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 // If this is a templated friend in a dependent context we should not put it
1228 // on the redecl chain. In some cases, the templated friend can be the most
1229 // recent declaration tricking the template instantiator to make substitutions
1231 // FIXME: Figure out how to combine with shouldLinkDependentDeclWithPrevious
1232 bool ShouldAddRedecl
1233 = !(TUK == TUK_Friend && CurContext->isDependentContext());
1235 CXXRecordDecl *NewClass =
1236 CXXRecordDecl::Create(Context, Kind, SemanticContext, KWLoc, NameLoc, Name,
1237 PrevClassTemplate && ShouldAddRedecl ?
1238 PrevClassTemplate->getTemplatedDecl() : nullptr,
1239 /*DelayTypeCreation=*/true);
1240 SetNestedNameSpecifier(NewClass, SS);
1241 if (NumOuterTemplateParamLists > 0)
1242 NewClass->setTemplateParameterListsInfo(
1243 Context, llvm::makeArrayRef(OuterTemplateParamLists,
1244 NumOuterTemplateParamLists));
1246 // Add alignment attributes if necessary; these attributes are checked when
1247 // the ASTContext lays out the structure.
1248 if (TUK == TUK_Definition) {
1249 AddAlignmentAttributesForRecord(NewClass);
1250 AddMsStructLayoutForRecord(NewClass);
1253 ClassTemplateDecl *NewTemplate
1254 = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc,
1255 DeclarationName(Name), TemplateParams,
1258 if (ShouldAddRedecl)
1259 NewTemplate->setPreviousDecl(PrevClassTemplate);
1261 NewClass->setDescribedClassTemplate(NewTemplate);
1263 if (ModulePrivateLoc.isValid())
1264 NewTemplate->setModulePrivate();
1266 // Build the type for the class template declaration now.
1267 QualType T = NewTemplate->getInjectedClassNameSpecialization();
1268 T = Context.getInjectedClassNameType(NewClass, T);
1269 assert(T->isDependentType() && "Class template type is not dependent?");
1272 // If we are providing an explicit specialization of a member that is a
1273 // class template, make a note of that.
1274 if (PrevClassTemplate &&
1275 PrevClassTemplate->getInstantiatedFromMemberTemplate())
1276 PrevClassTemplate->setMemberSpecialization();
1278 // Set the access specifier.
1279 if (!Invalid && TUK != TUK_Friend && NewTemplate->getDeclContext()->isRecord())
1280 SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS);
1282 // Set the lexical context of these templates
1283 NewClass->setLexicalDeclContext(CurContext);
1284 NewTemplate->setLexicalDeclContext(CurContext);
1286 if (TUK == TUK_Definition)
1287 NewClass->startDefinition();
1290 ProcessDeclAttributeList(S, NewClass, Attr);
1292 if (PrevClassTemplate)
1293 mergeDeclAttributes(NewClass, PrevClassTemplate->getTemplatedDecl());
1295 AddPushedVisibilityAttribute(NewClass);
1297 if (TUK != TUK_Friend) {
1298 // Per C++ [basic.scope.temp]p2, skip the template parameter scopes.
1300 while ((Outer->getFlags() & Scope::TemplateParamScope) != 0)
1301 Outer = Outer->getParent();
1302 PushOnScopeChains(NewTemplate, Outer);
1304 if (PrevClassTemplate && PrevClassTemplate->getAccess() != AS_none) {
1305 NewTemplate->setAccess(PrevClassTemplate->getAccess());
1306 NewClass->setAccess(PrevClassTemplate->getAccess());
1309 NewTemplate->setObjectOfFriendDecl();
1311 // Friend templates are visible in fairly strange ways.
1312 if (!CurContext->isDependentContext()) {
1313 DeclContext *DC = SemanticContext->getRedeclContext();
1314 DC->makeDeclVisibleInContext(NewTemplate);
1315 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
1316 PushOnScopeChains(NewTemplate, EnclosingScope,
1317 /* AddToContext = */ false);
1320 FriendDecl *Friend = FriendDecl::Create(
1321 Context, CurContext, NewClass->getLocation(), NewTemplate, FriendLoc);
1322 Friend->setAccess(AS_public);
1323 CurContext->addDecl(Friend);
1327 NewTemplate->setInvalidDecl();
1328 NewClass->setInvalidDecl();
1331 ActOnDocumentableDecl(NewTemplate);
1336 /// \brief Diagnose the presence of a default template argument on a
1337 /// template parameter, which is ill-formed in certain contexts.
1339 /// \returns true if the default template argument should be dropped.
1340 static bool DiagnoseDefaultTemplateArgument(Sema &S,
1341 Sema::TemplateParamListContext TPC,
1342 SourceLocation ParamLoc,
1343 SourceRange DefArgRange) {
1345 case Sema::TPC_ClassTemplate:
1346 case Sema::TPC_VarTemplate:
1347 case Sema::TPC_TypeAliasTemplate:
1350 case Sema::TPC_FunctionTemplate:
1351 case Sema::TPC_FriendFunctionTemplateDefinition:
1352 // C++ [temp.param]p9:
1353 // A default template-argument shall not be specified in a
1354 // function template declaration or a function template
1356 // If a friend function template declaration specifies a default
1357 // template-argument, that declaration shall be a definition and shall be
1358 // the only declaration of the function template in the translation unit.
1359 // (C++98/03 doesn't have this wording; see DR226).
1360 S.Diag(ParamLoc, S.getLangOpts().CPlusPlus11 ?
1361 diag::warn_cxx98_compat_template_parameter_default_in_function_template
1362 : diag::ext_template_parameter_default_in_function_template)
1366 case Sema::TPC_ClassTemplateMember:
1367 // C++0x [temp.param]p9:
1368 // A default template-argument shall not be specified in the
1369 // template-parameter-lists of the definition of a member of a
1370 // class template that appears outside of the member's class.
1371 S.Diag(ParamLoc, diag::err_template_parameter_default_template_member)
1375 case Sema::TPC_FriendClassTemplate:
1376 case Sema::TPC_FriendFunctionTemplate:
1377 // C++ [temp.param]p9:
1378 // A default template-argument shall not be specified in a
1379 // friend template declaration.
1380 S.Diag(ParamLoc, diag::err_template_parameter_default_friend_template)
1384 // FIXME: C++0x [temp.param]p9 allows default template-arguments
1385 // for friend function templates if there is only a single
1386 // declaration (and it is a definition). Strange!
1389 llvm_unreachable("Invalid TemplateParamListContext!");
1392 /// \brief Check for unexpanded parameter packs within the template parameters
1393 /// of a template template parameter, recursively.
1394 static bool DiagnoseUnexpandedParameterPacks(Sema &S,
1395 TemplateTemplateParmDecl *TTP) {
1396 // A template template parameter which is a parameter pack is also a pack
1398 if (TTP->isParameterPack())
1401 TemplateParameterList *Params = TTP->getTemplateParameters();
1402 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
1403 NamedDecl *P = Params->getParam(I);
1404 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P)) {
1405 if (!NTTP->isParameterPack() &&
1406 S.DiagnoseUnexpandedParameterPack(NTTP->getLocation(),
1407 NTTP->getTypeSourceInfo(),
1408 Sema::UPPC_NonTypeTemplateParameterType))
1414 if (TemplateTemplateParmDecl *InnerTTP
1415 = dyn_cast<TemplateTemplateParmDecl>(P))
1416 if (DiagnoseUnexpandedParameterPacks(S, InnerTTP))
1423 /// \brief Checks the validity of a template parameter list, possibly
1424 /// considering the template parameter list from a previous
1427 /// If an "old" template parameter list is provided, it must be
1428 /// equivalent (per TemplateParameterListsAreEqual) to the "new"
1429 /// template parameter list.
1431 /// \param NewParams Template parameter list for a new template
1432 /// declaration. This template parameter list will be updated with any
1433 /// default arguments that are carried through from the previous
1434 /// template parameter list.
1436 /// \param OldParams If provided, template parameter list from a
1437 /// previous declaration of the same template. Default template
1438 /// arguments will be merged from the old template parameter list to
1439 /// the new template parameter list.
1441 /// \param TPC Describes the context in which we are checking the given
1442 /// template parameter list.
1444 /// \returns true if an error occurred, false otherwise.
1445 bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
1446 TemplateParameterList *OldParams,
1447 TemplateParamListContext TPC) {
1448 bool Invalid = false;
1450 // C++ [temp.param]p10:
1451 // The set of default template-arguments available for use with a
1452 // template declaration or definition is obtained by merging the
1453 // default arguments from the definition (if in scope) and all
1454 // declarations in scope in the same way default function
1455 // arguments are (8.3.6).
1456 bool SawDefaultArgument = false;
1457 SourceLocation PreviousDefaultArgLoc;
1459 // Dummy initialization to avoid warnings.
1460 TemplateParameterList::iterator OldParam = NewParams->end();
1462 OldParam = OldParams->begin();
1464 bool RemoveDefaultArguments = false;
1465 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
1466 NewParamEnd = NewParams->end();
1467 NewParam != NewParamEnd; ++NewParam) {
1468 // Variables used to diagnose redundant default arguments
1469 bool RedundantDefaultArg = false;
1470 SourceLocation OldDefaultLoc;
1471 SourceLocation NewDefaultLoc;
1473 // Variable used to diagnose missing default arguments
1474 bool MissingDefaultArg = false;
1476 // Variable used to diagnose non-final parameter packs
1477 bool SawParameterPack = false;
1479 if (TemplateTypeParmDecl *NewTypeParm
1480 = dyn_cast<TemplateTypeParmDecl>(*NewParam)) {
1481 // Check the presence of a default argument here.
1482 if (NewTypeParm->hasDefaultArgument() &&
1483 DiagnoseDefaultTemplateArgument(*this, TPC,
1484 NewTypeParm->getLocation(),
1485 NewTypeParm->getDefaultArgumentInfo()->getTypeLoc()
1487 NewTypeParm->removeDefaultArgument();
1489 // Merge default arguments for template type parameters.
1490 TemplateTypeParmDecl *OldTypeParm
1491 = OldParams? cast<TemplateTypeParmDecl>(*OldParam) : nullptr;
1492 if (NewTypeParm->isParameterPack()) {
1493 assert(!NewTypeParm->hasDefaultArgument() &&
1494 "Parameter packs can't have a default argument!");
1495 SawParameterPack = true;
1496 } else if (OldTypeParm && hasVisibleDefaultArgument(OldTypeParm) &&
1497 NewTypeParm->hasDefaultArgument()) {
1498 OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc();
1499 NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc();
1500 SawDefaultArgument = true;
1501 RedundantDefaultArg = true;
1502 PreviousDefaultArgLoc = NewDefaultLoc;
1503 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument()) {
1504 // Merge the default argument from the old declaration to the
1506 NewTypeParm->setInheritedDefaultArgument(Context, OldTypeParm);
1507 PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc();
1508 } else if (NewTypeParm->hasDefaultArgument()) {
1509 SawDefaultArgument = true;
1510 PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc();
1511 } else if (SawDefaultArgument)
1512 MissingDefaultArg = true;
1513 } else if (NonTypeTemplateParmDecl *NewNonTypeParm
1514 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) {
1515 // Check for unexpanded parameter packs.
1516 if (!NewNonTypeParm->isParameterPack() &&
1517 DiagnoseUnexpandedParameterPack(NewNonTypeParm->getLocation(),
1518 NewNonTypeParm->getTypeSourceInfo(),
1519 UPPC_NonTypeTemplateParameterType)) {
1524 // Check the presence of a default argument here.
1525 if (NewNonTypeParm->hasDefaultArgument() &&
1526 DiagnoseDefaultTemplateArgument(*this, TPC,
1527 NewNonTypeParm->getLocation(),
1528 NewNonTypeParm->getDefaultArgument()->getSourceRange())) {
1529 NewNonTypeParm->removeDefaultArgument();
1532 // Merge default arguments for non-type template parameters
1533 NonTypeTemplateParmDecl *OldNonTypeParm
1534 = OldParams? cast<NonTypeTemplateParmDecl>(*OldParam) : nullptr;
1535 if (NewNonTypeParm->isParameterPack()) {
1536 assert(!NewNonTypeParm->hasDefaultArgument() &&
1537 "Parameter packs can't have a default argument!");
1538 if (!NewNonTypeParm->isPackExpansion())
1539 SawParameterPack = true;
1540 } else if (OldNonTypeParm && hasVisibleDefaultArgument(OldNonTypeParm) &&
1541 NewNonTypeParm->hasDefaultArgument()) {
1542 OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc();
1543 NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc();
1544 SawDefaultArgument = true;
1545 RedundantDefaultArg = true;
1546 PreviousDefaultArgLoc = NewDefaultLoc;
1547 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument()) {
1548 // Merge the default argument from the old declaration to the
1550 NewNonTypeParm->setInheritedDefaultArgument(Context, OldNonTypeParm);
1551 PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc();
1552 } else if (NewNonTypeParm->hasDefaultArgument()) {
1553 SawDefaultArgument = true;
1554 PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc();
1555 } else if (SawDefaultArgument)
1556 MissingDefaultArg = true;
1558 TemplateTemplateParmDecl *NewTemplateParm
1559 = cast<TemplateTemplateParmDecl>(*NewParam);
1561 // Check for unexpanded parameter packs, recursively.
1562 if (::DiagnoseUnexpandedParameterPacks(*this, NewTemplateParm)) {
1567 // Check the presence of a default argument here.
1568 if (NewTemplateParm->hasDefaultArgument() &&
1569 DiagnoseDefaultTemplateArgument(*this, TPC,
1570 NewTemplateParm->getLocation(),
1571 NewTemplateParm->getDefaultArgument().getSourceRange()))
1572 NewTemplateParm->removeDefaultArgument();
1574 // Merge default arguments for template template parameters
1575 TemplateTemplateParmDecl *OldTemplateParm
1576 = OldParams? cast<TemplateTemplateParmDecl>(*OldParam) : nullptr;
1577 if (NewTemplateParm->isParameterPack()) {
1578 assert(!NewTemplateParm->hasDefaultArgument() &&
1579 "Parameter packs can't have a default argument!");
1580 if (!NewTemplateParm->isPackExpansion())
1581 SawParameterPack = true;
1582 } else if (OldTemplateParm &&
1583 hasVisibleDefaultArgument(OldTemplateParm) &&
1584 NewTemplateParm->hasDefaultArgument()) {
1585 OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation();
1586 NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation();
1587 SawDefaultArgument = true;
1588 RedundantDefaultArg = true;
1589 PreviousDefaultArgLoc = NewDefaultLoc;
1590 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument()) {
1591 // Merge the default argument from the old declaration to the
1593 NewTemplateParm->setInheritedDefaultArgument(Context, OldTemplateParm);
1594 PreviousDefaultArgLoc
1595 = OldTemplateParm->getDefaultArgument().getLocation();
1596 } else if (NewTemplateParm->hasDefaultArgument()) {
1597 SawDefaultArgument = true;
1598 PreviousDefaultArgLoc
1599 = NewTemplateParm->getDefaultArgument().getLocation();
1600 } else if (SawDefaultArgument)
1601 MissingDefaultArg = true;
1604 // C++11 [temp.param]p11:
1605 // If a template parameter of a primary class template or alias template
1606 // is a template parameter pack, it shall be the last template parameter.
1607 if (SawParameterPack && (NewParam + 1) != NewParamEnd &&
1608 (TPC == TPC_ClassTemplate || TPC == TPC_VarTemplate ||
1609 TPC == TPC_TypeAliasTemplate)) {
1610 Diag((*NewParam)->getLocation(),
1611 diag::err_template_param_pack_must_be_last_template_parameter);
1615 if (RedundantDefaultArg) {
1616 // C++ [temp.param]p12:
1617 // A template-parameter shall not be given default arguments
1618 // by two different declarations in the same scope.
1619 Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition);
1620 Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg);
1622 } else if (MissingDefaultArg && TPC != TPC_FunctionTemplate) {
1623 // C++ [temp.param]p11:
1624 // If a template-parameter of a class template has a default
1625 // template-argument, each subsequent template-parameter shall either
1626 // have a default template-argument supplied or be a template parameter
1628 Diag((*NewParam)->getLocation(),
1629 diag::err_template_param_default_arg_missing);
1630 Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg);
1632 RemoveDefaultArguments = true;
1635 // If we have an old template parameter list that we're merging
1636 // in, move on to the next parameter.
1641 // We were missing some default arguments at the end of the list, so remove
1642 // all of the default arguments.
1643 if (RemoveDefaultArguments) {
1644 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
1645 NewParamEnd = NewParams->end();
1646 NewParam != NewParamEnd; ++NewParam) {
1647 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*NewParam))
1648 TTP->removeDefaultArgument();
1649 else if (NonTypeTemplateParmDecl *NTTP
1650 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam))
1651 NTTP->removeDefaultArgument();
1653 cast<TemplateTemplateParmDecl>(*NewParam)->removeDefaultArgument();
1662 /// A class which looks for a use of a certain level of template
1664 struct DependencyChecker : RecursiveASTVisitor<DependencyChecker> {
1665 typedef RecursiveASTVisitor<DependencyChecker> super;
1668 bool FindLessThanDepth;
1670 // Whether we're looking for a use of a template parameter that makes the
1671 // overall construct type-dependent / a dependent type. This is strictly
1672 // best-effort for now; we may fail to match at all for a dependent type
1673 // in some cases if this is set.
1674 bool IgnoreNonTypeDependent;
1677 SourceLocation MatchLoc;
1679 DependencyChecker(unsigned Depth, bool IgnoreNonTypeDependent,
1680 bool FindLessThanDepth = false)
1681 : Depth(Depth), FindLessThanDepth(FindLessThanDepth),
1682 IgnoreNonTypeDependent(IgnoreNonTypeDependent), Match(false) {}
1684 DependencyChecker(TemplateParameterList *Params, bool IgnoreNonTypeDependent)
1685 : DependencyChecker(Params->getDepth(), IgnoreNonTypeDependent) {}
1687 bool Matches(unsigned ParmDepth, SourceLocation Loc = SourceLocation()) {
1688 if (FindLessThanDepth ^ (ParmDepth >= Depth)) {
1696 bool TraverseStmt(Stmt *S, DataRecursionQueue *Q = nullptr) {
1697 // Prune out non-type-dependent expressions if requested. This can
1698 // sometimes result in us failing to find a template parameter reference
1699 // (if a value-dependent expression creates a dependent type), but this
1700 // mode is best-effort only.
1701 if (auto *E = dyn_cast_or_null<Expr>(S))
1702 if (IgnoreNonTypeDependent && !E->isTypeDependent())
1704 return super::TraverseStmt(S, Q);
1707 bool TraverseTypeLoc(TypeLoc TL) {
1708 if (IgnoreNonTypeDependent && !TL.isNull() &&
1709 !TL.getType()->isDependentType())
1711 return super::TraverseTypeLoc(TL);
1714 bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
1715 return !Matches(TL.getTypePtr()->getDepth(), TL.getNameLoc());
1718 bool VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
1719 // For a best-effort search, keep looking until we find a location.
1720 return IgnoreNonTypeDependent || !Matches(T->getDepth());
1723 bool TraverseTemplateName(TemplateName N) {
1724 if (TemplateTemplateParmDecl *PD =
1725 dyn_cast_or_null<TemplateTemplateParmDecl>(N.getAsTemplateDecl()))
1726 if (Matches(PD->getDepth()))
1728 return super::TraverseTemplateName(N);
1731 bool VisitDeclRefExpr(DeclRefExpr *E) {
1732 if (NonTypeTemplateParmDecl *PD =
1733 dyn_cast<NonTypeTemplateParmDecl>(E->getDecl()))
1734 if (Matches(PD->getDepth(), E->getExprLoc()))
1736 return super::VisitDeclRefExpr(E);
1739 bool VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *T) {
1740 return TraverseType(T->getReplacementType());
1744 VisitSubstTemplateTypeParmPackType(const SubstTemplateTypeParmPackType *T) {
1745 return TraverseTemplateArgument(T->getArgumentPack());
1748 bool TraverseInjectedClassNameType(const InjectedClassNameType *T) {
1749 return TraverseType(T->getInjectedSpecializationType());
1752 } // end anonymous namespace
1754 /// Determines whether a given type depends on the given parameter
1757 DependsOnTemplateParameters(QualType T, TemplateParameterList *Params) {
1758 DependencyChecker Checker(Params, /*IgnoreNonTypeDependent*/false);
1759 Checker.TraverseType(T);
1760 return Checker.Match;
1763 // Find the source range corresponding to the named type in the given
1764 // nested-name-specifier, if any.
1765 static SourceRange getRangeOfTypeInNestedNameSpecifier(ASTContext &Context,
1767 const CXXScopeSpec &SS) {
1768 NestedNameSpecifierLoc NNSLoc(SS.getScopeRep(), SS.location_data());
1769 while (NestedNameSpecifier *NNS = NNSLoc.getNestedNameSpecifier()) {
1770 if (const Type *CurType = NNS->getAsType()) {
1771 if (Context.hasSameUnqualifiedType(T, QualType(CurType, 0)))
1772 return NNSLoc.getTypeLoc().getSourceRange();
1776 NNSLoc = NNSLoc.getPrefix();
1779 return SourceRange();
1782 /// \brief Match the given template parameter lists to the given scope
1783 /// specifier, returning the template parameter list that applies to the
1786 /// \param DeclStartLoc the start of the declaration that has a scope
1787 /// specifier or a template parameter list.
1789 /// \param DeclLoc The location of the declaration itself.
1791 /// \param SS the scope specifier that will be matched to the given template
1792 /// parameter lists. This scope specifier precedes a qualified name that is
1795 /// \param TemplateId The template-id following the scope specifier, if there
1796 /// is one. Used to check for a missing 'template<>'.
1798 /// \param ParamLists the template parameter lists, from the outermost to the
1799 /// innermost template parameter lists.
1801 /// \param IsFriend Whether to apply the slightly different rules for
1802 /// matching template parameters to scope specifiers in friend
1805 /// \param IsExplicitSpecialization will be set true if the entity being
1806 /// declared is an explicit specialization, false otherwise.
1808 /// \returns the template parameter list, if any, that corresponds to the
1809 /// name that is preceded by the scope specifier @p SS. This template
1810 /// parameter list may have template parameters (if we're declaring a
1811 /// template) or may have no template parameters (if we're declaring a
1812 /// template specialization), or may be NULL (if what we're declaring isn't
1813 /// itself a template).
1814 TemplateParameterList *Sema::MatchTemplateParametersToScopeSpecifier(
1815 SourceLocation DeclStartLoc, SourceLocation DeclLoc, const CXXScopeSpec &SS,
1816 TemplateIdAnnotation *TemplateId,
1817 ArrayRef<TemplateParameterList *> ParamLists, bool IsFriend,
1818 bool &IsExplicitSpecialization, bool &Invalid) {
1819 IsExplicitSpecialization = false;
1822 // The sequence of nested types to which we will match up the template
1823 // parameter lists. We first build this list by starting with the type named
1824 // by the nested-name-specifier and walking out until we run out of types.
1825 SmallVector<QualType, 4> NestedTypes;
1827 if (SS.getScopeRep()) {
1828 if (CXXRecordDecl *Record
1829 = dyn_cast_or_null<CXXRecordDecl>(computeDeclContext(SS, true)))
1830 T = Context.getTypeDeclType(Record);
1832 T = QualType(SS.getScopeRep()->getAsType(), 0);
1835 // If we found an explicit specialization that prevents us from needing
1836 // 'template<>' headers, this will be set to the location of that
1837 // explicit specialization.
1838 SourceLocation ExplicitSpecLoc;
1840 while (!T.isNull()) {
1841 NestedTypes.push_back(T);
1843 // Retrieve the parent of a record type.
1844 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
1845 // If this type is an explicit specialization, we're done.
1846 if (ClassTemplateSpecializationDecl *Spec
1847 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
1848 if (!isa<ClassTemplatePartialSpecializationDecl>(Spec) &&
1849 Spec->getSpecializationKind() == TSK_ExplicitSpecialization) {
1850 ExplicitSpecLoc = Spec->getLocation();
1853 } else if (Record->getTemplateSpecializationKind()
1854 == TSK_ExplicitSpecialization) {
1855 ExplicitSpecLoc = Record->getLocation();
1859 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Record->getParent()))
1860 T = Context.getTypeDeclType(Parent);
1866 if (const TemplateSpecializationType *TST
1867 = T->getAs<TemplateSpecializationType>()) {
1868 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
1869 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Template->getDeclContext()))
1870 T = Context.getTypeDeclType(Parent);
1877 // Look one step prior in a dependent template specialization type.
1878 if (const DependentTemplateSpecializationType *DependentTST
1879 = T->getAs<DependentTemplateSpecializationType>()) {
1880 if (NestedNameSpecifier *NNS = DependentTST->getQualifier())
1881 T = QualType(NNS->getAsType(), 0);
1887 // Look one step prior in a dependent name type.
1888 if (const DependentNameType *DependentName = T->getAs<DependentNameType>()){
1889 if (NestedNameSpecifier *NNS = DependentName->getQualifier())
1890 T = QualType(NNS->getAsType(), 0);
1896 // Retrieve the parent of an enumeration type.
1897 if (const EnumType *EnumT = T->getAs<EnumType>()) {
1898 // FIXME: Forward-declared enums require a TSK_ExplicitSpecialization
1900 EnumDecl *Enum = EnumT->getDecl();
1902 // Get to the parent type.
1903 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Enum->getParent()))
1904 T = Context.getTypeDeclType(Parent);
1912 // Reverse the nested types list, since we want to traverse from the outermost
1913 // to the innermost while checking template-parameter-lists.
1914 std::reverse(NestedTypes.begin(), NestedTypes.end());
1916 // C++0x [temp.expl.spec]p17:
1917 // A member or a member template may be nested within many
1918 // enclosing class templates. In an explicit specialization for
1919 // such a member, the member declaration shall be preceded by a
1920 // template<> for each enclosing class template that is
1921 // explicitly specialized.
1922 bool SawNonEmptyTemplateParameterList = false;
1924 auto CheckExplicitSpecialization = [&](SourceRange Range, bool Recovery) {
1925 if (SawNonEmptyTemplateParameterList) {
1926 Diag(DeclLoc, diag::err_specialize_member_of_template)
1927 << !Recovery << Range;
1929 IsExplicitSpecialization = false;
1936 auto DiagnoseMissingExplicitSpecialization = [&] (SourceRange Range) {
1937 // Check that we can have an explicit specialization here.
1938 if (CheckExplicitSpecialization(Range, true))
1941 // We don't have a template header, but we should.
1942 SourceLocation ExpectedTemplateLoc;
1943 if (!ParamLists.empty())
1944 ExpectedTemplateLoc = ParamLists[0]->getTemplateLoc();
1946 ExpectedTemplateLoc = DeclStartLoc;
1948 Diag(DeclLoc, diag::err_template_spec_needs_header)
1950 << FixItHint::CreateInsertion(ExpectedTemplateLoc, "template<> ");
1954 unsigned ParamIdx = 0;
1955 for (unsigned TypeIdx = 0, NumTypes = NestedTypes.size(); TypeIdx != NumTypes;
1957 T = NestedTypes[TypeIdx];
1959 // Whether we expect a 'template<>' header.
1960 bool NeedEmptyTemplateHeader = false;
1962 // Whether we expect a template header with parameters.
1963 bool NeedNonemptyTemplateHeader = false;
1965 // For a dependent type, the set of template parameters that we
1967 TemplateParameterList *ExpectedTemplateParams = nullptr;
1969 // C++0x [temp.expl.spec]p15:
1970 // A member or a member template may be nested within many enclosing
1971 // class templates. In an explicit specialization for such a member, the
1972 // member declaration shall be preceded by a template<> for each
1973 // enclosing class template that is explicitly specialized.
1974 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
1975 if (ClassTemplatePartialSpecializationDecl *Partial
1976 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
1977 ExpectedTemplateParams = Partial->getTemplateParameters();
1978 NeedNonemptyTemplateHeader = true;
1979 } else if (Record->isDependentType()) {
1980 if (Record->getDescribedClassTemplate()) {
1981 ExpectedTemplateParams = Record->getDescribedClassTemplate()
1982 ->getTemplateParameters();
1983 NeedNonemptyTemplateHeader = true;
1985 } else if (ClassTemplateSpecializationDecl *Spec
1986 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
1987 // C++0x [temp.expl.spec]p4:
1988 // Members of an explicitly specialized class template are defined
1989 // in the same manner as members of normal classes, and not using
1990 // the template<> syntax.
1991 if (Spec->getSpecializationKind() != TSK_ExplicitSpecialization)
1992 NeedEmptyTemplateHeader = true;
1995 } else if (Record->getTemplateSpecializationKind()) {
1996 if (Record->getTemplateSpecializationKind()
1997 != TSK_ExplicitSpecialization &&
1998 TypeIdx == NumTypes - 1)
1999 IsExplicitSpecialization = true;
2003 } else if (const TemplateSpecializationType *TST
2004 = T->getAs<TemplateSpecializationType>()) {
2005 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
2006 ExpectedTemplateParams = Template->getTemplateParameters();
2007 NeedNonemptyTemplateHeader = true;
2009 } else if (T->getAs<DependentTemplateSpecializationType>()) {
2010 // FIXME: We actually could/should check the template arguments here
2011 // against the corresponding template parameter list.
2012 NeedNonemptyTemplateHeader = false;
2015 // C++ [temp.expl.spec]p16:
2016 // In an explicit specialization declaration for a member of a class
2017 // template or a member template that ap- pears in namespace scope, the
2018 // member template and some of its enclosing class templates may remain
2019 // unspecialized, except that the declaration shall not explicitly
2020 // specialize a class member template if its en- closing class templates
2021 // are not explicitly specialized as well.
2022 if (ParamIdx < ParamLists.size()) {
2023 if (ParamLists[ParamIdx]->size() == 0) {
2024 if (CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
2028 SawNonEmptyTemplateParameterList = true;
2031 if (NeedEmptyTemplateHeader) {
2032 // If we're on the last of the types, and we need a 'template<>' header
2033 // here, then it's an explicit specialization.
2034 if (TypeIdx == NumTypes - 1)
2035 IsExplicitSpecialization = true;
2037 if (ParamIdx < ParamLists.size()) {
2038 if (ParamLists[ParamIdx]->size() > 0) {
2039 // The header has template parameters when it shouldn't. Complain.
2040 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
2041 diag::err_template_param_list_matches_nontemplate)
2043 << SourceRange(ParamLists[ParamIdx]->getLAngleLoc(),
2044 ParamLists[ParamIdx]->getRAngleLoc())
2045 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
2050 // Consume this template header.
2056 if (DiagnoseMissingExplicitSpecialization(
2057 getRangeOfTypeInNestedNameSpecifier(Context, T, SS)))
2063 if (NeedNonemptyTemplateHeader) {
2064 // In friend declarations we can have template-ids which don't
2065 // depend on the corresponding template parameter lists. But
2066 // assume that empty parameter lists are supposed to match this
2068 if (IsFriend && T->isDependentType()) {
2069 if (ParamIdx < ParamLists.size() &&
2070 DependsOnTemplateParameters(T, ParamLists[ParamIdx]))
2071 ExpectedTemplateParams = nullptr;
2076 if (ParamIdx < ParamLists.size()) {
2077 // Check the template parameter list, if we can.
2078 if (ExpectedTemplateParams &&
2079 !TemplateParameterListsAreEqual(ParamLists[ParamIdx],
2080 ExpectedTemplateParams,
2081 true, TPL_TemplateMatch))
2085 CheckTemplateParameterList(ParamLists[ParamIdx], nullptr,
2086 TPC_ClassTemplateMember))
2093 Diag(DeclLoc, diag::err_template_spec_needs_template_parameters)
2095 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
2101 // If there were at least as many template-ids as there were template
2102 // parameter lists, then there are no template parameter lists remaining for
2103 // the declaration itself.
2104 if (ParamIdx >= ParamLists.size()) {
2105 if (TemplateId && !IsFriend) {
2106 // We don't have a template header for the declaration itself, but we
2108 IsExplicitSpecialization = true;
2109 DiagnoseMissingExplicitSpecialization(SourceRange(TemplateId->LAngleLoc,
2110 TemplateId->RAngleLoc));
2112 // Fabricate an empty template parameter list for the invented header.
2113 return TemplateParameterList::Create(Context, SourceLocation(),
2114 SourceLocation(), None,
2115 SourceLocation(), nullptr);
2121 // If there were too many template parameter lists, complain about that now.
2122 if (ParamIdx < ParamLists.size() - 1) {
2123 bool HasAnyExplicitSpecHeader = false;
2124 bool AllExplicitSpecHeaders = true;
2125 for (unsigned I = ParamIdx, E = ParamLists.size() - 1; I != E; ++I) {
2126 if (ParamLists[I]->size() == 0)
2127 HasAnyExplicitSpecHeader = true;
2129 AllExplicitSpecHeaders = false;
2132 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
2133 AllExplicitSpecHeaders ? diag::warn_template_spec_extra_headers
2134 : diag::err_template_spec_extra_headers)
2135 << SourceRange(ParamLists[ParamIdx]->getTemplateLoc(),
2136 ParamLists[ParamLists.size() - 2]->getRAngleLoc());
2138 // If there was a specialization somewhere, such that 'template<>' is
2139 // not required, and there were any 'template<>' headers, note where the
2140 // specialization occurred.
2141 if (ExplicitSpecLoc.isValid() && HasAnyExplicitSpecHeader)
2142 Diag(ExplicitSpecLoc,
2143 diag::note_explicit_template_spec_does_not_need_header)
2144 << NestedTypes.back();
2146 // We have a template parameter list with no corresponding scope, which
2147 // means that the resulting template declaration can't be instantiated
2148 // properly (we'll end up with dependent nodes when we shouldn't).
2149 if (!AllExplicitSpecHeaders)
2153 // C++ [temp.expl.spec]p16:
2154 // In an explicit specialization declaration for a member of a class
2155 // template or a member template that ap- pears in namespace scope, the
2156 // member template and some of its enclosing class templates may remain
2157 // unspecialized, except that the declaration shall not explicitly
2158 // specialize a class member template if its en- closing class templates
2159 // are not explicitly specialized as well.
2160 if (ParamLists.back()->size() == 0 &&
2161 CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
2165 // Return the last template parameter list, which corresponds to the
2166 // entity being declared.
2167 return ParamLists.back();
2170 void Sema::NoteAllFoundTemplates(TemplateName Name) {
2171 if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
2172 Diag(Template->getLocation(), diag::note_template_declared_here)
2173 << (isa<FunctionTemplateDecl>(Template)
2175 : isa<ClassTemplateDecl>(Template)
2177 : isa<VarTemplateDecl>(Template)
2179 : isa<TypeAliasTemplateDecl>(Template) ? 3 : 4)
2180 << Template->getDeclName();
2184 if (OverloadedTemplateStorage *OST = Name.getAsOverloadedTemplate()) {
2185 for (OverloadedTemplateStorage::iterator I = OST->begin(),
2188 Diag((*I)->getLocation(), diag::note_template_declared_here)
2189 << 0 << (*I)->getDeclName();
2196 checkBuiltinTemplateIdType(Sema &SemaRef, BuiltinTemplateDecl *BTD,
2197 const SmallVectorImpl<TemplateArgument> &Converted,
2198 SourceLocation TemplateLoc,
2199 TemplateArgumentListInfo &TemplateArgs) {
2200 ASTContext &Context = SemaRef.getASTContext();
2201 switch (BTD->getBuiltinTemplateKind()) {
2202 case BTK__make_integer_seq: {
2203 // Specializations of __make_integer_seq<S, T, N> are treated like
2204 // S<T, 0, ..., N-1>.
