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 if (!MightBeCxx11UnevalField && !isAddressOfOperand &&
433 isa<CXXMethodDecl>(DC) && cast<CXXMethodDecl>(DC)->isInstance()) {
434 QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType(Context);
436 // Since the 'this' expression is synthesized, we don't need to
437 // perform the double-lookup check.
438 NamedDecl *FirstQualifierInScope = nullptr;
440 return CXXDependentScopeMemberExpr::Create(
441 Context, /*This*/ nullptr, ThisType, /*IsArrow*/ true,
442 /*Op*/ SourceLocation(), SS.getWithLocInContext(Context), TemplateKWLoc,
443 FirstQualifierInScope, NameInfo, TemplateArgs);
446 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
450 Sema::BuildDependentDeclRefExpr(const CXXScopeSpec &SS,
451 SourceLocation TemplateKWLoc,
452 const DeclarationNameInfo &NameInfo,
453 const TemplateArgumentListInfo *TemplateArgs) {
454 return DependentScopeDeclRefExpr::Create(
455 Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo,
459 /// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining
460 /// that the template parameter 'PrevDecl' is being shadowed by a new
461 /// declaration at location Loc. Returns true to indicate that this is
462 /// an error, and false otherwise.
463 void Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl) {
464 assert(PrevDecl->isTemplateParameter() && "Not a template parameter");
466 // Microsoft Visual C++ permits template parameters to be shadowed.
467 if (getLangOpts().MicrosoftExt)
470 // C++ [temp.local]p4:
471 // A template-parameter shall not be redeclared within its
472 // scope (including nested scopes).
473 Diag(Loc, diag::err_template_param_shadow)
474 << cast<NamedDecl>(PrevDecl)->getDeclName();
475 Diag(PrevDecl->getLocation(), diag::note_template_param_here);
478 /// AdjustDeclIfTemplate - If the given decl happens to be a template, reset
479 /// the parameter D to reference the templated declaration and return a pointer
480 /// to the template declaration. Otherwise, do nothing to D and return null.
481 TemplateDecl *Sema::AdjustDeclIfTemplate(Decl *&D) {
482 if (TemplateDecl *Temp = dyn_cast_or_null<TemplateDecl>(D)) {
483 D = Temp->getTemplatedDecl();
489 ParsedTemplateArgument ParsedTemplateArgument::getTemplatePackExpansion(
490 SourceLocation EllipsisLoc) const {
491 assert(Kind == Template &&
492 "Only template template arguments can be pack expansions here");
493 assert(getAsTemplate().get().containsUnexpandedParameterPack() &&
494 "Template template argument pack expansion without packs");
495 ParsedTemplateArgument Result(*this);
496 Result.EllipsisLoc = EllipsisLoc;
500 static TemplateArgumentLoc translateTemplateArgument(Sema &SemaRef,
501 const ParsedTemplateArgument &Arg) {
503 switch (Arg.getKind()) {
504 case ParsedTemplateArgument::Type: {
506 QualType T = SemaRef.GetTypeFromParser(Arg.getAsType(), &DI);
508 DI = SemaRef.Context.getTrivialTypeSourceInfo(T, Arg.getLocation());
509 return TemplateArgumentLoc(TemplateArgument(T), DI);
512 case ParsedTemplateArgument::NonType: {
513 Expr *E = static_cast<Expr *>(Arg.getAsExpr());
514 return TemplateArgumentLoc(TemplateArgument(E), E);
517 case ParsedTemplateArgument::Template: {
518 TemplateName Template = Arg.getAsTemplate().get();
519 TemplateArgument TArg;
520 if (Arg.getEllipsisLoc().isValid())
521 TArg = TemplateArgument(Template, Optional<unsigned int>());
524 return TemplateArgumentLoc(TArg,
525 Arg.getScopeSpec().getWithLocInContext(
528 Arg.getEllipsisLoc());
532 llvm_unreachable("Unhandled parsed template argument");
535 /// \brief Translates template arguments as provided by the parser
536 /// into template arguments used by semantic analysis.
537 void Sema::translateTemplateArguments(const ASTTemplateArgsPtr &TemplateArgsIn,
538 TemplateArgumentListInfo &TemplateArgs) {
539 for (unsigned I = 0, Last = TemplateArgsIn.size(); I != Last; ++I)
540 TemplateArgs.addArgument(translateTemplateArgument(*this,
544 static void maybeDiagnoseTemplateParameterShadow(Sema &SemaRef, Scope *S,
546 IdentifierInfo *Name) {
547 NamedDecl *PrevDecl = SemaRef.LookupSingleName(
548 S, Name, Loc, Sema::LookupOrdinaryName, Sema::ForRedeclaration);
549 if (PrevDecl && PrevDecl->isTemplateParameter())
550 SemaRef.DiagnoseTemplateParameterShadow(Loc, PrevDecl);
553 /// ActOnTypeParameter - Called when a C++ template type parameter
554 /// (e.g., "typename T") has been parsed. Typename specifies whether
555 /// the keyword "typename" was used to declare the type parameter
556 /// (otherwise, "class" was used), and KeyLoc is the location of the
557 /// "class" or "typename" keyword. ParamName is the name of the
558 /// parameter (NULL indicates an unnamed template parameter) and
559 /// ParamNameLoc is the location of the parameter name (if any).
560 /// If the type parameter has a default argument, it will be added
561 /// later via ActOnTypeParameterDefault.
562 Decl *Sema::ActOnTypeParameter(Scope *S, bool Typename,
563 SourceLocation EllipsisLoc,
564 SourceLocation KeyLoc,
565 IdentifierInfo *ParamName,
566 SourceLocation ParamNameLoc,
567 unsigned Depth, unsigned Position,
568 SourceLocation EqualLoc,
569 ParsedType DefaultArg) {
570 assert(S->isTemplateParamScope() &&
571 "Template type parameter not in template parameter scope!");
573 SourceLocation Loc = ParamNameLoc;
577 bool IsParameterPack = EllipsisLoc.isValid();
578 TemplateTypeParmDecl *Param
579 = TemplateTypeParmDecl::Create(Context, Context.getTranslationUnitDecl(),
580 KeyLoc, Loc, Depth, Position, ParamName,
581 Typename, IsParameterPack);
582 Param->setAccess(AS_public);
585 maybeDiagnoseTemplateParameterShadow(*this, S, ParamNameLoc, ParamName);
587 // Add the template parameter into the current scope.
589 IdResolver.AddDecl(Param);
592 // C++0x [temp.param]p9:
593 // A default template-argument may be specified for any kind of
594 // template-parameter that is not a template parameter pack.
595 if (DefaultArg && IsParameterPack) {
596 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
597 DefaultArg = nullptr;
600 // Handle the default argument, if provided.
602 TypeSourceInfo *DefaultTInfo;
603 GetTypeFromParser(DefaultArg, &DefaultTInfo);
605 assert(DefaultTInfo && "expected source information for type");
607 // Check for unexpanded parameter packs.
608 if (DiagnoseUnexpandedParameterPack(Loc, DefaultTInfo,
609 UPPC_DefaultArgument))
612 // Check the template argument itself.
613 if (CheckTemplateArgument(Param, DefaultTInfo)) {
614 Param->setInvalidDecl();
618 Param->setDefaultArgument(DefaultTInfo);
624 /// \brief Check that the type of a non-type template parameter is
627 /// \returns the (possibly-promoted) parameter type if valid;
628 /// otherwise, produces a diagnostic and returns a NULL type.
630 Sema::CheckNonTypeTemplateParameterType(QualType T, SourceLocation Loc) {
631 // We don't allow variably-modified types as the type of non-type template
633 if (T->isVariablyModifiedType()) {
634 Diag(Loc, diag::err_variably_modified_nontype_template_param)
639 // C++ [temp.param]p4:
641 // A non-type template-parameter shall have one of the following
642 // (optionally cv-qualified) types:
644 // -- integral or enumeration type,
645 if (T->isIntegralOrEnumerationType() ||
646 // -- pointer to object or pointer to function,
647 T->isPointerType() ||
648 // -- reference to object or reference to function,
649 T->isReferenceType() ||
650 // -- pointer to member,
651 T->isMemberPointerType() ||
652 // -- std::nullptr_t.
653 T->isNullPtrType() ||
654 // If T is a dependent type, we can't do the check now, so we
655 // assume that it is well-formed.
656 T->isDependentType()) {
657 // C++ [temp.param]p5: The top-level cv-qualifiers on the template-parameter
658 // are ignored when determining its type.
659 return T.getUnqualifiedType();
662 // C++ [temp.param]p8:
664 // A non-type template-parameter of type "array of T" or
665 // "function returning T" is adjusted to be of type "pointer to
666 // T" or "pointer to function returning T", respectively.
667 else if (T->isArrayType() || T->isFunctionType())
668 return Context.getDecayedType(T);
670 Diag(Loc, diag::err_template_nontype_parm_bad_type)
676 Decl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
679 SourceLocation EqualLoc,
681 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
682 QualType T = TInfo->getType();
684 assert(S->isTemplateParamScope() &&
685 "Non-type template parameter not in template parameter scope!");
686 bool Invalid = false;
688 T = CheckNonTypeTemplateParameterType(T, D.getIdentifierLoc());
690 T = Context.IntTy; // Recover with an 'int' type.
694 IdentifierInfo *ParamName = D.getIdentifier();
695 bool IsParameterPack = D.hasEllipsis();
696 NonTypeTemplateParmDecl *Param
697 = NonTypeTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
699 D.getIdentifierLoc(),
700 Depth, Position, ParamName, T,
701 IsParameterPack, TInfo);
702 Param->setAccess(AS_public);
705 Param->setInvalidDecl();
708 maybeDiagnoseTemplateParameterShadow(*this, S, D.getIdentifierLoc(),
711 // Add the template parameter into the current scope.
713 IdResolver.AddDecl(Param);
716 // C++0x [temp.param]p9:
717 // A default template-argument may be specified for any kind of
718 // template-parameter that is not a template parameter pack.
719 if (Default && IsParameterPack) {
720 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
724 // Check the well-formedness of the default template argument, if provided.
726 // Check for unexpanded parameter packs.
727 if (DiagnoseUnexpandedParameterPack(Default, UPPC_DefaultArgument))
730 TemplateArgument Converted;
731 ExprResult DefaultRes =
732 CheckTemplateArgument(Param, Param->getType(), Default, Converted);
733 if (DefaultRes.isInvalid()) {
734 Param->setInvalidDecl();
737 Default = DefaultRes.get();
739 Param->setDefaultArgument(Default);
745 /// ActOnTemplateTemplateParameter - Called when a C++ template template
746 /// parameter (e.g. T in template <template \<typename> class T> class array)
747 /// has been parsed. S is the current scope.
748 Decl *Sema::ActOnTemplateTemplateParameter(Scope* S,
749 SourceLocation TmpLoc,
750 TemplateParameterList *Params,
751 SourceLocation EllipsisLoc,
752 IdentifierInfo *Name,
753 SourceLocation NameLoc,
756 SourceLocation EqualLoc,
757 ParsedTemplateArgument Default) {
758 assert(S->isTemplateParamScope() &&
759 "Template template parameter not in template parameter scope!");
761 // Construct the parameter object.
762 bool IsParameterPack = EllipsisLoc.isValid();
763 TemplateTemplateParmDecl *Param =
764 TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
765 NameLoc.isInvalid()? TmpLoc : NameLoc,
766 Depth, Position, IsParameterPack,
768 Param->setAccess(AS_public);
770 // If the template template parameter has a name, then link the identifier
771 // into the scope and lookup mechanisms.
773 maybeDiagnoseTemplateParameterShadow(*this, S, NameLoc, Name);
776 IdResolver.AddDecl(Param);
779 if (Params->size() == 0) {
780 Diag(Param->getLocation(), diag::err_template_template_parm_no_parms)
781 << SourceRange(Params->getLAngleLoc(), Params->getRAngleLoc());
782 Param->setInvalidDecl();
785 // C++0x [temp.param]p9:
786 // A default template-argument may be specified for any kind of
787 // template-parameter that is not a template parameter pack.
788 if (IsParameterPack && !Default.isInvalid()) {
789 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
790 Default = ParsedTemplateArgument();
793 if (!Default.isInvalid()) {
794 // Check only that we have a template template argument. We don't want to
795 // try to check well-formedness now, because our template template parameter
796 // might have dependent types in its template parameters, which we wouldn't
797 // be able to match now.
799 // If none of the template template parameter's template arguments mention
800 // other template parameters, we could actually perform more checking here.
801 // However, it isn't worth doing.
802 TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default);
803 if (DefaultArg.getArgument().getAsTemplate().isNull()) {
804 Diag(DefaultArg.getLocation(), diag::err_template_arg_not_valid_template)
805 << DefaultArg.getSourceRange();
809 // Check for unexpanded parameter packs.
810 if (DiagnoseUnexpandedParameterPack(DefaultArg.getLocation(),
811 DefaultArg.getArgument().getAsTemplate(),
812 UPPC_DefaultArgument))
815 Param->setDefaultArgument(Context, DefaultArg);
821 /// ActOnTemplateParameterList - Builds a TemplateParameterList, optionally
822 /// constrained by RequiresClause, that contains the template parameters in
824 TemplateParameterList *
825 Sema::ActOnTemplateParameterList(unsigned Depth,
826 SourceLocation ExportLoc,
827 SourceLocation TemplateLoc,
828 SourceLocation LAngleLoc,
829 ArrayRef<Decl *> Params,
830 SourceLocation RAngleLoc,
831 Expr *RequiresClause) {
832 if (ExportLoc.isValid())
833 Diag(ExportLoc, diag::warn_template_export_unsupported);
835 // FIXME: store RequiresClause
836 return TemplateParameterList::Create(
837 Context, TemplateLoc, LAngleLoc,
838 llvm::makeArrayRef((NamedDecl *const *)Params.data(), Params.size()),
842 static void SetNestedNameSpecifier(TagDecl *T, const CXXScopeSpec &SS) {
844 T->setQualifierInfo(SS.getWithLocInContext(T->getASTContext()));
848 Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
849 SourceLocation KWLoc, CXXScopeSpec &SS,
850 IdentifierInfo *Name, SourceLocation NameLoc,
852 TemplateParameterList *TemplateParams,
853 AccessSpecifier AS, SourceLocation ModulePrivateLoc,
854 SourceLocation FriendLoc,
855 unsigned NumOuterTemplateParamLists,
856 TemplateParameterList** OuterTemplateParamLists,
857 SkipBodyInfo *SkipBody) {
858 assert(TemplateParams && TemplateParams->size() > 0 &&
859 "No template parameters");
860 assert(TUK != TUK_Reference && "Can only declare or define class templates");
861 bool Invalid = false;
863 // Check that we can declare a template here.
864 if (CheckTemplateDeclScope(S, TemplateParams))
867 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
868 assert(Kind != TTK_Enum && "can't build template of enumerated type");
870 // There is no such thing as an unnamed class template.
872 Diag(KWLoc, diag::err_template_unnamed_class);
876 // Find any previous declaration with this name. For a friend with no
877 // scope explicitly specified, we only look for tag declarations (per
878 // C++11 [basic.lookup.elab]p2).
879 DeclContext *SemanticContext;
880 LookupResult Previous(*this, Name, NameLoc,
881 (SS.isEmpty() && TUK == TUK_Friend)
882 ? LookupTagName : LookupOrdinaryName,
884 if (SS.isNotEmpty() && !SS.isInvalid()) {
885 SemanticContext = computeDeclContext(SS, true);
886 if (!SemanticContext) {
887 // FIXME: Horrible, horrible hack! We can't currently represent this
888 // in the AST, and historically we have just ignored such friend
889 // class templates, so don't complain here.
890 Diag(NameLoc, TUK == TUK_Friend
891 ? diag::warn_template_qualified_friend_ignored
892 : diag::err_template_qualified_declarator_no_match)
893 << SS.getScopeRep() << SS.getRange();
894 return TUK != TUK_Friend;
897 if (RequireCompleteDeclContext(SS, SemanticContext))
900 // If we're adding a template to a dependent context, we may need to
901 // rebuilding some of the types used within the template parameter list,
902 // now that we know what the current instantiation is.
903 if (SemanticContext->isDependentContext()) {
904 ContextRAII SavedContext(*this, SemanticContext);
905 if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
907 } else if (TUK != TUK_Friend && TUK != TUK_Reference)
908 diagnoseQualifiedDeclaration(SS, SemanticContext, Name, NameLoc);
910 LookupQualifiedName(Previous, SemanticContext);
912 SemanticContext = CurContext;
914 // C++14 [class.mem]p14:
915 // If T is the name of a class, then each of the following shall have a
916 // name different from T:
917 // -- every member template of class T
918 if (TUK != TUK_Friend &&
919 DiagnoseClassNameShadow(SemanticContext,
920 DeclarationNameInfo(Name, NameLoc)))
923 LookupName(Previous, S);
926 if (Previous.isAmbiguous())
929 NamedDecl *PrevDecl = nullptr;
930 if (Previous.begin() != Previous.end())
931 PrevDecl = (*Previous.begin())->getUnderlyingDecl();
933 if (PrevDecl && PrevDecl->isTemplateParameter()) {
934 // Maybe we will complain about the shadowed template parameter.
935 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl);
936 // Just pretend that we didn't see the previous declaration.
940 // If there is a previous declaration with the same name, check
941 // whether this is a valid redeclaration.
942 ClassTemplateDecl *PrevClassTemplate
943 = dyn_cast_or_null<ClassTemplateDecl>(PrevDecl);
945 // We may have found the injected-class-name of a class template,
946 // class template partial specialization, or class template specialization.
947 // In these cases, grab the template that is being defined or specialized.
948 if (!PrevClassTemplate && PrevDecl && isa<CXXRecordDecl>(PrevDecl) &&
949 cast<CXXRecordDecl>(PrevDecl)->isInjectedClassName()) {
950 PrevDecl = cast<CXXRecordDecl>(PrevDecl->getDeclContext());
952 = cast<CXXRecordDecl>(PrevDecl)->getDescribedClassTemplate();
953 if (!PrevClassTemplate && isa<ClassTemplateSpecializationDecl>(PrevDecl)) {
955 = cast<ClassTemplateSpecializationDecl>(PrevDecl)
956 ->getSpecializedTemplate();
960 if (TUK == TUK_Friend) {
961 // C++ [namespace.memdef]p3:
962 // [...] When looking for a prior declaration of a class or a function
963 // declared as a friend, and when the name of the friend class or
964 // function is neither a qualified name nor a template-id, scopes outside
965 // the innermost enclosing namespace scope are not considered.
967 DeclContext *OutermostContext = CurContext;
968 while (!OutermostContext->isFileContext())
969 OutermostContext = OutermostContext->getLookupParent();
972 (OutermostContext->Equals(PrevDecl->getDeclContext()) ||
973 OutermostContext->Encloses(PrevDecl->getDeclContext()))) {
974 SemanticContext = PrevDecl->getDeclContext();
976 // Declarations in outer scopes don't matter. However, the outermost
977 // context we computed is the semantic context for our new
979 PrevDecl = PrevClassTemplate = nullptr;
980 SemanticContext = OutermostContext;
982 // Check that the chosen semantic context doesn't already contain a
983 // declaration of this name as a non-tag type.
984 Previous.clear(LookupOrdinaryName);
985 DeclContext *LookupContext = SemanticContext;
986 while (LookupContext->isTransparentContext())
987 LookupContext = LookupContext->getLookupParent();
988 LookupQualifiedName(Previous, LookupContext);
990 if (Previous.isAmbiguous())
993 if (Previous.begin() != Previous.end())
994 PrevDecl = (*Previous.begin())->getUnderlyingDecl();
997 } else if (PrevDecl &&
998 !isDeclInScope(Previous.getRepresentativeDecl(), SemanticContext,
1000 PrevDecl = PrevClassTemplate = nullptr;
1002 if (auto *Shadow = dyn_cast_or_null<UsingShadowDecl>(
1003 PrevDecl ? Previous.getRepresentativeDecl() : nullptr)) {
1005 !(PrevClassTemplate &&
1006 PrevClassTemplate->getDeclContext()->getRedeclContext()->Equals(
1007 SemanticContext->getRedeclContext()))) {
1008 Diag(KWLoc, diag::err_using_decl_conflict_reverse);
1009 Diag(Shadow->getTargetDecl()->getLocation(),
1010 diag::note_using_decl_target);
1011 Diag(Shadow->getUsingDecl()->getLocation(), diag::note_using_decl) << 0;
1012 // Recover by ignoring the old declaration.
1013 PrevDecl = PrevClassTemplate = nullptr;
1017 if (PrevClassTemplate) {
1018 // Ensure that the template parameter lists are compatible. Skip this check
1019 // for a friend in a dependent context: the template parameter list itself
1020 // could be dependent.
1021 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
1022 !TemplateParameterListsAreEqual(TemplateParams,
1023 PrevClassTemplate->getTemplateParameters(),
1028 // C++ [temp.class]p4:
1029 // In a redeclaration, partial specialization, explicit
1030 // specialization or explicit instantiation of a class template,
1031 // the class-key shall agree in kind with the original class
1032 // template declaration (7.1.5.3).
1033 RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl();
1034 if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind,
1035 TUK == TUK_Definition, KWLoc, Name)) {
1036 Diag(KWLoc, diag::err_use_with_wrong_tag)
1038 << FixItHint::CreateReplacement(KWLoc, PrevRecordDecl->getKindName());
1039 Diag(PrevRecordDecl->getLocation(), diag::note_previous_use);
1040 Kind = PrevRecordDecl->getTagKind();
1043 // Check for redefinition of this class template.
1044 if (TUK == TUK_Definition) {
1045 if (TagDecl *Def = PrevRecordDecl->getDefinition()) {
1046 // If we have a prior definition that is not visible, treat this as
1047 // simply making that previous definition visible.
1048 NamedDecl *Hidden = nullptr;
1049 if (SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
1050 SkipBody->ShouldSkip = true;
1051 auto *Tmpl = cast<CXXRecordDecl>(Hidden)->getDescribedClassTemplate();
1052 assert(Tmpl && "original definition of a class template is not a "
1054 makeMergedDefinitionVisible(Hidden, KWLoc);
1055 makeMergedDefinitionVisible(Tmpl, KWLoc);
1059 Diag(NameLoc, diag::err_redefinition) << Name;
1060 Diag(Def->getLocation(), diag::note_previous_definition);
1061 // FIXME: Would it make sense to try to "forget" the previous
1062 // definition, as part of error recovery?
