each of A's
5634 // template parameters matches the corresponding template parameter in
5635 // the template-parameter-list of P.
5636 if (TemplateParameterListsAreEqual(
5637 Template->getTemplateParameters(), Params, false,
5638 TPL_TemplateTemplateArgumentMatch, Arg.getLocation()))
5641 if (isTemplateTemplateParameterAtLeastAsSpecializedAs(Params, Template,
5644 // FIXME: Produce better diagnostics for deduction failures.
5647 return !TemplateParameterListsAreEqual(Template->getTemplateParameters(),
5650 TPL_TemplateTemplateArgumentMatch,
5654 /// \brief Given a non-type template argument that refers to a
5655 /// declaration and the type of its corresponding non-type template
5656 /// parameter, produce an expression that properly refers to that
5659 Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
5661 SourceLocation Loc) {
5662 // C++ [temp.param]p8:
5664 // A non-type template-parameter of type "array of T" or
5665 // "function returning T" is adjusted to be of type "pointer to
5666 // T" or "pointer to function returning T", respectively.
5667 if (ParamType->isArrayType())
5668 ParamType = Context.getArrayDecayedType(ParamType);
5669 else if (ParamType->isFunctionType())
5670 ParamType = Context.getPointerType(ParamType);
5672 // For a NULL non-type template argument, return nullptr casted to the
5673 // parameter's type.
5674 if (Arg.getKind() == TemplateArgument::NullPtr) {
5675 return ImpCastExprToType(
5676 new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc),
5678 ParamType->getAs<MemberPointerType>()
5679 ? CK_NullToMemberPointer
5680 : CK_NullToPointer);
5682 assert(Arg.getKind() == TemplateArgument::Declaration &&
5683 "Only declaration template arguments permitted here");
5685 ValueDecl *VD = cast<ValueDecl>(Arg.getAsDecl());
5687 if (VD->getDeclContext()->isRecord() &&
5688 (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD) ||
5689 isa<IndirectFieldDecl>(VD))) {
5690 // If the value is a class member, we might have a pointer-to-member.
5691 // Determine whether the non-type template template parameter is of
5692 // pointer-to-member type. If so, we need to build an appropriate
5693 // expression for a pointer-to-member, since a "normal" DeclRefExpr
5694 // would refer to the member itself.
5695 if (ParamType->isMemberPointerType()) {
5697 = Context.getTypeDeclType(cast<RecordDecl>(VD->getDeclContext()));
5698 NestedNameSpecifier *Qualifier
5699 = NestedNameSpecifier::Create(Context, nullptr, false,
5700 ClassType.getTypePtr());
5702 SS.MakeTrivial(Context, Qualifier, Loc);
5704 // The actual value-ness of this is unimportant, but for
5705 // internal consistency's sake, references to instance methods
5707 ExprValueKind VK = VK_LValue;
5708 if (isa<CXXMethodDecl>(VD) && cast<CXXMethodDecl>(VD)->isInstance())
5711 ExprResult RefExpr = BuildDeclRefExpr(VD,
5712 VD->getType().getNonReferenceType(),
5716 if (RefExpr.isInvalid())
5719 RefExpr = CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
5721 // We might need to perform a trailing qualification conversion, since
5722 // the element type on the parameter could be more qualified than the
5723 // element type in the expression we constructed.
5724 bool ObjCLifetimeConversion;
5725 if (IsQualificationConversion(((Expr*) RefExpr.get())->getType(),
5726 ParamType.getUnqualifiedType(), false,
5727 ObjCLifetimeConversion))
5728 RefExpr = ImpCastExprToType(RefExpr.get(), ParamType.getUnqualifiedType(), CK_NoOp);
5730 assert(!RefExpr.isInvalid() &&
5731 Context.hasSameType(((Expr*) RefExpr.get())->getType(),
5732 ParamType.getUnqualifiedType()));
5737 QualType T = VD->getType().getNonReferenceType();
5739 if (ParamType->isPointerType()) {
5740 // When the non-type template parameter is a pointer, take the
5741 // address of the declaration.
5742 ExprResult RefExpr = BuildDeclRefExpr(VD, T, VK_LValue, Loc);
5743 if (RefExpr.isInvalid())
5746 if (T->isFunctionType() || T->isArrayType()) {
5747 // Decay functions and arrays.
5748 RefExpr = DefaultFunctionArrayConversion(RefExpr.get());
5749 if (RefExpr.isInvalid())
5755 // Take the address of everything else
5756 return CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
5759 ExprValueKind VK = VK_RValue;
5761 // If the non-type template parameter has reference type, qualify the
5762 // resulting declaration reference with the extra qualifiers on the
5763 // type that the reference refers to.
5764 if (const ReferenceType *TargetRef = ParamType->getAs<ReferenceType>()) {
5766 T = Context.getQualifiedType(T,
5767 TargetRef->getPointeeType().getQualifiers());
5768 } else if (isa<FunctionDecl>(VD)) {
5769 // References to functions are always lvalues.
5773 return BuildDeclRefExpr(VD, T, VK, Loc);
5776 /// \brief Construct a new expression that refers to the given
5777 /// integral template argument with the given source-location
5780 /// This routine takes care of the mapping from an integral template
5781 /// argument (which may have any integral type) to the appropriate
5784 Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg,
5785 SourceLocation Loc) {
5786 assert(Arg.getKind() == TemplateArgument::Integral &&
5787 "Operation is only valid for integral template arguments");
5788 QualType OrigT = Arg.getIntegralType();
5790 // If this is an enum type that we're instantiating, we need to use an integer
5791 // type the same size as the enumerator. We don't want to build an
5792 // IntegerLiteral with enum type. The integer type of an enum type can be of
5793 // any integral type with C++11 enum classes, make sure we create the right
5794 // type of literal for it.
5796 if (const EnumType *ET = OrigT->getAs<EnumType>())
5797 T = ET->getDecl()->getIntegerType();
5800 if (T->isAnyCharacterType()) {
5801 // This does not need to handle u8 character literals because those are
5802 // of type char, and so can also be covered by an ASCII character literal.
5803 CharacterLiteral::CharacterKind Kind;
5804 if (T->isWideCharType())
5805 Kind = CharacterLiteral::Wide;
5806 else if (T->isChar16Type())
5807 Kind = CharacterLiteral::UTF16;
5808 else if (T->isChar32Type())
5809 Kind = CharacterLiteral::UTF32;
5811 Kind = CharacterLiteral::Ascii;
5813 E = new (Context) CharacterLiteral(Arg.getAsIntegral().getZExtValue(),
5815 } else if (T->isBooleanType()) {
5816 E = new (Context) CXXBoolLiteralExpr(Arg.getAsIntegral().getBoolValue(),
5818 } else if (T->isNullPtrType()) {
5819 E = new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
5821 E = IntegerLiteral::Create(Context, Arg.getAsIntegral(), T, Loc);
5824 if (OrigT->isEnumeralType()) {
5825 // FIXME: This is a hack. We need a better way to handle substituted
5826 // non-type template parameters.
5827 E = CStyleCastExpr::Create(Context, OrigT, VK_RValue, CK_IntegralCast, E,
5829 Context.getTrivialTypeSourceInfo(OrigT, Loc),
5836 /// \brief Match two template parameters within template parameter lists.
5837 static bool MatchTemplateParameterKind(Sema &S, NamedDecl *New, NamedDecl *Old,
5839 Sema::TemplateParameterListEqualKind Kind,
5840 SourceLocation TemplateArgLoc) {
5841 // Check the actual kind (type, non-type, template).
5842 if (Old->getKind() != New->getKind()) {
5844 unsigned NextDiag = diag::err_template_param_different_kind;
5845 if (TemplateArgLoc.isValid()) {
5846 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
5847 NextDiag = diag::note_template_param_different_kind;
5849 S.Diag(New->getLocation(), NextDiag)
5850 << (Kind != Sema::TPL_TemplateMatch);
5851 S.Diag(Old->getLocation(), diag::note_template_prev_declaration)
5852 << (Kind != Sema::TPL_TemplateMatch);
5858 // Check that both are parameter packs or neither are parameter packs.
5859 // However, if we are matching a template template argument to a
5860 // template template parameter, the template template parameter can have
5861 // a parameter pack where the template template argument does not.
5862 if (Old->isTemplateParameterPack() != New->isTemplateParameterPack() &&
5863 !(Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
5864 Old->isTemplateParameterPack())) {
5866 unsigned NextDiag = diag::err_template_parameter_pack_non_pack;
5867 if (TemplateArgLoc.isValid()) {
5868 S.Diag(TemplateArgLoc,
5869 diag::err_template_arg_template_params_mismatch);
5870 NextDiag = diag::note_template_parameter_pack_non_pack;
5873 unsigned ParamKind = isa<TemplateTypeParmDecl>(New)? 0
5874 : isa<NonTypeTemplateParmDecl>(New)? 1
5876 S.Diag(New->getLocation(), NextDiag)
5877 << ParamKind << New->isParameterPack();
5878 S.Diag(Old->getLocation(), diag::note_template_parameter_pack_here)
5879 << ParamKind << Old->isParameterPack();
5885 // For non-type template parameters, check the type of the parameter.
5886 if (NonTypeTemplateParmDecl *OldNTTP
5887 = dyn_cast<NonTypeTemplateParmDecl>(Old)) {
5888 NonTypeTemplateParmDecl *NewNTTP = cast<NonTypeTemplateParmDecl>(New);
5890 // If we are matching a template template argument to a template
5891 // template parameter and one of the non-type template parameter types
5892 // is dependent, then we must wait until template instantiation time
5893 // to actually compare the arguments.
5894 if (Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
5895 (OldNTTP->getType()->isDependentType() ||
5896 NewNTTP->getType()->isDependentType()))
5899 if (!S.Context.hasSameType(OldNTTP->getType(), NewNTTP->getType())) {
5901 unsigned NextDiag = diag::err_template_nontype_parm_different_type;
5902 if (TemplateArgLoc.isValid()) {
5903 S.Diag(TemplateArgLoc,
5904 diag::err_template_arg_template_params_mismatch);
5905 NextDiag = diag::note_template_nontype_parm_different_type;
5907 S.Diag(NewNTTP->getLocation(), NextDiag)
5908 << NewNTTP->getType()
5909 << (Kind != Sema::TPL_TemplateMatch);
5910 S.Diag(OldNTTP->getLocation(),
5911 diag::note_template_nontype_parm_prev_declaration)
5912 << OldNTTP->getType();
5921 // For template template parameters, check the template parameter types.
5922 // The template parameter lists of template template
5923 // parameters must agree.
5924 if (TemplateTemplateParmDecl *OldTTP
5925 = dyn_cast<TemplateTemplateParmDecl>(Old)) {
5926 TemplateTemplateParmDecl *NewTTP = cast<TemplateTemplateParmDecl>(New);
5927 return S.TemplateParameterListsAreEqual(NewTTP->getTemplateParameters(),
5928 OldTTP->getTemplateParameters(),
5930 (Kind == Sema::TPL_TemplateMatch
5931 ? Sema::TPL_TemplateTemplateParmMatch
5939 /// \brief Diagnose a known arity mismatch when comparing template argument
5942 void DiagnoseTemplateParameterListArityMismatch(Sema &S,
5943 TemplateParameterList *New,
5944 TemplateParameterList *Old,
5945 Sema::TemplateParameterListEqualKind Kind,
5946 SourceLocation TemplateArgLoc) {
5947 unsigned NextDiag = diag::err_template_param_list_different_arity;
5948 if (TemplateArgLoc.isValid()) {
5949 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
5950 NextDiag = diag::note_template_param_list_different_arity;
5952 S.Diag(New->getTemplateLoc(), NextDiag)
5953 << (New->size() > Old->size())
5954 << (Kind != Sema::TPL_TemplateMatch)
5955 << SourceRange(New->getTemplateLoc(), New->getRAngleLoc());
5956 S.Diag(Old->getTemplateLoc(), diag::note_template_prev_declaration)
5957 << (Kind != Sema::TPL_TemplateMatch)
5958 << SourceRange(Old->getTemplateLoc(), Old->getRAngleLoc());
5961 /// \brief Determine whether the given template parameter lists are
5964 /// \param New The new template parameter list, typically written in the
5965 /// source code as part of a new template declaration.
5967 /// \param Old The old template parameter list, typically found via
5968 /// name lookup of the template declared with this template parameter
5971 /// \param Complain If true, this routine will produce a diagnostic if
5972 /// the template parameter lists are not equivalent.
5974 /// \param Kind describes how we are to match the template parameter lists.
5976 /// \param TemplateArgLoc If this source location is valid, then we
5977 /// are actually checking the template parameter list of a template
5978 /// argument (New) against the template parameter list of its
5979 /// corresponding template template parameter (Old). We produce
5980 /// slightly different diagnostics in this scenario.
5982 /// \returns True if the template parameter lists are equal, false
5985 Sema::TemplateParameterListsAreEqual(TemplateParameterList *New,
5986 TemplateParameterList *Old,
5988 TemplateParameterListEqualKind Kind,
5989 SourceLocation TemplateArgLoc) {
5990 if (Old->size() != New->size() && Kind != TPL_TemplateTemplateArgumentMatch) {
5992 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
5998 // C++0x [temp.arg.template]p3:
5999 // A template-argument matches a template template-parameter (call it P)
6000 // when each of the template parameters in the template-parameter-list of
6001 // the template-argument's corresponding class template or alias template
6002 // (call it A) matches the corresponding template parameter in the
6003 // template-parameter-list of P. [...]
6004 TemplateParameterList::iterator NewParm = New->begin();
6005 TemplateParameterList::iterator NewParmEnd = New->end();
6006 for (TemplateParameterList::iterator OldParm = Old->begin(),
6007 OldParmEnd = Old->end();
6008 OldParm != OldParmEnd; ++OldParm) {
6009 if (Kind != TPL_TemplateTemplateArgumentMatch ||
6010 !(*OldParm)->isTemplateParameterPack()) {
6011 if (NewParm == NewParmEnd) {
6013 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
6019 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
6020 Kind, TemplateArgLoc))
6027 // C++0x [temp.arg.template]p3:
6028 // [...] When P's template- parameter-list contains a template parameter
6029 // pack (14.5.3), the template parameter pack will match zero or more
6030 // template parameters or template parameter packs in the
6031 // template-parameter-list of A with the same type and form as the
6032 // template parameter pack in P (ignoring whether those template
6033 // parameters are template parameter packs).
6034 for (; NewParm != NewParmEnd; ++NewParm) {
6035 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
6036 Kind, TemplateArgLoc))
6041 // Make sure we exhausted all of the arguments.
6042 if (NewParm != NewParmEnd) {
6044 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
6053 /// \brief Check whether a template can be declared within this scope.
6055 /// If the template declaration is valid in this scope, returns
6056 /// false. Otherwise, issues a diagnostic and returns true.
6058 Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) {
6062 // Find the nearest enclosing declaration scope.
6063 while ((S->getFlags() & Scope::DeclScope) == 0 ||
6064 (S->getFlags() & Scope::TemplateParamScope) != 0)
6068 // A template [...] shall not have C linkage.
6069 DeclContext *Ctx = S->getEntity();
6070 if (Ctx && Ctx->isExternCContext()) {
6071 Diag(TemplateParams->getTemplateLoc(), diag::err_template_linkage)
6072 << TemplateParams->getSourceRange();
6073 if (const LinkageSpecDecl *LSD = Ctx->getExternCContext())
6074 Diag(LSD->getExternLoc(), diag::note_extern_c_begins_here);
6077 Ctx = Ctx->getRedeclContext();
6080 // A template-declaration can appear only as a namespace scope or
6081 // class scope declaration.