2206 // C++14 [inteseq.intseq]p1:
2207 // T shall be an integer type.
2208 if (!Converted[1].getAsType()->isIntegralType(Context)) {
2209 SemaRef.Diag(TemplateArgs[1].getLocation(),
2210 diag::err_integer_sequence_integral_element_type);
2214 // C++14 [inteseq.make]p1:
2215 // If N is negative the program is ill-formed.
2216 TemplateArgument NumArgsArg = Converted[2];
2217 llvm::APSInt NumArgs = NumArgsArg.getAsIntegral();
2219 SemaRef.Diag(TemplateArgs[2].getLocation(),
2220 diag::err_integer_sequence_negative_length);
2224 QualType ArgTy = NumArgsArg.getIntegralType();
2225 TemplateArgumentListInfo SyntheticTemplateArgs;
2226 // The type argument gets reused as the first template argument in the
2227 // synthetic template argument list.
2228 SyntheticTemplateArgs.addArgument(TemplateArgs[1]);
2229 // Expand N into 0 ... N-1.
2230 for (llvm::APSInt I(NumArgs.getBitWidth(), NumArgs.isUnsigned());
2232 TemplateArgument TA(Context, I, ArgTy);
2233 SyntheticTemplateArgs.addArgument(SemaRef.getTrivialTemplateArgumentLoc(
2234 TA, ArgTy, TemplateArgs[2].getLocation()));
2236 // The first template argument will be reused as the template decl that
2237 // our synthetic template arguments will be applied to.
2238 return SemaRef.CheckTemplateIdType(Converted[0].getAsTemplate(),
2239 TemplateLoc, SyntheticTemplateArgs);
2242 case BTK__type_pack_element:
2243 // Specializations of
2244 // __type_pack_element<Index, T_1, ..., T_N>
2245 // are treated like T_Index.
2246 assert(Converted.size() == 2 &&
2247 "__type_pack_element should be given an index and a parameter pack");
2249 // If the Index is out of bounds, the program is ill-formed.
2250 TemplateArgument IndexArg = Converted[0], Ts = Converted[1];
2251 llvm::APSInt Index = IndexArg.getAsIntegral();
2252 assert(Index >= 0 && "the index used with __type_pack_element should be of "
2253 "type std::size_t, and hence be non-negative");
2254 if (Index >= Ts.pack_size()) {
2255 SemaRef.Diag(TemplateArgs[0].getLocation(),
2256 diag::err_type_pack_element_out_of_bounds);
2260 // We simply return the type at index `Index`.
2261 auto Nth = std::next(Ts.pack_begin(), Index.getExtValue());
2262 return Nth->getAsType();
2264 llvm_unreachable("unexpected BuiltinTemplateDecl!");
2267 QualType Sema::CheckTemplateIdType(TemplateName Name,
2268 SourceLocation TemplateLoc,
2269 TemplateArgumentListInfo &TemplateArgs) {
2270 DependentTemplateName *DTN
2271 = Name.getUnderlying().getAsDependentTemplateName();
2272 if (DTN && DTN->isIdentifier())
2273 // When building a template-id where the template-name is dependent,
2274 // assume the template is a type template. Either our assumption is
2275 // correct, or the code is ill-formed and will be diagnosed when the
2276 // dependent name is substituted.
2277 return Context.getDependentTemplateSpecializationType(ETK_None,
2278 DTN->getQualifier(),
2279 DTN->getIdentifier(),
2282 TemplateDecl *Template = Name.getAsTemplateDecl();
2283 if (!Template || isa<FunctionTemplateDecl>(Template) ||
2284 isa<VarTemplateDecl>(Template)) {
2285 // We might have a substituted template template parameter pack. If so,
2286 // build a template specialization type for it.
2287 if (Name.getAsSubstTemplateTemplateParmPack())
2288 return Context.getTemplateSpecializationType(Name, TemplateArgs);
2290 Diag(TemplateLoc, diag::err_template_id_not_a_type)
2292 NoteAllFoundTemplates(Name);
2296 // Check that the template argument list is well-formed for this
2298 SmallVector<TemplateArgument, 4> Converted;
2299 if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs,
2305 bool InstantiationDependent = false;
2306 if (TypeAliasTemplateDecl *AliasTemplate =
2307 dyn_cast<TypeAliasTemplateDecl>(Template)) {
2308 // Find the canonical type for this type alias template specialization.
2309 TypeAliasDecl *Pattern = AliasTemplate->getTemplatedDecl();
2310 if (Pattern->isInvalidDecl())
2313 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
2316 // Only substitute for the innermost template argument list.
2317 MultiLevelTemplateArgumentList TemplateArgLists;
2318 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
2319 unsigned Depth = AliasTemplate->getTemplateParameters()->getDepth();
2320 for (unsigned I = 0; I < Depth; ++I)
2321 TemplateArgLists.addOuterTemplateArguments(None);
2323 LocalInstantiationScope Scope(*this);
2324 InstantiatingTemplate Inst(*this, TemplateLoc, Template);
2325 if (Inst.isInvalid())
2328 CanonType = SubstType(Pattern->getUnderlyingType(),
2329 TemplateArgLists, AliasTemplate->getLocation(),
2330 AliasTemplate->getDeclName());
2331 if (CanonType.isNull())
2333 } else if (Name.isDependent() ||
2334 TemplateSpecializationType::anyDependentTemplateArguments(
2335 TemplateArgs, InstantiationDependent)) {
2336 // This class template specialization is a dependent
2337 // type. Therefore, its canonical type is another class template
2338 // specialization type that contains all of the converted
2339 // arguments in canonical form. This ensures that, e.g., A<T> and
2340 // A<T, T> have identical types when A is declared as:
2342 // template<typename T, typename U = T> struct A;
2343 CanonType = Context.getCanonicalTemplateSpecializationType(Name, Converted);
2345 // This might work out to be a current instantiation, in which
2346 // case the canonical type needs to be the InjectedClassNameType.
2348 // TODO: in theory this could be a simple hashtable lookup; most
2349 // changes to CurContext don't change the set of current
2351 if (isa<ClassTemplateDecl>(Template)) {
2352 for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) {
2353 // If we get out to a namespace, we're done.
2354 if (Ctx->isFileContext()) break;
2356 // If this isn't a record, keep looking.
2357 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx);
2358 if (!Record) continue;
2360 // Look for one of the two cases with InjectedClassNameTypes
2361 // and check whether it's the same template.
2362 if (!isa<ClassTemplatePartialSpecializationDecl>(Record) &&
2363 !Record->getDescribedClassTemplate())
2366 // Fetch the injected class name type and check whether its
2367 // injected type is equal to the type we just built.
2368 QualType ICNT = Context.getTypeDeclType(Record);
2369 QualType Injected = cast<InjectedClassNameType>(ICNT)
2370 ->getInjectedSpecializationType();
2372 if (CanonType != Injected->getCanonicalTypeInternal())
2375 // If so, the canonical type of this TST is the injected
2376 // class name type of the record we just found.
2377 assert(ICNT.isCanonical());
2382 } else if (ClassTemplateDecl *ClassTemplate
2383 = dyn_cast<ClassTemplateDecl>(Template)) {
2384 // Find the class template specialization declaration that
2385 // corresponds to these arguments.
2386 void *InsertPos = nullptr;
2387 ClassTemplateSpecializationDecl *Decl
2388 = ClassTemplate->findSpecialization(Converted, InsertPos);
2390 // This is the first time we have referenced this class template
2391 // specialization. Create the canonical declaration and add it to
2392 // the set of specializations.
2393 Decl = ClassTemplateSpecializationDecl::Create(Context,
2394 ClassTemplate->getTemplatedDecl()->getTagKind(),
2395 ClassTemplate->getDeclContext(),
2396 ClassTemplate->getTemplatedDecl()->getLocStart(),
2397 ClassTemplate->getLocation(),
2399 Converted, nullptr);
2400 ClassTemplate->AddSpecialization(Decl, InsertPos);
2401 if (ClassTemplate->isOutOfLine())
2402 Decl->setLexicalDeclContext(ClassTemplate->getLexicalDeclContext());
2405 // Diagnose uses of this specialization.
2406 (void)DiagnoseUseOfDecl(Decl, TemplateLoc);
2408 CanonType = Context.getTypeDeclType(Decl);
2409 assert(isa<RecordType>(CanonType) &&
2410 "type of non-dependent specialization is not a RecordType");
2411 } else if (auto *BTD = dyn_cast<BuiltinTemplateDecl>(Template)) {
2412 CanonType = checkBuiltinTemplateIdType(*this, BTD, Converted, TemplateLoc,
2416 // Build the fully-sugared type for this class template
2417 // specialization, which refers back to the class template
2418 // specialization we created or found.
2419 return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType);
2423 Sema::ActOnTemplateIdType(CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
2424 TemplateTy TemplateD, SourceLocation TemplateLoc,
2425 SourceLocation LAngleLoc,
2426 ASTTemplateArgsPtr TemplateArgsIn,
2427 SourceLocation RAngleLoc,
2428 bool IsCtorOrDtorName) {
2432 TemplateName Template = TemplateD.get();
2434 // Translate the parser's template argument list in our AST format.
2435 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
2436 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
2438 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
2440 = Context.getDependentTemplateSpecializationType(ETK_None,
2441 DTN->getQualifier(),
2442 DTN->getIdentifier(),
2444 // Build type-source information.
2446 DependentTemplateSpecializationTypeLoc SpecTL
2447 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
2448 SpecTL.setElaboratedKeywordLoc(SourceLocation());
2449 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
2450 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2451 SpecTL.setTemplateNameLoc(TemplateLoc);
2452 SpecTL.setLAngleLoc(LAngleLoc);
2453 SpecTL.setRAngleLoc(RAngleLoc);
2454 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
2455 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
2456 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
2459 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
2461 if (Result.isNull())
2464 // Build type-source information.
2466 TemplateSpecializationTypeLoc SpecTL
2467 = TLB.push<TemplateSpecializationTypeLoc>(Result);
2468 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2469 SpecTL.setTemplateNameLoc(TemplateLoc);
2470 SpecTL.setLAngleLoc(LAngleLoc);
2471 SpecTL.setRAngleLoc(RAngleLoc);
2472 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
2473 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
2475 // NOTE: avoid constructing an ElaboratedTypeLoc if this is a
2476 // constructor or destructor name (in such a case, the scope specifier
2477 // will be attached to the enclosing Decl or Expr node).
2478 if (SS.isNotEmpty() && !IsCtorOrDtorName) {
2479 // Create an elaborated-type-specifier containing the nested-name-specifier.
2480 Result = Context.getElaboratedType(ETK_None, SS.getScopeRep(), Result);
2481 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
2482 ElabTL.setElaboratedKeywordLoc(SourceLocation());
2483 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
2486 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
2489 TypeResult Sema::ActOnTagTemplateIdType(TagUseKind TUK,
2490 TypeSpecifierType TagSpec,
2491 SourceLocation TagLoc,
2493 SourceLocation TemplateKWLoc,
2494 TemplateTy TemplateD,
2495 SourceLocation TemplateLoc,
2496 SourceLocation LAngleLoc,
2497 ASTTemplateArgsPtr TemplateArgsIn,
2498 SourceLocation RAngleLoc) {
2499 TemplateName Template = TemplateD.get();
2501 // Translate the parser's template argument list in our AST format.
2502 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
2503 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
2505 // Determine the tag kind
2506 TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
2507 ElaboratedTypeKeyword Keyword
2508 = TypeWithKeyword::getKeywordForTagTypeKind(TagKind);
2510 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
2511 QualType T = Context.getDependentTemplateSpecializationType(Keyword,
2512 DTN->getQualifier(),
2513 DTN->getIdentifier(),
2516 // Build type-source information.
2518 DependentTemplateSpecializationTypeLoc SpecTL
2519 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
2520 SpecTL.setElaboratedKeywordLoc(TagLoc);
2521 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
2522 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2523 SpecTL.setTemplateNameLoc(TemplateLoc);
2524 SpecTL.setLAngleLoc(LAngleLoc);
2525 SpecTL.setRAngleLoc(RAngleLoc);
2526 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
2527 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
2528 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
2531 if (TypeAliasTemplateDecl *TAT =
2532 dyn_cast_or_null<TypeAliasTemplateDecl>(Template.getAsTemplateDecl())) {
2533 // C++0x [dcl.type.elab]p2:
2534 // If the identifier resolves to a typedef-name or the simple-template-id
2535 // resolves to an alias template specialization, the
2536 // elaborated-type-specifier is ill-formed.
2537 Diag(TemplateLoc, diag::err_tag_reference_non_tag)
2538 << TAT << NTK_TypeAliasTemplate << TagKind;
2539 Diag(TAT->getLocation(), diag::note_declared_at);
2542 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
2543 if (Result.isNull())
2544 return TypeResult(true);
2546 // Check the tag kind
2547 if (const RecordType *RT = Result->getAs<RecordType>()) {
2548 RecordDecl *D = RT->getDecl();
2550 IdentifierInfo *Id = D->getIdentifier();
2551 assert(Id && "templated class must have an identifier");
2553 if (!isAcceptableTagRedeclaration(D, TagKind, TUK == TUK_Definition,
2555 Diag(TagLoc, diag::err_use_with_wrong_tag)
2557 << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName());
2558 Diag(D->getLocation(), diag::note_previous_use);
2562 // Provide source-location information for the template specialization.
2564 TemplateSpecializationTypeLoc SpecTL
2565 = TLB.push<TemplateSpecializationTypeLoc>(Result);
2566 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2567 SpecTL.setTemplateNameLoc(TemplateLoc);
2568 SpecTL.setLAngleLoc(LAngleLoc);
2569 SpecTL.setRAngleLoc(RAngleLoc);
2570 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
2571 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
2573 // Construct an elaborated type containing the nested-name-specifier (if any)
2575 Result = Context.getElaboratedType(Keyword, SS.getScopeRep(), Result);
2576 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
2577 ElabTL.setElaboratedKeywordLoc(TagLoc);
2578 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
2579 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
2582 static bool CheckTemplateSpecializationScope(Sema &S, NamedDecl *Specialized,
2583 NamedDecl *PrevDecl,
2585 bool IsPartialSpecialization);
2587 static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D);
2589 static bool isTemplateArgumentTemplateParameter(
2590 const TemplateArgument &Arg, unsigned Depth, unsigned Index) {
2591 switch (Arg.getKind()) {
2592 case TemplateArgument::Null:
2593 case TemplateArgument::NullPtr:
2594 case TemplateArgument::Integral:
2595 case TemplateArgument::Declaration:
2596 case TemplateArgument::Pack:
2597 case TemplateArgument::TemplateExpansion:
2600 case TemplateArgument::Type: {
2601 QualType Type = Arg.getAsType();
2602 const TemplateTypeParmType *TPT =
2603 Arg.getAsType()->getAs<TemplateTypeParmType>();
2604 return TPT && !Type.hasQualifiers() &&
2605 TPT->getDepth() == Depth && TPT->getIndex() == Index;
2608 case TemplateArgument::Expression: {
2609 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg.getAsExpr());
2610 if (!DRE || !DRE->getDecl())
2612 const NonTypeTemplateParmDecl *NTTP =
2613 dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl());
2614 return NTTP && NTTP->getDepth() == Depth && NTTP->getIndex() == Index;
2617 case TemplateArgument::Template:
2618 const TemplateTemplateParmDecl *TTP =
2619 dyn_cast_or_null<TemplateTemplateParmDecl>(
2620 Arg.getAsTemplateOrTemplatePattern().getAsTemplateDecl());
2621 return TTP && TTP->getDepth() == Depth && TTP->getIndex() == Index;
2623 llvm_unreachable("unexpected kind of template argument");
2626 static bool isSameAsPrimaryTemplate(TemplateParameterList *Params,
2627 ArrayRef<TemplateArgument> Args) {
2628 if (Params->size() != Args.size())
2631 unsigned Depth = Params->getDepth();
2633 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
2634 TemplateArgument Arg = Args[I];
2636 // If the parameter is a pack expansion, the argument must be a pack
2637 // whose only element is a pack expansion.
2638 if (Params->getParam(I)->isParameterPack()) {
2639 if (Arg.getKind() != TemplateArgument::Pack || Arg.pack_size() != 1 ||
2640 !Arg.pack_begin()->isPackExpansion())
2642 Arg = Arg.pack_begin()->getPackExpansionPattern();
2645 if (!isTemplateArgumentTemplateParameter(Arg, Depth, I))
2652 /// Convert the parser's template argument list representation into our form.
2653 static TemplateArgumentListInfo
2654 makeTemplateArgumentListInfo(Sema &S, TemplateIdAnnotation &TemplateId) {
2655 TemplateArgumentListInfo TemplateArgs(TemplateId.LAngleLoc,
2656 TemplateId.RAngleLoc);
2657 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId.getTemplateArgs(),
2658 TemplateId.NumArgs);
2659 S.translateTemplateArguments(TemplateArgsPtr, TemplateArgs);
2660 return TemplateArgs;
2663 template<typename PartialSpecDecl>
2664 static void checkMoreSpecializedThanPrimary(Sema &S, PartialSpecDecl *Partial) {
2665 if (Partial->getDeclContext()->isDependentContext())
2668 // FIXME: Get the TDK from deduction in order to provide better diagnostics
2669 // for non-substitution-failure issues?
2670 TemplateDeductionInfo Info(Partial->getLocation());
2671 if (S.isMoreSpecializedThanPrimary(Partial, Info))
2674 auto *Template = Partial->getSpecializedTemplate();
2675 S.Diag(Partial->getLocation(),
2676 diag::ext_partial_spec_not_more_specialized_than_primary)
2677 << isa<VarTemplateDecl>(Template);
2679 if (Info.hasSFINAEDiagnostic()) {
2680 PartialDiagnosticAt Diag = {SourceLocation(),
2681 PartialDiagnostic::NullDiagnostic()};
2682 Info.takeSFINAEDiagnostic(Diag);
2683 SmallString<128> SFINAEArgString;
2684 Diag.second.EmitToString(S.getDiagnostics(), SFINAEArgString);
2686 diag::note_partial_spec_not_more_specialized_than_primary)
2690 S.Diag(Template->getLocation(), diag::note_template_decl_here);
2693 template<typename PartialSpecDecl>
2694 static void checkTemplatePartialSpecialization(Sema &S,
2695 PartialSpecDecl *Partial) {
2696 // C++1z [temp.class.spec]p8: (DR1495)
2697 // - The specialization shall be more specialized than the primary
2698 // template (14.5.5.2).
2699 checkMoreSpecializedThanPrimary(S, Partial);
2701 // C++ [temp.class.spec]p8: (DR1315)
2702 // - Each template-parameter shall appear at least once in the
2703 // template-id outside a non-deduced context.
2704 // C++1z [temp.class.spec.match]p3 (P0127R2)
2705 // If the template arguments of a partial specialization cannot be
2706 // deduced because of the structure of its template-parameter-list
2707 // and the template-id, the program is ill-formed.
2708 auto *TemplateParams = Partial->getTemplateParameters();
2709 llvm::SmallBitVector DeducibleParams(TemplateParams->size());
2710 S.MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
2711 TemplateParams->getDepth(), DeducibleParams);
2713 if (!DeducibleParams.all()) {
2714 unsigned NumNonDeducible = DeducibleParams.size() - DeducibleParams.count();
2715 S.Diag(Partial->getLocation(), diag::ext_partial_specs_not_deducible)
2716 << isa<VarTemplatePartialSpecializationDecl>(Partial)
2717 << (NumNonDeducible > 1)
2718 << SourceRange(Partial->getLocation(),
2719 Partial->getTemplateArgsAsWritten()->RAngleLoc);
2720 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) {
2721 if (!DeducibleParams[I]) {
2722 NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I));
2723 if (Param->getDeclName())
2724 S.Diag(Param->getLocation(),
2725 diag::note_partial_spec_unused_parameter)
2726 << Param->getDeclName();
2728 S.Diag(Param->getLocation(),
2729 diag::note_partial_spec_unused_parameter)
2736 void Sema::CheckTemplatePartialSpecialization(
2737 ClassTemplatePartialSpecializationDecl *Partial) {
2738 checkTemplatePartialSpecialization(*this, Partial);
2741 void Sema::CheckTemplatePartialSpecialization(
2742 VarTemplatePartialSpecializationDecl *Partial) {
2743 checkTemplatePartialSpecialization(*this, Partial);
2746 DeclResult Sema::ActOnVarTemplateSpecialization(
2747 Scope *S, Declarator &D, TypeSourceInfo *DI, SourceLocation TemplateKWLoc,
2748 TemplateParameterList *TemplateParams, StorageClass SC,
2749 bool IsPartialSpecialization) {
2750 // D must be variable template id.
2751 assert(D.getName().getKind() == UnqualifiedId::IK_TemplateId &&
2752 "Variable template specialization is declared with a template it.");
2754 TemplateIdAnnotation *TemplateId = D.getName().TemplateId;
2755 TemplateArgumentListInfo TemplateArgs =
2756 makeTemplateArgumentListInfo(*this, *TemplateId);
2757 SourceLocation TemplateNameLoc = D.getIdentifierLoc();
2758 SourceLocation LAngleLoc = TemplateId->LAngleLoc;
2759 SourceLocation RAngleLoc = TemplateId->RAngleLoc;
2761 TemplateName Name = TemplateId->Template.get();
2763 // The template-id must name a variable template.
2764 VarTemplateDecl *VarTemplate =
2765 dyn_cast_or_null<VarTemplateDecl>(Name.getAsTemplateDecl());
2767 NamedDecl *FnTemplate;
2768 if (auto *OTS = Name.getAsOverloadedTemplate())
2769 FnTemplate = *OTS->begin();
2771 FnTemplate = dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl());
2773 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template_but_method)
2774 << FnTemplate->getDeclName();
2775 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template)
2776 << IsPartialSpecialization;
2779 // Check for unexpanded parameter packs in any of the template arguments.
2780 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2781 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
2782 UPPC_PartialSpecialization))
2785 // Check that the template argument list is well-formed for this
2787 SmallVector<TemplateArgument, 4> Converted;
2788 if (CheckTemplateArgumentList(VarTemplate, TemplateNameLoc, TemplateArgs,
2792 // Find the variable template (partial) specialization declaration that
2793 // corresponds to these arguments.
2794 if (IsPartialSpecialization) {
2795 if (CheckTemplatePartialSpecializationArgs(TemplateNameLoc, VarTemplate,
2796 TemplateArgs.size(), Converted))
2799 // FIXME: Move these checks to CheckTemplatePartialSpecializationArgs so we
2800 // also do them during instantiation.
2801 bool InstantiationDependent;
2802 if (!Name.isDependent() &&
2803 !TemplateSpecializationType::anyDependentTemplateArguments(
2804 TemplateArgs.arguments(),
2805 InstantiationDependent)) {
2806 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
2807 << VarTemplate->getDeclName();
2808 IsPartialSpecialization = false;
2811 if (isSameAsPrimaryTemplate(VarTemplate->getTemplateParameters(),
2813 // C++ [temp.class.spec]p9b3:
2815 // -- The argument list of the specialization shall not be identical
2816 // to the implicit argument list of the primary template.
2817 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
2818 << /*variable template*/ 1
2819 << /*is definition*/(SC != SC_Extern && !CurContext->isRecord())
2820 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
2821 // FIXME: Recover from this by treating the declaration as a redeclaration
2822 // of the primary template.
2827 void *InsertPos = nullptr;
2828 VarTemplateSpecializationDecl *PrevDecl = nullptr;
2830 if (IsPartialSpecialization)
2831 // FIXME: Template parameter list matters too
2832 PrevDecl = VarTemplate->findPartialSpecialization(Converted, InsertPos);
2834 PrevDecl = VarTemplate->findSpecialization(Converted, InsertPos);
2836 VarTemplateSpecializationDecl *Specialization = nullptr;
2838 // Check whether we can declare a variable template specialization in
2839 // the current scope.
2840 if (CheckTemplateSpecializationScope(*this, VarTemplate, PrevDecl,
2842 IsPartialSpecialization))
2845 if (PrevDecl && PrevDecl->getSpecializationKind() == TSK_Undeclared) {
2846 // Since the only prior variable template specialization with these
2847 // arguments was referenced but not declared, reuse that
2848 // declaration node as our own, updating its source location and
2849 // the list of outer template parameters to reflect our new declaration.
2850 Specialization = PrevDecl;
2851 Specialization->setLocation(TemplateNameLoc);
2853 } else if (IsPartialSpecialization) {
2854 // Create a new class template partial specialization declaration node.
2855 VarTemplatePartialSpecializationDecl *PrevPartial =
2856 cast_or_null<VarTemplatePartialSpecializationDecl>(PrevDecl);
2857 VarTemplatePartialSpecializationDecl *Partial =
2858 VarTemplatePartialSpecializationDecl::Create(
2859 Context, VarTemplate->getDeclContext(), TemplateKWLoc,
2860 TemplateNameLoc, TemplateParams, VarTemplate, DI->getType(), DI, SC,
2861 Converted, TemplateArgs);
2864 VarTemplate->AddPartialSpecialization(Partial, InsertPos);
2865 Specialization = Partial;
2867 // If we are providing an explicit specialization of a member variable
2868 // template specialization, make a note of that.
2869 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
2870 PrevPartial->setMemberSpecialization();
2872 CheckTemplatePartialSpecialization(Partial);
2874 // Create a new class template specialization declaration node for
2875 // this explicit specialization or friend declaration.
2876 Specialization = VarTemplateSpecializationDecl::Create(
2877 Context, VarTemplate->getDeclContext(), TemplateKWLoc, TemplateNameLoc,
2878 VarTemplate, DI->getType(), DI, SC, Converted);
2879 Specialization->setTemplateArgsInfo(TemplateArgs);
2882 VarTemplate->AddSpecialization(Specialization, InsertPos);
2885 // C++ [temp.expl.spec]p6:
2886 // If a template, a member template or the member of a class template is
2887 // explicitly specialized then that specialization shall be declared
2888 // before the first use of that specialization that would cause an implicit
2889 // instantiation to take place, in every translation unit in which such a
2890 // use occurs; no diagnostic is required.
2891 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
2893 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
2894 // Is there any previous explicit specialization declaration?
2895 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
2902 SourceRange Range(TemplateNameLoc, RAngleLoc);
2903 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
2906 Diag(PrevDecl->getPointOfInstantiation(),
2907 diag::note_instantiation_required_here)
2908 << (PrevDecl->getTemplateSpecializationKind() !=
2909 TSK_ImplicitInstantiation);
2914 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
2915 Specialization->setLexicalDeclContext(CurContext);
2917 // Add the specialization into its lexical context, so that it can
2918 // be seen when iterating through the list of declarations in that
2919 // context. However, specializations are not found by name lookup.
2920 CurContext->addDecl(Specialization);
2922 // Note that this is an explicit specialization.
2923 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
2926 // Check that this isn't a redefinition of this specialization,
2927 // merging with previous declarations.
2928 LookupResult PrevSpec(*this, GetNameForDeclarator(D), LookupOrdinaryName,
2930 PrevSpec.addDecl(PrevDecl);
2931 D.setRedeclaration(CheckVariableDeclaration(Specialization, PrevSpec));
2932 } else if (Specialization->isStaticDataMember() &&
2933 Specialization->isOutOfLine()) {
2934 Specialization->setAccess(VarTemplate->getAccess());
2937 // Link instantiations of static data members back to the template from
2938 // which they were instantiated.
2939 if (Specialization->isStaticDataMember())
2940 Specialization->setInstantiationOfStaticDataMember(
2941 VarTemplate->getTemplatedDecl(),
2942 Specialization->getSpecializationKind());
2944 return Specialization;
2948 /// \brief A partial specialization whose template arguments have matched
2949 /// a given template-id.
2950 struct PartialSpecMatchResult {
2951 VarTemplatePartialSpecializationDecl *Partial;
2952 TemplateArgumentList *Args;
2954 } // end anonymous namespace
2957 Sema::CheckVarTemplateId(VarTemplateDecl *Template, SourceLocation TemplateLoc,
2958 SourceLocation TemplateNameLoc,
2959 const TemplateArgumentListInfo &TemplateArgs) {
2960 assert(Template && "A variable template id without template?");
2962 // Check that the template argument list is well-formed for this template.
2963 SmallVector<TemplateArgument, 4> Converted;
2964 if (CheckTemplateArgumentList(
2965 Template, TemplateNameLoc,
2966 const_cast<TemplateArgumentListInfo &>(TemplateArgs), false,
2970 // Find the variable template specialization declaration that
2971 // corresponds to these arguments.
2972 void *InsertPos = nullptr;
2973 if (VarTemplateSpecializationDecl *Spec = Template->findSpecialization(
2974 Converted, InsertPos)) {
2975 checkSpecializationVisibility(TemplateNameLoc, Spec);
2976 // If we already have a variable template specialization, return it.
2980 // This is the first time we have referenced this variable template
2981 // specialization. Create the canonical declaration and add it to
2982 // the set of specializations, based on the closest partial specialization
2983 // that it represents. That is,
2984 VarDecl *InstantiationPattern = Template->getTemplatedDecl();
2985 TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack,
2987 TemplateArgumentList *InstantiationArgs = &TemplateArgList;
2988 bool AmbiguousPartialSpec = false;
2989 typedef PartialSpecMatchResult MatchResult;
2990 SmallVector<MatchResult, 4> Matched;
2991 SourceLocation PointOfInstantiation = TemplateNameLoc;
2992 TemplateSpecCandidateSet FailedCandidates(PointOfInstantiation,
2993 /*ForTakingAddress=*/false);
2995 // 1. Attempt to find the closest partial specialization that this
2996 // specializes, if any.
2997 // If any of the template arguments is dependent, then this is probably
2998 // a placeholder for an incomplete declarative context; which must be
2999 // complete by instantiation time. Thus, do not search through the partial
3000 // specializations yet.
3001 // TODO: Unify with InstantiateClassTemplateSpecialization()?
3002 // Perhaps better after unification of DeduceTemplateArguments() and
3003 // getMoreSpecializedPartialSpecialization().
3004 bool InstantiationDependent = false;
3005 if (!TemplateSpecializationType::anyDependentTemplateArguments(
3006 TemplateArgs, InstantiationDependent)) {
3008 SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
3009 Template->getPartialSpecializations(PartialSpecs);
3011 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) {
3012 VarTemplatePartialSpecializationDecl *Partial = PartialSpecs[I];
3013 TemplateDeductionInfo Info(FailedCandidates.getLocation());
3015 if (TemplateDeductionResult Result =
3016 DeduceTemplateArguments(Partial, TemplateArgList, Info)) {
3017 // Store the failed-deduction information for use in diagnostics, later.
3018 // TODO: Actually use the failed-deduction info?
3019 FailedCandidates.addCandidate().set(
3020 DeclAccessPair::make(Template, AS_public), Partial,
3021 MakeDeductionFailureInfo(Context, Result, Info));
3024 Matched.push_back(PartialSpecMatchResult());
3025 Matched.back().Partial = Partial;
3026 Matched.back().Args = Info.take();
3030 if (Matched.size() >= 1) {
3031 SmallVector<MatchResult, 4>::iterator Best = Matched.begin();
3032 if (Matched.size() == 1) {
3033 // -- If exactly one matching specialization is found, the
3034 // instantiation is generated from that specialization.
3035 // We don't need to do anything for this.
3037 // -- If more than one matching specialization is found, the
3038 // partial order rules (14.5.4.2) are used to determine
3039 // whether one of the specializations is more specialized
3040 // than the others. If none of the specializations is more
3041 // specialized than all of the other matching
3042 // specializations, then the use of the variable template is
3043 // ambiguous and the program is ill-formed.
3044 for (SmallVector<MatchResult, 4>::iterator P = Best + 1,
3045 PEnd = Matched.end();
3047 if (getMoreSpecializedPartialSpecialization(P->Partial, Best->Partial,
3048 PointOfInstantiation) ==
3053 // Determine if the best partial specialization is more specialized than
3055 for (SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
3056 PEnd = Matched.end();
3058 if (P != Best && getMoreSpecializedPartialSpecialization(
3059 P->Partial, Best->Partial,
3060 PointOfInstantiation) != Best->Partial) {
3061 AmbiguousPartialSpec = true;
3067 // Instantiate using the best variable template partial specialization.
3068 InstantiationPattern = Best->Partial;
3069 InstantiationArgs = Best->Args;
3071 // -- If no match is found, the instantiation is generated
3072 // from the primary template.
3073 // InstantiationPattern = Template->getTemplatedDecl();
3077 // 2. Create the canonical declaration.
3078 // Note that we do not instantiate a definition until we see an odr-use
3079 // in DoMarkVarDeclReferenced().
3080 // FIXME: LateAttrs et al.?
3081 VarTemplateSpecializationDecl *Decl = BuildVarTemplateInstantiation(
3082 Template, InstantiationPattern, *InstantiationArgs, TemplateArgs,
3083 Converted, TemplateNameLoc, InsertPos /*, LateAttrs, StartingScope*/);
3087 if (AmbiguousPartialSpec) {
3088 // Partial ordering did not produce a clear winner. Complain.
3089 Decl->setInvalidDecl();
3090 Diag(PointOfInstantiation, diag::err_partial_spec_ordering_ambiguous)
3093 // Print the matching partial specializations.
3094 for (MatchResult P : Matched)
3095 Diag(P.Partial->getLocation(), diag::note_partial_spec_match)
3096 << getTemplateArgumentBindingsText(P.Partial->getTemplateParameters(),
3101 if (VarTemplatePartialSpecializationDecl *D =
3102 dyn_cast<VarTemplatePartialSpecializationDecl>(InstantiationPattern))
3103 Decl->setInstantiationOf(D, InstantiationArgs);
3105 checkSpecializationVisibility(TemplateNameLoc, Decl);
3107 assert(Decl && "No variable template specialization?");
3112 Sema::CheckVarTemplateId(const CXXScopeSpec &SS,
3113 const DeclarationNameInfo &NameInfo,
3114 VarTemplateDecl *Template, SourceLocation TemplateLoc,
3115 const TemplateArgumentListInfo *TemplateArgs) {
3117 DeclResult Decl = CheckVarTemplateId(Template, TemplateLoc, NameInfo.getLoc(),
3119 if (Decl.isInvalid())
3122 VarDecl *Var = cast<VarDecl>(Decl.get());
3123 if (!Var->getTemplateSpecializationKind())
3124 Var->setTemplateSpecializationKind(TSK_ImplicitInstantiation,
3127 // Build an ordinary singleton decl ref.
