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 // C++ [temp.deduct.type]p17: (DR1770)
5131 // If P has a form that contains <i>, and if the type of i differs from
5132 // the type of the corresponding template parameter of the template named
5133 // by the enclosing simple-template-id, deduction fails.
5135 // Note that CTAK will be CTAK_DeducedFromArrayBound if the form was [i]
5138 // FIXME: We interpret the 'i' here as referring to the expression
5139 // denoting the non-type template parameter rather than the parameter
5140 // itself, and so strip off references before comparing types. It's
5141 // not clear how this is supposed to work for references.
5142 Diag(StartLoc, diag::err_deduced_non_type_template_arg_type_mismatch)
5144 << ParamType.getUnqualifiedType();
5145 Diag(Param->getLocation(), diag::note_template_param_here);
5149 // If either the parameter has a dependent type or the argument is
5150 // type-dependent, there's nothing we can check now.
5151 if (ParamType->isDependentType() || Arg->isTypeDependent()) {
5152 // FIXME: Produce a cloned, canonical expression?
5153 Converted = TemplateArgument(Arg);
5157 // The initialization of the parameter from the argument is
5158 // a constant-evaluated context.
5159 EnterExpressionEvaluationContext ConstantEvaluated(*this,
5160 Sema::ConstantEvaluated);
5162 if (getLangOpts().CPlusPlus1z) {
5163 // C++1z [temp.arg.nontype]p1:
5164 // A template-argument for a non-type template parameter shall be
5165 // a converted constant expression of the type of the template-parameter.
5167 ExprResult ArgResult = CheckConvertedConstantExpression(
5168 Arg, ParamType, Value, CCEK_TemplateArg);
5169 if (ArgResult.isInvalid())
5172 // For a value-dependent argument, CheckConvertedConstantExpression is
5173 // permitted (and expected) to be unable to determine a value.
5174 if (ArgResult.get()->isValueDependent()) {
5175 Converted = TemplateArgument(ArgResult.get());
5179 QualType CanonParamType = Context.getCanonicalType(ParamType);
5181 // Convert the APValue to a TemplateArgument.
5182 switch (Value.getKind()) {
5183 case APValue::Uninitialized:
5184 assert(ParamType->isNullPtrType());
5185 Converted = TemplateArgument(CanonParamType, /*isNullPtr*/true);
5188 assert(ParamType->isIntegralOrEnumerationType());
5189 Converted = TemplateArgument(Context, Value.getInt(), CanonParamType);
5191 case APValue::MemberPointer: {
5192 assert(ParamType->isMemberPointerType());
5194 // FIXME: We need TemplateArgument representation and mangling for these.
5195 if (!Value.getMemberPointerPath().empty()) {
5196 Diag(Arg->getLocStart(),
5197 diag::err_template_arg_member_ptr_base_derived_not_supported)
5198 << Value.getMemberPointerDecl() << ParamType
5199 << Arg->getSourceRange();
5203 auto *VD = const_cast<ValueDecl*>(Value.getMemberPointerDecl());
5204 Converted = VD ? TemplateArgument(VD, CanonParamType)
5205 : TemplateArgument(CanonParamType, /*isNullPtr*/true);
5208 case APValue::LValue: {
5209 // For a non-type template-parameter of pointer or reference type,
5210 // the value of the constant expression shall not refer to
5211 assert(ParamType->isPointerType() || ParamType->isReferenceType() ||
5212 ParamType->isNullPtrType());
5213 // -- a temporary object
5214 // -- a string literal
5215 // -- the result of a typeid expression, or
5216 // -- a predefind __func__ variable
5217 if (auto *E = Value.getLValueBase().dyn_cast<const Expr*>()) {
5218 if (isa<CXXUuidofExpr>(E)) {
5219 Converted = TemplateArgument(const_cast<Expr*>(E));
5222 Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
5223 << Arg->getSourceRange();
5226 auto *VD = const_cast<ValueDecl *>(
5227 Value.getLValueBase().dyn_cast<const ValueDecl *>());
5229 if (Value.hasLValuePath() && Value.getLValuePath().size() == 1 &&
5230 VD && VD->getType()->isArrayType() &&
5231 Value.getLValuePath()[0].ArrayIndex == 0 &&
5232 !Value.isLValueOnePastTheEnd() && ParamType->isPointerType()) {
5233 // Per defect report (no number yet):
5234 // ... other than a pointer to the first element of a complete array
5236 } else if (!Value.hasLValuePath() || Value.getLValuePath().size() ||
5237 Value.isLValueOnePastTheEnd()) {
5238 Diag(StartLoc, diag::err_non_type_template_arg_subobject)
5239 << Value.getAsString(Context, ParamType);
5242 assert((VD || !ParamType->isReferenceType()) &&
5243 "null reference should not be a constant expression");
5244 assert((!VD || !ParamType->isNullPtrType()) &&
5245 "non-null value of type nullptr_t?");
5246 Converted = VD ? TemplateArgument(VD, CanonParamType)
5247 : TemplateArgument(CanonParamType, /*isNullPtr*/true);
5250 case APValue::AddrLabelDiff:
5251 return Diag(StartLoc, diag::err_non_type_template_arg_addr_label_diff);
5252 case APValue::Float:
5253 case APValue::ComplexInt:
5254 case APValue::ComplexFloat:
5255 case APValue::Vector:
5256 case APValue::Array:
5257 case APValue::Struct:
5258 case APValue::Union:
5259 llvm_unreachable("invalid kind for template argument");
5262 return ArgResult.get();
5265 // C++ [temp.arg.nontype]p5:
5266 // The following conversions are performed on each expression used
5267 // as a non-type template-argument. If a non-type
5268 // template-argument cannot be converted to the type of the
5269 // corresponding template-parameter then the program is
5271 if (ParamType->isIntegralOrEnumerationType()) {
5273 // -- for a non-type template-parameter of integral or
5274 // enumeration type, conversions permitted in a converted
5275 // constant expression are applied.
5278 // -- for a non-type template-parameter of integral or
5279 // enumeration type, integral promotions (4.5) and integral
5280 // conversions (4.7) are applied.
5282 if (getLangOpts().CPlusPlus11) {
5283 // C++ [temp.arg.nontype]p1:
5284 // A template-argument for a non-type, non-template template-parameter
5287 // -- for a non-type template-parameter of integral or enumeration
5288 // type, a converted constant expression of the type of the
5289 // template-parameter; or
5291 ExprResult ArgResult =
5292 CheckConvertedConstantExpression(Arg, ParamType, Value,
5294 if (ArgResult.isInvalid())
5297 // We can't check arbitrary value-dependent arguments.
5298 if (ArgResult.get()->isValueDependent()) {
5299 Converted = TemplateArgument(ArgResult.get());
5303 // Widen the argument value to sizeof(parameter type). This is almost
5304 // always a no-op, except when the parameter type is bool. In
5305 // that case, this may extend the argument from 1 bit to 8 bits.
5306 QualType IntegerType = ParamType;
5307 if (const EnumType *Enum = IntegerType->getAs<EnumType>())
5308 IntegerType = Enum->getDecl()->getIntegerType();
5309 Value = Value.extOrTrunc(Context.getTypeSize(IntegerType));
5311 Converted = TemplateArgument(Context, Value,
5312 Context.getCanonicalType(ParamType));
5316 ExprResult ArgResult = DefaultLvalueConversion(Arg);
5317 if (ArgResult.isInvalid())
5319 Arg = ArgResult.get();
5321 QualType ArgType = Arg->getType();
5323 // C++ [temp.arg.nontype]p1:
5324 // A template-argument for a non-type, non-template
5325 // template-parameter shall be one of:
5327 // -- an integral constant-expression of integral or enumeration
5329 // -- the name of a non-type template-parameter; or
5330 SourceLocation NonConstantLoc;
5332 if (!ArgType->isIntegralOrEnumerationType()) {
5333 Diag(Arg->getLocStart(),
5334 diag::err_template_arg_not_integral_or_enumeral)
5335 << ArgType << Arg->getSourceRange();
5336 Diag(Param->getLocation(), diag::note_template_param_here);
5338 } else if (!Arg->isValueDependent()) {
5339 class TmplArgICEDiagnoser : public VerifyICEDiagnoser {
5343 TmplArgICEDiagnoser(QualType T) : T(T) { }
5345 void diagnoseNotICE(Sema &S, SourceLocation Loc,
5346 SourceRange SR) override {
5347 S.Diag(Loc, diag::err_template_arg_not_ice) << T << SR;
5349 } Diagnoser(ArgType);
5351 Arg = VerifyIntegerConstantExpression(Arg, &Value, Diagnoser,
5357 // From here on out, all we care about is the unqualified form
5358 // of the argument type.
5359 ArgType = ArgType.getUnqualifiedType();
5361 // Try to convert the argument to the parameter's type.
5362 if (Context.hasSameType(ParamType, ArgType)) {
5363 // Okay: no conversion necessary
5364 } else if (ParamType->isBooleanType()) {
5365 // This is an integral-to-boolean conversion.
5366 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralToBoolean).get();
5367 } else if (IsIntegralPromotion(Arg, ArgType, ParamType) ||
5368 !ParamType->isEnumeralType()) {
5369 // This is an integral promotion or conversion.
5370 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralCast).get();
5372 // We can't perform this conversion.
5373 Diag(Arg->getLocStart(),
5374 diag::err_template_arg_not_convertible)
5375 << Arg->getType() << ParamType << Arg->getSourceRange();
5376 Diag(Param->getLocation(), diag::note_template_param_here);
5380 // Add the value of this argument to the list of converted
5381 // arguments. We use the bitwidth and signedness of the template
5383 if (Arg->isValueDependent()) {
5384 // The argument is value-dependent. Create a new
5385 // TemplateArgument with the converted expression.
5386 Converted = TemplateArgument(Arg);
5390 QualType IntegerType = Context.getCanonicalType(ParamType);
5391 if (const EnumType *Enum = IntegerType->getAs<EnumType>())
5392 IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType());
5394 if (ParamType->isBooleanType()) {
5395 // Value must be zero or one.
5397 unsigned AllowedBits = Context.getTypeSize(IntegerType);
5398 if (Value.getBitWidth() != AllowedBits)
5399 Value = Value.extOrTrunc(AllowedBits);
5400 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
5402 llvm::APSInt OldValue = Value;
5404 // Coerce the template argument's value to the value it will have
5405 // based on the template parameter's type.
5406 unsigned AllowedBits = Context.getTypeSize(IntegerType);
5407 if (Value.getBitWidth() != AllowedBits)
5408 Value = Value.extOrTrunc(AllowedBits);
5409 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
5411 // Complain if an unsigned parameter received a negative value.
5412 if (IntegerType->isUnsignedIntegerOrEnumerationType()
5413 && (OldValue.isSigned() && OldValue.isNegative())) {
5414 Diag(Arg->getLocStart(), diag::warn_template_arg_negative)
5415 << OldValue.toString(10) << Value.toString(10) << Param->getType()
5416 << Arg->getSourceRange();
5417 Diag(Param->getLocation(), diag::note_template_param_here);
5420 // Complain if we overflowed the template parameter's type.
5421 unsigned RequiredBits;
5422 if (IntegerType->isUnsignedIntegerOrEnumerationType())
5423 RequiredBits = OldValue.getActiveBits();
5424 else if (OldValue.isUnsigned())
5425 RequiredBits = OldValue.getActiveBits() + 1;
5427 RequiredBits = OldValue.getMinSignedBits();
5428 if (RequiredBits > AllowedBits) {
5429 Diag(Arg->getLocStart(),
5430 diag::warn_template_arg_too_large)
5431 << OldValue.toString(10) << Value.toString(10) << Param->getType()
5432 << Arg->getSourceRange();
5433 Diag(Param->getLocation(), diag::note_template_param_here);
5437 Converted = TemplateArgument(Context, Value,
5438 ParamType->isEnumeralType()
5439 ? Context.getCanonicalType(ParamType)
5444 QualType ArgType = Arg->getType();
5445 DeclAccessPair FoundResult; // temporary for ResolveOverloadedFunction
5447 // Handle pointer-to-function, reference-to-function, and
5448 // pointer-to-member-function all in (roughly) the same way.
5449 if (// -- For a non-type template-parameter of type pointer to
5450 // function, only the function-to-pointer conversion (4.3) is
5451 // applied. If the template-argument represents a set of
5452 // overloaded functions (or a pointer to such), the matching
5453 // function is selected from the set (13.4).
5454 (ParamType->isPointerType() &&
5455 ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType()) ||
5456 // -- For a non-type template-parameter of type reference to
5457 // function, no conversions apply. If the template-argument
5458 // represents a set of overloaded functions, the matching
5459 // function is selected from the set (13.4).
5460 (ParamType->isReferenceType() &&
5461 ParamType->getAs<ReferenceType>()->getPointeeType()->isFunctionType()) ||
5462 // -- For a non-type template-parameter of type pointer to
5463 // member function, no conversions apply. If the
5464 // template-argument represents a set of overloaded member
5465 // functions, the matching member function is selected from
5467 (ParamType->isMemberPointerType() &&
5468 ParamType->getAs<MemberPointerType>()->getPointeeType()
5469 ->isFunctionType())) {
5471 if (Arg->getType() == Context.OverloadTy) {
5472 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType,
5475 if (DiagnoseUseOfDecl(Fn, Arg->getLocStart()))
5478 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
5479 ArgType = Arg->getType();
5484 if (!ParamType->isMemberPointerType()) {
5485 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5492 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
5498 if (ParamType->isPointerType()) {
5499 // -- for a non-type template-parameter of type pointer to
5500 // object, qualification conversions (4.4) and the
5501 // array-to-pointer conversion (4.2) are applied.
5502 // C++0x also allows a value of std::nullptr_t.
5503 assert(ParamType->getPointeeType()->isIncompleteOrObjectType() &&
5504 "Only object pointers allowed here");
5506 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5513 if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) {
5514 // -- For a non-type template-parameter of type reference to
5515 // object, no conversions apply. The type referred to by the
5516 // reference may be more cv-qualified than the (otherwise
5517 // identical) type of the template-argument. The
5518 // template-parameter is bound directly to the
5519 // template-argument, which must be an lvalue.
5520 assert(ParamRefType->getPointeeType()->isIncompleteOrObjectType() &&
5521 "Only object references allowed here");
5523 if (Arg->getType() == Context.OverloadTy) {
5524 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg,
5525 ParamRefType->getPointeeType(),
5528 if (DiagnoseUseOfDecl(Fn, Arg->getLocStart()))
5531 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
5532 ArgType = Arg->getType();
5537 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5544 // Deal with parameters of type std::nullptr_t.
5545 if (ParamType->isNullPtrType()) {
5546 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
5547 Converted = TemplateArgument(Arg);
5551 switch (isNullPointerValueTemplateArgument(*this, Param, ParamType, Arg)) {
5552 case NPV_NotNullPointer:
5553 Diag(Arg->getExprLoc(), diag::err_template_arg_not_convertible)
5554 << Arg->getType() << ParamType;
5555 Diag(Param->getLocation(), diag::note_template_param_here);
5561 case NPV_NullPointer:
5562 Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
5563 Converted = TemplateArgument(Context.getCanonicalType(ParamType),
5569 // -- For a non-type template-parameter of type pointer to data
5570 // member, qualification conversions (4.4) are applied.
5571 assert(ParamType->isMemberPointerType() && "Only pointers to members remain");
5573 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
5579 static void DiagnoseTemplateParameterListArityMismatch(
5580 Sema &S, TemplateParameterList *New, TemplateParameterList *Old,
5581 Sema::TemplateParameterListEqualKind Kind, SourceLocation TemplateArgLoc);
5583 /// \brief Check a template argument against its corresponding
5584 /// template template parameter.
5586 /// This routine implements the semantics of C++ [temp.arg.template].
5587 /// It returns true if an error occurred, and false otherwise.
5588 bool Sema::CheckTemplateArgument(TemplateTemplateParmDecl *Param,
5589 TemplateArgumentLoc &Arg,
5590 unsigned ArgumentPackIndex) {
5591 TemplateName Name = Arg.getArgument().getAsTemplateOrTemplatePattern();
5592 TemplateDecl *Template = Name.getAsTemplateDecl();
5594 // Any dependent template name is fine.
5595 assert(Name.isDependent() && "Non-dependent template isn't a declaration?");
5599 if (Template->isInvalidDecl())
5602 // C++0x [temp.arg.template]p1:
5603 // A template-argument for a template template-parameter shall be
5604 // the name of a class template or an alias template, expressed as an
5605 // id-expression. When the template-argument names a class template, only
5606 // primary class templates are considered when matching the
5607 // template template argument with the corresponding parameter;
5608 // partial specializations are not considered even if their
5609 // parameter lists match that of the template template parameter.
5611 // Note that we also allow template template parameters here, which
5612 // will happen when we are dealing with, e.g., class template
5613 // partial specializations.
5614 if (!isa<ClassTemplateDecl>(Template) &&
5615 !isa<TemplateTemplateParmDecl>(Template) &&
5616 !isa<TypeAliasTemplateDecl>(Template) &&
5617 !isa<BuiltinTemplateDecl>(Template)) {
5618 assert(isa<FunctionTemplateDecl>(Template) &&
5619 "Only function templates are possible here");
5620 Diag(Arg.getLocation(), diag::err_template_arg_not_valid_template);
5621 Diag(Template->getLocation(), diag::note_template_arg_refers_here_func)
5625 TemplateParameterList *Params = Param->getTemplateParameters();
5626 if (Param->isExpandedParameterPack())
5627 Params = Param->getExpansionTemplateParameters(ArgumentPackIndex);
5629 // C++1z [temp.arg.template]p3: (DR 150)
5630 // A template-argument matches a template template-parameter P when P
5631 // is at least as specialized as the template-argument A.