1066 } else if (PrevDecl) {
1068 // A class template shall not have the same name as any other
1069 // template, class, function, object, enumeration, enumerator,
1070 // namespace, or type in the same scope (3.3), except as specified
1072 Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
1073 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1077 // Check the template parameter list of this declaration, possibly
1078 // merging in the template parameter list from the previous class
1079 // template declaration. Skip this check for a friend in a dependent
1080 // context, because the template parameter list might be dependent.
1081 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
1082 CheckTemplateParameterList(
1084 PrevClassTemplate ? PrevClassTemplate->getTemplateParameters()
1086 (SS.isSet() && SemanticContext && SemanticContext->isRecord() &&
1087 SemanticContext->isDependentContext())
1088 ? TPC_ClassTemplateMember
1089 : TUK == TUK_Friend ? TPC_FriendClassTemplate
1090 : TPC_ClassTemplate))
1094 // If the name of the template was qualified, we must be defining the
1095 // template out-of-line.
1096 if (!SS.isInvalid() && !Invalid && !PrevClassTemplate) {
1097 Diag(NameLoc, TUK == TUK_Friend ? diag::err_friend_decl_does_not_match
1098 : diag::err_member_decl_does_not_match)
1099 << Name << SemanticContext << /*IsDefinition*/true << SS.getRange();
1104 CXXRecordDecl *NewClass =
1105 CXXRecordDecl::Create(Context, Kind, SemanticContext, KWLoc, NameLoc, Name,
1107 PrevClassTemplate->getTemplatedDecl() : nullptr,
1108 /*DelayTypeCreation=*/true);
1109 SetNestedNameSpecifier(NewClass, SS);
1110 if (NumOuterTemplateParamLists > 0)
1111 NewClass->setTemplateParameterListsInfo(
1112 Context, llvm::makeArrayRef(OuterTemplateParamLists,
1113 NumOuterTemplateParamLists));
1115 // Add alignment attributes if necessary; these attributes are checked when
1116 // the ASTContext lays out the structure.
1117 if (TUK == TUK_Definition) {
1118 AddAlignmentAttributesForRecord(NewClass);
1119 AddMsStructLayoutForRecord(NewClass);
1122 ClassTemplateDecl *NewTemplate
1123 = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc,
1124 DeclarationName(Name), TemplateParams,
1125 NewClass, PrevClassTemplate);
1126 NewClass->setDescribedClassTemplate(NewTemplate);
1128 if (ModulePrivateLoc.isValid())
1129 NewTemplate->setModulePrivate();
1131 // Build the type for the class template declaration now.
1132 QualType T = NewTemplate->getInjectedClassNameSpecialization();
1133 T = Context.getInjectedClassNameType(NewClass, T);
1134 assert(T->isDependentType() && "Class template type is not dependent?");
1137 // If we are providing an explicit specialization of a member that is a
1138 // class template, make a note of that.
1139 if (PrevClassTemplate &&
1140 PrevClassTemplate->getInstantiatedFromMemberTemplate())
1141 PrevClassTemplate->setMemberSpecialization();
1143 // Set the access specifier.
1144 if (!Invalid && TUK != TUK_Friend && NewTemplate->getDeclContext()->isRecord())
1145 SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS);
1147 // Set the lexical context of these templates
1148 NewClass->setLexicalDeclContext(CurContext);
1149 NewTemplate->setLexicalDeclContext(CurContext);
1151 if (TUK == TUK_Definition)
1152 NewClass->startDefinition();
1155 ProcessDeclAttributeList(S, NewClass, Attr);
1157 if (PrevClassTemplate)
1158 mergeDeclAttributes(NewClass, PrevClassTemplate->getTemplatedDecl());
1160 AddPushedVisibilityAttribute(NewClass);
1162 if (TUK != TUK_Friend) {
1163 // Per C++ [basic.scope.temp]p2, skip the template parameter scopes.
1165 while ((Outer->getFlags() & Scope::TemplateParamScope) != 0)
1166 Outer = Outer->getParent();
1167 PushOnScopeChains(NewTemplate, Outer);
1169 if (PrevClassTemplate && PrevClassTemplate->getAccess() != AS_none) {
1170 NewTemplate->setAccess(PrevClassTemplate->getAccess());
1171 NewClass->setAccess(PrevClassTemplate->getAccess());
1174 NewTemplate->setObjectOfFriendDecl();
1176 // Friend templates are visible in fairly strange ways.
1177 if (!CurContext->isDependentContext()) {
1178 DeclContext *DC = SemanticContext->getRedeclContext();
1179 DC->makeDeclVisibleInContext(NewTemplate);
1180 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
1181 PushOnScopeChains(NewTemplate, EnclosingScope,
1182 /* AddToContext = */ false);
1185 FriendDecl *Friend = FriendDecl::Create(
1186 Context, CurContext, NewClass->getLocation(), NewTemplate, FriendLoc);
1187 Friend->setAccess(AS_public);
1188 CurContext->addDecl(Friend);
1192 NewTemplate->setInvalidDecl();
1193 NewClass->setInvalidDecl();
1196 ActOnDocumentableDecl(NewTemplate);
1201 /// \brief Diagnose the presence of a default template argument on a
1202 /// template parameter, which is ill-formed in certain contexts.
1204 /// \returns true if the default template argument should be dropped.
1205 static bool DiagnoseDefaultTemplateArgument(Sema &S,
1206 Sema::TemplateParamListContext TPC,
1207 SourceLocation ParamLoc,
1208 SourceRange DefArgRange) {
1210 case Sema::TPC_ClassTemplate:
1211 case Sema::TPC_VarTemplate:
1212 case Sema::TPC_TypeAliasTemplate:
1215 case Sema::TPC_FunctionTemplate:
1216 case Sema::TPC_FriendFunctionTemplateDefinition:
1217 // C++ [temp.param]p9:
1218 // A default template-argument shall not be specified in a
1219 // function template declaration or a function template
1221 // If a friend function template declaration specifies a default
1222 // template-argument, that declaration shall be a definition and shall be
1223 // the only declaration of the function template in the translation unit.
1224 // (C++98/03 doesn't have this wording; see DR226).
1225 S.Diag(ParamLoc, S.getLangOpts().CPlusPlus11 ?
1226 diag::warn_cxx98_compat_template_parameter_default_in_function_template
1227 : diag::ext_template_parameter_default_in_function_template)
1231 case Sema::TPC_ClassTemplateMember:
1232 // C++0x [temp.param]p9:
1233 // A default template-argument shall not be specified in the
1234 // template-parameter-lists of the definition of a member of a
1235 // class template that appears outside of the member's class.
1236 S.Diag(ParamLoc, diag::err_template_parameter_default_template_member)
1240 case Sema::TPC_FriendClassTemplate:
1241 case Sema::TPC_FriendFunctionTemplate:
1242 // C++ [temp.param]p9:
1243 // A default template-argument shall not be specified in a
1244 // friend template declaration.
1245 S.Diag(ParamLoc, diag::err_template_parameter_default_friend_template)
1249 // FIXME: C++0x [temp.param]p9 allows default template-arguments
1250 // for friend function templates if there is only a single
1251 // declaration (and it is a definition). Strange!
1254 llvm_unreachable("Invalid TemplateParamListContext!");
1257 /// \brief Check for unexpanded parameter packs within the template parameters
1258 /// of a template template parameter, recursively.
1259 static bool DiagnoseUnexpandedParameterPacks(Sema &S,
1260 TemplateTemplateParmDecl *TTP) {
1261 // A template template parameter which is a parameter pack is also a pack
1263 if (TTP->isParameterPack())
1266 TemplateParameterList *Params = TTP->getTemplateParameters();
1267 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
1268 NamedDecl *P = Params->getParam(I);
1269 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P)) {
1270 if (!NTTP->isParameterPack() &&
1271 S.DiagnoseUnexpandedParameterPack(NTTP->getLocation(),
1272 NTTP->getTypeSourceInfo(),
1273 Sema::UPPC_NonTypeTemplateParameterType))
1279 if (TemplateTemplateParmDecl *InnerTTP
1280 = dyn_cast<TemplateTemplateParmDecl>(P))
1281 if (DiagnoseUnexpandedParameterPacks(S, InnerTTP))
1288 /// \brief Checks the validity of a template parameter list, possibly
1289 /// considering the template parameter list from a previous
1292 /// If an "old" template parameter list is provided, it must be
1293 /// equivalent (per TemplateParameterListsAreEqual) to the "new"
1294 /// template parameter list.
1296 /// \param NewParams Template parameter list for a new template
1297 /// declaration. This template parameter list will be updated with any
1298 /// default arguments that are carried through from the previous
1299 /// template parameter list.
1301 /// \param OldParams If provided, template parameter list from a
1302 /// previous declaration of the same template. Default template
1303 /// arguments will be merged from the old template parameter list to
1304 /// the new template parameter list.
1306 /// \param TPC Describes the context in which we are checking the given
1307 /// template parameter list.
1309 /// \returns true if an error occurred, false otherwise.
1310 bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
1311 TemplateParameterList *OldParams,
1312 TemplateParamListContext TPC) {
1313 bool Invalid = false;
1315 // C++ [temp.param]p10:
1316 // The set of default template-arguments available for use with a
1317 // template declaration or definition is obtained by merging the
1318 // default arguments from the definition (if in scope) and all
1319 // declarations in scope in the same way default function
1320 // arguments are (8.3.6).
1321 bool SawDefaultArgument = false;
1322 SourceLocation PreviousDefaultArgLoc;
1324 // Dummy initialization to avoid warnings.
1325 TemplateParameterList::iterator OldParam = NewParams->end();
1327 OldParam = OldParams->begin();
1329 bool RemoveDefaultArguments = false;
1330 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
1331 NewParamEnd = NewParams->end();
1332 NewParam != NewParamEnd; ++NewParam) {
1333 // Variables used to diagnose redundant default arguments
1334 bool RedundantDefaultArg = false;
1335 SourceLocation OldDefaultLoc;
1336 SourceLocation NewDefaultLoc;
1338 // Variable used to diagnose missing default arguments
1339 bool MissingDefaultArg = false;
1341 // Variable used to diagnose non-final parameter packs
1342 bool SawParameterPack = false;
1344 if (TemplateTypeParmDecl *NewTypeParm
1345 = dyn_cast<TemplateTypeParmDecl>(*NewParam)) {
1346 // Check the presence of a default argument here.
1347 if (NewTypeParm->hasDefaultArgument() &&
1348 DiagnoseDefaultTemplateArgument(*this, TPC,
1349 NewTypeParm->getLocation(),
1350 NewTypeParm->getDefaultArgumentInfo()->getTypeLoc()
1352 NewTypeParm->removeDefaultArgument();
1354 // Merge default arguments for template type parameters.
1355 TemplateTypeParmDecl *OldTypeParm
1356 = OldParams? cast<TemplateTypeParmDecl>(*OldParam) : nullptr;
1357 if (NewTypeParm->isParameterPack()) {
1358 assert(!NewTypeParm->hasDefaultArgument() &&
1359 "Parameter packs can't have a default argument!");
1360 SawParameterPack = true;
1361 } else if (OldTypeParm && hasVisibleDefaultArgument(OldTypeParm) &&
1362 NewTypeParm->hasDefaultArgument()) {
1363 OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc();
1364 NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc();
1365 SawDefaultArgument = true;
1366 RedundantDefaultArg = true;
1367 PreviousDefaultArgLoc = NewDefaultLoc;
1368 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument()) {
1369 // Merge the default argument from the old declaration to the
1371 NewTypeParm->setInheritedDefaultArgument(Context, OldTypeParm);
1372 PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc();
1373 } else if (NewTypeParm->hasDefaultArgument()) {
1374 SawDefaultArgument = true;
1375 PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc();
1376 } else if (SawDefaultArgument)
1377 MissingDefaultArg = true;
1378 } else if (NonTypeTemplateParmDecl *NewNonTypeParm
1379 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) {
1380 // Check for unexpanded parameter packs.
1381 if (!NewNonTypeParm->isParameterPack() &&
1382 DiagnoseUnexpandedParameterPack(NewNonTypeParm->getLocation(),
1383 NewNonTypeParm->getTypeSourceInfo(),
1384 UPPC_NonTypeTemplateParameterType)) {
1389 // Check the presence of a default argument here.
1390 if (NewNonTypeParm->hasDefaultArgument() &&
1391 DiagnoseDefaultTemplateArgument(*this, TPC,
1392 NewNonTypeParm->getLocation(),
1393 NewNonTypeParm->getDefaultArgument()->getSourceRange())) {
1394 NewNonTypeParm->removeDefaultArgument();
1397 // Merge default arguments for non-type template parameters
1398 NonTypeTemplateParmDecl *OldNonTypeParm
1399 = OldParams? cast<NonTypeTemplateParmDecl>(*OldParam) : nullptr;
1400 if (NewNonTypeParm->isParameterPack()) {
1401 assert(!NewNonTypeParm->hasDefaultArgument() &&
1402 "Parameter packs can't have a default argument!");
1403 if (!NewNonTypeParm->isPackExpansion())
1404 SawParameterPack = true;
1405 } else if (OldNonTypeParm && hasVisibleDefaultArgument(OldNonTypeParm) &&
1406 NewNonTypeParm->hasDefaultArgument()) {
1407 OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc();
1408 NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc();
1409 SawDefaultArgument = true;
1410 RedundantDefaultArg = true;
1411 PreviousDefaultArgLoc = NewDefaultLoc;
1412 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument()) {
1413 // Merge the default argument from the old declaration to the
1415 NewNonTypeParm->setInheritedDefaultArgument(Context, OldNonTypeParm);
1416 PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc();
1417 } else if (NewNonTypeParm->hasDefaultArgument()) {
1418 SawDefaultArgument = true;
1419 PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc();
1420 } else if (SawDefaultArgument)
1421 MissingDefaultArg = true;
1423 TemplateTemplateParmDecl *NewTemplateParm
1424 = cast<TemplateTemplateParmDecl>(*NewParam);
1426 // Check for unexpanded parameter packs, recursively.
1427 if (::DiagnoseUnexpandedParameterPacks(*this, NewTemplateParm)) {
1432 // Check the presence of a default argument here.
1433 if (NewTemplateParm->hasDefaultArgument() &&
1434 DiagnoseDefaultTemplateArgument(*this, TPC,
1435 NewTemplateParm->getLocation(),
1436 NewTemplateParm->getDefaultArgument().getSourceRange()))
1437 NewTemplateParm->removeDefaultArgument();
1439 // Merge default arguments for template template parameters
1440 TemplateTemplateParmDecl *OldTemplateParm
1441 = OldParams? cast<TemplateTemplateParmDecl>(*OldParam) : nullptr;
1442 if (NewTemplateParm->isParameterPack()) {
1443 assert(!NewTemplateParm->hasDefaultArgument() &&
1444 "Parameter packs can't have a default argument!");
1445 if (!NewTemplateParm->isPackExpansion())
1446 SawParameterPack = true;
1447 } else if (OldTemplateParm &&
1448 hasVisibleDefaultArgument(OldTemplateParm) &&
1449 NewTemplateParm->hasDefaultArgument()) {
1450 OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation();
1451 NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation();
1452 SawDefaultArgument = true;
1453 RedundantDefaultArg = true;
1454 PreviousDefaultArgLoc = NewDefaultLoc;
1455 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument()) {
1456 // Merge the default argument from the old declaration to the
1458 NewTemplateParm->setInheritedDefaultArgument(Context, OldTemplateParm);
1459 PreviousDefaultArgLoc
1460 = OldTemplateParm->getDefaultArgument().getLocation();
1461 } else if (NewTemplateParm->hasDefaultArgument()) {
1462 SawDefaultArgument = true;
1463 PreviousDefaultArgLoc
1464 = NewTemplateParm->getDefaultArgument().getLocation();
1465 } else if (SawDefaultArgument)
1466 MissingDefaultArg = true;
1469 // C++11 [temp.param]p11:
1470 // If a template parameter of a primary class template or alias template
1471 // is a template parameter pack, it shall be the last template parameter.
1472 if (SawParameterPack && (NewParam + 1) != NewParamEnd &&
1473 (TPC == TPC_ClassTemplate || TPC == TPC_VarTemplate ||
1474 TPC == TPC_TypeAliasTemplate)) {
1475 Diag((*NewParam)->getLocation(),
1476 diag::err_template_param_pack_must_be_last_template_parameter);
1480 if (RedundantDefaultArg) {
1481 // C++ [temp.param]p12:
1482 // A template-parameter shall not be given default arguments
1483 // by two different declarations in the same scope.
1484 Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition);
1485 Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg);
1487 } else if (MissingDefaultArg && TPC != TPC_FunctionTemplate) {
1488 // C++ [temp.param]p11:
1489 // If a template-parameter of a class template has a default
1490 // template-argument, each subsequent template-parameter shall either
1491 // have a default template-argument supplied or be a template parameter
1493 Diag((*NewParam)->getLocation(),
1494 diag::err_template_param_default_arg_missing);
1495 Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg);
1497 RemoveDefaultArguments = true;
1500 // If we have an old template parameter list that we're merging
1501 // in, move on to the next parameter.
1506 // We were missing some default arguments at the end of the list, so remove
1507 // all of the default arguments.
1508 if (RemoveDefaultArguments) {
1509 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
1510 NewParamEnd = NewParams->end();
1511 NewParam != NewParamEnd; ++NewParam) {
1512 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*NewParam))
1513 TTP->removeDefaultArgument();
1514 else if (NonTypeTemplateParmDecl *NTTP
1515 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam))
1516 NTTP->removeDefaultArgument();
1518 cast<TemplateTemplateParmDecl>(*NewParam)->removeDefaultArgument();
1527 /// A class which looks for a use of a certain level of template
1529 struct DependencyChecker : RecursiveASTVisitor<DependencyChecker> {
1530 typedef RecursiveASTVisitor<DependencyChecker> super;
1534 SourceLocation MatchLoc;
1536 DependencyChecker(unsigned Depth) : Depth(Depth), Match(false) {}
1538 DependencyChecker(TemplateParameterList *Params) : Match(false) {
1539 NamedDecl *ND = Params->getParam(0);
1540 if (TemplateTypeParmDecl *PD = dyn_cast<TemplateTypeParmDecl>(ND)) {
1541 Depth = PD->getDepth();
1542 } else if (NonTypeTemplateParmDecl *PD =
1543 dyn_cast<NonTypeTemplateParmDecl>(ND)) {
1544 Depth = PD->getDepth();
1546 Depth = cast<TemplateTemplateParmDecl>(ND)->getDepth();
1550 bool Matches(unsigned ParmDepth, SourceLocation Loc = SourceLocation()) {
1551 if (ParmDepth >= Depth) {
1559 bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
1560 return !Matches(TL.getTypePtr()->getDepth(), TL.getNameLoc());
1563 bool VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
1564 return !Matches(T->getDepth());
1567 bool TraverseTemplateName(TemplateName N) {
1568 if (TemplateTemplateParmDecl *PD =
1569 dyn_cast_or_null<TemplateTemplateParmDecl>(N.getAsTemplateDecl()))
1570 if (Matches(PD->getDepth()))
1572 return super::TraverseTemplateName(N);
1575 bool VisitDeclRefExpr(DeclRefExpr *E) {
1576 if (NonTypeTemplateParmDecl *PD =
1577 dyn_cast<NonTypeTemplateParmDecl>(E->getDecl()))
1578 if (Matches(PD->getDepth(), E->getExprLoc()))
1580 return super::VisitDeclRefExpr(E);
1583 bool VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *T) {
1584 return TraverseType(T->getReplacementType());
1588 VisitSubstTemplateTypeParmPackType(const SubstTemplateTypeParmPackType *T) {
1589 return TraverseTemplateArgument(T->getArgumentPack());
1592 bool TraverseInjectedClassNameType(const InjectedClassNameType *T) {
1593 return TraverseType(T->getInjectedSpecializationType());
1596 } // end anonymous namespace
1598 /// Determines whether a given type depends on the given parameter
1601 DependsOnTemplateParameters(QualType T, TemplateParameterList *Params) {
1602 DependencyChecker Checker(Params);
1603 Checker.TraverseType(T);
1604 return Checker.Match;
1607 // Find the source range corresponding to the named type in the given
1608 // nested-name-specifier, if any.
1609 static SourceRange getRangeOfTypeInNestedNameSpecifier(ASTContext &Context,
1611 const CXXScopeSpec &SS) {
1612 NestedNameSpecifierLoc NNSLoc(SS.getScopeRep(), SS.location_data());
1613 while (NestedNameSpecifier *NNS = NNSLoc.getNestedNameSpecifier()) {
1614 if (const Type *CurType = NNS->getAsType()) {
1615 if (Context.hasSameUnqualifiedType(T, QualType(CurType, 0)))
1616 return NNSLoc.getTypeLoc().getSourceRange();
1620 NNSLoc = NNSLoc.getPrefix();
1623 return SourceRange();
1626 /// \brief Match the given template parameter lists to the given scope
1627 /// specifier, returning the template parameter list that applies to the
1630 /// \param DeclStartLoc the start of the declaration that has a scope
1631 /// specifier or a template parameter list.
1633 /// \param DeclLoc The location of the declaration itself.
1635 /// \param SS the scope specifier that will be matched to the given template
1636 /// parameter lists. This scope specifier precedes a qualified name that is
1639 /// \param TemplateId The template-id following the scope specifier, if there
1640 /// is one. Used to check for a missing 'template<>'.
1642 /// \param ParamLists the template parameter lists, from the outermost to the
1643 /// innermost template parameter lists.
1645 /// \param IsFriend Whether to apply the slightly different rules for
1646 /// matching template parameters to scope specifiers in friend
1649 /// \param IsExplicitSpecialization will be set true if the entity being
1650 /// declared is an explicit specialization, false otherwise.
1652 /// \returns the template parameter list, if any, that corresponds to the
1653 /// name that is preceded by the scope specifier @p SS. This template
1654 /// parameter list may have template parameters (if we're declaring a
1655 /// template) or may have no template parameters (if we're declaring a
1656 /// template specialization), or may be NULL (if what we're declaring isn't
1657 /// itself a template).
1658 TemplateParameterList *Sema::MatchTemplateParametersToScopeSpecifier(
1659 SourceLocation DeclStartLoc, SourceLocation DeclLoc, const CXXScopeSpec &SS,
1660 TemplateIdAnnotation *TemplateId,
1661 ArrayRef<TemplateParameterList *> ParamLists, bool IsFriend,
1662 bool &IsExplicitSpecialization, bool &Invalid) {
1663 IsExplicitSpecialization = false;
1666 // The sequence of nested types to which we will match up the template
1667 // parameter lists. We first build this list by starting with the type named
1668 // by the nested-name-specifier and walking out until we run out of types.