3128 return BuildDeclarationNameExpr(SS, NameInfo, Var,
3129 /*FoundD=*/nullptr, TemplateArgs);
3132 ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS,
3133 SourceLocation TemplateKWLoc,
3136 const TemplateArgumentListInfo *TemplateArgs) {
3137 // FIXME: Can we do any checking at this point? I guess we could check the
3138 // template arguments that we have against the template name, if the template
3139 // name refers to a single template. That's not a terribly common case,
3141 // foo<int> could identify a single function unambiguously
3142 // This approach does NOT work, since f<int>(1);
3143 // gets resolved prior to resorting to overload resolution
3144 // i.e., template<class T> void f(double);
3145 // vs template<class T, class U> void f(U);
3147 // These should be filtered out by our callers.
3148 assert(!R.empty() && "empty lookup results when building templateid");
3149 assert(!R.isAmbiguous() && "ambiguous lookup when building templateid");
3151 // In C++1y, check variable template ids.
3152 bool InstantiationDependent;
3153 if (R.getAsSingle<VarTemplateDecl>() &&
3154 !TemplateSpecializationType::anyDependentTemplateArguments(
3155 *TemplateArgs, InstantiationDependent)) {
3156 return CheckVarTemplateId(SS, R.getLookupNameInfo(),
3157 R.getAsSingle<VarTemplateDecl>(),
3158 TemplateKWLoc, TemplateArgs);
3161 // We don't want lookup warnings at this point.
3162 R.suppressDiagnostics();
3164 UnresolvedLookupExpr *ULE
3165 = UnresolvedLookupExpr::Create(Context, R.getNamingClass(),
3166 SS.getWithLocInContext(Context),
3168 R.getLookupNameInfo(),
3169 RequiresADL, TemplateArgs,
3170 R.begin(), R.end());
3175 // We actually only call this from template instantiation.
3177 Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS,
3178 SourceLocation TemplateKWLoc,
3179 const DeclarationNameInfo &NameInfo,
3180 const TemplateArgumentListInfo *TemplateArgs) {
3182 assert(TemplateArgs || TemplateKWLoc.isValid());
3184 if (!(DC = computeDeclContext(SS, false)) ||
3185 DC->isDependentContext() ||
3186 RequireCompleteDeclContext(SS, DC))
3187 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
3189 bool MemberOfUnknownSpecialization;
3190 LookupResult R(*this, NameInfo, LookupOrdinaryName);
3191 LookupTemplateName(R, (Scope*)nullptr, SS, QualType(), /*Entering*/ false,
3192 MemberOfUnknownSpecialization);
3194 if (R.isAmbiguous())
3198 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_non_template)
3199 << NameInfo.getName() << SS.getRange();
3203 if (ClassTemplateDecl *Temp = R.getAsSingle<ClassTemplateDecl>()) {
3204 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_class_template)
3206 << NameInfo.getName().getAsString() << SS.getRange();
3207 Diag(Temp->getLocation(), diag::note_referenced_class_template);
3211 return BuildTemplateIdExpr(SS, TemplateKWLoc, R, /*ADL*/ false, TemplateArgs);
3214 /// \brief Form a dependent template name.
3216 /// This action forms a dependent template name given the template
3217 /// name and its (presumably dependent) scope specifier. For
3218 /// example, given "MetaFun::template apply", the scope specifier \p
3219 /// SS will be "MetaFun::", \p TemplateKWLoc contains the location
3220 /// of the "template" keyword, and "apply" is the \p Name.
3221 TemplateNameKind Sema::ActOnDependentTemplateName(Scope *S,
3223 SourceLocation TemplateKWLoc,
3224 UnqualifiedId &Name,
3225 ParsedType ObjectType,
3226 bool EnteringContext,
3227 TemplateTy &Result) {
3228 if (TemplateKWLoc.isValid() && S && !S->getTemplateParamParent())
3230 getLangOpts().CPlusPlus11 ?
3231 diag::warn_cxx98_compat_template_outside_of_template :
3232 diag::ext_template_outside_of_template)
3233 << FixItHint::CreateRemoval(TemplateKWLoc);
3235 DeclContext *LookupCtx = nullptr;
3237 LookupCtx = computeDeclContext(SS, EnteringContext);
3238 if (!LookupCtx && ObjectType)
3239 LookupCtx = computeDeclContext(ObjectType.get());
3241 // C++0x [temp.names]p5:
3242 // If a name prefixed by the keyword template is not the name of
3243 // a template, the program is ill-formed. [Note: the keyword
3244 // template may not be applied to non-template members of class
3245 // templates. -end note ] [ Note: as is the case with the
3246 // typename prefix, the template prefix is allowed in cases
3247 // where it is not strictly necessary; i.e., when the
3248 // nested-name-specifier or the expression on the left of the ->
3249 // or . is not dependent on a template-parameter, or the use
3250 // does not appear in the scope of a template. -end note]
3252 // Note: C++03 was more strict here, because it banned the use of
3253 // the "template" keyword prior to a template-name that was not a
3254 // dependent name. C++ DR468 relaxed this requirement (the
3255 // "template" keyword is now permitted). We follow the C++0x
3256 // rules, even in C++03 mode with a warning, retroactively applying the DR.
3257 bool MemberOfUnknownSpecialization;
3258 TemplateNameKind TNK = isTemplateName(S, SS, TemplateKWLoc.isValid(), Name,
3259 ObjectType, EnteringContext, Result,
3260 MemberOfUnknownSpecialization);
3261 if (TNK == TNK_Non_template && LookupCtx->isDependentContext() &&
3262 isa<CXXRecordDecl>(LookupCtx) &&
3263 (!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() ||
3264 cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases())) {
3265 // This is a dependent template. Handle it below.
3266 } else if (TNK == TNK_Non_template) {
3267 Diag(Name.getLocStart(),
3268 diag::err_template_kw_refers_to_non_template)
3269 << GetNameFromUnqualifiedId(Name).getName()
3270 << Name.getSourceRange()
3272 return TNK_Non_template;
3274 // We found something; return it.
3279 NestedNameSpecifier *Qualifier = SS.getScopeRep();
3281 switch (Name.getKind()) {
3282 case UnqualifiedId::IK_Identifier:
3283 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier,
3285 return TNK_Dependent_template_name;
3287 case UnqualifiedId::IK_OperatorFunctionId:
3288 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier,
3289 Name.OperatorFunctionId.Operator));
3290 return TNK_Function_template;
3292 case UnqualifiedId::IK_LiteralOperatorId:
3293 llvm_unreachable("literal operator id cannot have a dependent scope");
3299 Diag(Name.getLocStart(),
3300 diag::err_template_kw_refers_to_non_template)
3301 << GetNameFromUnqualifiedId(Name).getName()
3302 << Name.getSourceRange()
3304 return TNK_Non_template;
3307 bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param,
3308 TemplateArgumentLoc &AL,
3309 SmallVectorImpl<TemplateArgument> &Converted) {
3310 const TemplateArgument &Arg = AL.getArgument();
3312 TypeSourceInfo *TSI = nullptr;
3314 // Check template type parameter.
3315 switch(Arg.getKind()) {
3316 case TemplateArgument::Type:
3317 // C++ [temp.arg.type]p1:
3318 // A template-argument for a template-parameter which is a
3319 // type shall be a type-id.
3320 ArgType = Arg.getAsType();
3321 TSI = AL.getTypeSourceInfo();
3323 case TemplateArgument::Template: {
3324 // We have a template type parameter but the template argument
3325 // is a template without any arguments.
3326 SourceRange SR = AL.getSourceRange();
3327 TemplateName Name = Arg.getAsTemplate();
3328 Diag(SR.getBegin(), diag::err_template_missing_args)
3330 if (TemplateDecl *Decl = Name.getAsTemplateDecl())
3331 Diag(Decl->getLocation(), diag::note_template_decl_here);
3335 case TemplateArgument::Expression: {
3336 // We have a template type parameter but the template argument is an
3337 // expression; see if maybe it is missing the "typename" keyword.
3339 DeclarationNameInfo NameInfo;
3341 if (DeclRefExpr *ArgExpr = dyn_cast<DeclRefExpr>(Arg.getAsExpr())) {
3342 SS.Adopt(ArgExpr->getQualifierLoc());
3343 NameInfo = ArgExpr->getNameInfo();
3344 } else if (DependentScopeDeclRefExpr *ArgExpr =
3345 dyn_cast<DependentScopeDeclRefExpr>(Arg.getAsExpr())) {
3346 SS.Adopt(ArgExpr->getQualifierLoc());
3347 NameInfo = ArgExpr->getNameInfo();
3348 } else if (CXXDependentScopeMemberExpr *ArgExpr =
3349 dyn_cast<CXXDependentScopeMemberExpr>(Arg.getAsExpr())) {
3350 if (ArgExpr->isImplicitAccess()) {
3351 SS.Adopt(ArgExpr->getQualifierLoc());
3352 NameInfo = ArgExpr->getMemberNameInfo();
3356 if (auto *II = NameInfo.getName().getAsIdentifierInfo()) {
3357 LookupResult Result(*this, NameInfo, LookupOrdinaryName);
3358 LookupParsedName(Result, CurScope, &SS);
3360 if (Result.getAsSingle<TypeDecl>() ||
3361 Result.getResultKind() ==
3362 LookupResult::NotFoundInCurrentInstantiation) {
3363 // Suggest that the user add 'typename' before the NNS.
3364 SourceLocation Loc = AL.getSourceRange().getBegin();
3365 Diag(Loc, getLangOpts().MSVCCompat
3366 ? diag::ext_ms_template_type_arg_missing_typename
3367 : diag::err_template_arg_must_be_type_suggest)
3368 << FixItHint::CreateInsertion(Loc, "typename ");
3369 Diag(Param->getLocation(), diag::note_template_param_here);
3371 // Recover by synthesizing a type using the location information that we
3374 Context.getDependentNameType(ETK_Typename, SS.getScopeRep(), II);
3376 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(ArgType);
3377 TL.setElaboratedKeywordLoc(SourceLocation(/*synthesized*/));
3378 TL.setQualifierLoc(SS.getWithLocInContext(Context));
3379 TL.setNameLoc(NameInfo.getLoc());
3380 TSI = TLB.getTypeSourceInfo(Context, ArgType);
3382 // Overwrite our input TemplateArgumentLoc so that we can recover
3384 AL = TemplateArgumentLoc(TemplateArgument(ArgType),
3385 TemplateArgumentLocInfo(TSI));
3393 // We have a template type parameter but the template argument
3395 SourceRange SR = AL.getSourceRange();
3396 Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR;
3397 Diag(Param->getLocation(), diag::note_template_param_here);
3403 if (CheckTemplateArgument(Param, TSI))
3406 // Add the converted template type argument.
3407 ArgType = Context.getCanonicalType(ArgType);
3410 // If an explicitly-specified template argument type is a lifetime type
3411 // with no lifetime qualifier, the __strong lifetime qualifier is inferred.
3412 if (getLangOpts().ObjCAutoRefCount &&
3413 ArgType->isObjCLifetimeType() &&
3414 !ArgType.getObjCLifetime()) {
3416 Qs.setObjCLifetime(Qualifiers::OCL_Strong);
3417 ArgType = Context.getQualifiedType(ArgType, Qs);
3420 Converted.push_back(TemplateArgument(ArgType));
3424 /// \brief Substitute template arguments into the default template argument for
3425 /// the given template type parameter.
3427 /// \param SemaRef the semantic analysis object for which we are performing
3428 /// the substitution.
3430 /// \param Template the template that we are synthesizing template arguments
3433 /// \param TemplateLoc the location of the template name that started the
3434 /// template-id we are checking.
3436 /// \param RAngleLoc the location of the right angle bracket ('>') that
3437 /// terminates the template-id.
3439 /// \param Param the template template parameter whose default we are
3440 /// substituting into.
3442 /// \param Converted the list of template arguments provided for template
3443 /// parameters that precede \p Param in the template parameter list.
3444 /// \returns the substituted template argument, or NULL if an error occurred.
3445 static TypeSourceInfo *
3446 SubstDefaultTemplateArgument(Sema &SemaRef,
3447 TemplateDecl *Template,
3448 SourceLocation TemplateLoc,
3449 SourceLocation RAngleLoc,
3450 TemplateTypeParmDecl *Param,
3451 SmallVectorImpl<TemplateArgument> &Converted) {
3452 TypeSourceInfo *ArgType = Param->getDefaultArgumentInfo();
3454 // If the argument type is dependent, instantiate it now based
3455 // on the previously-computed template arguments.
3456 if (ArgType->getType()->isDependentType()) {
3457 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
3458 Param, Template, Converted,
3459 SourceRange(TemplateLoc, RAngleLoc));
3460 if (Inst.isInvalid())
3463 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
3465 // Only substitute for the innermost template argument list.
3466 MultiLevelTemplateArgumentList TemplateArgLists;
3467 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3468 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3469 TemplateArgLists.addOuterTemplateArguments(None);
3471 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
3473 SemaRef.SubstType(ArgType, TemplateArgLists,
3474 Param->getDefaultArgumentLoc(), Param->getDeclName());
3480 /// \brief Substitute template arguments into the default template argument for
3481 /// the given non-type template parameter.
3483 /// \param SemaRef the semantic analysis object for which we are performing
3484 /// the substitution.
3486 /// \param Template the template that we are synthesizing template arguments
3489 /// \param TemplateLoc the location of the template name that started the
3490 /// template-id we are checking.
3492 /// \param RAngleLoc the location of the right angle bracket ('>') that
3493 /// terminates the template-id.
3495 /// \param Param the non-type template parameter whose default we are
3496 /// substituting into.
3498 /// \param Converted the list of template arguments provided for template
3499 /// parameters that precede \p Param in the template parameter list.
3501 /// \returns the substituted template argument, or NULL if an error occurred.
3503 SubstDefaultTemplateArgument(Sema &SemaRef,
3504 TemplateDecl *Template,
3505 SourceLocation TemplateLoc,
3506 SourceLocation RAngleLoc,
3507 NonTypeTemplateParmDecl *Param,
3508 SmallVectorImpl<TemplateArgument> &Converted) {
3509 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
3510 Param, Template, Converted,
3511 SourceRange(TemplateLoc, RAngleLoc));
3512 if (Inst.isInvalid())
3515 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
3517 // Only substitute for the innermost template argument list.
3518 MultiLevelTemplateArgumentList TemplateArgLists;
3519 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3520 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3521 TemplateArgLists.addOuterTemplateArguments(None);
3523 EnterExpressionEvaluationContext ConstantEvaluated(SemaRef,
3524 Sema::ConstantEvaluated);
3525 return SemaRef.SubstExpr(Param->getDefaultArgument(), TemplateArgLists);
3528 /// \brief Substitute template arguments into the default template argument for
3529 /// the given template template parameter.
3531 /// \param SemaRef the semantic analysis object for which we are performing
3532 /// the substitution.
3534 /// \param Template the template that we are synthesizing template arguments
3537 /// \param TemplateLoc the location of the template name that started the
3538 /// template-id we are checking.
3540 /// \param RAngleLoc the location of the right angle bracket ('>') that
3541 /// terminates the template-id.
3543 /// \param Param the template template parameter whose default we are
3544 /// substituting into.
3546 /// \param Converted the list of template arguments provided for template
3547 /// parameters that precede \p Param in the template parameter list.
3549 /// \param QualifierLoc Will be set to the nested-name-specifier (with
3550 /// source-location information) that precedes the template name.
3552 /// \returns the substituted template argument, or NULL if an error occurred.
3554 SubstDefaultTemplateArgument(Sema &SemaRef,
3555 TemplateDecl *Template,
3556 SourceLocation TemplateLoc,
3557 SourceLocation RAngleLoc,
3558 TemplateTemplateParmDecl *Param,
3559 SmallVectorImpl<TemplateArgument> &Converted,
3560 NestedNameSpecifierLoc &QualifierLoc) {
3561 Sema::InstantiatingTemplate Inst(
3562 SemaRef, TemplateLoc, TemplateParameter(Param), Template, Converted,
3563 SourceRange(TemplateLoc, RAngleLoc));
3564 if (Inst.isInvalid())
3565 return TemplateName();
3567 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
3569 // Only substitute for the innermost template argument list.
3570 MultiLevelTemplateArgumentList TemplateArgLists;
3571 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3572 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3573 TemplateArgLists.addOuterTemplateArguments(None);
3575 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
3576 // Substitute into the nested-name-specifier first,
3577 QualifierLoc = Param->getDefaultArgument().getTemplateQualifierLoc();
3580 SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgLists);
3582 return TemplateName();
3585 return SemaRef.SubstTemplateName(
3587 Param->getDefaultArgument().getArgument().getAsTemplate(),
3588 Param->getDefaultArgument().getTemplateNameLoc(),
3592 /// \brief If the given template parameter has a default template
3593 /// argument, substitute into that default template argument and
3594 /// return the corresponding template argument.
3596 Sema::SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template,
3597 SourceLocation TemplateLoc,
3598 SourceLocation RAngleLoc,
3600 SmallVectorImpl<TemplateArgument>
3602 bool &HasDefaultArg) {
3603 HasDefaultArg = false;
3605 if (TemplateTypeParmDecl *TypeParm = dyn_cast<TemplateTypeParmDecl>(Param)) {
3606 if (!hasVisibleDefaultArgument(TypeParm))
3607 return TemplateArgumentLoc();
3609 HasDefaultArg = true;
3610 TypeSourceInfo *DI = SubstDefaultTemplateArgument(*this, Template,
3616 return TemplateArgumentLoc(TemplateArgument(DI->getType()), DI);
3618 return TemplateArgumentLoc();
3621 if (NonTypeTemplateParmDecl *NonTypeParm
3622 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3623 if (!hasVisibleDefaultArgument(NonTypeParm))
3624 return TemplateArgumentLoc();
3626 HasDefaultArg = true;
3627 ExprResult Arg = SubstDefaultTemplateArgument(*this, Template,
3632 if (Arg.isInvalid())
3633 return TemplateArgumentLoc();
3635 Expr *ArgE = Arg.getAs<Expr>();
3636 return TemplateArgumentLoc(TemplateArgument(ArgE), ArgE);
3639 TemplateTemplateParmDecl *TempTempParm
3640 = cast<TemplateTemplateParmDecl>(Param);
3641 if (!hasVisibleDefaultArgument(TempTempParm))
3642 return TemplateArgumentLoc();
3644 HasDefaultArg = true;
3645 NestedNameSpecifierLoc QualifierLoc;
3646 TemplateName TName = SubstDefaultTemplateArgument(*this, Template,
3653 return TemplateArgumentLoc();
3655 return TemplateArgumentLoc(TemplateArgument(TName),
3656 TempTempParm->getDefaultArgument().getTemplateQualifierLoc(),
3657 TempTempParm->getDefaultArgument().getTemplateNameLoc());
3660 /// \brief Check that the given template argument corresponds to the given
3661 /// template parameter.
3663 /// \param Param The template parameter against which the argument will be
3666 /// \param Arg The template argument, which may be updated due to conversions.
3668 /// \param Template The template in which the template argument resides.
3670 /// \param TemplateLoc The location of the template name for the template
3671 /// whose argument list we're matching.
3673 /// \param RAngleLoc The location of the right angle bracket ('>') that closes
3674 /// the template argument list.
3676 /// \param ArgumentPackIndex The index into the argument pack where this
3677 /// argument will be placed. Only valid if the parameter is a parameter pack.
3679 /// \param Converted The checked, converted argument will be added to the
3680 /// end of this small vector.
3682 /// \param CTAK Describes how we arrived at this particular template argument:
3683 /// explicitly written, deduced, etc.
3685 /// \returns true on error, false otherwise.
3686 bool Sema::CheckTemplateArgument(NamedDecl *Param,
3687 TemplateArgumentLoc &Arg,
3688 NamedDecl *Template,
3689 SourceLocation TemplateLoc,
3690 SourceLocation RAngleLoc,
3691 unsigned ArgumentPackIndex,
3692 SmallVectorImpl<TemplateArgument> &Converted,
3693 CheckTemplateArgumentKind CTAK) {
3694 // Check template type parameters.
3695 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param))
3696 return CheckTemplateTypeArgument(TTP, Arg, Converted);
3698 // Check non-type template parameters.
3699 if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3700 // Do substitution on the type of the non-type template parameter
3701 // with the template arguments we've seen thus far. But if the
3702 // template has a dependent context then we cannot substitute yet.
3703 QualType NTTPType = NTTP->getType();
3704 if (NTTP->isParameterPack() && NTTP->isExpandedParameterPack())
3705 NTTPType = NTTP->getExpansionType(ArgumentPackIndex);
3707 if (NTTPType->isDependentType() &&
3708 !isa<TemplateTemplateParmDecl>(Template) &&
3709 !Template->getDeclContext()->isDependentContext()) {
3710 // Do substitution on the type of the non-type template parameter.
3711 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
3713 SourceRange(TemplateLoc, RAngleLoc));
3714 if (Inst.isInvalid())
3717 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
3719 NTTPType = SubstType(NTTPType,
3720 MultiLevelTemplateArgumentList(TemplateArgs),
3721 NTTP->getLocation(),
3722 NTTP->getDeclName());
3723 // If that worked, check the non-type template parameter type
3725 if (!NTTPType.isNull())
3726 NTTPType = CheckNonTypeTemplateParameterType(NTTPType,
3727 NTTP->getLocation());
3728 if (NTTPType.isNull())
3732 switch (Arg.getArgument().getKind()) {
3733 case TemplateArgument::Null:
3734 llvm_unreachable("Should never see a NULL template argument here");
3736 case TemplateArgument::Expression: {
3737 TemplateArgument Result;
3739 CheckTemplateArgument(NTTP, NTTPType, Arg.getArgument().getAsExpr(),
3741 if (Res.isInvalid())
3744 // If the resulting expression is new, then use it in place of the
3745 // old expression in the template argument.
3746 if (Res.get() != Arg.getArgument().getAsExpr()) {
3747 TemplateArgument TA(Res.get());
3748 Arg = TemplateArgumentLoc(TA, Res.get());
3751 Converted.push_back(Result);
3755 case TemplateArgument::Declaration:
3756 case TemplateArgument::Integral:
3757 case TemplateArgument::NullPtr:
3758 // We've already checked this template argument, so just copy
3759 // it to the list of converted arguments.
3760 Converted.push_back(Arg.getArgument());
3763 case TemplateArgument::Template:
3764 case TemplateArgument::TemplateExpansion:
3765 // We were given a template template argument. It may not be ill-formed;
3767 if (DependentTemplateName *DTN
3768 = Arg.getArgument().getAsTemplateOrTemplatePattern()
3769 .getAsDependentTemplateName()) {
3770 // We have a template argument such as \c T::template X, which we
3771 // parsed as a template template argument. However, since we now
3772 // know that we need a non-type template argument, convert this
3773 // template name into an expression.
3775 DeclarationNameInfo NameInfo(DTN->getIdentifier(),
3776 Arg.getTemplateNameLoc());
3779 SS.Adopt(Arg.getTemplateQualifierLoc());
3780 // FIXME: the template-template arg was a DependentTemplateName,
3781 // so it was provided with a template keyword. However, its source
3782 // location is not stored in the template argument structure.
3783 SourceLocation TemplateKWLoc;
3784 ExprResult E = DependentScopeDeclRefExpr::Create(
3785 Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo,
3788 // If we parsed the template argument as a pack expansion, create a
3789 // pack expansion expression.
3790 if (Arg.getArgument().getKind() == TemplateArgument::TemplateExpansion){
3791 E = ActOnPackExpansion(E.get(), Arg.getTemplateEllipsisLoc());
3796 TemplateArgument Result;
3797 E = CheckTemplateArgument(NTTP, NTTPType, E.get(), Result);
3801 Converted.push_back(Result);
3805 // We have a template argument that actually does refer to a class
3806 // template, alias template, or template template parameter, and
3807 // therefore cannot be a non-type template argument.
3808 Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr)
3809 << Arg.getSourceRange();
3811 Diag(Param->getLocation(), diag::note_template_param_here);
3814 case TemplateArgument::Type: {
3815 // We have a non-type template parameter but the template
3816 // argument is a type.
3818 // C++ [temp.arg]p2:
3819 // In a template-argument, an ambiguity between a type-id and
3820 // an expression is resolved to a type-id, regardless of the
3821 // form of the corresponding template-parameter.
3823 // We warn specifically about this case, since it can be rather
3824 // confusing for users.
3825 QualType T = Arg.getArgument().getAsType();
3826 SourceRange SR = Arg.getSourceRange();
3827 if (T->isFunctionType())
3828 Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T;
3830 Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR;
3831 Diag(Param->getLocation(), diag::note_template_param_here);
3835 case TemplateArgument::Pack:
3836 llvm_unreachable("Caller must expand template argument packs");
3843 // Check template template parameters.
3844 TemplateTemplateParmDecl *TempParm = cast<TemplateTemplateParmDecl>(Param);
3846 // Substitute into the template parameter list of the template
3847 // template parameter, since previously-supplied template arguments
3848 // may appear within the template template parameter.
3850 // Set up a template instantiation context.
3851 LocalInstantiationScope Scope(*this);
3852 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
3853 TempParm, Converted,
3854 SourceRange(TemplateLoc, RAngleLoc));
3855 if (Inst.isInvalid())
3858 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
3859 TempParm = cast_or_null<TemplateTemplateParmDecl>(
3860 SubstDecl(TempParm, CurContext,
3861 MultiLevelTemplateArgumentList(TemplateArgs)));
3866 switch (Arg.getArgument().getKind()) {
3867 case TemplateArgument::Null:
3868 llvm_unreachable("Should never see a NULL template argument here");
3870 case TemplateArgument::Template:
3871 case TemplateArgument::TemplateExpansion:
3872 if (CheckTemplateArgument(TempParm, Arg, ArgumentPackIndex))
3875 Converted.push_back(Arg.getArgument());
3878 case TemplateArgument::Expression:
3879 case TemplateArgument::Type:
3880 // We have a template template parameter but the template
3881 // argument does not refer to a template.
3882 Diag(Arg.getLocation(), diag::err_template_arg_must_be_template)
3883 << getLangOpts().CPlusPlus11;
3886 case TemplateArgument::Declaration:
3887 llvm_unreachable("Declaration argument with template template parameter");
3888 case TemplateArgument::Integral:
3889 llvm_unreachable("Integral argument with template template parameter");
3890 case TemplateArgument::NullPtr:
3891 llvm_unreachable("Null pointer argument with template template parameter");
3893 case TemplateArgument::Pack:
3894 llvm_unreachable("Caller must expand template argument packs");
3900 /// \brief Diagnose an arity mismatch in the
3901 static bool diagnoseArityMismatch(Sema &S, TemplateDecl *Template,
3902 SourceLocation TemplateLoc,
3903 TemplateArgumentListInfo &TemplateArgs) {
3904 TemplateParameterList *Params = Template->getTemplateParameters();
3905 unsigned NumParams = Params->size();
3906 unsigned NumArgs = TemplateArgs.size();
3909 if (NumArgs > NumParams)
3910 Range = SourceRange(TemplateArgs[NumParams].getLocation(),
3911 TemplateArgs.getRAngleLoc());
3912 S.Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
3913 << (NumArgs > NumParams)
3914 << (isa<ClassTemplateDecl>(Template)? 0 :
3915 isa<FunctionTemplateDecl>(Template)? 1 :
3916 isa<TemplateTemplateParmDecl>(Template)? 2 : 3)
3917 << Template << Range;
3918 S.Diag(Template->getLocation(), diag::note_template_decl_here)
3919 << Params->getSourceRange();
3923 /// \brief Check whether the template parameter is a pack expansion, and if so,
3924 /// determine the number of parameters produced by that expansion. For instance:
3927 /// template<typename ...Ts> struct A {
3928 /// template<Ts ...NTs, template<Ts> class ...TTs, typename ...Us> struct B;
3932 /// In \c A<int,int>::B, \c NTs and \c TTs have expanded pack size 2, and \c Us
3933 /// is not a pack expansion, so returns an empty Optional.
3934 static Optional<unsigned> getExpandedPackSize(NamedDecl *Param) {
3935 if (NonTypeTemplateParmDecl *NTTP
3936 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3937 if (NTTP->isExpandedParameterPack())
3938 return NTTP->getNumExpansionTypes();
3941 if (TemplateTemplateParmDecl *TTP
3942 = dyn_cast<TemplateTemplateParmDecl>(Param)) {
3943 if (TTP->isExpandedParameterPack())
3944 return TTP->getNumExpansionTemplateParameters();
3950 /// Diagnose a missing template argument.
3951 template<typename TemplateParmDecl>
3952 static bool diagnoseMissingArgument(Sema &S, SourceLocation Loc,
3954 const TemplateParmDecl *D,
3955 TemplateArgumentListInfo &Args) {
3956 // Dig out the most recent declaration of the template parameter; there may be
3957 // declarations of the template that are more recent than TD.
3958 D = cast<TemplateParmDecl>(cast<TemplateDecl>(TD->getMostRecentDecl())
3959 ->getTemplateParameters()
3960 ->getParam(D->getIndex()));
3962 // If there's a default argument that's not visible, diagnose that we're
3963 // missing a module import.
3964 llvm::SmallVector<Module*, 8> Modules;
3965 if (D->hasDefaultArgument() && !S.hasVisibleDefaultArgument(D, &Modules)) {
3966 S.diagnoseMissingImport(Loc, cast<NamedDecl>(TD),
3967 D->getDefaultArgumentLoc(), Modules,
3968 Sema::MissingImportKind::DefaultArgument,
3973 // FIXME: If there's a more recent default argument that *is* visible,
3974 // diagnose that it was declared too late.
3976 return diagnoseArityMismatch(S, TD, Loc, Args);
3979 /// \brief Check that the given template argument list is well-formed
3980 /// for specializing the given template.
3981 bool Sema::CheckTemplateArgumentList(TemplateDecl *Template,
3982 SourceLocation TemplateLoc,
3983 TemplateArgumentListInfo &TemplateArgs,
3984 bool PartialTemplateArgs,
3985 SmallVectorImpl<TemplateArgument> &Converted) {
3986 // Make a copy of the template arguments for processing. Only make the
3987 // changes at the end when successful in matching the arguments to the
3989 TemplateArgumentListInfo NewArgs = TemplateArgs;
3991 TemplateParameterList *Params = Template->getTemplateParameters();
3993 SourceLocation RAngleLoc = NewArgs.getRAngleLoc();
3995 // C++ [temp.arg]p1:
3996 // [...] The type and form of each template-argument specified in
3997 // a template-id shall match the type and form specified for the
3998 // corresponding parameter declared by the template in its
3999 // template-parameter-list.
4000 bool isTemplateTemplateParameter = isa<TemplateTemplateParmDecl>(Template);
4001 SmallVector<TemplateArgument, 2> ArgumentPack;
4002 unsigned ArgIdx = 0, NumArgs = NewArgs.size();
4003 LocalInstantiationScope InstScope(*this, true);
4004 for (TemplateParameterList::iterator Param = Params->begin(),
4005 ParamEnd = Params->end();
4006 Param != ParamEnd; /* increment in loop */) {
4007 // If we have an expanded parameter pack, make sure we don't have too
4009 if (Optional<unsigned> Expansions = getExpandedPackSize(*Param)) {
4010 if (*Expansions == ArgumentPack.size()) {
4011 // We're done with this parameter pack. Pack up its arguments and add
4012 // them to the list.
4013 Converted.push_back(
4014 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
4015 ArgumentPack.clear();
4017 // This argument is assigned to the next parameter.
4020 } else if (ArgIdx == NumArgs && !PartialTemplateArgs) {
4021 // Not enough arguments for this parameter pack.
4022 Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
4024 << (isa<ClassTemplateDecl>(Template)? 0 :
4025 isa<FunctionTemplateDecl>(Template)? 1 :
4026 isa<TemplateTemplateParmDecl>(Template)? 2 : 3)
4028 Diag(Template->getLocation(), diag::note_template_decl_here)
4029 << Params->getSourceRange();
4034 if (ArgIdx < NumArgs) {
4035 // Check the template argument we were given.
4036 if (CheckTemplateArgument(*Param, NewArgs[ArgIdx], Template,
4037 TemplateLoc, RAngleLoc,
4038 ArgumentPack.size(), Converted))
4041 bool PackExpansionIntoNonPack =
4042 NewArgs[ArgIdx].getArgument().isPackExpansion() &&
4043 (!(*Param)->isTemplateParameterPack() || getExpandedPackSize(*Param));
4044 if (PackExpansionIntoNonPack && isa<TypeAliasTemplateDecl>(Template)) {
4045 // Core issue 1430: we have a pack expansion as an argument to an
4046 // alias template, and it's not part of a parameter pack. This
4047 // can't be canonicalized, so reject it now.
4048 Diag(NewArgs[ArgIdx].getLocation(),
4049 diag::err_alias_template_expansion_into_fixed_list)
4050 << NewArgs[ArgIdx].getSourceRange();
4051 Diag((*Param)->getLocation(), diag::note_template_param_here);
4055 // We're now done with this argument.
4058 if ((*Param)->isTemplateParameterPack()) {
4059 // The template parameter was a template parameter pack, so take the
4060 // deduced argument and place it on the argument pack. Note that we
4061 // stay on the same template parameter so that we can deduce more
4063 ArgumentPack.push_back(Converted.pop_back_val());
4065 // Move to the next template parameter.
4069 // If we just saw a pack expansion into a non-pack, then directly convert
4070 // the remaining arguments, because we don't know what parameters they'll
4072 if (PackExpansionIntoNonPack) {
4073 if (!ArgumentPack.empty()) {
4074 // If we were part way through filling in an expanded parameter pack,
4075 // fall back to just producing individual arguments.
4076 Converted.insert(Converted.end(),
4077 ArgumentPack.begin(), ArgumentPack.end());
4078 ArgumentPack.clear();
4081 while (ArgIdx < NumArgs) {
4082 Converted.push_back(NewArgs[ArgIdx].getArgument());
4092 // If we're checking a partial template argument list, we're done.
4093 if (PartialTemplateArgs) {
4094 if ((*Param)->isTemplateParameterPack() && !ArgumentPack.empty())
4095 Converted.push_back(
4096 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
4101 // If we have a template parameter pack with no more corresponding
4102 // arguments, just break out now and we'll fill in the argument pack below.
4103 if ((*Param)->isTemplateParameterPack()) {
4104 assert(!getExpandedPackSize(*Param) &&
4105 "Should have dealt with this already");
4107 // A non-expanded parameter pack before the end of the parameter list
4108 // only occurs for an ill-formed template parameter list, unless we've
4109 // got a partial argument list for a function template, so just bail out.
4110 if (Param + 1 != ParamEnd)
4113 Converted.push_back(
4114 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
4115 ArgumentPack.clear();
4121 // Check whether we have a default argument.
4122 TemplateArgumentLoc Arg;
4124 // Retrieve the default template argument from the template
4125 // parameter. For each kind of template parameter, we substitute the
4126 // template arguments provided thus far and any "outer" template arguments
4127 // (when the template parameter was part of a nested template) into
4128 // the default argument.