6083 if (Ctx->isFileContext())
6085 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Ctx)) {
6086 // C++ [temp.mem]p2:
6087 // A local class shall not have member templates.
6088 if (RD->isLocalClass())
6089 return Diag(TemplateParams->getTemplateLoc(),
6090 diag::err_template_inside_local_class)
6091 << TemplateParams->getSourceRange();
6097 return Diag(TemplateParams->getTemplateLoc(),
6098 diag::err_template_outside_namespace_or_class_scope)
6099 << TemplateParams->getSourceRange();
6102 /// \brief Determine what kind of template specialization the given declaration
6104 static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D) {
6106 return TSK_Undeclared;
6108 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D))
6109 return Record->getTemplateSpecializationKind();
6110 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D))
6111 return Function->getTemplateSpecializationKind();
6112 if (VarDecl *Var = dyn_cast<VarDecl>(D))
6113 return Var->getTemplateSpecializationKind();
6115 return TSK_Undeclared;
6118 /// \brief Check whether a specialization is well-formed in the current
6121 /// This routine determines whether a template specialization can be declared
6122 /// in the current context (C++ [temp.expl.spec]p2).
6124 /// \param S the semantic analysis object for which this check is being
6127 /// \param Specialized the entity being specialized or instantiated, which
6128 /// may be a kind of template (class template, function template, etc.) or
6129 /// a member of a class template (member function, static data member,
6132 /// \param PrevDecl the previous declaration of this entity, if any.
6134 /// \param Loc the location of the explicit specialization or instantiation of
6137 /// \param IsPartialSpecialization whether this is a partial specialization of
6138 /// a class template.
6140 /// \returns true if there was an error that we cannot recover from, false
6142 static bool CheckTemplateSpecializationScope(Sema &S,
6143 NamedDecl *Specialized,
6144 NamedDecl *PrevDecl,
6146 bool IsPartialSpecialization) {
6147 // Keep these "kind" numbers in sync with the %select statements in the
6148 // various diagnostics emitted by this routine.
6150 if (isa<ClassTemplateDecl>(Specialized))
6151 EntityKind = IsPartialSpecialization? 1 : 0;
6152 else if (isa<VarTemplateDecl>(Specialized))
6153 EntityKind = IsPartialSpecialization ? 3 : 2;
6154 else if (isa<FunctionTemplateDecl>(Specialized))
6156 else if (isa<CXXMethodDecl>(Specialized))
6158 else if (isa<VarDecl>(Specialized))
6160 else if (isa<RecordDecl>(Specialized))
6162 else if (isa<EnumDecl>(Specialized) && S.getLangOpts().CPlusPlus11)
6165 S.Diag(Loc, diag::err_template_spec_unknown_kind)
6166 << S.getLangOpts().CPlusPlus11;
6167 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
6171 // C++ [temp.expl.spec]p2:
6172 // An explicit specialization shall be declared in the namespace
6173 // of which the template is a member, or, for member templates, in
6174 // the namespace of which the enclosing class or enclosing class
6175 // template is a member. An explicit specialization of a member
6176 // function, member class or static data member of a class
6177 // template shall be declared in the namespace of which the class
6178 // template is a member. Such a declaration may also be a
6179 // definition. If the declaration is not a definition, the
6180 // specialization may be defined later in the name- space in which
6181 // the explicit specialization was declared, or in a namespace
6182 // that encloses the one in which the explicit specialization was
6184 if (S.CurContext->getRedeclContext()->isFunctionOrMethod()) {
6185 S.Diag(Loc, diag::err_template_spec_decl_function_scope)
6190 if (S.CurContext->isRecord() && !IsPartialSpecialization) {
6191 if (S.getLangOpts().MicrosoftExt) {
6192 // Do not warn for class scope explicit specialization during
6193 // instantiation, warning was already emitted during pattern
6194 // semantic analysis.
6195 if (!S.ActiveTemplateInstantiations.size())
6196 S.Diag(Loc, diag::ext_function_specialization_in_class)
6199 S.Diag(Loc, diag::err_template_spec_decl_class_scope)
6205 if (S.CurContext->isRecord() &&
6206 !S.CurContext->Equals(Specialized->getDeclContext())) {
6207 // Make sure that we're specializing in the right record context.
6208 // Otherwise, things can go horribly wrong.
6209 S.Diag(Loc, diag::err_template_spec_decl_class_scope)
6214 // C++ [temp.class.spec]p6:
6215 // A class template partial specialization may be declared or redeclared
6216 // in any namespace scope in which its definition may be defined (14.5.1
6218 DeclContext *SpecializedContext
6219 = Specialized->getDeclContext()->getEnclosingNamespaceContext();
6220 DeclContext *DC = S.CurContext->getEnclosingNamespaceContext();
6222 // Make sure that this redeclaration (or definition) occurs in an enclosing
6224 // Note that HandleDeclarator() performs this check for explicit
6225 // specializations of function templates, static data members, and member
6226 // functions, so we skip the check here for those kinds of entities.
6227 // FIXME: HandleDeclarator's diagnostics aren't quite as good, though.
6228 // Should we refactor that check, so that it occurs later?
6229 if (!DC->Encloses(SpecializedContext) &&
6230 !(isa<FunctionTemplateDecl>(Specialized) ||
6231 isa<FunctionDecl>(Specialized) ||
6232 isa<VarTemplateDecl>(Specialized) ||
6233 isa<VarDecl>(Specialized))) {
6234 if (isa<TranslationUnitDecl>(SpecializedContext))
6235 S.Diag(Loc, diag::err_template_spec_redecl_global_scope)
6236 << EntityKind << Specialized;
6237 else if (isa<NamespaceDecl>(SpecializedContext)) {
6238 int Diag = diag::err_template_spec_redecl_out_of_scope;
6239 if (S.getLangOpts().MicrosoftExt)
6240 Diag = diag::ext_ms_template_spec_redecl_out_of_scope;
6241 S.Diag(Loc, Diag) << EntityKind << Specialized
6242 << cast<NamedDecl>(SpecializedContext);
6244 llvm_unreachable("unexpected namespace context for specialization");
6246 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
6247 } else if ((!PrevDecl ||
6248 getTemplateSpecializationKind(PrevDecl) == TSK_Undeclared ||
6249 getTemplateSpecializationKind(PrevDecl) ==
6250 TSK_ImplicitInstantiation)) {
6251 // C++ [temp.exp.spec]p2:
6252 // An explicit specialization shall be declared in the namespace of which
6253 // the template is a member, or, for member templates, in the namespace
6254 // of which the enclosing class or enclosing class template is a member.
6255 // An explicit specialization of a member function, member class or
6256 // static data member of a class template shall be declared in the
6257 // namespace of which the class template is a member.
6259 // C++11 [temp.expl.spec]p2:
6260 // An explicit specialization shall be declared in a namespace enclosing
6261 // the specialized template.
6262 // C++11 [temp.explicit]p3:
6263 // An explicit instantiation shall appear in an enclosing namespace of its
6265 if (!DC->InEnclosingNamespaceSetOf(SpecializedContext)) {
6266 bool IsCPlusPlus11Extension = DC->Encloses(SpecializedContext);
6267 if (isa<TranslationUnitDecl>(SpecializedContext)) {
6268 assert(!IsCPlusPlus11Extension &&
6269 "DC encloses TU but isn't in enclosing namespace set");
6270 S.Diag(Loc, diag::err_template_spec_decl_out_of_scope_global)
6271 << EntityKind << Specialized;
6272 } else if (isa<NamespaceDecl>(SpecializedContext)) {
6274 if (!IsCPlusPlus11Extension)
6275 Diag = diag::err_template_spec_decl_out_of_scope;
6276 else if (!S.getLangOpts().CPlusPlus11)
6277 Diag = diag::ext_template_spec_decl_out_of_scope;
6279 Diag = diag::warn_cxx98_compat_template_spec_decl_out_of_scope;
6281 << EntityKind << Specialized << cast<NamedDecl>(SpecializedContext);
6284 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
6291 static SourceRange findTemplateParameterInType(unsigned Depth, Expr *E) {
6292 if (!E->isTypeDependent())
6293 return SourceLocation();
6294 DependencyChecker Checker(Depth, /*IgnoreNonTypeDependent*/true);
6295 Checker.TraverseStmt(E);
6296 if (Checker.MatchLoc.isInvalid())
6297 return E->getSourceRange();
6298 return Checker.MatchLoc;
6301 static SourceRange findTemplateParameter(unsigned Depth, TypeLoc TL) {
6302 if (!TL.getType()->isDependentType())
6303 return SourceLocation();
6304 DependencyChecker Checker(Depth, /*IgnoreNonTypeDependent*/true);
6305 Checker.TraverseTypeLoc(TL);
6306 if (Checker.MatchLoc.isInvalid())
6307 return TL.getSourceRange();
6308 return Checker.MatchLoc;
6311 /// \brief Subroutine of Sema::CheckTemplatePartialSpecializationArgs
6312 /// that checks non-type template partial specialization arguments.
6313 static bool CheckNonTypeTemplatePartialSpecializationArgs(
6314 Sema &S, SourceLocation TemplateNameLoc, NonTypeTemplateParmDecl *Param,
6315 const TemplateArgument *Args, unsigned NumArgs, bool IsDefaultArgument) {
6316 for (unsigned I = 0; I != NumArgs; ++I) {
6317 if (Args[I].getKind() == TemplateArgument::Pack) {
6318 if (CheckNonTypeTemplatePartialSpecializationArgs(
6319 S, TemplateNameLoc, Param, Args[I].pack_begin(),
6320 Args[I].pack_size(), IsDefaultArgument))
6326 if (Args[I].getKind() != TemplateArgument::Expression)
6329 Expr *ArgExpr = Args[I].getAsExpr();
6331 // We can have a pack expansion of any of the bullets below.
6332 if (PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(ArgExpr))
6333 ArgExpr = Expansion->getPattern();
6335 // Strip off any implicit casts we added as part of type checking.
6336 while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
6337 ArgExpr = ICE->getSubExpr();
6339 // C++ [temp.class.spec]p8:
6340 // A non-type argument is non-specialized if it is the name of a
6341 // non-type parameter. All other non-type arguments are
6344 // Below, we check the two conditions that only apply to
6345 // specialized non-type arguments, so skip any non-specialized
6347 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ArgExpr))
6348 if (isa<NonTypeTemplateParmDecl>(DRE->getDecl()))
6351 // C++ [temp.class.spec]p9:
6352 // Within the argument list of a class template partial
6353 // specialization, the following restrictions apply:
6354 // -- A partially specialized non-type argument expression
6355 // shall not involve a template parameter of the partial
6356 // specialization except when the argument expression is a
6357 // simple identifier.
6358 // -- The type of a template parameter corresponding to a
6359 // specialized non-type argument shall not be dependent on a
6360 // parameter of the specialization.
6361 // DR1315 removes the first bullet, leaving an incoherent set of rules.
6362 // We implement a compromise between the original rules and DR1315:
6363 // -- A specialized non-type template argument shall not be
6364 // type-dependent and the corresponding template parameter
6365 // shall have a non-dependent type.
6366 SourceRange ParamUseRange =
6367 findTemplateParameterInType(Param->getDepth(), ArgExpr);
6368 if (ParamUseRange.isValid()) {
6369 if (IsDefaultArgument) {
6370 S.Diag(TemplateNameLoc,
6371 diag::err_dependent_non_type_arg_in_partial_spec);
6372 S.Diag(ParamUseRange.getBegin(),
6373 diag::note_dependent_non_type_default_arg_in_partial_spec)
6376 S.Diag(ParamUseRange.getBegin(),
6377 diag::err_dependent_non_type_arg_in_partial_spec)
6383 ParamUseRange = findTemplateParameter(
6384 Param->getDepth(), Param->getTypeSourceInfo()->getTypeLoc());
6385 if (ParamUseRange.isValid()) {
6386 S.Diag(IsDefaultArgument ? TemplateNameLoc : ArgExpr->getLocStart(),
6387 diag::err_dependent_typed_non_type_arg_in_partial_spec)
6388 << Param->getType();
6389 S.Diag(Param->getLocation(), diag::note_template_param_here)
6390 << (IsDefaultArgument ? ParamUseRange : SourceRange())
6399 /// \brief Check the non-type template arguments of a class template
6400 /// partial specialization according to C++ [temp.class.spec]p9.
6402 /// \param TemplateNameLoc the location of the template name.
6403 /// \param PrimaryTemplate the template parameters of the primary class
6405 /// \param NumExplicit the number of explicitly-specified template arguments.
6406 /// \param TemplateArgs the template arguments of the class template
6407 /// partial specialization.
6409 /// \returns \c true if there was an error, \c false otherwise.
6410 bool Sema::CheckTemplatePartialSpecializationArgs(
6411 SourceLocation TemplateNameLoc, TemplateDecl *PrimaryTemplate,
6412 unsigned NumExplicit, ArrayRef<TemplateArgument> TemplateArgs) {
6413 // We have to be conservative when checking a template in a dependent
6415 if (PrimaryTemplate->getDeclContext()->isDependentContext())
6418 TemplateParameterList *TemplateParams =
6419 PrimaryTemplate->getTemplateParameters();
6420 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
6421 NonTypeTemplateParmDecl *Param
6422 = dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(I));
6426 if (CheckNonTypeTemplatePartialSpecializationArgs(*this, TemplateNameLoc,
6427 Param, &TemplateArgs[I],
6428 1, I >= NumExplicit))
6436 Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec,
6438 SourceLocation KWLoc,
6439 SourceLocation ModulePrivateLoc,
6440 TemplateIdAnnotation &TemplateId,
6441 AttributeList *Attr,
6442 MultiTemplateParamsArg
6443 TemplateParameterLists,
6444 SkipBodyInfo *SkipBody) {
6445 assert(TUK != TUK_Reference && "References are not specializations");
6447 CXXScopeSpec &SS = TemplateId.SS;
6449 // NOTE: KWLoc is the location of the tag keyword. This will instead
6450 // store the location of the outermost template keyword in the declaration.
6451 SourceLocation TemplateKWLoc = TemplateParameterLists.size() > 0
6452 ? TemplateParameterLists[0]->getTemplateLoc() : KWLoc;
6453 SourceLocation TemplateNameLoc = TemplateId.TemplateNameLoc;
6454 SourceLocation LAngleLoc = TemplateId.LAngleLoc;
6455 SourceLocation RAngleLoc = TemplateId.RAngleLoc;
6457 // Find the class template we're specializing
6458 TemplateName Name = TemplateId.Template.get();
6459 ClassTemplateDecl *ClassTemplate
6460 = dyn_cast_or_null<ClassTemplateDecl>(Name.getAsTemplateDecl());
6462 if (!ClassTemplate) {
6463 Diag(TemplateNameLoc, diag::err_not_class_template_specialization)
6464 << (Name.getAsTemplateDecl() &&
6465 isa<TemplateTemplateParmDecl>(Name.getAsTemplateDecl()));
6469 bool isExplicitSpecialization = false;
6470 bool isPartialSpecialization = false;
6472 // Check the validity of the template headers that introduce this
6474 // FIXME: We probably shouldn't complain about these headers for
6475 // friend declarations.
6476 bool Invalid = false;
6477 TemplateParameterList *TemplateParams =
6478 MatchTemplateParametersToScopeSpecifier(
6479 KWLoc, TemplateNameLoc, SS, &TemplateId,
6480 TemplateParameterLists, TUK == TUK_Friend, isExplicitSpecialization,
6485 if (TemplateParams && TemplateParams->size() > 0) {
6486 isPartialSpecialization = true;
6488 if (TUK == TUK_Friend) {
6489 Diag(KWLoc, diag::err_partial_specialization_friend)
6490 << SourceRange(LAngleLoc, RAngleLoc);
6494 // C++ [temp.class.spec]p10:
6495 // The template parameter list of a specialization shall not
6496 // contain default template argument values.