1669 SmallVector<QualType, 4> NestedTypes;
1671 if (SS.getScopeRep()) {
1672 if (CXXRecordDecl *Record
1673 = dyn_cast_or_null<CXXRecordDecl>(computeDeclContext(SS, true)))
1674 T = Context.getTypeDeclType(Record);
1676 T = QualType(SS.getScopeRep()->getAsType(), 0);
1679 // If we found an explicit specialization that prevents us from needing
1680 // 'template<>' headers, this will be set to the location of that
1681 // explicit specialization.
1682 SourceLocation ExplicitSpecLoc;
1684 while (!T.isNull()) {
1685 NestedTypes.push_back(T);
1687 // Retrieve the parent of a record type.
1688 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
1689 // If this type is an explicit specialization, we're done.
1690 if (ClassTemplateSpecializationDecl *Spec
1691 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
1692 if (!isa<ClassTemplatePartialSpecializationDecl>(Spec) &&
1693 Spec->getSpecializationKind() == TSK_ExplicitSpecialization) {
1694 ExplicitSpecLoc = Spec->getLocation();
1697 } else if (Record->getTemplateSpecializationKind()
1698 == TSK_ExplicitSpecialization) {
1699 ExplicitSpecLoc = Record->getLocation();
1703 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Record->getParent()))
1704 T = Context.getTypeDeclType(Parent);
1710 if (const TemplateSpecializationType *TST
1711 = T->getAs<TemplateSpecializationType>()) {
1712 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
1713 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Template->getDeclContext()))
1714 T = Context.getTypeDeclType(Parent);
1721 // Look one step prior in a dependent template specialization type.
1722 if (const DependentTemplateSpecializationType *DependentTST
1723 = T->getAs<DependentTemplateSpecializationType>()) {
1724 if (NestedNameSpecifier *NNS = DependentTST->getQualifier())
1725 T = QualType(NNS->getAsType(), 0);
1731 // Look one step prior in a dependent name type.
1732 if (const DependentNameType *DependentName = T->getAs<DependentNameType>()){
1733 if (NestedNameSpecifier *NNS = DependentName->getQualifier())
1734 T = QualType(NNS->getAsType(), 0);
1740 // Retrieve the parent of an enumeration type.
1741 if (const EnumType *EnumT = T->getAs<EnumType>()) {
1742 // FIXME: Forward-declared enums require a TSK_ExplicitSpecialization
1744 EnumDecl *Enum = EnumT->getDecl();
1746 // Get to the parent type.
1747 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Enum->getParent()))
1748 T = Context.getTypeDeclType(Parent);
1756 // Reverse the nested types list, since we want to traverse from the outermost
1757 // to the innermost while checking template-parameter-lists.
1758 std::reverse(NestedTypes.begin(), NestedTypes.end());
1760 // C++0x [temp.expl.spec]p17:
1761 // A member or a member template may be nested within many
1762 // enclosing class templates. In an explicit specialization for
1763 // such a member, the member declaration shall be preceded by a
1764 // template<> for each enclosing class template that is
1765 // explicitly specialized.
1766 bool SawNonEmptyTemplateParameterList = false;
1768 auto CheckExplicitSpecialization = [&](SourceRange Range, bool Recovery) {
1769 if (SawNonEmptyTemplateParameterList) {
1770 Diag(DeclLoc, diag::err_specialize_member_of_template)
1771 << !Recovery << Range;
1773 IsExplicitSpecialization = false;
1780 auto DiagnoseMissingExplicitSpecialization = [&] (SourceRange Range) {
1781 // Check that we can have an explicit specialization here.
1782 if (CheckExplicitSpecialization(Range, true))
1785 // We don't have a template header, but we should.
1786 SourceLocation ExpectedTemplateLoc;
1787 if (!ParamLists.empty())
1788 ExpectedTemplateLoc = ParamLists[0]->getTemplateLoc();
1790 ExpectedTemplateLoc = DeclStartLoc;
1792 Diag(DeclLoc, diag::err_template_spec_needs_header)
1794 << FixItHint::CreateInsertion(ExpectedTemplateLoc, "template<> ");
1798 unsigned ParamIdx = 0;
1799 for (unsigned TypeIdx = 0, NumTypes = NestedTypes.size(); TypeIdx != NumTypes;
1801 T = NestedTypes[TypeIdx];
1803 // Whether we expect a 'template<>' header.
1804 bool NeedEmptyTemplateHeader = false;
1806 // Whether we expect a template header with parameters.
1807 bool NeedNonemptyTemplateHeader = false;
1809 // For a dependent type, the set of template parameters that we
1811 TemplateParameterList *ExpectedTemplateParams = nullptr;
1813 // C++0x [temp.expl.spec]p15:
1814 // A member or a member template may be nested within many enclosing
1815 // class templates. In an explicit specialization for such a member, the
1816 // member declaration shall be preceded by a template<> for each
1817 // enclosing class template that is explicitly specialized.
1818 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
1819 if (ClassTemplatePartialSpecializationDecl *Partial
1820 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
1821 ExpectedTemplateParams = Partial->getTemplateParameters();
1822 NeedNonemptyTemplateHeader = true;
1823 } else if (Record->isDependentType()) {
1824 if (Record->getDescribedClassTemplate()) {
1825 ExpectedTemplateParams = Record->getDescribedClassTemplate()
1826 ->getTemplateParameters();
1827 NeedNonemptyTemplateHeader = true;
1829 } else if (ClassTemplateSpecializationDecl *Spec
1830 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
1831 // C++0x [temp.expl.spec]p4:
1832 // Members of an explicitly specialized class template are defined
1833 // in the same manner as members of normal classes, and not using
1834 // the template<> syntax.
1835 if (Spec->getSpecializationKind() != TSK_ExplicitSpecialization)
1836 NeedEmptyTemplateHeader = true;
1839 } else if (Record->getTemplateSpecializationKind()) {
1840 if (Record->getTemplateSpecializationKind()
1841 != TSK_ExplicitSpecialization &&
1842 TypeIdx == NumTypes - 1)
1843 IsExplicitSpecialization = true;
1847 } else if (const TemplateSpecializationType *TST
1848 = T->getAs<TemplateSpecializationType>()) {
1849 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
1850 ExpectedTemplateParams = Template->getTemplateParameters();
1851 NeedNonemptyTemplateHeader = true;
1853 } else if (T->getAs<DependentTemplateSpecializationType>()) {
1854 // FIXME: We actually could/should check the template arguments here
1855 // against the corresponding template parameter list.
1856 NeedNonemptyTemplateHeader = false;
1859 // C++ [temp.expl.spec]p16:
1860 // In an explicit specialization declaration for a member of a class
1861 // template or a member template that ap- pears in namespace scope, the
1862 // member template and some of its enclosing class templates may remain
1863 // unspecialized, except that the declaration shall not explicitly
1864 // specialize a class member template if its en- closing class templates
1865 // are not explicitly specialized as well.
1866 if (ParamIdx < ParamLists.size()) {
1867 if (ParamLists[ParamIdx]->size() == 0) {
1868 if (CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
1872 SawNonEmptyTemplateParameterList = true;
1875 if (NeedEmptyTemplateHeader) {
1876 // If we're on the last of the types, and we need a 'template<>' header
1877 // here, then it's an explicit specialization.
1878 if (TypeIdx == NumTypes - 1)
1879 IsExplicitSpecialization = true;
1881 if (ParamIdx < ParamLists.size()) {
1882 if (ParamLists[ParamIdx]->size() > 0) {
1883 // The header has template parameters when it shouldn't. Complain.
1884 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
1885 diag::err_template_param_list_matches_nontemplate)
1887 << SourceRange(ParamLists[ParamIdx]->getLAngleLoc(),
1888 ParamLists[ParamIdx]->getRAngleLoc())
1889 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
1894 // Consume this template header.
1900 if (DiagnoseMissingExplicitSpecialization(
1901 getRangeOfTypeInNestedNameSpecifier(Context, T, SS)))
1907 if (NeedNonemptyTemplateHeader) {
1908 // In friend declarations we can have template-ids which don't
1909 // depend on the corresponding template parameter lists. But
1910 // assume that empty parameter lists are supposed to match this
1912 if (IsFriend && T->isDependentType()) {
1913 if (ParamIdx < ParamLists.size() &&
1914 DependsOnTemplateParameters(T, ParamLists[ParamIdx]))
1915 ExpectedTemplateParams = nullptr;
1920 if (ParamIdx < ParamLists.size()) {
1921 // Check the template parameter list, if we can.
1922 if (ExpectedTemplateParams &&
1923 !TemplateParameterListsAreEqual(ParamLists[ParamIdx],
1924 ExpectedTemplateParams,
1925 true, TPL_TemplateMatch))
1929 CheckTemplateParameterList(ParamLists[ParamIdx], nullptr,
1930 TPC_ClassTemplateMember))
1937 Diag(DeclLoc, diag::err_template_spec_needs_template_parameters)
1939 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
1945 // If there were at least as many template-ids as there were template
1946 // parameter lists, then there are no template parameter lists remaining for
1947 // the declaration itself.
1948 if (ParamIdx >= ParamLists.size()) {
1949 if (TemplateId && !IsFriend) {
1950 // We don't have a template header for the declaration itself, but we
1952 IsExplicitSpecialization = true;
1953 DiagnoseMissingExplicitSpecialization(SourceRange(TemplateId->LAngleLoc,
1954 TemplateId->RAngleLoc));
1956 // Fabricate an empty template parameter list for the invented header.
1957 return TemplateParameterList::Create(Context, SourceLocation(),
1958 SourceLocation(), None,
1965 // If there were too many template parameter lists, complain about that now.
1966 if (ParamIdx < ParamLists.size() - 1) {
1967 bool HasAnyExplicitSpecHeader = false;
1968 bool AllExplicitSpecHeaders = true;
1969 for (unsigned I = ParamIdx, E = ParamLists.size() - 1; I != E; ++I) {
1970 if (ParamLists[I]->size() == 0)
1971 HasAnyExplicitSpecHeader = true;
1973 AllExplicitSpecHeaders = false;
1976 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
1977 AllExplicitSpecHeaders ? diag::warn_template_spec_extra_headers
1978 : diag::err_template_spec_extra_headers)
1979 << SourceRange(ParamLists[ParamIdx]->getTemplateLoc(),
1980 ParamLists[ParamLists.size() - 2]->getRAngleLoc());
1982 // If there was a specialization somewhere, such that 'template<>' is
1983 // not required, and there were any 'template<>' headers, note where the
1984 // specialization occurred.
1985 if (ExplicitSpecLoc.isValid() && HasAnyExplicitSpecHeader)
1986 Diag(ExplicitSpecLoc,
1987 diag::note_explicit_template_spec_does_not_need_header)
1988 << NestedTypes.back();
1990 // We have a template parameter list with no corresponding scope, which
1991 // means that the resulting template declaration can't be instantiated
1992 // properly (we'll end up with dependent nodes when we shouldn't).
1993 if (!AllExplicitSpecHeaders)
1997 // C++ [temp.expl.spec]p16:
1998 // In an explicit specialization declaration for a member of a class
1999 // template or a member template that ap- pears in namespace scope, the
2000 // member template and some of its enclosing class templates may remain
2001 // unspecialized, except that the declaration shall not explicitly
2002 // specialize a class member template if its en- closing class templates
2003 // are not explicitly specialized as well.
2004 if (ParamLists.back()->size() == 0 &&
2005 CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
2009 // Return the last template parameter list, which corresponds to the
2010 // entity being declared.
2011 return ParamLists.back();
2014 void Sema::NoteAllFoundTemplates(TemplateName Name) {
2015 if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
2016 Diag(Template->getLocation(), diag::note_template_declared_here)
2017 << (isa<FunctionTemplateDecl>(Template)
2019 : isa<ClassTemplateDecl>(Template)
2021 : isa<VarTemplateDecl>(Template)
2023 : isa<TypeAliasTemplateDecl>(Template) ? 3 : 4)
2024 << Template->getDeclName();
2028 if (OverloadedTemplateStorage *OST = Name.getAsOverloadedTemplate()) {
2029 for (OverloadedTemplateStorage::iterator I = OST->begin(),
2032 Diag((*I)->getLocation(), diag::note_template_declared_here)
2033 << 0 << (*I)->getDeclName();
2040 checkBuiltinTemplateIdType(Sema &SemaRef, BuiltinTemplateDecl *BTD,
2041 const SmallVectorImpl<TemplateArgument> &Converted,
2042 SourceLocation TemplateLoc,
2043 TemplateArgumentListInfo &TemplateArgs) {
2044 ASTContext &Context = SemaRef.getASTContext();
2045 switch (BTD->getBuiltinTemplateKind()) {
2046 case BTK__make_integer_seq: {
2047 // Specializations of __make_integer_seq<S, T, N> are treated like
2048 // S<T, 0, ..., N-1>.
2050 // C++14 [inteseq.intseq]p1:
2051 // T shall be an integer type.
2052 if (!Converted[1].getAsType()->isIntegralType(Context)) {
2053 SemaRef.Diag(TemplateArgs[1].getLocation(),
2054 diag::err_integer_sequence_integral_element_type);
2058 // C++14 [inteseq.make]p1:
2059 // If N is negative the program is ill-formed.
2060 TemplateArgument NumArgsArg = Converted[2];
2061 llvm::APSInt NumArgs = NumArgsArg.getAsIntegral();
2063 SemaRef.Diag(TemplateArgs[2].getLocation(),
2064 diag::err_integer_sequence_negative_length);
2068 QualType ArgTy = NumArgsArg.getIntegralType();
2069 TemplateArgumentListInfo SyntheticTemplateArgs;
2070 // The type argument gets reused as the first template argument in the
2071 // synthetic template argument list.
2072 SyntheticTemplateArgs.addArgument(TemplateArgs[1]);
2073 // Expand N into 0 ... N-1.
2074 for (llvm::APSInt I(NumArgs.getBitWidth(), NumArgs.isUnsigned());
2076 TemplateArgument TA(Context, I, ArgTy);
2077 Expr *E = SemaRef.BuildExpressionFromIntegralTemplateArgument(
2078 TA, TemplateArgs[2].getLocation())
2080 SyntheticTemplateArgs.addArgument(
2081 TemplateArgumentLoc(TemplateArgument(E), E));
2083 // The first template argument will be reused as the template decl that
2084 // our synthetic template arguments will be applied to.
2085 return SemaRef.CheckTemplateIdType(Converted[0].getAsTemplate(),
2086 TemplateLoc, SyntheticTemplateArgs);
2089 case BTK__type_pack_element:
2090 // Specializations of
2091 // __type_pack_element<Index, T_1, ..., T_N>
2092 // are treated like T_Index.
2093 assert(Converted.size() == 2 &&
2094 "__type_pack_element should be given an index and a parameter pack");
2096 // If the Index is out of bounds, the program is ill-formed.
2097 TemplateArgument IndexArg = Converted[0], Ts = Converted[1];
2098 llvm::APSInt Index = IndexArg.getAsIntegral();
2099 assert(Index >= 0 && "the index used with __type_pack_element should be of "
2100 "type std::size_t, and hence be non-negative");
2101 if (Index >= Ts.pack_size()) {
2102 SemaRef.Diag(TemplateArgs[0].getLocation(),
2103 diag::err_type_pack_element_out_of_bounds);
2107 // We simply return the type at index `Index`.
2108 auto Nth = std::next(Ts.pack_begin(), Index.getExtValue());
2109 return Nth->getAsType();
2111 llvm_unreachable("unexpected BuiltinTemplateDecl!");
2114 QualType Sema::CheckTemplateIdType(TemplateName Name,
2115 SourceLocation TemplateLoc,
2116 TemplateArgumentListInfo &TemplateArgs) {
2117 DependentTemplateName *DTN
2118 = Name.getUnderlying().getAsDependentTemplateName();
2119 if (DTN && DTN->isIdentifier())
2120 // When building a template-id where the template-name is dependent,
2121 // assume the template is a type template. Either our assumption is
2122 // correct, or the code is ill-formed and will be diagnosed when the
2123 // dependent name is substituted.
2124 return Context.getDependentTemplateSpecializationType(ETK_None,
2125 DTN->getQualifier(),
2126 DTN->getIdentifier(),
2129 TemplateDecl *Template = Name.getAsTemplateDecl();
2130 if (!Template || isa<FunctionTemplateDecl>(Template) ||
2131 isa<VarTemplateDecl>(Template)) {
2132 // We might have a substituted template template parameter pack. If so,
2133 // build a template specialization type for it.
2134 if (Name.getAsSubstTemplateTemplateParmPack())
2135 return Context.getTemplateSpecializationType(Name, TemplateArgs);
2137 Diag(TemplateLoc, diag::err_template_id_not_a_type)
2139 NoteAllFoundTemplates(Name);
2143 // Check that the template argument list is well-formed for this
2145 SmallVector<TemplateArgument, 4> Converted;
2146 if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs,
2152 bool InstantiationDependent = false;
2153 if (TypeAliasTemplateDecl *AliasTemplate =
2154 dyn_cast<TypeAliasTemplateDecl>(Template)) {
2155 // Find the canonical type for this type alias template specialization.
2156 TypeAliasDecl *Pattern = AliasTemplate->getTemplatedDecl();
2157 if (Pattern->isInvalidDecl())
2160 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
2163 // Only substitute for the innermost template argument list.
2164 MultiLevelTemplateArgumentList TemplateArgLists;
2165 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
2166 unsigned Depth = AliasTemplate->getTemplateParameters()->getDepth();
2167 for (unsigned I = 0; I < Depth; ++I)
2168 TemplateArgLists.addOuterTemplateArguments(None);
2170 LocalInstantiationScope Scope(*this);
2171 InstantiatingTemplate Inst(*this, TemplateLoc, Template);
2172 if (Inst.isInvalid())
2175 CanonType = SubstType(Pattern->getUnderlyingType(),
2176 TemplateArgLists, AliasTemplate->getLocation(),
2177 AliasTemplate->getDeclName());
2178 if (CanonType.isNull())
2180 } else if (Name.isDependent() ||
2181 TemplateSpecializationType::anyDependentTemplateArguments(
2182 TemplateArgs, InstantiationDependent)) {
2183 // This class template specialization is a dependent
2184 // type. Therefore, its canonical type is another class template
2185 // specialization type that contains all of the converted
2186 // arguments in canonical form. This ensures that, e.g., A<T> and
2187 // A<T, T> have identical types when A is declared as:
2189 // template<typename T, typename U = T> struct A;
2190 TemplateName CanonName = Context.getCanonicalTemplateName(Name);
2191 CanonType = Context.getTemplateSpecializationType(CanonName,
2195 // FIXME: CanonType is not actually the canonical type, and unfortunately
2196 // it is a TemplateSpecializationType that we will never use again.
2197 // In the future, we need to teach getTemplateSpecializationType to only
2198 // build the canonical type and return that to us.
2199 CanonType = Context.getCanonicalType(CanonType);
2201 // This might work out to be a current instantiation, in which
2202 // case the canonical type needs to be the InjectedClassNameType.
2204 // TODO: in theory this could be a simple hashtable lookup; most
2205 // changes to CurContext don't change the set of current
2207 if (isa<ClassTemplateDecl>(Template)) {
2208 for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) {
2209 // If we get out to a namespace, we're done.
2210 if (Ctx->isFileContext()) break;
2212 // If this isn't a record, keep looking.
2213 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx);
2214 if (!Record) continue;
2216 // Look for one of the two cases with InjectedClassNameTypes
2217 // and check whether it's the same template.
2218 if (!isa<ClassTemplatePartialSpecializationDecl>(Record) &&
2219 !Record->getDescribedClassTemplate())
2222 // Fetch the injected class name type and check whether its
2223 // injected type is equal to the type we just built.
2224 QualType ICNT = Context.getTypeDeclType(Record);
2225 QualType Injected = cast<InjectedClassNameType>(ICNT)
2226 ->getInjectedSpecializationType();
2228 if (CanonType != Injected->getCanonicalTypeInternal())
2231 // If so, the canonical type of this TST is the injected
2232 // class name type of the record we just found.
2233 assert(ICNT.isCanonical());
2238 } else if (ClassTemplateDecl *ClassTemplate
2239 = dyn_cast<ClassTemplateDecl>(Template)) {
2240 // Find the class template specialization declaration that
2241 // corresponds to these arguments.
2242 void *InsertPos = nullptr;
2243 ClassTemplateSpecializationDecl *Decl
2244 = ClassTemplate->findSpecialization(Converted, InsertPos);
2246 // This is the first time we have referenced this class template
2247 // specialization. Create the canonical declaration and add it to
2248 // the set of specializations.
2249 Decl = ClassTemplateSpecializationDecl::Create(Context,
2250 ClassTemplate->getTemplatedDecl()->getTagKind(),
2251 ClassTemplate->getDeclContext(),
2252 ClassTemplate->getTemplatedDecl()->getLocStart(),
2253 ClassTemplate->getLocation(),
2255 Converted, nullptr);
2256 ClassTemplate->AddSpecialization(Decl, InsertPos);
2257 if (ClassTemplate->isOutOfLine())
2258 Decl->setLexicalDeclContext(ClassTemplate->getLexicalDeclContext());
2261 // Diagnose uses of this specialization.
2262 (void)DiagnoseUseOfDecl(Decl, TemplateLoc);
2264 CanonType = Context.getTypeDeclType(Decl);
2265 assert(isa<RecordType>(CanonType) &&
2266 "type of non-dependent specialization is not a RecordType");
2267 } else if (auto *BTD = dyn_cast<BuiltinTemplateDecl>(Template)) {
2268 CanonType = checkBuiltinTemplateIdType(*this, BTD, Converted, TemplateLoc,
2272 // Build the fully-sugared type for this class template
2273 // specialization, which refers back to the class template
2274 // specialization we created or found.
2275 return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType);
2279 Sema::ActOnTemplateIdType(CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
2280 TemplateTy TemplateD, SourceLocation TemplateLoc,
2281 SourceLocation LAngleLoc,
2282 ASTTemplateArgsPtr TemplateArgsIn,
2283 SourceLocation RAngleLoc,
2284 bool IsCtorOrDtorName) {
2288 TemplateName Template = TemplateD.get();
2290 // Translate the parser's template argument list in our AST format.
2291 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
2292 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
2294 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
2296 = Context.getDependentTemplateSpecializationType(ETK_None,
2297 DTN->getQualifier(),
2298 DTN->getIdentifier(),
2300 // Build type-source information.