5632 if (getLangOpts().RelaxedTemplateTemplateArgs) {
5633 // Quick check for the common case:
5634 // If P contains a parameter pack, then A [...] matches P if each of A's
5635 // template parameters matches the corresponding template parameter in
5636 // the template-parameter-list of P.
5637 if (TemplateParameterListsAreEqual(
5638 Template->getTemplateParameters(), Params, false,
5639 TPL_TemplateTemplateArgumentMatch, Arg.getLocation()))
5642 if (isTemplateTemplateParameterAtLeastAsSpecializedAs(Params, Template,
5645 // FIXME: Produce better diagnostics for deduction failures.
5648 return !TemplateParameterListsAreEqual(Template->getTemplateParameters(),
5651 TPL_TemplateTemplateArgumentMatch,
5655 /// \brief Given a non-type template argument that refers to a
5656 /// declaration and the type of its corresponding non-type template
5657 /// parameter, produce an expression that properly refers to that
5660 Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
5662 SourceLocation Loc) {
5663 // C++ [temp.param]p8:
5665 // A non-type template-parameter of type "array of T" or
5666 // "function returning T" is adjusted to be of type "pointer to
5667 // T" or "pointer to function returning T", respectively.
5668 if (ParamType->isArrayType())
5669 ParamType = Context.getArrayDecayedType(ParamType);
5670 else if (ParamType->isFunctionType())
5671 ParamType = Context.getPointerType(ParamType);
5673 // For a NULL non-type template argument, return nullptr casted to the
5674 // parameter's type.
5675 if (Arg.getKind() == TemplateArgument::NullPtr) {
5676 return ImpCastExprToType(
5677 new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc),
5679 ParamType->getAs<MemberPointerType>()
5680 ? CK_NullToMemberPointer
5681 : CK_NullToPointer);
5683 assert(Arg.getKind() == TemplateArgument::Declaration &&
5684 "Only declaration template arguments permitted here");
5686 ValueDecl *VD = cast<ValueDecl>(Arg.getAsDecl());
5688 if (VD->getDeclContext()->isRecord() &&
5689 (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD) ||
5690 isa<IndirectFieldDecl>(VD))) {
5691 // If the value is a class member, we might have a pointer-to-member.
5692 // Determine whether the non-type template template parameter is of
5693 // pointer-to-member type. If so, we need to build an appropriate
5694 // expression for a pointer-to-member, since a "normal" DeclRefExpr
5695 // would refer to the member itself.
5696 if (ParamType->isMemberPointerType()) {
5698 = Context.getTypeDeclType(cast<RecordDecl>(VD->getDeclContext()));
5699 NestedNameSpecifier *Qualifier
5700 = NestedNameSpecifier::Create(Context, nullptr, false,
5701 ClassType.getTypePtr());
5703 SS.MakeTrivial(Context, Qualifier, Loc);
5705 // The actual value-ness of this is unimportant, but for
5706 // internal consistency's sake, references to instance methods
5708 ExprValueKind VK = VK_LValue;
5709 if (isa<CXXMethodDecl>(VD) && cast<CXXMethodDecl>(VD)->isInstance())
5712 ExprResult RefExpr = BuildDeclRefExpr(VD,
5713 VD->getType().getNonReferenceType(),
5717 if (RefExpr.isInvalid())
5720 RefExpr = CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
5722 // We might need to perform a trailing qualification conversion, since
5723 // the element type on the parameter could be more qualified than the
5724 // element type in the expression we constructed.
5725 bool ObjCLifetimeConversion;
5726 if (IsQualificationConversion(((Expr*) RefExpr.get())->getType(),
5727 ParamType.getUnqualifiedType(), false,
5728 ObjCLifetimeConversion))
5729 RefExpr = ImpCastExprToType(RefExpr.get(), ParamType.getUnqualifiedType(), CK_NoOp);
5731 assert(!RefExpr.isInvalid() &&
5732 Context.hasSameType(((Expr*) RefExpr.get())->getType(),
5733 ParamType.getUnqualifiedType()));
5738 QualType T = VD->getType().getNonReferenceType();
5740 if (ParamType->isPointerType()) {
5741 // When the non-type template parameter is a pointer, take the
5742 // address of the declaration.
5743 ExprResult RefExpr = BuildDeclRefExpr(VD, T, VK_LValue, Loc);
5744 if (RefExpr.isInvalid())
5747 if (T->isFunctionType() || T->isArrayType()) {
5748 // Decay functions and arrays.
5749 RefExpr = DefaultFunctionArrayConversion(RefExpr.get());
5750 if (RefExpr.isInvalid())
5756 // Take the address of everything else
5757 return CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
5760 ExprValueKind VK = VK_RValue;
5762 // If the non-type template parameter has reference type, qualify the
5763 // resulting declaration reference with the extra qualifiers on the
5764 // type that the reference refers to.
5765 if (const ReferenceType *TargetRef = ParamType->getAs<ReferenceType>()) {
5767 T = Context.getQualifiedType(T,
5768 TargetRef->getPointeeType().getQualifiers());
5769 } else if (isa<FunctionDecl>(VD)) {
5770 // References to functions are always lvalues.
5774 return BuildDeclRefExpr(VD, T, VK, Loc);
5777 /// \brief Construct a new expression that refers to the given
5778 /// integral template argument with the given source-location
5781 /// This routine takes care of the mapping from an integral template
5782 /// argument (which may have any integral type) to the appropriate
5785 Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg,
5786 SourceLocation Loc) {
5787 assert(Arg.getKind() == TemplateArgument::Integral &&
5788 "Operation is only valid for integral template arguments");
5789 QualType OrigT = Arg.getIntegralType();
5791 // If this is an enum type that we're instantiating, we need to use an integer
5792 // type the same size as the enumerator. We don't want to build an
5793 // IntegerLiteral with enum type. The integer type of an enum type can be of
5794 // any integral type with C++11 enum classes, make sure we create the right
5795 // type of literal for it.
5797 if (const EnumType *ET = OrigT->getAs<EnumType>())
5798 T = ET->getDecl()->getIntegerType();
5801 if (T->isAnyCharacterType()) {
5802 // This does not need to handle u8 character literals because those are
5803 // of type char, and so can also be covered by an ASCII character literal.
5804 CharacterLiteral::CharacterKind Kind;
5805 if (T->isWideCharType())
5806 Kind = CharacterLiteral::Wide;
5807 else if (T->isChar16Type())
5808 Kind = CharacterLiteral::UTF16;
5809 else if (T->isChar32Type())
5810 Kind = CharacterLiteral::UTF32;
5812 Kind = CharacterLiteral::Ascii;
5814 E = new (Context) CharacterLiteral(Arg.getAsIntegral().getZExtValue(),
5816 } else if (T->isBooleanType()) {
5817 E = new (Context) CXXBoolLiteralExpr(Arg.getAsIntegral().getBoolValue(),
5819 } else if (T->isNullPtrType()) {
5820 E = new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
5822 E = IntegerLiteral::Create(Context, Arg.getAsIntegral(), T, Loc);
5825 if (OrigT->isEnumeralType()) {
5826 // FIXME: This is a hack. We need a better way to handle substituted
5827 // non-type template parameters.
5828 E = CStyleCastExpr::Create(Context, OrigT, VK_RValue, CK_IntegralCast, E,
5830 Context.getTrivialTypeSourceInfo(OrigT, Loc),
5837 static bool isDependentOnOuter(NonTypeTemplateParmDecl *NTTP) {
5838 if (NTTP->getDepth() == 0 || !NTTP->getType()->isDependentType())
5840 DependencyChecker Checker(NTTP->getDepth(), /*IgnoreNonTypeDependent*/ false,
5841 /*FindLessThanDepth*/ true);
5842 Checker.TraverseType(NTTP->getType());
5843 return Checker.Match;
5846 /// \brief Match two template parameters within template parameter lists.
5847 static bool MatchTemplateParameterKind(Sema &S, NamedDecl *New, NamedDecl *Old,
5849 Sema::TemplateParameterListEqualKind Kind,
5850 SourceLocation TemplateArgLoc) {
5851 // Check the actual kind (type, non-type, template).
5852 if (Old->getKind() != New->getKind()) {
5854 unsigned NextDiag = diag::err_template_param_different_kind;
5855 if (TemplateArgLoc.isValid()) {
5856 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
5857 NextDiag = diag::note_template_param_different_kind;
5859 S.Diag(New->getLocation(), NextDiag)
5860 << (Kind != Sema::TPL_TemplateMatch);
5861 S.Diag(Old->getLocation(), diag::note_template_prev_declaration)
5862 << (Kind != Sema::TPL_TemplateMatch);
5868 // Check that both are parameter packs or neither are parameter packs.
5869 // However, if we are matching a template template argument to a
5870 // template template parameter, the template template parameter can have
5871 // a parameter pack where the template template argument does not.
5872 if (Old->isTemplateParameterPack() != New->isTemplateParameterPack() &&
5873 !(Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
5874 Old->isTemplateParameterPack())) {
5876 unsigned NextDiag = diag::err_template_parameter_pack_non_pack;
5877 if (TemplateArgLoc.isValid()) {
5878 S.Diag(TemplateArgLoc,
5879 diag::err_template_arg_template_params_mismatch);
5880 NextDiag = diag::note_template_parameter_pack_non_pack;
5883 unsigned ParamKind = isa<TemplateTypeParmDecl>(New)? 0
5884 : isa<NonTypeTemplateParmDecl>(New)? 1
5886 S.Diag(New->getLocation(), NextDiag)
5887 << ParamKind << New->isParameterPack();
5888 S.Diag(Old->getLocation(), diag::note_template_parameter_pack_here)
5889 << ParamKind << Old->isParameterPack();
5895 // For non-type template parameters, check the type of the parameter.
5896 if (NonTypeTemplateParmDecl *OldNTTP
5897 = dyn_cast<NonTypeTemplateParmDecl>(Old)) {
5898 NonTypeTemplateParmDecl *NewNTTP = cast<NonTypeTemplateParmDecl>(New);
5900 // If we are matching a template template argument to a template
5901 // template parameter and one of the non-type template parameter types
5902 // is dependent on an outer template's parameter, then we must wait until
5903 // template instantiation time to actually compare the arguments.
5904 if (Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
5905 (isDependentOnOuter(OldNTTP) || isDependentOnOuter(NewNTTP)))
5908 if (!S.Context.hasSameType(OldNTTP->getType(), NewNTTP->getType())) {
5910 unsigned NextDiag = diag::err_template_nontype_parm_different_type;
5911 if (TemplateArgLoc.isValid()) {
5912 S.Diag(TemplateArgLoc,
5913 diag::err_template_arg_template_params_mismatch);
5914 NextDiag = diag::note_template_nontype_parm_different_type;
5916 S.Diag(NewNTTP->getLocation(), NextDiag)
5917 << NewNTTP->getType()
5918 << (Kind != Sema::TPL_TemplateMatch);
5919 S.Diag(OldNTTP->getLocation(),
5920 diag::note_template_nontype_parm_prev_declaration)
5921 << OldNTTP->getType();
5930 // For template template parameters, check the template parameter types.
5931 // The template parameter lists of template template
5932 // parameters must agree.
5933 if (TemplateTemplateParmDecl *OldTTP
5934 = dyn_cast<TemplateTemplateParmDecl>(Old)) {
5935 TemplateTemplateParmDecl *NewTTP = cast<TemplateTemplateParmDecl>(New);
5936 return S.TemplateParameterListsAreEqual(NewTTP->getTemplateParameters(),
5937 OldTTP->getTemplateParameters(),
5939 (Kind == Sema::TPL_TemplateMatch
5940 ? Sema::TPL_TemplateTemplateParmMatch
5948 /// \brief Diagnose a known arity mismatch when comparing template argument
5951 void DiagnoseTemplateParameterListArityMismatch(Sema &S,
5952 TemplateParameterList *New,
5953 TemplateParameterList *Old,
5954 Sema::TemplateParameterListEqualKind Kind,
5955 SourceLocation TemplateArgLoc) {
5956 unsigned NextDiag = diag::err_template_param_list_different_arity;
5957 if (TemplateArgLoc.isValid()) {
5958 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
5959 NextDiag = diag::note_template_param_list_different_arity;
5961 S.Diag(New->getTemplateLoc(), NextDiag)
5962 << (New->size() > Old->size())
5963 << (Kind != Sema::TPL_TemplateMatch)
5964 << SourceRange(New->getTemplateLoc(), New->getRAngleLoc());
5965 S.Diag(Old->getTemplateLoc(), diag::note_template_prev_declaration)
5966 << (Kind != Sema::TPL_TemplateMatch)
5967 << SourceRange(Old->getTemplateLoc(), Old->getRAngleLoc());
5970 /// \brief Determine whether the given template parameter lists are
5973 /// \param New The new template parameter list, typically written in the
5974 /// source code as part of a new template declaration.
5976 /// \param Old The old template parameter list, typically found via
5977 /// name lookup of the template declared with this template parameter
5980 /// \param Complain If true, this routine will produce a diagnostic if
5981 /// the template parameter lists are not equivalent.
5983 /// \param Kind describes how we are to match the template parameter lists.
5985 /// \param TemplateArgLoc If this source location is valid, then we
5986 /// are actually checking the template parameter list of a template
5987 /// argument (New) against the template parameter list of its
5988 /// corresponding template template parameter (Old). We produce
5989 /// slightly different diagnostics in this scenario.
5991 /// \returns True if the template parameter lists are equal, false
5994 Sema::TemplateParameterListsAreEqual(TemplateParameterList *New,
5995 TemplateParameterList *Old,
5997 TemplateParameterListEqualKind Kind,
5998 SourceLocation TemplateArgLoc) {
5999 if (Old->size() != New->size() && Kind != TPL_TemplateTemplateArgumentMatch) {
6001 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
6007 // C++0x [temp.arg.template]p3:
6008 // A template-argument matches a template template-parameter (call it P)
6009 // when each of the template parameters in the template-parameter-list of
6010 // the template-argument's corresponding class template or alias template
6011 // (call it A) matches the corresponding template parameter in the
6012 // template-parameter-list of P. [...]
6013 TemplateParameterList::iterator NewParm = New->begin();
6014 TemplateParameterList::iterator NewParmEnd = New->end();
6015 for (TemplateParameterList::iterator OldParm = Old->begin(),
6016 OldParmEnd = Old->end();
6017 OldParm != OldParmEnd; ++OldParm) {
6018 if (Kind != TPL_TemplateTemplateArgumentMatch ||
6019 !(*OldParm)->isTemplateParameterPack()) {
6020 if (NewParm == NewParmEnd) {
6022 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
6028 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
6029 Kind, TemplateArgLoc))
6036 // C++0x [temp.arg.template]p3:
6037 // [...] When P's template- parameter-list contains a template parameter
6038 // pack (14.5.3), the template parameter pack will match zero or more
6039 // template parameters or template parameter packs in the
6040 // template-parameter-list of A with the same type and form as the
6041 // template parameter pack in P (ignoring whether those template
6042 // parameters are template parameter packs).
6043 for (; NewParm != NewParmEnd; ++NewParm) {
6044 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
6045 Kind, TemplateArgLoc))
6050 // Make sure we exhausted all of the arguments.
6051 if (NewParm != NewParmEnd) {
6053 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
6062 /// \brief Check whether a template can be declared within this scope.
6064 /// If the template declaration is valid in this scope, returns
6065 /// false. Otherwise, issues a diagnostic and returns true.
6067 Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) {
6071 // Find the nearest enclosing declaration scope.
6072 while ((S->getFlags() & Scope::DeclScope) == 0 ||
6073 (S->getFlags() & Scope::TemplateParamScope) != 0)
6077 // A template [...] shall not have C linkage.
6078 DeclContext *Ctx = S->getEntity();
6079 if (Ctx && Ctx->isExternCContext()) {
6080 Diag(TemplateParams->getTemplateLoc(), diag::err_template_linkage)
6081 << TemplateParams->getSourceRange();
6082 if (const LinkageSpecDecl *LSD = Ctx->getExternCContext())
6083 Diag(LSD->getExternLoc(), diag::note_extern_c_begins_here);
6086 Ctx = Ctx->getRedeclContext();
6089 // A template-declaration can appear only as a namespace scope or
6090 // class scope declaration.
6092 if (Ctx->isFileContext())
6094 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Ctx)) {
6095 // C++ [temp.mem]p2:
6096 // A local class shall not have member templates.
6097 if (RD->isLocalClass())
6098 return Diag(TemplateParams->getTemplateLoc(),
6099 diag::err_template_inside_local_class)
6100 << TemplateParams->getSourceRange();
6106 return Diag(TemplateParams->getTemplateLoc(),
6107 diag::err_template_outside_namespace_or_class_scope)
6108 << TemplateParams->getSourceRange();
6111 /// \brief Determine what kind of template specialization the given declaration
6113 static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D) {
6115 return TSK_Undeclared;
6117 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D))
6118 return Record->getTemplateSpecializationKind();
6119 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D))
6120 return Function->getTemplateSpecializationKind();
6121 if (VarDecl *Var = dyn_cast<VarDecl>(D))
6122 return Var->getTemplateSpecializationKind();
6124 return TSK_Undeclared;
6127 /// \brief Check whether a specialization is well-formed in the current
6130 /// This routine determines whether a template specialization can be declared
6131 /// in the current context (C++ [temp.expl.spec]p2).
6133 /// \param S the semantic analysis object for which this check is being
6136 /// \param Specialized the entity being specialized or instantiated, which
6137 /// may be a kind of template (class template, function template, etc.) or
6138 /// a member of a class template (member function, static data member,
6141 /// \param PrevDecl the previous declaration of this entity, if any.
6143 /// \param Loc the location of the explicit specialization or instantiation of
6146 /// \param IsPartialSpecialization whether this is a partial specialization of
6147 /// a class template.
6149 /// \returns true if there was an error that we cannot recover from, false
6151 static bool CheckTemplateSpecializationScope(Sema &S,
6152 NamedDecl *Specialized,
6153 NamedDecl *PrevDecl,
6155 bool IsPartialSpecialization) {
6156 // Keep these "kind" numbers in sync with the %select statements in the
6157 // various diagnostics emitted by this routine.