6497 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
6498 Decl *Param = TemplateParams->getParam(I);
6499 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) {
6500 if (TTP->hasDefaultArgument()) {
6501 Diag(TTP->getDefaultArgumentLoc(),
6502 diag::err_default_arg_in_partial_spec);
6503 TTP->removeDefaultArgument();
6505 } else if (NonTypeTemplateParmDecl *NTTP
6506 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
6507 if (Expr *DefArg = NTTP->getDefaultArgument()) {
6508 Diag(NTTP->getDefaultArgumentLoc(),
6509 diag::err_default_arg_in_partial_spec)
6510 << DefArg->getSourceRange();
6511 NTTP->removeDefaultArgument();
6514 TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(Param);
6515 if (TTP->hasDefaultArgument()) {
6516 Diag(TTP->getDefaultArgument().getLocation(),
6517 diag::err_default_arg_in_partial_spec)
6518 << TTP->getDefaultArgument().getSourceRange();
6519 TTP->removeDefaultArgument();
6523 } else if (TemplateParams) {
6524 if (TUK == TUK_Friend)
6525 Diag(KWLoc, diag::err_template_spec_friend)
6526 << FixItHint::CreateRemoval(
6527 SourceRange(TemplateParams->getTemplateLoc(),
6528 TemplateParams->getRAngleLoc()))
6529 << SourceRange(LAngleLoc, RAngleLoc);
6531 isExplicitSpecialization = true;
6533 assert(TUK == TUK_Friend && "should have a 'template<>' for this decl");
6536 // Check that the specialization uses the same tag kind as the
6537 // original template.
6538 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
6539 assert(Kind != TTK_Enum && "Invalid enum tag in class template spec!");
6540 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
6541 Kind, TUK == TUK_Definition, KWLoc,
6542 ClassTemplate->getIdentifier())) {
6543 Diag(KWLoc, diag::err_use_with_wrong_tag)
6545 << FixItHint::CreateReplacement(KWLoc,
6546 ClassTemplate->getTemplatedDecl()->getKindName());
6547 Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
6548 diag::note_previous_use);
6549 Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
6552 // Translate the parser's template argument list in our AST format.
6553 TemplateArgumentListInfo TemplateArgs =
6554 makeTemplateArgumentListInfo(*this, TemplateId);
6556 // Check for unexpanded parameter packs in any of the template arguments.
6557 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
6558 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
6559 UPPC_PartialSpecialization))
6562 // Check that the template argument list is well-formed for this
6564 SmallVector<TemplateArgument, 4> Converted;
6565 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
6566 TemplateArgs, false, Converted))
6569 // Find the class template (partial) specialization declaration that
6570 // corresponds to these arguments.
6571 if (isPartialSpecialization) {
6572 if (CheckTemplatePartialSpecializationArgs(TemplateNameLoc, ClassTemplate,
6573 TemplateArgs.size(), Converted))
6576 // FIXME: Move this to CheckTemplatePartialSpecializationArgs so we
6577 // also do it during instantiation.
6578 bool InstantiationDependent;
6579 if (!Name.isDependent() &&
6580 !TemplateSpecializationType::anyDependentTemplateArguments(
6581 TemplateArgs.arguments(), InstantiationDependent)) {
6582 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
6583 << ClassTemplate->getDeclName();
6584 isPartialSpecialization = false;
6588 void *InsertPos = nullptr;
6589 ClassTemplateSpecializationDecl *PrevDecl = nullptr;
6591 if (isPartialSpecialization)
6592 // FIXME: Template parameter list matters, too
6593 PrevDecl = ClassTemplate->findPartialSpecialization(Converted, InsertPos);
6595 PrevDecl = ClassTemplate->findSpecialization(Converted, InsertPos);
6597 ClassTemplateSpecializationDecl *Specialization = nullptr;
6599 // Check whether we can declare a class template specialization in
6600 // the current scope.
6601 if (TUK != TUK_Friend &&
6602 CheckTemplateSpecializationScope(*this, ClassTemplate, PrevDecl,
6604 isPartialSpecialization))
6607 // The canonical type
6609 if (isPartialSpecialization) {
6610 // Build the canonical type that describes the converted template
6611 // arguments of the class template partial specialization.
6612 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
6613 CanonType = Context.getTemplateSpecializationType(CanonTemplate,
6616 if (Context.hasSameType(CanonType,
6617 ClassTemplate->getInjectedClassNameSpecialization())) {
6618 // C++ [temp.class.spec]p9b3:
6620 // -- The argument list of the specialization shall not be identical
6621 // to the implicit argument list of the primary template.
6623 // This rule has since been removed, because it's redundant given DR1495,
6624 // but we keep it because it produces better diagnostics and recovery.
6625 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
6626 << /*class template*/0 << (TUK == TUK_Definition)
6627 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
6628 return CheckClassTemplate(S, TagSpec, TUK, KWLoc, SS,
6629 ClassTemplate->getIdentifier(),
6633 AS_none, /*ModulePrivateLoc=*/SourceLocation(),
6634 /*FriendLoc*/SourceLocation(),
6635 TemplateParameterLists.size() - 1,
6636 TemplateParameterLists.data());
6639 // Create a new class template partial specialization declaration node.
6640 ClassTemplatePartialSpecializationDecl *PrevPartial
6641 = cast_or_null<ClassTemplatePartialSpecializationDecl>(PrevDecl);
6642 ClassTemplatePartialSpecializationDecl *Partial
6643 = ClassTemplatePartialSpecializationDecl::Create(Context, Kind,
6644 ClassTemplate->getDeclContext(),
6645 KWLoc, TemplateNameLoc,
6652 SetNestedNameSpecifier(Partial, SS);
6653 if (TemplateParameterLists.size() > 1 && SS.isSet()) {
6654 Partial->setTemplateParameterListsInfo(
6655 Context, TemplateParameterLists.drop_back(1));
6659 ClassTemplate->AddPartialSpecialization(Partial, InsertPos);
6660 Specialization = Partial;
6662 // If we are providing an explicit specialization of a member class
6663 // template specialization, make a note of that.
6664 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
6665 PrevPartial->setMemberSpecialization();
6667 CheckTemplatePartialSpecialization(Partial);
6669 // Create a new class template specialization declaration node for
6670 // this explicit specialization or friend declaration.
6672 = ClassTemplateSpecializationDecl::Create(Context, Kind,
6673 ClassTemplate->getDeclContext(),
6674 KWLoc, TemplateNameLoc,
6678 SetNestedNameSpecifier(Specialization, SS);
6679 if (TemplateParameterLists.size() > 0) {
6680 Specialization->setTemplateParameterListsInfo(Context,
6681 TemplateParameterLists);
6685 ClassTemplate->AddSpecialization(Specialization, InsertPos);
6687 if (CurContext->isDependentContext()) {
6688 // -fms-extensions permits specialization of nested classes without
6689 // fully specializing the outer class(es).
6690 assert(getLangOpts().MicrosoftExt &&
6691 "Only possible with -fms-extensions!");
6692 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
6693 CanonType = Context.getTemplateSpecializationType(
6694 CanonTemplate, Converted);
6696 CanonType = Context.getTypeDeclType(Specialization);
6700 // C++ [temp.expl.spec]p6:
6701 // If a template, a member template or the member of a class template is
6702 // explicitly specialized then that specialization shall be declared
6703 // before the first use of that specialization that would cause an implicit
6704 // instantiation to take place, in every translation unit in which such a
6705 // use occurs; no diagnostic is required.
6706 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
6708 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6709 // Is there any previous explicit specialization declaration?
6710 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
6717 SourceRange Range(TemplateNameLoc, RAngleLoc);
6718 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
6719 << Context.getTypeDeclType(Specialization) << Range;
6721 Diag(PrevDecl->getPointOfInstantiation(),
6722 diag::note_instantiation_required_here)
6723 << (PrevDecl->getTemplateSpecializationKind()
6724 != TSK_ImplicitInstantiation);
6729 // If this is not a friend, note that this is an explicit specialization.
6730 if (TUK != TUK_Friend)
6731 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
6733 // Check that this isn't a redefinition of this specialization.
6734 if (TUK == TUK_Definition) {
6735 RecordDecl *Def = Specialization->getDefinition();
6736 NamedDecl *Hidden = nullptr;
6737 if (Def && SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
6738 SkipBody->ShouldSkip = true;
6739 makeMergedDefinitionVisible(Hidden, KWLoc);
6740 // From here on out, treat this as just a redeclaration.
6741 TUK = TUK_Declaration;
6743 SourceRange Range(TemplateNameLoc, RAngleLoc);
6744 Diag(TemplateNameLoc, diag::err_redefinition) << Specialization << Range;
6745 Diag(Def->getLocation(), diag::note_previous_definition);
6746 Specialization->setInvalidDecl();
6752 ProcessDeclAttributeList(S, Specialization, Attr);
6754 // Add alignment attributes if necessary; these attributes are checked when
6755 // the ASTContext lays out the structure.
6756 if (TUK == TUK_Definition) {
6757 AddAlignmentAttributesForRecord(Specialization);
6758 AddMsStructLayoutForRecord(Specialization);
6761 if (ModulePrivateLoc.isValid())
6762 Diag(Specialization->getLocation(), diag::err_module_private_specialization)
6763 << (isPartialSpecialization? 1 : 0)
6764 << FixItHint::CreateRemoval(ModulePrivateLoc);
6766 // Build the fully-sugared type for this class template
6767 // specialization as the user wrote in the specialization
6768 // itself. This means that we'll pretty-print the type retrieved
6769 // from the specialization's declaration the way that the user
6770 // actually wrote the specialization, rather than formatting the
6771 // name based on the "canonical" representation used to store the
6772 // template arguments in the specialization.
6773 TypeSourceInfo *WrittenTy
6774 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
6775 TemplateArgs, CanonType);
6776 if (TUK != TUK_Friend) {
6777 Specialization->setTypeAsWritten(WrittenTy);
6778 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
6781 // C++ [temp.expl.spec]p9:
6782 // A template explicit specialization is in the scope of the
6783 // namespace in which the template was defined.
6785 // We actually implement this paragraph where we set the semantic
6786 // context (in the creation of the ClassTemplateSpecializationDecl),
6787 // but we also maintain the lexical context where the actual
6788 // definition occurs.
6789 Specialization->setLexicalDeclContext(CurContext);
6791 // We may be starting the definition of this specialization.
6792 if (TUK == TUK_Definition)
6793 Specialization->startDefinition();
6795 if (TUK == TUK_Friend) {
6796 FriendDecl *Friend = FriendDecl::Create(Context, CurContext,
6800 Friend->setAccess(AS_public);
6801 CurContext->addDecl(Friend);
6803 // Add the specialization into its lexical context, so that it can
6804 // be seen when iterating through the list of declarations in that
6805 // context. However, specializations are not found by name lookup.
6806 CurContext->addDecl(Specialization);
6808 return Specialization;
6811 Decl *Sema::ActOnTemplateDeclarator(Scope *S,
6812 MultiTemplateParamsArg TemplateParameterLists,
6814 Decl *NewDecl = HandleDeclarator(S, D, TemplateParameterLists);
6815 ActOnDocumentableDecl(NewDecl);
6819 /// \brief Strips various properties off an implicit instantiation
6820 /// that has just been explicitly specialized.
6821 static void StripImplicitInstantiation(NamedDecl *D) {
6822 D->dropAttr<DLLImportAttr>();
6823 D->dropAttr<DLLExportAttr>();
6825 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
6826 FD->setInlineSpecified(false);
6829 /// \brief Compute the diagnostic location for an explicit instantiation
6830 // declaration or definition.
6831 static SourceLocation DiagLocForExplicitInstantiation(
6832 NamedDecl* D, SourceLocation PointOfInstantiation) {
6833 // Explicit instantiations following a specialization have no effect and
6834 // hence no PointOfInstantiation. In that case, walk decl backwards
6835 // until a valid name loc is found.
6836 SourceLocation PrevDiagLoc = PointOfInstantiation;
6837 for (Decl *Prev = D; Prev && !PrevDiagLoc.isValid();
6838 Prev = Prev->getPreviousDecl()) {
6839 PrevDiagLoc = Prev->getLocation();
6841 assert(PrevDiagLoc.isValid() &&
6842 "Explicit instantiation without point of instantiation?");
6846 /// \brief Diagnose cases where we have an explicit template specialization
6847 /// before/after an explicit template instantiation, producing diagnostics
6848 /// for those cases where they are required and determining whether the
6849 /// new specialization/instantiation will have any effect.
6851 /// \param NewLoc the location of the new explicit specialization or
6854 /// \param NewTSK the kind of the new explicit specialization or instantiation.
6856 /// \param PrevDecl the previous declaration of the entity.
6858 /// \param PrevTSK the kind of the old explicit specialization or instantiatin.
6860 /// \param PrevPointOfInstantiation if valid, indicates where the previus
6861 /// declaration was instantiated (either implicitly or explicitly).
6863 /// \param HasNoEffect will be set to true to indicate that the new
6864 /// specialization or instantiation has no effect and should be ignored.
6866 /// \returns true if there was an error that should prevent the introduction of
6867 /// the new declaration into the AST, false otherwise.
6869 Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc,
6870 TemplateSpecializationKind NewTSK,
6871 NamedDecl *PrevDecl,
6872 TemplateSpecializationKind PrevTSK,
6873 SourceLocation PrevPointOfInstantiation,
6874 bool &HasNoEffect) {
6875 HasNoEffect = false;
6878 case TSK_Undeclared:
6879 case TSK_ImplicitInstantiation:
6881 (PrevTSK == TSK_Undeclared || PrevTSK == TSK_ImplicitInstantiation) &&
6882 "previous declaration must be implicit!");
6885 case TSK_ExplicitSpecialization:
6887 case TSK_Undeclared:
6888 case TSK_ExplicitSpecialization:
6889 // Okay, we're just specializing something that is either already
6890 // explicitly specialized or has merely been mentioned without any
6894 case TSK_ImplicitInstantiation:
6895 if (PrevPointOfInstantiation.isInvalid()) {
6896 // The declaration itself has not actually been instantiated, so it is
6897 // still okay to specialize it.
6898 StripImplicitInstantiation(PrevDecl);
6903 case TSK_ExplicitInstantiationDeclaration:
6904 case TSK_ExplicitInstantiationDefinition:
6905 assert((PrevTSK == TSK_ImplicitInstantiation ||
6906 PrevPointOfInstantiation.isValid()) &&
6907 "Explicit instantiation without point of instantiation?");
6909 // C++ [temp.expl.spec]p6:
6910 // If a template, a member template or the member of a class template
6911 // is explicitly specialized then that specialization shall be declared
6912 // before the first use of that specialization that would cause an
6913 // implicit instantiation to take place, in every translation unit in
6914 // which such a use occurs; no diagnostic is required.
6915 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6916 // Is there any previous explicit specialization declaration?
6917 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization)
6921 Diag(NewLoc, diag::err_specialization_after_instantiation)
6923 Diag(PrevPointOfInstantiation, diag::note_instantiation_required_here)
6924 << (PrevTSK != TSK_ImplicitInstantiation);
6929 case TSK_ExplicitInstantiationDeclaration:
6931 case TSK_ExplicitInstantiationDeclaration:
6932 // This explicit instantiation declaration is redundant (that's okay).