2302 DependentTemplateSpecializationTypeLoc SpecTL
2303 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
2304 SpecTL.setElaboratedKeywordLoc(SourceLocation());
2305 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
2306 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2307 SpecTL.setTemplateNameLoc(TemplateLoc);
2308 SpecTL.setLAngleLoc(LAngleLoc);
2309 SpecTL.setRAngleLoc(RAngleLoc);
2310 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
2311 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
2312 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
2315 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
2317 if (Result.isNull())
2320 // Build type-source information.
2322 TemplateSpecializationTypeLoc SpecTL
2323 = TLB.push<TemplateSpecializationTypeLoc>(Result);
2324 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2325 SpecTL.setTemplateNameLoc(TemplateLoc);
2326 SpecTL.setLAngleLoc(LAngleLoc);
2327 SpecTL.setRAngleLoc(RAngleLoc);
2328 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
2329 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
2331 // NOTE: avoid constructing an ElaboratedTypeLoc if this is a
2332 // constructor or destructor name (in such a case, the scope specifier
2333 // will be attached to the enclosing Decl or Expr node).
2334 if (SS.isNotEmpty() && !IsCtorOrDtorName) {
2335 // Create an elaborated-type-specifier containing the nested-name-specifier.
2336 Result = Context.getElaboratedType(ETK_None, SS.getScopeRep(), Result);
2337 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
2338 ElabTL.setElaboratedKeywordLoc(SourceLocation());
2339 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
2342 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
2345 TypeResult Sema::ActOnTagTemplateIdType(TagUseKind TUK,
2346 TypeSpecifierType TagSpec,
2347 SourceLocation TagLoc,
2349 SourceLocation TemplateKWLoc,
2350 TemplateTy TemplateD,
2351 SourceLocation TemplateLoc,
2352 SourceLocation LAngleLoc,
2353 ASTTemplateArgsPtr TemplateArgsIn,
2354 SourceLocation RAngleLoc) {
2355 TemplateName Template = TemplateD.get();
2357 // Translate the parser's template argument list in our AST format.
2358 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
2359 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
2361 // Determine the tag kind
2362 TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
2363 ElaboratedTypeKeyword Keyword
2364 = TypeWithKeyword::getKeywordForTagTypeKind(TagKind);
2366 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
2367 QualType T = Context.getDependentTemplateSpecializationType(Keyword,
2368 DTN->getQualifier(),
2369 DTN->getIdentifier(),
2372 // Build type-source information.
2374 DependentTemplateSpecializationTypeLoc SpecTL
2375 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
2376 SpecTL.setElaboratedKeywordLoc(TagLoc);
2377 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
2378 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2379 SpecTL.setTemplateNameLoc(TemplateLoc);
2380 SpecTL.setLAngleLoc(LAngleLoc);
2381 SpecTL.setRAngleLoc(RAngleLoc);
2382 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
2383 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
2384 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
2387 if (TypeAliasTemplateDecl *TAT =
2388 dyn_cast_or_null<TypeAliasTemplateDecl>(Template.getAsTemplateDecl())) {
2389 // C++0x [dcl.type.elab]p2:
2390 // If the identifier resolves to a typedef-name or the simple-template-id
2391 // resolves to an alias template specialization, the
2392 // elaborated-type-specifier is ill-formed.
2393 Diag(TemplateLoc, diag::err_tag_reference_non_tag) << 4;
2394 Diag(TAT->getLocation(), diag::note_declared_at);
2397 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
2398 if (Result.isNull())
2399 return TypeResult(true);
2401 // Check the tag kind
2402 if (const RecordType *RT = Result->getAs<RecordType>()) {
2403 RecordDecl *D = RT->getDecl();
2405 IdentifierInfo *Id = D->getIdentifier();
2406 assert(Id && "templated class must have an identifier");
2408 if (!isAcceptableTagRedeclaration(D, TagKind, TUK == TUK_Definition,
2410 Diag(TagLoc, diag::err_use_with_wrong_tag)
2412 << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName());
2413 Diag(D->getLocation(), diag::note_previous_use);
2417 // Provide source-location information for the template specialization.
2419 TemplateSpecializationTypeLoc SpecTL
2420 = TLB.push<TemplateSpecializationTypeLoc>(Result);
2421 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
2422 SpecTL.setTemplateNameLoc(TemplateLoc);
2423 SpecTL.setLAngleLoc(LAngleLoc);
2424 SpecTL.setRAngleLoc(RAngleLoc);
2425 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
2426 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
2428 // Construct an elaborated type containing the nested-name-specifier (if any)
2430 Result = Context.getElaboratedType(Keyword, SS.getScopeRep(), Result);
2431 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
2432 ElabTL.setElaboratedKeywordLoc(TagLoc);
2433 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
2434 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
2437 static bool CheckTemplatePartialSpecializationArgs(
2438 Sema &S, SourceLocation NameLoc, TemplateParameterList *TemplateParams,
2439 unsigned ExplicitArgs, SmallVectorImpl<TemplateArgument> &TemplateArgs);
2441 static bool CheckTemplateSpecializationScope(Sema &S, NamedDecl *Specialized,
2442 NamedDecl *PrevDecl,
2444 bool IsPartialSpecialization);
2446 static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D);
2448 static bool isTemplateArgumentTemplateParameter(
2449 const TemplateArgument &Arg, unsigned Depth, unsigned Index) {
2450 switch (Arg.getKind()) {
2451 case TemplateArgument::Null:
2452 case TemplateArgument::NullPtr:
2453 case TemplateArgument::Integral:
2454 case TemplateArgument::Declaration:
2455 case TemplateArgument::Pack:
2456 case TemplateArgument::TemplateExpansion:
2459 case TemplateArgument::Type: {
2460 QualType Type = Arg.getAsType();
2461 const TemplateTypeParmType *TPT =
2462 Arg.getAsType()->getAs<TemplateTypeParmType>();
2463 return TPT && !Type.hasQualifiers() &&
2464 TPT->getDepth() == Depth && TPT->getIndex() == Index;
2467 case TemplateArgument::Expression: {
2468 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg.getAsExpr());
2469 if (!DRE || !DRE->getDecl())
2471 const NonTypeTemplateParmDecl *NTTP =
2472 dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl());
2473 return NTTP && NTTP->getDepth() == Depth && NTTP->getIndex() == Index;
2476 case TemplateArgument::Template:
2477 const TemplateTemplateParmDecl *TTP =
2478 dyn_cast_or_null<TemplateTemplateParmDecl>(
2479 Arg.getAsTemplateOrTemplatePattern().getAsTemplateDecl());
2480 return TTP && TTP->getDepth() == Depth && TTP->getIndex() == Index;
2482 llvm_unreachable("unexpected kind of template argument");
2485 static bool isSameAsPrimaryTemplate(TemplateParameterList *Params,
2486 ArrayRef<TemplateArgument> Args) {
2487 if (Params->size() != Args.size())
2490 unsigned Depth = Params->getDepth();
2492 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
2493 TemplateArgument Arg = Args[I];
2495 // If the parameter is a pack expansion, the argument must be a pack
2496 // whose only element is a pack expansion.
2497 if (Params->getParam(I)->isParameterPack()) {
2498 if (Arg.getKind() != TemplateArgument::Pack || Arg.pack_size() != 1 ||
2499 !Arg.pack_begin()->isPackExpansion())
2501 Arg = Arg.pack_begin()->getPackExpansionPattern();
2504 if (!isTemplateArgumentTemplateParameter(Arg, Depth, I))
2511 /// Convert the parser's template argument list representation into our form.
2512 static TemplateArgumentListInfo
2513 makeTemplateArgumentListInfo(Sema &S, TemplateIdAnnotation &TemplateId) {
2514 TemplateArgumentListInfo TemplateArgs(TemplateId.LAngleLoc,
2515 TemplateId.RAngleLoc);
2516 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId.getTemplateArgs(),
2517 TemplateId.NumArgs);
2518 S.translateTemplateArguments(TemplateArgsPtr, TemplateArgs);
2519 return TemplateArgs;
2522 DeclResult Sema::ActOnVarTemplateSpecialization(
2523 Scope *S, Declarator &D, TypeSourceInfo *DI, SourceLocation TemplateKWLoc,
2524 TemplateParameterList *TemplateParams, StorageClass SC,
2525 bool IsPartialSpecialization) {
2526 // D must be variable template id.
2527 assert(D.getName().getKind() == UnqualifiedId::IK_TemplateId &&
2528 "Variable template specialization is declared with a template it.");
2530 TemplateIdAnnotation *TemplateId = D.getName().TemplateId;
2531 TemplateArgumentListInfo TemplateArgs =
2532 makeTemplateArgumentListInfo(*this, *TemplateId);
2533 SourceLocation TemplateNameLoc = D.getIdentifierLoc();
2534 SourceLocation LAngleLoc = TemplateId->LAngleLoc;
2535 SourceLocation RAngleLoc = TemplateId->RAngleLoc;
2537 TemplateName Name = TemplateId->Template.get();
2539 // The template-id must name a variable template.
2540 VarTemplateDecl *VarTemplate =
2541 dyn_cast_or_null<VarTemplateDecl>(Name.getAsTemplateDecl());
2543 NamedDecl *FnTemplate;
2544 if (auto *OTS = Name.getAsOverloadedTemplate())
2545 FnTemplate = *OTS->begin();
2547 FnTemplate = dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl());
2549 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template_but_method)
2550 << FnTemplate->getDeclName();
2551 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template)
2552 << IsPartialSpecialization;
2555 // Check for unexpanded parameter packs in any of the template arguments.
2556 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2557 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
2558 UPPC_PartialSpecialization))
2561 // Check that the template argument list is well-formed for this
2563 SmallVector<TemplateArgument, 4> Converted;
2564 if (CheckTemplateArgumentList(VarTemplate, TemplateNameLoc, TemplateArgs,
2568 // Find the variable template (partial) specialization declaration that
2569 // corresponds to these arguments.
2570 if (IsPartialSpecialization) {
2571 if (CheckTemplatePartialSpecializationArgs(
2572 *this, TemplateNameLoc, VarTemplate->getTemplateParameters(),
2573 TemplateArgs.size(), Converted))
2576 bool InstantiationDependent;
2577 if (!Name.isDependent() &&
2578 !TemplateSpecializationType::anyDependentTemplateArguments(
2579 TemplateArgs.getArgumentArray(), TemplateArgs.size(),
2580 InstantiationDependent)) {
2581 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
2582 << VarTemplate->getDeclName();
2583 IsPartialSpecialization = false;
2586 if (isSameAsPrimaryTemplate(VarTemplate->getTemplateParameters(),
2588 // C++ [temp.class.spec]p9b3:
2590 // -- The argument list of the specialization shall not be identical
2591 // to the implicit argument list of the primary template.
2592 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
2593 << /*variable template*/ 1
2594 << /*is definition*/(SC != SC_Extern && !CurContext->isRecord())
2595 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
2596 // FIXME: Recover from this by treating the declaration as a redeclaration
2597 // of the primary template.
2602 void *InsertPos = nullptr;
2603 VarTemplateSpecializationDecl *PrevDecl = nullptr;
2605 if (IsPartialSpecialization)
2606 // FIXME: Template parameter list matters too
2607 PrevDecl = VarTemplate->findPartialSpecialization(Converted, InsertPos);
2609 PrevDecl = VarTemplate->findSpecialization(Converted, InsertPos);
2611 VarTemplateSpecializationDecl *Specialization = nullptr;
2613 // Check whether we can declare a variable template specialization in
2614 // the current scope.
2615 if (CheckTemplateSpecializationScope(*this, VarTemplate, PrevDecl,
2617 IsPartialSpecialization))
2620 if (PrevDecl && PrevDecl->getSpecializationKind() == TSK_Undeclared) {
2621 // Since the only prior variable template specialization with these
2622 // arguments was referenced but not declared, reuse that
2623 // declaration node as our own, updating its source location and
2624 // the list of outer template parameters to reflect our new declaration.
2625 Specialization = PrevDecl;
2626 Specialization->setLocation(TemplateNameLoc);
2628 } else if (IsPartialSpecialization) {
2629 // Create a new class template partial specialization declaration node.
2630 VarTemplatePartialSpecializationDecl *PrevPartial =
2631 cast_or_null<VarTemplatePartialSpecializationDecl>(PrevDecl);
2632 VarTemplatePartialSpecializationDecl *Partial =
2633 VarTemplatePartialSpecializationDecl::Create(
2634 Context, VarTemplate->getDeclContext(), TemplateKWLoc,
2635 TemplateNameLoc, TemplateParams, VarTemplate, DI->getType(), DI, SC,
2636 Converted, TemplateArgs);
2639 VarTemplate->AddPartialSpecialization(Partial, InsertPos);
2640 Specialization = Partial;
2642 // If we are providing an explicit specialization of a member variable
2643 // template specialization, make a note of that.
2644 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
2645 PrevPartial->setMemberSpecialization();
2647 // Check that all of the template parameters of the variable template
2648 // partial specialization are deducible from the template
2649 // arguments. If not, this variable template partial specialization
2650 // will never be used.
2651 llvm::SmallBitVector DeducibleParams(TemplateParams->size());
2652 MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
2653 TemplateParams->getDepth(), DeducibleParams);
2655 if (!DeducibleParams.all()) {
2656 unsigned NumNonDeducible =
2657 DeducibleParams.size() - DeducibleParams.count();
2658 Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible)
2659 << /*variable template*/ 1 << (NumNonDeducible > 1)
2660 << SourceRange(TemplateNameLoc, RAngleLoc);
2661 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) {
2662 if (!DeducibleParams[I]) {
2663 NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I));
2664 if (Param->getDeclName())
2665 Diag(Param->getLocation(), diag::note_partial_spec_unused_parameter)
2666 << Param->getDeclName();
2668 Diag(Param->getLocation(), diag::note_partial_spec_unused_parameter)
2674 // Create a new class template specialization declaration node for
2675 // this explicit specialization or friend declaration.
2676 Specialization = VarTemplateSpecializationDecl::Create(
2677 Context, VarTemplate->getDeclContext(), TemplateKWLoc, TemplateNameLoc,
2678 VarTemplate, DI->getType(), DI, SC, Converted);
2679 Specialization->setTemplateArgsInfo(TemplateArgs);
2682 VarTemplate->AddSpecialization(Specialization, InsertPos);
2685 // C++ [temp.expl.spec]p6:
2686 // If a template, a member template or the member of a class template is
2687 // explicitly specialized then that specialization shall be declared
2688 // before the first use of that specialization that would cause an implicit
2689 // instantiation to take place, in every translation unit in which such a
2690 // use occurs; no diagnostic is required.
2691 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
2693 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
2694 // Is there any previous explicit specialization declaration?
2695 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
2702 SourceRange Range(TemplateNameLoc, RAngleLoc);
2703 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
2706 Diag(PrevDecl->getPointOfInstantiation(),
2707 diag::note_instantiation_required_here)
2708 << (PrevDecl->getTemplateSpecializationKind() !=
2709 TSK_ImplicitInstantiation);
2714 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
2715 Specialization->setLexicalDeclContext(CurContext);
2717 // Add the specialization into its lexical context, so that it can
2718 // be seen when iterating through the list of declarations in that
2719 // context. However, specializations are not found by name lookup.
2720 CurContext->addDecl(Specialization);
2722 // Note that this is an explicit specialization.
2723 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
2726 // Check that this isn't a redefinition of this specialization,
2727 // merging with previous declarations.
2728 LookupResult PrevSpec(*this, GetNameForDeclarator(D), LookupOrdinaryName,
2730 PrevSpec.addDecl(PrevDecl);
2731 D.setRedeclaration(CheckVariableDeclaration(Specialization, PrevSpec));
2732 } else if (Specialization->isStaticDataMember() &&
2733 Specialization->isOutOfLine()) {
2734 Specialization->setAccess(VarTemplate->getAccess());
2737 // Link instantiations of static data members back to the template from
2738 // which they were instantiated.
2739 if (Specialization->isStaticDataMember())
2740 Specialization->setInstantiationOfStaticDataMember(
2741 VarTemplate->getTemplatedDecl(),
2742 Specialization->getSpecializationKind());
2744 return Specialization;
2748 /// \brief A partial specialization whose template arguments have matched
2749 /// a given template-id.
2750 struct PartialSpecMatchResult {
2751 VarTemplatePartialSpecializationDecl *Partial;
2752 TemplateArgumentList *Args;
2754 } // end anonymous namespace
2757 Sema::CheckVarTemplateId(VarTemplateDecl *Template, SourceLocation TemplateLoc,
2758 SourceLocation TemplateNameLoc,
2759 const TemplateArgumentListInfo &TemplateArgs) {
2760 assert(Template && "A variable template id without template?");
2762 // Check that the template argument list is well-formed for this template.
2763 SmallVector<TemplateArgument, 4> Converted;
2764 if (CheckTemplateArgumentList(
2765 Template, TemplateNameLoc,
2766 const_cast<TemplateArgumentListInfo &>(TemplateArgs), false,
2770 // Find the variable template specialization declaration that
2771 // corresponds to these arguments.
2772 void *InsertPos = nullptr;
2773 if (VarTemplateSpecializationDecl *Spec = Template->findSpecialization(
2774 Converted, InsertPos)) {
2775 checkSpecializationVisibility(TemplateNameLoc, Spec);
2776 // If we already have a variable template specialization, return it.
2780 // This is the first time we have referenced this variable template
2781 // specialization. Create the canonical declaration and add it to
2782 // the set of specializations, based on the closest partial specialization
2783 // that it represents. That is,
2784 VarDecl *InstantiationPattern = Template->getTemplatedDecl();
2785 TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack,
2787 TemplateArgumentList *InstantiationArgs = &TemplateArgList;
2788 bool AmbiguousPartialSpec = false;
2789 typedef PartialSpecMatchResult MatchResult;
2790 SmallVector<MatchResult, 4> Matched;
2791 SourceLocation PointOfInstantiation = TemplateNameLoc;
2792 TemplateSpecCandidateSet FailedCandidates(PointOfInstantiation,
2793 /*ForTakingAddress=*/false);
2795 // 1. Attempt to find the closest partial specialization that this
2796 // specializes, if any.
2797 // If any of the template arguments is dependent, then this is probably
2798 // a placeholder for an incomplete declarative context; which must be
2799 // complete by instantiation time. Thus, do not search through the partial
2800 // specializations yet.
2801 // TODO: Unify with InstantiateClassTemplateSpecialization()?
2802 // Perhaps better after unification of DeduceTemplateArguments() and
2803 // getMoreSpecializedPartialSpecialization().
2804 bool InstantiationDependent = false;
2805 if (!TemplateSpecializationType::anyDependentTemplateArguments(
2806 TemplateArgs, InstantiationDependent)) {
2808 SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
2809 Template->getPartialSpecializations(PartialSpecs);
2811 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) {
2812 VarTemplatePartialSpecializationDecl *Partial = PartialSpecs[I];
2813 TemplateDeductionInfo Info(FailedCandidates.getLocation());
2815 if (TemplateDeductionResult Result =
2816 DeduceTemplateArguments(Partial, TemplateArgList, Info)) {
2817 // Store the failed-deduction information for use in diagnostics, later.
2818 // TODO: Actually use the failed-deduction info?
2819 FailedCandidates.addCandidate().set(
2820 DeclAccessPair::make(Template, AS_public), Partial,
2821 MakeDeductionFailureInfo(Context, Result, Info));
2824 Matched.push_back(PartialSpecMatchResult());
2825 Matched.back().Partial = Partial;
2826 Matched.back().Args = Info.take();
2830 if (Matched.size() >= 1) {
2831 SmallVector<MatchResult, 4>::iterator Best = Matched.begin();
2832 if (Matched.size() == 1) {
2833 // -- If exactly one matching specialization is found, the
2834 // instantiation is generated from that specialization.
2835 // We don't need to do anything for this.
2837 // -- If more than one matching specialization is found, the
2838 // partial order rules (14.5.4.2) are used to determine
2839 // whether one of the specializations is more specialized
2840 // than the others. If none of the specializations is more
2841 // specialized than all of the other matching
2842 // specializations, then the use of the variable template is
2843 // ambiguous and the program is ill-formed.
2844 for (SmallVector<MatchResult, 4>::iterator P = Best + 1,
2845 PEnd = Matched.end();
2847 if (getMoreSpecializedPartialSpecialization(P->Partial, Best->Partial,
2848 PointOfInstantiation) ==
2853 // Determine if the best partial specialization is more specialized than
2855 for (SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
2856 PEnd = Matched.end();
2858 if (P != Best && getMoreSpecializedPartialSpecialization(
2859 P->Partial, Best->Partial,
2860 PointOfInstantiation) != Best->Partial) {
2861 AmbiguousPartialSpec = true;
2867 // Instantiate using the best variable template partial specialization.
2868 InstantiationPattern = Best->Partial;
2869 InstantiationArgs = Best->Args;
2871 // -- If no match is found, the instantiation is generated
2872 // from the primary template.
2873 // InstantiationPattern = Template->getTemplatedDecl();
2877 // 2. Create the canonical declaration.
2878 // Note that we do not instantiate a definition until we see an odr-use
2879 // in DoMarkVarDeclReferenced().
2880 // FIXME: LateAttrs et al.?
2881 VarTemplateSpecializationDecl *Decl = BuildVarTemplateInstantiation(
2882 Template, InstantiationPattern, *InstantiationArgs, TemplateArgs,
2883 Converted, TemplateNameLoc, InsertPos /*, LateAttrs, StartingScope*/);
2887 if (AmbiguousPartialSpec) {
2888 // Partial ordering did not produce a clear winner. Complain.
2889 Decl->setInvalidDecl();
2890 Diag(PointOfInstantiation, diag::err_partial_spec_ordering_ambiguous)
2893 // Print the matching partial specializations.
2894 for (SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
2895 PEnd = Matched.end();
2897 Diag(P->Partial->getLocation(), diag::note_partial_spec_match)
2898 << getTemplateArgumentBindingsText(
2899 P->Partial->getTemplateParameters(), *P->Args);
2903 if (VarTemplatePartialSpecializationDecl *D =
2904 dyn_cast<VarTemplatePartialSpecializationDecl>(InstantiationPattern))
2905 Decl->setInstantiationOf(D, InstantiationArgs);
2907 checkSpecializationVisibility(TemplateNameLoc, Decl);
2909 assert(Decl && "No variable template specialization?");
2914 Sema::CheckVarTemplateId(const CXXScopeSpec &SS,
2915 const DeclarationNameInfo &NameInfo,
2916 VarTemplateDecl *Template, SourceLocation TemplateLoc,
2917 const TemplateArgumentListInfo *TemplateArgs) {
2919 DeclResult Decl = CheckVarTemplateId(Template, TemplateLoc, NameInfo.getLoc(),
2921 if (Decl.isInvalid())
2924 VarDecl *Var = cast<VarDecl>(Decl.get());
2925 if (!Var->getTemplateSpecializationKind())
2926 Var->setTemplateSpecializationKind(TSK_ImplicitInstantiation,
2929 // Build an ordinary singleton decl ref.