4129 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*Param)) {
4130 if (!hasVisibleDefaultArgument(TTP))
4131 return diagnoseMissingArgument(*this, TemplateLoc, Template, TTP,
4134 TypeSourceInfo *ArgType = SubstDefaultTemplateArgument(*this,
4143 Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()),
4145 } else if (NonTypeTemplateParmDecl *NTTP
4146 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) {
4147 if (!hasVisibleDefaultArgument(NTTP))
4148 return diagnoseMissingArgument(*this, TemplateLoc, Template, NTTP,
4151 ExprResult E = SubstDefaultTemplateArgument(*this, Template,
4159 Expr *Ex = E.getAs<Expr>();
4160 Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex);
4162 TemplateTemplateParmDecl *TempParm
4163 = cast<TemplateTemplateParmDecl>(*Param);
4165 if (!hasVisibleDefaultArgument(TempParm))
4166 return diagnoseMissingArgument(*this, TemplateLoc, Template, TempParm,
4169 NestedNameSpecifierLoc QualifierLoc;
4170 TemplateName Name = SubstDefaultTemplateArgument(*this, Template,
4179 Arg = TemplateArgumentLoc(TemplateArgument(Name), QualifierLoc,
4180 TempParm->getDefaultArgument().getTemplateNameLoc());
4183 // Introduce an instantiation record that describes where we are using
4184 // the default template argument. We're not actually instantiating a
4185 // template here, we just create this object to put a note into the
4187 InstantiatingTemplate Inst(*this, RAngleLoc, Template, *Param, Converted,
4188 SourceRange(TemplateLoc, RAngleLoc));
4189 if (Inst.isInvalid())
4192 // Check the default template argument.
4193 if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc,
4194 RAngleLoc, 0, Converted))
4197 // Core issue 150 (assumed resolution): if this is a template template
4198 // parameter, keep track of the default template arguments from the
4199 // template definition.
4200 if (isTemplateTemplateParameter)
4201 NewArgs.addArgument(Arg);
4203 // Move to the next template parameter and argument.
4208 // If we're performing a partial argument substitution, allow any trailing
4209 // pack expansions; they might be empty. This can happen even if
4210 // PartialTemplateArgs is false (the list of arguments is complete but
4211 // still dependent).
4212 if (ArgIdx < NumArgs && CurrentInstantiationScope &&
4213 CurrentInstantiationScope->getPartiallySubstitutedPack()) {
4214 while (ArgIdx < NumArgs && NewArgs[ArgIdx].getArgument().isPackExpansion())
4215 Converted.push_back(NewArgs[ArgIdx++].getArgument());
4218 // If we have any leftover arguments, then there were too many arguments.
4219 // Complain and fail.
4220 if (ArgIdx < NumArgs)
4221 return diagnoseArityMismatch(*this, Template, TemplateLoc, NewArgs);
4223 // No problems found with the new argument list, propagate changes back
4225 TemplateArgs = std::move(NewArgs);
4231 class UnnamedLocalNoLinkageFinder
4232 : public TypeVisitor<UnnamedLocalNoLinkageFinder, bool>
4237 typedef TypeVisitor<UnnamedLocalNoLinkageFinder, bool> inherited;
4240 UnnamedLocalNoLinkageFinder(Sema &S, SourceRange SR) : S(S), SR(SR) { }
4242 bool Visit(QualType T) {
4243 return T.isNull() ? false : inherited::Visit(T.getTypePtr());
4246 #define TYPE(Class, Parent) \
4247 bool Visit##Class##Type(const Class##Type *);
4248 #define ABSTRACT_TYPE(Class, Parent) \
4249 bool Visit##Class##Type(const Class##Type *) { return false; }
4250 #define NON_CANONICAL_TYPE(Class, Parent) \
4251 bool Visit##Class##Type(const Class##Type *) { return false; }
4252 #include "clang/AST/TypeNodes.def"
4254 bool VisitTagDecl(const TagDecl *Tag);
4255 bool VisitNestedNameSpecifier(NestedNameSpecifier *NNS);
4257 } // end anonymous namespace
4259 bool UnnamedLocalNoLinkageFinder::VisitBuiltinType(const BuiltinType*) {
4263 bool UnnamedLocalNoLinkageFinder::VisitComplexType(const ComplexType* T) {
4264 return Visit(T->getElementType());
4267 bool UnnamedLocalNoLinkageFinder::VisitPointerType(const PointerType* T) {
4268 return Visit(T->getPointeeType());
4271 bool UnnamedLocalNoLinkageFinder::VisitBlockPointerType(
4272 const BlockPointerType* T) {
4273 return Visit(T->getPointeeType());
4276 bool UnnamedLocalNoLinkageFinder::VisitLValueReferenceType(
4277 const LValueReferenceType* T) {
4278 return Visit(T->getPointeeType());
4281 bool UnnamedLocalNoLinkageFinder::VisitRValueReferenceType(
4282 const RValueReferenceType* T) {
4283 return Visit(T->getPointeeType());
4286 bool UnnamedLocalNoLinkageFinder::VisitMemberPointerType(
4287 const MemberPointerType* T) {
4288 return Visit(T->getPointeeType()) || Visit(QualType(T->getClass(), 0));
4291 bool UnnamedLocalNoLinkageFinder::VisitConstantArrayType(
4292 const ConstantArrayType* T) {
4293 return Visit(T->getElementType());
4296 bool UnnamedLocalNoLinkageFinder::VisitIncompleteArrayType(
4297 const IncompleteArrayType* T) {
4298 return Visit(T->getElementType());
4301 bool UnnamedLocalNoLinkageFinder::VisitVariableArrayType(
4302 const VariableArrayType* T) {
4303 return Visit(T->getElementType());
4306 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedArrayType(
4307 const DependentSizedArrayType* T) {
4308 return Visit(T->getElementType());
4311 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedExtVectorType(
4312 const DependentSizedExtVectorType* T) {
4313 return Visit(T->getElementType());
4316 bool UnnamedLocalNoLinkageFinder::VisitVectorType(const VectorType* T) {
4317 return Visit(T->getElementType());
4320 bool UnnamedLocalNoLinkageFinder::VisitExtVectorType(const ExtVectorType* T) {
4321 return Visit(T->getElementType());
4324 bool UnnamedLocalNoLinkageFinder::VisitFunctionProtoType(
4325 const FunctionProtoType* T) {
4326 for (const auto &A : T->param_types()) {
4331 return Visit(T->getReturnType());
4334 bool UnnamedLocalNoLinkageFinder::VisitFunctionNoProtoType(
4335 const FunctionNoProtoType* T) {
4336 return Visit(T->getReturnType());
4339 bool UnnamedLocalNoLinkageFinder::VisitUnresolvedUsingType(
4340 const UnresolvedUsingType*) {
4344 bool UnnamedLocalNoLinkageFinder::VisitTypeOfExprType(const TypeOfExprType*) {
4348 bool UnnamedLocalNoLinkageFinder::VisitTypeOfType(const TypeOfType* T) {
4349 return Visit(T->getUnderlyingType());
4352 bool UnnamedLocalNoLinkageFinder::VisitDecltypeType(const DecltypeType*) {
4356 bool UnnamedLocalNoLinkageFinder::VisitUnaryTransformType(
4357 const UnaryTransformType*) {
4361 bool UnnamedLocalNoLinkageFinder::VisitAutoType(const AutoType *T) {
4362 return Visit(T->getDeducedType());
4365 bool UnnamedLocalNoLinkageFinder::VisitRecordType(const RecordType* T) {
4366 return VisitTagDecl(T->getDecl());
4369 bool UnnamedLocalNoLinkageFinder::VisitEnumType(const EnumType* T) {
4370 return VisitTagDecl(T->getDecl());
4373 bool UnnamedLocalNoLinkageFinder::VisitTemplateTypeParmType(
4374 const TemplateTypeParmType*) {
4378 bool UnnamedLocalNoLinkageFinder::VisitSubstTemplateTypeParmPackType(
4379 const SubstTemplateTypeParmPackType *) {
4383 bool UnnamedLocalNoLinkageFinder::VisitTemplateSpecializationType(
4384 const TemplateSpecializationType*) {
4388 bool UnnamedLocalNoLinkageFinder::VisitInjectedClassNameType(
4389 const InjectedClassNameType* T) {
4390 return VisitTagDecl(T->getDecl());
4393 bool UnnamedLocalNoLinkageFinder::VisitDependentNameType(
4394 const DependentNameType* T) {
4395 return VisitNestedNameSpecifier(T->getQualifier());
4398 bool UnnamedLocalNoLinkageFinder::VisitDependentTemplateSpecializationType(
4399 const DependentTemplateSpecializationType* T) {
4400 return VisitNestedNameSpecifier(T->getQualifier());
4403 bool UnnamedLocalNoLinkageFinder::VisitPackExpansionType(
4404 const PackExpansionType* T) {
4405 return Visit(T->getPattern());
4408 bool UnnamedLocalNoLinkageFinder::VisitObjCObjectType(const ObjCObjectType *) {
4412 bool UnnamedLocalNoLinkageFinder::VisitObjCInterfaceType(
4413 const ObjCInterfaceType *) {
4417 bool UnnamedLocalNoLinkageFinder::VisitObjCObjectPointerType(
4418 const ObjCObjectPointerType *) {
4422 bool UnnamedLocalNoLinkageFinder::VisitAtomicType(const AtomicType* T) {
4423 return Visit(T->getValueType());
4426 bool UnnamedLocalNoLinkageFinder::VisitPipeType(const PipeType* T) {
4430 bool UnnamedLocalNoLinkageFinder::VisitTagDecl(const TagDecl *Tag) {
4431 if (Tag->getDeclContext()->isFunctionOrMethod()) {
4432 S.Diag(SR.getBegin(),
4433 S.getLangOpts().CPlusPlus11 ?
4434 diag::warn_cxx98_compat_template_arg_local_type :
4435 diag::ext_template_arg_local_type)
4436 << S.Context.getTypeDeclType(Tag) << SR;
4440 if (!Tag->hasNameForLinkage()) {
4441 S.Diag(SR.getBegin(),
4442 S.getLangOpts().CPlusPlus11 ?
4443 diag::warn_cxx98_compat_template_arg_unnamed_type :
4444 diag::ext_template_arg_unnamed_type) << SR;
4445 S.Diag(Tag->getLocation(), diag::note_template_unnamed_type_here);
4452 bool UnnamedLocalNoLinkageFinder::VisitNestedNameSpecifier(
4453 NestedNameSpecifier *NNS) {
4454 if (NNS->getPrefix() && VisitNestedNameSpecifier(NNS->getPrefix()))
4457 switch (NNS->getKind()) {
4458 case NestedNameSpecifier::Identifier:
4459 case NestedNameSpecifier::Namespace:
4460 case NestedNameSpecifier::NamespaceAlias:
4461 case NestedNameSpecifier::Global:
4462 case NestedNameSpecifier::Super:
4465 case NestedNameSpecifier::TypeSpec:
4466 case NestedNameSpecifier::TypeSpecWithTemplate:
4467 return Visit(QualType(NNS->getAsType(), 0));
4469 llvm_unreachable("Invalid NestedNameSpecifier::Kind!");
4472 /// \brief Check a template argument against its corresponding
4473 /// template type parameter.
4475 /// This routine implements the semantics of C++ [temp.arg.type]. It
4476 /// returns true if an error occurred, and false otherwise.
4477 bool Sema::CheckTemplateArgument(TemplateTypeParmDecl *Param,
4478 TypeSourceInfo *ArgInfo) {
4479 assert(ArgInfo && "invalid TypeSourceInfo");
4480 QualType Arg = ArgInfo->getType();
4481 SourceRange SR = ArgInfo->getTypeLoc().getSourceRange();
4483 if (Arg->isVariablyModifiedType()) {
4484 return Diag(SR.getBegin(), diag::err_variably_modified_template_arg) << Arg;
4485 } else if (Context.hasSameUnqualifiedType(Arg, Context.OverloadTy)) {
4486 return Diag(SR.getBegin(), diag::err_template_arg_overload_type) << SR;
4489 // C++03 [temp.arg.type]p2:
4490 // A local type, a type with no linkage, an unnamed type or a type
4491 // compounded from any of these types shall not be used as a
4492 // template-argument for a template type-parameter.
4494 // C++11 allows these, and even in C++03 we allow them as an extension with
4496 if (LangOpts.CPlusPlus11 || Arg->hasUnnamedOrLocalType()) {
4497 UnnamedLocalNoLinkageFinder Finder(*this, SR);
4498 (void)Finder.Visit(Context.getCanonicalType(Arg));
4504 enum NullPointerValueKind {
4510 /// \brief Determine whether the given template argument is a null pointer
4511 /// value of the appropriate type.
4512 static NullPointerValueKind
4513 isNullPointerValueTemplateArgument(Sema &S, NonTypeTemplateParmDecl *Param,
4514 QualType ParamType, Expr *Arg) {
4515 if (Arg->isValueDependent() || Arg->isTypeDependent())
4516 return NPV_NotNullPointer;
4518 if (!S.isCompleteType(Arg->getExprLoc(), ParamType))
4520 "Incomplete parameter type in isNullPointerValueTemplateArgument!");
4522 if (!S.getLangOpts().CPlusPlus11)
4523 return NPV_NotNullPointer;
4525 // Determine whether we have a constant expression.
4526 ExprResult ArgRV = S.DefaultFunctionArrayConversion(Arg);
4527 if (ArgRV.isInvalid())
4531 Expr::EvalResult EvalResult;
4532 SmallVector<PartialDiagnosticAt, 8> Notes;
4533 EvalResult.Diag = &Notes;
4534 if (!Arg->EvaluateAsRValue(EvalResult, S.Context) ||
4535 EvalResult.HasSideEffects) {
4536 SourceLocation DiagLoc = Arg->getExprLoc();
4538 // If our only note is the usual "invalid subexpression" note, just point
4539 // the caret at its location rather than producing an essentially
4541 if (Notes.size() == 1 && Notes[0].second.getDiagID() ==
4542 diag::note_invalid_subexpr_in_const_expr) {
4543 DiagLoc = Notes[0].first;
4547 S.Diag(DiagLoc, diag::err_template_arg_not_address_constant)
4548 << Arg->getType() << Arg->getSourceRange();
4549 for (unsigned I = 0, N = Notes.size(); I != N; ++I)
4550 S.Diag(Notes[I].first, Notes[I].second);
4552 S.Diag(Param->getLocation(), diag::note_template_param_here);
4556 // C++11 [temp.arg.nontype]p1:
4557 // - an address constant expression of type std::nullptr_t
4558 if (Arg->getType()->isNullPtrType())
4559 return NPV_NullPointer;
4561 // - a constant expression that evaluates to a null pointer value (4.10); or
4562 // - a constant expression that evaluates to a null member pointer value
4564 if ((EvalResult.Val.isLValue() && !EvalResult.Val.getLValueBase()) ||
4565 (EvalResult.Val.isMemberPointer() &&
4566 !EvalResult.Val.getMemberPointerDecl())) {
4567 // If our expression has an appropriate type, we've succeeded.
4568 bool ObjCLifetimeConversion;
4569 if (S.Context.hasSameUnqualifiedType(Arg->getType(), ParamType) ||
4570 S.IsQualificationConversion(Arg->getType(), ParamType, false,
4571 ObjCLifetimeConversion))
4572 return NPV_NullPointer;
4574 // The types didn't match, but we know we got a null pointer; complain,
4575 // then recover as if the types were correct.
4576 S.Diag(Arg->getExprLoc(), diag::err_template_arg_wrongtype_null_constant)
4577 << Arg->getType() << ParamType << Arg->getSourceRange();
4578 S.Diag(Param->getLocation(), diag::note_template_param_here);
4579 return NPV_NullPointer;
4582 // If we don't have a null pointer value, but we do have a NULL pointer
4583 // constant, suggest a cast to the appropriate type.
4584 if (Arg->isNullPointerConstant(S.Context, Expr::NPC_NeverValueDependent)) {
4585 std::string Code = "static_cast<" + ParamType.getAsString() + ">(";
4586 S.Diag(Arg->getExprLoc(), diag::err_template_arg_untyped_null_constant)
4587 << ParamType << FixItHint::CreateInsertion(Arg->getLocStart(), Code)
4588 << FixItHint::CreateInsertion(S.getLocForEndOfToken(Arg->getLocEnd()),
4590 S.Diag(Param->getLocation(), diag::note_template_param_here);
4591 return NPV_NullPointer;
4594 // FIXME: If we ever want to support general, address-constant expressions
4595 // as non-type template arguments, we should return the ExprResult here to
4596 // be interpreted by the caller.
4597 return NPV_NotNullPointer;
4600 /// \brief Checks whether the given template argument is compatible with its
4601 /// template parameter.
4602 static bool CheckTemplateArgumentIsCompatibleWithParameter(
4603 Sema &S, NonTypeTemplateParmDecl *Param, QualType ParamType, Expr *ArgIn,
4604 Expr *Arg, QualType ArgType) {
4605 bool ObjCLifetimeConversion;
4606 if (ParamType->isPointerType() &&
4607 !ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType() &&
4608 S.IsQualificationConversion(ArgType, ParamType, false,
4609 ObjCLifetimeConversion)) {
4610 // For pointer-to-object types, qualification conversions are
4613 if (const ReferenceType *ParamRef = ParamType->getAs<ReferenceType>()) {
4614 if (!ParamRef->getPointeeType()->isFunctionType()) {
4615 // C++ [temp.arg.nontype]p5b3:
4616 // For a non-type template-parameter of type reference to
4617 // object, no conversions apply. The type referred to by the
4618 // reference may be more cv-qualified than the (otherwise
4619 // identical) type of the template- argument. The
4620 // template-parameter is bound directly to the
4621 // template-argument, which shall be an lvalue.
4623 // FIXME: Other qualifiers?
4624 unsigned ParamQuals = ParamRef->getPointeeType().getCVRQualifiers();
4625 unsigned ArgQuals = ArgType.getCVRQualifiers();
4627 if ((ParamQuals | ArgQuals) != ParamQuals) {
4628 S.Diag(Arg->getLocStart(),
4629 diag::err_template_arg_ref_bind_ignores_quals)
4630 << ParamType << Arg->getType() << Arg->getSourceRange();
4631 S.Diag(Param->getLocation(), diag::note_template_param_here);
4637 // At this point, the template argument refers to an object or
4638 // function with external linkage. We now need to check whether the
4639 // argument and parameter types are compatible.
4640 if (!S.Context.hasSameUnqualifiedType(ArgType,
4641 ParamType.getNonReferenceType())) {
4642 // We can't perform this conversion or binding.
4643 if (ParamType->isReferenceType())
4644 S.Diag(Arg->getLocStart(), diag::err_template_arg_no_ref_bind)
4645 << ParamType << ArgIn->getType() << Arg->getSourceRange();
4647 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible)
4648 << ArgIn->getType() << ParamType << Arg->getSourceRange();
4649 S.Diag(Param->getLocation(), diag::note_template_param_here);
4657 /// \brief Checks whether the given template argument is the address
4658 /// of an object or function according to C++ [temp.arg.nontype]p1.
4660 CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S,
4661 NonTypeTemplateParmDecl *Param,
4664 TemplateArgument &Converted) {
4665 bool Invalid = false;
4667 QualType ArgType = Arg->getType();
4669 bool AddressTaken = false;
4670 SourceLocation AddrOpLoc;
4671 if (S.getLangOpts().MicrosoftExt) {
4672 // Microsoft Visual C++ strips all casts, allows an arbitrary number of
4673 // dereference and address-of operators.
4674 Arg = Arg->IgnoreParenCasts();
4676 bool ExtWarnMSTemplateArg = false;
4677 UnaryOperatorKind FirstOpKind;
4678 SourceLocation FirstOpLoc;
4679 while (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
4680 UnaryOperatorKind UnOpKind = UnOp->getOpcode();
4681 if (UnOpKind == UO_Deref)
4682 ExtWarnMSTemplateArg = true;
4683 if (UnOpKind == UO_AddrOf || UnOpKind == UO_Deref) {
4684 Arg = UnOp->getSubExpr()->IgnoreParenCasts();
4685 if (!AddrOpLoc.isValid()) {
4686 FirstOpKind = UnOpKind;
4687 FirstOpLoc = UnOp->getOperatorLoc();
4692 if (FirstOpLoc.isValid()) {
4693 if (ExtWarnMSTemplateArg)
4694 S.Diag(ArgIn->getLocStart(), diag::ext_ms_deref_template_argument)
4695 << ArgIn->getSourceRange();
4697 if (FirstOpKind == UO_AddrOf)
4698 AddressTaken = true;
4699 else if (Arg->getType()->isPointerType()) {
4700 // We cannot let pointers get dereferenced here, that is obviously not a
4701 // constant expression.
4702 assert(FirstOpKind == UO_Deref);
4703 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
4704 << Arg->getSourceRange();
4708 // See through any implicit casts we added to fix the type.
4709 Arg = Arg->IgnoreImpCasts();
4711 // C++ [temp.arg.nontype]p1:
4713 // A template-argument for a non-type, non-template
4714 // template-parameter shall be one of: [...]
4716 // -- the address of an object or function with external
4717 // linkage, including function templates and function
4718 // template-ids but excluding non-static class members,
4719 // expressed as & id-expression where the & is optional if
4720 // the name refers to a function or array, or if the
4721 // corresponding template-parameter is a reference; or
4723 // In C++98/03 mode, give an extension warning on any extra parentheses.
4724 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
4725 bool ExtraParens = false;
4726 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) {
4727 if (!Invalid && !ExtraParens) {
4728 S.Diag(Arg->getLocStart(),
4729 S.getLangOpts().CPlusPlus11
4730 ? diag::warn_cxx98_compat_template_arg_extra_parens
4731 : diag::ext_template_arg_extra_parens)
4732 << Arg->getSourceRange();
4736 Arg = Parens->getSubExpr();
4739 while (SubstNonTypeTemplateParmExpr *subst =
4740 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
4741 Arg = subst->getReplacement()->IgnoreImpCasts();
4743 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
4744 if (UnOp->getOpcode() == UO_AddrOf) {
4745 Arg = UnOp->getSubExpr();
4746 AddressTaken = true;
4747 AddrOpLoc = UnOp->getOperatorLoc();
4751 while (SubstNonTypeTemplateParmExpr *subst =
4752 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
4753 Arg = subst->getReplacement()->IgnoreImpCasts();
4756 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg);
4757 ValueDecl *Entity = DRE ? DRE->getDecl() : nullptr;
4759 // If our parameter has pointer type, check for a null template value.
4760 if (ParamType->isPointerType() || ParamType->isNullPtrType()) {
4761 NullPointerValueKind NPV;
4762 // dllimport'd entities aren't constant but are available inside of template
4764 if (Entity && Entity->hasAttr<DLLImportAttr>())
4765 NPV = NPV_NotNullPointer;
4767 NPV = isNullPointerValueTemplateArgument(S, Param, ParamType, ArgIn);
4769 case NPV_NullPointer:
4770 S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
4771 Converted = TemplateArgument(S.Context.getCanonicalType(ParamType),
4772 /*isNullPtr=*/true);
4778 case NPV_NotNullPointer:
4783 // Stop checking the precise nature of the argument if it is value dependent,
4784 // it should be checked when instantiated.
4785 if (Arg->isValueDependent()) {
4786 Converted = TemplateArgument(ArgIn);
4790 if (isa<CXXUuidofExpr>(Arg)) {
4791 if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType,
4792 ArgIn, Arg, ArgType))
4795 Converted = TemplateArgument(ArgIn);
4800 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
4801 << Arg->getSourceRange();
4802 S.Diag(Param->getLocation(), diag::note_template_param_here);
4806 // Cannot refer to non-static data members
4807 if (isa<FieldDecl>(Entity) || isa<IndirectFieldDecl>(Entity)) {
4808 S.Diag(Arg->getLocStart(), diag::err_template_arg_field)
4809 << Entity << Arg->getSourceRange();
4810 S.Diag(Param->getLocation(), diag::note_template_param_here);
4814 // Cannot refer to non-static member functions
4815 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Entity)) {
4816 if (!Method->isStatic()) {
4817 S.Diag(Arg->getLocStart(), diag::err_template_arg_method)
4818 << Method << Arg->getSourceRange();
4819 S.Diag(Param->getLocation(), diag::note_template_param_here);
4824 FunctionDecl *Func = dyn_cast<FunctionDecl>(Entity);
4825 VarDecl *Var = dyn_cast<VarDecl>(Entity);
4827 // A non-type template argument must refer to an object or function.
4828 if (!Func && !Var) {
4829 // We found something, but we don't know specifically what it is.
4830 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_object_or_func)
4831 << Arg->getSourceRange();
4832 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here);
4836 // Address / reference template args must have external linkage in C++98.
4837 if (Entity->getFormalLinkage() == InternalLinkage) {
4838 S.Diag(Arg->getLocStart(), S.getLangOpts().CPlusPlus11 ?
4839 diag::warn_cxx98_compat_template_arg_object_internal :
4840 diag::ext_template_arg_object_internal)
4841 << !Func << Entity << Arg->getSourceRange();
4842 S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
4844 } else if (!Entity->hasLinkage()) {
4845 S.Diag(Arg->getLocStart(), diag::err_template_arg_object_no_linkage)
4846 << !Func << Entity << Arg->getSourceRange();
4847 S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
4853 // If the template parameter has pointer type, the function decays.
4854 if (ParamType->isPointerType() && !AddressTaken)
4855 ArgType = S.Context.getPointerType(Func->getType());
4856 else if (AddressTaken && ParamType->isReferenceType()) {
4857 // If we originally had an address-of operator, but the
4858 // parameter has reference type, complain and (if things look
4859 // like they will work) drop the address-of operator.
4860 if (!S.Context.hasSameUnqualifiedType(Func->getType(),
4861 ParamType.getNonReferenceType())) {
4862 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4864 S.Diag(Param->getLocation(), diag::note_template_param_here);
4868 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4870 << FixItHint::CreateRemoval(AddrOpLoc);
4871 S.Diag(Param->getLocation(), diag::note_template_param_here);
4873 ArgType = Func->getType();
4876 // A value of reference type is not an object.
4877 if (Var->getType()->isReferenceType()) {
4878 S.Diag(Arg->getLocStart(),
4879 diag::err_template_arg_reference_var)
4880 << Var->getType() << Arg->getSourceRange();
4881 S.Diag(Param->getLocation(), diag::note_template_param_here);
4885 // A template argument must have static storage duration.
4886 if (Var->getTLSKind()) {
4887 S.Diag(Arg->getLocStart(), diag::err_template_arg_thread_local)
4888 << Arg->getSourceRange();
4889 S.Diag(Var->getLocation(), diag::note_template_arg_refers_here);
4893 // If the template parameter has pointer type, we must have taken
4894 // the address of this object.
4895 if (ParamType->isReferenceType()) {
4897 // If we originally had an address-of operator, but the
4898 // parameter has reference type, complain and (if things look
4899 // like they will work) drop the address-of operator.
4900 if (!S.Context.hasSameUnqualifiedType(Var->getType(),
4901 ParamType.getNonReferenceType())) {
4902 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4904 S.Diag(Param->getLocation(), diag::note_template_param_here);
4908 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4910 << FixItHint::CreateRemoval(AddrOpLoc);
4911 S.Diag(Param->getLocation(), diag::note_template_param_here);
4913 ArgType = Var->getType();
4915 } else if (!AddressTaken && ParamType->isPointerType()) {
4916 if (Var->getType()->isArrayType()) {
4917 // Array-to-pointer decay.
4918 ArgType = S.Context.getArrayDecayedType(Var->getType());
4920 // If the template parameter has pointer type but the address of
4921 // this object was not taken, complain and (possibly) recover by
4922 // taking the address of the entity.
4923 ArgType = S.Context.getPointerType(Var->getType());
4924 if (!S.Context.hasSameUnqualifiedType(ArgType, ParamType)) {
4925 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of)
4927 S.Diag(Param->getLocation(), diag::note_template_param_here);
4931 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of)
4933 << FixItHint::CreateInsertion(Arg->getLocStart(), "&");
4935 S.Diag(Param->getLocation(), diag::note_template_param_here);
4940 if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType, ArgIn,
4944 // Create the template argument.
4946 TemplateArgument(cast<ValueDecl>(Entity->getCanonicalDecl()), ParamType);
4947 S.MarkAnyDeclReferenced(Arg->getLocStart(), Entity, false);
4951 /// \brief Checks whether the given template argument is a pointer to
4952 /// member constant according to C++ [temp.arg.nontype]p1.
4953 static bool CheckTemplateArgumentPointerToMember(Sema &S,
4954 NonTypeTemplateParmDecl *Param,
4957 TemplateArgument &Converted) {
4958 bool Invalid = false;
4960 // Check for a null pointer value.
4961 Expr *Arg = ResultArg;
4962 switch (isNullPointerValueTemplateArgument(S, Param, ParamType, Arg)) {
4965 case NPV_NullPointer:
4966 S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
4967 Converted = TemplateArgument(S.Context.getCanonicalType(ParamType),
4970 case NPV_NotNullPointer:
4974 bool ObjCLifetimeConversion;
4975 if (S.IsQualificationConversion(Arg->getType(),
4976 ParamType.getNonReferenceType(),
4977 false, ObjCLifetimeConversion)) {
4978 Arg = S.ImpCastExprToType(Arg, ParamType, CK_NoOp,
4979 Arg->getValueKind()).get();
4981 } else if (!S.Context.hasSameUnqualifiedType(Arg->getType(),
4982 ParamType.getNonReferenceType())) {
4983 // We can't perform this conversion.
4984 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible)
4985 << Arg->getType() << ParamType << Arg->getSourceRange();
4986 S.Diag(Param->getLocation(), diag::note_template_param_here);
4990 // See through any implicit casts we added to fix the type.
4991 while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg))
4992 Arg = Cast->getSubExpr();
4994 // C++ [temp.arg.nontype]p1:
4996 // A template-argument for a non-type, non-template
4997 // template-parameter shall be one of: [...]
4999 // -- a pointer to member expressed as described in 5.3.1.
5000 DeclRefExpr *DRE = nullptr;
5002 // In C++98/03 mode, give an extension warning on any extra parentheses.
5003 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
5004 bool ExtraParens = false;
5005 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) {
5006 if (!Invalid && !ExtraParens) {
5007 S.Diag(Arg->getLocStart(),
5008 S.getLangOpts().CPlusPlus11 ?
5009 diag::warn_cxx98_compat_template_arg_extra_parens :
5010 diag::ext_template_arg_extra_parens)
5011 << Arg->getSourceRange();
5015 Arg = Parens->getSubExpr();
5018 while (SubstNonTypeTemplateParmExpr *subst =
5019 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
5020 Arg = subst->getReplacement()->IgnoreImpCasts();
5022 // A pointer-to-member constant written &Class::member.
5023 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
5024 if (UnOp->getOpcode() == UO_AddrOf) {
5025 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr());
5026 if (DRE && !DRE->getQualifier())
5030 // A constant of pointer-to-member type.
5031 else if ((DRE = dyn_cast<DeclRefExpr>(Arg))) {
5032 if (ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl())) {
5033 if (VD->getType()->isMemberPointerType()) {
5034 if (isa<NonTypeTemplateParmDecl>(VD)) {
5035 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
5036 Converted = TemplateArgument(Arg);
5038 VD = cast<ValueDecl>(VD->getCanonicalDecl());
5039 Converted = TemplateArgument(VD, ParamType);
5050 return S.Diag(Arg->getLocStart(),
5051 diag::err_template_arg_not_pointer_to_member_form)
5052 << Arg->getSourceRange();
5054 if (isa<FieldDecl>(DRE->getDecl()) ||
5055 isa<IndirectFieldDecl>(DRE->getDecl()) ||
5056 isa<CXXMethodDecl>(DRE->getDecl())) {
5057 assert((isa<FieldDecl>(DRE->getDecl()) ||
5058 isa<IndirectFieldDecl>(DRE->getDecl()) ||
5059 !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) &&
5060 "Only non-static member pointers can make it here");
5062 // Okay: this is the address of a non-static member, and therefore
5063 // a member pointer constant.
5064 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
5065 Converted = TemplateArgument(Arg);
5067 ValueDecl *D = cast<ValueDecl>(DRE->getDecl()->getCanonicalDecl());
5068 Converted = TemplateArgument(D, ParamType);
5073 // We found something else, but we don't know specifically what it is.
5074 S.Diag(Arg->getLocStart(),
5075 diag::err_template_arg_not_pointer_to_member_form)
5076 << Arg->getSourceRange();
5077 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here);
5081 /// \brief Check a template argument against its corresponding
5082 /// non-type template parameter.
5084 /// This routine implements the semantics of C++ [temp.arg.nontype].
5085 /// If an error occurred, it returns ExprError(); otherwise, it
5086 /// returns the converted template argument. \p ParamType is the
5087 /// type of the non-type template parameter after it has been instantiated.
5088 ExprResult Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
5089 QualType ParamType, Expr *Arg,
5090 TemplateArgument &Converted,
5091 CheckTemplateArgumentKind CTAK) {
5092 SourceLocation StartLoc = Arg->getLocStart();
5094 // If the parameter type somehow involves auto, deduce the type now.
5095 if (getLangOpts().CPlusPlus1z && ParamType->isUndeducedType()) {
5096 // When checking a deduced template argument, deduce from its type even if
5097 // the type is dependent, in order to check the types of non-type template
5098 // arguments line up properly in partial ordering.
5099 Optional<unsigned> Depth;
5100 if (CTAK != CTAK_Specified)
5101 Depth = Param->getDepth() + 1;
5103 Context.getTrivialTypeSourceInfo(ParamType, Param->getLocation()),
5104 Arg, ParamType, Depth) == DAR_Failed) {
5105 Diag(Arg->getExprLoc(),
5106 diag::err_non_type_template_parm_type_deduction_failure)
5107 << Param->getDeclName() << Param->getType() << Arg->getType()
5108 << Arg->getSourceRange();
5109 Diag(Param->getLocation(), diag::note_template_param_here);
5112 // CheckNonTypeTemplateParameterType will produce a diagnostic if there's
5113 // an error. The error message normally references the parameter
5114 // declaration, but here we'll pass the argument location because that's
5115 // where the parameter type is deduced.
5116 ParamType = CheckNonTypeTemplateParameterType(ParamType, Arg->getExprLoc());
5117 if (ParamType.isNull()) {
5118 Diag(Param->getLocation(), diag::note_template_param_here);
5123 // We should have already dropped all cv-qualifiers by now.
5124 assert(!ParamType.hasQualifiers() &&
5125 "non-type template parameter type cannot be qualified");
5127 if (CTAK == CTAK_Deduced &&
5128 !Context.hasSameType(ParamType.getNonLValueExprType(Context),
5130 // FIXME: If either type is dependent, we skip the check. This isn't
5131 // correct, since during deduction we're supposed to have replaced each
5132 // template parameter with some unique (non-dependent) placeholder.
5133 // FIXME: If the argument type contains 'auto', we carry on and fail the
5134 // type check in order to force specific types to be more specialized than
5135 // 'auto'. It's not clear how partial ordering with 'auto' is supposed to
5137 if ((ParamType->isDependentType() || Arg->isTypeDependent()) &&
5138 !Arg->getType()->getContainedAutoType()) {
5139 Converted = TemplateArgument(Arg);
5142 // FIXME: This attempts to implement C++ [temp.deduct.type]p17. Per DR1770,
5143 // we should actually be checking the type of the template argument in P,
5144 // not the type of the template argument deduced from A, against the
5145 // template parameter type.
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 // The initialization of the parameter from the argument is
5162 // a constant-evaluated context.