6936 case TSK_Undeclared:
6937 case TSK_ImplicitInstantiation:
6938 // We're explicitly instantiating something that may have already been
6939 // implicitly instantiated; that's fine.
6942 case TSK_ExplicitSpecialization:
6943 // C++0x [temp.explicit]p4:
6944 // For a given set of template parameters, if an explicit instantiation
6945 // of a template appears after a declaration of an explicit
6946 // specialization for that template, the explicit instantiation has no
6951 case TSK_ExplicitInstantiationDefinition:
6952 // C++0x [temp.explicit]p10:
6953 // If an entity is the subject of both an explicit instantiation
6954 // declaration and an explicit instantiation definition in the same
6955 // translation unit, the definition shall follow the declaration.
6957 diag::err_explicit_instantiation_declaration_after_definition);
6959 // Explicit instantiations following a specialization have no effect and
6960 // hence no PrevPointOfInstantiation. In that case, walk decl backwards
6961 // until a valid name loc is found.
6962 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
6963 diag::note_explicit_instantiation_definition_here);
6968 case TSK_ExplicitInstantiationDefinition:
6970 case TSK_Undeclared:
6971 case TSK_ImplicitInstantiation:
6972 // We're explicitly instantiating something that may have already been
6973 // implicitly instantiated; that's fine.
6976 case TSK_ExplicitSpecialization:
6977 // C++ DR 259, C++0x [temp.explicit]p4:
6978 // For a given set of template parameters, if an explicit
6979 // instantiation of a template appears after a declaration of
6980 // an explicit specialization for that template, the explicit
6981 // instantiation has no effect.
6982 Diag(NewLoc, diag::warn_explicit_instantiation_after_specialization)
6984 Diag(PrevDecl->getLocation(),
6985 diag::note_previous_template_specialization);
6989 case TSK_ExplicitInstantiationDeclaration:
6990 // We're explicity instantiating a definition for something for which we
6991 // were previously asked to suppress instantiations. That's fine.
6993 // C++0x [temp.explicit]p4:
6994 // For a given set of template parameters, if an explicit instantiation
6995 // of a template appears after a declaration of an explicit
6996 // specialization for that template, the explicit instantiation has no
6998 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6999 // Is there any previous explicit specialization declaration?
7000 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
7008 case TSK_ExplicitInstantiationDefinition:
7009 // C++0x [temp.spec]p5:
7010 // For a given template and a given set of template-arguments,
7011 // - an explicit instantiation definition shall appear at most once
7014 // MSVCCompat: MSVC silently ignores duplicate explicit instantiations.
7015 Diag(NewLoc, (getLangOpts().MSVCCompat)
7016 ? diag::ext_explicit_instantiation_duplicate
7017 : diag::err_explicit_instantiation_duplicate)
7019 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
7020 diag::note_previous_explicit_instantiation);
7026 llvm_unreachable("Missing specialization/instantiation case?");
7029 /// \brief Perform semantic analysis for the given dependent function
7030 /// template specialization.
7032 /// The only possible way to get a dependent function template specialization
7033 /// is with a friend declaration, like so:
7036 /// template \<class T> void foo(T);
7037 /// template \<class T> class A {
7038 /// friend void foo<>(T);
7042 /// There really isn't any useful analysis we can do here, so we
7043 /// just store the information.
7045 Sema::CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD,
7046 const TemplateArgumentListInfo &ExplicitTemplateArgs,
7047 LookupResult &Previous) {
7048 // Remove anything from Previous that isn't a function template in
7049 // the correct context.
7050 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
7051 LookupResult::Filter F = Previous.makeFilter();
7052 while (F.hasNext()) {
7053 NamedDecl *D = F.next()->getUnderlyingDecl();
7054 if (!isa<FunctionTemplateDecl>(D) ||
7055 !FDLookupContext->InEnclosingNamespaceSetOf(
7056 D->getDeclContext()->getRedeclContext()))
7061 // Should this be diagnosed here?
7062 if (Previous.empty()) return true;
7064 FD->setDependentTemplateSpecialization(Context, Previous.asUnresolvedSet(),
7065 ExplicitTemplateArgs);
7069 /// \brief Perform semantic analysis for the given function template
7072 /// This routine performs all of the semantic analysis required for an
7073 /// explicit function template specialization. On successful completion,
7074 /// the function declaration \p FD will become a function template
7077 /// \param FD the function declaration, which will be updated to become a
7078 /// function template specialization.
7080 /// \param ExplicitTemplateArgs the explicitly-provided template arguments,
7081 /// if any. Note that this may be valid info even when 0 arguments are
7082 /// explicitly provided as in, e.g., \c void sort<>(char*, char*);
7083 /// as it anyway contains info on the angle brackets locations.
7085 /// \param Previous the set of declarations that may be specialized by
7086 /// this function specialization.
7087 bool Sema::CheckFunctionTemplateSpecialization(
7088 FunctionDecl *FD, TemplateArgumentListInfo *ExplicitTemplateArgs,
7089 LookupResult &Previous) {
7090 // The set of function template specializations that could match this
7091 // explicit function template specialization.
7092 UnresolvedSet<8> Candidates;
7093 TemplateSpecCandidateSet FailedCandidates(FD->getLocation(),
7094 /*ForTakingAddress=*/false);
7096 llvm::SmallDenseMap<FunctionDecl *, TemplateArgumentListInfo, 8>
7097 ConvertedTemplateArgs;
7099 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
7100 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
7102 NamedDecl *Ovl = (*I)->getUnderlyingDecl();
7103 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Ovl)) {
7104 // Only consider templates found within the same semantic lookup scope as
7106 if (!FDLookupContext->InEnclosingNamespaceSetOf(
7107 Ovl->getDeclContext()->getRedeclContext()))
7110 // When matching a constexpr member function template specialization
7111 // against the primary template, we don't yet know whether the
7112 // specialization has an implicit 'const' (because we don't know whether
7113 // it will be a static member function until we know which template it
7114 // specializes), so adjust it now assuming it specializes this template.
7115 QualType FT = FD->getType();
7116 if (FD->isConstexpr()) {
7117 CXXMethodDecl *OldMD =
7118 dyn_cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl());
7119 if (OldMD && OldMD->isConst()) {
7120 const FunctionProtoType *FPT = FT->castAs<FunctionProtoType>();
7121 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
7122 EPI.TypeQuals |= Qualifiers::Const;
7123 FT = Context.getFunctionType(FPT->getReturnType(),
7124 FPT->getParamTypes(), EPI);
7128 TemplateArgumentListInfo Args;
7129 if (ExplicitTemplateArgs)
7130 Args = *ExplicitTemplateArgs;
7132 // C++ [temp.expl.spec]p11:
7133 // A trailing template-argument can be left unspecified in the
7134 // template-id naming an explicit function template specialization
7135 // provided it can be deduced from the function argument type.
7136 // Perform template argument deduction to determine whether we may be
7137 // specializing this template.
7138 // FIXME: It is somewhat wasteful to build
7139 TemplateDeductionInfo Info(FailedCandidates.getLocation());
7140 FunctionDecl *Specialization = nullptr;
7141 if (TemplateDeductionResult TDK = DeduceTemplateArguments(
7142 cast<FunctionTemplateDecl>(FunTmpl->getFirstDecl()),
7143 ExplicitTemplateArgs ? &Args : nullptr, FT, Specialization,
7145 // Template argument deduction failed; record why it failed, so
7146 // that we can provide nifty diagnostics.
7147 FailedCandidates.addCandidate().set(
7148 I.getPair(), FunTmpl->getTemplatedDecl(),
7149 MakeDeductionFailureInfo(Context, TDK, Info));
7154 // Target attributes are part of the cuda function signature, so
7155 // the deduced template's cuda target must match that of the
7156 // specialization. Given that C++ template deduction does not
7157 // take target attributes into account, we reject candidates
7158 // here that have a different target.
7159 if (LangOpts.CUDA &&
7160 IdentifyCUDATarget(Specialization,
7161 /* IgnoreImplicitHDAttributes = */ true) !=
7162 IdentifyCUDATarget(FD, /* IgnoreImplicitHDAttributes = */ true)) {
7163 FailedCandidates.addCandidate().set(
7164 I.getPair(), FunTmpl->getTemplatedDecl(),
7165 MakeDeductionFailureInfo(Context, TDK_CUDATargetMismatch, Info));
7169 // Record this candidate.
7170 if (ExplicitTemplateArgs)
7171 ConvertedTemplateArgs[Specialization] = std::move(Args);
7172 Candidates.addDecl(Specialization, I.getAccess());
7176 // Find the most specialized function template.
7177 UnresolvedSetIterator Result = getMostSpecialized(
7178 Candidates.begin(), Candidates.end(), FailedCandidates,
7180 PDiag(diag::err_function_template_spec_no_match) << FD->getDeclName(),
7181 PDiag(diag::err_function_template_spec_ambiguous)
7182 << FD->getDeclName() << (ExplicitTemplateArgs != nullptr),
7183 PDiag(diag::note_function_template_spec_matched));
7185 if (Result == Candidates.end())
7188 // Ignore access information; it doesn't figure into redeclaration checking.
7189 FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
7191 // C++ Concepts TS [dcl.spec.concept]p7: A program shall not declare [...]
7192 // an explicit specialization (14.8.3) [...] of a concept definition.
7193 if (Specialization->getPrimaryTemplate()->isConcept()) {
7194 Diag(FD->getLocation(), diag::err_concept_specialized)
7195 << 0 /*function*/ << 1 /*explicitly specialized*/;
7196 Diag(Specialization->getLocation(), diag::note_previous_declaration);
7200 FunctionTemplateSpecializationInfo *SpecInfo
7201 = Specialization->getTemplateSpecializationInfo();
7202 assert(SpecInfo && "Function template specialization info missing?");
7204 // Note: do not overwrite location info if previous template
7205 // specialization kind was explicit.
7206 TemplateSpecializationKind TSK = SpecInfo->getTemplateSpecializationKind();
7207 if (TSK == TSK_Undeclared || TSK == TSK_ImplicitInstantiation) {
7208 Specialization->setLocation(FD->getLocation());
7209 // C++11 [dcl.constexpr]p1: An explicit specialization of a constexpr
7210 // function can differ from the template declaration with respect to
7211 // the constexpr specifier.
7212 Specialization->setConstexpr(FD->isConstexpr());
7215 // FIXME: Check if the prior specialization has a point of instantiation.
7216 // If so, we have run afoul of .
7218 // If this is a friend declaration, then we're not really declaring
7219 // an explicit specialization.
7220 bool isFriend = (FD->getFriendObjectKind() != Decl::FOK_None);
7222 // Check the scope of this explicit specialization.
7224 CheckTemplateSpecializationScope(*this,
7225 Specialization->getPrimaryTemplate(),
7226 Specialization, FD->getLocation(),
7230 // C++ [temp.expl.spec]p6:
7231 // If a template, a member template or the member of a class template is
7232 // explicitly specialized then that specialization shall be declared
7233 // before the first use of that specialization that would cause an implicit
7234 // instantiation to take place, in every translation unit in which such a
7235 // use occurs; no diagnostic is required.
7236 bool HasNoEffect = false;
7238 CheckSpecializationInstantiationRedecl(FD->getLocation(),
7239 TSK_ExplicitSpecialization,
7241 SpecInfo->getTemplateSpecializationKind(),
7242 SpecInfo->getPointOfInstantiation(),
7246 // Mark the prior declaration as an explicit specialization, so that later
7247 // clients know that this is an explicit specialization.
7249 // Since explicit specializations do not inherit '=delete' from their
7250 // primary function template - check if the 'specialization' that was
7251 // implicitly generated (during template argument deduction for partial
7252 // ordering) from the most specialized of all the function templates that
7253 // 'FD' could have been specializing, has a 'deleted' definition. If so,
7254 // first check that it was implicitly generated during template argument
7255 // deduction by making sure it wasn't referenced, and then reset the deleted
7256 // flag to not-deleted, so that we can inherit that information from 'FD'.
7257 if (Specialization->isDeleted() && !SpecInfo->isExplicitSpecialization() &&
7258 !Specialization->getCanonicalDecl()->isReferenced()) {
7260 Specialization->getCanonicalDecl() == Specialization &&
7261 "This must be the only existing declaration of this specialization");
7262 Specialization->setDeletedAsWritten(false);
7264 SpecInfo->setTemplateSpecializationKind(TSK_ExplicitSpecialization);
7265 MarkUnusedFileScopedDecl(Specialization);
7268 // Turn the given function declaration into a function template
7269 // specialization, with the template arguments from the previous
7271 // Take copies of (semantic and syntactic) template argument lists.
7272 const TemplateArgumentList* TemplArgs = new (Context)
7273 TemplateArgumentList(Specialization->getTemplateSpecializationArgs());
7274 FD->setFunctionTemplateSpecialization(
7275 Specialization->getPrimaryTemplate(), TemplArgs, /*InsertPos=*/nullptr,
7276 SpecInfo->getTemplateSpecializationKind(),
7277 ExplicitTemplateArgs ? &ConvertedTemplateArgs[Specialization] : nullptr);
7279 // A function template specialization inherits the target attributes
7280 // of its template. (We require the attributes explicitly in the
7281 // code to match, but a template may have implicit attributes by
7282 // virtue e.g. of being constexpr, and it passes these implicit
7283 // attributes on to its specializations.)
7285 inheritCUDATargetAttrs(FD, *Specialization->getPrimaryTemplate());
7287 // The "previous declaration" for this function template specialization is
7288 // the prior function template specialization.
7290 Previous.addDecl(Specialization);
7294 /// \brief Perform semantic analysis for the given non-template member
7297 /// This routine performs all of the semantic analysis required for an
7298 /// explicit member function specialization. On successful completion,
7299 /// the function declaration \p FD will become a member function
7302 /// \param Member the member declaration, which will be updated to become a
7305 /// \param Previous the set of declarations, one of which may be specialized
7306 /// by this function specialization; the set will be modified to contain the
7307 /// redeclared member.
7309 Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
7310 assert(!isa<TemplateDecl>(Member) && "Only for non-template members");
7312 // Try to find the member we are instantiating.
7313 NamedDecl *FoundInstantiation = nullptr;
7314 NamedDecl *Instantiation = nullptr;
7315 NamedDecl *InstantiatedFrom = nullptr;
7316 MemberSpecializationInfo *MSInfo = nullptr;
7318 if (Previous.empty()) {
7319 // Nowhere to look anyway.
7320 } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Member)) {
7321 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
7323 NamedDecl *D = (*I)->getUnderlyingDecl();
7324 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
7325 QualType Adjusted = Function->getType();
7326 if (!hasExplicitCallingConv(Adjusted))
7327 Adjusted = adjustCCAndNoReturn(Adjusted, Method->getType());
7328 if (Context.hasSameType(Adjusted, Method->getType())) {
7329 FoundInstantiation = *I;
7330 Instantiation = Method;
7331 InstantiatedFrom = Method->getInstantiatedFromMemberFunction();
7332 MSInfo = Method->getMemberSpecializationInfo();
7337 } else if (isa<VarDecl>(Member)) {
7339 if (Previous.isSingleResult() &&
7340 (PrevVar = dyn_cast<VarDecl>(Previous.getFoundDecl())))
7341 if (PrevVar->isStaticDataMember()) {
7342 FoundInstantiation = Previous.getRepresentativeDecl();
7343 Instantiation = PrevVar;
7344 InstantiatedFrom = PrevVar->getInstantiatedFromStaticDataMember();
7345 MSInfo = PrevVar->getMemberSpecializationInfo();
7347 } else if (isa<RecordDecl>(Member)) {
7348 CXXRecordDecl *PrevRecord;
7349 if (Previous.isSingleResult() &&
7350 (PrevRecord = dyn_cast<CXXRecordDecl>(Previous.getFoundDecl()))) {
7351 FoundInstantiation = Previous.getRepresentativeDecl();
7352 Instantiation = PrevRecord;
7353 InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass();
7354 MSInfo = PrevRecord->getMemberSpecializationInfo();
7356 } else if (isa<EnumDecl>(Member)) {
7358 if (Previous.isSingleResult() &&
7359 (PrevEnum = dyn_cast<EnumDecl>(Previous.getFoundDecl()))) {
7360 FoundInstantiation = Previous.getRepresentativeDecl();
7361 Instantiation = PrevEnum;
7362 InstantiatedFrom = PrevEnum->getInstantiatedFromMemberEnum();
7363 MSInfo = PrevEnum->getMemberSpecializationInfo();
7367 if (!Instantiation) {
7368 // There is no previous declaration that matches. Since member
7369 // specializations are always out-of-line, the caller will complain about
7370 // this mismatch later.