6159 if (isa<ClassTemplateDecl>(Specialized))
6160 EntityKind = IsPartialSpecialization? 1 : 0;
6161 else if (isa<VarTemplateDecl>(Specialized))
6162 EntityKind = IsPartialSpecialization ? 3 : 2;
6163 else if (isa<FunctionTemplateDecl>(Specialized))
6165 else if (isa<CXXMethodDecl>(Specialized))
6167 else if (isa<VarDecl>(Specialized))
6169 else if (isa<RecordDecl>(Specialized))
6171 else if (isa<EnumDecl>(Specialized) && S.getLangOpts().CPlusPlus11)
6174 S.Diag(Loc, diag::err_template_spec_unknown_kind)
6175 << S.getLangOpts().CPlusPlus11;
6176 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
6180 // C++ [temp.expl.spec]p2:
6181 // An explicit specialization shall be declared in the namespace
6182 // of which the template is a member, or, for member templates, in
6183 // the namespace of which the enclosing class or enclosing class
6184 // template is a member. An explicit specialization of a member
6185 // function, member class or static data member of a class
6186 // template shall be declared in the namespace of which the class
6187 // template is a member. Such a declaration may also be a
6188 // definition. If the declaration is not a definition, the
6189 // specialization may be defined later in the name- space in which
6190 // the explicit specialization was declared, or in a namespace
6191 // that encloses the one in which the explicit specialization was
6193 if (S.CurContext->getRedeclContext()->isFunctionOrMethod()) {
6194 S.Diag(Loc, diag::err_template_spec_decl_function_scope)
6199 if (S.CurContext->isRecord() && !IsPartialSpecialization) {
6200 if (S.getLangOpts().MicrosoftExt) {
6201 // Do not warn for class scope explicit specialization during
6202 // instantiation, warning was already emitted during pattern
6203 // semantic analysis.
6204 if (!S.ActiveTemplateInstantiations.size())
6205 S.Diag(Loc, diag::ext_function_specialization_in_class)
6208 S.Diag(Loc, diag::err_template_spec_decl_class_scope)
6214 if (S.CurContext->isRecord() &&
6215 !S.CurContext->Equals(Specialized->getDeclContext())) {
6216 // Make sure that we're specializing in the right record context.
6217 // Otherwise, things can go horribly wrong.
6218 S.Diag(Loc, diag::err_template_spec_decl_class_scope)
6223 // C++ [temp.class.spec]p6:
6224 // A class template partial specialization may be declared or redeclared
6225 // in any namespace scope in which its definition may be defined (14.5.1
6227 DeclContext *SpecializedContext
6228 = Specialized->getDeclContext()->getEnclosingNamespaceContext();
6229 DeclContext *DC = S.CurContext->getEnclosingNamespaceContext();
6231 // Make sure that this redeclaration (or definition) occurs in an enclosing
6233 // Note that HandleDeclarator() performs this check for explicit
6234 // specializations of function templates, static data members, and member
6235 // functions, so we skip the check here for those kinds of entities.
6236 // FIXME: HandleDeclarator's diagnostics aren't quite as good, though.
6237 // Should we refactor that check, so that it occurs later?
6238 if (!DC->Encloses(SpecializedContext) &&
6239 !(isa<FunctionTemplateDecl>(Specialized) ||
6240 isa<FunctionDecl>(Specialized) ||
6241 isa<VarTemplateDecl>(Specialized) ||
6242 isa<VarDecl>(Specialized))) {
6243 if (isa<TranslationUnitDecl>(SpecializedContext))
6244 S.Diag(Loc, diag::err_template_spec_redecl_global_scope)
6245 << EntityKind << Specialized;
6246 else if (isa<NamespaceDecl>(SpecializedContext)) {
6247 int Diag = diag::err_template_spec_redecl_out_of_scope;
6248 if (S.getLangOpts().MicrosoftExt)
6249 Diag = diag::ext_ms_template_spec_redecl_out_of_scope;
6250 S.Diag(Loc, Diag) << EntityKind << Specialized
6251 << cast<NamedDecl>(SpecializedContext);
6253 llvm_unreachable("unexpected namespace context for specialization");
6255 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
6256 } else if ((!PrevDecl ||
6257 getTemplateSpecializationKind(PrevDecl) == TSK_Undeclared ||
6258 getTemplateSpecializationKind(PrevDecl) ==
6259 TSK_ImplicitInstantiation)) {
6260 // C++ [temp.exp.spec]p2:
6261 // An explicit specialization shall be declared in the namespace of which
6262 // the template is a member, or, for member templates, in the namespace
6263 // of which the enclosing class or enclosing class template is a member.
6264 // An explicit specialization of a member function, member class or
6265 // static data member of a class template shall be declared in the
6266 // namespace of which the class template is a member.
6268 // C++11 [temp.expl.spec]p2:
6269 // An explicit specialization shall be declared in a namespace enclosing
6270 // the specialized template.
6271 // C++11 [temp.explicit]p3:
6272 // An explicit instantiation shall appear in an enclosing namespace of its
6274 if (!DC->InEnclosingNamespaceSetOf(SpecializedContext)) {
6275 bool IsCPlusPlus11Extension = DC->Encloses(SpecializedContext);
6276 if (isa<TranslationUnitDecl>(SpecializedContext)) {
6277 assert(!IsCPlusPlus11Extension &&
6278 "DC encloses TU but isn't in enclosing namespace set");
6279 S.Diag(Loc, diag::err_template_spec_decl_out_of_scope_global)
6280 << EntityKind << Specialized;
6281 } else if (isa<NamespaceDecl>(SpecializedContext)) {
6283 if (!IsCPlusPlus11Extension)
6284 Diag = diag::err_template_spec_decl_out_of_scope;
6285 else if (!S.getLangOpts().CPlusPlus11)
6286 Diag = diag::ext_template_spec_decl_out_of_scope;
6288 Diag = diag::warn_cxx98_compat_template_spec_decl_out_of_scope;
6290 << EntityKind << Specialized << cast<NamedDecl>(SpecializedContext);
6293 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
6300 static SourceRange findTemplateParameterInType(unsigned Depth, Expr *E) {
6301 if (!E->isTypeDependent())
6302 return SourceLocation();
6303 DependencyChecker Checker(Depth, /*IgnoreNonTypeDependent*/true);
6304 Checker.TraverseStmt(E);
6305 if (Checker.MatchLoc.isInvalid())
6306 return E->getSourceRange();
6307 return Checker.MatchLoc;
6310 static SourceRange findTemplateParameter(unsigned Depth, TypeLoc TL) {
6311 if (!TL.getType()->isDependentType())
6312 return SourceLocation();
6313 DependencyChecker Checker(Depth, /*IgnoreNonTypeDependent*/true);
6314 Checker.TraverseTypeLoc(TL);
6315 if (Checker.MatchLoc.isInvalid())
6316 return TL.getSourceRange();
6317 return Checker.MatchLoc;
6320 /// \brief Subroutine of Sema::CheckTemplatePartialSpecializationArgs
6321 /// that checks non-type template partial specialization arguments.
6322 static bool CheckNonTypeTemplatePartialSpecializationArgs(
6323 Sema &S, SourceLocation TemplateNameLoc, NonTypeTemplateParmDecl *Param,
6324 const TemplateArgument *Args, unsigned NumArgs, bool IsDefaultArgument) {
6325 for (unsigned I = 0; I != NumArgs; ++I) {
6326 if (Args[I].getKind() == TemplateArgument::Pack) {
6327 if (CheckNonTypeTemplatePartialSpecializationArgs(
6328 S, TemplateNameLoc, Param, Args[I].pack_begin(),
6329 Args[I].pack_size(), IsDefaultArgument))
6335 if (Args[I].getKind() != TemplateArgument::Expression)
6338 Expr *ArgExpr = Args[I].getAsExpr();
6340 // We can have a pack expansion of any of the bullets below.
6341 if (PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(ArgExpr))
6342 ArgExpr = Expansion->getPattern();
6344 // Strip off any implicit casts we added as part of type checking.
6345 while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
6346 ArgExpr = ICE->getSubExpr();
6348 // C++ [temp.class.spec]p8:
6349 // A non-type argument is non-specialized if it is the name of a
6350 // non-type parameter. All other non-type arguments are
6353 // Below, we check the two conditions that only apply to
6354 // specialized non-type arguments, so skip any non-specialized
6356 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ArgExpr))
6357 if (isa<NonTypeTemplateParmDecl>(DRE->getDecl()))
6360 // C++ [temp.class.spec]p9:
6361 // Within the argument list of a class template partial
6362 // specialization, the following restrictions apply:
6363 // -- A partially specialized non-type argument expression
6364 // shall not involve a template parameter of the partial
6365 // specialization except when the argument expression is a
6366 // simple identifier.
6367 // -- The type of a template parameter corresponding to a
6368 // specialized non-type argument shall not be dependent on a
6369 // parameter of the specialization.
6370 // DR1315 removes the first bullet, leaving an incoherent set of rules.
6371 // We implement a compromise between the original rules and DR1315:
6372 // -- A specialized non-type template argument shall not be
6373 // type-dependent and the corresponding template parameter
6374 // shall have a non-dependent type.
6375 SourceRange ParamUseRange =
6376 findTemplateParameterInType(Param->getDepth(), ArgExpr);
6377 if (ParamUseRange.isValid()) {
6378 if (IsDefaultArgument) {
6379 S.Diag(TemplateNameLoc,
6380 diag::err_dependent_non_type_arg_in_partial_spec);
6381 S.Diag(ParamUseRange.getBegin(),
6382 diag::note_dependent_non_type_default_arg_in_partial_spec)
6385 S.Diag(ParamUseRange.getBegin(),
6386 diag::err_dependent_non_type_arg_in_partial_spec)
6392 ParamUseRange = findTemplateParameter(
6393 Param->getDepth(), Param->getTypeSourceInfo()->getTypeLoc());
6394 if (ParamUseRange.isValid()) {
6395 S.Diag(IsDefaultArgument ? TemplateNameLoc : ArgExpr->getLocStart(),
6396 diag::err_dependent_typed_non_type_arg_in_partial_spec)
6397 << Param->getType();
6398 S.Diag(Param->getLocation(), diag::note_template_param_here)
6399 << (IsDefaultArgument ? ParamUseRange : SourceRange())
6408 /// \brief Check the non-type template arguments of a class template
6409 /// partial specialization according to C++ [temp.class.spec]p9.
6411 /// \param TemplateNameLoc the location of the template name.
6412 /// \param PrimaryTemplate the template parameters of the primary class
6414 /// \param NumExplicit the number of explicitly-specified template arguments.
6415 /// \param TemplateArgs the template arguments of the class template
6416 /// partial specialization.
6418 /// \returns \c true if there was an error, \c false otherwise.
6419 bool Sema::CheckTemplatePartialSpecializationArgs(
6420 SourceLocation TemplateNameLoc, TemplateDecl *PrimaryTemplate,
6421 unsigned NumExplicit, ArrayRef<TemplateArgument> TemplateArgs) {
6422 // We have to be conservative when checking a template in a dependent
6424 if (PrimaryTemplate->getDeclContext()->isDependentContext())
6427 TemplateParameterList *TemplateParams =
6428 PrimaryTemplate->getTemplateParameters();
6429 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
6430 NonTypeTemplateParmDecl *Param
6431 = dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(I));
6435 if (CheckNonTypeTemplatePartialSpecializationArgs(*this, TemplateNameLoc,
6436 Param, &TemplateArgs[I],
6437 1, I >= NumExplicit))
6445 Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec,
6447 SourceLocation KWLoc,
6448 SourceLocation ModulePrivateLoc,
6449 TemplateIdAnnotation &TemplateId,
6450 AttributeList *Attr,
6451 MultiTemplateParamsArg
6452 TemplateParameterLists,
6453 SkipBodyInfo *SkipBody) {
6454 assert(TUK != TUK_Reference && "References are not specializations");
6456 CXXScopeSpec &SS = TemplateId.SS;
6458 // NOTE: KWLoc is the location of the tag keyword. This will instead
6459 // store the location of the outermost template keyword in the declaration.
6460 SourceLocation TemplateKWLoc = TemplateParameterLists.size() > 0
6461 ? TemplateParameterLists[0]->getTemplateLoc() : KWLoc;
6462 SourceLocation TemplateNameLoc = TemplateId.TemplateNameLoc;
6463 SourceLocation LAngleLoc = TemplateId.LAngleLoc;
6464 SourceLocation RAngleLoc = TemplateId.RAngleLoc;
6466 // Find the class template we're specializing
6467 TemplateName Name = TemplateId.Template.get();
6468 ClassTemplateDecl *ClassTemplate
6469 = dyn_cast_or_null<ClassTemplateDecl>(Name.getAsTemplateDecl());
6471 if (!ClassTemplate) {
6472 Diag(TemplateNameLoc, diag::err_not_class_template_specialization)
6473 << (Name.getAsTemplateDecl() &&
6474 isa<TemplateTemplateParmDecl>(Name.getAsTemplateDecl()));
6478 bool isExplicitSpecialization = false;
6479 bool isPartialSpecialization = false;
6481 // Check the validity of the template headers that introduce this
6483 // FIXME: We probably shouldn't complain about these headers for
6484 // friend declarations.
6485 bool Invalid = false;
6486 TemplateParameterList *TemplateParams =
6487 MatchTemplateParametersToScopeSpecifier(
6488 KWLoc, TemplateNameLoc, SS, &TemplateId,
6489 TemplateParameterLists, TUK == TUK_Friend, isExplicitSpecialization,
6494 if (TemplateParams && TemplateParams->size() > 0) {
6495 isPartialSpecialization = true;
6497 if (TUK == TUK_Friend) {
6498 Diag(KWLoc, diag::err_partial_specialization_friend)
6499 << SourceRange(LAngleLoc, RAngleLoc);
6503 // C++ [temp.class.spec]p10:
6504 // The template parameter list of a specialization shall not
6505 // contain default template argument values.
6506 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
6507 Decl *Param = TemplateParams->getParam(I);
6508 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) {
6509 if (TTP->hasDefaultArgument()) {
6510 Diag(TTP->getDefaultArgumentLoc(),
6511 diag::err_default_arg_in_partial_spec);
6512 TTP->removeDefaultArgument();
6514 } else if (NonTypeTemplateParmDecl *NTTP
6515 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
6516 if (Expr *DefArg = NTTP->getDefaultArgument()) {
6517 Diag(NTTP->getDefaultArgumentLoc(),
6518 diag::err_default_arg_in_partial_spec)
6519 << DefArg->getSourceRange();
6520 NTTP->removeDefaultArgument();
6523 TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(Param);
6524 if (TTP->hasDefaultArgument()) {
6525 Diag(TTP->getDefaultArgument().getLocation(),
6526 diag::err_default_arg_in_partial_spec)
6527 << TTP->getDefaultArgument().getSourceRange();
6528 TTP->removeDefaultArgument();
6532 } else if (TemplateParams) {
6533 if (TUK == TUK_Friend)
6534 Diag(KWLoc, diag::err_template_spec_friend)
6535 << FixItHint::CreateRemoval(
6536 SourceRange(TemplateParams->getTemplateLoc(),
6537 TemplateParams->getRAngleLoc()))
6538 << SourceRange(LAngleLoc, RAngleLoc);
6540 isExplicitSpecialization = true;
6542 assert(TUK == TUK_Friend && "should have a 'template<>' for this decl");
6545 // Check that the specialization uses the same tag kind as the
6546 // original template.
6547 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
6548 assert(Kind != TTK_Enum && "Invalid enum tag in class template spec!");
6549 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
6550 Kind, TUK == TUK_Definition, KWLoc,
6551 ClassTemplate->getIdentifier())) {
6552 Diag(KWLoc, diag::err_use_with_wrong_tag)
6554 << FixItHint::CreateReplacement(KWLoc,
6555 ClassTemplate->getTemplatedDecl()->getKindName());
6556 Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
6557 diag::note_previous_use);
6558 Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
6561 // Translate the parser's template argument list in our AST format.
6562 TemplateArgumentListInfo TemplateArgs =
6563 makeTemplateArgumentListInfo(*this, TemplateId);
6565 // Check for unexpanded parameter packs in any of the template arguments.
6566 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
6567 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
6568 UPPC_PartialSpecialization))
6571 // Check that the template argument list is well-formed for this
6573 SmallVector<TemplateArgument, 4> Converted;
6574 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
6575 TemplateArgs, false, Converted))
6578 // Find the class template (partial) specialization declaration that
6579 // corresponds to these arguments.
6580 if (isPartialSpecialization) {
6581 if (CheckTemplatePartialSpecializationArgs(TemplateNameLoc, ClassTemplate,
6582 TemplateArgs.size(), Converted))
6585 // FIXME: Move this to CheckTemplatePartialSpecializationArgs so we
6586 // also do it during instantiation.
6587 bool InstantiationDependent;
6588 if (!Name.isDependent() &&
6589 !TemplateSpecializationType::anyDependentTemplateArguments(
6590 TemplateArgs.arguments(), InstantiationDependent)) {
6591 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
6592 << ClassTemplate->getDeclName();
6593 isPartialSpecialization = false;
6597 void *InsertPos = nullptr;
6598 ClassTemplateSpecializationDecl *PrevDecl = nullptr;
6600 if (isPartialSpecialization)
6601 // FIXME: Template parameter list matters, too
6602 PrevDecl = ClassTemplate->findPartialSpecialization(Converted, InsertPos);
6604 PrevDecl = ClassTemplate->findSpecialization(Converted, InsertPos);
6606 ClassTemplateSpecializationDecl *Specialization = nullptr;
6608 // Check whether we can declare a class template specialization in
6609 // the current scope.