2930 return BuildDeclarationNameExpr(SS, NameInfo, Var,
2931 /*FoundD=*/nullptr, TemplateArgs);
2934 ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS,
2935 SourceLocation TemplateKWLoc,
2938 const TemplateArgumentListInfo *TemplateArgs) {
2939 // FIXME: Can we do any checking at this point? I guess we could check the
2940 // template arguments that we have against the template name, if the template
2941 // name refers to a single template. That's not a terribly common case,
2943 // foo<int> could identify a single function unambiguously
2944 // This approach does NOT work, since f<int>(1);
2945 // gets resolved prior to resorting to overload resolution
2946 // i.e., template<class T> void f(double);
2947 // vs template<class T, class U> void f(U);
2949 // These should be filtered out by our callers.
2950 assert(!R.empty() && "empty lookup results when building templateid");
2951 assert(!R.isAmbiguous() && "ambiguous lookup when building templateid");
2953 // In C++1y, check variable template ids.
2954 bool InstantiationDependent;
2955 if (R.getAsSingle<VarTemplateDecl>() &&
2956 !TemplateSpecializationType::anyDependentTemplateArguments(
2957 *TemplateArgs, InstantiationDependent)) {
2958 return CheckVarTemplateId(SS, R.getLookupNameInfo(),
2959 R.getAsSingle<VarTemplateDecl>(),
2960 TemplateKWLoc, TemplateArgs);
2963 // We don't want lookup warnings at this point.
2964 R.suppressDiagnostics();
2966 UnresolvedLookupExpr *ULE
2967 = UnresolvedLookupExpr::Create(Context, R.getNamingClass(),
2968 SS.getWithLocInContext(Context),
2970 R.getLookupNameInfo(),
2971 RequiresADL, TemplateArgs,
2972 R.begin(), R.end());
2977 // We actually only call this from template instantiation.
2979 Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS,
2980 SourceLocation TemplateKWLoc,
2981 const DeclarationNameInfo &NameInfo,
2982 const TemplateArgumentListInfo *TemplateArgs) {
2984 assert(TemplateArgs || TemplateKWLoc.isValid());
2986 if (!(DC = computeDeclContext(SS, false)) ||
2987 DC->isDependentContext() ||
2988 RequireCompleteDeclContext(SS, DC))
2989 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
2991 bool MemberOfUnknownSpecialization;
2992 LookupResult R(*this, NameInfo, LookupOrdinaryName);
2993 LookupTemplateName(R, (Scope*)nullptr, SS, QualType(), /*Entering*/ false,
2994 MemberOfUnknownSpecialization);
2996 if (R.isAmbiguous())
3000 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_non_template)
3001 << NameInfo.getName() << SS.getRange();
3005 if (ClassTemplateDecl *Temp = R.getAsSingle<ClassTemplateDecl>()) {
3006 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_class_template)
3008 << NameInfo.getName().getAsString() << SS.getRange();
3009 Diag(Temp->getLocation(), diag::note_referenced_class_template);
3013 return BuildTemplateIdExpr(SS, TemplateKWLoc, R, /*ADL*/ false, TemplateArgs);
3016 /// \brief Form a dependent template name.
3018 /// This action forms a dependent template name given the template
3019 /// name and its (presumably dependent) scope specifier. For
3020 /// example, given "MetaFun::template apply", the scope specifier \p
3021 /// SS will be "MetaFun::", \p TemplateKWLoc contains the location
3022 /// of the "template" keyword, and "apply" is the \p Name.
3023 TemplateNameKind Sema::ActOnDependentTemplateName(Scope *S,
3025 SourceLocation TemplateKWLoc,
3026 UnqualifiedId &Name,
3027 ParsedType ObjectType,
3028 bool EnteringContext,
3029 TemplateTy &Result) {
3030 if (TemplateKWLoc.isValid() && S && !S->getTemplateParamParent())
3032 getLangOpts().CPlusPlus11 ?
3033 diag::warn_cxx98_compat_template_outside_of_template :
3034 diag::ext_template_outside_of_template)
3035 << FixItHint::CreateRemoval(TemplateKWLoc);
3037 DeclContext *LookupCtx = nullptr;
3039 LookupCtx = computeDeclContext(SS, EnteringContext);
3040 if (!LookupCtx && ObjectType)
3041 LookupCtx = computeDeclContext(ObjectType.get());
3043 // C++0x [temp.names]p5:
3044 // If a name prefixed by the keyword template is not the name of
3045 // a template, the program is ill-formed. [Note: the keyword
3046 // template may not be applied to non-template members of class
3047 // templates. -end note ] [ Note: as is the case with the
3048 // typename prefix, the template prefix is allowed in cases
3049 // where it is not strictly necessary; i.e., when the
3050 // nested-name-specifier or the expression on the left of the ->
3051 // or . is not dependent on a template-parameter, or the use
3052 // does not appear in the scope of a template. -end note]
3054 // Note: C++03 was more strict here, because it banned the use of
3055 // the "template" keyword prior to a template-name that was not a
3056 // dependent name. C++ DR468 relaxed this requirement (the
3057 // "template" keyword is now permitted). We follow the C++0x
3058 // rules, even in C++03 mode with a warning, retroactively applying the DR.
3059 bool MemberOfUnknownSpecialization;
3060 TemplateNameKind TNK = isTemplateName(S, SS, TemplateKWLoc.isValid(), Name,
3061 ObjectType, EnteringContext, Result,
3062 MemberOfUnknownSpecialization);
3063 if (TNK == TNK_Non_template && LookupCtx->isDependentContext() &&
3064 isa<CXXRecordDecl>(LookupCtx) &&
3065 (!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() ||
3066 cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases())) {
3067 // This is a dependent template. Handle it below.
3068 } else if (TNK == TNK_Non_template) {
3069 Diag(Name.getLocStart(),
3070 diag::err_template_kw_refers_to_non_template)
3071 << GetNameFromUnqualifiedId(Name).getName()
3072 << Name.getSourceRange()
3074 return TNK_Non_template;
3076 // We found something; return it.
3081 NestedNameSpecifier *Qualifier = SS.getScopeRep();
3083 switch (Name.getKind()) {
3084 case UnqualifiedId::IK_Identifier:
3085 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier,
3087 return TNK_Dependent_template_name;
3089 case UnqualifiedId::IK_OperatorFunctionId:
3090 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier,
3091 Name.OperatorFunctionId.Operator));
3092 return TNK_Function_template;
3094 case UnqualifiedId::IK_LiteralOperatorId:
3095 llvm_unreachable("literal operator id cannot have a dependent scope");
3101 Diag(Name.getLocStart(),
3102 diag::err_template_kw_refers_to_non_template)
3103 << GetNameFromUnqualifiedId(Name).getName()
3104 << Name.getSourceRange()
3106 return TNK_Non_template;
3109 bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param,
3110 TemplateArgumentLoc &AL,
3111 SmallVectorImpl<TemplateArgument> &Converted) {
3112 const TemplateArgument &Arg = AL.getArgument();
3114 TypeSourceInfo *TSI = nullptr;
3116 // Check template type parameter.
3117 switch(Arg.getKind()) {
3118 case TemplateArgument::Type:
3119 // C++ [temp.arg.type]p1:
3120 // A template-argument for a template-parameter which is a
3121 // type shall be a type-id.
3122 ArgType = Arg.getAsType();
3123 TSI = AL.getTypeSourceInfo();
3125 case TemplateArgument::Template: {
3126 // We have a template type parameter but the template argument
3127 // is a template without any arguments.
3128 SourceRange SR = AL.getSourceRange();
3129 TemplateName Name = Arg.getAsTemplate();
3130 Diag(SR.getBegin(), diag::err_template_missing_args)
3132 if (TemplateDecl *Decl = Name.getAsTemplateDecl())
3133 Diag(Decl->getLocation(), diag::note_template_decl_here);
3137 case TemplateArgument::Expression: {
3138 // We have a template type parameter but the template argument is an
3139 // expression; see if maybe it is missing the "typename" keyword.
3141 DeclarationNameInfo NameInfo;
3143 if (DeclRefExpr *ArgExpr = dyn_cast<DeclRefExpr>(Arg.getAsExpr())) {
3144 SS.Adopt(ArgExpr->getQualifierLoc());
3145 NameInfo = ArgExpr->getNameInfo();
3146 } else if (DependentScopeDeclRefExpr *ArgExpr =
3147 dyn_cast<DependentScopeDeclRefExpr>(Arg.getAsExpr())) {
3148 SS.Adopt(ArgExpr->getQualifierLoc());
3149 NameInfo = ArgExpr->getNameInfo();
3150 } else if (CXXDependentScopeMemberExpr *ArgExpr =
3151 dyn_cast<CXXDependentScopeMemberExpr>(Arg.getAsExpr())) {
3152 if (ArgExpr->isImplicitAccess()) {
3153 SS.Adopt(ArgExpr->getQualifierLoc());
3154 NameInfo = ArgExpr->getMemberNameInfo();
3158 if (auto *II = NameInfo.getName().getAsIdentifierInfo()) {
3159 LookupResult Result(*this, NameInfo, LookupOrdinaryName);
3160 LookupParsedName(Result, CurScope, &SS);
3162 if (Result.getAsSingle<TypeDecl>() ||
3163 Result.getResultKind() ==
3164 LookupResult::NotFoundInCurrentInstantiation) {
3165 // Suggest that the user add 'typename' before the NNS.
3166 SourceLocation Loc = AL.getSourceRange().getBegin();
3167 Diag(Loc, getLangOpts().MSVCCompat
3168 ? diag::ext_ms_template_type_arg_missing_typename
3169 : diag::err_template_arg_must_be_type_suggest)
3170 << FixItHint::CreateInsertion(Loc, "typename ");
3171 Diag(Param->getLocation(), diag::note_template_param_here);
3173 // Recover by synthesizing a type using the location information that we
3176 Context.getDependentNameType(ETK_Typename, SS.getScopeRep(), II);
3178 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(ArgType);
3179 TL.setElaboratedKeywordLoc(SourceLocation(/*synthesized*/));
3180 TL.setQualifierLoc(SS.getWithLocInContext(Context));
3181 TL.setNameLoc(NameInfo.getLoc());
3182 TSI = TLB.getTypeSourceInfo(Context, ArgType);
3184 // Overwrite our input TemplateArgumentLoc so that we can recover
3186 AL = TemplateArgumentLoc(TemplateArgument(ArgType),
3187 TemplateArgumentLocInfo(TSI));
3195 // We have a template type parameter but the template argument
3197 SourceRange SR = AL.getSourceRange();
3198 Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR;
3199 Diag(Param->getLocation(), diag::note_template_param_here);
3205 if (CheckTemplateArgument(Param, TSI))
3208 // Add the converted template type argument.
3209 ArgType = Context.getCanonicalType(ArgType);
3212 // If an explicitly-specified template argument type is a lifetime type
3213 // with no lifetime qualifier, the __strong lifetime qualifier is inferred.
3214 if (getLangOpts().ObjCAutoRefCount &&
3215 ArgType->isObjCLifetimeType() &&
3216 !ArgType.getObjCLifetime()) {
3218 Qs.setObjCLifetime(Qualifiers::OCL_Strong);
3219 ArgType = Context.getQualifiedType(ArgType, Qs);
3222 Converted.push_back(TemplateArgument(ArgType));
3226 /// \brief Substitute template arguments into the default template argument for
3227 /// the given template type parameter.
3229 /// \param SemaRef the semantic analysis object for which we are performing
3230 /// the substitution.
3232 /// \param Template the template that we are synthesizing template arguments
3235 /// \param TemplateLoc the location of the template name that started the
3236 /// template-id we are checking.
3238 /// \param RAngleLoc the location of the right angle bracket ('>') that
3239 /// terminates the template-id.
3241 /// \param Param the template template parameter whose default we are
3242 /// substituting into.
3244 /// \param Converted the list of template arguments provided for template
3245 /// parameters that precede \p Param in the template parameter list.
3246 /// \returns the substituted template argument, or NULL if an error occurred.
3247 static TypeSourceInfo *
3248 SubstDefaultTemplateArgument(Sema &SemaRef,
3249 TemplateDecl *Template,
3250 SourceLocation TemplateLoc,
3251 SourceLocation RAngleLoc,
3252 TemplateTypeParmDecl *Param,
3253 SmallVectorImpl<TemplateArgument> &Converted) {
3254 TypeSourceInfo *ArgType = Param->getDefaultArgumentInfo();
3256 // If the argument type is dependent, instantiate it now based
3257 // on the previously-computed template arguments.
3258 if (ArgType->getType()->isDependentType()) {
3259 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
3260 Template, Converted,
3261 SourceRange(TemplateLoc, RAngleLoc));
3262 if (Inst.isInvalid())
3265 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
3267 // Only substitute for the innermost template argument list.
3268 MultiLevelTemplateArgumentList TemplateArgLists;
3269 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3270 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3271 TemplateArgLists.addOuterTemplateArguments(None);
3273 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
3275 SemaRef.SubstType(ArgType, TemplateArgLists,
3276 Param->getDefaultArgumentLoc(), Param->getDeclName());
3282 /// \brief Substitute template arguments into the default template argument for
3283 /// the given non-type template parameter.
3285 /// \param SemaRef the semantic analysis object for which we are performing
3286 /// the substitution.
3288 /// \param Template the template that we are synthesizing template arguments
3291 /// \param TemplateLoc the location of the template name that started the
3292 /// template-id we are checking.
3294 /// \param RAngleLoc the location of the right angle bracket ('>') that
3295 /// terminates the template-id.
3297 /// \param Param the non-type template parameter whose default we are
3298 /// substituting into.
3300 /// \param Converted the list of template arguments provided for template
3301 /// parameters that precede \p Param in the template parameter list.
3303 /// \returns the substituted template argument, or NULL if an error occurred.
3305 SubstDefaultTemplateArgument(Sema &SemaRef,
3306 TemplateDecl *Template,
3307 SourceLocation TemplateLoc,
3308 SourceLocation RAngleLoc,
3309 NonTypeTemplateParmDecl *Param,
3310 SmallVectorImpl<TemplateArgument> &Converted) {
3311 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
3312 Template, Converted,
3313 SourceRange(TemplateLoc, RAngleLoc));
3314 if (Inst.isInvalid())
3317 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
3319 // Only substitute for the innermost template argument list.
3320 MultiLevelTemplateArgumentList TemplateArgLists;
3321 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3322 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3323 TemplateArgLists.addOuterTemplateArguments(None);
3325 EnterExpressionEvaluationContext ConstantEvaluated(SemaRef,
3326 Sema::ConstantEvaluated);
3327 return SemaRef.SubstExpr(Param->getDefaultArgument(), TemplateArgLists);
3330 /// \brief Substitute template arguments into the default template argument for
3331 /// the given template template parameter.
3333 /// \param SemaRef the semantic analysis object for which we are performing
3334 /// the substitution.
3336 /// \param Template the template that we are synthesizing template arguments
3339 /// \param TemplateLoc the location of the template name that started the
3340 /// template-id we are checking.
3342 /// \param RAngleLoc the location of the right angle bracket ('>') that
3343 /// terminates the template-id.
3345 /// \param Param the template template parameter whose default we are
3346 /// substituting into.
3348 /// \param Converted the list of template arguments provided for template
3349 /// parameters that precede \p Param in the template parameter list.
3351 /// \param QualifierLoc Will be set to the nested-name-specifier (with
3352 /// source-location information) that precedes the template name.
3354 /// \returns the substituted template argument, or NULL if an error occurred.
3356 SubstDefaultTemplateArgument(Sema &SemaRef,
3357 TemplateDecl *Template,
3358 SourceLocation TemplateLoc,
3359 SourceLocation RAngleLoc,
3360 TemplateTemplateParmDecl *Param,
3361 SmallVectorImpl<TemplateArgument> &Converted,
3362 NestedNameSpecifierLoc &QualifierLoc) {
3363 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, Template, Converted,
3364 SourceRange(TemplateLoc, RAngleLoc));
3365 if (Inst.isInvalid())
3366 return TemplateName();
3368 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
3370 // Only substitute for the innermost template argument list.
3371 MultiLevelTemplateArgumentList TemplateArgLists;
3372 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
3373 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
3374 TemplateArgLists.addOuterTemplateArguments(None);
3376 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
3377 // Substitute into the nested-name-specifier first,
3378 QualifierLoc = Param->getDefaultArgument().getTemplateQualifierLoc();
3381 SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgLists);
3383 return TemplateName();
3386 return SemaRef.SubstTemplateName(
3388 Param->getDefaultArgument().getArgument().getAsTemplate(),
3389 Param->getDefaultArgument().getTemplateNameLoc(),
3393 /// \brief If the given template parameter has a default template
3394 /// argument, substitute into that default template argument and
3395 /// return the corresponding template argument.
3397 Sema::SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template,
3398 SourceLocation TemplateLoc,
3399 SourceLocation RAngleLoc,
3401 SmallVectorImpl<TemplateArgument>
3403 bool &HasDefaultArg) {
3404 HasDefaultArg = false;
3406 if (TemplateTypeParmDecl *TypeParm = dyn_cast<TemplateTypeParmDecl>(Param)) {
3407 if (!hasVisibleDefaultArgument(TypeParm))
3408 return TemplateArgumentLoc();
3410 HasDefaultArg = true;
3411 TypeSourceInfo *DI = SubstDefaultTemplateArgument(*this, Template,
3417 return TemplateArgumentLoc(TemplateArgument(DI->getType()), DI);
3419 return TemplateArgumentLoc();
3422 if (NonTypeTemplateParmDecl *NonTypeParm
3423 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3424 if (!hasVisibleDefaultArgument(NonTypeParm))
3425 return TemplateArgumentLoc();
3427 HasDefaultArg = true;
3428 ExprResult Arg = SubstDefaultTemplateArgument(*this, Template,
3433 if (Arg.isInvalid())
3434 return TemplateArgumentLoc();
3436 Expr *ArgE = Arg.getAs<Expr>();
3437 return TemplateArgumentLoc(TemplateArgument(ArgE), ArgE);
3440 TemplateTemplateParmDecl *TempTempParm
3441 = cast<TemplateTemplateParmDecl>(Param);
3442 if (!hasVisibleDefaultArgument(TempTempParm))
3443 return TemplateArgumentLoc();
3445 HasDefaultArg = true;
3446 NestedNameSpecifierLoc QualifierLoc;
3447 TemplateName TName = SubstDefaultTemplateArgument(*this, Template,
3454 return TemplateArgumentLoc();
3456 return TemplateArgumentLoc(TemplateArgument(TName),
3457 TempTempParm->getDefaultArgument().getTemplateQualifierLoc(),
3458 TempTempParm->getDefaultArgument().getTemplateNameLoc());
3461 /// \brief Check that the given template argument corresponds to the given
3462 /// template parameter.
3464 /// \param Param The template parameter against which the argument will be
3467 /// \param Arg The template argument, which may be updated due to conversions.
3469 /// \param Template The template in which the template argument resides.
3471 /// \param TemplateLoc The location of the template name for the template
3472 /// whose argument list we're matching.
3474 /// \param RAngleLoc The location of the right angle bracket ('>') that closes
3475 /// the template argument list.
3477 /// \param ArgumentPackIndex The index into the argument pack where this
3478 /// argument will be placed. Only valid if the parameter is a parameter pack.
3480 /// \param Converted The checked, converted argument will be added to the
3481 /// end of this small vector.
3483 /// \param CTAK Describes how we arrived at this particular template argument:
3484 /// explicitly written, deduced, etc.
3486 /// \returns true on error, false otherwise.
3487 bool Sema::CheckTemplateArgument(NamedDecl *Param,
3488 TemplateArgumentLoc &Arg,
3489 NamedDecl *Template,
3490 SourceLocation TemplateLoc,
3491 SourceLocation RAngleLoc,
3492 unsigned ArgumentPackIndex,
3493 SmallVectorImpl<TemplateArgument> &Converted,
3494 CheckTemplateArgumentKind CTAK) {
3495 // Check template type parameters.
3496 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param))
3497 return CheckTemplateTypeArgument(TTP, Arg, Converted);
3499 // Check non-type template parameters.
3500 if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3501 // Do substitution on the type of the non-type template parameter
3502 // with the template arguments we've seen thus far. But if the
3503 // template has a dependent context then we cannot substitute yet.
3504 QualType NTTPType = NTTP->getType();
3505 if (NTTP->isParameterPack() && NTTP->isExpandedParameterPack())
3506 NTTPType = NTTP->getExpansionType(ArgumentPackIndex);
3508 if (NTTPType->isDependentType() &&
3509 !isa<TemplateTemplateParmDecl>(Template) &&
3510 !Template->getDeclContext()->isDependentContext()) {
3511 // Do substitution on the type of the non-type template parameter.
3512 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
3514 SourceRange(TemplateLoc, RAngleLoc));
3515 if (Inst.isInvalid())
3518 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
3520 NTTPType = SubstType(NTTPType,
3521 MultiLevelTemplateArgumentList(TemplateArgs),
3522 NTTP->getLocation(),
3523 NTTP->getDeclName());
3524 // If that worked, check the non-type template parameter type
3526 if (!NTTPType.isNull())
3527 NTTPType = CheckNonTypeTemplateParameterType(NTTPType,
3528 NTTP->getLocation());
3529 if (NTTPType.isNull())
3533 switch (Arg.getArgument().getKind()) {
3534 case TemplateArgument::Null:
3535 llvm_unreachable("Should never see a NULL template argument here");
3537 case TemplateArgument::Expression: {
3538 TemplateArgument Result;
3540 CheckTemplateArgument(NTTP, NTTPType, Arg.getArgument().getAsExpr(),
3542 if (Res.isInvalid())
3545 // If the resulting expression is new, then use it in place of the
3546 // old expression in the template argument.
3547 if (Res.get() != Arg.getArgument().getAsExpr()) {
3548 TemplateArgument TA(Res.get());
3549 Arg = TemplateArgumentLoc(TA, Res.get());
3552 Converted.push_back(Result);
3556 case TemplateArgument::Declaration:
3557 case TemplateArgument::Integral:
3558 case TemplateArgument::NullPtr:
3559 // We've already checked this template argument, so just copy
3560 // it to the list of converted arguments.