7374 // If this is a friend, just bail out here before we start turning
7375 // things into explicit specializations.
7376 if (Member->getFriendObjectKind() != Decl::FOK_None) {
7377 // Preserve instantiation information.
7378 if (InstantiatedFrom && isa<CXXMethodDecl>(Member)) {
7379 cast<CXXMethodDecl>(Member)->setInstantiationOfMemberFunction(
7380 cast<CXXMethodDecl>(InstantiatedFrom),
7381 cast<CXXMethodDecl>(Instantiation)->getTemplateSpecializationKind());
7382 } else if (InstantiatedFrom && isa<CXXRecordDecl>(Member)) {
7383 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
7384 cast<CXXRecordDecl>(InstantiatedFrom),
7385 cast<CXXRecordDecl>(Instantiation)->getTemplateSpecializationKind());
7389 Previous.addDecl(FoundInstantiation);
7393 // Make sure that this is a specialization of a member.
7394 if (!InstantiatedFrom) {
7395 Diag(Member->getLocation(), diag::err_spec_member_not_instantiated)
7397 Diag(Instantiation->getLocation(), diag::note_specialized_decl);
7401 // C++ [temp.expl.spec]p6:
7402 // If a template, a member template or the member of a class template is
7403 // explicitly specialized then that specialization shall be declared
7404 // before the first use of that specialization that would cause an implicit
7405 // instantiation to take place, in every translation unit in which such a
7406 // use occurs; no diagnostic is required.
7407 assert(MSInfo && "Member specialization info missing?");
7409 bool HasNoEffect = false;
7410 if (CheckSpecializationInstantiationRedecl(Member->getLocation(),
7411 TSK_ExplicitSpecialization,
7413 MSInfo->getTemplateSpecializationKind(),
7414 MSInfo->getPointOfInstantiation(),
7418 // Check the scope of this explicit specialization.
7419 if (CheckTemplateSpecializationScope(*this,
7421 Instantiation, Member->getLocation(),
7425 // Note that this is an explicit instantiation of a member.
7426 // the original declaration to note that it is an explicit specialization
7427 // (if it was previously an implicit instantiation). This latter step
7428 // makes bookkeeping easier.
7429 if (isa<FunctionDecl>(Member)) {
7430 FunctionDecl *InstantiationFunction = cast<FunctionDecl>(Instantiation);
7431 if (InstantiationFunction->getTemplateSpecializationKind() ==
7432 TSK_ImplicitInstantiation) {
7433 InstantiationFunction->setTemplateSpecializationKind(
7434 TSK_ExplicitSpecialization);
7435 InstantiationFunction->setLocation(Member->getLocation());
7436 // Explicit specializations of member functions of class templates do not
7437 // inherit '=delete' from the member function they are specializing.
7438 if (InstantiationFunction->isDeleted()) {
7439 assert(InstantiationFunction->getCanonicalDecl() ==
7440 InstantiationFunction);
7441 InstantiationFunction->setDeletedAsWritten(false);
7445 cast<FunctionDecl>(Member)->setInstantiationOfMemberFunction(
7446 cast<CXXMethodDecl>(InstantiatedFrom),
7447 TSK_ExplicitSpecialization);
7448 MarkUnusedFileScopedDecl(InstantiationFunction);
7449 } else if (isa<VarDecl>(Member)) {
7450 VarDecl *InstantiationVar = cast<VarDecl>(Instantiation);
7451 if (InstantiationVar->getTemplateSpecializationKind() ==
7452 TSK_ImplicitInstantiation) {
7453 InstantiationVar->setTemplateSpecializationKind(
7454 TSK_ExplicitSpecialization);
7455 InstantiationVar->setLocation(Member->getLocation());
7458 cast<VarDecl>(Member)->setInstantiationOfStaticDataMember(
7459 cast<VarDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
7460 MarkUnusedFileScopedDecl(InstantiationVar);
7461 } else if (isa<CXXRecordDecl>(Member)) {
7462 CXXRecordDecl *InstantiationClass = cast<CXXRecordDecl>(Instantiation);
7463 if (InstantiationClass->getTemplateSpecializationKind() ==
7464 TSK_ImplicitInstantiation) {
7465 InstantiationClass->setTemplateSpecializationKind(
7466 TSK_ExplicitSpecialization);
7467 InstantiationClass->setLocation(Member->getLocation());
7470 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
7471 cast<CXXRecordDecl>(InstantiatedFrom),
7472 TSK_ExplicitSpecialization);
7474 assert(isa<EnumDecl>(Member) && "Only member enums remain");
7475 EnumDecl *InstantiationEnum = cast<EnumDecl>(Instantiation);
7476 if (InstantiationEnum->getTemplateSpecializationKind() ==
7477 TSK_ImplicitInstantiation) {
7478 InstantiationEnum->setTemplateSpecializationKind(
7479 TSK_ExplicitSpecialization);
7480 InstantiationEnum->setLocation(Member->getLocation());
7483 cast<EnumDecl>(Member)->setInstantiationOfMemberEnum(
7484 cast<EnumDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
7487 // Save the caller the trouble of having to figure out which declaration
7488 // this specialization matches.
7490 Previous.addDecl(FoundInstantiation);
7494 /// \brief Check the scope of an explicit instantiation.
7496 /// \returns true if a serious error occurs, false otherwise.
7497 static bool CheckExplicitInstantiationScope(Sema &S, NamedDecl *D,
7498 SourceLocation InstLoc,
7499 bool WasQualifiedName) {
7500 DeclContext *OrigContext= D->getDeclContext()->getEnclosingNamespaceContext();
7501 DeclContext *CurContext = S.CurContext->getRedeclContext();
7503 if (CurContext->isRecord()) {
7504 S.Diag(InstLoc, diag::err_explicit_instantiation_in_class)
7509 // C++11 [temp.explicit]p3:
7510 // An explicit instantiation shall appear in an enclosing namespace of its
7511 // template. If the name declared in the explicit instantiation is an
7512 // unqualified name, the explicit instantiation shall appear in the
7513 // namespace where its template is declared or, if that namespace is inline
7514 // (7.3.1), any namespace from its enclosing namespace set.
7516 // This is DR275, which we do not retroactively apply to C++98/03.
7517 if (WasQualifiedName) {
7518 if (CurContext->Encloses(OrigContext))
7521 if (CurContext->InEnclosingNamespaceSetOf(OrigContext))
7525 if (NamespaceDecl *NS = dyn_cast<NamespaceDecl>(OrigContext)) {
7526 if (WasQualifiedName)
7528 S.getLangOpts().CPlusPlus11?
7529 diag::err_explicit_instantiation_out_of_scope :
7530 diag::warn_explicit_instantiation_out_of_scope_0x)
7534 S.getLangOpts().CPlusPlus11?
7535 diag::err_explicit_instantiation_unqualified_wrong_namespace :
7536 diag::warn_explicit_instantiation_unqualified_wrong_namespace_0x)
7540 S.getLangOpts().CPlusPlus11?
7541 diag::err_explicit_instantiation_must_be_global :
7542 diag::warn_explicit_instantiation_must_be_global_0x)
7544 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here);
7548 /// \brief Determine whether the given scope specifier has a template-id in it.
7549 static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec &SS) {
7553 // C++11 [temp.explicit]p3:
7554 // If the explicit instantiation is for a member function, a member class
7555 // or a static data member of a class template specialization, the name of
7556 // the class template specialization in the qualified-id for the member
7557 // name shall be a simple-template-id.
7559 // C++98 has the same restriction, just worded differently.
7560 for (NestedNameSpecifier *NNS = SS.getScopeRep(); NNS;
7561 NNS = NNS->getPrefix())
7562 if (const Type *T = NNS->getAsType())
7563 if (isa<TemplateSpecializationType>(T))
7569 /// Make a dllexport or dllimport attr on a class template specialization take
7571 static void dllExportImportClassTemplateSpecialization(
7572 Sema &S, ClassTemplateSpecializationDecl *Def) {
7573 auto *A = cast_or_null<InheritableAttr>(getDLLAttr(Def));
7574 assert(A && "dllExportImportClassTemplateSpecialization called "
7575 "on Def without dllexport or dllimport");
7577 // We reject explicit instantiations in class scope, so there should
7578 // never be any delayed exported classes to worry about.
7579 assert(S.DelayedDllExportClasses.empty() &&
7580 "delayed exports present at explicit instantiation");
7581 S.checkClassLevelDLLAttribute(Def);
7583 // Propagate attribute to base class templates.
7584 for (auto &B : Def->bases()) {
7585 if (auto *BT = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
7586 B.getType()->getAsCXXRecordDecl()))
7587 S.propagateDLLAttrToBaseClassTemplate(Def, A, BT, B.getLocStart());
7590 S.referenceDLLExportedClassMethods();
7593 // Explicit instantiation of a class template specialization
7595 Sema::ActOnExplicitInstantiation(Scope *S,
7596 SourceLocation ExternLoc,
7597 SourceLocation TemplateLoc,
7599 SourceLocation KWLoc,
7600 const CXXScopeSpec &SS,
7601 TemplateTy TemplateD,
7602 SourceLocation TemplateNameLoc,
7603 SourceLocation LAngleLoc,
7604 ASTTemplateArgsPtr TemplateArgsIn,
7605 SourceLocation RAngleLoc,
7606 AttributeList *Attr) {
7607 // Find the class template we're specializing
7608 TemplateName Name = TemplateD.get();
7609 TemplateDecl *TD = Name.getAsTemplateDecl();
7610 // Check that the specialization uses the same tag kind as the
7611 // original template.
7612 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
7613 assert(Kind != TTK_Enum &&
7614 "Invalid enum tag in class template explicit instantiation!");
7616 ClassTemplateDecl *ClassTemplate = dyn_cast<ClassTemplateDecl>(TD);
7618 if (!ClassTemplate) {
7619 NonTagKind NTK = getNonTagTypeDeclKind(TD, Kind);
7620 Diag(TemplateNameLoc, diag::err_tag_reference_non_tag) << TD << NTK << Kind;
7621 Diag(TD->getLocation(), diag::note_previous_use);
7625 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
7626 Kind, /*isDefinition*/false, KWLoc,
7627 ClassTemplate->getIdentifier())) {
7628 Diag(KWLoc, diag::err_use_with_wrong_tag)
7630 << FixItHint::CreateReplacement(KWLoc,
7631 ClassTemplate->getTemplatedDecl()->getKindName());
7632 Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
7633 diag::note_previous_use);
7634 Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
7637 // C++0x [temp.explicit]p2:
7638 // There are two forms of explicit instantiation: an explicit instantiation
7639 // definition and an explicit instantiation declaration. An explicit
7640 // instantiation declaration begins with the extern keyword. [...]
7641 TemplateSpecializationKind TSK = ExternLoc.isInvalid()
7642 ? TSK_ExplicitInstantiationDefinition
7643 : TSK_ExplicitInstantiationDeclaration;
7645 if (TSK == TSK_ExplicitInstantiationDeclaration) {
7646 // Check for dllexport class template instantiation declarations.
7647 for (AttributeList *A = Attr; A; A = A->getNext()) {
7648 if (A->getKind() == AttributeList::AT_DLLExport) {
7650 diag::warn_attribute_dllexport_explicit_instantiation_decl);
7651 Diag(A->getLoc(), diag::note_attribute);
7656 if (auto *A = ClassTemplate->getTemplatedDecl()->getAttr<DLLExportAttr>()) {
7658 diag::warn_attribute_dllexport_explicit_instantiation_decl);
7659 Diag(A->getLocation(), diag::note_attribute);
7663 // In MSVC mode, dllimported explicit instantiation definitions are treated as
7664 // instantiation declarations for most purposes.
7665 bool DLLImportExplicitInstantiationDef = false;
7666 if (TSK == TSK_ExplicitInstantiationDefinition &&
7667 Context.getTargetInfo().getCXXABI().isMicrosoft()) {
7668 // Check for dllimport class template instantiation definitions.
7670 ClassTemplate->getTemplatedDecl()->getAttr<DLLImportAttr>();
7671 for (AttributeList *A = Attr; A; A = A->getNext()) {
7672 if (A->getKind() == AttributeList::AT_DLLImport)
7674 if (A->getKind() == AttributeList::AT_DLLExport) {
7675 // dllexport trumps dllimport here.
7681 TSK = TSK_ExplicitInstantiationDeclaration;
7682 DLLImportExplicitInstantiationDef = true;
7686 // Translate the parser's template argument list in our AST format.
7687 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
7688 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
7690 // Check that the template argument list is well-formed for this
7692 SmallVector<TemplateArgument, 4> Converted;
7693 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
7694 TemplateArgs, false, Converted))
7697 // Find the class template specialization declaration that
7698 // corresponds to these arguments.
7699 void *InsertPos = nullptr;
7700 ClassTemplateSpecializationDecl *PrevDecl
7701 = ClassTemplate->findSpecialization(Converted, InsertPos);
7703 TemplateSpecializationKind PrevDecl_TSK
7704 = PrevDecl ? PrevDecl->getTemplateSpecializationKind() : TSK_Undeclared;
7706 // C++0x [temp.explicit]p2:
7707 // [...] An explicit instantiation shall appear in an enclosing
7708 // namespace of its template. [...]
7710 // This is C++ DR 275.
7711 if (CheckExplicitInstantiationScope(*this, ClassTemplate, TemplateNameLoc,
7715 ClassTemplateSpecializationDecl *Specialization = nullptr;
7717 bool HasNoEffect = false;
7719 if (CheckSpecializationInstantiationRedecl(TemplateNameLoc, TSK,
7720 PrevDecl, PrevDecl_TSK,
7721 PrevDecl->getPointOfInstantiation(),
7725 // Even though HasNoEffect == true means that this explicit instantiation
7726 // has no effect on semantics, we go on to put its syntax in the AST.
7728 if (PrevDecl_TSK == TSK_ImplicitInstantiation ||
7729 PrevDecl_TSK == TSK_Undeclared) {
7730 // Since the only prior class template specialization with these
7731 // arguments was referenced but not declared, reuse that
7732 // declaration node as our own, updating the source location
7733 // for the template name to reflect our new declaration.
7734 // (Other source locations will be updated later.)
7735 Specialization = PrevDecl;
7736 Specialization->setLocation(TemplateNameLoc);
7740 if (PrevDecl_TSK == TSK_ExplicitInstantiationDeclaration &&
7741 DLLImportExplicitInstantiationDef) {
7742 // The new specialization might add a dllimport attribute.
7743 HasNoEffect = false;
7747 if (!Specialization) {
7748 // Create a new class template specialization declaration node for
7749 // this explicit specialization.