5163 EnterExpressionEvaluationContext ConstantEvaluated(*this,
5164 Sema::ConstantEvaluated);
5166 if (getLangOpts().CPlusPlus1z) {
5167 // C++1z [temp.arg.nontype]p1:
5168 // A template-argument for a non-type template parameter shall be
5169 // a converted constant expression of the type of the template-parameter.
5171 ExprResult ArgResult = CheckConvertedConstantExpression(
5172 Arg, ParamType, Value, CCEK_TemplateArg);
5173 if (ArgResult.isInvalid())
5176 // For a value-dependent argument, CheckConvertedConstantExpression is
5177 // permitted (and expected) to be unable to determine a value.
5178 if (ArgResult.get()->isValueDependent()) {
5179 Converted = TemplateArgument(ArgResult.get());
5183 QualType CanonParamType = Context.getCanonicalType(ParamType);
5185 // Convert the APValue to a TemplateArgument.
5186 switch (Value.getKind()) {
5187 case APValue::Uninitialized:
5188 assert(ParamType->isNullPtrType());
5189 Converted = TemplateArgument(CanonParamType, /*isNullPtr*/true);
5192 assert(ParamType->isIntegralOrEnumerationType());
5193 Converted = TemplateArgument(Context, Value.getInt(), CanonParamType);
5195 case APValue::MemberPointer: {
5196 assert(ParamType->isMemberPointerType());
5198 // FIXME: We need TemplateArgument representation and mangling for these.
5199 if (!Value.getMemberPointerPath().empty()) {
5200 Diag(Arg->getLocStart(),
5201 diag::err_template_arg_member_ptr_base_derived_not_supported)
5202 << Value.getMemberPointerDecl() << ParamType
5203 << Arg->getSourceRange();
5207 auto *VD = const_cast<ValueDecl*>(Value.getMemberPointerDecl());
5208 Converted = VD ? TemplateArgument(VD, CanonParamType)
5209 : TemplateArgument(CanonParamType, /*isNullPtr*/true);
5212 case APValue::LValue: {
5213 // For a non-type template-parameter of pointer or reference type,
5214 // the value of the constant expression shall not refer to
5215 assert(ParamType->isPointerType() || ParamType->isReferenceType() ||
5216 ParamType->isNullPtrType());
5217 // -- a temporary object
5218 // -- a string literal
5219 // -- the result of a typeid expression, or
5220 // -- a predefind __func__ variable
5221 if (auto *E = Value.getLValueBase().dyn_cast<const Expr*>()) {
5222 if (isa<CXXUuidofExpr>(E)) {
5223 Converted = TemplateArgument(const_cast<Expr*>(E));
5226 Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
5227 << Arg->getSourceRange();
5230 auto *VD = const_cast<ValueDecl *>(
5231 Value.getLValueBase().dyn_cast<const ValueDecl *>());
5233 if (Value.hasLValuePath() && Value.getLValuePath().size() == 1 &&
5234 VD && VD->getType()->isArrayType() &&
5235 Value.getLValuePath()[0].ArrayIndex == 0 &&
5236 !Value.isLValueOnePastTheEnd() && ParamType->isPointerType()) {
5237 // Per defect report (no number yet):
5238 // ... other than a pointer to the first element of a complete array
5240 } else if (!Value.hasLValuePath() || Value.getLValuePath().size() ||
5241 Value.isLValueOnePastTheEnd()) {
5242 Diag(StartLoc, diag::err_non_type_template_arg_subobject)
5243 << Value.getAsString(Context, ParamType);
5246 assert((VD || !ParamType->isReferenceType()) &&
5247 "null reference should not be a constant expression");
5248 assert((!VD || !ParamType->isNullPtrType()) &&
5249 "non-null value of type nullptr_t?");
5250 Converted = VD ? TemplateArgument(VD, CanonParamType)
5251 : TemplateArgument(CanonParamType, /*isNullPtr*/true);
5254 case APValue::AddrLabelDiff:
5255 return Diag(StartLoc, diag::err_non_type_template_arg_addr_label_diff);
5256 case APValue::Float:
5257 case APValue::ComplexInt:
5258 case APValue::ComplexFloat:
5259 case APValue::Vector:
5260 case APValue::Array:
5261 case APValue::Struct:
5262 case APValue::Union:
5263 llvm_unreachable("invalid kind for template argument");
5266 return ArgResult.get();
5269 // C++ [temp.arg.nontype]p5:
5270 // The following conversions are performed on each expression used
5271 // as a non-type template-argument. If a non-type
5272 // template-argument cannot be converted to the type of the
5273 // corresponding template-parameter then the program is
5275 if (ParamType->isIntegralOrEnumerationType()) {
5277 // -- for a non-type template-parameter of integral or
5278 // enumeration type, conversions permitted in a converted
5279 // constant expression are applied.
5282 // -- for a non-type template-parameter of integral or
5283 // enumeration type, integral promotions (4.5) and integral
5284 // conversions (4.7) are applied.
5286 if (getLangOpts().CPlusPlus11) {
5287 // C++ [temp.arg.nontype]p1:
5288 // A template-argument for a non-type, non-template template-parameter
5291 // -- for a non-type template-parameter of integral or enumeration
5292 // type, a converted constant expression of the type of the
5293 // template-parameter; or
5295 ExprResult ArgResult =
5296 CheckConvertedConstantExpression(Arg, ParamType, Value,
5298 if (ArgResult.isInvalid())
5301 // We can't check arbitrary value-dependent arguments.
5302 if (ArgResult.get()->isValueDependent()) {
5303 Converted = TemplateArgument(ArgResult.get());
5307 // Widen the argument value to sizeof(parameter type). This is almost
5308 // always a no-op, except when the parameter type is bool. In
5309 // that case, this may extend the argument from 1 bit to 8 bits.
5310 QualType IntegerType = ParamType;
5311 if (const EnumType *Enum = IntegerType->getAs<EnumType>())
5312 IntegerType = Enum->getDecl()->getIntegerType();
5313 Value = Value.extOrTrunc(Context.getTypeSize(IntegerType));
5315 Converted = TemplateArgument(Context, Value,
5316 Context.getCanonicalType(ParamType));
5320 ExprResult ArgResult = DefaultLvalueConversion(Arg);
5321 if (ArgResult.isInvalid())
5323 Arg = ArgResult.get();
5325 QualType ArgType = Arg->getType();
5327 // C++ [temp.arg.nontype]p1:
5328 // A template-argument for a non-type, non-template
5329 // template-parameter shall be one of:
5331 // -- an integral constant-expression of integral or enumeration
5333 // -- the name of a non-type template-parameter; or
5334 SourceLocation NonConstantLoc;
5336 if (!ArgType->isIntegralOrEnumerationType()) {
5337 Diag(Arg->getLocStart(),
5338 diag::err_template_arg_not_integral_or_enumeral)
5339 << ArgType << Arg->getSourceRange();
5340 Diag(Param->getLocation(), diag::note_template_param_here);
5342 } else if (!Arg->isValueDependent()) {
5343 class TmplArgICEDiagnoser : public VerifyICEDiagnoser {
5347 TmplArgICEDiagnoser(QualType T) : T(T) { }
5349 void diagnoseNotICE(Sema &S, SourceLocation Loc,
5350 SourceRange SR) override {
5351 S.Diag(Loc, diag::err_template_arg_not_ice) << T << SR;
5353 } Diagnoser(ArgType);
5355 Arg = VerifyIntegerConstantExpression(Arg, &Value, Diagnoser,
5361 // From here on out, all we care about is the unqualified form
5362 // of the argument type.
5363 ArgType = ArgType.getUnqualifiedType();
5365 // Try to convert the argument to the parameter's type.
5366 if (Context.hasSameType(ParamType, ArgType)) {
5367 // Okay: no conversion necessary
5368 } else if (ParamType->isBooleanType()) {
5369 // This is an integral-to-boolean conversion.
5370 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralToBoolean).get();
5371 } else if (IsIntegralPromotion(Arg, ArgType, ParamType) ||
5372 !ParamType->isEnumeralType()) {
5373 // This is an integral promotion or conversion.
5374 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralCast).get();
5376 // We can't perform this conversion.
5377 Diag(Arg->getLocStart(),
5378 diag::err_template_arg_not_convertible)
5379 << Arg->getType() << ParamType << Arg->getSourceRange();
5380 Diag(Param->getLocation(), diag::note_template_param_here);
5384 // Add the value of this argument to the list of converted
5385 // arguments. We use the bitwidth and signedness of the template
5387 if (Arg->isValueDependent()) {
5388 // The argument is value-dependent. Create a new
5389 // TemplateArgument with the converted expression.
5390 Converted = TemplateArgument(Arg);
5394 QualType IntegerType = Context.getCanonicalType(ParamType);
5395 if (const EnumType *Enum = IntegerType->getAs<EnumType>())
5396 IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType());
5398 if (ParamType->isBooleanType()) {
5399 // Value must be zero or one.
5401 unsigned AllowedBits = Context.getTypeSize(IntegerType);
5402 if (Value.getBitWidth() != AllowedBits)
5403 Value = Value.extOrTrunc(AllowedBits);
5404 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
5406 llvm::APSInt OldValue = Value;
5408 // Coerce the template argument's value to the value it will have
5409 // based on the template parameter's type.
5410 unsigned AllowedBits = Context.getTypeSize(IntegerType);
5411 if (Value.getBitWidth() != AllowedBits)
5412 Value = Value.extOrTrunc(AllowedBits);
5413 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
5415 // Complain if an unsigned parameter received a negative value.
5416 if (IntegerType->isUnsignedIntegerOrEnumerationType()
5417 && (OldValue.isSigned() && OldValue.isNegative())) {
5418 Diag(Arg->getLocStart(), diag::warn_template_arg_negative)
5419 << OldValue.toString(10) << Value.toString(10) << Param->getType()
5420 << Arg->getSourceRange();
5421 Diag(Param->getLocation(), diag::note_template_param_here);
5424 // Complain if we overflowed the template parameter's type.
5425 unsigned RequiredBits;
5426 if (IntegerType->isUnsignedIntegerOrEnumerationType())
5427 RequiredBits = OldValue.getActiveBits();
5428 else if (OldValue.isUnsigned())
5429 RequiredBits = OldValue.getActiveBits() + 1;
5431 RequiredBits = OldValue.getMinSignedBits();
5432 if (RequiredBits > AllowedBits) {
5433 Diag(Arg->getLocStart(),
5434 diag::warn_template_arg_too_large)
5435 << OldValue.toString(10) << Value.toString(10) << Param->getType()
5436 << Arg->getSourceRange();
5437 Diag(Param->getLocation(), diag::note_template_param_here);
5441 Converted = TemplateArgument(Context, Value,
5442 ParamType->isEnumeralType()
5443 ? Context.getCanonicalType(ParamType)
5448 QualType ArgType = Arg->getType();
5449 DeclAccessPair FoundResult; // temporary for ResolveOverloadedFunction
5451 // Handle pointer-to-function, reference-to-function, and
5452 // pointer-to-member-function all in (roughly) the same way.
5453 if (// -- For a non-type template-parameter of type pointer to
5454 // function, only the function-to-pointer conversion (4.3) is
5455 // applied. If the template-argument represents a set of
5456 // overloaded functions (or a pointer to such), the matching
5457 // function is selected from the set (13.4).
5458 (ParamType->isPointerType() &&
5459 ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType()) ||
5460 // -- For a non-type template-parameter of type reference to
5461 // function, no conversions apply. If the template-argument
5462 // represents a set of overloaded functions, the matching
5463 // function is selected from the set (13.4).
5464 (ParamType->isReferenceType() &&
5465 ParamType->getAs<ReferenceType>()->getPointeeType()->isFunctionType()) ||
5466 // -- For a non-type template-parameter of type pointer to
5467 // member function, no conversions apply. If the
5468 // template-argument represents a set of overloaded member
5469 // functions, the matching member function is selected from
5471 (ParamType->isMemberPointerType() &&
5472 ParamType->getAs<MemberPointerType>()->getPointeeType()
5473 ->isFunctionType())) {
5475 if (Arg->getType() == Context.OverloadTy) {
5476 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType,
5479 if (DiagnoseUseOfDecl(Fn, Arg->getLocStart()))
5482 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
5483 ArgType = Arg->getType();
5488 if (!ParamType->isMemberPointerType()) {
5489 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5496 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
5502 if (ParamType->isPointerType()) {
5503 // -- for a non-type template-parameter of type pointer to
5504 // object, qualification conversions (4.4) and the
5505 // array-to-pointer conversion (4.2) are applied.
5506 // C++0x also allows a value of std::nullptr_t.
5507 assert(ParamType->getPointeeType()->isIncompleteOrObjectType() &&
5508 "Only object pointers allowed here");
5510 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5517 if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) {
5518 // -- For a non-type template-parameter of type reference to
5519 // object, no conversions apply. The type referred to by the
5520 // reference may be more cv-qualified than the (otherwise
5521 // identical) type of the template-argument. The
5522 // template-parameter is bound directly to the
5523 // template-argument, which must be an lvalue.
5524 assert(ParamRefType->getPointeeType()->isIncompleteOrObjectType() &&
5525 "Only object references allowed here");
5527 if (Arg->getType() == Context.OverloadTy) {
5528 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg,
5529 ParamRefType->getPointeeType(),
5532 if (DiagnoseUseOfDecl(Fn, Arg->getLocStart()))
5535 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
5536 ArgType = Arg->getType();
5541 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5548 // Deal with parameters of type std::nullptr_t.
5549 if (ParamType->isNullPtrType()) {
5550 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
5551 Converted = TemplateArgument(Arg);
5555 switch (isNullPointerValueTemplateArgument(*this, Param, ParamType, Arg)) {
5556 case NPV_NotNullPointer:
5557 Diag(Arg->getExprLoc(), diag::err_template_arg_not_convertible)
5558 << Arg->getType() << ParamType;
5559 Diag(Param->getLocation(), diag::note_template_param_here);
5565 case NPV_NullPointer:
5566 Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
5567 Converted = TemplateArgument(Context.getCanonicalType(ParamType),
5573 // -- For a non-type template-parameter of type pointer to data
5574 // member, qualification conversions (4.4) are applied.
5575 assert(ParamType->isMemberPointerType() && "Only pointers to members remain");
5577 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
5583 static void DiagnoseTemplateParameterListArityMismatch(
5584 Sema &S, TemplateParameterList *New, TemplateParameterList *Old,
5585 Sema::TemplateParameterListEqualKind Kind, SourceLocation TemplateArgLoc);
5587 /// \brief Check a template argument against its corresponding
5588 /// template template parameter.
5590 /// This routine implements the semantics of C++ [temp.arg.template].
5591 /// It returns true if an error occurred, and false otherwise.
5592 bool Sema::CheckTemplateArgument(TemplateTemplateParmDecl *Param,
5593 TemplateArgumentLoc &Arg,
5594 unsigned ArgumentPackIndex) {
5595 TemplateName Name = Arg.getArgument().getAsTemplateOrTemplatePattern();
5596 TemplateDecl *Template = Name.getAsTemplateDecl();
5598 // Any dependent template name is fine.
5599 assert(Name.isDependent() && "Non-dependent template isn't a declaration?");
5603 if (Template->isInvalidDecl())
5606 // C++0x [temp.arg.template]p1:
5607 // A template-argument for a template template-parameter shall be
5608 // the name of a class template or an alias template, expressed as an
5609 // id-expression. When the template-argument names a class template, only
5610 // primary class templates are considered when matching the
5611 // template template argument with the corresponding parameter;
5612 // partial specializations are not considered even if their
5613 // parameter lists match that of the template template parameter.
5615 // Note that we also allow template template parameters here, which
5616 // will happen when we are dealing with, e.g., class template
5617 // partial specializations.
5618 if (!isa<ClassTemplateDecl>(Template) &&
5619 !isa<TemplateTemplateParmDecl>(Template) &&
5620 !isa<TypeAliasTemplateDecl>(Template) &&
5621 !isa<BuiltinTemplateDecl>(Template)) {
5622 assert(isa<FunctionTemplateDecl>(Template) &&
5623 "Only function templates are possible here");
5624 Diag(Arg.getLocation(), diag::err_template_arg_not_valid_template);
5625 Diag(Template->getLocation(), diag::note_template_arg_refers_here_func)
5629 TemplateParameterList *Params = Param->getTemplateParameters();
5630 if (Param->isExpandedParameterPack())
5631 Params = Param->getExpansionTemplateParameters(ArgumentPackIndex);
5633 // C++1z [temp.arg.template]p3: (DR 150)
5634 // A template-argument matches a template template-parameter P when P
5635 // is at least as specialized as the template-argument A.
5636 if (getLangOpts().RelaxedTemplateTemplateArgs) {
5637 // Quick check for the common case:
5638 // If P contains a parameter pack, then A [...] matches P if each of A's
5639 // template parameters matches the corresponding template parameter in
5640 // the template-parameter-list of P.
5641 if (TemplateParameterListsAreEqual(
5642 Template->getTemplateParameters(), Params, false,
5643 TPL_TemplateTemplateArgumentMatch, Arg.getLocation()))
5646 if (isTemplateTemplateParameterAtLeastAsSpecializedAs(Params, Template,
5649 // FIXME: Produce better diagnostics for deduction failures.
5652 return !TemplateParameterListsAreEqual(Template->getTemplateParameters(),
5655 TPL_TemplateTemplateArgumentMatch,
5659 /// \brief Given a non-type template argument that refers to a
5660 /// declaration and the type of its corresponding non-type template
5661 /// parameter, produce an expression that properly refers to that
5664 Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
5666 SourceLocation Loc) {
5667 // C++ [temp.param]p8:
5669 // A non-type template-parameter of type "array of T" or
5670 // "function returning T" is adjusted to be of type "pointer to
5671 // T" or "pointer to function returning T", respectively.
5672 if (ParamType->isArrayType())
5673 ParamType = Context.getArrayDecayedType(ParamType);
5674 else if (ParamType->isFunctionType())
5675 ParamType = Context.getPointerType(ParamType);
5677 // For a NULL non-type template argument, return nullptr casted to the
5678 // parameter's type.
5679 if (Arg.getKind() == TemplateArgument::NullPtr) {
5680 return ImpCastExprToType(
5681 new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc),
5683 ParamType->getAs<MemberPointerType>()
5684 ? CK_NullToMemberPointer
5685 : CK_NullToPointer);
5687 assert(Arg.getKind() == TemplateArgument::Declaration &&
5688 "Only declaration template arguments permitted here");
5690 ValueDecl *VD = cast<ValueDecl>(Arg.getAsDecl());
5692 if (VD->getDeclContext()->isRecord() &&
5693 (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD) ||
5694 isa<IndirectFieldDecl>(VD))) {
5695 // If the value is a class member, we might have a pointer-to-member.
5696 // Determine whether the non-type template template parameter is of
5697 // pointer-to-member type. If so, we need to build an appropriate
5698 // expression for a pointer-to-member, since a "normal" DeclRefExpr
5699 // would refer to the member itself.
5700 if (ParamType->isMemberPointerType()) {
5702 = Context.getTypeDeclType(cast<RecordDecl>(VD->getDeclContext()));
5703 NestedNameSpecifier *Qualifier
5704 = NestedNameSpecifier::Create(Context, nullptr, false,
5705 ClassType.getTypePtr());
5707 SS.MakeTrivial(Context, Qualifier, Loc);
5709 // The actual value-ness of this is unimportant, but for
5710 // internal consistency's sake, references to instance methods
5712 ExprValueKind VK = VK_LValue;
5713 if (isa<CXXMethodDecl>(VD) && cast<CXXMethodDecl>(VD)->isInstance())
5716 ExprResult RefExpr = BuildDeclRefExpr(VD,
5717 VD->getType().getNonReferenceType(),
5721 if (RefExpr.isInvalid())
5724 RefExpr = CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
5726 // We might need to perform a trailing qualification conversion, since
5727 // the element type on the parameter could be more qualified than the
5728 // element type in the expression we constructed.
5729 bool ObjCLifetimeConversion;
5730 if (IsQualificationConversion(((Expr*) RefExpr.get())->getType(),
5731 ParamType.getUnqualifiedType(), false,
5732 ObjCLifetimeConversion))
5733 RefExpr = ImpCastExprToType(RefExpr.get(), ParamType.getUnqualifiedType(), CK_NoOp);
5735 assert(!RefExpr.isInvalid() &&
5736 Context.hasSameType(((Expr*) RefExpr.get())->getType(),
5737 ParamType.getUnqualifiedType()));
5742 QualType T = VD->getType().getNonReferenceType();
5744 if (ParamType->isPointerType()) {
5745 // When the non-type template parameter is a pointer, take the
5746 // address of the declaration.
5747 ExprResult RefExpr = BuildDeclRefExpr(VD, T, VK_LValue, Loc);
5748 if (RefExpr.isInvalid())
5751 if (T->isFunctionType() || T->isArrayType()) {
5752 // Decay functions and arrays.
5753 RefExpr = DefaultFunctionArrayConversion(RefExpr.get());
5754 if (RefExpr.isInvalid())
5760 // Take the address of everything else
5761 return CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
5764 ExprValueKind VK = VK_RValue;
5766 // If the non-type template parameter has reference type, qualify the
5767 // resulting declaration reference with the extra qualifiers on the
5768 // type that the reference refers to.
5769 if (const ReferenceType *TargetRef = ParamType->getAs<ReferenceType>()) {
5771 T = Context.getQualifiedType(T,
5772 TargetRef->getPointeeType().getQualifiers());
5773 } else if (isa<FunctionDecl>(VD)) {
5774 // References to functions are always lvalues.
5778 return BuildDeclRefExpr(VD, T, VK, Loc);
5781 /// \brief Construct a new expression that refers to the given
5782 /// integral template argument with the given source-location
5785 /// This routine takes care of the mapping from an integral template
5786 /// argument (which may have any integral type) to the appropriate
5789 Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg,
5790 SourceLocation Loc) {
5791 assert(Arg.getKind() == TemplateArgument::Integral &&
5792 "Operation is only valid for integral template arguments");
5793 QualType OrigT = Arg.getIntegralType();
5795 // If this is an enum type that we're instantiating, we need to use an integer
5796 // type the same size as the enumerator. We don't want to build an
5797 // IntegerLiteral with enum type. The integer type of an enum type can be of
5798 // any integral type with C++11 enum classes, make sure we create the right
5799 // type of literal for it.
5801 if (const EnumType *ET = OrigT->getAs<EnumType>())
5802 T = ET->getDecl()->getIntegerType();
5805 if (T->isAnyCharacterType()) {
5806 // This does not need to handle u8 character literals because those are
5807 // of type char, and so can also be covered by an ASCII character literal.
5808 CharacterLiteral::CharacterKind Kind;
5809 if (T->isWideCharType())
5810 Kind = CharacterLiteral::Wide;
5811 else if (T->isChar16Type())
5812 Kind = CharacterLiteral::UTF16;
5813 else if (T->isChar32Type())
5814 Kind = CharacterLiteral::UTF32;
5816 Kind = CharacterLiteral::Ascii;
5818 E = new (Context) CharacterLiteral(Arg.getAsIntegral().getZExtValue(),
5820 } else if (T->isBooleanType()) {
5821 E = new (Context) CXXBoolLiteralExpr(Arg.getAsIntegral().getBoolValue(),
5823 } else if (T->isNullPtrType()) {
5824 E = new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
5826 E = IntegerLiteral::Create(Context, Arg.getAsIntegral(), T, Loc);
5829 if (OrigT->isEnumeralType()) {
5830 // FIXME: This is a hack. We need a better way to handle substituted
5831 // non-type template parameters.
5832 E = CStyleCastExpr::Create(Context, OrigT, VK_RValue, CK_IntegralCast, E,
5834 Context.getTrivialTypeSourceInfo(OrigT, Loc),
5841 static bool isDependentOnOuter(NonTypeTemplateParmDecl *NTTP) {
5842 if (NTTP->getDepth() == 0 || !NTTP->getType()->isDependentType())
5844 DependencyChecker Checker(NTTP->getDepth(), /*IgnoreNonTypeDependent*/ false,
5845 /*FindLessThanDepth*/ true);
5846 Checker.TraverseType(NTTP->getType());
5847 return Checker.Match;
5850 /// \brief Match two template parameters within template parameter lists.
5851 static bool MatchTemplateParameterKind(Sema &S, NamedDecl *New, NamedDecl *Old,
5853 Sema::TemplateParameterListEqualKind Kind,
5854 SourceLocation TemplateArgLoc) {
5855 // Check the actual kind (type, non-type, template).
5856 if (Old->getKind() != New->getKind()) {
5858 unsigned NextDiag = diag::err_template_param_different_kind;
5859 if (TemplateArgLoc.isValid()) {
5860 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
5861 NextDiag = diag::note_template_param_different_kind;
5863 S.Diag(New->getLocation(), NextDiag)
5864 << (Kind != Sema::TPL_TemplateMatch);
5865 S.Diag(Old->getLocation(), diag::note_template_prev_declaration)
5866 << (Kind != Sema::TPL_TemplateMatch);
5872 // Check that both are parameter packs or neither are parameter packs.
5873 // However, if we are matching a template template argument to a
5874 // template template parameter, the template template parameter can have
5875 // a parameter pack where the template template argument does not.
5876 if (Old->isTemplateParameterPack() != New->isTemplateParameterPack() &&
5877 !(Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
5878 Old->isTemplateParameterPack())) {
5880 unsigned NextDiag = diag::err_template_parameter_pack_non_pack;
5881 if (TemplateArgLoc.isValid()) {
5882 S.Diag(TemplateArgLoc,
5883 diag::err_template_arg_template_params_mismatch);
5884 NextDiag = diag::note_template_parameter_pack_non_pack;
5887 unsigned ParamKind = isa<TemplateTypeParmDecl>(New)? 0
5888 : isa<NonTypeTemplateParmDecl>(New)? 1
5890 S.Diag(New->getLocation(), NextDiag)
5891 << ParamKind << New->isParameterPack();
5892 S.Diag(Old->getLocation(), diag::note_template_parameter_pack_here)
5893 << ParamKind << Old->isParameterPack();
5899 // For non-type template parameters, check the type of the parameter.
5900 if (NonTypeTemplateParmDecl *OldNTTP
5901 = dyn_cast<NonTypeTemplateParmDecl>(Old)) {
5902 NonTypeTemplateParmDecl *NewNTTP = cast<NonTypeTemplateParmDecl>(New);
5904 // If we are matching a template template argument to a template
5905 // template parameter and one of the non-type template parameter types
5906 // is dependent on an outer template's parameter, then we must wait until
5907 // template instantiation time to actually compare the arguments.
5908 if (Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
5909 (isDependentOnOuter(OldNTTP) || isDependentOnOuter(NewNTTP)))
5912 if (!S.Context.hasSameType(OldNTTP->getType(), NewNTTP->getType())) {
5914 unsigned NextDiag = diag::err_template_nontype_parm_different_type;
5915 if (TemplateArgLoc.isValid()) {
5916 S.Diag(TemplateArgLoc,
5917 diag::err_template_arg_template_params_mismatch);
5918 NextDiag = diag::note_template_nontype_parm_different_type;
5920 S.Diag(NewNTTP->getLocation(), NextDiag)
5921 << NewNTTP->getType()
5922 << (Kind != Sema::TPL_TemplateMatch);
5923 S.Diag(OldNTTP->getLocation(),
5924 diag::note_template_nontype_parm_prev_declaration)
5925 << OldNTTP->getType();
5934 // For template template parameters, check the template parameter types.
5935 // The template parameter lists of template template
5936 // parameters must agree.
5937 if (TemplateTemplateParmDecl *OldTTP
5938 = dyn_cast<TemplateTemplateParmDecl>(Old)) {
5939 TemplateTemplateParmDecl *NewTTP = cast<TemplateTemplateParmDecl>(New);
5940 return S.TemplateParameterListsAreEqual(NewTTP->getTemplateParameters(),
5941 OldTTP->getTemplateParameters(),
5943 (Kind == Sema::TPL_TemplateMatch
5944 ? Sema::TPL_TemplateTemplateParmMatch
5952 /// \brief Diagnose a known arity mismatch when comparing template argument
5955 void DiagnoseTemplateParameterListArityMismatch(Sema &S,
5956 TemplateParameterList *New,
5957 TemplateParameterList *Old,
5958 Sema::TemplateParameterListEqualKind Kind,
5959 SourceLocation TemplateArgLoc) {
5960 unsigned NextDiag = diag::err_template_param_list_different_arity;
5961 if (TemplateArgLoc.isValid()) {
5962 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
5963 NextDiag = diag::note_template_param_list_different_arity;
5965 S.Diag(New->getTemplateLoc(), NextDiag)
5966 << (New->size() > Old->size())
5967 << (Kind != Sema::TPL_TemplateMatch)
5968 << SourceRange(New->getTemplateLoc(), New->getRAngleLoc());
5969 S.Diag(Old->getTemplateLoc(), diag::note_template_prev_declaration)
5970 << (Kind != Sema::TPL_TemplateMatch)
5971 << SourceRange(Old->getTemplateLoc(), Old->getRAngleLoc());
5974 /// \brief Determine whether the given template parameter lists are
5977 /// \param New The new template parameter list, typically written in the
5978 /// source code as part of a new template declaration.
5980 /// \param Old The old template parameter list, typically found via
5981 /// name lookup of the template declared with this template parameter
5984 /// \param Complain If true, this routine will produce a diagnostic if
5985 /// the template parameter lists are not equivalent.
5987 /// \param Kind describes how we are to match the template parameter lists.
5989 /// \param TemplateArgLoc If this source location is valid, then we
5990 /// are actually checking the template parameter list of a template
5991 /// argument (New) against the template parameter list of its
5992 /// corresponding template template parameter (Old). We produce
5993 /// slightly different diagnostics in this scenario.
5995 /// \returns True if the template parameter lists are equal, false
5998 Sema::TemplateParameterListsAreEqual(TemplateParameterList *New,
5999 TemplateParameterList *Old,
6001 TemplateParameterListEqualKind Kind,
6002 SourceLocation TemplateArgLoc) {
6003 if (Old->size() != New->size() && Kind != TPL_TemplateTemplateArgumentMatch) {
6005 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
6011 // C++0x [temp.arg.template]p3:
6012 // A template-argument matches a template template-parameter (call it P)
6013 // when each of the template parameters in the template-parameter-list of
6014 // the template-argument's corresponding class template or alias template
6015 // (call it A) matches the corresponding template parameter in the
6016 // template-parameter-list of P. [...]
6017 TemplateParameterList::iterator NewParm = New->begin();
6018 TemplateParameterList::iterator NewParmEnd = New->end();
6019 for (TemplateParameterList::iterator OldParm = Old->begin(),
6020 OldParmEnd = Old->end();
6021 OldParm != OldParmEnd; ++OldParm) {
6022 if (Kind != TPL_TemplateTemplateArgumentMatch ||
6023 !(*OldParm)->isTemplateParameterPack()) {
6024 if (NewParm == NewParmEnd) {
6026 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
6032 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
6033 Kind, TemplateArgLoc))
6040 // C++0x [temp.arg.template]p3:
6041 // [...] When P's template- parameter-list contains a template parameter
6042 // pack (14.5.3), the template parameter pack will match zero or more
6043 // template parameters or template parameter packs in the
6044 // template-parameter-list of A with the same type and form as the
6045 // template parameter pack in P (ignoring whether those template
6046 // parameters are template parameter packs).
6047 for (; NewParm != NewParmEnd; ++NewParm) {
6048 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
6049 Kind, TemplateArgLoc))
6054 // Make sure we exhausted all of the arguments.
6055 if (NewParm != NewParmEnd) {
6057 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
6066 /// \brief Check whether a template can be declared within this scope.
6068 /// If the template declaration is valid in this scope, returns
6069 /// false. Otherwise, issues a diagnostic and returns true.
6071 Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) {
6075 // Find the nearest enclosing declaration scope.
6076 while ((S->getFlags() & Scope::DeclScope) == 0 ||
6077 (S->getFlags() & Scope::TemplateParamScope) != 0)
6081 // A template [...] shall not have C linkage.
6082 DeclContext *Ctx = S->getEntity();
6083 if (Ctx && Ctx->isExternCContext()) {
6084 Diag(TemplateParams->getTemplateLoc(), diag::err_template_linkage)
6085 << TemplateParams->getSourceRange();
6086 if (const LinkageSpecDecl *LSD = Ctx->getExternCContext())
6087 Diag(LSD->getExternLoc(), diag::note_extern_c_begins_here);
6090 Ctx = Ctx->getRedeclContext();
6093 // A template-declaration can appear only as a namespace scope or
6094 // class scope declaration.
6096 if (Ctx->isFileContext())
6098 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Ctx)) {
6099 // C++ [temp.mem]p2:
6100 // A local class shall not have member templates.
6101 if (RD->isLocalClass())
6102 return Diag(TemplateParams->getTemplateLoc(),
6103 diag::err_template_inside_local_class)
6104 << TemplateParams->getSourceRange();
6110 return Diag(TemplateParams->getTemplateLoc(),
6111 diag::err_template_outside_namespace_or_class_scope)
6112 << TemplateParams->getSourceRange();
6115 /// \brief Determine what kind of template specialization the given declaration
6117 static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D) {
6119 return TSK_Undeclared;
6121 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D))
6122 return Record->getTemplateSpecializationKind();
6123 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D))
6124 return Function->getTemplateSpecializationKind();
6125 if (VarDecl *Var = dyn_cast<VarDecl>(D))
6126 return Var->getTemplateSpecializationKind();
6128 return TSK_Undeclared;
6131 /// \brief Check whether a specialization is well-formed in the current
6134 /// This routine determines whether a template specialization can be declared
6135 /// in the current context (C++ [temp.expl.spec]p2).
6137 /// \param S the semantic analysis object for which this check is being
6140 /// \param Specialized the entity being specialized or instantiated, which
6141 /// may be a kind of template (class template, function template, etc.) or
6142 /// a member of a class template (member function, static data member,
6145 /// \param PrevDecl the previous declaration of this entity, if any.
6147 /// \param Loc the location of the explicit specialization or instantiation of
6150 /// \param IsPartialSpecialization whether this is a partial specialization of
6151 /// a class template.
6153 /// \returns true if there was an error that we cannot recover from, false
6155 static bool CheckTemplateSpecializationScope(Sema &S,
6156 NamedDecl *Specialized,
6157 NamedDecl *PrevDecl,
6159 bool IsPartialSpecialization) {
6160 // Keep these "kind" numbers in sync with the %select statements in the
6161 // various diagnostics emitted by this routine.