6610 if (TUK != TUK_Friend &&
6611 CheckTemplateSpecializationScope(*this, ClassTemplate, PrevDecl,
6613 isPartialSpecialization))
6616 // The canonical type
6618 if (isPartialSpecialization) {
6619 // Build the canonical type that describes the converted template
6620 // arguments of the class template partial specialization.
6621 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
6622 CanonType = Context.getTemplateSpecializationType(CanonTemplate,
6625 if (Context.hasSameType(CanonType,
6626 ClassTemplate->getInjectedClassNameSpecialization())) {
6627 // C++ [temp.class.spec]p9b3:
6629 // -- The argument list of the specialization shall not be identical
6630 // to the implicit argument list of the primary template.
6632 // This rule has since been removed, because it's redundant given DR1495,
6633 // but we keep it because it produces better diagnostics and recovery.
6634 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
6635 << /*class template*/0 << (TUK == TUK_Definition)
6636 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
6637 return CheckClassTemplate(S, TagSpec, TUK, KWLoc, SS,
6638 ClassTemplate->getIdentifier(),
6642 AS_none, /*ModulePrivateLoc=*/SourceLocation(),
6643 /*FriendLoc*/SourceLocation(),
6644 TemplateParameterLists.size() - 1,
6645 TemplateParameterLists.data());
6648 // Create a new class template partial specialization declaration node.
6649 ClassTemplatePartialSpecializationDecl *PrevPartial
6650 = cast_or_null<ClassTemplatePartialSpecializationDecl>(PrevDecl);
6651 ClassTemplatePartialSpecializationDecl *Partial
6652 = ClassTemplatePartialSpecializationDecl::Create(Context, Kind,
6653 ClassTemplate->getDeclContext(),
6654 KWLoc, TemplateNameLoc,
6661 SetNestedNameSpecifier(Partial, SS);
6662 if (TemplateParameterLists.size() > 1 && SS.isSet()) {
6663 Partial->setTemplateParameterListsInfo(
6664 Context, TemplateParameterLists.drop_back(1));
6668 ClassTemplate->AddPartialSpecialization(Partial, InsertPos);
6669 Specialization = Partial;
6671 // If we are providing an explicit specialization of a member class
6672 // template specialization, make a note of that.
6673 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
6674 PrevPartial->setMemberSpecialization();
6676 CheckTemplatePartialSpecialization(Partial);
6678 // Create a new class template specialization declaration node for
6679 // this explicit specialization or friend declaration.
6681 = ClassTemplateSpecializationDecl::Create(Context, Kind,
6682 ClassTemplate->getDeclContext(),
6683 KWLoc, TemplateNameLoc,
6687 SetNestedNameSpecifier(Specialization, SS);
6688 if (TemplateParameterLists.size() > 0) {
6689 Specialization->setTemplateParameterListsInfo(Context,
6690 TemplateParameterLists);
6694 ClassTemplate->AddSpecialization(Specialization, InsertPos);
6696 if (CurContext->isDependentContext()) {
6697 // -fms-extensions permits specialization of nested classes without
6698 // fully specializing the outer class(es).
6699 assert(getLangOpts().MicrosoftExt &&
6700 "Only possible with -fms-extensions!");
6701 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
6702 CanonType = Context.getTemplateSpecializationType(
6703 CanonTemplate, Converted);
6705 CanonType = Context.getTypeDeclType(Specialization);
6709 // C++ [temp.expl.spec]p6:
6710 // If a template, a member template or the member of a class template is
6711 // explicitly specialized then that specialization shall be declared
6712 // before the first use of that specialization that would cause an implicit
6713 // instantiation to take place, in every translation unit in which such a
6714 // use occurs; no diagnostic is required.
6715 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
6717 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6718 // Is there any previous explicit specialization declaration?
6719 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
6726 SourceRange Range(TemplateNameLoc, RAngleLoc);
6727 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
6728 << Context.getTypeDeclType(Specialization) << Range;
6730 Diag(PrevDecl->getPointOfInstantiation(),
6731 diag::note_instantiation_required_here)
6732 << (PrevDecl->getTemplateSpecializationKind()
6733 != TSK_ImplicitInstantiation);
6738 // If this is not a friend, note that this is an explicit specialization.
6739 if (TUK != TUK_Friend)
6740 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
6742 // Check that this isn't a redefinition of this specialization.
6743 if (TUK == TUK_Definition) {
6744 RecordDecl *Def = Specialization->getDefinition();
6745 NamedDecl *Hidden = nullptr;
6746 if (Def && SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
6747 SkipBody->ShouldSkip = true;
6748 makeMergedDefinitionVisible(Hidden, KWLoc);
6749 // From here on out, treat this as just a redeclaration.
6750 TUK = TUK_Declaration;
6752 SourceRange Range(TemplateNameLoc, RAngleLoc);
6753 Diag(TemplateNameLoc, diag::err_redefinition) << Specialization << Range;
6754 Diag(Def->getLocation(), diag::note_previous_definition);
6755 Specialization->setInvalidDecl();
6761 ProcessDeclAttributeList(S, Specialization, Attr);
6763 // Add alignment attributes if necessary; these attributes are checked when
6764 // the ASTContext lays out the structure.
6765 if (TUK == TUK_Definition) {
6766 AddAlignmentAttributesForRecord(Specialization);
6767 AddMsStructLayoutForRecord(Specialization);
6770 if (ModulePrivateLoc.isValid())
6771 Diag(Specialization->getLocation(), diag::err_module_private_specialization)
6772 << (isPartialSpecialization? 1 : 0)
6773 << FixItHint::CreateRemoval(ModulePrivateLoc);
6775 // Build the fully-sugared type for this class template
6776 // specialization as the user wrote in the specialization
6777 // itself. This means that we'll pretty-print the type retrieved
6778 // from the specialization's declaration the way that the user
6779 // actually wrote the specialization, rather than formatting the
6780 // name based on the "canonical" representation used to store the
6781 // template arguments in the specialization.
6782 TypeSourceInfo *WrittenTy
6783 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
6784 TemplateArgs, CanonType);
6785 if (TUK != TUK_Friend) {
6786 Specialization->setTypeAsWritten(WrittenTy);
6787 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
6790 // C++ [temp.expl.spec]p9:
6791 // A template explicit specialization is in the scope of the
6792 // namespace in which the template was defined.
6794 // We actually implement this paragraph where we set the semantic
6795 // context (in the creation of the ClassTemplateSpecializationDecl),
6796 // but we also maintain the lexical context where the actual
6797 // definition occurs.
6798 Specialization->setLexicalDeclContext(CurContext);
6800 // We may be starting the definition of this specialization.
6801 if (TUK == TUK_Definition)
6802 Specialization->startDefinition();
6804 if (TUK == TUK_Friend) {
6805 FriendDecl *Friend = FriendDecl::Create(Context, CurContext,
6809 Friend->setAccess(AS_public);
6810 CurContext->addDecl(Friend);
6812 // Add the specialization into its lexical context, so that it can
6813 // be seen when iterating through the list of declarations in that
6814 // context. However, specializations are not found by name lookup.
6815 CurContext->addDecl(Specialization);
6817 return Specialization;
6820 Decl *Sema::ActOnTemplateDeclarator(Scope *S,
6821 MultiTemplateParamsArg TemplateParameterLists,
6823 Decl *NewDecl = HandleDeclarator(S, D, TemplateParameterLists);
6824 ActOnDocumentableDecl(NewDecl);
6828 /// \brief Strips various properties off an implicit instantiation
6829 /// that has just been explicitly specialized.
6830 static void StripImplicitInstantiation(NamedDecl *D) {
6831 D->dropAttr<DLLImportAttr>();
6832 D->dropAttr<DLLExportAttr>();
6834 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
6835 FD->setInlineSpecified(false);
6838 /// \brief Compute the diagnostic location for an explicit instantiation
6839 // declaration or definition.
6840 static SourceLocation DiagLocForExplicitInstantiation(
6841 NamedDecl* D, SourceLocation PointOfInstantiation) {
6842 // Explicit instantiations following a specialization have no effect and
6843 // hence no PointOfInstantiation. In that case, walk decl backwards
6844 // until a valid name loc is found.
6845 SourceLocation PrevDiagLoc = PointOfInstantiation;
6846 for (Decl *Prev = D; Prev && !PrevDiagLoc.isValid();
6847 Prev = Prev->getPreviousDecl()) {
6848 PrevDiagLoc = Prev->getLocation();
6850 assert(PrevDiagLoc.isValid() &&
6851 "Explicit instantiation without point of instantiation?");
6855 /// \brief Diagnose cases where we have an explicit template specialization
6856 /// before/after an explicit template instantiation, producing diagnostics
6857 /// for those cases where they are required and determining whether the
6858 /// new specialization/instantiation will have any effect.
6860 /// \param NewLoc the location of the new explicit specialization or
6863 /// \param NewTSK the kind of the new explicit specialization or instantiation.
6865 /// \param PrevDecl the previous declaration of the entity.
6867 /// \param PrevTSK the kind of the old explicit specialization or instantiatin.
6869 /// \param PrevPointOfInstantiation if valid, indicates where the previus
6870 /// declaration was instantiated (either implicitly or explicitly).
6872 /// \param HasNoEffect will be set to true to indicate that the new
6873 /// specialization or instantiation has no effect and should be ignored.
6875 /// \returns true if there was an error that should prevent the introduction of
6876 /// the new declaration into the AST, false otherwise.
6878 Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc,
6879 TemplateSpecializationKind NewTSK,
6880 NamedDecl *PrevDecl,
6881 TemplateSpecializationKind PrevTSK,
6882 SourceLocation PrevPointOfInstantiation,
6883 bool &HasNoEffect) {
6884 HasNoEffect = false;
6887 case TSK_Undeclared:
6888 case TSK_ImplicitInstantiation:
6890 (PrevTSK == TSK_Undeclared || PrevTSK == TSK_ImplicitInstantiation) &&
6891 "previous declaration must be implicit!");
6894 case TSK_ExplicitSpecialization:
6896 case TSK_Undeclared:
6897 case TSK_ExplicitSpecialization:
6898 // Okay, we're just specializing something that is either already
6899 // explicitly specialized or has merely been mentioned without any
6903 case TSK_ImplicitInstantiation:
6904 if (PrevPointOfInstantiation.isInvalid()) {
6905 // The declaration itself has not actually been instantiated, so it is
6906 // still okay to specialize it.
6907 StripImplicitInstantiation(PrevDecl);
6912 case TSK_ExplicitInstantiationDeclaration:
6913 case TSK_ExplicitInstantiationDefinition:
6914 assert((PrevTSK == TSK_ImplicitInstantiation ||
6915 PrevPointOfInstantiation.isValid()) &&
6916 "Explicit instantiation without point of instantiation?");
6918 // C++ [temp.expl.spec]p6:
6919 // If a template, a member template or the member of a class template
6920 // is explicitly specialized then that specialization shall be declared
6921 // before the first use of that specialization that would cause an
6922 // implicit instantiation to take place, in every translation unit in
6923 // which such a use occurs; no diagnostic is required.
6924 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6925 // Is there any previous explicit specialization declaration?
6926 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization)
6930 Diag(NewLoc, diag::err_specialization_after_instantiation)
6932 Diag(PrevPointOfInstantiation, diag::note_instantiation_required_here)
6933 << (PrevTSK != TSK_ImplicitInstantiation);
6938 case TSK_ExplicitInstantiationDeclaration:
6940 case TSK_ExplicitInstantiationDeclaration:
6941 // This explicit instantiation declaration is redundant (that's okay).
6945 case TSK_Undeclared:
6946 case TSK_ImplicitInstantiation:
6947 // We're explicitly instantiating something that may have already been
6948 // implicitly instantiated; that's fine.
6951 case TSK_ExplicitSpecialization:
6952 // C++0x [temp.explicit]p4:
6953 // For a given set of template parameters, if an explicit instantiation
6954 // of a template appears after a declaration of an explicit
6955 // specialization for that template, the explicit instantiation has no
6960 case TSK_ExplicitInstantiationDefinition:
6961 // C++0x [temp.explicit]p10:
6962 // If an entity is the subject of both an explicit instantiation
6963 // declaration and an explicit instantiation definition in the same
6964 // translation unit, the definition shall follow the declaration.
6966 diag::err_explicit_instantiation_declaration_after_definition);
6968 // Explicit instantiations following a specialization have no effect and
6969 // hence no PrevPointOfInstantiation. In that case, walk decl backwards
6970 // until a valid name loc is found.
6971 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
6972 diag::note_explicit_instantiation_definition_here);
6977 case TSK_ExplicitInstantiationDefinition:
6979 case TSK_Undeclared:
6980 case TSK_ImplicitInstantiation:
6981 // We're explicitly instantiating something that may have already been
6982 // implicitly instantiated; that's fine.
6985 case TSK_ExplicitSpecialization:
6986 // C++ DR 259, C++0x [temp.explicit]p4:
6987 // For a given set of template parameters, if an explicit
6988 // instantiation of a template appears after a declaration of
6989 // an explicit specialization for that template, the explicit
6990 // instantiation has no effect.
6991 Diag(NewLoc, diag::warn_explicit_instantiation_after_specialization)
6993 Diag(PrevDecl->getLocation(),
6994 diag::note_previous_template_specialization);
6998 case TSK_ExplicitInstantiationDeclaration:
6999 // We're explicity instantiating a definition for something for which we
7000 // were previously asked to suppress instantiations. That's fine.
7002 // C++0x [temp.explicit]p4:
7003 // For a given set of template parameters, if an explicit instantiation
7004 // of a template appears after a declaration of an explicit
7005 // specialization for that template, the explicit instantiation has no
7007 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
7008 // Is there any previous explicit specialization declaration?
7009 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
7017 case TSK_ExplicitInstantiationDefinition:
7018 // C++0x [temp.spec]p5:
7019 // For a given template and a given set of template-arguments,
7020 // - an explicit instantiation definition shall appear at most once
7023 // MSVCCompat: MSVC silently ignores duplicate explicit instantiations.
7024 Diag(NewLoc, (getLangOpts().MSVCCompat)
7025 ? diag::ext_explicit_instantiation_duplicate
7026 : diag::err_explicit_instantiation_duplicate)
7028 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
7029 diag::note_previous_explicit_instantiation);
7035 llvm_unreachable("Missing specialization/instantiation case?");
7038 /// \brief Perform semantic analysis for the given dependent function
7039 /// template specialization.
7041 /// The only possible way to get a dependent function template specialization
7042 /// is with a friend declaration, like so:
7045 /// template \<class T> void foo(T);
7046 /// template \<class T> class A {
7047 /// friend void foo<>(T);
7051 /// There really isn't any useful analysis we can do here, so we
7052 /// just store the information.
7054 Sema::CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD,
7055 const TemplateArgumentListInfo &ExplicitTemplateArgs,
7056 LookupResult &Previous) {
7057 // Remove anything from Previous that isn't a function template in
7058 // the correct context.
7059 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
7060 LookupResult::Filter F = Previous.makeFilter();
7061 while (F.hasNext()) {
7062 NamedDecl *D = F.next()->getUnderlyingDecl();
7063 if (!isa<FunctionTemplateDecl>(D) ||
7064 !FDLookupContext->InEnclosingNamespaceSetOf(
7065 D->getDeclContext()->getRedeclContext()))
7070 // Should this be diagnosed here?
7071 if (Previous.empty()) return true;
7073 FD->setDependentTemplateSpecialization(Context, Previous.asUnresolvedSet(),
7074 ExplicitTemplateArgs);
7078 /// \brief Perform semantic analysis for the given function template
7081 /// This routine performs all of the semantic analysis required for an
7082 /// explicit function template specialization. On successful completion,
7083 /// the function declaration \p FD will become a function template
7086 /// \param FD the function declaration, which will be updated to become a
7087 /// function template specialization.
7089 /// \param ExplicitTemplateArgs the explicitly-provided template arguments,
7090 /// if any. Note that this may be valid info even when 0 arguments are
7091 /// explicitly provided as in, e.g., \c void sort<>(char*, char*);
7092 /// as it anyway contains info on the angle brackets locations.
7094 /// \param Previous the set of declarations that may be specialized by
7095 /// this function specialization.
7096 bool Sema::CheckFunctionTemplateSpecialization(
7097 FunctionDecl *FD, TemplateArgumentListInfo *ExplicitTemplateArgs,
7098 LookupResult &Previous) {
7099 // The set of function template specializations that could match this
7100 // explicit function template specialization.
7101 UnresolvedSet<8> Candidates;
7102 TemplateSpecCandidateSet FailedCandidates(FD->getLocation(),
7103 /*ForTakingAddress=*/false);
7105 llvm::SmallDenseMap<FunctionDecl *, TemplateArgumentListInfo, 8>
7106 ConvertedTemplateArgs;
7108 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
7109 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
7111 NamedDecl *Ovl = (*I)->getUnderlyingDecl();
7112 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Ovl)) {
7113 // Only consider templates found within the same semantic lookup scope as
7115 if (!FDLookupContext->InEnclosingNamespaceSetOf(
7116 Ovl->getDeclContext()->getRedeclContext()))
7119 // When matching a constexpr member function template specialization
7120 // against the primary template, we don't yet know whether the
7121 // specialization has an implicit 'const' (because we don't know whether
7122 // it will be a static member function until we know which template it
7123 // specializes), so adjust it now assuming it specializes this template.
7124 QualType FT = FD->getType();
7125 if (FD->isConstexpr()) {
7126 CXXMethodDecl *OldMD =
7127 dyn_cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl());
7128 if (OldMD && OldMD->isConst()) {
7129 const FunctionProtoType *FPT = FT->castAs<FunctionProtoType>();
7130 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
7131 EPI.TypeQuals |= Qualifiers::Const;
7132 FT = Context.getFunctionType(FPT->getReturnType(),
7133 FPT->getParamTypes(), EPI);
7137 TemplateArgumentListInfo Args;
7138 if (ExplicitTemplateArgs)
7139 Args = *ExplicitTemplateArgs;
7141 // C++ [temp.expl.spec]p11:
7142 // A trailing template-argument can be left unspecified in the
7143 // template-id naming an explicit function template specialization
7144 // provided it can be deduced from the function argument type.