3561 Converted.push_back(Arg.getArgument());
3564 case TemplateArgument::Template:
3565 case TemplateArgument::TemplateExpansion:
3566 // We were given a template template argument. It may not be ill-formed;
3568 if (DependentTemplateName *DTN
3569 = Arg.getArgument().getAsTemplateOrTemplatePattern()
3570 .getAsDependentTemplateName()) {
3571 // We have a template argument such as \c T::template X, which we
3572 // parsed as a template template argument. However, since we now
3573 // know that we need a non-type template argument, convert this
3574 // template name into an expression.
3576 DeclarationNameInfo NameInfo(DTN->getIdentifier(),
3577 Arg.getTemplateNameLoc());
3580 SS.Adopt(Arg.getTemplateQualifierLoc());
3581 // FIXME: the template-template arg was a DependentTemplateName,
3582 // so it was provided with a template keyword. However, its source
3583 // location is not stored in the template argument structure.
3584 SourceLocation TemplateKWLoc;
3585 ExprResult E = DependentScopeDeclRefExpr::Create(
3586 Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo,
3589 // If we parsed the template argument as a pack expansion, create a
3590 // pack expansion expression.
3591 if (Arg.getArgument().getKind() == TemplateArgument::TemplateExpansion){
3592 E = ActOnPackExpansion(E.get(), Arg.getTemplateEllipsisLoc());
3597 TemplateArgument Result;
3598 E = CheckTemplateArgument(NTTP, NTTPType, E.get(), Result);
3602 Converted.push_back(Result);
3606 // We have a template argument that actually does refer to a class
3607 // template, alias template, or template template parameter, and
3608 // therefore cannot be a non-type template argument.
3609 Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr)
3610 << Arg.getSourceRange();
3612 Diag(Param->getLocation(), diag::note_template_param_here);
3615 case TemplateArgument::Type: {
3616 // We have a non-type template parameter but the template
3617 // argument is a type.
3619 // C++ [temp.arg]p2:
3620 // In a template-argument, an ambiguity between a type-id and
3621 // an expression is resolved to a type-id, regardless of the
3622 // form of the corresponding template-parameter.
3624 // We warn specifically about this case, since it can be rather
3625 // confusing for users.
3626 QualType T = Arg.getArgument().getAsType();
3627 SourceRange SR = Arg.getSourceRange();
3628 if (T->isFunctionType())
3629 Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T;
3631 Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR;
3632 Diag(Param->getLocation(), diag::note_template_param_here);
3636 case TemplateArgument::Pack:
3637 llvm_unreachable("Caller must expand template argument packs");
3644 // Check template template parameters.
3645 TemplateTemplateParmDecl *TempParm = cast<TemplateTemplateParmDecl>(Param);
3647 // Substitute into the template parameter list of the template
3648 // template parameter, since previously-supplied template arguments
3649 // may appear within the template template parameter.
3651 // Set up a template instantiation context.
3652 LocalInstantiationScope Scope(*this);
3653 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
3654 TempParm, Converted,
3655 SourceRange(TemplateLoc, RAngleLoc));
3656 if (Inst.isInvalid())
3659 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
3660 TempParm = cast_or_null<TemplateTemplateParmDecl>(
3661 SubstDecl(TempParm, CurContext,
3662 MultiLevelTemplateArgumentList(TemplateArgs)));
3667 switch (Arg.getArgument().getKind()) {
3668 case TemplateArgument::Null:
3669 llvm_unreachable("Should never see a NULL template argument here");
3671 case TemplateArgument::Template:
3672 case TemplateArgument::TemplateExpansion:
3673 if (CheckTemplateArgument(TempParm, Arg, ArgumentPackIndex))
3676 Converted.push_back(Arg.getArgument());
3679 case TemplateArgument::Expression:
3680 case TemplateArgument::Type:
3681 // We have a template template parameter but the template
3682 // argument does not refer to a template.
3683 Diag(Arg.getLocation(), diag::err_template_arg_must_be_template)
3684 << getLangOpts().CPlusPlus11;
3687 case TemplateArgument::Declaration:
3688 llvm_unreachable("Declaration argument with template template parameter");
3689 case TemplateArgument::Integral:
3690 llvm_unreachable("Integral argument with template template parameter");
3691 case TemplateArgument::NullPtr:
3692 llvm_unreachable("Null pointer argument with template template parameter");
3694 case TemplateArgument::Pack:
3695 llvm_unreachable("Caller must expand template argument packs");
3701 /// \brief Diagnose an arity mismatch in the
3702 static bool diagnoseArityMismatch(Sema &S, TemplateDecl *Template,
3703 SourceLocation TemplateLoc,
3704 TemplateArgumentListInfo &TemplateArgs) {
3705 TemplateParameterList *Params = Template->getTemplateParameters();
3706 unsigned NumParams = Params->size();
3707 unsigned NumArgs = TemplateArgs.size();
3710 if (NumArgs > NumParams)
3711 Range = SourceRange(TemplateArgs[NumParams].getLocation(),
3712 TemplateArgs.getRAngleLoc());
3713 S.Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
3714 << (NumArgs > NumParams)
3715 << (isa<ClassTemplateDecl>(Template)? 0 :
3716 isa<FunctionTemplateDecl>(Template)? 1 :
3717 isa<TemplateTemplateParmDecl>(Template)? 2 : 3)
3718 << Template << Range;
3719 S.Diag(Template->getLocation(), diag::note_template_decl_here)
3720 << Params->getSourceRange();
3724 /// \brief Check whether the template parameter is a pack expansion, and if so,
3725 /// determine the number of parameters produced by that expansion. For instance:
3728 /// template<typename ...Ts> struct A {
3729 /// template<Ts ...NTs, template<Ts> class ...TTs, typename ...Us> struct B;
3733 /// In \c A<int,int>::B, \c NTs and \c TTs have expanded pack size 2, and \c Us
3734 /// is not a pack expansion, so returns an empty Optional.
3735 static Optional<unsigned> getExpandedPackSize(NamedDecl *Param) {
3736 if (NonTypeTemplateParmDecl *NTTP
3737 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
3738 if (NTTP->isExpandedParameterPack())
3739 return NTTP->getNumExpansionTypes();
3742 if (TemplateTemplateParmDecl *TTP
3743 = dyn_cast<TemplateTemplateParmDecl>(Param)) {
3744 if (TTP->isExpandedParameterPack())
3745 return TTP->getNumExpansionTemplateParameters();
3751 /// Diagnose a missing template argument.
3752 template<typename TemplateParmDecl>
3753 static bool diagnoseMissingArgument(Sema &S, SourceLocation Loc,
3755 const TemplateParmDecl *D,
3756 TemplateArgumentListInfo &Args) {
3757 // Dig out the most recent declaration of the template parameter; there may be
3758 // declarations of the template that are more recent than TD.
3759 D = cast<TemplateParmDecl>(cast<TemplateDecl>(TD->getMostRecentDecl())
3760 ->getTemplateParameters()
3761 ->getParam(D->getIndex()));
3763 // If there's a default argument that's not visible, diagnose that we're
3764 // missing a module import.
3765 llvm::SmallVector<Module*, 8> Modules;
3766 if (D->hasDefaultArgument() && !S.hasVisibleDefaultArgument(D, &Modules)) {
3767 S.diagnoseMissingImport(Loc, cast<NamedDecl>(TD),
3768 D->getDefaultArgumentLoc(), Modules,
3769 Sema::MissingImportKind::DefaultArgument,
3774 // FIXME: If there's a more recent default argument that *is* visible,
3775 // diagnose that it was declared too late.
3777 return diagnoseArityMismatch(S, TD, Loc, Args);
3780 /// \brief Check that the given template argument list is well-formed
3781 /// for specializing the given template.
3782 bool Sema::CheckTemplateArgumentList(TemplateDecl *Template,
3783 SourceLocation TemplateLoc,
3784 TemplateArgumentListInfo &TemplateArgs,
3785 bool PartialTemplateArgs,
3786 SmallVectorImpl<TemplateArgument> &Converted) {
3787 // Make a copy of the template arguments for processing. Only make the
3788 // changes at the end when successful in matching the arguments to the
3790 TemplateArgumentListInfo NewArgs = TemplateArgs;
3792 TemplateParameterList *Params = Template->getTemplateParameters();
3794 SourceLocation RAngleLoc = NewArgs.getRAngleLoc();
3796 // C++ [temp.arg]p1:
3797 // [...] The type and form of each template-argument specified in
3798 // a template-id shall match the type and form specified for the
3799 // corresponding parameter declared by the template in its
3800 // template-parameter-list.
3801 bool isTemplateTemplateParameter = isa<TemplateTemplateParmDecl>(Template);
3802 SmallVector<TemplateArgument, 2> ArgumentPack;
3803 unsigned ArgIdx = 0, NumArgs = NewArgs.size();
3804 LocalInstantiationScope InstScope(*this, true);
3805 for (TemplateParameterList::iterator Param = Params->begin(),
3806 ParamEnd = Params->end();
3807 Param != ParamEnd; /* increment in loop */) {
3808 // If we have an expanded parameter pack, make sure we don't have too
3810 if (Optional<unsigned> Expansions = getExpandedPackSize(*Param)) {
3811 if (*Expansions == ArgumentPack.size()) {
3812 // We're done with this parameter pack. Pack up its arguments and add
3813 // them to the list.
3814 Converted.push_back(
3815 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
3816 ArgumentPack.clear();
3818 // This argument is assigned to the next parameter.
3821 } else if (ArgIdx == NumArgs && !PartialTemplateArgs) {
3822 // Not enough arguments for this parameter pack.
3823 Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
3825 << (isa<ClassTemplateDecl>(Template)? 0 :
3826 isa<FunctionTemplateDecl>(Template)? 1 :
3827 isa<TemplateTemplateParmDecl>(Template)? 2 : 3)
3829 Diag(Template->getLocation(), diag::note_template_decl_here)
3830 << Params->getSourceRange();
3835 if (ArgIdx < NumArgs) {
3836 // Check the template argument we were given.
3837 if (CheckTemplateArgument(*Param, NewArgs[ArgIdx], Template,
3838 TemplateLoc, RAngleLoc,
3839 ArgumentPack.size(), Converted))
3842 bool PackExpansionIntoNonPack =
3843 NewArgs[ArgIdx].getArgument().isPackExpansion() &&
3844 (!(*Param)->isTemplateParameterPack() || getExpandedPackSize(*Param));
3845 if (PackExpansionIntoNonPack && isa<TypeAliasTemplateDecl>(Template)) {
3846 // Core issue 1430: we have a pack expansion as an argument to an
3847 // alias template, and it's not part of a parameter pack. This
3848 // can't be canonicalized, so reject it now.
3849 Diag(NewArgs[ArgIdx].getLocation(),
3850 diag::err_alias_template_expansion_into_fixed_list)
3851 << NewArgs[ArgIdx].getSourceRange();
3852 Diag((*Param)->getLocation(), diag::note_template_param_here);
3856 // We're now done with this argument.
3859 if ((*Param)->isTemplateParameterPack()) {
3860 // The template parameter was a template parameter pack, so take the
3861 // deduced argument and place it on the argument pack. Note that we
3862 // stay on the same template parameter so that we can deduce more
3864 ArgumentPack.push_back(Converted.pop_back_val());
3866 // Move to the next template parameter.
3870 // If we just saw a pack expansion into a non-pack, then directly convert
3871 // the remaining arguments, because we don't know what parameters they'll
3873 if (PackExpansionIntoNonPack) {
3874 if (!ArgumentPack.empty()) {
3875 // If we were part way through filling in an expanded parameter pack,
3876 // fall back to just producing individual arguments.
3877 Converted.insert(Converted.end(),
3878 ArgumentPack.begin(), ArgumentPack.end());
3879 ArgumentPack.clear();
3882 while (ArgIdx < NumArgs) {
3883 Converted.push_back(NewArgs[ArgIdx].getArgument());
3893 // If we're checking a partial template argument list, we're done.
3894 if (PartialTemplateArgs) {
3895 if ((*Param)->isTemplateParameterPack() && !ArgumentPack.empty())
3896 Converted.push_back(
3897 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
3902 // If we have a template parameter pack with no more corresponding
3903 // arguments, just break out now and we'll fill in the argument pack below.
3904 if ((*Param)->isTemplateParameterPack()) {
3905 assert(!getExpandedPackSize(*Param) &&
3906 "Should have dealt with this already");
3908 // A non-expanded parameter pack before the end of the parameter list
3909 // only occurs for an ill-formed template parameter list, unless we've
3910 // got a partial argument list for a function template, so just bail out.
3911 if (Param + 1 != ParamEnd)
3914 Converted.push_back(
3915 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
3916 ArgumentPack.clear();
3922 // Check whether we have a default argument.
3923 TemplateArgumentLoc Arg;
3925 // Retrieve the default template argument from the template
3926 // parameter. For each kind of template parameter, we substitute the
3927 // template arguments provided thus far and any "outer" template arguments
3928 // (when the template parameter was part of a nested template) into
3929 // the default argument.
3930 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*Param)) {
3931 if (!hasVisibleDefaultArgument(TTP))
3932 return diagnoseMissingArgument(*this, TemplateLoc, Template, TTP,
3935 TypeSourceInfo *ArgType = SubstDefaultTemplateArgument(*this,
3944 Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()),
3946 } else if (NonTypeTemplateParmDecl *NTTP
3947 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) {
3948 if (!hasVisibleDefaultArgument(NTTP))
3949 return diagnoseMissingArgument(*this, TemplateLoc, Template, NTTP,
3952 ExprResult E = SubstDefaultTemplateArgument(*this, Template,
3960 Expr *Ex = E.getAs<Expr>();
3961 Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex);
3963 TemplateTemplateParmDecl *TempParm
3964 = cast<TemplateTemplateParmDecl>(*Param);
3966 if (!hasVisibleDefaultArgument(TempParm))
3967 return diagnoseMissingArgument(*this, TemplateLoc, Template, TempParm,
3970 NestedNameSpecifierLoc QualifierLoc;
3971 TemplateName Name = SubstDefaultTemplateArgument(*this, Template,
3980 Arg = TemplateArgumentLoc(TemplateArgument(Name), QualifierLoc,
3981 TempParm->getDefaultArgument().getTemplateNameLoc());
3984 // Introduce an instantiation record that describes where we are using
3985 // the default template argument.
3986 InstantiatingTemplate Inst(*this, RAngleLoc, Template, *Param, Converted,
3987 SourceRange(TemplateLoc, RAngleLoc));
3988 if (Inst.isInvalid())
3991 // Check the default template argument.
3992 if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc,
3993 RAngleLoc, 0, Converted))
3996 // Core issue 150 (assumed resolution): if this is a template template
3997 // parameter, keep track of the default template arguments from the
3998 // template definition.
3999 if (isTemplateTemplateParameter)
4000 NewArgs.addArgument(Arg);
4002 // Move to the next template parameter and argument.
4007 // If we're performing a partial argument substitution, allow any trailing
4008 // pack expansions; they might be empty. This can happen even if
4009 // PartialTemplateArgs is false (the list of arguments is complete but
4010 // still dependent).
4011 if (ArgIdx < NumArgs && CurrentInstantiationScope &&
4012 CurrentInstantiationScope->getPartiallySubstitutedPack()) {
4013 while (ArgIdx < NumArgs && NewArgs[ArgIdx].getArgument().isPackExpansion())
4014 Converted.push_back(NewArgs[ArgIdx++].getArgument());
4017 // If we have any leftover arguments, then there were too many arguments.
4018 // Complain and fail.
4019 if (ArgIdx < NumArgs)
4020 return diagnoseArityMismatch(*this, Template, TemplateLoc, NewArgs);
4022 // No problems found with the new argument list, propagate changes back
4024 TemplateArgs = std::move(NewArgs);
4030 class UnnamedLocalNoLinkageFinder
4031 : public TypeVisitor<UnnamedLocalNoLinkageFinder, bool>
4036 typedef TypeVisitor<UnnamedLocalNoLinkageFinder, bool> inherited;
4039 UnnamedLocalNoLinkageFinder(Sema &S, SourceRange SR) : S(S), SR(SR) { }
4041 bool Visit(QualType T) {
4042 return inherited::Visit(T.getTypePtr());
4045 #define TYPE(Class, Parent) \
4046 bool Visit##Class##Type(const Class##Type *);
4047 #define ABSTRACT_TYPE(Class, Parent) \
4048 bool Visit##Class##Type(const Class##Type *) { return false; }
4049 #define NON_CANONICAL_TYPE(Class, Parent) \
4050 bool Visit##Class##Type(const Class##Type *) { return false; }
4051 #include "clang/AST/TypeNodes.def"
4053 bool VisitTagDecl(const TagDecl *Tag);
4054 bool VisitNestedNameSpecifier(NestedNameSpecifier *NNS);
4056 } // end anonymous namespace
4058 bool UnnamedLocalNoLinkageFinder::VisitBuiltinType(const BuiltinType*) {
4062 bool UnnamedLocalNoLinkageFinder::VisitComplexType(const ComplexType* T) {
4063 return Visit(T->getElementType());
4066 bool UnnamedLocalNoLinkageFinder::VisitPointerType(const PointerType* T) {
4067 return Visit(T->getPointeeType());
4070 bool UnnamedLocalNoLinkageFinder::VisitBlockPointerType(
4071 const BlockPointerType* T) {
4072 return Visit(T->getPointeeType());
4075 bool UnnamedLocalNoLinkageFinder::VisitLValueReferenceType(
4076 const LValueReferenceType* T) {
4077 return Visit(T->getPointeeType());
4080 bool UnnamedLocalNoLinkageFinder::VisitRValueReferenceType(
4081 const RValueReferenceType* T) {
4082 return Visit(T->getPointeeType());
4085 bool UnnamedLocalNoLinkageFinder::VisitMemberPointerType(
4086 const MemberPointerType* T) {
4087 return Visit(T->getPointeeType()) || Visit(QualType(T->getClass(), 0));
4090 bool UnnamedLocalNoLinkageFinder::VisitConstantArrayType(
4091 const ConstantArrayType* T) {
4092 return Visit(T->getElementType());
4095 bool UnnamedLocalNoLinkageFinder::VisitIncompleteArrayType(
4096 const IncompleteArrayType* T) {
4097 return Visit(T->getElementType());
4100 bool UnnamedLocalNoLinkageFinder::VisitVariableArrayType(
4101 const VariableArrayType* T) {
4102 return Visit(T->getElementType());
4105 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedArrayType(
4106 const DependentSizedArrayType* T) {
4107 return Visit(T->getElementType());
4110 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedExtVectorType(
4111 const DependentSizedExtVectorType* T) {
4112 return Visit(T->getElementType());
4115 bool UnnamedLocalNoLinkageFinder::VisitVectorType(const VectorType* T) {
4116 return Visit(T->getElementType());
4119 bool UnnamedLocalNoLinkageFinder::VisitExtVectorType(const ExtVectorType* T) {
4120 return Visit(T->getElementType());
4123 bool UnnamedLocalNoLinkageFinder::VisitFunctionProtoType(
4124 const FunctionProtoType* T) {
4125 for (const auto &A : T->param_types()) {
4130 return Visit(T->getReturnType());
4133 bool UnnamedLocalNoLinkageFinder::VisitFunctionNoProtoType(
4134 const FunctionNoProtoType* T) {
4135 return Visit(T->getReturnType());
4138 bool UnnamedLocalNoLinkageFinder::VisitUnresolvedUsingType(
4139 const UnresolvedUsingType*) {
4143 bool UnnamedLocalNoLinkageFinder::VisitTypeOfExprType(const TypeOfExprType*) {
4147 bool UnnamedLocalNoLinkageFinder::VisitTypeOfType(const TypeOfType* T) {
4148 return Visit(T->getUnderlyingType());
4151 bool UnnamedLocalNoLinkageFinder::VisitDecltypeType(const DecltypeType*) {
4155 bool UnnamedLocalNoLinkageFinder::VisitUnaryTransformType(
4156 const UnaryTransformType*) {
4160 bool UnnamedLocalNoLinkageFinder::VisitAutoType(const AutoType *T) {
4161 return Visit(T->getDeducedType());
4164 bool UnnamedLocalNoLinkageFinder::VisitRecordType(const RecordType* T) {
4165 return VisitTagDecl(T->getDecl());
4168 bool UnnamedLocalNoLinkageFinder::VisitEnumType(const EnumType* T) {
4169 return VisitTagDecl(T->getDecl());
4172 bool UnnamedLocalNoLinkageFinder::VisitTemplateTypeParmType(
4173 const TemplateTypeParmType*) {
4177 bool UnnamedLocalNoLinkageFinder::VisitSubstTemplateTypeParmPackType(
4178 const SubstTemplateTypeParmPackType *) {
4182 bool UnnamedLocalNoLinkageFinder::VisitTemplateSpecializationType(
4183 const TemplateSpecializationType*) {
4187 bool UnnamedLocalNoLinkageFinder::VisitInjectedClassNameType(
4188 const InjectedClassNameType* T) {
4189 return VisitTagDecl(T->getDecl());
4192 bool UnnamedLocalNoLinkageFinder::VisitDependentNameType(
4193 const DependentNameType* T) {
4194 return VisitNestedNameSpecifier(T->getQualifier());
4197 bool UnnamedLocalNoLinkageFinder::VisitDependentTemplateSpecializationType(
4198 const DependentTemplateSpecializationType* T) {
4199 return VisitNestedNameSpecifier(T->getQualifier());
4202 bool UnnamedLocalNoLinkageFinder::VisitPackExpansionType(
4203 const PackExpansionType* T) {
4204 return Visit(T->getPattern());
4207 bool UnnamedLocalNoLinkageFinder::VisitObjCObjectType(const ObjCObjectType *) {
4211 bool UnnamedLocalNoLinkageFinder::VisitObjCInterfaceType(
4212 const ObjCInterfaceType *) {
4216 bool UnnamedLocalNoLinkageFinder::VisitObjCObjectPointerType(
4217 const ObjCObjectPointerType *) {
4221 bool UnnamedLocalNoLinkageFinder::VisitAtomicType(const AtomicType* T) {
4222 return Visit(T->getValueType());
4225 bool UnnamedLocalNoLinkageFinder::VisitPipeType(const PipeType* T) {
4229 bool UnnamedLocalNoLinkageFinder::VisitTagDecl(const TagDecl *Tag) {
4230 if (Tag->getDeclContext()->isFunctionOrMethod()) {
4231 S.Diag(SR.getBegin(),
4232 S.getLangOpts().CPlusPlus11 ?
4233 diag::warn_cxx98_compat_template_arg_local_type :
4234 diag::ext_template_arg_local_type)
4235 << S.Context.getTypeDeclType(Tag) << SR;
4239 if (!Tag->hasNameForLinkage()) {
4240 S.Diag(SR.getBegin(),
4241 S.getLangOpts().CPlusPlus11 ?
4242 diag::warn_cxx98_compat_template_arg_unnamed_type :
4243 diag::ext_template_arg_unnamed_type) << SR;
4244 S.Diag(Tag->getLocation(), diag::note_template_unnamed_type_here);
4251 bool UnnamedLocalNoLinkageFinder::VisitNestedNameSpecifier(
4252 NestedNameSpecifier *NNS) {
4253 if (NNS->getPrefix() && VisitNestedNameSpecifier(NNS->getPrefix()))
4256 switch (NNS->getKind()) {
4257 case NestedNameSpecifier::Identifier:
4258 case NestedNameSpecifier::Namespace:
4259 case NestedNameSpecifier::NamespaceAlias:
4260 case NestedNameSpecifier::Global:
4261 case NestedNameSpecifier::Super:
4264 case NestedNameSpecifier::TypeSpec:
4265 case NestedNameSpecifier::TypeSpecWithTemplate:
4266 return Visit(QualType(NNS->getAsType(), 0));
4268 llvm_unreachable("Invalid NestedNameSpecifier::Kind!");
4271 /// \brief Check a template argument against its corresponding
4272 /// template type parameter.