6163 if (isa<ClassTemplateDecl>(Specialized))
6164 EntityKind = IsPartialSpecialization? 1 : 0;
6165 else if (isa<VarTemplateDecl>(Specialized))
6166 EntityKind = IsPartialSpecialization ? 3 : 2;
6167 else if (isa<FunctionTemplateDecl>(Specialized))
6169 else if (isa<CXXMethodDecl>(Specialized))
6171 else if (isa<VarDecl>(Specialized))
6173 else if (isa<RecordDecl>(Specialized))
6175 else if (isa<EnumDecl>(Specialized) && S.getLangOpts().CPlusPlus11)
6178 S.Diag(Loc, diag::err_template_spec_unknown_kind)
6179 << S.getLangOpts().CPlusPlus11;
6180 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
6184 // C++ [temp.expl.spec]p2:
6185 // An explicit specialization shall be declared in the namespace
6186 // of which the template is a member, or, for member templates, in
6187 // the namespace of which the enclosing class or enclosing class
6188 // template is a member. An explicit specialization of a member
6189 // function, member class or static data member of a class
6190 // template shall be declared in the namespace of which the class
6191 // template is a member. Such a declaration may also be a
6192 // definition. If the declaration is not a definition, the
6193 // specialization may be defined later in the name- space in which
6194 // the explicit specialization was declared, or in a namespace
6195 // that encloses the one in which the explicit specialization was
6197 if (S.CurContext->getRedeclContext()->isFunctionOrMethod()) {
6198 S.Diag(Loc, diag::err_template_spec_decl_function_scope)
6203 if (S.CurContext->isRecord() && !IsPartialSpecialization) {
6204 if (S.getLangOpts().MicrosoftExt) {
6205 // Do not warn for class scope explicit specialization during
6206 // instantiation, warning was already emitted during pattern
6207 // semantic analysis.
6208 if (!S.ActiveTemplateInstantiations.size())
6209 S.Diag(Loc, diag::ext_function_specialization_in_class)
6212 S.Diag(Loc, diag::err_template_spec_decl_class_scope)
6218 if (S.CurContext->isRecord() &&
6219 !S.CurContext->Equals(Specialized->getDeclContext())) {
6220 // Make sure that we're specializing in the right record context.
6221 // Otherwise, things can go horribly wrong.
6222 S.Diag(Loc, diag::err_template_spec_decl_class_scope)
6227 // C++ [temp.class.spec]p6:
6228 // A class template partial specialization may be declared or redeclared
6229 // in any namespace scope in which its definition may be defined (14.5.1
6231 DeclContext *SpecializedContext
6232 = Specialized->getDeclContext()->getEnclosingNamespaceContext();
6233 DeclContext *DC = S.CurContext->getEnclosingNamespaceContext();
6235 // Make sure that this redeclaration (or definition) occurs in an enclosing
6237 // Note that HandleDeclarator() performs this check for explicit
6238 // specializations of function templates, static data members, and member
6239 // functions, so we skip the check here for those kinds of entities.
6240 // FIXME: HandleDeclarator's diagnostics aren't quite as good, though.
6241 // Should we refactor that check, so that it occurs later?
6242 if (!DC->Encloses(SpecializedContext) &&
6243 !(isa<FunctionTemplateDecl>(Specialized) ||
6244 isa<FunctionDecl>(Specialized) ||
6245 isa<VarTemplateDecl>(Specialized) ||
6246 isa<VarDecl>(Specialized))) {
6247 if (isa<TranslationUnitDecl>(SpecializedContext))
6248 S.Diag(Loc, diag::err_template_spec_redecl_global_scope)
6249 << EntityKind << Specialized;
6250 else if (isa<NamespaceDecl>(SpecializedContext)) {
6251 int Diag = diag::err_template_spec_redecl_out_of_scope;
6252 if (S.getLangOpts().MicrosoftExt)
6253 Diag = diag::ext_ms_template_spec_redecl_out_of_scope;
6254 S.Diag(Loc, Diag) << EntityKind << Specialized
6255 << cast<NamedDecl>(SpecializedContext);
6257 llvm_unreachable("unexpected namespace context for specialization");
6259 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
6260 } else if ((!PrevDecl ||
6261 getTemplateSpecializationKind(PrevDecl) == TSK_Undeclared ||
6262 getTemplateSpecializationKind(PrevDecl) ==
6263 TSK_ImplicitInstantiation)) {
6264 // C++ [temp.exp.spec]p2:
6265 // An explicit specialization shall be declared in the namespace of which
6266 // the template is a member, or, for member templates, in the namespace
6267 // of which the enclosing class or enclosing class template is a member.
6268 // An explicit specialization of a member function, member class or
6269 // static data member of a class template shall be declared in the
6270 // namespace of which the class template is a member.
6272 // C++11 [temp.expl.spec]p2:
6273 // An explicit specialization shall be declared in a namespace enclosing
6274 // the specialized template.
6275 // C++11 [temp.explicit]p3:
6276 // An explicit instantiation shall appear in an enclosing namespace of its
6278 if (!DC->InEnclosingNamespaceSetOf(SpecializedContext)) {
6279 bool IsCPlusPlus11Extension = DC->Encloses(SpecializedContext);
6280 if (isa<TranslationUnitDecl>(SpecializedContext)) {
6281 assert(!IsCPlusPlus11Extension &&
6282 "DC encloses TU but isn't in enclosing namespace set");
6283 S.Diag(Loc, diag::err_template_spec_decl_out_of_scope_global)
6284 << EntityKind << Specialized;
6285 } else if (isa<NamespaceDecl>(SpecializedContext)) {
6287 if (!IsCPlusPlus11Extension)
6288 Diag = diag::err_template_spec_decl_out_of_scope;
6289 else if (!S.getLangOpts().CPlusPlus11)
6290 Diag = diag::ext_template_spec_decl_out_of_scope;
6292 Diag = diag::warn_cxx98_compat_template_spec_decl_out_of_scope;
6294 << EntityKind << Specialized << cast<NamedDecl>(SpecializedContext);
6297 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
6304 static SourceRange findTemplateParameterInType(unsigned Depth, Expr *E) {
6305 if (!E->isTypeDependent())
6306 return SourceLocation();
6307 DependencyChecker Checker(Depth, /*IgnoreNonTypeDependent*/true);
6308 Checker.TraverseStmt(E);
6309 if (Checker.MatchLoc.isInvalid())
6310 return E->getSourceRange();
6311 return Checker.MatchLoc;
6314 static SourceRange findTemplateParameter(unsigned Depth, TypeLoc TL) {
6315 if (!TL.getType()->isDependentType())
6316 return SourceLocation();
6317 DependencyChecker Checker(Depth, /*IgnoreNonTypeDependent*/true);
6318 Checker.TraverseTypeLoc(TL);
6319 if (Checker.MatchLoc.isInvalid())
6320 return TL.getSourceRange();
6321 return Checker.MatchLoc;
6324 /// \brief Subroutine of Sema::CheckTemplatePartialSpecializationArgs
6325 /// that checks non-type template partial specialization arguments.
6326 static bool CheckNonTypeTemplatePartialSpecializationArgs(
6327 Sema &S, SourceLocation TemplateNameLoc, NonTypeTemplateParmDecl *Param,
6328 const TemplateArgument *Args, unsigned NumArgs, bool IsDefaultArgument) {
6329 for (unsigned I = 0; I != NumArgs; ++I) {
6330 if (Args[I].getKind() == TemplateArgument::Pack) {
6331 if (CheckNonTypeTemplatePartialSpecializationArgs(
6332 S, TemplateNameLoc, Param, Args[I].pack_begin(),
6333 Args[I].pack_size(), IsDefaultArgument))
6339 if (Args[I].getKind() != TemplateArgument::Expression)
6342 Expr *ArgExpr = Args[I].getAsExpr();
6344 // We can have a pack expansion of any of the bullets below.
6345 if (PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(ArgExpr))
6346 ArgExpr = Expansion->getPattern();
6348 // Strip off any implicit casts we added as part of type checking.
6349 while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
6350 ArgExpr = ICE->getSubExpr();
6352 // C++ [temp.class.spec]p8:
6353 // A non-type argument is non-specialized if it is the name of a
6354 // non-type parameter. All other non-type arguments are
6357 // Below, we check the two conditions that only apply to
6358 // specialized non-type arguments, so skip any non-specialized
6360 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ArgExpr))
6361 if (isa<NonTypeTemplateParmDecl>(DRE->getDecl()))
6364 // C++ [temp.class.spec]p9:
6365 // Within the argument list of a class template partial
6366 // specialization, the following restrictions apply:
6367 // -- A partially specialized non-type argument expression
6368 // shall not involve a template parameter of the partial
6369 // specialization except when the argument expression is a
6370 // simple identifier.
6371 // -- The type of a template parameter corresponding to a
6372 // specialized non-type argument shall not be dependent on a
6373 // parameter of the specialization.
6374 // DR1315 removes the first bullet, leaving an incoherent set of rules.
6375 // We implement a compromise between the original rules and DR1315:
6376 // -- A specialized non-type template argument shall not be
6377 // type-dependent and the corresponding template parameter
6378 // shall have a non-dependent type.
6379 SourceRange ParamUseRange =
6380 findTemplateParameterInType(Param->getDepth(), ArgExpr);
6381 if (ParamUseRange.isValid()) {
6382 if (IsDefaultArgument) {
6383 S.Diag(TemplateNameLoc,
6384 diag::err_dependent_non_type_arg_in_partial_spec);
6385 S.Diag(ParamUseRange.getBegin(),
6386 diag::note_dependent_non_type_default_arg_in_partial_spec)
6389 S.Diag(ParamUseRange.getBegin(),
6390 diag::err_dependent_non_type_arg_in_partial_spec)
6396 ParamUseRange = findTemplateParameter(
6397 Param->getDepth(), Param->getTypeSourceInfo()->getTypeLoc());
6398 if (ParamUseRange.isValid()) {
6399 S.Diag(IsDefaultArgument ? TemplateNameLoc : ArgExpr->getLocStart(),
6400 diag::err_dependent_typed_non_type_arg_in_partial_spec)
6401 << Param->getType();
6402 S.Diag(Param->getLocation(), diag::note_template_param_here)
6403 << (IsDefaultArgument ? ParamUseRange : SourceRange())
6412 /// \brief Check the non-type template arguments of a class template
6413 /// partial specialization according to C++ [temp.class.spec]p9.
6415 /// \param TemplateNameLoc the location of the template name.
6416 /// \param PrimaryTemplate the template parameters of the primary class
6418 /// \param NumExplicit the number of explicitly-specified template arguments.
6419 /// \param TemplateArgs the template arguments of the class template
6420 /// partial specialization.
6422 /// \returns \c true if there was an error, \c false otherwise.
6423 bool Sema::CheckTemplatePartialSpecializationArgs(
6424 SourceLocation TemplateNameLoc, TemplateDecl *PrimaryTemplate,
6425 unsigned NumExplicit, ArrayRef<TemplateArgument> TemplateArgs) {
6426 // We have to be conservative when checking a template in a dependent
6428 if (PrimaryTemplate->getDeclContext()->isDependentContext())
6431 TemplateParameterList *TemplateParams =
6432 PrimaryTemplate->getTemplateParameters();
6433 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
6434 NonTypeTemplateParmDecl *Param
6435 = dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(I));
6439 if (CheckNonTypeTemplatePartialSpecializationArgs(*this, TemplateNameLoc,
6440 Param, &TemplateArgs[I],
6441 1, I >= NumExplicit))
6449 Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec,
6451 SourceLocation KWLoc,
6452 SourceLocation ModulePrivateLoc,
6453 TemplateIdAnnotation &TemplateId,
6454 AttributeList *Attr,
6455 MultiTemplateParamsArg
6456 TemplateParameterLists,
6457 SkipBodyInfo *SkipBody) {
6458 assert(TUK != TUK_Reference && "References are not specializations");
6460 CXXScopeSpec &SS = TemplateId.SS;
6462 // NOTE: KWLoc is the location of the tag keyword. This will instead
6463 // store the location of the outermost template keyword in the declaration.
6464 SourceLocation TemplateKWLoc = TemplateParameterLists.size() > 0
6465 ? TemplateParameterLists[0]->getTemplateLoc() : KWLoc;
6466 SourceLocation TemplateNameLoc = TemplateId.TemplateNameLoc;
6467 SourceLocation LAngleLoc = TemplateId.LAngleLoc;
6468 SourceLocation RAngleLoc = TemplateId.RAngleLoc;
6470 // Find the class template we're specializing
6471 TemplateName Name = TemplateId.Template.get();
6472 ClassTemplateDecl *ClassTemplate
6473 = dyn_cast_or_null<ClassTemplateDecl>(Name.getAsTemplateDecl());
6475 if (!ClassTemplate) {
6476 Diag(TemplateNameLoc, diag::err_not_class_template_specialization)
6477 << (Name.getAsTemplateDecl() &&
6478 isa<TemplateTemplateParmDecl>(Name.getAsTemplateDecl()));
6482 bool isExplicitSpecialization = false;
6483 bool isPartialSpecialization = false;
6485 // Check the validity of the template headers that introduce this
6487 // FIXME: We probably shouldn't complain about these headers for
6488 // friend declarations.
6489 bool Invalid = false;
6490 TemplateParameterList *TemplateParams =
6491 MatchTemplateParametersToScopeSpecifier(
6492 KWLoc, TemplateNameLoc, SS, &TemplateId,
6493 TemplateParameterLists, TUK == TUK_Friend, isExplicitSpecialization,
6498 if (TemplateParams && TemplateParams->size() > 0) {
6499 isPartialSpecialization = true;
6501 if (TUK == TUK_Friend) {
6502 Diag(KWLoc, diag::err_partial_specialization_friend)
6503 << SourceRange(LAngleLoc, RAngleLoc);
6507 // C++ [temp.class.spec]p10:
6508 // The template parameter list of a specialization shall not
6509 // contain default template argument values.
6510 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
6511 Decl *Param = TemplateParams->getParam(I);
6512 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) {
6513 if (TTP->hasDefaultArgument()) {
6514 Diag(TTP->getDefaultArgumentLoc(),
6515 diag::err_default_arg_in_partial_spec);
6516 TTP->removeDefaultArgument();
6518 } else if (NonTypeTemplateParmDecl *NTTP
6519 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
6520 if (Expr *DefArg = NTTP->getDefaultArgument()) {
6521 Diag(NTTP->getDefaultArgumentLoc(),
6522 diag::err_default_arg_in_partial_spec)
6523 << DefArg->getSourceRange();
6524 NTTP->removeDefaultArgument();
6527 TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(Param);
6528 if (TTP->hasDefaultArgument()) {
6529 Diag(TTP->getDefaultArgument().getLocation(),
6530 diag::err_default_arg_in_partial_spec)
6531 << TTP->getDefaultArgument().getSourceRange();
6532 TTP->removeDefaultArgument();
6536 } else if (TemplateParams) {
6537 if (TUK == TUK_Friend)
6538 Diag(KWLoc, diag::err_template_spec_friend)
6539 << FixItHint::CreateRemoval(
6540 SourceRange(TemplateParams->getTemplateLoc(),
6541 TemplateParams->getRAngleLoc()))
6542 << SourceRange(LAngleLoc, RAngleLoc);
6544 isExplicitSpecialization = true;
6546 assert(TUK == TUK_Friend && "should have a 'template<>' for this decl");
6549 // Check that the specialization uses the same tag kind as the
6550 // original template.
6551 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
6552 assert(Kind != TTK_Enum && "Invalid enum tag in class template spec!");
6553 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
6554 Kind, TUK == TUK_Definition, KWLoc,
6555 ClassTemplate->getIdentifier())) {
6556 Diag(KWLoc, diag::err_use_with_wrong_tag)
6558 << FixItHint::CreateReplacement(KWLoc,
6559 ClassTemplate->getTemplatedDecl()->getKindName());
6560 Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
6561 diag::note_previous_use);
6562 Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
6565 // Translate the parser's template argument list in our AST format.
6566 TemplateArgumentListInfo TemplateArgs =
6567 makeTemplateArgumentListInfo(*this, TemplateId);
6569 // Check for unexpanded parameter packs in any of the template arguments.
6570 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
6571 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
6572 UPPC_PartialSpecialization))
6575 // Check that the template argument list is well-formed for this
6577 SmallVector<TemplateArgument, 4> Converted;
6578 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
6579 TemplateArgs, false, Converted))
6582 // Find the class template (partial) specialization declaration that
6583 // corresponds to these arguments.
6584 if (isPartialSpecialization) {
6585 if (CheckTemplatePartialSpecializationArgs(TemplateNameLoc, ClassTemplate,
6586 TemplateArgs.size(), Converted))
6589 // FIXME: Move this to CheckTemplatePartialSpecializationArgs so we
6590 // also do it during instantiation.
6591 bool InstantiationDependent;
6592 if (!Name.isDependent() &&
6593 !TemplateSpecializationType::anyDependentTemplateArguments(
6594 TemplateArgs.arguments(), InstantiationDependent)) {
6595 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
6596 << ClassTemplate->getDeclName();
6597 isPartialSpecialization = false;
6601 void *InsertPos = nullptr;
6602 ClassTemplateSpecializationDecl *PrevDecl = nullptr;
6604 if (isPartialSpecialization)
6605 // FIXME: Template parameter list matters, too
6606 PrevDecl = ClassTemplate->findPartialSpecialization(Converted, InsertPos);
6608 PrevDecl = ClassTemplate->findSpecialization(Converted, InsertPos);
6610 ClassTemplateSpecializationDecl *Specialization = nullptr;
6612 // Check whether we can declare a class template specialization in
6613 // the current scope.
6614 if (TUK != TUK_Friend &&
6615 CheckTemplateSpecializationScope(*this, ClassTemplate, PrevDecl,
6617 isPartialSpecialization))
6620 // The canonical type
6622 if (isPartialSpecialization) {
6623 // Build the canonical type that describes the converted template
6624 // arguments of the class template partial specialization.
6625 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
6626 CanonType = Context.getTemplateSpecializationType(CanonTemplate,
6629 if (Context.hasSameType(CanonType,
6630 ClassTemplate->getInjectedClassNameSpecialization())) {
6631 // C++ [temp.class.spec]p9b3:
6633 // -- The argument list of the specialization shall not be identical
6634 // to the implicit argument list of the primary template.
6636 // This rule has since been removed, because it's redundant given DR1495,
6637 // but we keep it because it produces better diagnostics and recovery.
6638 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
6639 << /*class template*/0 << (TUK == TUK_Definition)
6640 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
6641 return CheckClassTemplate(S, TagSpec, TUK, KWLoc, SS,
6642 ClassTemplate->getIdentifier(),
6646 AS_none, /*ModulePrivateLoc=*/SourceLocation(),
6647 /*FriendLoc*/SourceLocation(),
6648 TemplateParameterLists.size() - 1,
6649 TemplateParameterLists.data());
6652 // Create a new class template partial specialization declaration node.
6653 ClassTemplatePartialSpecializationDecl *PrevPartial
6654 = cast_or_null<ClassTemplatePartialSpecializationDecl>(PrevDecl);
6655 ClassTemplatePartialSpecializationDecl *Partial
6656 = ClassTemplatePartialSpecializationDecl::Create(Context, Kind,
6657 ClassTemplate->getDeclContext(),
6658 KWLoc, TemplateNameLoc,
6665 SetNestedNameSpecifier(Partial, SS);
6666 if (TemplateParameterLists.size() > 1 && SS.isSet()) {
6667 Partial->setTemplateParameterListsInfo(
6668 Context, TemplateParameterLists.drop_back(1));
6672 ClassTemplate->AddPartialSpecialization(Partial, InsertPos);
6673 Specialization = Partial;
6675 // If we are providing an explicit specialization of a member class
6676 // template specialization, make a note of that.
6677 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
6678 PrevPartial->setMemberSpecialization();
6680 CheckTemplatePartialSpecialization(Partial);
6682 // Create a new class template specialization declaration node for
6683 // this explicit specialization or friend declaration.
6685 = ClassTemplateSpecializationDecl::Create(Context, Kind,
6686 ClassTemplate->getDeclContext(),
6687 KWLoc, TemplateNameLoc,
6691 SetNestedNameSpecifier(Specialization, SS);
6692 if (TemplateParameterLists.size() > 0) {
6693 Specialization->setTemplateParameterListsInfo(Context,
6694 TemplateParameterLists);
6698 ClassTemplate->AddSpecialization(Specialization, InsertPos);
6700 if (CurContext->isDependentContext()) {
6701 // -fms-extensions permits specialization of nested classes without
6702 // fully specializing the outer class(es).
6703 assert(getLangOpts().MicrosoftExt &&
6704 "Only possible with -fms-extensions!");
6705 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
6706 CanonType = Context.getTemplateSpecializationType(
6707 CanonTemplate, Converted);
6709 CanonType = Context.getTypeDeclType(Specialization);
6713 // C++ [temp.expl.spec]p6:
6714 // If a template, a member template or the member of a class template is
6715 // explicitly specialized then that specialization shall be declared
6716 // before the first use of that specialization that would cause an implicit
6717 // instantiation to take place, in every translation unit in which such a
6718 // use occurs; no diagnostic is required.
6719 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
6721 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6722 // Is there any previous explicit specialization declaration?
6723 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
6730 SourceRange Range(TemplateNameLoc, RAngleLoc);
6731 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
6732 << Context.getTypeDeclType(Specialization) << Range;
6734 Diag(PrevDecl->getPointOfInstantiation(),
6735 diag::note_instantiation_required_here)
6736 << (PrevDecl->getTemplateSpecializationKind()
6737 != TSK_ImplicitInstantiation);
6742 // If this is not a friend, note that this is an explicit specialization.
6743 if (TUK != TUK_Friend)
6744 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
6746 // Check that this isn't a redefinition of this specialization.
6747 if (TUK == TUK_Definition) {
6748 RecordDecl *Def = Specialization->getDefinition();
6749 NamedDecl *Hidden = nullptr;
6750 if (Def && SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
6751 SkipBody->ShouldSkip = true;
6752 makeMergedDefinitionVisible(Hidden, KWLoc);
6753 // From here on out, treat this as just a redeclaration.
6754 TUK = TUK_Declaration;
6756 SourceRange Range(TemplateNameLoc, RAngleLoc);
6757 Diag(TemplateNameLoc, diag::err_redefinition) << Specialization << Range;
6758 Diag(Def->getLocation(), diag::note_previous_definition);
6759 Specialization->setInvalidDecl();
6765 ProcessDeclAttributeList(S, Specialization, Attr);
6767 // Add alignment attributes if necessary; these attributes are checked when
6768 // the ASTContext lays out the structure.
6769 if (TUK == TUK_Definition) {
6770 AddAlignmentAttributesForRecord(Specialization);
6771 AddMsStructLayoutForRecord(Specialization);
6774 if (ModulePrivateLoc.isValid())
6775 Diag(Specialization->getLocation(), diag::err_module_private_specialization)
6776 << (isPartialSpecialization? 1 : 0)
6777 << FixItHint::CreateRemoval(ModulePrivateLoc);
6779 // Build the fully-sugared type for this class template
6780 // specialization as the user wrote in the specialization
6781 // itself. This means that we'll pretty-print the type retrieved
6782 // from the specialization's declaration the way that the user
6783 // actually wrote the specialization, rather than formatting the
6784 // name based on the "canonical" representation used to store the
6785 // template arguments in the specialization.
6786 TypeSourceInfo *WrittenTy
6787 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
6788 TemplateArgs, CanonType);
6789 if (TUK != TUK_Friend) {
6790 Specialization->setTypeAsWritten(WrittenTy);
6791 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
6794 // C++ [temp.expl.spec]p9:
6795 // A template explicit specialization is in the scope of the
6796 // namespace in which the template was defined.
6798 // We actually implement this paragraph where we set the semantic
6799 // context (in the creation of the ClassTemplateSpecializationDecl),
6800 // but we also maintain the lexical context where the actual
6801 // definition occurs.
6802 Specialization->setLexicalDeclContext(CurContext);
6804 // We may be starting the definition of this specialization.
6805 if (TUK == TUK_Definition)
6806 Specialization->startDefinition();
6808 if (TUK == TUK_Friend) {
6809 FriendDecl *Friend = FriendDecl::Create(Context, CurContext,
6813 Friend->setAccess(AS_public);
6814 CurContext->addDecl(Friend);
6816 // Add the specialization into its lexical context, so that it can
6817 // be seen when iterating through the list of declarations in that
6818 // context. However, specializations are not found by name lookup.
6819 CurContext->addDecl(Specialization);
6821 return Specialization;
6824 Decl *Sema::ActOnTemplateDeclarator(Scope *S,
6825 MultiTemplateParamsArg TemplateParameterLists,
6827 Decl *NewDecl = HandleDeclarator(S, D, TemplateParameterLists);
6828 ActOnDocumentableDecl(NewDecl);
6832 /// \brief Strips various properties off an implicit instantiation
6833 /// that has just been explicitly specialized.
6834 static void StripImplicitInstantiation(NamedDecl *D) {
6835 D->dropAttr<DLLImportAttr>();
6836 D->dropAttr<DLLExportAttr>();
6838 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
6839 FD->setInlineSpecified(false);
6842 /// \brief Compute the diagnostic location for an explicit instantiation
6843 // declaration or definition.
6844 static SourceLocation DiagLocForExplicitInstantiation(
6845 NamedDecl* D, SourceLocation PointOfInstantiation) {
6846 // Explicit instantiations following a specialization have no effect and
6847 // hence no PointOfInstantiation. In that case, walk decl backwards
6848 // until a valid name loc is found.
6849 SourceLocation PrevDiagLoc = PointOfInstantiation;
6850 for (Decl *Prev = D; Prev && !PrevDiagLoc.isValid();
6851 Prev = Prev->getPreviousDecl()) {
6852 PrevDiagLoc = Prev->getLocation();
6854 assert(PrevDiagLoc.isValid() &&
6855 "Explicit instantiation without point of instantiation?");
6859 /// \brief Diagnose cases where we have an explicit template specialization
6860 /// before/after an explicit template instantiation, producing diagnostics
6861 /// for those cases where they are required and determining whether the
6862 /// new specialization/instantiation will have any effect.
6864 /// \param NewLoc the location of the new explicit specialization or
6867 /// \param NewTSK the kind of the new explicit specialization or instantiation.
6869 /// \param PrevDecl the previous declaration of the entity.
6871 /// \param PrevTSK the kind of the old explicit specialization or instantiatin.
6873 /// \param PrevPointOfInstantiation if valid, indicates where the previus
6874 /// declaration was instantiated (either implicitly or explicitly).
6876 /// \param HasNoEffect will be set to true to indicate that the new
6877 /// specialization or instantiation has no effect and should be ignored.
6879 /// \returns true if there was an error that should prevent the introduction of
6880 /// the new declaration into the AST, false otherwise.
6882 Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc,
6883 TemplateSpecializationKind NewTSK,
6884 NamedDecl *PrevDecl,
6885 TemplateSpecializationKind PrevTSK,
6886 SourceLocation PrevPointOfInstantiation,
6887 bool &HasNoEffect) {
6888 HasNoEffect = false;
6891 case TSK_Undeclared:
6892 case TSK_ImplicitInstantiation:
6894 (PrevTSK == TSK_Undeclared || PrevTSK == TSK_ImplicitInstantiation) &&
6895 "previous declaration must be implicit!");
6898 case TSK_ExplicitSpecialization:
6900 case TSK_Undeclared:
6901 case TSK_ExplicitSpecialization:
6902 // Okay, we're just specializing something that is either already
6903 // explicitly specialized or has merely been mentioned without any
6907 case TSK_ImplicitInstantiation:
6908 if (PrevPointOfInstantiation.isInvalid()) {
6909 // The declaration itself has not actually been instantiated, so it is
6910 // still okay to specialize it.
6911 StripImplicitInstantiation(PrevDecl);
6916 case TSK_ExplicitInstantiationDeclaration:
6917 case TSK_ExplicitInstantiationDefinition:
6918 assert((PrevTSK == TSK_ImplicitInstantiation ||
6919 PrevPointOfInstantiation.isValid()) &&
6920 "Explicit instantiation without point of instantiation?");
6922 // C++ [temp.expl.spec]p6:
6923 // If a template, a member template or the member of a class template
6924 // is explicitly specialized then that specialization shall be declared
6925 // before the first use of that specialization that would cause an
6926 // implicit instantiation to take place, in every translation unit in
6927 // which such a use occurs; no diagnostic is required.
6928 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6929 // Is there any previous explicit specialization declaration?
6930 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization)
6934 Diag(NewLoc, diag::err_specialization_after_instantiation)
6936 Diag(PrevPointOfInstantiation, diag::note_instantiation_required_here)
6937 << (PrevTSK != TSK_ImplicitInstantiation);
6942 case TSK_ExplicitInstantiationDeclaration:
6944 case TSK_ExplicitInstantiationDeclaration:
6945 // This explicit instantiation declaration is redundant (that's okay).
6949 case TSK_Undeclared:
6950 case TSK_ImplicitInstantiation:
6951 // We're explicitly instantiating something that may have already been
6952 // implicitly instantiated; that's fine.
6955 case TSK_ExplicitSpecialization:
6956 // C++0x [temp.explicit]p4:
6957 // For a given set of template parameters, if an explicit instantiation
6958 // of a template appears after a declaration of an explicit
6959 // specialization for that template, the explicit instantiation has no
6964 case TSK_ExplicitInstantiationDefinition:
6965 // C++0x [temp.explicit]p10:
6966 // If an entity is the subject of both an explicit instantiation
6967 // declaration and an explicit instantiation definition in the same
6968 // translation unit, the definition shall follow the declaration.
6970 diag::err_explicit_instantiation_declaration_after_definition);
6972 // Explicit instantiations following a specialization have no effect and
6973 // hence no PrevPointOfInstantiation. In that case, walk decl backwards
6974 // until a valid name loc is found.
6975 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
6976 diag::note_explicit_instantiation_definition_here);
6981 case TSK_ExplicitInstantiationDefinition:
6983 case TSK_Undeclared:
6984 case TSK_ImplicitInstantiation:
6985 // We're explicitly instantiating something that may have already been
6986 // implicitly instantiated; that's fine.
6989 case TSK_ExplicitSpecialization:
6990 // C++ DR 259, C++0x [temp.explicit]p4:
6991 // For a given set of template parameters, if an explicit
6992 // instantiation of a template appears after a declaration of
6993 // an explicit specialization for that template, the explicit
6994 // instantiation has no effect.
6995 Diag(NewLoc, diag::warn_explicit_instantiation_after_specialization)
6997 Diag(PrevDecl->getLocation(),
6998 diag::note_previous_template_specialization);
7002 case TSK_ExplicitInstantiationDeclaration:
7003 // We're explicity instantiating a definition for something for which we
7004 // were previously asked to suppress instantiations. That's fine.
7006 // C++0x [temp.explicit]p4:
7007 // For a given set of template parameters, if an explicit instantiation
7008 // of a template appears after a declaration of an explicit
7009 // specialization for that template, the explicit instantiation has no
7011 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
7012 // Is there any previous explicit specialization declaration?
7013 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
7021 case TSK_ExplicitInstantiationDefinition:
7022 // C++0x [temp.spec]p5:
7023 // For a given template and a given set of template-arguments,
7024 // - an explicit instantiation definition shall appear at most once
7027 // MSVCCompat: MSVC silently ignores duplicate explicit instantiations.
7028 Diag(NewLoc, (getLangOpts().MSVCCompat)
7029 ? diag::ext_explicit_instantiation_duplicate
7030 : diag::err_explicit_instantiation_duplicate)
7032 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
7033 diag::note_previous_explicit_instantiation);
7039 llvm_unreachable("Missing specialization/instantiation case?");
7042 /// \brief Perform semantic analysis for the given dependent function
7043 /// template specialization.
7045 /// The only possible way to get a dependent function template specialization
7046 /// is with a friend declaration, like so:
7049 /// template \<class T> void foo(T);
7050 /// template \<class T> class A {
7051 /// friend void foo<>(T);
7055 /// There really isn't any useful analysis we can do here, so we
7056 /// just store the information.
7058 Sema::CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD,
7059 const TemplateArgumentListInfo &ExplicitTemplateArgs,
7060 LookupResult &Previous) {
7061 // Remove anything from Previous that isn't a function template in
7062 // the correct context.
7063 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
7064 LookupResult::Filter F = Previous.makeFilter();
7065 while (F.hasNext()) {
7066 NamedDecl *D = F.next()->getUnderlyingDecl();
7067 if (!isa<FunctionTemplateDecl>(D) ||
7068 !FDLookupContext->InEnclosingNamespaceSetOf(
7069 D->getDeclContext()->getRedeclContext()))
7074 // Should this be diagnosed here?
7075 if (Previous.empty()) return true;
7077 FD->setDependentTemplateSpecialization(Context, Previous.asUnresolvedSet(),
7078 ExplicitTemplateArgs);
7082 /// \brief Perform semantic analysis for the given function template
7085 /// This routine performs all of the semantic analysis required for an
7086 /// explicit function template specialization. On successful completion,
7087 /// the function declaration \p FD will become a function template
7090 /// \param FD the function declaration, which will be updated to become a
7091 /// function template specialization.
7093 /// \param ExplicitTemplateArgs the explicitly-provided template arguments,
7094 /// if any. Note that this may be valid info even when 0 arguments are
7095 /// explicitly provided as in, e.g., \c void sort<>(char*, char*);
7096 /// as it anyway contains info on the angle brackets locations.
7098 /// \param Previous the set of declarations that may be specialized by
7099 /// this function specialization.
7100 bool Sema::CheckFunctionTemplateSpecialization(
7101 FunctionDecl *FD, TemplateArgumentListInfo *ExplicitTemplateArgs,
7102 LookupResult &Previous) {
7103 // The set of function template specializations that could match this
7104 // explicit function template specialization.
7105 UnresolvedSet<8> Candidates;
7106 TemplateSpecCandidateSet FailedCandidates(FD->getLocation(),
7107 /*ForTakingAddress=*/false);
7109 llvm::SmallDenseMap<FunctionDecl *, TemplateArgumentListInfo, 8>
7110 ConvertedTemplateArgs;
7112 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
7113 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
7115 NamedDecl *Ovl = (*I)->getUnderlyingDecl();
7116 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Ovl)) {
7117 // Only consider templates found within the same semantic lookup scope as
7119 if (!FDLookupContext->InEnclosingNamespaceSetOf(
7120 Ovl->getDeclContext()->getRedeclContext()))
7123 // When matching a constexpr member function template specialization
7124 // against the primary template, we don't yet know whether the
7125 // specialization has an implicit 'const' (because we don't know whether
7126 // it will be a static member function until we know which template it
7127 // specializes), so adjust it now assuming it specializes this template.
7128 QualType FT = FD->getType();
7129 if (FD->isConstexpr()) {
7130 CXXMethodDecl *OldMD =
7131 dyn_cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl());
7132 if (OldMD && OldMD->isConst()) {
7133 const FunctionProtoType *FPT = FT->castAs<FunctionProtoType>();
7134 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
7135 EPI.TypeQuals |= Qualifiers::Const;
7136 FT = Context.getFunctionType(FPT->getReturnType(),
7137 FPT->getParamTypes(), EPI);
7141 TemplateArgumentListInfo Args;
7142 if (ExplicitTemplateArgs)
7143 Args = *ExplicitTemplateArgs;
7145 // C++ [temp.expl.spec]p11:
7146 // A trailing template-argument can be left unspecified in the
7147 // template-id naming an explicit function template specialization
7148 // provided it can be deduced from the function argument type.
7149 // Perform template argument deduction to determine whether we may be
7150 // specializing this template.
7151 // FIXME: It is somewhat wasteful to build
7152 TemplateDeductionInfo Info(FailedCandidates.getLocation());
7153 FunctionDecl *Specialization = nullptr;
7154 if (TemplateDeductionResult TDK = DeduceTemplateArguments(
7155 cast<FunctionTemplateDecl>(FunTmpl->getFirstDecl()),
7156 ExplicitTemplateArgs ? &Args : nullptr, FT, Specialization,
7158 // Template argument deduction failed; record why it failed, so
7159 // that we can provide nifty diagnostics.