7145 // Perform template argument deduction to determine whether we may be
7146 // specializing this template.
7147 // FIXME: It is somewhat wasteful to build
7148 TemplateDeductionInfo Info(FailedCandidates.getLocation());
7149 FunctionDecl *Specialization = nullptr;
7150 if (TemplateDeductionResult TDK = DeduceTemplateArguments(
7151 cast<FunctionTemplateDecl>(FunTmpl->getFirstDecl()),
7152 ExplicitTemplateArgs ? &Args : nullptr, FT, Specialization,
7154 // Template argument deduction failed; record why it failed, so
7155 // that we can provide nifty diagnostics.
7156 FailedCandidates.addCandidate().set(
7157 I.getPair(), FunTmpl->getTemplatedDecl(),
7158 MakeDeductionFailureInfo(Context, TDK, Info));
7163 // Target attributes are part of the cuda function signature, so
7164 // the deduced template's cuda target must match that of the
7165 // specialization. Given that C++ template deduction does not
7166 // take target attributes into account, we reject candidates
7167 // here that have a different target.
7168 if (LangOpts.CUDA &&
7169 IdentifyCUDATarget(Specialization,
7170 /* IgnoreImplicitHDAttributes = */ true) !=
7171 IdentifyCUDATarget(FD, /* IgnoreImplicitHDAttributes = */ true)) {
7172 FailedCandidates.addCandidate().set(
7173 I.getPair(), FunTmpl->getTemplatedDecl(),
7174 MakeDeductionFailureInfo(Context, TDK_CUDATargetMismatch, Info));
7178 // Record this candidate.
7179 if (ExplicitTemplateArgs)
7180 ConvertedTemplateArgs[Specialization] = std::move(Args);
7181 Candidates.addDecl(Specialization, I.getAccess());
7185 // Find the most specialized function template.
7186 UnresolvedSetIterator Result = getMostSpecialized(
7187 Candidates.begin(), Candidates.end(), FailedCandidates,
7189 PDiag(diag::err_function_template_spec_no_match) << FD->getDeclName(),
7190 PDiag(diag::err_function_template_spec_ambiguous)
7191 << FD->getDeclName() << (ExplicitTemplateArgs != nullptr),
7192 PDiag(diag::note_function_template_spec_matched));
7194 if (Result == Candidates.end())
7197 // Ignore access information; it doesn't figure into redeclaration checking.
7198 FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
7200 // C++ Concepts TS [dcl.spec.concept]p7: A program shall not declare [...]
7201 // an explicit specialization (14.8.3) [...] of a concept definition.
7202 if (Specialization->getPrimaryTemplate()->isConcept()) {
7203 Diag(FD->getLocation(), diag::err_concept_specialized)
7204 << 0 /*function*/ << 1 /*explicitly specialized*/;
7205 Diag(Specialization->getLocation(), diag::note_previous_declaration);
7209 FunctionTemplateSpecializationInfo *SpecInfo
7210 = Specialization->getTemplateSpecializationInfo();
7211 assert(SpecInfo && "Function template specialization info missing?");
7213 // Note: do not overwrite location info if previous template
7214 // specialization kind was explicit.
7215 TemplateSpecializationKind TSK = SpecInfo->getTemplateSpecializationKind();
7216 if (TSK == TSK_Undeclared || TSK == TSK_ImplicitInstantiation) {
7217 Specialization->setLocation(FD->getLocation());
7218 // C++11 [dcl.constexpr]p1: An explicit specialization of a constexpr
7219 // function can differ from the template declaration with respect to
7220 // the constexpr specifier.
7221 Specialization->setConstexpr(FD->isConstexpr());
7224 // FIXME: Check if the prior specialization has a point of instantiation.
7225 // If so, we have run afoul of .
7227 // If this is a friend declaration, then we're not really declaring
7228 // an explicit specialization.
7229 bool isFriend = (FD->getFriendObjectKind() != Decl::FOK_None);
7231 // Check the scope of this explicit specialization.
7233 CheckTemplateSpecializationScope(*this,
7234 Specialization->getPrimaryTemplate(),
7235 Specialization, FD->getLocation(),
7239 // C++ [temp.expl.spec]p6:
7240 // If a template, a member template or the member of a class template is
7241 // explicitly specialized then that specialization shall be declared
7242 // before the first use of that specialization that would cause an implicit
7243 // instantiation to take place, in every translation unit in which such a
7244 // use occurs; no diagnostic is required.
7245 bool HasNoEffect = false;
7247 CheckSpecializationInstantiationRedecl(FD->getLocation(),
7248 TSK_ExplicitSpecialization,
7250 SpecInfo->getTemplateSpecializationKind(),
7251 SpecInfo->getPointOfInstantiation(),
7255 // Mark the prior declaration as an explicit specialization, so that later
7256 // clients know that this is an explicit specialization.
7258 // Since explicit specializations do not inherit '=delete' from their
7259 // primary function template - check if the 'specialization' that was
7260 // implicitly generated (during template argument deduction for partial
7261 // ordering) from the most specialized of all the function templates that
7262 // 'FD' could have been specializing, has a 'deleted' definition. If so,
7263 // first check that it was implicitly generated during template argument
7264 // deduction by making sure it wasn't referenced, and then reset the deleted
7265 // flag to not-deleted, so that we can inherit that information from 'FD'.
7266 if (Specialization->isDeleted() && !SpecInfo->isExplicitSpecialization() &&
7267 !Specialization->getCanonicalDecl()->isReferenced()) {
7269 Specialization->getCanonicalDecl() == Specialization &&
7270 "This must be the only existing declaration of this specialization");
7271 Specialization->setDeletedAsWritten(false);
7273 SpecInfo->setTemplateSpecializationKind(TSK_ExplicitSpecialization);
7274 MarkUnusedFileScopedDecl(Specialization);
7277 // Turn the given function declaration into a function template
7278 // specialization, with the template arguments from the previous
7280 // Take copies of (semantic and syntactic) template argument lists.
7281 const TemplateArgumentList* TemplArgs = new (Context)
7282 TemplateArgumentList(Specialization->getTemplateSpecializationArgs());
7283 FD->setFunctionTemplateSpecialization(
7284 Specialization->getPrimaryTemplate(), TemplArgs, /*InsertPos=*/nullptr,
7285 SpecInfo->getTemplateSpecializationKind(),
7286 ExplicitTemplateArgs ? &ConvertedTemplateArgs[Specialization] : nullptr);
7288 // A function template specialization inherits the target attributes
7289 // of its template. (We require the attributes explicitly in the
7290 // code to match, but a template may have implicit attributes by
7291 // virtue e.g. of being constexpr, and it passes these implicit
7292 // attributes on to its specializations.)
7294 inheritCUDATargetAttrs(FD, *Specialization->getPrimaryTemplate());
7296 // The "previous declaration" for this function template specialization is
7297 // the prior function template specialization.
7299 Previous.addDecl(Specialization);
7303 /// \brief Perform semantic analysis for the given non-template member
7306 /// This routine performs all of the semantic analysis required for an
7307 /// explicit member function specialization. On successful completion,
7308 /// the function declaration \p FD will become a member function
7311 /// \param Member the member declaration, which will be updated to become a
7314 /// \param Previous the set of declarations, one of which may be specialized
7315 /// by this function specialization; the set will be modified to contain the
7316 /// redeclared member.
7318 Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
7319 assert(!isa<TemplateDecl>(Member) && "Only for non-template members");
7321 // Try to find the member we are instantiating.
7322 NamedDecl *FoundInstantiation = nullptr;
7323 NamedDecl *Instantiation = nullptr;
7324 NamedDecl *InstantiatedFrom = nullptr;
7325 MemberSpecializationInfo *MSInfo = nullptr;
7327 if (Previous.empty()) {
7328 // Nowhere to look anyway.
7329 } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Member)) {
7330 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
7332 NamedDecl *D = (*I)->getUnderlyingDecl();
7333 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
7334 QualType Adjusted = Function->getType();
7335 if (!hasExplicitCallingConv(Adjusted))
7336 Adjusted = adjustCCAndNoReturn(Adjusted, Method->getType());
7337 if (Context.hasSameType(Adjusted, Method->getType())) {
7338 FoundInstantiation = *I;
7339 Instantiation = Method;
7340 InstantiatedFrom = Method->getInstantiatedFromMemberFunction();
7341 MSInfo = Method->getMemberSpecializationInfo();
7346 } else if (isa<VarDecl>(Member)) {
7348 if (Previous.isSingleResult() &&
7349 (PrevVar = dyn_cast<VarDecl>(Previous.getFoundDecl())))
7350 if (PrevVar->isStaticDataMember()) {
7351 FoundInstantiation = Previous.getRepresentativeDecl();
7352 Instantiation = PrevVar;
7353 InstantiatedFrom = PrevVar->getInstantiatedFromStaticDataMember();
7354 MSInfo = PrevVar->getMemberSpecializationInfo();
7356 } else if (isa<RecordDecl>(Member)) {
7357 CXXRecordDecl *PrevRecord;
7358 if (Previous.isSingleResult() &&
7359 (PrevRecord = dyn_cast<CXXRecordDecl>(Previous.getFoundDecl()))) {
7360 FoundInstantiation = Previous.getRepresentativeDecl();
7361 Instantiation = PrevRecord;
7362 InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass();
7363 MSInfo = PrevRecord->getMemberSpecializationInfo();
7365 } else if (isa<EnumDecl>(Member)) {
7367 if (Previous.isSingleResult() &&
7368 (PrevEnum = dyn_cast<EnumDecl>(Previous.getFoundDecl()))) {
7369 FoundInstantiation = Previous.getRepresentativeDecl();
7370 Instantiation = PrevEnum;
7371 InstantiatedFrom = PrevEnum->getInstantiatedFromMemberEnum();
7372 MSInfo = PrevEnum->getMemberSpecializationInfo();
7376 if (!Instantiation) {
7377 // There is no previous declaration that matches. Since member
7378 // specializations are always out-of-line, the caller will complain about
7379 // this mismatch later.
7383 // If this is a friend, just bail out here before we start turning
7384 // things into explicit specializations.
7385 if (Member->getFriendObjectKind() != Decl::FOK_None) {
7386 // Preserve instantiation information.
7387 if (InstantiatedFrom && isa<CXXMethodDecl>(Member)) {
7388 cast<CXXMethodDecl>(Member)->setInstantiationOfMemberFunction(
7389 cast<CXXMethodDecl>(InstantiatedFrom),
7390 cast<CXXMethodDecl>(Instantiation)->getTemplateSpecializationKind());
7391 } else if (InstantiatedFrom && isa<CXXRecordDecl>(Member)) {
7392 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
7393 cast<CXXRecordDecl>(InstantiatedFrom),
7394 cast<CXXRecordDecl>(Instantiation)->getTemplateSpecializationKind());
7398 Previous.addDecl(FoundInstantiation);
7402 // Make sure that this is a specialization of a member.
7403 if (!InstantiatedFrom) {
7404 Diag(Member->getLocation(), diag::err_spec_member_not_instantiated)
7406 Diag(Instantiation->getLocation(), diag::note_specialized_decl);
7410 // C++ [temp.expl.spec]p6:
7411 // If a template, a member template or the member of a class template is
7412 // explicitly specialized then that specialization shall be declared
7413 // before the first use of that specialization that would cause an implicit
7414 // instantiation to take place, in every translation unit in which such a
7415 // use occurs; no diagnostic is required.
7416 assert(MSInfo && "Member specialization info missing?");
7418 bool HasNoEffect = false;
7419 if (CheckSpecializationInstantiationRedecl(Member->getLocation(),
7420 TSK_ExplicitSpecialization,
7422 MSInfo->getTemplateSpecializationKind(),
7423 MSInfo->getPointOfInstantiation(),
7427 // Check the scope of this explicit specialization.
7428 if (CheckTemplateSpecializationScope(*this,
7430 Instantiation, Member->getLocation(),
7434 // Note that this is an explicit instantiation of a member.
7435 // the original declaration to note that it is an explicit specialization
7436 // (if it was previously an implicit instantiation). This latter step
7437 // makes bookkeeping easier.
7438 if (isa<FunctionDecl>(Member)) {
7439 FunctionDecl *InstantiationFunction = cast<FunctionDecl>(Instantiation);
7440 if (InstantiationFunction->getTemplateSpecializationKind() ==
7441 TSK_ImplicitInstantiation) {
7442 InstantiationFunction->setTemplateSpecializationKind(
7443 TSK_ExplicitSpecialization);
7444 InstantiationFunction->setLocation(Member->getLocation());
7445 // Explicit specializations of member functions of class templates do not
7446 // inherit '=delete' from the member function they are specializing.
7447 if (InstantiationFunction->isDeleted()) {
7448 assert(InstantiationFunction->getCanonicalDecl() ==
7449 InstantiationFunction);
7450 InstantiationFunction->setDeletedAsWritten(false);
7454 cast<FunctionDecl>(Member)->setInstantiationOfMemberFunction(
7455 cast<CXXMethodDecl>(InstantiatedFrom),
7456 TSK_ExplicitSpecialization);
7457 MarkUnusedFileScopedDecl(InstantiationFunction);
7458 } else if (isa<VarDecl>(Member)) {
7459 VarDecl *InstantiationVar = cast<VarDecl>(Instantiation);
7460 if (InstantiationVar->getTemplateSpecializationKind() ==
7461 TSK_ImplicitInstantiation) {
7462 InstantiationVar->setTemplateSpecializationKind(
7463 TSK_ExplicitSpecialization);
7464 InstantiationVar->setLocation(Member->getLocation());
7467 cast<VarDecl>(Member)->setInstantiationOfStaticDataMember(
7468 cast<VarDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
7469 MarkUnusedFileScopedDecl(InstantiationVar);
7470 } else if (isa<CXXRecordDecl>(Member)) {
7471 CXXRecordDecl *InstantiationClass = cast<CXXRecordDecl>(Instantiation);
7472 if (InstantiationClass->getTemplateSpecializationKind() ==
7473 TSK_ImplicitInstantiation) {
7474 InstantiationClass->setTemplateSpecializationKind(
7475 TSK_ExplicitSpecialization);
7476 InstantiationClass->setLocation(Member->getLocation());
7479 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
7480 cast<CXXRecordDecl>(InstantiatedFrom),
7481 TSK_ExplicitSpecialization);
7483 assert(isa<EnumDecl>(Member) && "Only member enums remain");
7484 EnumDecl *InstantiationEnum = cast<EnumDecl>(Instantiation);
7485 if (InstantiationEnum->getTemplateSpecializationKind() ==
7486 TSK_ImplicitInstantiation) {
7487 InstantiationEnum->setTemplateSpecializationKind(
7488 TSK_ExplicitSpecialization);
7489 InstantiationEnum->setLocation(Member->getLocation());
7492 cast<EnumDecl>(Member)->setInstantiationOfMemberEnum(
7493 cast<EnumDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
7496 // Save the caller the trouble of having to figure out which declaration
7497 // this specialization matches.
7499 Previous.addDecl(FoundInstantiation);
7503 /// \brief Check the scope of an explicit instantiation.
7505 /// \returns true if a serious error occurs, false otherwise.
7506 static bool CheckExplicitInstantiationScope(Sema &S, NamedDecl *D,
7507 SourceLocation InstLoc,
7508 bool WasQualifiedName) {
7509 DeclContext *OrigContext= D->getDeclContext()->getEnclosingNamespaceContext();
7510 DeclContext *CurContext = S.CurContext->getRedeclContext();
7512 if (CurContext->isRecord()) {
7513 S.Diag(InstLoc, diag::err_explicit_instantiation_in_class)
7518 // C++11 [temp.explicit]p3:
7519 // An explicit instantiation shall appear in an enclosing namespace of its
7520 // template. If the name declared in the explicit instantiation is an
7521 // unqualified name, the explicit instantiation shall appear in the
7522 // namespace where its template is declared or, if that namespace is inline
7523 // (7.3.1), any namespace from its enclosing namespace set.
7525 // This is DR275, which we do not retroactively apply to C++98/03.
7526 if (WasQualifiedName) {
7527 if (CurContext->Encloses(OrigContext))
7530 if (CurContext->InEnclosingNamespaceSetOf(OrigContext))
7534 if (NamespaceDecl *NS = dyn_cast<NamespaceDecl>(OrigContext)) {
7535 if (WasQualifiedName)
7537 S.getLangOpts().CPlusPlus11?
7538 diag::err_explicit_instantiation_out_of_scope :
7539 diag::warn_explicit_instantiation_out_of_scope_0x)
7543 S.getLangOpts().CPlusPlus11?
7544 diag::err_explicit_instantiation_unqualified_wrong_namespace :
7545 diag::warn_explicit_instantiation_unqualified_wrong_namespace_0x)
7549 S.getLangOpts().CPlusPlus11?
7550 diag::err_explicit_instantiation_must_be_global :
7551 diag::warn_explicit_instantiation_must_be_global_0x)
7553 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here);
7557 /// \brief Determine whether the given scope specifier has a template-id in it.
7558 static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec &SS) {
7562 // C++11 [temp.explicit]p3:
7563 // If the explicit instantiation is for a member function, a member class
7564 // or a static data member of a class template specialization, the name of
7565 // the class template specialization in the qualified-id for the member
7566 // name shall be a simple-template-id.
7568 // C++98 has the same restriction, just worded differently.
7569 for (NestedNameSpecifier *NNS = SS.getScopeRep(); NNS;
7570 NNS = NNS->getPrefix())
7571 if (const Type *T = NNS->getAsType())
7572 if (isa<TemplateSpecializationType>(T))
7578 /// Make a dllexport or dllimport attr on a class template specialization take
7580 static void dllExportImportClassTemplateSpecialization(
7581 Sema &S, ClassTemplateSpecializationDecl *Def) {
7582 auto *A = cast_or_null<InheritableAttr>(getDLLAttr(Def));
7583 assert(A && "dllExportImportClassTemplateSpecialization called "
7584 "on Def without dllexport or dllimport");
7586 // We reject explicit instantiations in class scope, so there should
7587 // never be any delayed exported classes to worry about.