7751 = ClassTemplateSpecializationDecl::Create(Context, Kind,
7752 ClassTemplate->getDeclContext(),
7753 KWLoc, TemplateNameLoc,
7757 SetNestedNameSpecifier(Specialization, SS);
7759 if (!HasNoEffect && !PrevDecl) {
7760 // Insert the new specialization.
7761 ClassTemplate->AddSpecialization(Specialization, InsertPos);
7765 // Build the fully-sugared type for this explicit instantiation as
7766 // the user wrote in the explicit instantiation itself. This means
7767 // that we'll pretty-print the type retrieved from the
7768 // specialization's declaration the way that the user actually wrote
7769 // the explicit instantiation, rather than formatting the name based
7770 // on the "canonical" representation used to store the template
7771 // arguments in the specialization.
7772 TypeSourceInfo *WrittenTy
7773 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
7775 Context.getTypeDeclType(Specialization));
7776 Specialization->setTypeAsWritten(WrittenTy);
7778 // Set source locations for keywords.
7779 Specialization->setExternLoc(ExternLoc);
7780 Specialization->setTemplateKeywordLoc(TemplateLoc);
7781 Specialization->setBraceRange(SourceRange());
7784 ProcessDeclAttributeList(S, Specialization, Attr);
7786 // Add the explicit instantiation into its lexical context. However,
7787 // since explicit instantiations are never found by name lookup, we
7788 // just put it into the declaration context directly.
7789 Specialization->setLexicalDeclContext(CurContext);
7790 CurContext->addDecl(Specialization);
7792 // Syntax is now OK, so return if it has no other effect on semantics.
7794 // Set the template specialization kind.
7795 Specialization->setTemplateSpecializationKind(TSK);
7796 return Specialization;
7799 // C++ [temp.explicit]p3:
7800 // A definition of a class template or class member template
7801 // shall be in scope at the point of the explicit instantiation of
7802 // the class template or class member template.
7804 // This check comes when we actually try to perform the
7806 ClassTemplateSpecializationDecl *Def
7807 = cast_or_null<ClassTemplateSpecializationDecl>(
7808 Specialization->getDefinition());
7810 InstantiateClassTemplateSpecialization(TemplateNameLoc, Specialization, TSK);
7811 else if (TSK == TSK_ExplicitInstantiationDefinition) {
7812 MarkVTableUsed(TemplateNameLoc, Specialization, true);
7813 Specialization->setPointOfInstantiation(Def->getPointOfInstantiation());
7816 // Instantiate the members of this class template specialization.
7817 Def = cast_or_null<ClassTemplateSpecializationDecl>(
7818 Specialization->getDefinition());
7820 TemplateSpecializationKind Old_TSK = Def->getTemplateSpecializationKind();
7821 // Fix a TSK_ExplicitInstantiationDeclaration followed by a
7822 // TSK_ExplicitInstantiationDefinition
7823 if (Old_TSK == TSK_ExplicitInstantiationDeclaration &&
7824 (TSK == TSK_ExplicitInstantiationDefinition ||
7825 DLLImportExplicitInstantiationDef)) {
7826 // FIXME: Need to notify the ASTMutationListener that we did this.
7827 Def->setTemplateSpecializationKind(TSK);
7829 if (!getDLLAttr(Def) && getDLLAttr(Specialization) &&
7830 (Context.getTargetInfo().getCXXABI().isMicrosoft() ||
7831 Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment())) {
7832 // In the MS ABI, an explicit instantiation definition can add a dll
7833 // attribute to a template with a previous instantiation declaration.
7834 // MinGW doesn't allow this.
7835 auto *A = cast<InheritableAttr>(
7836 getDLLAttr(Specialization)->clone(getASTContext()));
7837 A->setInherited(true);
7839 dllExportImportClassTemplateSpecialization(*this, Def);
7843 // Fix a TSK_ImplicitInstantiation followed by a
7844 // TSK_ExplicitInstantiationDefinition
7845 if (Old_TSK == TSK_ImplicitInstantiation &&
7846 Specialization->hasAttr<DLLExportAttr>() &&
7847 (Context.getTargetInfo().getCXXABI().isMicrosoft() ||
7848 Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment())) {
7849 // In the MS ABI, an explicit instantiation definition can add a dll
7850 // attribute to a template with a previous implicit instantiation.
7851 // MinGW doesn't allow this. We limit clang to only adding dllexport, to
7852 // avoid potentially strange codegen behavior. For example, if we extend
7853 // this conditional to dllimport, and we have a source file calling a
7854 // method on an implicitly instantiated template class instance and then
7855 // declaring a dllimport explicit instantiation definition for the same
7856 // template class, the codegen for the method call will not respect the
7857 // dllimport, while it will with cl. The Def will already have the DLL
7858 // attribute, since the Def and Specialization will be the same in the
7859 // case of Old_TSK == TSK_ImplicitInstantiation, and we already added the
7860 // attribute to the Specialization; we just need to make it take effect.
7861 assert(Def == Specialization &&
7862 "Def and Specialization should match for implicit instantiation");
7863 dllExportImportClassTemplateSpecialization(*this, Def);
7866 // Set the template specialization kind. Make sure it is set before
7867 // instantiating the members which will trigger ASTConsumer callbacks.
7868 Specialization->setTemplateSpecializationKind(TSK);
7869 InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK);
7872 // Set the template specialization kind.
7873 Specialization->setTemplateSpecializationKind(TSK);
7876 return Specialization;
7879 // Explicit instantiation of a member class of a class template.
7881 Sema::ActOnExplicitInstantiation(Scope *S,
7882 SourceLocation ExternLoc,
7883 SourceLocation TemplateLoc,
7885 SourceLocation KWLoc,
7887 IdentifierInfo *Name,
7888 SourceLocation NameLoc,
7889 AttributeList *Attr) {
7892 bool IsDependent = false;
7893 Decl *TagD = ActOnTag(S, TagSpec, Sema::TUK_Reference,
7894 KWLoc, SS, Name, NameLoc, Attr, AS_none,
7895 /*ModulePrivateLoc=*/SourceLocation(),
7896 MultiTemplateParamsArg(), Owned, IsDependent,
7897 SourceLocation(), false, TypeResult(),
7898 /*IsTypeSpecifier*/false);
7899 assert(!IsDependent && "explicit instantiation of dependent name not yet handled");
7904 TagDecl *Tag = cast<TagDecl>(TagD);
7905 assert(!Tag->isEnum() && "shouldn't see enumerations here");
7907 if (Tag->isInvalidDecl())
7910 CXXRecordDecl *Record = cast<CXXRecordDecl>(Tag);
7911 CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass();
7913 Diag(TemplateLoc, diag::err_explicit_instantiation_nontemplate_type)
7914 << Context.getTypeDeclType(Record);
7915 Diag(Record->getLocation(), diag::note_nontemplate_decl_here);
7919 // C++0x [temp.explicit]p2:
7920 // If the explicit instantiation is for a class or member class, the
7921 // elaborated-type-specifier in the declaration shall include a
7922 // simple-template-id.
7924 // C++98 has the same restriction, just worded differently.
7925 if (!ScopeSpecifierHasTemplateId(SS))
7926 Diag(TemplateLoc, diag::ext_explicit_instantiation_without_qualified_id)
7927 << Record << SS.getRange();
7929 // C++0x [temp.explicit]p2:
7930 // There are two forms of explicit instantiation: an explicit instantiation
7931 // definition and an explicit instantiation declaration. An explicit
7932 // instantiation declaration begins with the extern keyword. [...]
7933 TemplateSpecializationKind TSK
7934 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
7935 : TSK_ExplicitInstantiationDeclaration;
7937 // C++0x [temp.explicit]p2:
7938 // [...] An explicit instantiation shall appear in an enclosing
7939 // namespace of its template. [...]
7941 // This is C++ DR 275.
7942 CheckExplicitInstantiationScope(*this, Record, NameLoc, true);
7944 // Verify that it is okay to explicitly instantiate here.
7945 CXXRecordDecl *PrevDecl
7946 = cast_or_null<CXXRecordDecl>(Record->getPreviousDecl());
7947 if (!PrevDecl && Record->getDefinition())
7950 MemberSpecializationInfo *MSInfo = PrevDecl->getMemberSpecializationInfo();
7951 bool HasNoEffect = false;
7952 assert(MSInfo && "No member specialization information?");
7953 if (CheckSpecializationInstantiationRedecl(TemplateLoc, TSK,
7955 MSInfo->getTemplateSpecializationKind(),
7956 MSInfo->getPointOfInstantiation(),
7963 CXXRecordDecl *RecordDef
7964 = cast_or_null<CXXRecordDecl>(Record->getDefinition());
7966 // C++ [temp.explicit]p3:
7967 // A definition of a member class of a class template shall be in scope
7968 // at the point of an explicit instantiation of the member class.
7970 = cast_or_null<CXXRecordDecl>(Pattern->getDefinition());
7972 Diag(TemplateLoc, diag::err_explicit_instantiation_undefined_member)
7973 << 0 << Record->getDeclName() << Record->getDeclContext();
7974 Diag(Pattern->getLocation(), diag::note_forward_declaration)
7978 if (InstantiateClass(NameLoc, Record, Def,
7979 getTemplateInstantiationArgs(Record),
7983 RecordDef = cast_or_null<CXXRecordDecl>(Record->getDefinition());
7989 // Instantiate all of the members of the class.
7990 InstantiateClassMembers(NameLoc, RecordDef,
7991 getTemplateInstantiationArgs(Record), TSK);
7993 if (TSK == TSK_ExplicitInstantiationDefinition)
7994 MarkVTableUsed(NameLoc, RecordDef, true);
7996 // FIXME: We don't have any representation for explicit instantiations of
7997 // member classes. Such a representation is not needed for compilation, but it
7998 // should be available for clients that want to see all of the declarations in
8003 DeclResult Sema::ActOnExplicitInstantiation(Scope *S,
8004 SourceLocation ExternLoc,
8005 SourceLocation TemplateLoc,
8007 // Explicit instantiations always require a name.
8008 // TODO: check if/when DNInfo should replace Name.
8009 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
8010 DeclarationName Name = NameInfo.getName();
8012 if (!D.isInvalidType())
8013 Diag(D.getDeclSpec().getLocStart(),
8014 diag::err_explicit_instantiation_requires_name)
8015 << D.getDeclSpec().getSourceRange()
8016 << D.getSourceRange();
8021 // The scope passed in may not be a decl scope. Zip up the scope tree until
8022 // we find one that is.
8023 while ((S->getFlags() & Scope::DeclScope) == 0 ||
8024 (S->getFlags() & Scope::TemplateParamScope) != 0)
8027 // Determine the type of the declaration.
8028 TypeSourceInfo *T = GetTypeForDeclarator(D, S);
8029 QualType R = T->getType();
8034 // A storage-class-specifier shall not be specified in [...] an explicit
8035 // instantiation (14.7.2) directive.
8036 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
8037 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_of_typedef)
8040 } else if (D.getDeclSpec().getStorageClassSpec()
8041 != DeclSpec::SCS_unspecified) {
8042 // Complain about then remove the storage class specifier.
8043 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_storage_class)
8044 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
8046 D.getMutableDeclSpec().ClearStorageClassSpecs();
8049 // C++0x [temp.explicit]p1:
8050 // [...] An explicit instantiation of a function template shall not use the
8051 // inline or constexpr specifiers.
8052 // Presumably, this also applies to member functions of class templates as
8054 if (D.getDeclSpec().isInlineSpecified())
8055 Diag(D.getDeclSpec().getInlineSpecLoc(),
8056 getLangOpts().CPlusPlus11 ?
8057 diag::err_explicit_instantiation_inline :
8058 diag::warn_explicit_instantiation_inline_0x)
8059 << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
8060 if (D.getDeclSpec().isConstexprSpecified() && R->isFunctionType())
8061 // FIXME: Add a fix-it to remove the 'constexpr' and add a 'const' if one is
8062 // not already specified.
8063 Diag(D.getDeclSpec().getConstexprSpecLoc(),
8064 diag::err_explicit_instantiation_constexpr);
8066 // C++ Concepts TS [dcl.spec.concept]p1: The concept specifier shall be
8067 // applied only to the definition of a function template or variable template,
8068 // declared in namespace scope.
8069 if (D.getDeclSpec().isConceptSpecified()) {
8070 Diag(D.getDeclSpec().getConceptSpecLoc(),
8071 diag::err_concept_specified_specialization) << 0;
8075 // C++0x [temp.explicit]p2:
8076 // There are two forms of explicit instantiation: an explicit instantiation
8077 // definition and an explicit instantiation declaration. An explicit
8078 // instantiation declaration begins with the extern keyword. [...]
8079 TemplateSpecializationKind TSK
8080 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
8081 : TSK_ExplicitInstantiationDeclaration;
8083 LookupResult Previous(*this, NameInfo, LookupOrdinaryName);
8084 LookupParsedName(Previous, S, &D.getCXXScopeSpec());
8086 if (!R->isFunctionType()) {
8087 // C++ [temp.explicit]p1:
8088 // A [...] static data member of a class template can be explicitly
8089 // instantiated from the member definition associated with its class
8091 // C++1y [temp.explicit]p1:
8092 // A [...] variable [...] template specialization can be explicitly
8093 // instantiated from its template.
8094 if (Previous.isAmbiguous())
8097 VarDecl *Prev = Previous.getAsSingle<VarDecl>();
8098 VarTemplateDecl *PrevTemplate = Previous.getAsSingle<VarTemplateDecl>();
8100 if (!PrevTemplate) {
8101 if (!Prev || !Prev->isStaticDataMember()) {
8102 // We expect to see a data data member here.
8103 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_not_known)
8105 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
8107 Diag((*P)->getLocation(), diag::note_explicit_instantiation_here);
8111 if (!Prev->getInstantiatedFromStaticDataMember()) {
8112 // FIXME: Check for explicit specialization?
8113 Diag(D.getIdentifierLoc(),
8114 diag::err_explicit_instantiation_data_member_not_instantiated)
8116 Diag(Prev->getLocation(), diag::note_explicit_instantiation_here);
8117 // FIXME: Can we provide a note showing where this was declared?
8121 // Explicitly instantiate a variable template.
8123 // C++1y [dcl.spec.auto]p6:
8124 // ... A program that uses auto or decltype(auto) in a context not
8125 // explicitly allowed in this section is ill-formed.
8127 // This includes auto-typed variable template instantiations.
8128 if (R->isUndeducedType()) {
8129 Diag(T->getTypeLoc().getLocStart(),
8130 diag::err_auto_not_allowed_var_inst);
8134 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId) {
8135 // C++1y [temp.explicit]p3:
8136 // If the explicit instantiation is for a variable, the unqualified-id
8137 // in the declaration shall be a template-id.
8138 Diag(D.getIdentifierLoc(),
8139 diag::err_explicit_instantiation_without_template_id)
8141 Diag(PrevTemplate->getLocation(),
8142 diag::note_explicit_instantiation_here);
8146 // C++ Concepts TS [dcl.spec.concept]p7: A program shall not declare an
8147 // explicit instantiation (14.8.2) [...] of a concept definition.
8148 if (PrevTemplate->isConcept()) {
8149 Diag(D.getIdentifierLoc(), diag::err_concept_specialized)
8150 << 1 /*variable*/ << 0 /*explicitly instantiated*/;
8151 Diag(PrevTemplate->getLocation(), diag::note_previous_declaration);
8155 // Translate the parser's template argument list into our AST format.