7160 FailedCandidates.addCandidate().set(
7161 I.getPair(), FunTmpl->getTemplatedDecl(),
7162 MakeDeductionFailureInfo(Context, TDK, Info));
7167 // Target attributes are part of the cuda function signature, so
7168 // the deduced template's cuda target must match that of the
7169 // specialization. Given that C++ template deduction does not
7170 // take target attributes into account, we reject candidates
7171 // here that have a different target.
7172 if (LangOpts.CUDA &&
7173 IdentifyCUDATarget(Specialization,
7174 /* IgnoreImplicitHDAttributes = */ true) !=
7175 IdentifyCUDATarget(FD, /* IgnoreImplicitHDAttributes = */ true)) {
7176 FailedCandidates.addCandidate().set(
7177 I.getPair(), FunTmpl->getTemplatedDecl(),
7178 MakeDeductionFailureInfo(Context, TDK_CUDATargetMismatch, Info));
7182 // Record this candidate.
7183 if (ExplicitTemplateArgs)
7184 ConvertedTemplateArgs[Specialization] = std::move(Args);
7185 Candidates.addDecl(Specialization, I.getAccess());
7189 // Find the most specialized function template.
7190 UnresolvedSetIterator Result = getMostSpecialized(
7191 Candidates.begin(), Candidates.end(), FailedCandidates,
7193 PDiag(diag::err_function_template_spec_no_match) << FD->getDeclName(),
7194 PDiag(diag::err_function_template_spec_ambiguous)
7195 << FD->getDeclName() << (ExplicitTemplateArgs != nullptr),
7196 PDiag(diag::note_function_template_spec_matched));
7198 if (Result == Candidates.end())
7201 // Ignore access information; it doesn't figure into redeclaration checking.
7202 FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
7204 // C++ Concepts TS [dcl.spec.concept]p7: A program shall not declare [...]
7205 // an explicit specialization (14.8.3) [...] of a concept definition.
7206 if (Specialization->getPrimaryTemplate()->isConcept()) {
7207 Diag(FD->getLocation(), diag::err_concept_specialized)
7208 << 0 /*function*/ << 1 /*explicitly specialized*/;
7209 Diag(Specialization->getLocation(), diag::note_previous_declaration);
7213 FunctionTemplateSpecializationInfo *SpecInfo
7214 = Specialization->getTemplateSpecializationInfo();
7215 assert(SpecInfo && "Function template specialization info missing?");
7217 // Note: do not overwrite location info if previous template
7218 // specialization kind was explicit.
7219 TemplateSpecializationKind TSK = SpecInfo->getTemplateSpecializationKind();
7220 if (TSK == TSK_Undeclared || TSK == TSK_ImplicitInstantiation) {
7221 Specialization->setLocation(FD->getLocation());
7222 // C++11 [dcl.constexpr]p1: An explicit specialization of a constexpr
7223 // function can differ from the template declaration with respect to
7224 // the constexpr specifier.
7225 Specialization->setConstexpr(FD->isConstexpr());
7228 // FIXME: Check if the prior specialization has a point of instantiation.
7229 // If so, we have run afoul of .
7231 // If this is a friend declaration, then we're not really declaring
7232 // an explicit specialization.
7233 bool isFriend = (FD->getFriendObjectKind() != Decl::FOK_None);
7235 // Check the scope of this explicit specialization.
7237 CheckTemplateSpecializationScope(*this,
7238 Specialization->getPrimaryTemplate(),
7239 Specialization, FD->getLocation(),
7243 // C++ [temp.expl.spec]p6:
7244 // If a template, a member template or the member of a class template is
7245 // explicitly specialized then that specialization shall be declared
7246 // before the first use of that specialization that would cause an implicit
7247 // instantiation to take place, in every translation unit in which such a
7248 // use occurs; no diagnostic is required.
7249 bool HasNoEffect = false;
7251 CheckSpecializationInstantiationRedecl(FD->getLocation(),
7252 TSK_ExplicitSpecialization,
7254 SpecInfo->getTemplateSpecializationKind(),
7255 SpecInfo->getPointOfInstantiation(),
7259 // Mark the prior declaration as an explicit specialization, so that later
7260 // clients know that this is an explicit specialization.
7262 // Since explicit specializations do not inherit '=delete' from their
7263 // primary function template - check if the 'specialization' that was
7264 // implicitly generated (during template argument deduction for partial
7265 // ordering) from the most specialized of all the function templates that
7266 // 'FD' could have been specializing, has a 'deleted' definition. If so,
7267 // first check that it was implicitly generated during template argument
7268 // deduction by making sure it wasn't referenced, and then reset the deleted
7269 // flag to not-deleted, so that we can inherit that information from 'FD'.
7270 if (Specialization->isDeleted() && !SpecInfo->isExplicitSpecialization() &&
7271 !Specialization->getCanonicalDecl()->isReferenced()) {
7273 Specialization->getCanonicalDecl() == Specialization &&
7274 "This must be the only existing declaration of this specialization");
7275 Specialization->setDeletedAsWritten(false);
7277 SpecInfo->setTemplateSpecializationKind(TSK_ExplicitSpecialization);
7278 MarkUnusedFileScopedDecl(Specialization);
7281 // Turn the given function declaration into a function template
7282 // specialization, with the template arguments from the previous
7284 // Take copies of (semantic and syntactic) template argument lists.
7285 const TemplateArgumentList* TemplArgs = new (Context)
7286 TemplateArgumentList(Specialization->getTemplateSpecializationArgs());
7287 FD->setFunctionTemplateSpecialization(
7288 Specialization->getPrimaryTemplate(), TemplArgs, /*InsertPos=*/nullptr,
7289 SpecInfo->getTemplateSpecializationKind(),
7290 ExplicitTemplateArgs ? &ConvertedTemplateArgs[Specialization] : nullptr);
7292 // A function template specialization inherits the target attributes
7293 // of its template. (We require the attributes explicitly in the
7294 // code to match, but a template may have implicit attributes by
7295 // virtue e.g. of being constexpr, and it passes these implicit
7296 // attributes on to its specializations.)
7298 inheritCUDATargetAttrs(FD, *Specialization->getPrimaryTemplate());
7300 // The "previous declaration" for this function template specialization is
7301 // the prior function template specialization.
7303 Previous.addDecl(Specialization);
7307 /// \brief Perform semantic analysis for the given non-template member
7310 /// This routine performs all of the semantic analysis required for an
7311 /// explicit member function specialization. On successful completion,
7312 /// the function declaration \p FD will become a member function
7315 /// \param Member the member declaration, which will be updated to become a
7318 /// \param Previous the set of declarations, one of which may be specialized
7319 /// by this function specialization; the set will be modified to contain the
7320 /// redeclared member.
7322 Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
7323 assert(!isa<TemplateDecl>(Member) && "Only for non-template members");
7325 // Try to find the member we are instantiating.
7326 NamedDecl *FoundInstantiation = nullptr;
7327 NamedDecl *Instantiation = nullptr;
7328 NamedDecl *InstantiatedFrom = nullptr;
7329 MemberSpecializationInfo *MSInfo = nullptr;
7331 if (Previous.empty()) {
7332 // Nowhere to look anyway.
7333 } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Member)) {
7334 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
7336 NamedDecl *D = (*I)->getUnderlyingDecl();
7337 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
7338 QualType Adjusted = Function->getType();
7339 if (!hasExplicitCallingConv(Adjusted))
7340 Adjusted = adjustCCAndNoReturn(Adjusted, Method->getType());
7341 if (Context.hasSameType(Adjusted, Method->getType())) {
7342 FoundInstantiation = *I;
7343 Instantiation = Method;
7344 InstantiatedFrom = Method->getInstantiatedFromMemberFunction();
7345 MSInfo = Method->getMemberSpecializationInfo();
7350 } else if (isa<VarDecl>(Member)) {
7352 if (Previous.isSingleResult() &&
7353 (PrevVar = dyn_cast<VarDecl>(Previous.getFoundDecl())))
7354 if (PrevVar->isStaticDataMember()) {
7355 FoundInstantiation = Previous.getRepresentativeDecl();
7356 Instantiation = PrevVar;
7357 InstantiatedFrom = PrevVar->getInstantiatedFromStaticDataMember();
7358 MSInfo = PrevVar->getMemberSpecializationInfo();
7360 } else if (isa<RecordDecl>(Member)) {
7361 CXXRecordDecl *PrevRecord;
7362 if (Previous.isSingleResult() &&
7363 (PrevRecord = dyn_cast<CXXRecordDecl>(Previous.getFoundDecl()))) {
7364 FoundInstantiation = Previous.getRepresentativeDecl();
7365 Instantiation = PrevRecord;
7366 InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass();
7367 MSInfo = PrevRecord->getMemberSpecializationInfo();
7369 } else if (isa<EnumDecl>(Member)) {
7371 if (Previous.isSingleResult() &&
7372 (PrevEnum = dyn_cast<EnumDecl>(Previous.getFoundDecl()))) {
7373 FoundInstantiation = Previous.getRepresentativeDecl();
7374 Instantiation = PrevEnum;
7375 InstantiatedFrom = PrevEnum->getInstantiatedFromMemberEnum();
7376 MSInfo = PrevEnum->getMemberSpecializationInfo();
7380 if (!Instantiation) {
7381 // There is no previous declaration that matches. Since member
7382 // specializations are always out-of-line, the caller will complain about
7383 // this mismatch later.
7387 // If this is a friend, just bail out here before we start turning
7388 // things into explicit specializations.
7389 if (Member->getFriendObjectKind() != Decl::FOK_None) {
7390 // Preserve instantiation information.
7391 if (InstantiatedFrom && isa<CXXMethodDecl>(Member)) {
7392 cast<CXXMethodDecl>(Member)->setInstantiationOfMemberFunction(
7393 cast<CXXMethodDecl>(InstantiatedFrom),
7394 cast<CXXMethodDecl>(Instantiation)->getTemplateSpecializationKind());
7395 } else if (InstantiatedFrom && isa<CXXRecordDecl>(Member)) {
7396 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
7397 cast<CXXRecordDecl>(InstantiatedFrom),
7398 cast<CXXRecordDecl>(Instantiation)->getTemplateSpecializationKind());
7402 Previous.addDecl(FoundInstantiation);
7406 // Make sure that this is a specialization of a member.
7407 if (!InstantiatedFrom) {
7408 Diag(Member->getLocation(), diag::err_spec_member_not_instantiated)
7410 Diag(Instantiation->getLocation(), diag::note_specialized_decl);
7414 // C++ [temp.expl.spec]p6:
7415 // If a template, a member template or the member of a class template is
7416 // explicitly specialized then that specialization shall be declared
7417 // before the first use of that specialization that would cause an implicit
7418 // instantiation to take place, in every translation unit in which such a
7419 // use occurs; no diagnostic is required.
7420 assert(MSInfo && "Member specialization info missing?");
7422 bool HasNoEffect = false;
7423 if (CheckSpecializationInstantiationRedecl(Member->getLocation(),
7424 TSK_ExplicitSpecialization,
7426 MSInfo->getTemplateSpecializationKind(),
7427 MSInfo->getPointOfInstantiation(),
7431 // Check the scope of this explicit specialization.
7432 if (CheckTemplateSpecializationScope(*this,
7434 Instantiation, Member->getLocation(),
7438 // Note that this is an explicit instantiation of a member.
7439 // the original declaration to note that it is an explicit specialization
7440 // (if it was previously an implicit instantiation). This latter step
7441 // makes bookkeeping easier.
7442 if (isa<FunctionDecl>(Member)) {
7443 FunctionDecl *InstantiationFunction = cast<FunctionDecl>(Instantiation);
7444 if (InstantiationFunction->getTemplateSpecializationKind() ==
7445 TSK_ImplicitInstantiation) {
7446 InstantiationFunction->setTemplateSpecializationKind(
7447 TSK_ExplicitSpecialization);
7448 InstantiationFunction->setLocation(Member->getLocation());
7449 // Explicit specializations of member functions of class templates do not
7450 // inherit '=delete' from the member function they are specializing.
7451 if (InstantiationFunction->isDeleted()) {
7452 assert(InstantiationFunction->getCanonicalDecl() ==
7453 InstantiationFunction);
7454 InstantiationFunction->setDeletedAsWritten(false);
7458 cast<FunctionDecl>(Member)->setInstantiationOfMemberFunction(
7459 cast<CXXMethodDecl>(InstantiatedFrom),
7460 TSK_ExplicitSpecialization);
7461 MarkUnusedFileScopedDecl(InstantiationFunction);
7462 } else if (isa<VarDecl>(Member)) {
7463 VarDecl *InstantiationVar = cast<VarDecl>(Instantiation);
7464 if (InstantiationVar->getTemplateSpecializationKind() ==
7465 TSK_ImplicitInstantiation) {
7466 InstantiationVar->setTemplateSpecializationKind(
7467 TSK_ExplicitSpecialization);
7468 InstantiationVar->setLocation(Member->getLocation());
7471 cast<VarDecl>(Member)->setInstantiationOfStaticDataMember(
7472 cast<VarDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
7473 MarkUnusedFileScopedDecl(InstantiationVar);
7474 } else if (isa<CXXRecordDecl>(Member)) {
7475 CXXRecordDecl *InstantiationClass = cast<CXXRecordDecl>(Instantiation);
7476 if (InstantiationClass->getTemplateSpecializationKind() ==
7477 TSK_ImplicitInstantiation) {
7478 InstantiationClass->setTemplateSpecializationKind(
7479 TSK_ExplicitSpecialization);
7480 InstantiationClass->setLocation(Member->getLocation());
7483 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
7484 cast<CXXRecordDecl>(InstantiatedFrom),
7485 TSK_ExplicitSpecialization);
7487 assert(isa<EnumDecl>(Member) && "Only member enums remain");
7488 EnumDecl *InstantiationEnum = cast<EnumDecl>(Instantiation);
7489 if (InstantiationEnum->getTemplateSpecializationKind() ==
7490 TSK_ImplicitInstantiation) {
7491 InstantiationEnum->setTemplateSpecializationKind(
7492 TSK_ExplicitSpecialization);
7493 InstantiationEnum->setLocation(Member->getLocation());
7496 cast<EnumDecl>(Member)->setInstantiationOfMemberEnum(
7497 cast<EnumDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
7500 // Save the caller the trouble of having to figure out which declaration
7501 // this specialization matches.
7503 Previous.addDecl(FoundInstantiation);
7507 /// \brief Check the scope of an explicit instantiation.
7509 /// \returns true if a serious error occurs, false otherwise.
7510 static bool CheckExplicitInstantiationScope(Sema &S, NamedDecl *D,
7511 SourceLocation InstLoc,
7512 bool WasQualifiedName) {
7513 DeclContext *OrigContext= D->getDeclContext()->getEnclosingNamespaceContext();
7514 DeclContext *CurContext = S.CurContext->getRedeclContext();
7516 if (CurContext->isRecord()) {
7517 S.Diag(InstLoc, diag::err_explicit_instantiation_in_class)
7522 // C++11 [temp.explicit]p3:
7523 // An explicit instantiation shall appear in an enclosing namespace of its
7524 // template. If the name declared in the explicit instantiation is an
7525 // unqualified name, the explicit instantiation shall appear in the
7526 // namespace where its template is declared or, if that namespace is inline
7527 // (7.3.1), any namespace from its enclosing namespace set.
7529 // This is DR275, which we do not retroactively apply to C++98/03.
7530 if (WasQualifiedName) {
7531 if (CurContext->Encloses(OrigContext))
7534 if (CurContext->InEnclosingNamespaceSetOf(OrigContext))
7538 if (NamespaceDecl *NS = dyn_cast<NamespaceDecl>(OrigContext)) {
7539 if (WasQualifiedName)
7541 S.getLangOpts().CPlusPlus11?
7542 diag::err_explicit_instantiation_out_of_scope :
7543 diag::warn_explicit_instantiation_out_of_scope_0x)
7547 S.getLangOpts().CPlusPlus11?
7548 diag::err_explicit_instantiation_unqualified_wrong_namespace :
7549 diag::warn_explicit_instantiation_unqualified_wrong_namespace_0x)
7553 S.getLangOpts().CPlusPlus11?
7554 diag::err_explicit_instantiation_must_be_global :
7555 diag::warn_explicit_instantiation_must_be_global_0x)
7557 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here);
7561 /// \brief Determine whether the given scope specifier has a template-id in it.
7562 static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec &SS) {
7566 // C++11 [temp.explicit]p3:
7567 // If the explicit instantiation is for a member function, a member class
7568 // or a static data member of a class template specialization, the name of
7569 // the class template specialization in the qualified-id for the member
7570 // name shall be a simple-template-id.
7572 // C++98 has the same restriction, just worded differently.
7573 for (NestedNameSpecifier *NNS = SS.getScopeRep(); NNS;
7574 NNS = NNS->getPrefix())
7575 if (const Type *T = NNS->getAsType())
7576 if (isa<TemplateSpecializationType>(T))
7582 /// Make a dllexport or dllimport attr on a class template specialization take
7584 static void dllExportImportClassTemplateSpecialization(
7585 Sema &S, ClassTemplateSpecializationDecl *Def) {
7586 auto *A = cast_or_null<InheritableAttr>(getDLLAttr(Def));
7587 assert(A && "dllExportImportClassTemplateSpecialization called "
7588 "on Def without dllexport or dllimport");
7590 // We reject explicit instantiations in class scope, so there should
7591 // never be any delayed exported classes to worry about.
7592 assert(S.DelayedDllExportClasses.empty() &&
7593 "delayed exports present at explicit instantiation");
7594 S.checkClassLevelDLLAttribute(Def);
7596 // Propagate attribute to base class templates.
7597 for (auto &B : Def->bases()) {
7598 if (auto *BT = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
7599 B.getType()->getAsCXXRecordDecl()))
7600 S.propagateDLLAttrToBaseClassTemplate(Def, A, BT, B.getLocStart());
7603 S.referenceDLLExportedClassMethods();
7606 // Explicit instantiation of a class template specialization
7608 Sema::ActOnExplicitInstantiation(Scope *S,
7609 SourceLocation ExternLoc,
7610 SourceLocation TemplateLoc,
7612 SourceLocation KWLoc,
7613 const CXXScopeSpec &SS,
7614 TemplateTy TemplateD,
7615 SourceLocation TemplateNameLoc,
7616 SourceLocation LAngleLoc,
7617 ASTTemplateArgsPtr TemplateArgsIn,
7618 SourceLocation RAngleLoc,
7619 AttributeList *Attr) {
7620 // Find the class template we're specializing
7621 TemplateName Name = TemplateD.get();
7622 TemplateDecl *TD = Name.getAsTemplateDecl();
7623 // Check that the specialization uses the same tag kind as the
7624 // original template.
7625 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
7626 assert(Kind != TTK_Enum &&
7627 "Invalid enum tag in class template explicit instantiation!");
7629 ClassTemplateDecl *ClassTemplate = dyn_cast<ClassTemplateDecl>(TD);
7631 if (!ClassTemplate) {
7632 NonTagKind NTK = getNonTagTypeDeclKind(TD, Kind);
7633 Diag(TemplateNameLoc, diag::err_tag_reference_non_tag) << TD << NTK << Kind;
7634 Diag(TD->getLocation(), diag::note_previous_use);
7638 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
7639 Kind, /*isDefinition*/false, KWLoc,
7640 ClassTemplate->getIdentifier())) {
7641 Diag(KWLoc, diag::err_use_with_wrong_tag)
7643 << FixItHint::CreateReplacement(KWLoc,
7644 ClassTemplate->getTemplatedDecl()->getKindName());
7645 Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
7646 diag::note_previous_use);
7647 Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
7650 // C++0x [temp.explicit]p2:
7651 // There are two forms of explicit instantiation: an explicit instantiation
7652 // definition and an explicit instantiation declaration. An explicit
7653 // instantiation declaration begins with the extern keyword. [...]
7654 TemplateSpecializationKind TSK = ExternLoc.isInvalid()
7655 ? TSK_ExplicitInstantiationDefinition
7656 : TSK_ExplicitInstantiationDeclaration;
7658 if (TSK == TSK_ExplicitInstantiationDeclaration) {
7659 // Check for dllexport class template instantiation declarations.
7660 for (AttributeList *A = Attr; A; A = A->getNext()) {
7661 if (A->getKind() == AttributeList::AT_DLLExport) {
7663 diag::warn_attribute_dllexport_explicit_instantiation_decl);
7664 Diag(A->getLoc(), diag::note_attribute);
7669 if (auto *A = ClassTemplate->getTemplatedDecl()->getAttr<DLLExportAttr>()) {
7671 diag::warn_attribute_dllexport_explicit_instantiation_decl);
7672 Diag(A->getLocation(), diag::note_attribute);
7676 // In MSVC mode, dllimported explicit instantiation definitions are treated as
7677 // instantiation declarations for most purposes.
7678 bool DLLImportExplicitInstantiationDef = false;
7679 if (TSK == TSK_ExplicitInstantiationDefinition &&
7680 Context.getTargetInfo().getCXXABI().isMicrosoft()) {
7681 // Check for dllimport class template instantiation definitions.
7683 ClassTemplate->getTemplatedDecl()->getAttr<DLLImportAttr>();
7684 for (AttributeList *A = Attr; A; A = A->getNext()) {
7685 if (A->getKind() == AttributeList::AT_DLLImport)
7687 if (A->getKind() == AttributeList::AT_DLLExport) {
7688 // dllexport trumps dllimport here.
7694 TSK = TSK_ExplicitInstantiationDeclaration;
7695 DLLImportExplicitInstantiationDef = true;
7699 // Translate the parser's template argument list in our AST format.
7700 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
7701 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
7703 // Check that the template argument list is well-formed for this
7705 SmallVector<TemplateArgument, 4> Converted;
7706 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
7707 TemplateArgs, false, Converted))
7710 // Find the class template specialization declaration that
7711 // corresponds to these arguments.
7712 void *InsertPos = nullptr;
7713 ClassTemplateSpecializationDecl *PrevDecl
7714 = ClassTemplate->findSpecialization(Converted, InsertPos);
7716 TemplateSpecializationKind PrevDecl_TSK
7717 = PrevDecl ? PrevDecl->getTemplateSpecializationKind() : TSK_Undeclared;
7719 // C++0x [temp.explicit]p2:
7720 // [...] An explicit instantiation shall appear in an enclosing
7721 // namespace of its template. [...]
7723 // This is C++ DR 275.
7724 if (CheckExplicitInstantiationScope(*this, ClassTemplate, TemplateNameLoc,
7728 ClassTemplateSpecializationDecl *Specialization = nullptr;
7730 bool HasNoEffect = false;
7732 if (CheckSpecializationInstantiationRedecl(TemplateNameLoc, TSK,
7733 PrevDecl, PrevDecl_TSK,
7734 PrevDecl->getPointOfInstantiation(),
7738 // Even though HasNoEffect == true means that this explicit instantiation
7739 // has no effect on semantics, we go on to put its syntax in the AST.
7741 if (PrevDecl_TSK == TSK_ImplicitInstantiation ||
7742 PrevDecl_TSK == TSK_Undeclared) {
7743 // Since the only prior class template specialization with these
7744 // arguments was referenced but not declared, reuse that
7745 // declaration node as our own, updating the source location
7746 // for the template name to reflect our new declaration.
7747 // (Other source locations will be updated later.)
7748 Specialization = PrevDecl;
7749 Specialization->setLocation(TemplateNameLoc);
7753 if (PrevDecl_TSK == TSK_ExplicitInstantiationDeclaration &&
7754 DLLImportExplicitInstantiationDef) {
7755 // The new specialization might add a dllimport attribute.
7756 HasNoEffect = false;
7760 if (!Specialization) {
7761 // Create a new class template specialization declaration node for
7762 // this explicit specialization.
7764 = ClassTemplateSpecializationDecl::Create(Context, Kind,
7765 ClassTemplate->getDeclContext(),
7766 KWLoc, TemplateNameLoc,
7770 SetNestedNameSpecifier(Specialization, SS);
7772 if (!HasNoEffect && !PrevDecl) {
7773 // Insert the new specialization.
7774 ClassTemplate->AddSpecialization(Specialization, InsertPos);
7778 // Build the fully-sugared type for this explicit instantiation as
7779 // the user wrote in the explicit instantiation itself. This means
7780 // that we'll pretty-print the type retrieved from the
7781 // specialization's declaration the way that the user actually wrote
7782 // the explicit instantiation, rather than formatting the name based
7783 // on the "canonical" representation used to store the template
7784 // arguments in the specialization.
7785 TypeSourceInfo *WrittenTy
7786 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
7788 Context.getTypeDeclType(Specialization));
7789 Specialization->setTypeAsWritten(WrittenTy);
7791 // Set source locations for keywords.
7792 Specialization->setExternLoc(ExternLoc);
7793 Specialization->setTemplateKeywordLoc(TemplateLoc);
7794 Specialization->setBraceRange(SourceRange());
7796 bool PreviouslyDLLExported = Specialization->hasAttr<DLLExportAttr>();
7798 ProcessDeclAttributeList(S, Specialization, Attr);
7800 // Add the explicit instantiation into its lexical context. However,
7801 // since explicit instantiations are never found by name lookup, we
7802 // just put it into the declaration context directly.
7803 Specialization->setLexicalDeclContext(CurContext);
7804 CurContext->addDecl(Specialization);
7806 // Syntax is now OK, so return if it has no other effect on semantics.
7808 // Set the template specialization kind.
7809 Specialization->setTemplateSpecializationKind(TSK);
7810 return Specialization;
7813 // C++ [temp.explicit]p3:
7814 // A definition of a class template or class member template
7815 // shall be in scope at the point of the explicit instantiation of
7816 // the class template or class member template.
7818 // This check comes when we actually try to perform the
7820 ClassTemplateSpecializationDecl *Def
7821 = cast_or_null<ClassTemplateSpecializationDecl>(
7822 Specialization->getDefinition());
7824 InstantiateClassTemplateSpecialization(TemplateNameLoc, Specialization, TSK);
7825 else if (TSK == TSK_ExplicitInstantiationDefinition) {
7826 MarkVTableUsed(TemplateNameLoc, Specialization, true);
7827 Specialization->setPointOfInstantiation(Def->getPointOfInstantiation());
7830 // Instantiate the members of this class template specialization.
7831 Def = cast_or_null<ClassTemplateSpecializationDecl>(
7832 Specialization->getDefinition());
7834 TemplateSpecializationKind Old_TSK = Def->getTemplateSpecializationKind();
7835 // Fix a TSK_ExplicitInstantiationDeclaration followed by a
7836 // TSK_ExplicitInstantiationDefinition
7837 if (Old_TSK == TSK_ExplicitInstantiationDeclaration &&
7838 (TSK == TSK_ExplicitInstantiationDefinition ||
7839 DLLImportExplicitInstantiationDef)) {
7840 // FIXME: Need to notify the ASTMutationListener that we did this.
7841 Def->setTemplateSpecializationKind(TSK);
7843 if (!getDLLAttr(Def) && getDLLAttr(Specialization) &&
7844 (Context.getTargetInfo().getCXXABI().isMicrosoft() ||
7845 Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment())) {
7846 // In the MS ABI, an explicit instantiation definition can add a dll
7847 // attribute to a template with a previous instantiation declaration.
7848 // MinGW doesn't allow this.
7849 auto *A = cast<InheritableAttr>(
7850 getDLLAttr(Specialization)->clone(getASTContext()));
7851 A->setInherited(true);
7853 dllExportImportClassTemplateSpecialization(*this, Def);
7857 // Fix a TSK_ImplicitInstantiation followed by a
7858 // TSK_ExplicitInstantiationDefinition
7859 bool NewlyDLLExported =
7860 !PreviouslyDLLExported && Specialization->hasAttr<DLLExportAttr>();
7861 if (Old_TSK == TSK_ImplicitInstantiation && NewlyDLLExported &&
7862 (Context.getTargetInfo().getCXXABI().isMicrosoft() ||
7863 Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment())) {
7864 // In the MS ABI, an explicit instantiation definition can add a dll
7865 // attribute to a template with a previous implicit instantiation.
7866 // MinGW doesn't allow this. We limit clang to only adding dllexport, to
7867 // avoid potentially strange codegen behavior. For example, if we extend
7868 // this conditional to dllimport, and we have a source file calling a
7869 // method on an implicitly instantiated template class instance and then
7870 // declaring a dllimport explicit instantiation definition for the same
7871 // template class, the codegen for the method call will not respect the
7872 // dllimport, while it will with cl. The Def will already have the DLL
7873 // attribute, since the Def and Specialization will be the same in the
7874 // case of Old_TSK == TSK_ImplicitInstantiation, and we already added the
7875 // attribute to the Specialization; we just need to make it take effect.
7876 assert(Def == Specialization &&
7877 "Def and Specialization should match for implicit instantiation");
7878 dllExportImportClassTemplateSpecialization(*this, Def);
7881 // Set the template specialization kind. Make sure it is set before
7882 // instantiating the members which will trigger ASTConsumer callbacks.
7883 Specialization->setTemplateSpecializationKind(TSK);
7884 InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK);
7887 // Set the template specialization kind.
7888 Specialization->setTemplateSpecializationKind(TSK);
7891 return Specialization;
7894 // Explicit instantiation of a member class of a class template.
7896 Sema::ActOnExplicitInstantiation(Scope *S,
7897 SourceLocation ExternLoc,
7898 SourceLocation TemplateLoc,
7900 SourceLocation KWLoc,
7902 IdentifierInfo *Name,
7903 SourceLocation NameLoc,
7904 AttributeList *Attr) {
7907 bool IsDependent = false;
7908 Decl *TagD = ActOnTag(S, TagSpec, Sema::TUK_Reference,
7909 KWLoc, SS, Name, NameLoc, Attr, AS_none,
7910 /*ModulePrivateLoc=*/SourceLocation(),
7911 MultiTemplateParamsArg(), Owned, IsDependent,
7912 SourceLocation(), false, TypeResult(),
7913 /*IsTypeSpecifier*/false);
7914 assert(!IsDependent && "explicit instantiation of dependent name not yet handled");
7919 TagDecl *Tag = cast<TagDecl>(TagD);
7920 assert(!Tag->isEnum() && "shouldn't see enumerations here");
7922 if (Tag->isInvalidDecl())
7925 CXXRecordDecl *Record = cast<CXXRecordDecl>(Tag);
7926 CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass();
7928 Diag(TemplateLoc, diag::err_explicit_instantiation_nontemplate_type)
7929 << Context.getTypeDeclType(Record);
7930 Diag(Record->getLocation(), diag::note_nontemplate_decl_here);
7934 // C++0x [temp.explicit]p2:
7935 // If the explicit instantiation is for a class or member class, the
7936 // elaborated-type-specifier in the declaration shall include a
7937 // simple-template-id.
7939 // C++98 has the same restriction, just worded differently.
7940 if (!ScopeSpecifierHasTemplateId(SS))
7941 Diag(TemplateLoc, diag::ext_explicit_instantiation_without_qualified_id)
7942 << Record << SS.getRange();
7944 // C++0x [temp.explicit]p2:
7945 // There are two forms of explicit instantiation: an explicit instantiation
7946 // definition and an explicit instantiation declaration. An explicit
7947 // instantiation declaration begins with the extern keyword. [...]
7948 TemplateSpecializationKind TSK
7949 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
7950 : TSK_ExplicitInstantiationDeclaration;
7952 // C++0x [temp.explicit]p2:
7953 // [...] An explicit instantiation shall appear in an enclosing
7954 // namespace of its template. [...]
7956 // This is C++ DR 275.
7957 CheckExplicitInstantiationScope(*this, Record, NameLoc, true);
7959 // Verify that it is okay to explicitly instantiate here.
7960 CXXRecordDecl *PrevDecl
7961 = cast_or_null<CXXRecordDecl>(Record->getPreviousDecl());
7962 if (!PrevDecl && Record->getDefinition())
7965 MemberSpecializationInfo *MSInfo = PrevDecl->getMemberSpecializationInfo();
7966 bool HasNoEffect = false;
7967 assert(MSInfo && "No member specialization information?");
7968 if (CheckSpecializationInstantiationRedecl(TemplateLoc, TSK,
7970 MSInfo->getTemplateSpecializationKind(),
7971 MSInfo->getPointOfInstantiation(),
7978 CXXRecordDecl *RecordDef
7979 = cast_or_null<CXXRecordDecl>(Record->getDefinition());
7981 // C++ [temp.explicit]p3:
7982 // A definition of a member class of a class template shall be in scope
7983 // at the point of an explicit instantiation of the member class.
7985 = cast_or_null<CXXRecordDecl>(Pattern->getDefinition());
7987 Diag(TemplateLoc, diag::err_explicit_instantiation_undefined_member)
7988 << 0 << Record->getDeclName() << Record->getDeclContext();
7989 Diag(Pattern->getLocation(), diag::note_forward_declaration)
7993 if (InstantiateClass(NameLoc, Record, Def,
7994 getTemplateInstantiationArgs(Record),
7998 RecordDef = cast_or_null<CXXRecordDecl>(Record->getDefinition());
8004 // Instantiate all of the members of the class.
8005 InstantiateClassMembers(NameLoc, RecordDef,
8006 getTemplateInstantiationArgs(Record), TSK);
8008 if (TSK == TSK_ExplicitInstantiationDefinition)
8009 MarkVTableUsed(NameLoc, RecordDef, true);
8011 // FIXME: We don't have any representation for explicit instantiations of
8012 // member classes. Such a representation is not needed for compilation, but it
8013 // should be available for clients that want to see all of the declarations in
8018 DeclResult Sema::ActOnExplicitInstantiation(Scope *S,
8019 SourceLocation ExternLoc,
8020 SourceLocation TemplateLoc,
8022 // Explicit instantiations always require a name.
8023 // TODO: check if/when DNInfo should replace Name.
8024 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
8025 DeclarationName Name = NameInfo.getName();
8027 if (!D.isInvalidType())
8028 Diag(D.getDeclSpec().getLocStart(),
8029 diag::err_explicit_instantiation_requires_name)
8030 << D.getDeclSpec().getSourceRange()
8031 << D.getSourceRange();
8036 // The scope passed in may not be a decl scope. Zip up the scope tree until
8037 // we find one that is.
8038 while ((S->getFlags() & Scope::DeclScope) == 0 ||
8039 (S->getFlags() & Scope::TemplateParamScope) != 0)
8042 // Determine the type of the declaration.
8043 TypeSourceInfo *T = GetTypeForDeclarator(D, S);
8044 QualType R = T->getType();
8049 // A storage-class-specifier shall not be specified in [...] an explicit
8050 // instantiation (14.7.2) directive.
8051 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
8052 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_of_typedef)
8055 } else if (D.getDeclSpec().getStorageClassSpec()
8056 != DeclSpec::SCS_unspecified) {
8057 // Complain about then remove the storage class specifier.
8058 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_storage_class)
8059 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
8061 D.getMutableDeclSpec().ClearStorageClassSpecs();
8064 // C++0x [temp.explicit]p1:
8065 // [...] An explicit instantiation of a function template shall not use the
8066 // inline or constexpr specifiers.