7588 assert(S.DelayedDllExportClasses.empty() &&
7589 "delayed exports present at explicit instantiation");
7590 S.checkClassLevelDLLAttribute(Def);
7592 // Propagate attribute to base class templates.
7593 for (auto &B : Def->bases()) {
7594 if (auto *BT = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
7595 B.getType()->getAsCXXRecordDecl()))
7596 S.propagateDLLAttrToBaseClassTemplate(Def, A, BT, B.getLocStart());
7599 S.referenceDLLExportedClassMethods();
7602 // Explicit instantiation of a class template specialization
7604 Sema::ActOnExplicitInstantiation(Scope *S,
7605 SourceLocation ExternLoc,
7606 SourceLocation TemplateLoc,
7608 SourceLocation KWLoc,
7609 const CXXScopeSpec &SS,
7610 TemplateTy TemplateD,
7611 SourceLocation TemplateNameLoc,
7612 SourceLocation LAngleLoc,
7613 ASTTemplateArgsPtr TemplateArgsIn,
7614 SourceLocation RAngleLoc,
7615 AttributeList *Attr) {
7616 // Find the class template we're specializing
7617 TemplateName Name = TemplateD.get();
7618 TemplateDecl *TD = Name.getAsTemplateDecl();
7619 // Check that the specialization uses the same tag kind as the
7620 // original template.
7621 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
7622 assert(Kind != TTK_Enum &&
7623 "Invalid enum tag in class template explicit instantiation!");
7625 ClassTemplateDecl *ClassTemplate = dyn_cast<ClassTemplateDecl>(TD);
7627 if (!ClassTemplate) {
7628 NonTagKind NTK = getNonTagTypeDeclKind(TD, Kind);
7629 Diag(TemplateNameLoc, diag::err_tag_reference_non_tag) << TD << NTK << Kind;
7630 Diag(TD->getLocation(), diag::note_previous_use);
7634 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
7635 Kind, /*isDefinition*/false, KWLoc,
7636 ClassTemplate->getIdentifier())) {
7637 Diag(KWLoc, diag::err_use_with_wrong_tag)
7639 << FixItHint::CreateReplacement(KWLoc,
7640 ClassTemplate->getTemplatedDecl()->getKindName());
7641 Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
7642 diag::note_previous_use);
7643 Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
7646 // C++0x [temp.explicit]p2:
7647 // There are two forms of explicit instantiation: an explicit instantiation
7648 // definition and an explicit instantiation declaration. An explicit
7649 // instantiation declaration begins with the extern keyword. [...]
7650 TemplateSpecializationKind TSK = ExternLoc.isInvalid()
7651 ? TSK_ExplicitInstantiationDefinition
7652 : TSK_ExplicitInstantiationDeclaration;
7654 if (TSK == TSK_ExplicitInstantiationDeclaration) {
7655 // Check for dllexport class template instantiation declarations.
7656 for (AttributeList *A = Attr; A; A = A->getNext()) {
7657 if (A->getKind() == AttributeList::AT_DLLExport) {
7659 diag::warn_attribute_dllexport_explicit_instantiation_decl);
7660 Diag(A->getLoc(), diag::note_attribute);
7665 if (auto *A = ClassTemplate->getTemplatedDecl()->getAttr<DLLExportAttr>()) {
7667 diag::warn_attribute_dllexport_explicit_instantiation_decl);
7668 Diag(A->getLocation(), diag::note_attribute);
7672 // In MSVC mode, dllimported explicit instantiation definitions are treated as
7673 // instantiation declarations for most purposes.
7674 bool DLLImportExplicitInstantiationDef = false;
7675 if (TSK == TSK_ExplicitInstantiationDefinition &&
7676 Context.getTargetInfo().getCXXABI().isMicrosoft()) {
7677 // Check for dllimport class template instantiation definitions.
7679 ClassTemplate->getTemplatedDecl()->getAttr<DLLImportAttr>();
7680 for (AttributeList *A = Attr; A; A = A->getNext()) {
7681 if (A->getKind() == AttributeList::AT_DLLImport)
7683 if (A->getKind() == AttributeList::AT_DLLExport) {
7684 // dllexport trumps dllimport here.
7690 TSK = TSK_ExplicitInstantiationDeclaration;
7691 DLLImportExplicitInstantiationDef = true;
7695 // Translate the parser's template argument list in our AST format.
7696 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
7697 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
7699 // Check that the template argument list is well-formed for this
7701 SmallVector<TemplateArgument, 4> Converted;
7702 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
7703 TemplateArgs, false, Converted))
7706 // Find the class template specialization declaration that
7707 // corresponds to these arguments.
7708 void *InsertPos = nullptr;
7709 ClassTemplateSpecializationDecl *PrevDecl
7710 = ClassTemplate->findSpecialization(Converted, InsertPos);
7712 TemplateSpecializationKind PrevDecl_TSK
7713 = PrevDecl ? PrevDecl->getTemplateSpecializationKind() : TSK_Undeclared;
7715 // C++0x [temp.explicit]p2:
7716 // [...] An explicit instantiation shall appear in an enclosing
7717 // namespace of its template. [...]
7719 // This is C++ DR 275.
7720 if (CheckExplicitInstantiationScope(*this, ClassTemplate, TemplateNameLoc,
7724 ClassTemplateSpecializationDecl *Specialization = nullptr;
7726 bool HasNoEffect = false;
7728 if (CheckSpecializationInstantiationRedecl(TemplateNameLoc, TSK,
7729 PrevDecl, PrevDecl_TSK,
7730 PrevDecl->getPointOfInstantiation(),
7734 // Even though HasNoEffect == true means that this explicit instantiation
7735 // has no effect on semantics, we go on to put its syntax in the AST.
7737 if (PrevDecl_TSK == TSK_ImplicitInstantiation ||
7738 PrevDecl_TSK == TSK_Undeclared) {
7739 // Since the only prior class template specialization with these
7740 // arguments was referenced but not declared, reuse that
7741 // declaration node as our own, updating the source location
7742 // for the template name to reflect our new declaration.
7743 // (Other source locations will be updated later.)
7744 Specialization = PrevDecl;
7745 Specialization->setLocation(TemplateNameLoc);
7749 if (PrevDecl_TSK == TSK_ExplicitInstantiationDeclaration &&
7750 DLLImportExplicitInstantiationDef) {
7751 // The new specialization might add a dllimport attribute.
7752 HasNoEffect = false;
7756 if (!Specialization) {
7757 // Create a new class template specialization declaration node for
7758 // this explicit specialization.
7760 = ClassTemplateSpecializationDecl::Create(Context, Kind,
7761 ClassTemplate->getDeclContext(),
7762 KWLoc, TemplateNameLoc,
7766 SetNestedNameSpecifier(Specialization, SS);
7768 if (!HasNoEffect && !PrevDecl) {
7769 // Insert the new specialization.
7770 ClassTemplate->AddSpecialization(Specialization, InsertPos);
7774 // Build the fully-sugared type for this explicit instantiation as
7775 // the user wrote in the explicit instantiation itself. This means
7776 // that we'll pretty-print the type retrieved from the
7777 // specialization's declaration the way that the user actually wrote
7778 // the explicit instantiation, rather than formatting the name based
7779 // on the "canonical" representation used to store the template
7780 // arguments in the specialization.
7781 TypeSourceInfo *WrittenTy
7782 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
7784 Context.getTypeDeclType(Specialization));
7785 Specialization->setTypeAsWritten(WrittenTy);
7787 // Set source locations for keywords.
7788 Specialization->setExternLoc(ExternLoc);
7789 Specialization->setTemplateKeywordLoc(TemplateLoc);
7790 Specialization->setBraceRange(SourceRange());
7792 bool PreviouslyDLLExported = Specialization->hasAttr<DLLExportAttr>();
7794 ProcessDeclAttributeList(S, Specialization, Attr);
7796 // Add the explicit instantiation into its lexical context. However,
7797 // since explicit instantiations are never found by name lookup, we
7798 // just put it into the declaration context directly.
7799 Specialization->setLexicalDeclContext(CurContext);
7800 CurContext->addDecl(Specialization);
7802 // Syntax is now OK, so return if it has no other effect on semantics.
7804 // Set the template specialization kind.
7805 Specialization->setTemplateSpecializationKind(TSK);
7806 return Specialization;
7809 // C++ [temp.explicit]p3:
7810 // A definition of a class template or class member template
7811 // shall be in scope at the point of the explicit instantiation of
7812 // the class template or class member template.
7814 // This check comes when we actually try to perform the
7816 ClassTemplateSpecializationDecl *Def
7817 = cast_or_null<ClassTemplateSpecializationDecl>(
7818 Specialization->getDefinition());
7820 InstantiateClassTemplateSpecialization(TemplateNameLoc, Specialization, TSK);
7821 else if (TSK == TSK_ExplicitInstantiationDefinition) {
7822 MarkVTableUsed(TemplateNameLoc, Specialization, true);
7823 Specialization->setPointOfInstantiation(Def->getPointOfInstantiation());
7826 // Instantiate the members of this class template specialization.
7827 Def = cast_or_null<ClassTemplateSpecializationDecl>(
7828 Specialization->getDefinition());
7830 TemplateSpecializationKind Old_TSK = Def->getTemplateSpecializationKind();
7831 // Fix a TSK_ExplicitInstantiationDeclaration followed by a
7832 // TSK_ExplicitInstantiationDefinition
7833 if (Old_TSK == TSK_ExplicitInstantiationDeclaration &&
7834 (TSK == TSK_ExplicitInstantiationDefinition ||
7835 DLLImportExplicitInstantiationDef)) {
7836 // FIXME: Need to notify the ASTMutationListener that we did this.
7837 Def->setTemplateSpecializationKind(TSK);
7839 if (!getDLLAttr(Def) && getDLLAttr(Specialization) &&
7840 (Context.getTargetInfo().getCXXABI().isMicrosoft() ||
7841 Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment())) {
7842 // In the MS ABI, an explicit instantiation definition can add a dll
7843 // attribute to a template with a previous instantiation declaration.
7844 // MinGW doesn't allow this.
7845 auto *A = cast<InheritableAttr>(
7846 getDLLAttr(Specialization)->clone(getASTContext()));
7847 A->setInherited(true);
7849 dllExportImportClassTemplateSpecialization(*this, Def);
7853 // Fix a TSK_ImplicitInstantiation followed by a
7854 // TSK_ExplicitInstantiationDefinition
7855 bool NewlyDLLExported =
7856 !PreviouslyDLLExported && Specialization->hasAttr<DLLExportAttr>();
7857 if (Old_TSK == TSK_ImplicitInstantiation && NewlyDLLExported &&
7858 (Context.getTargetInfo().getCXXABI().isMicrosoft() ||
7859 Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment())) {
7860 // In the MS ABI, an explicit instantiation definition can add a dll
7861 // attribute to a template with a previous implicit instantiation.
7862 // MinGW doesn't allow this. We limit clang to only adding dllexport, to
7863 // avoid potentially strange codegen behavior. For example, if we extend
7864 // this conditional to dllimport, and we have a source file calling a
7865 // method on an implicitly instantiated template class instance and then
7866 // declaring a dllimport explicit instantiation definition for the same
7867 // template class, the codegen for the method call will not respect the
7868 // dllimport, while it will with cl. The Def will already have the DLL
7869 // attribute, since the Def and Specialization will be the same in the
7870 // case of Old_TSK == TSK_ImplicitInstantiation, and we already added the
7871 // attribute to the Specialization; we just need to make it take effect.
7872 assert(Def == Specialization &&
7873 "Def and Specialization should match for implicit instantiation");
7874 dllExportImportClassTemplateSpecialization(*this, Def);
7877 // Set the template specialization kind. Make sure it is set before
7878 // instantiating the members which will trigger ASTConsumer callbacks.
7879 Specialization->setTemplateSpecializationKind(TSK);
7880 InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK);
7883 // Set the template specialization kind.
7884 Specialization->setTemplateSpecializationKind(TSK);
7887 return Specialization;
7890 // Explicit instantiation of a member class of a class template.
7892 Sema::ActOnExplicitInstantiation(Scope *S,
7893 SourceLocation ExternLoc,
7894 SourceLocation TemplateLoc,
7896 SourceLocation KWLoc,
7898 IdentifierInfo *Name,
7899 SourceLocation NameLoc,
7900 AttributeList *Attr) {
7903 bool IsDependent = false;
7904 Decl *TagD = ActOnTag(S, TagSpec, Sema::TUK_Reference,
7905 KWLoc, SS, Name, NameLoc, Attr, AS_none,
7906 /*ModulePrivateLoc=*/SourceLocation(),
7907 MultiTemplateParamsArg(), Owned, IsDependent,
7908 SourceLocation(), false, TypeResult(),
7909 /*IsTypeSpecifier*/false);
7910 assert(!IsDependent && "explicit instantiation of dependent name not yet handled");
7915 TagDecl *Tag = cast<TagDecl>(TagD);
7916 assert(!Tag->isEnum() && "shouldn't see enumerations here");
7918 if (Tag->isInvalidDecl())
7921 CXXRecordDecl *Record = cast<CXXRecordDecl>(Tag);
7922 CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass();
7924 Diag(TemplateLoc, diag::err_explicit_instantiation_nontemplate_type)
7925 << Context.getTypeDeclType(Record);
7926 Diag(Record->getLocation(), diag::note_nontemplate_decl_here);
7930 // C++0x [temp.explicit]p2:
7931 // If the explicit instantiation is for a class or member class, the
7932 // elaborated-type-specifier in the declaration shall include a
7933 // simple-template-id.
7935 // C++98 has the same restriction, just worded differently.
7936 if (!ScopeSpecifierHasTemplateId(SS))
7937 Diag(TemplateLoc, diag::ext_explicit_instantiation_without_qualified_id)
7938 << Record << SS.getRange();
7940 // C++0x [temp.explicit]p2:
7941 // There are two forms of explicit instantiation: an explicit instantiation
7942 // definition and an explicit instantiation declaration. An explicit
7943 // instantiation declaration begins with the extern keyword. [...]
7944 TemplateSpecializationKind TSK
7945 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
7946 : TSK_ExplicitInstantiationDeclaration;
7948 // C++0x [temp.explicit]p2:
7949 // [...] An explicit instantiation shall appear in an enclosing
7950 // namespace of its template. [...]
7952 // This is C++ DR 275.
7953 CheckExplicitInstantiationScope(*this, Record, NameLoc, true);
7955 // Verify that it is okay to explicitly instantiate here.
7956 CXXRecordDecl *PrevDecl
7957 = cast_or_null<CXXRecordDecl>(Record->getPreviousDecl());
7958 if (!PrevDecl && Record->getDefinition())
7961 MemberSpecializationInfo *MSInfo = PrevDecl->getMemberSpecializationInfo();
7962 bool HasNoEffect = false;
7963 assert(MSInfo && "No member specialization information?");
7964 if (CheckSpecializationInstantiationRedecl(TemplateLoc, TSK,
7966 MSInfo->getTemplateSpecializationKind(),
7967 MSInfo->getPointOfInstantiation(),
7974 CXXRecordDecl *RecordDef
7975 = cast_or_null<CXXRecordDecl>(Record->getDefinition());
7977 // C++ [temp.explicit]p3:
7978 // A definition of a member class of a class template shall be in scope
7979 // at the point of an explicit instantiation of the member class.
7981 = cast_or_null<CXXRecordDecl>(Pattern->getDefinition());
7983 Diag(TemplateLoc, diag::err_explicit_instantiation_undefined_member)
7984 << 0 << Record->getDeclName() << Record->getDeclContext();
7985 Diag(Pattern->getLocation(), diag::note_forward_declaration)
7989 if (InstantiateClass(NameLoc, Record, Def,
7990 getTemplateInstantiationArgs(Record),
7994 RecordDef = cast_or_null<CXXRecordDecl>(Record->getDefinition());
8000 // Instantiate all of the members of the class.
8001 InstantiateClassMembers(NameLoc, RecordDef,
8002 getTemplateInstantiationArgs(Record), TSK);
8004 if (TSK == TSK_ExplicitInstantiationDefinition)
8005 MarkVTableUsed(NameLoc, RecordDef, true);
8007 // FIXME: We don't have any representation for explicit instantiations of
8008 // member classes. Such a representation is not needed for compilation, but it
8009 // should be available for clients that want to see all of the declarations in
8014 DeclResult Sema::ActOnExplicitInstantiation(Scope *S,
8015 SourceLocation ExternLoc,
8016 SourceLocation TemplateLoc,
8018 // Explicit instantiations always require a name.
8019 // TODO: check if/when DNInfo should replace Name.
8020 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
8021 DeclarationName Name = NameInfo.getName();
8023 if (!D.isInvalidType())
8024 Diag(D.getDeclSpec().getLocStart(),
8025 diag::err_explicit_instantiation_requires_name)
8026 << D.getDeclSpec().getSourceRange()
8027 << D.getSourceRange();
8032 // The scope passed in may not be a decl scope. Zip up the scope tree until
8033 // we find one that is.
8034 while ((S->getFlags() & Scope::DeclScope) == 0 ||
8035 (S->getFlags() & Scope::TemplateParamScope) != 0)
8038 // Determine the type of the declaration.
8039 TypeSourceInfo *T = GetTypeForDeclarator(D, S);
8040 QualType R = T->getType();
8045 // A storage-class-specifier shall not be specified in [...] an explicit
8046 // instantiation (14.7.2) directive.
8047 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
8048 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_of_typedef)
8051 } else if (D.getDeclSpec().getStorageClassSpec()
8052 != DeclSpec::SCS_unspecified) {
8053 // Complain about then remove the storage class specifier.