8156 TemplateArgumentListInfo TemplateArgs =
8157 makeTemplateArgumentListInfo(*this, *D.getName().TemplateId);
8159 DeclResult Res = CheckVarTemplateId(PrevTemplate, TemplateLoc,
8160 D.getIdentifierLoc(), TemplateArgs);
8161 if (Res.isInvalid())
8164 // Ignore access control bits, we don't need them for redeclaration
8166 Prev = cast<VarDecl>(Res.get());
8169 // C++0x [temp.explicit]p2:
8170 // If the explicit instantiation is for a member function, a member class
8171 // or a static data member of a class template specialization, the name of
8172 // the class template specialization in the qualified-id for the member
8173 // name shall be a simple-template-id.
8175 // C++98 has the same restriction, just worded differently.
8177 // This does not apply to variable template specializations, where the
8178 // template-id is in the unqualified-id instead.
8179 if (!ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()) && !PrevTemplate)
8180 Diag(D.getIdentifierLoc(),
8181 diag::ext_explicit_instantiation_without_qualified_id)
8182 << Prev << D.getCXXScopeSpec().getRange();
8184 // Check the scope of this explicit instantiation.
8185 CheckExplicitInstantiationScope(*this, Prev, D.getIdentifierLoc(), true);
8187 // Verify that it is okay to explicitly instantiate here.
8188 TemplateSpecializationKind PrevTSK = Prev->getTemplateSpecializationKind();
8189 SourceLocation POI = Prev->getPointOfInstantiation();
8190 bool HasNoEffect = false;
8191 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, Prev,
8192 PrevTSK, POI, HasNoEffect))
8196 // Instantiate static data member or variable template.
8198 Prev->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
8200 // Merge attributes.
8201 if (AttributeList *Attr = D.getDeclSpec().getAttributes().getList())
8202 ProcessDeclAttributeList(S, Prev, Attr);
8204 if (TSK == TSK_ExplicitInstantiationDefinition)
8205 InstantiateVariableDefinition(D.getIdentifierLoc(), Prev);
8208 // Check the new variable specialization against the parsed input.
8209 if (PrevTemplate && Prev && !Context.hasSameType(Prev->getType(), R)) {
8210 Diag(T->getTypeLoc().getLocStart(),
8211 diag::err_invalid_var_template_spec_type)
8212 << 0 << PrevTemplate << R << Prev->getType();
8213 Diag(PrevTemplate->getLocation(), diag::note_template_declared_here)
8214 << 2 << PrevTemplate->getDeclName();
8218 // FIXME: Create an ExplicitInstantiation node?
8219 return (Decl*) nullptr;
8222 // If the declarator is a template-id, translate the parser's template
8223 // argument list into our AST format.
8224 bool HasExplicitTemplateArgs = false;
8225 TemplateArgumentListInfo TemplateArgs;
8226 if (D.getName().getKind() == UnqualifiedId::IK_TemplateId) {
8227 TemplateArgs = makeTemplateArgumentListInfo(*this, *D.getName().TemplateId);
8228 HasExplicitTemplateArgs = true;
8231 // C++ [temp.explicit]p1:
8232 // A [...] function [...] can be explicitly instantiated from its template.
8233 // A member function [...] of a class template can be explicitly
8234 // instantiated from the member definition associated with its class
8236 UnresolvedSet<8> Matches;
8237 AttributeList *Attr = D.getDeclSpec().getAttributes().getList();
8238 TemplateSpecCandidateSet FailedCandidates(D.getIdentifierLoc());
8239 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
8241 NamedDecl *Prev = *P;
8242 if (!HasExplicitTemplateArgs) {
8243 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Prev)) {
8244 QualType Adjusted = adjustCCAndNoReturn(R, Method->getType(),
8245 /*AdjustExceptionSpec*/true);
8246 if (Context.hasSameUnqualifiedType(Method->getType(), Adjusted)) {
8249 Matches.addDecl(Method, P.getAccess());
8250 if (Method->getTemplateSpecializationKind() == TSK_Undeclared)
8256 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Prev);
8260 TemplateDeductionInfo Info(FailedCandidates.getLocation());
8261 FunctionDecl *Specialization = nullptr;
8262 if (TemplateDeductionResult TDK
8263 = DeduceTemplateArguments(FunTmpl,
8264 (HasExplicitTemplateArgs ? &TemplateArgs
8266 R, Specialization, Info)) {
8267 // Keep track of almost-matches.
8268 FailedCandidates.addCandidate()
8269 .set(P.getPair(), FunTmpl->getTemplatedDecl(),
8270 MakeDeductionFailureInfo(Context, TDK, Info));
8275 // Target attributes are part of the cuda function signature, so
8276 // the cuda target of the instantiated function must match that of its
8277 // template. Given that C++ template deduction does not take
8278 // target attributes into account, we reject candidates here that
8279 // have a different target.
8280 if (LangOpts.CUDA &&
8281 IdentifyCUDATarget(Specialization,
8282 /* IgnoreImplicitHDAttributes = */ true) !=
8283 IdentifyCUDATarget(Attr)) {
8284 FailedCandidates.addCandidate().set(
8285 P.getPair(), FunTmpl->getTemplatedDecl(),
8286 MakeDeductionFailureInfo(Context, TDK_CUDATargetMismatch, Info));
8290 Matches.addDecl(Specialization, P.getAccess());
8293 // Find the most specialized function template specialization.
8294 UnresolvedSetIterator Result = getMostSpecialized(
8295 Matches.begin(), Matches.end(), FailedCandidates,
8296 D.getIdentifierLoc(),
8297 PDiag(diag::err_explicit_instantiation_not_known) << Name,
8298 PDiag(diag::err_explicit_instantiation_ambiguous) << Name,
8299 PDiag(diag::note_explicit_instantiation_candidate));
8301 if (Result == Matches.end())
8304 // Ignore access control bits, we don't need them for redeclaration checking.
8305 FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
8307 // C++11 [except.spec]p4
8308 // In an explicit instantiation an exception-specification may be specified,
8309 // but is not required.
8310 // If an exception-specification is specified in an explicit instantiation
8311 // directive, it shall be compatible with the exception-specifications of
8312 // other declarations of that function.
8313 if (auto *FPT = R->getAs<FunctionProtoType>())
8314 if (FPT->hasExceptionSpec()) {
8316 diag::err_mismatched_exception_spec_explicit_instantiation;
8317 if (getLangOpts().MicrosoftExt)
8318 DiagID = diag::ext_mismatched_exception_spec_explicit_instantiation;
8319 bool Result = CheckEquivalentExceptionSpec(
8320 PDiag(DiagID) << Specialization->getType(),
8321 PDiag(diag::note_explicit_instantiation_here),
8322 Specialization->getType()->getAs<FunctionProtoType>(),
8323 Specialization->getLocation(), FPT, D.getLocStart());
8324 // In Microsoft mode, mismatching exception specifications just cause a
8326 if (!getLangOpts().MicrosoftExt && Result)
8330 if (Specialization->getTemplateSpecializationKind() == TSK_Undeclared) {
8331 Diag(D.getIdentifierLoc(),
8332 diag::err_explicit_instantiation_member_function_not_instantiated)
8334 << (Specialization->getTemplateSpecializationKind() ==
8335 TSK_ExplicitSpecialization);
8336 Diag(Specialization->getLocation(), diag::note_explicit_instantiation_here);
8340 FunctionDecl *PrevDecl = Specialization->getPreviousDecl();
8341 if (!PrevDecl && Specialization->isThisDeclarationADefinition())
8342 PrevDecl = Specialization;
8345 bool HasNoEffect = false;
8346 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK,
8348 PrevDecl->getTemplateSpecializationKind(),
8349 PrevDecl->getPointOfInstantiation(),
8353 // FIXME: We may still want to build some representation of this
8354 // explicit specialization.
8356 return (Decl*) nullptr;
8359 Specialization->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
8361 ProcessDeclAttributeList(S, Specialization, Attr);
8363 if (Specialization->isDefined()) {
8364 // Let the ASTConsumer know that this function has been explicitly
8365 // instantiated now, and its linkage might have changed.
8366 Consumer.HandleTopLevelDecl(DeclGroupRef(Specialization));
8367 } else if (TSK == TSK_ExplicitInstantiationDefinition)
8368 InstantiateFunctionDefinition(D.getIdentifierLoc(), Specialization);
8370 // C++0x [temp.explicit]p2:
8371 // If the explicit instantiation is for a member function, a member class
8372 // or a static data member of a class template specialization, the name of
8373 // the class template specialization in the qualified-id for the member
8374 // name shall be a simple-template-id.
8376 // C++98 has the same restriction, just worded differently.
8377 FunctionTemplateDecl *FunTmpl = Specialization->getPrimaryTemplate();
8378 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId && !FunTmpl &&
8379 D.getCXXScopeSpec().isSet() &&
8380 !ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()))
8381 Diag(D.getIdentifierLoc(),
8382 diag::ext_explicit_instantiation_without_qualified_id)
8383 << Specialization << D.getCXXScopeSpec().getRange();
8385 // C++ Concepts TS [dcl.spec.concept]p7: A program shall not declare an
8386 // explicit instantiation (14.8.2) [...] of a concept definition.
8387 if (FunTmpl && FunTmpl->isConcept() &&
8388 !D.getDeclSpec().isConceptSpecified()) {
8389 Diag(D.getIdentifierLoc(), diag::err_concept_specialized)
8390 << 0 /*function*/ << 0 /*explicitly instantiated*/;
8391 Diag(FunTmpl->getLocation(), diag::note_previous_declaration);
8395 CheckExplicitInstantiationScope(*this,
8396 FunTmpl? (NamedDecl *)FunTmpl
8397 : Specialization->getInstantiatedFromMemberFunction(),
8398 D.getIdentifierLoc(),
8399 D.getCXXScopeSpec().isSet());
8401 // FIXME: Create some kind of ExplicitInstantiationDecl here.
8402 return (Decl*) nullptr;
8406 Sema::ActOnDependentTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
8407 const CXXScopeSpec &SS, IdentifierInfo *Name,
8408 SourceLocation TagLoc, SourceLocation NameLoc) {
8409 // This has to hold, because SS is expected to be defined.
8410 assert(Name && "Expected a name in a dependent tag");
8412 NestedNameSpecifier *NNS = SS.getScopeRep();
8416 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
8418 if (TUK == TUK_Declaration || TUK == TUK_Definition) {
8419 Diag(NameLoc, diag::err_dependent_tag_decl)
8420 << (TUK == TUK_Definition) << Kind << SS.getRange();
8424 // Create the resulting type.
8425 ElaboratedTypeKeyword Kwd = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
8426 QualType Result = Context.getDependentNameType(Kwd, NNS, Name);
8428 // Create type-source location information for this type.
8430 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(Result);
8431 TL.setElaboratedKeywordLoc(TagLoc);
8432 TL.setQualifierLoc(SS.getWithLocInContext(Context));
8433 TL.setNameLoc(NameLoc);
8434 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
8438 Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc,
8439 const CXXScopeSpec &SS, const IdentifierInfo &II,
8440 SourceLocation IdLoc) {
8444 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
8446 getLangOpts().CPlusPlus11 ?
8447 diag::warn_cxx98_compat_typename_outside_of_template :
8448 diag::ext_typename_outside_of_template)
8449 << FixItHint::CreateRemoval(TypenameLoc);
8451 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
8452 QualType T = CheckTypenameType(TypenameLoc.isValid()? ETK_Typename : ETK_None,
8453 TypenameLoc, QualifierLoc, II, IdLoc);
8457 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
8458 if (isa<DependentNameType>(T)) {
8459 DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
8460 TL.setElaboratedKeywordLoc(TypenameLoc);
8461 TL.setQualifierLoc(QualifierLoc);
8462 TL.setNameLoc(IdLoc);
8464 ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>();
8465 TL.setElaboratedKeywordLoc(TypenameLoc);
8466 TL.setQualifierLoc(QualifierLoc);
8467 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
8470 return CreateParsedType(T, TSI);
8474 Sema::ActOnTypenameType(Scope *S,
8475 SourceLocation TypenameLoc,
8476 const CXXScopeSpec &SS,
8477 SourceLocation TemplateKWLoc,
8478 TemplateTy TemplateIn,
8479 SourceLocation TemplateNameLoc,
8480 SourceLocation LAngleLoc,
8481 ASTTemplateArgsPtr TemplateArgsIn,
8482 SourceLocation RAngleLoc) {
8483 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
8485 getLangOpts().CPlusPlus11 ?
8486 diag::warn_cxx98_compat_typename_outside_of_template :
8487 diag::ext_typename_outside_of_template)
8488 << FixItHint::CreateRemoval(TypenameLoc);
8490 // Translate the parser's template argument list in our AST format.
8491 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
8492 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
8494 TemplateName Template = TemplateIn.get();
8495 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
8496 // Construct a dependent template specialization type.
8497 assert(DTN && "dependent template has non-dependent name?");
8498 assert(DTN->getQualifier() == SS.getScopeRep());
8499 QualType T = Context.getDependentTemplateSpecializationType(ETK_Typename,
8500 DTN->getQualifier(),
8501 DTN->getIdentifier(),
8504 // Create source-location information for this type.
8505 TypeLocBuilder Builder;
8506 DependentTemplateSpecializationTypeLoc SpecTL
8507 = Builder.push<DependentTemplateSpecializationTypeLoc>(T);
8508 SpecTL.setElaboratedKeywordLoc(TypenameLoc);
8509 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
8510 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
8511 SpecTL.setTemplateNameLoc(TemplateNameLoc);
8512 SpecTL.setLAngleLoc(LAngleLoc);
8513 SpecTL.setRAngleLoc(RAngleLoc);
8514 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
8515 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
8516 return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
8519 QualType T = CheckTemplateIdType(Template, TemplateNameLoc, TemplateArgs);
8523 // Provide source-location information for the template specialization type.
8524 TypeLocBuilder Builder;
8525 TemplateSpecializationTypeLoc SpecTL
8526 = Builder.push<TemplateSpecializationTypeLoc>(T);
8527 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
8528 SpecTL.setTemplateNameLoc(TemplateNameLoc);
8529 SpecTL.setLAngleLoc(LAngleLoc);
8530 SpecTL.setRAngleLoc(RAngleLoc);
8531 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
8532 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
8534 T = Context.getElaboratedType(ETK_Typename, SS.getScopeRep(), T);
8535 ElaboratedTypeLoc TL = Builder.push<ElaboratedTypeLoc>(T);
8536 TL.setElaboratedKeywordLoc(TypenameLoc);
8537 TL.setQualifierLoc(SS.getWithLocInContext(Context));
8539 TypeSourceInfo *TSI = Builder.getTypeSourceInfo(Context, T);
8540 return CreateParsedType(T, TSI);
8544 /// Determine whether this failed name lookup should be treated as being
8545 /// disabled by a usage of std::enable_if.
8546 static bool isEnableIf(NestedNameSpecifierLoc NNS, const IdentifierInfo &II,
8547 SourceRange &CondRange) {
8548 // We must be looking for a ::type...
8549 if (!II.isStr("type"))
8552 // ... within an explicitly-written template specialization...
8553 if (!NNS || !NNS.getNestedNameSpecifier()->getAsType())
8555 TypeLoc EnableIfTy = NNS.getTypeLoc();
8556 TemplateSpecializationTypeLoc EnableIfTSTLoc =
8557 EnableIfTy.getAs<TemplateSpecializationTypeLoc>();
8558 if (!EnableIfTSTLoc || EnableIfTSTLoc.getNumArgs() == 0)
8560 const TemplateSpecializationType *EnableIfTST =
8561 cast<TemplateSpecializationType>(EnableIfTSTLoc.getTypePtr());
8563 // ... which names a complete class template declaration...