4274 /// This routine implements the semantics of C++ [temp.arg.type]. It
4275 /// returns true if an error occurred, and false otherwise.
4276 bool Sema::CheckTemplateArgument(TemplateTypeParmDecl *Param,
4277 TypeSourceInfo *ArgInfo) {
4278 assert(ArgInfo && "invalid TypeSourceInfo");
4279 QualType Arg = ArgInfo->getType();
4280 SourceRange SR = ArgInfo->getTypeLoc().getSourceRange();
4282 if (Arg->isVariablyModifiedType()) {
4283 return Diag(SR.getBegin(), diag::err_variably_modified_template_arg) << Arg;
4284 } else if (Context.hasSameUnqualifiedType(Arg, Context.OverloadTy)) {
4285 return Diag(SR.getBegin(), diag::err_template_arg_overload_type) << SR;
4288 // C++03 [temp.arg.type]p2:
4289 // A local type, a type with no linkage, an unnamed type or a type
4290 // compounded from any of these types shall not be used as a
4291 // template-argument for a template type-parameter.
4293 // C++11 allows these, and even in C++03 we allow them as an extension with
4296 if (LangOpts.CPlusPlus11)
4298 !Diags.isIgnored(diag::warn_cxx98_compat_template_arg_unnamed_type,
4300 !Diags.isIgnored(diag::warn_cxx98_compat_template_arg_local_type,
4303 NeedsCheck = Arg->hasUnnamedOrLocalType();
4306 UnnamedLocalNoLinkageFinder Finder(*this, SR);
4307 (void)Finder.Visit(Context.getCanonicalType(Arg));
4313 enum NullPointerValueKind {
4319 /// \brief Determine whether the given template argument is a null pointer
4320 /// value of the appropriate type.
4321 static NullPointerValueKind
4322 isNullPointerValueTemplateArgument(Sema &S, NonTypeTemplateParmDecl *Param,
4323 QualType ParamType, Expr *Arg) {
4324 if (Arg->isValueDependent() || Arg->isTypeDependent())
4325 return NPV_NotNullPointer;
4327 if (!S.isCompleteType(Arg->getExprLoc(), ParamType))
4329 "Incomplete parameter type in isNullPointerValueTemplateArgument!");
4331 if (!S.getLangOpts().CPlusPlus11)
4332 return NPV_NotNullPointer;
4334 // Determine whether we have a constant expression.
4335 ExprResult ArgRV = S.DefaultFunctionArrayConversion(Arg);
4336 if (ArgRV.isInvalid())
4340 Expr::EvalResult EvalResult;
4341 SmallVector<PartialDiagnosticAt, 8> Notes;
4342 EvalResult.Diag = &Notes;
4343 if (!Arg->EvaluateAsRValue(EvalResult, S.Context) ||
4344 EvalResult.HasSideEffects) {
4345 SourceLocation DiagLoc = Arg->getExprLoc();
4347 // If our only note is the usual "invalid subexpression" note, just point
4348 // the caret at its location rather than producing an essentially
4350 if (Notes.size() == 1 && Notes[0].second.getDiagID() ==
4351 diag::note_invalid_subexpr_in_const_expr) {
4352 DiagLoc = Notes[0].first;
4356 S.Diag(DiagLoc, diag::err_template_arg_not_address_constant)
4357 << Arg->getType() << Arg->getSourceRange();
4358 for (unsigned I = 0, N = Notes.size(); I != N; ++I)
4359 S.Diag(Notes[I].first, Notes[I].second);
4361 S.Diag(Param->getLocation(), diag::note_template_param_here);
4365 // C++11 [temp.arg.nontype]p1:
4366 // - an address constant expression of type std::nullptr_t
4367 if (Arg->getType()->isNullPtrType())
4368 return NPV_NullPointer;
4370 // - a constant expression that evaluates to a null pointer value (4.10); or
4371 // - a constant expression that evaluates to a null member pointer value
4373 if ((EvalResult.Val.isLValue() && !EvalResult.Val.getLValueBase()) ||
4374 (EvalResult.Val.isMemberPointer() &&
4375 !EvalResult.Val.getMemberPointerDecl())) {
4376 // If our expression has an appropriate type, we've succeeded.
4377 bool ObjCLifetimeConversion;
4378 if (S.Context.hasSameUnqualifiedType(Arg->getType(), ParamType) ||
4379 S.IsQualificationConversion(Arg->getType(), ParamType, false,
4380 ObjCLifetimeConversion))
4381 return NPV_NullPointer;
4383 // The types didn't match, but we know we got a null pointer; complain,
4384 // then recover as if the types were correct.
4385 S.Diag(Arg->getExprLoc(), diag::err_template_arg_wrongtype_null_constant)
4386 << Arg->getType() << ParamType << Arg->getSourceRange();
4387 S.Diag(Param->getLocation(), diag::note_template_param_here);
4388 return NPV_NullPointer;
4391 // If we don't have a null pointer value, but we do have a NULL pointer
4392 // constant, suggest a cast to the appropriate type.
4393 if (Arg->isNullPointerConstant(S.Context, Expr::NPC_NeverValueDependent)) {
4394 std::string Code = "static_cast<" + ParamType.getAsString() + ">(";
4395 S.Diag(Arg->getExprLoc(), diag::err_template_arg_untyped_null_constant)
4396 << ParamType << FixItHint::CreateInsertion(Arg->getLocStart(), Code)
4397 << FixItHint::CreateInsertion(S.getLocForEndOfToken(Arg->getLocEnd()),
4399 S.Diag(Param->getLocation(), diag::note_template_param_here);
4400 return NPV_NullPointer;
4403 // FIXME: If we ever want to support general, address-constant expressions
4404 // as non-type template arguments, we should return the ExprResult here to
4405 // be interpreted by the caller.
4406 return NPV_NotNullPointer;
4409 /// \brief Checks whether the given template argument is compatible with its
4410 /// template parameter.
4411 static bool CheckTemplateArgumentIsCompatibleWithParameter(
4412 Sema &S, NonTypeTemplateParmDecl *Param, QualType ParamType, Expr *ArgIn,
4413 Expr *Arg, QualType ArgType) {
4414 bool ObjCLifetimeConversion;
4415 if (ParamType->isPointerType() &&
4416 !ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType() &&
4417 S.IsQualificationConversion(ArgType, ParamType, false,
4418 ObjCLifetimeConversion)) {
4419 // For pointer-to-object types, qualification conversions are
4422 if (const ReferenceType *ParamRef = ParamType->getAs<ReferenceType>()) {
4423 if (!ParamRef->getPointeeType()->isFunctionType()) {
4424 // C++ [temp.arg.nontype]p5b3:
4425 // For a non-type template-parameter of type reference to
4426 // object, no conversions apply. The type referred to by the
4427 // reference may be more cv-qualified than the (otherwise
4428 // identical) type of the template- argument. The
4429 // template-parameter is bound directly to the
4430 // template-argument, which shall be an lvalue.
4432 // FIXME: Other qualifiers?
4433 unsigned ParamQuals = ParamRef->getPointeeType().getCVRQualifiers();
4434 unsigned ArgQuals = ArgType.getCVRQualifiers();
4436 if ((ParamQuals | ArgQuals) != ParamQuals) {
4437 S.Diag(Arg->getLocStart(),
4438 diag::err_template_arg_ref_bind_ignores_quals)
4439 << ParamType << Arg->getType() << Arg->getSourceRange();
4440 S.Diag(Param->getLocation(), diag::note_template_param_here);
4446 // At this point, the template argument refers to an object or
4447 // function with external linkage. We now need to check whether the
4448 // argument and parameter types are compatible.
4449 if (!S.Context.hasSameUnqualifiedType(ArgType,
4450 ParamType.getNonReferenceType())) {
4451 // We can't perform this conversion or binding.
4452 if (ParamType->isReferenceType())
4453 S.Diag(Arg->getLocStart(), diag::err_template_arg_no_ref_bind)
4454 << ParamType << ArgIn->getType() << Arg->getSourceRange();
4456 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible)
4457 << ArgIn->getType() << ParamType << Arg->getSourceRange();
4458 S.Diag(Param->getLocation(), diag::note_template_param_here);
4466 /// \brief Checks whether the given template argument is the address
4467 /// of an object or function according to C++ [temp.arg.nontype]p1.
4469 CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S,
4470 NonTypeTemplateParmDecl *Param,
4473 TemplateArgument &Converted) {
4474 bool Invalid = false;
4476 QualType ArgType = Arg->getType();
4478 bool AddressTaken = false;
4479 SourceLocation AddrOpLoc;
4480 if (S.getLangOpts().MicrosoftExt) {
4481 // Microsoft Visual C++ strips all casts, allows an arbitrary number of
4482 // dereference and address-of operators.
4483 Arg = Arg->IgnoreParenCasts();
4485 bool ExtWarnMSTemplateArg = false;
4486 UnaryOperatorKind FirstOpKind;
4487 SourceLocation FirstOpLoc;
4488 while (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
4489 UnaryOperatorKind UnOpKind = UnOp->getOpcode();
4490 if (UnOpKind == UO_Deref)
4491 ExtWarnMSTemplateArg = true;
4492 if (UnOpKind == UO_AddrOf || UnOpKind == UO_Deref) {
4493 Arg = UnOp->getSubExpr()->IgnoreParenCasts();
4494 if (!AddrOpLoc.isValid()) {
4495 FirstOpKind = UnOpKind;
4496 FirstOpLoc = UnOp->getOperatorLoc();
4501 if (FirstOpLoc.isValid()) {
4502 if (ExtWarnMSTemplateArg)
4503 S.Diag(ArgIn->getLocStart(), diag::ext_ms_deref_template_argument)
4504 << ArgIn->getSourceRange();
4506 if (FirstOpKind == UO_AddrOf)
4507 AddressTaken = true;
4508 else if (Arg->getType()->isPointerType()) {
4509 // We cannot let pointers get dereferenced here, that is obviously not a
4510 // constant expression.
4511 assert(FirstOpKind == UO_Deref);
4512 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
4513 << Arg->getSourceRange();
4517 // See through any implicit casts we added to fix the type.
4518 Arg = Arg->IgnoreImpCasts();
4520 // C++ [temp.arg.nontype]p1:
4522 // A template-argument for a non-type, non-template
4523 // template-parameter shall be one of: [...]
4525 // -- the address of an object or function with external
4526 // linkage, including function templates and function
4527 // template-ids but excluding non-static class members,
4528 // expressed as & id-expression where the & is optional if
4529 // the name refers to a function or array, or if the
4530 // corresponding template-parameter is a reference; or
4532 // In C++98/03 mode, give an extension warning on any extra parentheses.
4533 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
4534 bool ExtraParens = false;
4535 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) {
4536 if (!Invalid && !ExtraParens) {
4537 S.Diag(Arg->getLocStart(),
4538 S.getLangOpts().CPlusPlus11
4539 ? diag::warn_cxx98_compat_template_arg_extra_parens
4540 : diag::ext_template_arg_extra_parens)
4541 << Arg->getSourceRange();
4545 Arg = Parens->getSubExpr();
4548 while (SubstNonTypeTemplateParmExpr *subst =
4549 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
4550 Arg = subst->getReplacement()->IgnoreImpCasts();
4552 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
4553 if (UnOp->getOpcode() == UO_AddrOf) {
4554 Arg = UnOp->getSubExpr();
4555 AddressTaken = true;
4556 AddrOpLoc = UnOp->getOperatorLoc();
4560 while (SubstNonTypeTemplateParmExpr *subst =
4561 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
4562 Arg = subst->getReplacement()->IgnoreImpCasts();
4565 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg);
4566 ValueDecl *Entity = DRE ? DRE->getDecl() : nullptr;
4568 // If our parameter has pointer type, check for a null template value.
4569 if (ParamType->isPointerType() || ParamType->isNullPtrType()) {
4570 NullPointerValueKind NPV;
4571 // dllimport'd entities aren't constant but are available inside of template
4573 if (Entity && Entity->hasAttr<DLLImportAttr>())
4574 NPV = NPV_NotNullPointer;
4576 NPV = isNullPointerValueTemplateArgument(S, Param, ParamType, ArgIn);
4578 case NPV_NullPointer:
4579 S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
4580 Converted = TemplateArgument(S.Context.getCanonicalType(ParamType),
4581 /*isNullPtr=*/true);
4587 case NPV_NotNullPointer:
4592 // Stop checking the precise nature of the argument if it is value dependent,
4593 // it should be checked when instantiated.
4594 if (Arg->isValueDependent()) {
4595 Converted = TemplateArgument(ArgIn);
4599 if (isa<CXXUuidofExpr>(Arg)) {
4600 if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType,
4601 ArgIn, Arg, ArgType))
4604 Converted = TemplateArgument(ArgIn);
4609 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
4610 << Arg->getSourceRange();
4611 S.Diag(Param->getLocation(), diag::note_template_param_here);
4615 // Cannot refer to non-static data members
4616 if (isa<FieldDecl>(Entity) || isa<IndirectFieldDecl>(Entity)) {
4617 S.Diag(Arg->getLocStart(), diag::err_template_arg_field)
4618 << Entity << Arg->getSourceRange();
4619 S.Diag(Param->getLocation(), diag::note_template_param_here);
4623 // Cannot refer to non-static member functions
4624 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Entity)) {
4625 if (!Method->isStatic()) {
4626 S.Diag(Arg->getLocStart(), diag::err_template_arg_method)
4627 << Method << Arg->getSourceRange();
4628 S.Diag(Param->getLocation(), diag::note_template_param_here);
4633 FunctionDecl *Func = dyn_cast<FunctionDecl>(Entity);
4634 VarDecl *Var = dyn_cast<VarDecl>(Entity);
4636 // A non-type template argument must refer to an object or function.
4637 if (!Func && !Var) {
4638 // We found something, but we don't know specifically what it is.
4639 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_object_or_func)
4640 << Arg->getSourceRange();
4641 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here);
4645 // Address / reference template args must have external linkage in C++98.
4646 if (Entity->getFormalLinkage() == InternalLinkage) {
4647 S.Diag(Arg->getLocStart(), S.getLangOpts().CPlusPlus11 ?
4648 diag::warn_cxx98_compat_template_arg_object_internal :
4649 diag::ext_template_arg_object_internal)
4650 << !Func << Entity << Arg->getSourceRange();
4651 S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
4653 } else if (!Entity->hasLinkage()) {
4654 S.Diag(Arg->getLocStart(), diag::err_template_arg_object_no_linkage)
4655 << !Func << Entity << Arg->getSourceRange();
4656 S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
4662 // If the template parameter has pointer type, the function decays.
4663 if (ParamType->isPointerType() && !AddressTaken)
4664 ArgType = S.Context.getPointerType(Func->getType());
4665 else if (AddressTaken && ParamType->isReferenceType()) {
4666 // If we originally had an address-of operator, but the
4667 // parameter has reference type, complain and (if things look
4668 // like they will work) drop the address-of operator.
4669 if (!S.Context.hasSameUnqualifiedType(Func->getType(),
4670 ParamType.getNonReferenceType())) {
4671 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4673 S.Diag(Param->getLocation(), diag::note_template_param_here);
4677 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4679 << FixItHint::CreateRemoval(AddrOpLoc);
4680 S.Diag(Param->getLocation(), diag::note_template_param_here);
4682 ArgType = Func->getType();
4685 // A value of reference type is not an object.
4686 if (Var->getType()->isReferenceType()) {
4687 S.Diag(Arg->getLocStart(),
4688 diag::err_template_arg_reference_var)
4689 << Var->getType() << Arg->getSourceRange();
4690 S.Diag(Param->getLocation(), diag::note_template_param_here);
4694 // A template argument must have static storage duration.
4695 if (Var->getTLSKind()) {
4696 S.Diag(Arg->getLocStart(), diag::err_template_arg_thread_local)
4697 << Arg->getSourceRange();
4698 S.Diag(Var->getLocation(), diag::note_template_arg_refers_here);
4702 // If the template parameter has pointer type, we must have taken
4703 // the address of this object.
4704 if (ParamType->isReferenceType()) {
4706 // If we originally had an address-of operator, but the
4707 // parameter has reference type, complain and (if things look
4708 // like they will work) drop the address-of operator.
4709 if (!S.Context.hasSameUnqualifiedType(Var->getType(),
4710 ParamType.getNonReferenceType())) {
4711 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4713 S.Diag(Param->getLocation(), diag::note_template_param_here);
4717 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
4719 << FixItHint::CreateRemoval(AddrOpLoc);
4720 S.Diag(Param->getLocation(), diag::note_template_param_here);
4722 ArgType = Var->getType();
4724 } else if (!AddressTaken && ParamType->isPointerType()) {
4725 if (Var->getType()->isArrayType()) {
4726 // Array-to-pointer decay.
4727 ArgType = S.Context.getArrayDecayedType(Var->getType());
4729 // If the template parameter has pointer type but the address of
4730 // this object was not taken, complain and (possibly) recover by
4731 // taking the address of the entity.
4732 ArgType = S.Context.getPointerType(Var->getType());
4733 if (!S.Context.hasSameUnqualifiedType(ArgType, ParamType)) {
4734 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of)
4736 S.Diag(Param->getLocation(), diag::note_template_param_here);
4740 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of)
4742 << FixItHint::CreateInsertion(Arg->getLocStart(), "&");
4744 S.Diag(Param->getLocation(), diag::note_template_param_here);
4749 if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType, ArgIn,
4753 // Create the template argument.
4755 TemplateArgument(cast<ValueDecl>(Entity->getCanonicalDecl()), ParamType);
4756 S.MarkAnyDeclReferenced(Arg->getLocStart(), Entity, false);
4760 /// \brief Checks whether the given template argument is a pointer to
4761 /// member constant according to C++ [temp.arg.nontype]p1.
4762 static bool CheckTemplateArgumentPointerToMember(Sema &S,
4763 NonTypeTemplateParmDecl *Param,
4766 TemplateArgument &Converted) {
4767 bool Invalid = false;
4769 // Check for a null pointer value.
4770 Expr *Arg = ResultArg;
4771 switch (isNullPointerValueTemplateArgument(S, Param, ParamType, Arg)) {
4774 case NPV_NullPointer:
4775 S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
4776 Converted = TemplateArgument(S.Context.getCanonicalType(ParamType),
4779 case NPV_NotNullPointer:
4783 bool ObjCLifetimeConversion;
4784 if (S.IsQualificationConversion(Arg->getType(),
4785 ParamType.getNonReferenceType(),
4786 false, ObjCLifetimeConversion)) {
4787 Arg = S.ImpCastExprToType(Arg, ParamType, CK_NoOp,
4788 Arg->getValueKind()).get();
4790 } else if (!S.Context.hasSameUnqualifiedType(Arg->getType(),
4791 ParamType.getNonReferenceType())) {
4792 // We can't perform this conversion.
4793 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible)
4794 << Arg->getType() << ParamType << Arg->getSourceRange();
4795 S.Diag(Param->getLocation(), diag::note_template_param_here);
4799 // See through any implicit casts we added to fix the type.
4800 while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg))
4801 Arg = Cast->getSubExpr();
4803 // C++ [temp.arg.nontype]p1:
4805 // A template-argument for a non-type, non-template
4806 // template-parameter shall be one of: [...]
4808 // -- a pointer to member expressed as described in 5.3.1.
4809 DeclRefExpr *DRE = nullptr;
4811 // In C++98/03 mode, give an extension warning on any extra parentheses.
4812 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
4813 bool ExtraParens = false;
4814 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) {
4815 if (!Invalid && !ExtraParens) {
4816 S.Diag(Arg->getLocStart(),
4817 S.getLangOpts().CPlusPlus11 ?
4818 diag::warn_cxx98_compat_template_arg_extra_parens :
4819 diag::ext_template_arg_extra_parens)
4820 << Arg->getSourceRange();
4824 Arg = Parens->getSubExpr();
4827 while (SubstNonTypeTemplateParmExpr *subst =
4828 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
4829 Arg = subst->getReplacement()->IgnoreImpCasts();
4831 // A pointer-to-member constant written &Class::member.
4832 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
4833 if (UnOp->getOpcode() == UO_AddrOf) {
4834 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr());
4835 if (DRE && !DRE->getQualifier())
4839 // A constant of pointer-to-member type.
4840 else if ((DRE = dyn_cast<DeclRefExpr>(Arg))) {
4841 if (ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl())) {
4842 if (VD->getType()->isMemberPointerType()) {
4843 if (isa<NonTypeTemplateParmDecl>(VD)) {
4844 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
4845 Converted = TemplateArgument(Arg);
4847 VD = cast<ValueDecl>(VD->getCanonicalDecl());
4848 Converted = TemplateArgument(VD, ParamType);
4859 return S.Diag(Arg->getLocStart(),
4860 diag::err_template_arg_not_pointer_to_member_form)
4861 << Arg->getSourceRange();
4863 if (isa<FieldDecl>(DRE->getDecl()) ||
4864 isa<IndirectFieldDecl>(DRE->getDecl()) ||
4865 isa<CXXMethodDecl>(DRE->getDecl())) {
4866 assert((isa<FieldDecl>(DRE->getDecl()) ||
4867 isa<IndirectFieldDecl>(DRE->getDecl()) ||
4868 !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) &&
4869 "Only non-static member pointers can make it here");
4871 // Okay: this is the address of a non-static member, and therefore
4872 // a member pointer constant.