8054 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_storage_class)
8055 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
8057 D.getMutableDeclSpec().ClearStorageClassSpecs();
8060 // C++0x [temp.explicit]p1:
8061 // [...] An explicit instantiation of a function template shall not use the
8062 // inline or constexpr specifiers.
8063 // Presumably, this also applies to member functions of class templates as
8065 if (D.getDeclSpec().isInlineSpecified())
8066 Diag(D.getDeclSpec().getInlineSpecLoc(),
8067 getLangOpts().CPlusPlus11 ?
8068 diag::err_explicit_instantiation_inline :
8069 diag::warn_explicit_instantiation_inline_0x)
8070 << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
8071 if (D.getDeclSpec().isConstexprSpecified() && R->isFunctionType())
8072 // FIXME: Add a fix-it to remove the 'constexpr' and add a 'const' if one is
8073 // not already specified.
8074 Diag(D.getDeclSpec().getConstexprSpecLoc(),
8075 diag::err_explicit_instantiation_constexpr);
8077 // C++ Concepts TS [dcl.spec.concept]p1: The concept specifier shall be
8078 // applied only to the definition of a function template or variable template,
8079 // declared in namespace scope.
8080 if (D.getDeclSpec().isConceptSpecified()) {
8081 Diag(D.getDeclSpec().getConceptSpecLoc(),
8082 diag::err_concept_specified_specialization) << 0;
8086 // C++0x [temp.explicit]p2:
8087 // There are two forms of explicit instantiation: an explicit instantiation
8088 // definition and an explicit instantiation declaration. An explicit
8089 // instantiation declaration begins with the extern keyword. [...]
8090 TemplateSpecializationKind TSK
8091 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
8092 : TSK_ExplicitInstantiationDeclaration;
8094 LookupResult Previous(*this, NameInfo, LookupOrdinaryName);
8095 LookupParsedName(Previous, S, &D.getCXXScopeSpec());
8097 if (!R->isFunctionType()) {
8098 // C++ [temp.explicit]p1:
8099 // A [...] static data member of a class template can be explicitly
8100 // instantiated from the member definition associated with its class
8102 // C++1y [temp.explicit]p1:
8103 // A [...] variable [...] template specialization can be explicitly
8104 // instantiated from its template.
8105 if (Previous.isAmbiguous())
8108 VarDecl *Prev = Previous.getAsSingle<VarDecl>();
8109 VarTemplateDecl *PrevTemplate = Previous.getAsSingle<VarTemplateDecl>();
8111 if (!PrevTemplate) {
8112 if (!Prev || !Prev->isStaticDataMember()) {
8113 // We expect to see a data data member here.
8114 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_not_known)
8116 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
8118 Diag((*P)->getLocation(), diag::note_explicit_instantiation_here);
8122 if (!Prev->getInstantiatedFromStaticDataMember()) {
8123 // FIXME: Check for explicit specialization?
8124 Diag(D.getIdentifierLoc(),
8125 diag::err_explicit_instantiation_data_member_not_instantiated)
8127 Diag(Prev->getLocation(), diag::note_explicit_instantiation_here);
8128 // FIXME: Can we provide a note showing where this was declared?
8132 // Explicitly instantiate a variable template.
8134 // C++1y [dcl.spec.auto]p6:
8135 // ... A program that uses auto or decltype(auto) in a context not
8136 // explicitly allowed in this section is ill-formed.
8138 // This includes auto-typed variable template instantiations.
8139 if (R->isUndeducedType()) {
8140 Diag(T->getTypeLoc().getLocStart(),
8141 diag::err_auto_not_allowed_var_inst);
8145 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId) {
8146 // C++1y [temp.explicit]p3:
8147 // If the explicit instantiation is for a variable, the unqualified-id
8148 // in the declaration shall be a template-id.
8149 Diag(D.getIdentifierLoc(),
8150 diag::err_explicit_instantiation_without_template_id)
8152 Diag(PrevTemplate->getLocation(),
8153 diag::note_explicit_instantiation_here);
8157 // C++ Concepts TS [dcl.spec.concept]p7: A program shall not declare an
8158 // explicit instantiation (14.8.2) [...] of a concept definition.
8159 if (PrevTemplate->isConcept()) {
8160 Diag(D.getIdentifierLoc(), diag::err_concept_specialized)
8161 << 1 /*variable*/ << 0 /*explicitly instantiated*/;
8162 Diag(PrevTemplate->getLocation(), diag::note_previous_declaration);
8166 // Translate the parser's template argument list into our AST format.
8167 TemplateArgumentListInfo TemplateArgs =
8168 makeTemplateArgumentListInfo(*this, *D.getName().TemplateId);
8170 DeclResult Res = CheckVarTemplateId(PrevTemplate, TemplateLoc,
8171 D.getIdentifierLoc(), TemplateArgs);
8172 if (Res.isInvalid())
8175 // Ignore access control bits, we don't need them for redeclaration
8177 Prev = cast<VarDecl>(Res.get());
8180 // C++0x [temp.explicit]p2:
8181 // If the explicit instantiation is for a member function, a member class
8182 // or a static data member of a class template specialization, the name of
8183 // the class template specialization in the qualified-id for the member
8184 // name shall be a simple-template-id.
8186 // C++98 has the same restriction, just worded differently.
8188 // This does not apply to variable template specializations, where the
8189 // template-id is in the unqualified-id instead.
8190 if (!ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()) && !PrevTemplate)
8191 Diag(D.getIdentifierLoc(),
8192 diag::ext_explicit_instantiation_without_qualified_id)
8193 << Prev << D.getCXXScopeSpec().getRange();
8195 // Check the scope of this explicit instantiation.
8196 CheckExplicitInstantiationScope(*this, Prev, D.getIdentifierLoc(), true);
8198 // Verify that it is okay to explicitly instantiate here.
8199 TemplateSpecializationKind PrevTSK = Prev->getTemplateSpecializationKind();
8200 SourceLocation POI = Prev->getPointOfInstantiation();
8201 bool HasNoEffect = false;
8202 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, Prev,
8203 PrevTSK, POI, HasNoEffect))
8207 // Instantiate static data member or variable template.
8209 Prev->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
8211 // Merge attributes.
8212 if (AttributeList *Attr = D.getDeclSpec().getAttributes().getList())
8213 ProcessDeclAttributeList(S, Prev, Attr);
8215 if (TSK == TSK_ExplicitInstantiationDefinition)
8216 InstantiateVariableDefinition(D.getIdentifierLoc(), Prev);
8219 // Check the new variable specialization against the parsed input.
8220 if (PrevTemplate && Prev && !Context.hasSameType(Prev->getType(), R)) {
8221 Diag(T->getTypeLoc().getLocStart(),
8222 diag::err_invalid_var_template_spec_type)
8223 << 0 << PrevTemplate << R << Prev->getType();
8224 Diag(PrevTemplate->getLocation(), diag::note_template_declared_here)
8225 << 2 << PrevTemplate->getDeclName();
8229 // FIXME: Create an ExplicitInstantiation node?
8230 return (Decl*) nullptr;
8233 // If the declarator is a template-id, translate the parser's template
8234 // argument list into our AST format.
8235 bool HasExplicitTemplateArgs = false;
8236 TemplateArgumentListInfo TemplateArgs;
8237 if (D.getName().getKind() == UnqualifiedId::IK_TemplateId) {
8238 TemplateArgs = makeTemplateArgumentListInfo(*this, *D.getName().TemplateId);
8239 HasExplicitTemplateArgs = true;
8242 // C++ [temp.explicit]p1:
8243 // A [...] function [...] can be explicitly instantiated from its template.
8244 // A member function [...] of a class template can be explicitly
8245 // instantiated from the member definition associated with its class
8247 UnresolvedSet<8> Matches;
8248 AttributeList *Attr = D.getDeclSpec().getAttributes().getList();
8249 TemplateSpecCandidateSet FailedCandidates(D.getIdentifierLoc());
8250 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
8252 NamedDecl *Prev = *P;
8253 if (!HasExplicitTemplateArgs) {
8254 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Prev)) {
8255 QualType Adjusted = adjustCCAndNoReturn(R, Method->getType(),
8256 /*AdjustExceptionSpec*/true);
8257 if (Context.hasSameUnqualifiedType(Method->getType(), Adjusted)) {
8260 Matches.addDecl(Method, P.getAccess());
8261 if (Method->getTemplateSpecializationKind() == TSK_Undeclared)
8267 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Prev);
8271 TemplateDeductionInfo Info(FailedCandidates.getLocation());
8272 FunctionDecl *Specialization = nullptr;
8273 if (TemplateDeductionResult TDK
8274 = DeduceTemplateArguments(FunTmpl,
8275 (HasExplicitTemplateArgs ? &TemplateArgs
8277 R, Specialization, Info)) {
8278 // Keep track of almost-matches.
8279 FailedCandidates.addCandidate()
8280 .set(P.getPair(), FunTmpl->getTemplatedDecl(),
8281 MakeDeductionFailureInfo(Context, TDK, Info));
8286 // Target attributes are part of the cuda function signature, so
8287 // the cuda target of the instantiated function must match that of its
8288 // template. Given that C++ template deduction does not take
8289 // target attributes into account, we reject candidates here that
8290 // have a different target.
8291 if (LangOpts.CUDA &&
8292 IdentifyCUDATarget(Specialization,
8293 /* IgnoreImplicitHDAttributes = */ true) !=
8294 IdentifyCUDATarget(Attr)) {
8295 FailedCandidates.addCandidate().set(
8296 P.getPair(), FunTmpl->getTemplatedDecl(),
8297 MakeDeductionFailureInfo(Context, TDK_CUDATargetMismatch, Info));
8301 Matches.addDecl(Specialization, P.getAccess());
8304 // Find the most specialized function template specialization.
8305 UnresolvedSetIterator Result = getMostSpecialized(
8306 Matches.begin(), Matches.end(), FailedCandidates,
8307 D.getIdentifierLoc(),
8308 PDiag(diag::err_explicit_instantiation_not_known) << Name,
8309 PDiag(diag::err_explicit_instantiation_ambiguous) << Name,
8310 PDiag(diag::note_explicit_instantiation_candidate));
8312 if (Result == Matches.end())
8315 // Ignore access control bits, we don't need them for redeclaration checking.
8316 FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
8318 // C++11 [except.spec]p4
8319 // In an explicit instantiation an exception-specification may be specified,
8320 // but is not required.
8321 // If an exception-specification is specified in an explicit instantiation
8322 // directive, it shall be compatible with the exception-specifications of
8323 // other declarations of that function.
8324 if (auto *FPT = R->getAs<FunctionProtoType>())
8325 if (FPT->hasExceptionSpec()) {
8327 diag::err_mismatched_exception_spec_explicit_instantiation;
8328 if (getLangOpts().MicrosoftExt)
8329 DiagID = diag::ext_mismatched_exception_spec_explicit_instantiation;
8330 bool Result = CheckEquivalentExceptionSpec(
8331 PDiag(DiagID) << Specialization->getType(),
8332 PDiag(diag::note_explicit_instantiation_here),
8333 Specialization->getType()->getAs<FunctionProtoType>(),
8334 Specialization->getLocation(), FPT, D.getLocStart());
8335 // In Microsoft mode, mismatching exception specifications just cause a
8337 if (!getLangOpts().MicrosoftExt && Result)
8341 if (Specialization->getTemplateSpecializationKind() == TSK_Undeclared) {
8342 Diag(D.getIdentifierLoc(),
8343 diag::err_explicit_instantiation_member_function_not_instantiated)
8345 << (Specialization->getTemplateSpecializationKind() ==
8346 TSK_ExplicitSpecialization);
8347 Diag(Specialization->getLocation(), diag::note_explicit_instantiation_here);
8351 FunctionDecl *PrevDecl = Specialization->getPreviousDecl();
8352 if (!PrevDecl && Specialization->isThisDeclarationADefinition())
8353 PrevDecl = Specialization;
8356 bool HasNoEffect = false;
8357 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK,
8359 PrevDecl->getTemplateSpecializationKind(),
8360 PrevDecl->getPointOfInstantiation(),
8364 // FIXME: We may still want to build some representation of this
8365 // explicit specialization.
8367 return (Decl*) nullptr;
8370 Specialization->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
8372 ProcessDeclAttributeList(S, Specialization, Attr);
8374 if (Specialization->isDefined()) {
8375 // Let the ASTConsumer know that this function has been explicitly
8376 // instantiated now, and its linkage might have changed.
8377 Consumer.HandleTopLevelDecl(DeclGroupRef(Specialization));
8378 } else if (TSK == TSK_ExplicitInstantiationDefinition)
8379 InstantiateFunctionDefinition(D.getIdentifierLoc(), Specialization);
8381 // C++0x [temp.explicit]p2:
8382 // If the explicit instantiation is for a member function, a member class
8383 // or a static data member of a class template specialization, the name of
8384 // the class template specialization in the qualified-id for the member
8385 // name shall be a simple-template-id.
8387 // C++98 has the same restriction, just worded differently.
8388 FunctionTemplateDecl *FunTmpl = Specialization->getPrimaryTemplate();
8389 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId && !FunTmpl &&
8390 D.getCXXScopeSpec().isSet() &&
8391 !ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()))
8392 Diag(D.getIdentifierLoc(),
8393 diag::ext_explicit_instantiation_without_qualified_id)
8394 << Specialization << D.getCXXScopeSpec().getRange();
8396 // C++ Concepts TS [dcl.spec.concept]p7: A program shall not declare an
8397 // explicit instantiation (14.8.2) [...] of a concept definition.
8398 if (FunTmpl && FunTmpl->isConcept() &&
8399 !D.getDeclSpec().isConceptSpecified()) {
8400 Diag(D.getIdentifierLoc(), diag::err_concept_specialized)
8401 << 0 /*function*/ << 0 /*explicitly instantiated*/;
8402 Diag(FunTmpl->getLocation(), diag::note_previous_declaration);
8406 CheckExplicitInstantiationScope(*this,
8407 FunTmpl? (NamedDecl *)FunTmpl
8408 : Specialization->getInstantiatedFromMemberFunction(),
8409 D.getIdentifierLoc(),
8410 D.getCXXScopeSpec().isSet());
8412 // FIXME: Create some kind of ExplicitInstantiationDecl here.
8413 return (Decl*) nullptr;
8417 Sema::ActOnDependentTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
8418 const CXXScopeSpec &SS, IdentifierInfo *Name,
8419 SourceLocation TagLoc, SourceLocation NameLoc) {
8420 // This has to hold, because SS is expected to be defined.
8421 assert(Name && "Expected a name in a dependent tag");
8423 NestedNameSpecifier *NNS = SS.getScopeRep();
8427 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
8429 if (TUK == TUK_Declaration || TUK == TUK_Definition) {
8430 Diag(NameLoc, diag::err_dependent_tag_decl)
8431 << (TUK == TUK_Definition) << Kind << SS.getRange();
8435 // Create the resulting type.
8436 ElaboratedTypeKeyword Kwd = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
8437 QualType Result = Context.getDependentNameType(Kwd, NNS, Name);
8439 // Create type-source location information for this type.
8441 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(Result);
8442 TL.setElaboratedKeywordLoc(TagLoc);
8443 TL.setQualifierLoc(SS.getWithLocInContext(Context));
8444 TL.setNameLoc(NameLoc);
8445 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
8449 Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc,
8450 const CXXScopeSpec &SS, const IdentifierInfo &II,
8451 SourceLocation IdLoc) {
8455 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
8457 getLangOpts().CPlusPlus11 ?
8458 diag::warn_cxx98_compat_typename_outside_of_template :
8459 diag::ext_typename_outside_of_template)
8460 << FixItHint::CreateRemoval(TypenameLoc);
8462 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
8463 QualType T = CheckTypenameType(TypenameLoc.isValid()? ETK_Typename : ETK_None,
8464 TypenameLoc, QualifierLoc, II, IdLoc);
8468 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
8469 if (isa<DependentNameType>(T)) {
8470 DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
8471 TL.setElaboratedKeywordLoc(TypenameLoc);
8472 TL.setQualifierLoc(QualifierLoc);
8473 TL.setNameLoc(IdLoc);
8475 ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>();
8476 TL.setElaboratedKeywordLoc(TypenameLoc);
8477 TL.setQualifierLoc(QualifierLoc);
8478 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
8481 return CreateParsedType(T, TSI);
8485 Sema::ActOnTypenameType(Scope *S,
8486 SourceLocation TypenameLoc,
8487 const CXXScopeSpec &SS,
8488 SourceLocation TemplateKWLoc,
8489 TemplateTy TemplateIn,
8490 SourceLocation TemplateNameLoc,
8491 SourceLocation LAngleLoc,
8492 ASTTemplateArgsPtr TemplateArgsIn,
8493 SourceLocation RAngleLoc) {
8494 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
8496 getLangOpts().CPlusPlus11 ?
8497 diag::warn_cxx98_compat_typename_outside_of_template :
8498 diag::ext_typename_outside_of_template)
8499 << FixItHint::CreateRemoval(TypenameLoc);
8501 // Translate the parser's template argument list in our AST format.
8502 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
8503 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
8505 TemplateName Template = TemplateIn.get();
8506 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
8507 // Construct a dependent template specialization type.
8508 assert(DTN && "dependent template has non-dependent name?");
8509 assert(DTN->getQualifier() == SS.getScopeRep());
8510 QualType T = Context.getDependentTemplateSpecializationType(ETK_Typename,
8511 DTN->getQualifier(),
8512 DTN->getIdentifier(),
8515 // Create source-location information for this type.
8516 TypeLocBuilder Builder;
8517 DependentTemplateSpecializationTypeLoc SpecTL
8518 = Builder.push<DependentTemplateSpecializationTypeLoc>(T);
8519 SpecTL.setElaboratedKeywordLoc(TypenameLoc);
8520 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
8521 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
8522 SpecTL.setTemplateNameLoc(TemplateNameLoc);
8523 SpecTL.setLAngleLoc(LAngleLoc);
8524 SpecTL.setRAngleLoc(RAngleLoc);
8525 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
8526 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
8527 return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
8530 QualType T = CheckTemplateIdType(Template, TemplateNameLoc, TemplateArgs);
8534 // Provide source-location information for the template specialization type.