8564 const TemplateDecl *EnableIfDecl =
8565 EnableIfTST->getTemplateName().getAsTemplateDecl();
8566 if (!EnableIfDecl || EnableIfTST->isIncompleteType())
8569 // ... called "enable_if".
8570 const IdentifierInfo *EnableIfII =
8571 EnableIfDecl->getDeclName().getAsIdentifierInfo();
8572 if (!EnableIfII || !EnableIfII->isStr("enable_if"))
8575 // Assume the first template argument is the condition.
8576 CondRange = EnableIfTSTLoc.getArgLoc(0).getSourceRange();
8580 /// \brief Build the type that describes a C++ typename specifier,
8581 /// e.g., "typename T::type".
8583 Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword,
8584 SourceLocation KeywordLoc,
8585 NestedNameSpecifierLoc QualifierLoc,
8586 const IdentifierInfo &II,
8587 SourceLocation IILoc) {
8589 SS.Adopt(QualifierLoc);
8591 DeclContext *Ctx = computeDeclContext(SS);
8593 // If the nested-name-specifier is dependent and couldn't be
8594 // resolved to a type, build a typename type.
8595 assert(QualifierLoc.getNestedNameSpecifier()->isDependent());
8596 return Context.getDependentNameType(Keyword,
8597 QualifierLoc.getNestedNameSpecifier(),
8601 // If the nested-name-specifier refers to the current instantiation,
8602 // the "typename" keyword itself is superfluous. In C++03, the
8603 // program is actually ill-formed. However, DR 382 (in C++0x CD1)
8604 // allows such extraneous "typename" keywords, and we retroactively
8605 // apply this DR to C++03 code with only a warning. In any case we continue.
8607 if (RequireCompleteDeclContext(SS, Ctx))
8610 DeclarationName Name(&II);
8611 LookupResult Result(*this, Name, IILoc, LookupOrdinaryName);
8612 LookupQualifiedName(Result, Ctx, SS);
8613 unsigned DiagID = 0;
8614 Decl *Referenced = nullptr;
8615 switch (Result.getResultKind()) {
8616 case LookupResult::NotFound: {
8617 // If we're looking up 'type' within a template named 'enable_if', produce
8618 // a more specific diagnostic.
8619 SourceRange CondRange;
8620 if (isEnableIf(QualifierLoc, II, CondRange)) {
8621 Diag(CondRange.getBegin(), diag::err_typename_nested_not_found_enable_if)
8622 << Ctx << CondRange;
8626 DiagID = diag::err_typename_nested_not_found;
8630 case LookupResult::FoundUnresolvedValue: {
8631 // We found a using declaration that is a value. Most likely, the using
8632 // declaration itself is meant to have the 'typename' keyword.
8633 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
8635 Diag(IILoc, diag::err_typename_refers_to_using_value_decl)
8636 << Name << Ctx << FullRange;
8637 if (UnresolvedUsingValueDecl *Using
8638 = dyn_cast<UnresolvedUsingValueDecl>(Result.getRepresentativeDecl())){
8639 SourceLocation Loc = Using->getQualifierLoc().getBeginLoc();
8640 Diag(Loc, diag::note_using_value_decl_missing_typename)
8641 << FixItHint::CreateInsertion(Loc, "typename ");
8644 // Fall through to create a dependent typename type, from which we can recover
8647 case LookupResult::NotFoundInCurrentInstantiation:
8648 // Okay, it's a member of an unknown instantiation.
8649 return Context.getDependentNameType(Keyword,
8650 QualifierLoc.getNestedNameSpecifier(),
8653 case LookupResult::Found:
8654 if (TypeDecl *Type = dyn_cast<TypeDecl>(Result.getFoundDecl())) {
8655 // We found a type. Build an ElaboratedType, since the
8656 // typename-specifier was just sugar.
8657 MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
8658 return Context.getElaboratedType(ETK_Typename,
8659 QualifierLoc.getNestedNameSpecifier(),
8660 Context.getTypeDeclType(Type));
8663 DiagID = diag::err_typename_nested_not_type;
8664 Referenced = Result.getFoundDecl();
8667 case LookupResult::FoundOverloaded:
8668 DiagID = diag::err_typename_nested_not_type;
8669 Referenced = *Result.begin();
8672 case LookupResult::Ambiguous:
8676 // If we get here, it's because name lookup did not find a
8677 // type. Emit an appropriate diagnostic and return an error.
8678 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
8680 Diag(IILoc, DiagID) << FullRange << Name << Ctx;
8682 Diag(Referenced->getLocation(), diag::note_typename_refers_here)
8688 // See Sema::RebuildTypeInCurrentInstantiation
8689 class CurrentInstantiationRebuilder
8690 : public TreeTransform<CurrentInstantiationRebuilder> {
8692 DeclarationName Entity;
8695 typedef TreeTransform<CurrentInstantiationRebuilder> inherited;
8697 CurrentInstantiationRebuilder(Sema &SemaRef,
8699 DeclarationName Entity)
8700 : TreeTransform<CurrentInstantiationRebuilder>(SemaRef),
8701 Loc(Loc), Entity(Entity) { }
8703 /// \brief Determine whether the given type \p T has already been
8706 /// For the purposes of type reconstruction, a type has already been
8707 /// transformed if it is NULL or if it is not dependent.
8708 bool AlreadyTransformed(QualType T) {
8709 return T.isNull() || !T->isDependentType();
8712 /// \brief Returns the location of the entity whose type is being
8714 SourceLocation getBaseLocation() { return Loc; }
8716 /// \brief Returns the name of the entity whose type is being rebuilt.
8717 DeclarationName getBaseEntity() { return Entity; }
8719 /// \brief Sets the "base" location and entity when that
8720 /// information is known based on another transformation.
8721 void setBase(SourceLocation Loc, DeclarationName Entity) {
8723 this->Entity = Entity;
8726 ExprResult TransformLambdaExpr(LambdaExpr *E) {
8727 // Lambdas never need to be transformed.
8731 } // end anonymous namespace
8733 /// \brief Rebuilds a type within the context of the current instantiation.
8735 /// The type \p T is part of the type of an out-of-line member definition of
8736 /// a class template (or class template partial specialization) that was parsed
8737 /// and constructed before we entered the scope of the class template (or
8738 /// partial specialization thereof). This routine will rebuild that type now
8739 /// that we have entered the declarator's scope, which may produce different
8740 /// canonical types, e.g.,
8743 /// template<typename T>
8745 /// typedef T* pointer;
8749 /// template<typename T>
8750 /// typename X<T>::pointer X<T>::data() { ... }
8753 /// Here, the type "typename X<T>::pointer" will be created as a DependentNameType,
8754 /// since we do not know that we can look into X<T> when we parsed the type.
8755 /// This function will rebuild the type, performing the lookup of "pointer"
8756 /// in X<T> and returning an ElaboratedType whose canonical type is the same
8757 /// as the canonical type of T*, allowing the return types of the out-of-line
8758 /// definition and the declaration to match.
8759 TypeSourceInfo *Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo *T,
8761 DeclarationName Name) {
8762 if (!T || !T->getType()->isDependentType())
8765 CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name);
8766 return Rebuilder.TransformType(T);
8769 ExprResult Sema::RebuildExprInCurrentInstantiation(Expr *E) {
8770 CurrentInstantiationRebuilder Rebuilder(*this, E->getExprLoc(),
8772 return Rebuilder.TransformExpr(E);
8775 bool Sema::RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS) {
8779 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
8780 CurrentInstantiationRebuilder Rebuilder(*this, SS.getRange().getBegin(),
8782 NestedNameSpecifierLoc Rebuilt
8783 = Rebuilder.TransformNestedNameSpecifierLoc(QualifierLoc);
8791 /// \brief Rebuild the template parameters now that we know we're in a current
8793 bool Sema::RebuildTemplateParamsInCurrentInstantiation(
8794 TemplateParameterList *Params) {
8795 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
8796 Decl *Param = Params->getParam(I);
8798 // There is nothing to rebuild in a type parameter.
8799 if (isa<TemplateTypeParmDecl>(Param))
8802 // Rebuild the template parameter list of a template template parameter.
8803 if (TemplateTemplateParmDecl *TTP
8804 = dyn_cast<TemplateTemplateParmDecl>(Param)) {
8805 if (RebuildTemplateParamsInCurrentInstantiation(
8806 TTP->getTemplateParameters()))
8812 // Rebuild the type of a non-type template parameter.
8813 NonTypeTemplateParmDecl *NTTP = cast<NonTypeTemplateParmDecl>(Param);
8814 TypeSourceInfo *NewTSI
8815 = RebuildTypeInCurrentInstantiation(NTTP->getTypeSourceInfo(),
8816 NTTP->getLocation(),
8817 NTTP->getDeclName());
8821 if (NewTSI != NTTP->getTypeSourceInfo()) {
8822 NTTP->setTypeSourceInfo(NewTSI);
8823 NTTP->setType(NewTSI->getType());
8830 /// \brief Produces a formatted string that describes the binding of
8831 /// template parameters to template arguments.
8833 Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
8834 const TemplateArgumentList &Args) {
8835 return getTemplateArgumentBindingsText(Params, Args.data(), Args.size());
8839 Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
8840 const TemplateArgument *Args,
8842 SmallString<128> Str;
8843 llvm::raw_svector_ostream Out(Str);
8845 if (!Params || Params->size() == 0 || NumArgs == 0)
8846 return std::string();
8848 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
8857 if (const IdentifierInfo *Id = Params->getParam(I)->getIdentifier()) {
8858 Out << Id->getName();
8864 Args[I].print(getPrintingPolicy(), Out);
8871 void Sema::MarkAsLateParsedTemplate(FunctionDecl *FD, Decl *FnD,
8872 CachedTokens &Toks) {
8876 auto LPT = llvm::make_unique<LateParsedTemplate>();
8878 // Take tokens to avoid allocations
8879 LPT->Toks.swap(Toks);
8881 LateParsedTemplateMap.insert(std::make_pair(FD, std::move(LPT)));
8883 FD->setLateTemplateParsed(true);
8886 void Sema::UnmarkAsLateParsedTemplate(FunctionDecl *FD) {
8889 FD->setLateTemplateParsed(false);
8892 bool Sema::IsInsideALocalClassWithinATemplateFunction() {
8893 DeclContext *DC = CurContext;
8896 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(CurContext)) {
8897 const FunctionDecl *FD = RD->isLocalClass();
8898 return (FD && FD->getTemplatedKind() != FunctionDecl::TK_NonTemplate);
8899 } else if (DC->isTranslationUnit() || DC->isNamespace())
8902 DC = DC->getParent();
8908 /// \brief Walk the path from which a declaration was instantiated, and check
8909 /// that every explicit specialization along that path is visible. This enforces
8910 /// C++ [temp.expl.spec]/6:
8912 /// If a template, a member template or a member of a class template is
8913 /// explicitly specialized then that specialization shall be declared before
8914 /// the first use of that specialization that would cause an implicit
8915 /// instantiation to take place, in every translation unit in which such a
8916 /// use occurs; no diagnostic is required.
8918 /// and also C++ [temp.class.spec]/1:
8920 /// A partial specialization shall be declared before the first use of a
8921 /// class template specialization that would make use of the partial
8922 /// specialization as the result of an implicit or explicit instantiation
8923 /// in every translation unit in which such a use occurs; no diagnostic is
8925 class ExplicitSpecializationVisibilityChecker {
8928 llvm::SmallVector<Module *, 8> Modules;
8931 ExplicitSpecializationVisibilityChecker(Sema &S, SourceLocation Loc)
8934 void check(NamedDecl *ND) {
8935 if (auto *FD = dyn_cast<FunctionDecl>(ND))
8936 return checkImpl(FD);
8937 if (auto *RD = dyn_cast<CXXRecordDecl>(ND))
8938 return checkImpl(RD);
8939 if (auto *VD = dyn_cast<VarDecl>(ND))
8940 return checkImpl(VD);
8941 if (auto *ED = dyn_cast<EnumDecl>(ND))
8942 return checkImpl(ED);
8946 void diagnose(NamedDecl *D, bool IsPartialSpec) {
8947 auto Kind = IsPartialSpec ? Sema::MissingImportKind::PartialSpecialization
8948 : Sema::MissingImportKind::ExplicitSpecialization;
8949 const bool Recover = true;
8951 // If we got a custom set of modules (because only a subset of the
8952 // declarations are interesting), use them, otherwise let
8953 // diagnoseMissingImport intelligently pick some.
8954 if (Modules.empty())
8955 S.diagnoseMissingImport(Loc, D, Kind, Recover);
8957 S.diagnoseMissingImport(Loc, D, D->getLocation(), Modules, Kind, Recover);
8960 // Check a specific declaration. There are three problematic cases:
8962 // 1) The declaration is an explicit specialization of a template
8964 // 2) The declaration is an explicit specialization of a member of an
8966 // 3) The declaration is an instantiation of a template, and that template
8967 // is an explicit specialization of a member of a templated class.
8969 // We don't need to go any deeper than that, as the instantiation of the
8970 // surrounding class / etc is not triggered by whatever triggered this
8971 // instantiation, and thus should be checked elsewhere.
8972 template<typename SpecDecl>
8973 void checkImpl(SpecDecl *Spec) {
8974 bool IsHiddenExplicitSpecialization = false;
8975 if (Spec->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) {
8976 IsHiddenExplicitSpecialization =
8977 Spec->getMemberSpecializationInfo()
8978 ? !S.hasVisibleMemberSpecialization(Spec, &Modules)
8979 : !S.hasVisibleDeclaration(Spec);
8981 checkInstantiated(Spec);
8984 if (IsHiddenExplicitSpecialization)
8985 diagnose(Spec->getMostRecentDecl(), false);
8988 void checkInstantiated(FunctionDecl *FD) {
8989 if (auto *TD = FD->getPrimaryTemplate())
8993 void checkInstantiated(CXXRecordDecl *RD) {
8994 auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(RD);
8998 auto From = SD->getSpecializedTemplateOrPartial();
8999 if (auto *TD = From.dyn_cast<ClassTemplateDecl *>())
9002 From.dyn_cast<ClassTemplatePartialSpecializationDecl *>()) {
9003 if (!S.hasVisibleDeclaration(TD))
9009 void checkInstantiated(VarDecl *RD) {
9010 auto *SD = dyn_cast<VarTemplateSpecializationDecl>(RD);
9014 auto From = SD->getSpecializedTemplateOrPartial();
9015 if (auto *TD = From.dyn_cast<VarTemplateDecl *>())
9018 From.dyn_cast<VarTemplatePartialSpecializationDecl *>()) {
9019 if (!S.hasVisibleDeclaration(TD))
9025 void checkInstantiated(EnumDecl *FD) {}
9027 template<typename TemplDecl>
9028 void checkTemplate(TemplDecl *TD) {
9029 if (TD->isMemberSpecialization()) {
9030 if (!S.hasVisibleMemberSpecialization(TD, &Modules))
9031 diagnose(TD->getMostRecentDecl(), false);
9035 } // end anonymous namespace
9037 void Sema::checkSpecializationVisibility(SourceLocation Loc, NamedDecl *Spec) {
9038 if (!getLangOpts().Modules)
9041 ExplicitSpecializationVisibilityChecker(*this, Loc).check(Spec);
9044 /// \brief Check whether a template partial specialization that we've discovered
9045 /// is hidden, and produce suitable diagnostics if so.
9046 void Sema::checkPartialSpecializationVisibility(SourceLocation Loc,
9048 llvm::SmallVector<Module *, 8> Modules;
9049 if (!hasVisibleDeclaration(Spec, &Modules))
9050 diagnoseMissingImport(Loc, Spec, Spec->getLocation(), Modules,
9051 MissingImportKind::PartialSpecialization,