8067 // Presumably, this also applies to member functions of class templates as
8069 if (D.getDeclSpec().isInlineSpecified())
8070 Diag(D.getDeclSpec().getInlineSpecLoc(),
8071 getLangOpts().CPlusPlus11 ?
8072 diag::err_explicit_instantiation_inline :
8073 diag::warn_explicit_instantiation_inline_0x)
8074 << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
8075 if (D.getDeclSpec().isConstexprSpecified() && R->isFunctionType())
8076 // FIXME: Add a fix-it to remove the 'constexpr' and add a 'const' if one is
8077 // not already specified.
8078 Diag(D.getDeclSpec().getConstexprSpecLoc(),
8079 diag::err_explicit_instantiation_constexpr);
8081 // C++ Concepts TS [dcl.spec.concept]p1: The concept specifier shall be
8082 // applied only to the definition of a function template or variable template,
8083 // declared in namespace scope.
8084 if (D.getDeclSpec().isConceptSpecified()) {
8085 Diag(D.getDeclSpec().getConceptSpecLoc(),
8086 diag::err_concept_specified_specialization) << 0;
8090 // C++0x [temp.explicit]p2:
8091 // There are two forms of explicit instantiation: an explicit instantiation
8092 // definition and an explicit instantiation declaration. An explicit
8093 // instantiation declaration begins with the extern keyword. [...]
8094 TemplateSpecializationKind TSK
8095 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
8096 : TSK_ExplicitInstantiationDeclaration;
8098 LookupResult Previous(*this, NameInfo, LookupOrdinaryName);
8099 LookupParsedName(Previous, S, &D.getCXXScopeSpec());
8101 if (!R->isFunctionType()) {
8102 // C++ [temp.explicit]p1:
8103 // A [...] static data member of a class template can be explicitly
8104 // instantiated from the member definition associated with its class
8106 // C++1y [temp.explicit]p1:
8107 // A [...] variable [...] template specialization can be explicitly
8108 // instantiated from its template.
8109 if (Previous.isAmbiguous())
8112 VarDecl *Prev = Previous.getAsSingle<VarDecl>();
8113 VarTemplateDecl *PrevTemplate = Previous.getAsSingle<VarTemplateDecl>();
8115 if (!PrevTemplate) {
8116 if (!Prev || !Prev->isStaticDataMember()) {
8117 // We expect to see a data data member here.
8118 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_not_known)
8120 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
8122 Diag((*P)->getLocation(), diag::note_explicit_instantiation_here);
8126 if (!Prev->getInstantiatedFromStaticDataMember()) {
8127 // FIXME: Check for explicit specialization?
8128 Diag(D.getIdentifierLoc(),
8129 diag::err_explicit_instantiation_data_member_not_instantiated)
8131 Diag(Prev->getLocation(), diag::note_explicit_instantiation_here);
8132 // FIXME: Can we provide a note showing where this was declared?
8136 // Explicitly instantiate a variable template.
8138 // C++1y [dcl.spec.auto]p6:
8139 // ... A program that uses auto or decltype(auto) in a context not
8140 // explicitly allowed in this section is ill-formed.
8142 // This includes auto-typed variable template instantiations.
8143 if (R->isUndeducedType()) {
8144 Diag(T->getTypeLoc().getLocStart(),
8145 diag::err_auto_not_allowed_var_inst);
8149 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId) {
8150 // C++1y [temp.explicit]p3:
8151 // If the explicit instantiation is for a variable, the unqualified-id
8152 // in the declaration shall be a template-id.
8153 Diag(D.getIdentifierLoc(),
8154 diag::err_explicit_instantiation_without_template_id)
8156 Diag(PrevTemplate->getLocation(),
8157 diag::note_explicit_instantiation_here);
8161 // C++ Concepts TS [dcl.spec.concept]p7: A program shall not declare an
8162 // explicit instantiation (14.8.2) [...] of a concept definition.
8163 if (PrevTemplate->isConcept()) {
8164 Diag(D.getIdentifierLoc(), diag::err_concept_specialized)
8165 << 1 /*variable*/ << 0 /*explicitly instantiated*/;
8166 Diag(PrevTemplate->getLocation(), diag::note_previous_declaration);
8170 // Translate the parser's template argument list into our AST format.
8171 TemplateArgumentListInfo TemplateArgs =
8172 makeTemplateArgumentListInfo(*this, *D.getName().TemplateId);
8174 DeclResult Res = CheckVarTemplateId(PrevTemplate, TemplateLoc,
8175 D.getIdentifierLoc(), TemplateArgs);
8176 if (Res.isInvalid())
8179 // Ignore access control bits, we don't need them for redeclaration
8181 Prev = cast<VarDecl>(Res.get());
8184 // C++0x [temp.explicit]p2:
8185 // If the explicit instantiation is for a member function, a member class
8186 // or a static data member of a class template specialization, the name of
8187 // the class template specialization in the qualified-id for the member
8188 // name shall be a simple-template-id.
8190 // C++98 has the same restriction, just worded differently.
8192 // This does not apply to variable template specializations, where the
8193 // template-id is in the unqualified-id instead.
8194 if (!ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()) && !PrevTemplate)
8195 Diag(D.getIdentifierLoc(),
8196 diag::ext_explicit_instantiation_without_qualified_id)
8197 << Prev << D.getCXXScopeSpec().getRange();
8199 // Check the scope of this explicit instantiation.
8200 CheckExplicitInstantiationScope(*this, Prev, D.getIdentifierLoc(), true);
8202 // Verify that it is okay to explicitly instantiate here.
8203 TemplateSpecializationKind PrevTSK = Prev->getTemplateSpecializationKind();
8204 SourceLocation POI = Prev->getPointOfInstantiation();
8205 bool HasNoEffect = false;
8206 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, Prev,
8207 PrevTSK, POI, HasNoEffect))
8211 // Instantiate static data member or variable template.
8213 Prev->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
8215 // Merge attributes.
8216 if (AttributeList *Attr = D.getDeclSpec().getAttributes().getList())
8217 ProcessDeclAttributeList(S, Prev, Attr);
8219 if (TSK == TSK_ExplicitInstantiationDefinition)
8220 InstantiateVariableDefinition(D.getIdentifierLoc(), Prev);
8223 // Check the new variable specialization against the parsed input.
8224 if (PrevTemplate && Prev && !Context.hasSameType(Prev->getType(), R)) {
8225 Diag(T->getTypeLoc().getLocStart(),
8226 diag::err_invalid_var_template_spec_type)
8227 << 0 << PrevTemplate << R << Prev->getType();
8228 Diag(PrevTemplate->getLocation(), diag::note_template_declared_here)
8229 << 2 << PrevTemplate->getDeclName();
8233 // FIXME: Create an ExplicitInstantiation node?
8234 return (Decl*) nullptr;
8237 // If the declarator is a template-id, translate the parser's template
8238 // argument list into our AST format.
8239 bool HasExplicitTemplateArgs = false;
8240 TemplateArgumentListInfo TemplateArgs;
8241 if (D.getName().getKind() == UnqualifiedId::IK_TemplateId) {
8242 TemplateArgs = makeTemplateArgumentListInfo(*this, *D.getName().TemplateId);
8243 HasExplicitTemplateArgs = true;
8246 // C++ [temp.explicit]p1:
8247 // A [...] function [...] can be explicitly instantiated from its template.
8248 // A member function [...] of a class template can be explicitly
8249 // instantiated from the member definition associated with its class
8251 UnresolvedSet<8> Matches;
8252 AttributeList *Attr = D.getDeclSpec().getAttributes().getList();
8253 TemplateSpecCandidateSet FailedCandidates(D.getIdentifierLoc());
8254 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
8256 NamedDecl *Prev = *P;
8257 if (!HasExplicitTemplateArgs) {
8258 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Prev)) {
8259 QualType Adjusted = adjustCCAndNoReturn(R, Method->getType(),
8260 /*AdjustExceptionSpec*/true);
8261 if (Context.hasSameUnqualifiedType(Method->getType(), Adjusted)) {
8264 Matches.addDecl(Method, P.getAccess());
8265 if (Method->getTemplateSpecializationKind() == TSK_Undeclared)
8271 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Prev);
8275 TemplateDeductionInfo Info(FailedCandidates.getLocation());
8276 FunctionDecl *Specialization = nullptr;
8277 if (TemplateDeductionResult TDK
8278 = DeduceTemplateArguments(FunTmpl,
8279 (HasExplicitTemplateArgs ? &TemplateArgs
8281 R, Specialization, Info)) {
8282 // Keep track of almost-matches.
8283 FailedCandidates.addCandidate()
8284 .set(P.getPair(), FunTmpl->getTemplatedDecl(),
8285 MakeDeductionFailureInfo(Context, TDK, Info));
8290 // Target attributes are part of the cuda function signature, so
8291 // the cuda target of the instantiated function must match that of its
8292 // template. Given that C++ template deduction does not take
8293 // target attributes into account, we reject candidates here that
8294 // have a different target.
8295 if (LangOpts.CUDA &&
8296 IdentifyCUDATarget(Specialization,
8297 /* IgnoreImplicitHDAttributes = */ true) !=
8298 IdentifyCUDATarget(Attr)) {
8299 FailedCandidates.addCandidate().set(
8300 P.getPair(), FunTmpl->getTemplatedDecl(),
8301 MakeDeductionFailureInfo(Context, TDK_CUDATargetMismatch, Info));
8305 Matches.addDecl(Specialization, P.getAccess());
8308 // Find the most specialized function template specialization.
8309 UnresolvedSetIterator Result = getMostSpecialized(
8310 Matches.begin(), Matches.end(), FailedCandidates,
8311 D.getIdentifierLoc(),
8312 PDiag(diag::err_explicit_instantiation_not_known) << Name,
8313 PDiag(diag::err_explicit_instantiation_ambiguous) << Name,
8314 PDiag(diag::note_explicit_instantiation_candidate));
8316 if (Result == Matches.end())
8319 // Ignore access control bits, we don't need them for redeclaration checking.
8320 FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
8322 // C++11 [except.spec]p4
8323 // In an explicit instantiation an exception-specification may be specified,
8324 // but is not required.
8325 // If an exception-specification is specified in an explicit instantiation
8326 // directive, it shall be compatible with the exception-specifications of
8327 // other declarations of that function.
8328 if (auto *FPT = R->getAs<FunctionProtoType>())
8329 if (FPT->hasExceptionSpec()) {
8331 diag::err_mismatched_exception_spec_explicit_instantiation;
8332 if (getLangOpts().MicrosoftExt)
8333 DiagID = diag::ext_mismatched_exception_spec_explicit_instantiation;
8334 bool Result = CheckEquivalentExceptionSpec(
8335 PDiag(DiagID) << Specialization->getType(),
8336 PDiag(diag::note_explicit_instantiation_here),
8337 Specialization->getType()->getAs<FunctionProtoType>(),
8338 Specialization->getLocation(), FPT, D.getLocStart());
8339 // In Microsoft mode, mismatching exception specifications just cause a
8341 if (!getLangOpts().MicrosoftExt && Result)
8345 if (Specialization->getTemplateSpecializationKind() == TSK_Undeclared) {
8346 Diag(D.getIdentifierLoc(),
8347 diag::err_explicit_instantiation_member_function_not_instantiated)
8349 << (Specialization->getTemplateSpecializationKind() ==
8350 TSK_ExplicitSpecialization);
8351 Diag(Specialization->getLocation(), diag::note_explicit_instantiation_here);
8355 FunctionDecl *PrevDecl = Specialization->getPreviousDecl();
8356 if (!PrevDecl && Specialization->isThisDeclarationADefinition())
8357 PrevDecl = Specialization;
8360 bool HasNoEffect = false;
8361 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK,
8363 PrevDecl->getTemplateSpecializationKind(),
8364 PrevDecl->getPointOfInstantiation(),
8368 // FIXME: We may still want to build some representation of this
8369 // explicit specialization.
8371 return (Decl*) nullptr;
8374 Specialization->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
8376 ProcessDeclAttributeList(S, Specialization, Attr);
8378 if (Specialization->isDefined()) {
8379 // Let the ASTConsumer know that this function has been explicitly
8380 // instantiated now, and its linkage might have changed.
8381 Consumer.HandleTopLevelDecl(DeclGroupRef(Specialization));
8382 } else if (TSK == TSK_ExplicitInstantiationDefinition)
8383 InstantiateFunctionDefinition(D.getIdentifierLoc(), Specialization);
8385 // C++0x [temp.explicit]p2:
8386 // If the explicit instantiation is for a member function, a member class
8387 // or a static data member of a class template specialization, the name of
8388 // the class template specialization in the qualified-id for the member
8389 // name shall be a simple-template-id.
8391 // C++98 has the same restriction, just worded differently.
8392 FunctionTemplateDecl *FunTmpl = Specialization->getPrimaryTemplate();
8393 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId && !FunTmpl &&
8394 D.getCXXScopeSpec().isSet() &&
8395 !ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()))
8396 Diag(D.getIdentifierLoc(),
8397 diag::ext_explicit_instantiation_without_qualified_id)
8398 << Specialization << D.getCXXScopeSpec().getRange();
8400 // C++ Concepts TS [dcl.spec.concept]p7: A program shall not declare an
8401 // explicit instantiation (14.8.2) [...] of a concept definition.
8402 if (FunTmpl && FunTmpl->isConcept() &&
8403 !D.getDeclSpec().isConceptSpecified()) {
8404 Diag(D.getIdentifierLoc(), diag::err_concept_specialized)
8405 << 0 /*function*/ << 0 /*explicitly instantiated*/;
8406 Diag(FunTmpl->getLocation(), diag::note_previous_declaration);
8410 CheckExplicitInstantiationScope(*this,
8411 FunTmpl? (NamedDecl *)FunTmpl
8412 : Specialization->getInstantiatedFromMemberFunction(),
8413 D.getIdentifierLoc(),
8414 D.getCXXScopeSpec().isSet());
8416 // FIXME: Create some kind of ExplicitInstantiationDecl here.
8417 return (Decl*) nullptr;
8421 Sema::ActOnDependentTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
8422 const CXXScopeSpec &SS, IdentifierInfo *Name,
8423 SourceLocation TagLoc, SourceLocation NameLoc) {
8424 // This has to hold, because SS is expected to be defined.
8425 assert(Name && "Expected a name in a dependent tag");
8427 NestedNameSpecifier *NNS = SS.getScopeRep();
8431 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
8433 if (TUK == TUK_Declaration || TUK == TUK_Definition) {
8434 Diag(NameLoc, diag::err_dependent_tag_decl)
8435 << (TUK == TUK_Definition) << Kind << SS.getRange();
8439 // Create the resulting type.
8440 ElaboratedTypeKeyword Kwd = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
8441 QualType Result = Context.getDependentNameType(Kwd, NNS, Name);
8443 // Create type-source location information for this type.
8445 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(Result);
8446 TL.setElaboratedKeywordLoc(TagLoc);
8447 TL.setQualifierLoc(SS.getWithLocInContext(Context));
8448 TL.setNameLoc(NameLoc);
8449 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
8453 Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc,
8454 const CXXScopeSpec &SS, const IdentifierInfo &II,
8455 SourceLocation IdLoc) {
8459 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
8461 getLangOpts().CPlusPlus11 ?
8462 diag::warn_cxx98_compat_typename_outside_of_template :
8463 diag::ext_typename_outside_of_template)
8464 << FixItHint::CreateRemoval(TypenameLoc);
8466 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
8467 QualType T = CheckTypenameType(TypenameLoc.isValid()? ETK_Typename : ETK_None,
8468 TypenameLoc, QualifierLoc, II, IdLoc);
8472 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
8473 if (isa<DependentNameType>(T)) {
8474 DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
8475 TL.setElaboratedKeywordLoc(TypenameLoc);
8476 TL.setQualifierLoc(QualifierLoc);
8477 TL.setNameLoc(IdLoc);
8479 ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>();
8480 TL.setElaboratedKeywordLoc(TypenameLoc);
8481 TL.setQualifierLoc(QualifierLoc);
8482 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
8485 return CreateParsedType(T, TSI);
8489 Sema::ActOnTypenameType(Scope *S,
8490 SourceLocation TypenameLoc,
8491 const CXXScopeSpec &SS,
8492 SourceLocation TemplateKWLoc,
8493 TemplateTy TemplateIn,
8494 SourceLocation TemplateNameLoc,
8495 SourceLocation LAngleLoc,
8496 ASTTemplateArgsPtr TemplateArgsIn,
8497 SourceLocation RAngleLoc) {
8498 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
8500 getLangOpts().CPlusPlus11 ?
8501 diag::warn_cxx98_compat_typename_outside_of_template :
8502 diag::ext_typename_outside_of_template)
8503 << FixItHint::CreateRemoval(TypenameLoc);
8505 // Translate the parser's template argument list in our AST format.
8506 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
8507 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
8509 TemplateName Template = TemplateIn.get();
8510 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
8511 // Construct a dependent template specialization type.
8512 assert(DTN && "dependent template has non-dependent name?");
8513 assert(DTN->getQualifier() == SS.getScopeRep());
8514 QualType T = Context.getDependentTemplateSpecializationType(ETK_Typename,
8515 DTN->getQualifier(),
8516 DTN->getIdentifier(),
8519 // Create source-location information for this type.
8520 TypeLocBuilder Builder;
8521 DependentTemplateSpecializationTypeLoc SpecTL
8522 = Builder.push<DependentTemplateSpecializationTypeLoc>(T);
8523 SpecTL.setElaboratedKeywordLoc(TypenameLoc);
8524 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
8525 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
8526 SpecTL.setTemplateNameLoc(TemplateNameLoc);
8527 SpecTL.setLAngleLoc(LAngleLoc);
8528 SpecTL.setRAngleLoc(RAngleLoc);
8529 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
8530 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
8531 return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
8534 QualType T = CheckTemplateIdType(Template, TemplateNameLoc, TemplateArgs);
8538 // Provide source-location information for the template specialization type.
8539 TypeLocBuilder Builder;
8540 TemplateSpecializationTypeLoc SpecTL
8541 = Builder.push<TemplateSpecializationTypeLoc>(T);
8542 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
8543 SpecTL.setTemplateNameLoc(TemplateNameLoc);
8544 SpecTL.setLAngleLoc(LAngleLoc);
8545 SpecTL.setRAngleLoc(RAngleLoc);
8546 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
8547 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
8549 T = Context.getElaboratedType(ETK_Typename, SS.getScopeRep(), T);
8550 ElaboratedTypeLoc TL = Builder.push<ElaboratedTypeLoc>(T);
8551 TL.setElaboratedKeywordLoc(TypenameLoc);
8552 TL.setQualifierLoc(SS.getWithLocInContext(Context));
8554 TypeSourceInfo *TSI = Builder.getTypeSourceInfo(Context, T);
8555 return CreateParsedType(T, TSI);
8559 /// Determine whether this failed name lookup should be treated as being
8560 /// disabled by a usage of std::enable_if.
8561 static bool isEnableIf(NestedNameSpecifierLoc NNS, const IdentifierInfo &II,
8562 SourceRange &CondRange) {
8563 // We must be looking for a ::type...
8564 if (!II.isStr("type"))
8567 // ... within an explicitly-written template specialization...
8568 if (!NNS || !NNS.getNestedNameSpecifier()->getAsType())
8570 TypeLoc EnableIfTy = NNS.getTypeLoc();
8571 TemplateSpecializationTypeLoc EnableIfTSTLoc =
8572 EnableIfTy.getAs<TemplateSpecializationTypeLoc>();
8573 if (!EnableIfTSTLoc || EnableIfTSTLoc.getNumArgs() == 0)
8575 const TemplateSpecializationType *EnableIfTST =
8576 cast<TemplateSpecializationType>(EnableIfTSTLoc.getTypePtr());
8578 // ... which names a complete class template declaration...
8579 const TemplateDecl *EnableIfDecl =
8580 EnableIfTST->getTemplateName().getAsTemplateDecl();
8581 if (!EnableIfDecl || EnableIfTST->isIncompleteType())
8584 // ... called "enable_if".
8585 const IdentifierInfo *EnableIfII =
8586 EnableIfDecl->getDeclName().getAsIdentifierInfo();
8587 if (!EnableIfII || !EnableIfII->isStr("enable_if"))
8590 // Assume the first template argument is the condition.
8591 CondRange = EnableIfTSTLoc.getArgLoc(0).getSourceRange();
8595 /// \brief Build the type that describes a C++ typename specifier,
8596 /// e.g., "typename T::type".
8598 Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword,
8599 SourceLocation KeywordLoc,
8600 NestedNameSpecifierLoc QualifierLoc,
8601 const IdentifierInfo &II,
8602 SourceLocation IILoc) {
8604 SS.Adopt(QualifierLoc);
8606 DeclContext *Ctx = computeDeclContext(SS);
8608 // If the nested-name-specifier is dependent and couldn't be
8609 // resolved to a type, build a typename type.
8610 assert(QualifierLoc.getNestedNameSpecifier()->isDependent());
8611 return Context.getDependentNameType(Keyword,
8612 QualifierLoc.getNestedNameSpecifier(),
8616 // If the nested-name-specifier refers to the current instantiation,
8617 // the "typename" keyword itself is superfluous. In C++03, the
8618 // program is actually ill-formed. However, DR 382 (in C++0x CD1)
8619 // allows such extraneous "typename" keywords, and we retroactively
8620 // apply this DR to C++03 code with only a warning. In any case we continue.
8622 if (RequireCompleteDeclContext(SS, Ctx))
8625 DeclarationName Name(&II);
8626 LookupResult Result(*this, Name, IILoc, LookupOrdinaryName);
8627 LookupQualifiedName(Result, Ctx, SS);
8628 unsigned DiagID = 0;
8629 Decl *Referenced = nullptr;
8630 switch (Result.getResultKind()) {
8631 case LookupResult::NotFound: {
8632 // If we're looking up 'type' within a template named 'enable_if', produce
8633 // a more specific diagnostic.
8634 SourceRange CondRange;
8635 if (isEnableIf(QualifierLoc, II, CondRange)) {
8636 Diag(CondRange.getBegin(), diag::err_typename_nested_not_found_enable_if)
8637 << Ctx << CondRange;
8641 DiagID = diag::err_typename_nested_not_found;
8645 case LookupResult::FoundUnresolvedValue: {
8646 // We found a using declaration that is a value. Most likely, the using
8647 // declaration itself is meant to have the 'typename' keyword.
8648 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
8650 Diag(IILoc, diag::err_typename_refers_to_using_value_decl)
8651 << Name << Ctx << FullRange;
8652 if (UnresolvedUsingValueDecl *Using
8653 = dyn_cast<UnresolvedUsingValueDecl>(Result.getRepresentativeDecl())){
8654 SourceLocation Loc = Using->getQualifierLoc().getBeginLoc();
8655 Diag(Loc, diag::note_using_value_decl_missing_typename)
8656 << FixItHint::CreateInsertion(Loc, "typename ");
8659 // Fall through to create a dependent typename type, from which we can recover
8662 case LookupResult::NotFoundInCurrentInstantiation:
8663 // Okay, it's a member of an unknown instantiation.
8664 return Context.getDependentNameType(Keyword,
8665 QualifierLoc.getNestedNameSpecifier(),
8668 case LookupResult::Found:
8669 if (TypeDecl *Type = dyn_cast<TypeDecl>(Result.getFoundDecl())) {
8670 // We found a type. Build an ElaboratedType, since the
8671 // typename-specifier was just sugar.
8672 MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
8673 return Context.getElaboratedType(ETK_Typename,
8674 QualifierLoc.getNestedNameSpecifier(),
8675 Context.getTypeDeclType(Type));
8678 DiagID = diag::err_typename_nested_not_type;
8679 Referenced = Result.getFoundDecl();
8682 case LookupResult::FoundOverloaded:
8683 DiagID = diag::err_typename_nested_not_type;
8684 Referenced = *Result.begin();
8687 case LookupResult::Ambiguous:
8691 // If we get here, it's because name lookup did not find a
8692 // type. Emit an appropriate diagnostic and return an error.
8693 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
8695 Diag(IILoc, DiagID) << FullRange << Name << Ctx;
8697 Diag(Referenced->getLocation(), diag::note_typename_refers_here)
8703 // See Sema::RebuildTypeInCurrentInstantiation
8704 class CurrentInstantiationRebuilder
8705 : public TreeTransform<CurrentInstantiationRebuilder> {
8707 DeclarationName Entity;
8710 typedef TreeTransform<CurrentInstantiationRebuilder> inherited;
8712 CurrentInstantiationRebuilder(Sema &SemaRef,
8714 DeclarationName Entity)
8715 : TreeTransform<CurrentInstantiationRebuilder>(SemaRef),
8716 Loc(Loc), Entity(Entity) { }
8718 /// \brief Determine whether the given type \p T has already been
8721 /// For the purposes of type reconstruction, a type has already been
8722 /// transformed if it is NULL or if it is not dependent.
8723 bool AlreadyTransformed(QualType T) {
8724 return T.isNull() || !T->isDependentType();
8727 /// \brief Returns the location of the entity whose type is being
8729 SourceLocation getBaseLocation() { return Loc; }
8731 /// \brief Returns the name of the entity whose type is being rebuilt.
8732 DeclarationName getBaseEntity() { return Entity; }
8734 /// \brief Sets the "base" location and entity when that
8735 /// information is known based on another transformation.
8736 void setBase(SourceLocation Loc, DeclarationName Entity) {
8738 this->Entity = Entity;
8741 ExprResult TransformLambdaExpr(LambdaExpr *E) {
8742 // Lambdas never need to be transformed.
8746 } // end anonymous namespace
8748 /// \brief Rebuilds a type within the context of the current instantiation.
8750 /// The type \p T is part of the type of an out-of-line member definition of
8751 /// a class template (or class template partial specialization) that was parsed
8752 /// and constructed before we entered the scope of the class template (or
8753 /// partial specialization thereof). This routine will rebuild that type now
8754 /// that we have entered the declarator's scope, which may produce different
8755 /// canonical types, e.g.,
8758 /// template<typename T>
8760 /// typedef T* pointer;
8764 /// template<typename T>
8765 /// typename X<T>::pointer X<T>::data() { ... }
8768 /// Here, the type "typename X<T>::pointer" will be created as a DependentNameType,
8769 /// since we do not know that we can look into X<T> when we parsed the type.
8770 /// This function will rebuild the type, performing the lookup of "pointer"
8771 /// in X<T> and returning an ElaboratedType whose canonical type is the same
8772 /// as the canonical type of T*, allowing the return types of the out-of-line
8773 /// definition and the declaration to match.
8774 TypeSourceInfo *Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo *T,
8776 DeclarationName Name) {
8777 if (!T || !T->getType()->isDependentType())
8780 CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name);
8781 return Rebuilder.TransformType(T);
8784 ExprResult Sema::RebuildExprInCurrentInstantiation(Expr *E) {
8785 CurrentInstantiationRebuilder Rebuilder(*this, E->getExprLoc(),
8787 return Rebuilder.TransformExpr(E);
8790 bool Sema::RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS) {
8794 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
8795 CurrentInstantiationRebuilder Rebuilder(*this, SS.getRange().getBegin(),
8797 NestedNameSpecifierLoc Rebuilt
8798 = Rebuilder.TransformNestedNameSpecifierLoc(QualifierLoc);
8806 /// \brief Rebuild the template parameters now that we know we're in a current
8808 bool Sema::RebuildTemplateParamsInCurrentInstantiation(
8809 TemplateParameterList *Params) {
8810 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
8811 Decl *Param = Params->getParam(I);
8813 // There is nothing to rebuild in a type parameter.
8814 if (isa<TemplateTypeParmDecl>(Param))
8817 // Rebuild the template parameter list of a template template parameter.
8818 if (TemplateTemplateParmDecl *TTP
8819 = dyn_cast<TemplateTemplateParmDecl>(Param)) {
8820 if (RebuildTemplateParamsInCurrentInstantiation(
8821 TTP->getTemplateParameters()))
8827 // Rebuild the type of a non-type template parameter.
8828 NonTypeTemplateParmDecl *NTTP = cast<NonTypeTemplateParmDecl>(Param);
8829 TypeSourceInfo *NewTSI
8830 = RebuildTypeInCurrentInstantiation(NTTP->getTypeSourceInfo(),
8831 NTTP->getLocation(),
8832 NTTP->getDeclName());
8836 if (NewTSI != NTTP->getTypeSourceInfo()) {
8837 NTTP->setTypeSourceInfo(NewTSI);
8838 NTTP->setType(NewTSI->getType());
8845 /// \brief Produces a formatted string that describes the binding of
8846 /// template parameters to template arguments.
8848 Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
8849 const TemplateArgumentList &Args) {
8850 return getTemplateArgumentBindingsText(Params, Args.data(), Args.size());
8854 Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
8855 const TemplateArgument *Args,
8857 SmallString<128> Str;
8858 llvm::raw_svector_ostream Out(Str);
8860 if (!Params || Params->size() == 0 || NumArgs == 0)
8861 return std::string();
8863 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
8872 if (const IdentifierInfo *Id = Params->getParam(I)->getIdentifier()) {
8873 Out << Id->getName();
8879 Args[I].print(getPrintingPolicy(), Out);
8886 void Sema::MarkAsLateParsedTemplate(FunctionDecl *FD, Decl *FnD,
8887 CachedTokens &Toks) {
8891 auto LPT = llvm::make_unique<LateParsedTemplate>();
8893 // Take tokens to avoid allocations
8894 LPT->Toks.swap(Toks);
8896 LateParsedTemplateMap.insert(std::make_pair(FD, std::move(LPT)));
8898 FD->setLateTemplateParsed(true);
8901 void Sema::UnmarkAsLateParsedTemplate(FunctionDecl *FD) {
8904 FD->setLateTemplateParsed(false);
8907 bool Sema::IsInsideALocalClassWithinATemplateFunction() {
8908 DeclContext *DC = CurContext;
8911 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(CurContext)) {
8912 const FunctionDecl *FD = RD->isLocalClass();
8913 return (FD && FD->getTemplatedKind() != FunctionDecl::TK_NonTemplate);
8914 } else if (DC->isTranslationUnit() || DC->isNamespace())
8917 DC = DC->getParent();
8923 /// \brief Walk the path from which a declaration was instantiated, and check
8924 /// that every explicit specialization along that path is visible. This enforces
8925 /// C++ [temp.expl.spec]/6:
8927 /// If a template, a member template or a member of a class template is
8928 /// explicitly specialized then that specialization shall be declared before
8929 /// the first use of that specialization that would cause an implicit
8930 /// instantiation to take place, in every translation unit in which such a
8931 /// use occurs; no diagnostic is required.
8933 /// and also C++ [temp.class.spec]/1:
8935 /// A partial specialization shall be declared before the first use of a
8936 /// class template specialization that would make use of the partial
8937 /// specialization as the result of an implicit or explicit instantiation
8938 /// in every translation unit in which such a use occurs; no diagnostic is
8940 class ExplicitSpecializationVisibilityChecker {
8943 llvm::SmallVector<Module *, 8> Modules;
8946 ExplicitSpecializationVisibilityChecker(Sema &S, SourceLocation Loc)
8949 void check(NamedDecl *ND) {
8950 if (auto *FD = dyn_cast<FunctionDecl>(ND))
8951 return checkImpl(FD);
8952 if (auto *RD = dyn_cast<CXXRecordDecl>(ND))
8953 return checkImpl(RD);
8954 if (auto *VD = dyn_cast<VarDecl>(ND))
8955 return checkImpl(VD);
8956 if (auto *ED = dyn_cast<EnumDecl>(ND))
8957 return checkImpl(ED);
8961 void diagnose(NamedDecl *D, bool IsPartialSpec) {
8962 auto Kind = IsPartialSpec ? Sema::MissingImportKind::PartialSpecialization
8963 : Sema::MissingImportKind::ExplicitSpecialization;
8964 const bool Recover = true;
8966 // If we got a custom set of modules (because only a subset of the
8967 // declarations are interesting), use them, otherwise let
8968 // diagnoseMissingImport intelligently pick some.
8969 if (Modules.empty())
8970 S.diagnoseMissingImport(Loc, D, Kind, Recover);
8972 S.diagnoseMissingImport(Loc, D, D->getLocation(), Modules, Kind, Recover);
8975 // Check a specific declaration. There are three problematic cases:
8977 // 1) The declaration is an explicit specialization of a template
8979 // 2) The declaration is an explicit specialization of a member of an
8981 // 3) The declaration is an instantiation of a template, and that template
8982 // is an explicit specialization of a member of a templated class.
8984 // We don't need to go any deeper than that, as the instantiation of the
8985 // surrounding class / etc is not triggered by whatever triggered this
8986 // instantiation, and thus should be checked elsewhere.
8987 template<typename SpecDecl>
8988 void checkImpl(SpecDecl *Spec) {
8989 bool IsHiddenExplicitSpecialization = false;
8990 if (Spec->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) {
8991 IsHiddenExplicitSpecialization =
8992 Spec->getMemberSpecializationInfo()
8993 ? !S.hasVisibleMemberSpecialization(Spec, &Modules)
8994 : !S.hasVisibleDeclaration(Spec);
8996 checkInstantiated(Spec);
8999 if (IsHiddenExplicitSpecialization)
9000 diagnose(Spec->getMostRecentDecl(), false);
9003 void checkInstantiated(FunctionDecl *FD) {
9004 if (auto *TD = FD->getPrimaryTemplate())
9008 void checkInstantiated(CXXRecordDecl *RD) {
9009 auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(RD);
9013 auto From = SD->getSpecializedTemplateOrPartial();
9014 if (auto *TD = From.dyn_cast<ClassTemplateDecl *>())
9017 From.dyn_cast<ClassTemplatePartialSpecializationDecl *>()) {
9018 if (!S.hasVisibleDeclaration(TD))
9024 void checkInstantiated(VarDecl *RD) {
9025 auto *SD = dyn_cast<VarTemplateSpecializationDecl>(RD);
9029 auto From = SD->getSpecializedTemplateOrPartial();
9030 if (auto *TD = From.dyn_cast<VarTemplateDecl *>())
9033 From.dyn_cast<VarTemplatePartialSpecializationDecl *>()) {
9034 if (!S.hasVisibleDeclaration(TD))
9040 void checkInstantiated(EnumDecl *FD) {}
9042 template<typename TemplDecl>
9043 void checkTemplate(TemplDecl *TD) {
9044 if (TD->isMemberSpecialization()) {
9045 if (!S.hasVisibleMemberSpecialization(TD, &Modules))
9046 diagnose(TD->getMostRecentDecl(), false);
9050 } // end anonymous namespace
9052 void Sema::checkSpecializationVisibility(SourceLocation Loc, NamedDecl *Spec) {
9053 if (!getLangOpts().Modules)
9056 ExplicitSpecializationVisibilityChecker(*this, Loc).check(Spec);
9059 /// \brief Check whether a template partial specialization that we've discovered
9060 /// is hidden, and produce suitable diagnostics if so.
9061 void Sema::checkPartialSpecializationVisibility(SourceLocation Loc,
9063 llvm::SmallVector<Module *, 8> Modules;
9064 if (!hasVisibleDeclaration(Spec, &Modules))
9065 diagnoseMissingImport(Loc, Spec, Spec->getLocation(), Modules,
9066 MissingImportKind::PartialSpecialization,