8535 TypeLocBuilder Builder;
8536 TemplateSpecializationTypeLoc SpecTL
8537 = Builder.push<TemplateSpecializationTypeLoc>(T);
8538 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
8539 SpecTL.setTemplateNameLoc(TemplateNameLoc);
8540 SpecTL.setLAngleLoc(LAngleLoc);
8541 SpecTL.setRAngleLoc(RAngleLoc);
8542 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
8543 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
8545 T = Context.getElaboratedType(ETK_Typename, SS.getScopeRep(), T);
8546 ElaboratedTypeLoc TL = Builder.push<ElaboratedTypeLoc>(T);
8547 TL.setElaboratedKeywordLoc(TypenameLoc);
8548 TL.setQualifierLoc(SS.getWithLocInContext(Context));
8550 TypeSourceInfo *TSI = Builder.getTypeSourceInfo(Context, T);
8551 return CreateParsedType(T, TSI);
8555 /// Determine whether this failed name lookup should be treated as being
8556 /// disabled by a usage of std::enable_if.
8557 static bool isEnableIf(NestedNameSpecifierLoc NNS, const IdentifierInfo &II,
8558 SourceRange &CondRange) {
8559 // We must be looking for a ::type...
8560 if (!II.isStr("type"))
8563 // ... within an explicitly-written template specialization...
8564 if (!NNS || !NNS.getNestedNameSpecifier()->getAsType())
8566 TypeLoc EnableIfTy = NNS.getTypeLoc();
8567 TemplateSpecializationTypeLoc EnableIfTSTLoc =
8568 EnableIfTy.getAs<TemplateSpecializationTypeLoc>();
8569 if (!EnableIfTSTLoc || EnableIfTSTLoc.getNumArgs() == 0)
8571 const TemplateSpecializationType *EnableIfTST =
8572 cast<TemplateSpecializationType>(EnableIfTSTLoc.getTypePtr());
8574 // ... which names a complete class template declaration...
8575 const TemplateDecl *EnableIfDecl =
8576 EnableIfTST->getTemplateName().getAsTemplateDecl();
8577 if (!EnableIfDecl || EnableIfTST->isIncompleteType())
8580 // ... called "enable_if".
8581 const IdentifierInfo *EnableIfII =
8582 EnableIfDecl->getDeclName().getAsIdentifierInfo();
8583 if (!EnableIfII || !EnableIfII->isStr("enable_if"))
8586 // Assume the first template argument is the condition.
8587 CondRange = EnableIfTSTLoc.getArgLoc(0).getSourceRange();
8591 /// \brief Build the type that describes a C++ typename specifier,
8592 /// e.g., "typename T::type".
8594 Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword,
8595 SourceLocation KeywordLoc,
8596 NestedNameSpecifierLoc QualifierLoc,
8597 const IdentifierInfo &II,
8598 SourceLocation IILoc) {
8600 SS.Adopt(QualifierLoc);
8602 DeclContext *Ctx = computeDeclContext(SS);
8604 // If the nested-name-specifier is dependent and couldn't be
8605 // resolved to a type, build a typename type.
8606 assert(QualifierLoc.getNestedNameSpecifier()->isDependent());
8607 return Context.getDependentNameType(Keyword,
8608 QualifierLoc.getNestedNameSpecifier(),
8612 // If the nested-name-specifier refers to the current instantiation,
8613 // the "typename" keyword itself is superfluous. In C++03, the
8614 // program is actually ill-formed. However, DR 382 (in C++0x CD1)
8615 // allows such extraneous "typename" keywords, and we retroactively
8616 // apply this DR to C++03 code with only a warning. In any case we continue.
8618 if (RequireCompleteDeclContext(SS, Ctx))
8621 DeclarationName Name(&II);
8622 LookupResult Result(*this, Name, IILoc, LookupOrdinaryName);
8623 LookupQualifiedName(Result, Ctx, SS);
8624 unsigned DiagID = 0;
8625 Decl *Referenced = nullptr;
8626 switch (Result.getResultKind()) {
8627 case LookupResult::NotFound: {
8628 // If we're looking up 'type' within a template named 'enable_if', produce
8629 // a more specific diagnostic.
8630 SourceRange CondRange;
8631 if (isEnableIf(QualifierLoc, II, CondRange)) {
8632 Diag(CondRange.getBegin(), diag::err_typename_nested_not_found_enable_if)
8633 << Ctx << CondRange;
8637 DiagID = diag::err_typename_nested_not_found;
8641 case LookupResult::FoundUnresolvedValue: {
8642 // We found a using declaration that is a value. Most likely, the using
8643 // declaration itself is meant to have the 'typename' keyword.
8644 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
8646 Diag(IILoc, diag::err_typename_refers_to_using_value_decl)
8647 << Name << Ctx << FullRange;
8648 if (UnresolvedUsingValueDecl *Using
8649 = dyn_cast<UnresolvedUsingValueDecl>(Result.getRepresentativeDecl())){
8650 SourceLocation Loc = Using->getQualifierLoc().getBeginLoc();
8651 Diag(Loc, diag::note_using_value_decl_missing_typename)
8652 << FixItHint::CreateInsertion(Loc, "typename ");
8655 // Fall through to create a dependent typename type, from which we can recover
8658 case LookupResult::NotFoundInCurrentInstantiation:
8659 // Okay, it's a member of an unknown instantiation.
8660 return Context.getDependentNameType(Keyword,
8661 QualifierLoc.getNestedNameSpecifier(),
8664 case LookupResult::Found:
8665 if (TypeDecl *Type = dyn_cast<TypeDecl>(Result.getFoundDecl())) {
8666 // We found a type. Build an ElaboratedType, since the
8667 // typename-specifier was just sugar.
8668 MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
8669 return Context.getElaboratedType(ETK_Typename,
8670 QualifierLoc.getNestedNameSpecifier(),
8671 Context.getTypeDeclType(Type));
8674 DiagID = diag::err_typename_nested_not_type;
8675 Referenced = Result.getFoundDecl();
8678 case LookupResult::FoundOverloaded:
8679 DiagID = diag::err_typename_nested_not_type;
8680 Referenced = *Result.begin();
8683 case LookupResult::Ambiguous:
8687 // If we get here, it's because name lookup did not find a
8688 // type. Emit an appropriate diagnostic and return an error.
8689 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
8691 Diag(IILoc, DiagID) << FullRange << Name << Ctx;
8693 Diag(Referenced->getLocation(), diag::note_typename_refers_here)
8699 // See Sema::RebuildTypeInCurrentInstantiation
8700 class CurrentInstantiationRebuilder
8701 : public TreeTransform<CurrentInstantiationRebuilder> {
8703 DeclarationName Entity;
8706 typedef TreeTransform<CurrentInstantiationRebuilder> inherited;
8708 CurrentInstantiationRebuilder(Sema &SemaRef,
8710 DeclarationName Entity)
8711 : TreeTransform<CurrentInstantiationRebuilder>(SemaRef),
8712 Loc(Loc), Entity(Entity) { }
8714 /// \brief Determine whether the given type \p T has already been
8717 /// For the purposes of type reconstruction, a type has already been
8718 /// transformed if it is NULL or if it is not dependent.
8719 bool AlreadyTransformed(QualType T) {
8720 return T.isNull() || !T->isDependentType();
8723 /// \brief Returns the location of the entity whose type is being
8725 SourceLocation getBaseLocation() { return Loc; }
8727 /// \brief Returns the name of the entity whose type is being rebuilt.
8728 DeclarationName getBaseEntity() { return Entity; }
8730 /// \brief Sets the "base" location and entity when that
8731 /// information is known based on another transformation.
8732 void setBase(SourceLocation Loc, DeclarationName Entity) {
8734 this->Entity = Entity;
8737 ExprResult TransformLambdaExpr(LambdaExpr *E) {
8738 // Lambdas never need to be transformed.
8742 } // end anonymous namespace
8744 /// \brief Rebuilds a type within the context of the current instantiation.
8746 /// The type \p T is part of the type of an out-of-line member definition of
8747 /// a class template (or class template partial specialization) that was parsed
8748 /// and constructed before we entered the scope of the class template (or
8749 /// partial specialization thereof). This routine will rebuild that type now
8750 /// that we have entered the declarator's scope, which may produce different
8751 /// canonical types, e.g.,
8754 /// template<typename T>
8756 /// typedef T* pointer;
8760 /// template<typename T>
8761 /// typename X<T>::pointer X<T>::data() { ... }
8764 /// Here, the type "typename X<T>::pointer" will be created as a DependentNameType,
8765 /// since we do not know that we can look into X<T> when we parsed the type.
8766 /// This function will rebuild the type, performing the lookup of "pointer"
8767 /// in X<T> and returning an ElaboratedType whose canonical type is the same
8768 /// as the canonical type of T*, allowing the return types of the out-of-line
8769 /// definition and the declaration to match.
8770 TypeSourceInfo *Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo *T,
8772 DeclarationName Name) {
8773 if (!T || !T->getType()->isDependentType())
8776 CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name);
8777 return Rebuilder.TransformType(T);
8780 ExprResult Sema::RebuildExprInCurrentInstantiation(Expr *E) {
8781 CurrentInstantiationRebuilder Rebuilder(*this, E->getExprLoc(),
8783 return Rebuilder.TransformExpr(E);
8786 bool Sema::RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS) {
8790 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
8791 CurrentInstantiationRebuilder Rebuilder(*this, SS.getRange().getBegin(),
8793 NestedNameSpecifierLoc Rebuilt
8794 = Rebuilder.TransformNestedNameSpecifierLoc(QualifierLoc);
8802 /// \brief Rebuild the template parameters now that we know we're in a current
8804 bool Sema::RebuildTemplateParamsInCurrentInstantiation(
8805 TemplateParameterList *Params) {
8806 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
8807 Decl *Param = Params->getParam(I);
8809 // There is nothing to rebuild in a type parameter.
8810 if (isa<TemplateTypeParmDecl>(Param))
8813 // Rebuild the template parameter list of a template template parameter.
8814 if (TemplateTemplateParmDecl *TTP
8815 = dyn_cast<TemplateTemplateParmDecl>(Param)) {
8816 if (RebuildTemplateParamsInCurrentInstantiation(
8817 TTP->getTemplateParameters()))
8823 // Rebuild the type of a non-type template parameter.
8824 NonTypeTemplateParmDecl *NTTP = cast<NonTypeTemplateParmDecl>(Param);
8825 TypeSourceInfo *NewTSI
8826 = RebuildTypeInCurrentInstantiation(NTTP->getTypeSourceInfo(),
8827 NTTP->getLocation(),
8828 NTTP->getDeclName());
8832 if (NewTSI != NTTP->getTypeSourceInfo()) {
8833 NTTP->setTypeSourceInfo(NewTSI);
8834 NTTP->setType(NewTSI->getType());
8841 /// \brief Produces a formatted string that describes the binding of
8842 /// template parameters to template arguments.
8844 Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
8845 const TemplateArgumentList &Args) {
8846 return getTemplateArgumentBindingsText(Params, Args.data(), Args.size());
8850 Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
8851 const TemplateArgument *Args,
8853 SmallString<128> Str;
8854 llvm::raw_svector_ostream Out(Str);
8856 if (!Params || Params->size() == 0 || NumArgs == 0)
8857 return std::string();
8859 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
8868 if (const IdentifierInfo *Id = Params->getParam(I)->getIdentifier()) {
8869 Out << Id->getName();
8875 Args[I].print(getPrintingPolicy(), Out);
8882 void Sema::MarkAsLateParsedTemplate(FunctionDecl *FD, Decl *FnD,
8883 CachedTokens &Toks) {
8887 auto LPT = llvm::make_unique<LateParsedTemplate>();
8889 // Take tokens to avoid allocations
8890 LPT->Toks.swap(Toks);
8892 LateParsedTemplateMap.insert(std::make_pair(FD, std::move(LPT)));
8894 FD->setLateTemplateParsed(true);
8897 void Sema::UnmarkAsLateParsedTemplate(FunctionDecl *FD) {
8900 FD->setLateTemplateParsed(false);
8903 bool Sema::IsInsideALocalClassWithinATemplateFunction() {
8904 DeclContext *DC = CurContext;
8907 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(CurContext)) {
8908 const FunctionDecl *FD = RD->isLocalClass();
8909 return (FD && FD->getTemplatedKind() != FunctionDecl::TK_NonTemplate);
8910 } else if (DC->isTranslationUnit() || DC->isNamespace())
8913 DC = DC->getParent();
8919 /// \brief Walk the path from which a declaration was instantiated, and check
8920 /// that every explicit specialization along that path is visible. This enforces
8921 /// C++ [temp.expl.spec]/6:
8923 /// If a template, a member template or a member of a class template is
8924 /// explicitly specialized then that specialization shall be declared before
8925 /// the first use of that specialization that would cause an implicit
8926 /// instantiation to take place, in every translation unit in which such a
8927 /// use occurs; no diagnostic is required.
8929 /// and also C++ [temp.class.spec]/1:
8931 /// A partial specialization shall be declared before the first use of a
8932 /// class template specialization that would make use of the partial
8933 /// specialization as the result of an implicit or explicit instantiation
8934 /// in every translation unit in which such a use occurs; no diagnostic is
8936 class ExplicitSpecializationVisibilityChecker {
8939 llvm::SmallVector<Module *, 8> Modules;
8942 ExplicitSpecializationVisibilityChecker(Sema &S, SourceLocation Loc)
8945 void check(NamedDecl *ND) {
8946 if (auto *FD = dyn_cast<FunctionDecl>(ND))
8947 return checkImpl(FD);
8948 if (auto *RD = dyn_cast<CXXRecordDecl>(ND))
8949 return checkImpl(RD);
8950 if (auto *VD = dyn_cast<VarDecl>(ND))
8951 return checkImpl(VD);
8952 if (auto *ED = dyn_cast<EnumDecl>(ND))
8953 return checkImpl(ED);
8957 void diagnose(NamedDecl *D, bool IsPartialSpec) {
8958 auto Kind = IsPartialSpec ? Sema::MissingImportKind::PartialSpecialization
8959 : Sema::MissingImportKind::ExplicitSpecialization;
8960 const bool Recover = true;
8962 // If we got a custom set of modules (because only a subset of the
8963 // declarations are interesting), use them, otherwise let
8964 // diagnoseMissingImport intelligently pick some.
8965 if (Modules.empty())
8966 S.diagnoseMissingImport(Loc, D, Kind, Recover);
8968 S.diagnoseMissingImport(Loc, D, D->getLocation(), Modules, Kind, Recover);
8971 // Check a specific declaration. There are three problematic cases:
8973 // 1) The declaration is an explicit specialization of a template
8975 // 2) The declaration is an explicit specialization of a member of an
8977 // 3) The declaration is an instantiation of a template, and that template
8978 // is an explicit specialization of a member of a templated class.
8980 // We don't need to go any deeper than that, as the instantiation of the
8981 // surrounding class / etc is not triggered by whatever triggered this
8982 // instantiation, and thus should be checked elsewhere.
8983 template<typename SpecDecl>
8984 void checkImpl(SpecDecl *Spec) {
8985 bool IsHiddenExplicitSpecialization = false;
8986 if (Spec->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) {
8987 IsHiddenExplicitSpecialization =
8988 Spec->getMemberSpecializationInfo()
8989 ? !S.hasVisibleMemberSpecialization(Spec, &Modules)
8990 : !S.hasVisibleDeclaration(Spec);
8992 checkInstantiated(Spec);
8995 if (IsHiddenExplicitSpecialization)
8996 diagnose(Spec->getMostRecentDecl(), false);
8999 void checkInstantiated(FunctionDecl *FD) {
9000 if (auto *TD = FD->getPrimaryTemplate())
9004 void checkInstantiated(CXXRecordDecl *RD) {
9005 auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(RD);
9009 auto From = SD->getSpecializedTemplateOrPartial();
9010 if (auto *TD = From.dyn_cast<ClassTemplateDecl *>())
9013 From.dyn_cast<ClassTemplatePartialSpecializationDecl *>()) {
9014 if (!S.hasVisibleDeclaration(TD))
9020 void checkInstantiated(VarDecl *RD) {
9021 auto *SD = dyn_cast<VarTemplateSpecializationDecl>(RD);
9025 auto From = SD->getSpecializedTemplateOrPartial();
9026 if (auto *TD = From.dyn_cast<VarTemplateDecl *>())
9029 From.dyn_cast<VarTemplatePartialSpecializationDecl *>()) {
9030 if (!S.hasVisibleDeclaration(TD))
9036 void checkInstantiated(EnumDecl *FD) {}
9038 template<typename TemplDecl>
9039 void checkTemplate(TemplDecl *TD) {
9040 if (TD->isMemberSpecialization()) {
9041 if (!S.hasVisibleMemberSpecialization(TD, &Modules))
9042 diagnose(TD->getMostRecentDecl(), false);
9046 } // end anonymous namespace
9048 void Sema::checkSpecializationVisibility(SourceLocation Loc, NamedDecl *Spec) {
9049 if (!getLangOpts().Modules)
9052 ExplicitSpecializationVisibilityChecker(*this, Loc).check(Spec);
9055 /// \brief Check whether a template partial specialization that we've discovered
9056 /// is hidden, and produce suitable diagnostics if so.
9057 void Sema::checkPartialSpecializationVisibility(SourceLocation Loc,
9059 llvm::SmallVector<Module *, 8> Modules;
9060 if (!hasVisibleDeclaration(Spec, &Modules))
9061 diagnoseMissingImport(Loc, Spec, Spec->getLocation(), Modules,
9062 MissingImportKind::PartialSpecialization,