4873 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
4874 Converted = TemplateArgument(Arg);
4876 ValueDecl *D = cast<ValueDecl>(DRE->getDecl()->getCanonicalDecl());
4877 Converted = TemplateArgument(D, ParamType);
4882 // We found something else, but we don't know specifically what it is.
4883 S.Diag(Arg->getLocStart(),
4884 diag::err_template_arg_not_pointer_to_member_form)
4885 << Arg->getSourceRange();
4886 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here);
4890 /// \brief Check a template argument against its corresponding
4891 /// non-type template parameter.
4893 /// This routine implements the semantics of C++ [temp.arg.nontype].
4894 /// If an error occurred, it returns ExprError(); otherwise, it
4895 /// returns the converted template argument. \p ParamType is the
4896 /// type of the non-type template parameter after it has been instantiated.
4897 ExprResult Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
4898 QualType ParamType, Expr *Arg,
4899 TemplateArgument &Converted,
4900 CheckTemplateArgumentKind CTAK) {
4901 SourceLocation StartLoc = Arg->getLocStart();
4903 // If either the parameter has a dependent type or the argument is
4904 // type-dependent, there's nothing we can check now.
4905 if (ParamType->isDependentType() || Arg->isTypeDependent()) {
4906 // FIXME: Produce a cloned, canonical expression?
4907 Converted = TemplateArgument(Arg);
4911 // We should have already dropped all cv-qualifiers by now.
4912 assert(!ParamType.hasQualifiers() &&
4913 "non-type template parameter type cannot be qualified");
4915 if (CTAK == CTAK_Deduced &&
4916 !Context.hasSameUnqualifiedType(ParamType, Arg->getType())) {
4917 // C++ [temp.deduct.type]p17:
4918 // If, in the declaration of a function template with a non-type
4919 // template-parameter, the non-type template-parameter is used
4920 // in an expression in the function parameter-list and, if the
4921 // corresponding template-argument is deduced, the
4922 // template-argument type shall match the type of the
4923 // template-parameter exactly, except that a template-argument
4924 // deduced from an array bound may be of any integral type.
4925 Diag(StartLoc, diag::err_deduced_non_type_template_arg_type_mismatch)
4926 << Arg->getType().getUnqualifiedType()
4927 << ParamType.getUnqualifiedType();
4928 Diag(Param->getLocation(), diag::note_template_param_here);
4932 if (getLangOpts().CPlusPlus1z) {
4933 // FIXME: We can do some limited checking for a value-dependent but not
4934 // type-dependent argument.
4935 if (Arg->isValueDependent()) {
4936 Converted = TemplateArgument(Arg);
4940 // C++1z [temp.arg.nontype]p1:
4941 // A template-argument for a non-type template parameter shall be
4942 // a converted constant expression of the type of the template-parameter.
4944 ExprResult ArgResult = CheckConvertedConstantExpression(
4945 Arg, ParamType, Value, CCEK_TemplateArg);
4946 if (ArgResult.isInvalid())
4949 QualType CanonParamType = Context.getCanonicalType(ParamType);
4951 // Convert the APValue to a TemplateArgument.
4952 switch (Value.getKind()) {
4953 case APValue::Uninitialized:
4954 assert(ParamType->isNullPtrType());
4955 Converted = TemplateArgument(CanonParamType, /*isNullPtr*/true);
4958 assert(ParamType->isIntegralOrEnumerationType());
4959 Converted = TemplateArgument(Context, Value.getInt(), CanonParamType);
4961 case APValue::MemberPointer: {
4962 assert(ParamType->isMemberPointerType());
4964 // FIXME: We need TemplateArgument representation and mangling for these.
4965 if (!Value.getMemberPointerPath().empty()) {
4966 Diag(Arg->getLocStart(),
4967 diag::err_template_arg_member_ptr_base_derived_not_supported)
4968 << Value.getMemberPointerDecl() << ParamType
4969 << Arg->getSourceRange();
4973 auto *VD = const_cast<ValueDecl*>(Value.getMemberPointerDecl());
4974 Converted = VD ? TemplateArgument(VD, CanonParamType)
4975 : TemplateArgument(CanonParamType, /*isNullPtr*/true);
4978 case APValue::LValue: {
4979 // For a non-type template-parameter of pointer or reference type,
4980 // the value of the constant expression shall not refer to
4981 assert(ParamType->isPointerType() || ParamType->isReferenceType() ||
4982 ParamType->isNullPtrType());
4983 // -- a temporary object
4984 // -- a string literal
4985 // -- the result of a typeid expression, or
4986 // -- a predefind __func__ variable
4987 if (auto *E = Value.getLValueBase().dyn_cast<const Expr*>()) {
4988 if (isa<CXXUuidofExpr>(E)) {
4989 Converted = TemplateArgument(const_cast<Expr*>(E));
4992 Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
4993 << Arg->getSourceRange();
4996 auto *VD = const_cast<ValueDecl *>(
4997 Value.getLValueBase().dyn_cast<const ValueDecl *>());
4999 if (Value.hasLValuePath() && Value.getLValuePath().size() == 1 &&
5000 VD && VD->getType()->isArrayType() &&
5001 Value.getLValuePath()[0].ArrayIndex == 0 &&
5002 !Value.isLValueOnePastTheEnd() && ParamType->isPointerType()) {
5003 // Per defect report (no number yet):
5004 // ... other than a pointer to the first element of a complete array
5006 } else if (!Value.hasLValuePath() || Value.getLValuePath().size() ||
5007 Value.isLValueOnePastTheEnd()) {
5008 Diag(StartLoc, diag::err_non_type_template_arg_subobject)
5009 << Value.getAsString(Context, ParamType);
5012 assert((VD || !ParamType->isReferenceType()) &&
5013 "null reference should not be a constant expression");
5014 assert((!VD || !ParamType->isNullPtrType()) &&
5015 "non-null value of type nullptr_t?");
5016 Converted = VD ? TemplateArgument(VD, CanonParamType)
5017 : TemplateArgument(CanonParamType, /*isNullPtr*/true);
5020 case APValue::AddrLabelDiff:
5021 return Diag(StartLoc, diag::err_non_type_template_arg_addr_label_diff);
5022 case APValue::Float:
5023 case APValue::ComplexInt:
5024 case APValue::ComplexFloat:
5025 case APValue::Vector:
5026 case APValue::Array:
5027 case APValue::Struct:
5028 case APValue::Union:
5029 llvm_unreachable("invalid kind for template argument");
5032 return ArgResult.get();
5035 // C++ [temp.arg.nontype]p5:
5036 // The following conversions are performed on each expression used
5037 // as a non-type template-argument. If a non-type
5038 // template-argument cannot be converted to the type of the
5039 // corresponding template-parameter then the program is
5041 if (ParamType->isIntegralOrEnumerationType()) {
5043 // -- for a non-type template-parameter of integral or
5044 // enumeration type, conversions permitted in a converted
5045 // constant expression are applied.
5048 // -- for a non-type template-parameter of integral or
5049 // enumeration type, integral promotions (4.5) and integral
5050 // conversions (4.7) are applied.
5052 if (getLangOpts().CPlusPlus11) {
5053 // We can't check arbitrary value-dependent arguments.
5054 // FIXME: If there's no viable conversion to the template parameter type,
5055 // we should be able to diagnose that prior to instantiation.
5056 if (Arg->isValueDependent()) {
5057 Converted = TemplateArgument(Arg);
5061 // C++ [temp.arg.nontype]p1:
5062 // A template-argument for a non-type, non-template template-parameter
5065 // -- for a non-type template-parameter of integral or enumeration
5066 // type, a converted constant expression of the type of the
5067 // template-parameter; or
5069 ExprResult ArgResult =
5070 CheckConvertedConstantExpression(Arg, ParamType, Value,
5072 if (ArgResult.isInvalid())
5075 // Widen the argument value to sizeof(parameter type). This is almost
5076 // always a no-op, except when the parameter type is bool. In
5077 // that case, this may extend the argument from 1 bit to 8 bits.
5078 QualType IntegerType = ParamType;
5079 if (const EnumType *Enum = IntegerType->getAs<EnumType>())
5080 IntegerType = Enum->getDecl()->getIntegerType();
5081 Value = Value.extOrTrunc(Context.getTypeSize(IntegerType));
5083 Converted = TemplateArgument(Context, Value,
5084 Context.getCanonicalType(ParamType));
5088 ExprResult ArgResult = DefaultLvalueConversion(Arg);
5089 if (ArgResult.isInvalid())
5091 Arg = ArgResult.get();
5093 QualType ArgType = Arg->getType();
5095 // C++ [temp.arg.nontype]p1:
5096 // A template-argument for a non-type, non-template
5097 // template-parameter shall be one of:
5099 // -- an integral constant-expression of integral or enumeration
5101 // -- the name of a non-type template-parameter; or
5102 SourceLocation NonConstantLoc;
5104 if (!ArgType->isIntegralOrEnumerationType()) {
5105 Diag(Arg->getLocStart(),
5106 diag::err_template_arg_not_integral_or_enumeral)
5107 << ArgType << Arg->getSourceRange();
5108 Diag(Param->getLocation(), diag::note_template_param_here);
5110 } else if (!Arg->isValueDependent()) {
5111 class TmplArgICEDiagnoser : public VerifyICEDiagnoser {
5115 TmplArgICEDiagnoser(QualType T) : T(T) { }
5117 void diagnoseNotICE(Sema &S, SourceLocation Loc,
5118 SourceRange SR) override {
5119 S.Diag(Loc, diag::err_template_arg_not_ice) << T << SR;
5121 } Diagnoser(ArgType);
5123 Arg = VerifyIntegerConstantExpression(Arg, &Value, Diagnoser,
5129 // From here on out, all we care about is the unqualified form
5130 // of the argument type.
5131 ArgType = ArgType.getUnqualifiedType();
5133 // Try to convert the argument to the parameter's type.
5134 if (Context.hasSameType(ParamType, ArgType)) {
5135 // Okay: no conversion necessary
5136 } else if (ParamType->isBooleanType()) {
5137 // This is an integral-to-boolean conversion.
5138 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralToBoolean).get();
5139 } else if (IsIntegralPromotion(Arg, ArgType, ParamType) ||
5140 !ParamType->isEnumeralType()) {
5141 // This is an integral promotion or conversion.
5142 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralCast).get();
5144 // We can't perform this conversion.
5145 Diag(Arg->getLocStart(),
5146 diag::err_template_arg_not_convertible)
5147 << Arg->getType() << ParamType << Arg->getSourceRange();
5148 Diag(Param->getLocation(), diag::note_template_param_here);
5152 // Add the value of this argument to the list of converted
5153 // arguments. We use the bitwidth and signedness of the template
5155 if (Arg->isValueDependent()) {
5156 // The argument is value-dependent. Create a new
5157 // TemplateArgument with the converted expression.
5158 Converted = TemplateArgument(Arg);
5162 QualType IntegerType = Context.getCanonicalType(ParamType);
5163 if (const EnumType *Enum = IntegerType->getAs<EnumType>())
5164 IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType());
5166 if (ParamType->isBooleanType()) {
5167 // Value must be zero or one.
5169 unsigned AllowedBits = Context.getTypeSize(IntegerType);
5170 if (Value.getBitWidth() != AllowedBits)
5171 Value = Value.extOrTrunc(AllowedBits);
5172 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
5174 llvm::APSInt OldValue = Value;
5176 // Coerce the template argument's value to the value it will have
5177 // based on the template parameter's type.
5178 unsigned AllowedBits = Context.getTypeSize(IntegerType);
5179 if (Value.getBitWidth() != AllowedBits)
5180 Value = Value.extOrTrunc(AllowedBits);
5181 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
5183 // Complain if an unsigned parameter received a negative value.
5184 if (IntegerType->isUnsignedIntegerOrEnumerationType()
5185 && (OldValue.isSigned() && OldValue.isNegative())) {
5186 Diag(Arg->getLocStart(), diag::warn_template_arg_negative)
5187 << OldValue.toString(10) << Value.toString(10) << Param->getType()
5188 << Arg->getSourceRange();
5189 Diag(Param->getLocation(), diag::note_template_param_here);
5192 // Complain if we overflowed the template parameter's type.
5193 unsigned RequiredBits;
5194 if (IntegerType->isUnsignedIntegerOrEnumerationType())
5195 RequiredBits = OldValue.getActiveBits();
5196 else if (OldValue.isUnsigned())
5197 RequiredBits = OldValue.getActiveBits() + 1;
5199 RequiredBits = OldValue.getMinSignedBits();
5200 if (RequiredBits > AllowedBits) {
5201 Diag(Arg->getLocStart(),
5202 diag::warn_template_arg_too_large)
5203 << OldValue.toString(10) << Value.toString(10) << Param->getType()
5204 << Arg->getSourceRange();
5205 Diag(Param->getLocation(), diag::note_template_param_here);
5209 Converted = TemplateArgument(Context, Value,
5210 ParamType->isEnumeralType()
5211 ? Context.getCanonicalType(ParamType)
5216 QualType ArgType = Arg->getType();
5217 DeclAccessPair FoundResult; // temporary for ResolveOverloadedFunction
5219 // Handle pointer-to-function, reference-to-function, and
5220 // pointer-to-member-function all in (roughly) the same way.
5221 if (// -- For a non-type template-parameter of type pointer to
5222 // function, only the function-to-pointer conversion (4.3) is
5223 // applied. If the template-argument represents a set of
5224 // overloaded functions (or a pointer to such), the matching
5225 // function is selected from the set (13.4).
5226 (ParamType->isPointerType() &&
5227 ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType()) ||
5228 // -- For a non-type template-parameter of type reference to
5229 // function, no conversions apply. If the template-argument
5230 // represents a set of overloaded functions, the matching
5231 // function is selected from the set (13.4).
5232 (ParamType->isReferenceType() &&
5233 ParamType->getAs<ReferenceType>()->getPointeeType()->isFunctionType()) ||
5234 // -- For a non-type template-parameter of type pointer to
5235 // member function, no conversions apply. If the
5236 // template-argument represents a set of overloaded member
5237 // functions, the matching member function is selected from
5239 (ParamType->isMemberPointerType() &&
5240 ParamType->getAs<MemberPointerType>()->getPointeeType()
5241 ->isFunctionType())) {
5243 if (Arg->getType() == Context.OverloadTy) {
5244 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType,
5247 if (DiagnoseUseOfDecl(Fn, Arg->getLocStart()))
5250 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
5251 ArgType = Arg->getType();
5256 if (!ParamType->isMemberPointerType()) {
5257 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5264 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
5270 if (ParamType->isPointerType()) {
5271 // -- for a non-type template-parameter of type pointer to
5272 // object, qualification conversions (4.4) and the
5273 // array-to-pointer conversion (4.2) are applied.
5274 // C++0x also allows a value of std::nullptr_t.
5275 assert(ParamType->getPointeeType()->isIncompleteOrObjectType() &&
5276 "Only object pointers allowed here");
5278 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5285 if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) {
5286 // -- For a non-type template-parameter of type reference to
5287 // object, no conversions apply. The type referred to by the
5288 // reference may be more cv-qualified than the (otherwise
5289 // identical) type of the template-argument. The
5290 // template-parameter is bound directly to the
5291 // template-argument, which must be an lvalue.
5292 assert(ParamRefType->getPointeeType()->isIncompleteOrObjectType() &&
5293 "Only object references allowed here");
5295 if (Arg->getType() == Context.OverloadTy) {
5296 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg,
5297 ParamRefType->getPointeeType(),
5300 if (DiagnoseUseOfDecl(Fn, Arg->getLocStart()))
5303 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
5304 ArgType = Arg->getType();
5309 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
5316 // Deal with parameters of type std::nullptr_t.
5317 if (ParamType->isNullPtrType()) {
5318 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
5319 Converted = TemplateArgument(Arg);
5323 switch (isNullPointerValueTemplateArgument(*this, Param, ParamType, Arg)) {
5324 case NPV_NotNullPointer:
5325 Diag(Arg->getExprLoc(), diag::err_template_arg_not_convertible)
5326 << Arg->getType() << ParamType;
5327 Diag(Param->getLocation(), diag::note_template_param_here);
5333 case NPV_NullPointer:
5334 Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
5335 Converted = TemplateArgument(Context.getCanonicalType(ParamType),
5341 // -- For a non-type template-parameter of type pointer to data
5342 // member, qualification conversions (4.4) are applied.
5343 assert(ParamType->isMemberPointerType() && "Only pointers to members remain");
5345 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
5351 /// \brief Check a template argument against its corresponding
5352 /// template template parameter.
5354 /// This routine implements the semantics of C++ [temp.arg.template].
5355 /// It returns true if an error occurred, and false otherwise.
5356 bool Sema::CheckTemplateArgument(TemplateTemplateParmDecl *Param,
5357 TemplateArgumentLoc &Arg,
5358 unsigned ArgumentPackIndex) {
5359 TemplateName Name = Arg.getArgument().getAsTemplateOrTemplatePattern();
5360 TemplateDecl *Template = Name.getAsTemplateDecl();
5362 // Any dependent template name is fine.
5363 assert(Name.isDependent() && "Non-dependent template isn't a declaration?");
5367 // C++0x [temp.arg.template]p1:
5368 // A template-argument for a template template-parameter shall be
5369 // the name of a class template or an alias template, expressed as an
5370 // id-expression. When the template-argument names a class template, only
5371 // primary class templates are considered when matching the
5372 // template template argument with the corresponding parameter;
5373 // partial specializations are not considered even if their
5374 // parameter lists match that of the template template parameter.
5376 // Note that we also allow template template parameters here, which
5377 // will happen when we are dealing with, e.g., class template
5378 // partial specializations.
5379 if (!isa<ClassTemplateDecl>(Template) &&
5380 !isa<TemplateTemplateParmDecl>(Template) &&
5381 !isa<TypeAliasTemplateDecl>(Template)) {
5382 assert(isa<FunctionTemplateDecl>(Template) &&
5383 "Only function templates are possible here");
5384 Diag(Arg.getLocation(), diag::err_template_arg_not_valid_template);
5385 Diag(Template->getLocation(), diag::note_template_arg_refers_here_func)
5389 TemplateParameterList *Params = Param->getTemplateParameters();
5390 if (Param->isExpandedParameterPack())
5391 Params = Param->getExpansionTemplateParameters(ArgumentPackIndex);
5393 return !TemplateParameterListsAreEqual(Template->getTemplateParameters(),
5396 TPL_TemplateTemplateArgumentMatch,
5400 /// \brief Given a non-type template argument that refers to a
5401 /// declaration and the type of its corresponding non-type template
5402 /// parameter, produce an expression that properly refers to that
5405 Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
5407 SourceLocation Loc) {
5408 // C++ [temp.param]p8:
5410 // A non-type template-parameter of type "array of T" or
5411 // "function returning T" is adjusted to be of type "pointer to
5412 // T" or "pointer to function returning T", respectively.
5413 if (ParamType->isArrayType())
5414 ParamType = Context.getArrayDecayedType(ParamType);
5415 else if (ParamType->isFunctionType())
5416 ParamType = Context.getPointerType(ParamType);
5418 // For a NULL non-type template argument, return nullptr casted to the
5419 // parameter's type.
5420 if (Arg.getKind() == TemplateArgument::NullPtr) {
5421 return ImpCastExprToType(
5422 new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc),
5424 ParamType->getAs<MemberPointerType>()
5425 ? CK_NullToMemberPointer
5426 : CK_NullToPointer);
5428 assert(Arg.getKind() == TemplateArgument::Declaration &&
5429 "Only declaration template arguments permitted here");
5431 ValueDecl *VD = cast<ValueDecl>(Arg.getAsDecl());
5433 if (VD->getDeclContext()->isRecord() &&
5434 (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD) ||
5435 isa<IndirectFieldDecl>(VD))) {
5436 // If the value is a class member, we might have a pointer-to-member.
5437 // Determine whether the non-type template template parameter is of
5438 // pointer-to-member type. If so, we need to build an appropriate
5439 // expression for a pointer-to-member, since a "normal" DeclRefExpr
5440 // would refer to the member itself.
5441 if (ParamType->isMemberPointerType()) {
5443 = Context.getTypeDeclType(cast<RecordDecl>(VD->getDeclContext()));
5444 NestedNameSpecifier *Qualifier
5445 = NestedNameSpecifier::Create(Context, nullptr, false,
5446 ClassType.getTypePtr());
5448 SS.MakeTrivial(Context, Qualifier, Loc);
5450 // The actual value-ness of this is unimportant, but for
5451 // internal consistency's sake, references to instance methods
5453 ExprValueKind VK = VK_LValue;
5454 if (isa<CXXMethodDecl>(VD) && cast<CXXMethodDecl>(VD)->isInstance())
5457 ExprResult RefExpr = BuildDeclRefExpr(VD,
5458 VD->getType().getNonReferenceType(),
5462 if (RefExpr.isInvalid())
5465 RefExpr = CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
5467 // We might need to perform a trailing qualification conversion, since
5468 // the element type on the parameter could be more qualified than the
5469 // element type in the expression we constructed.
5470 bool ObjCLifetimeConversion;
5471 if (IsQualificationConversion(((Expr*) RefExpr.get())->getType(),
5472 ParamType.getUnqualifiedType(), false,
5473 ObjCLifetimeConversion))
5474 RefExpr = ImpCastExprToType(RefExpr.get(), ParamType.getUnqualifiedType(), CK_NoOp);
5476 assert(!RefExpr.isInvalid() &&
5477 Context.hasSameType(((Expr*) RefExpr.get())->getType(),
5478 ParamType.getUnqualifiedType()));
5483 QualType T = VD->getType().getNonReferenceType();
5485 if (ParamType->isPointerType()) {
5486 // When the non-type template parameter is a pointer, take the
5487 // address of the declaration.
5488 ExprResult RefExpr = BuildDeclRefExpr(VD, T, VK_LValue, Loc);
5489 if (RefExpr.isInvalid())
5492 if (T->isFunctionType() || T->isArrayType()) {
5493 // Decay functions and arrays.
5494 RefExpr = DefaultFunctionArrayConversion(RefExpr.get());
5495 if (RefExpr.isInvalid())
5501 // Take the address of everything else
5502 return CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
5505 ExprValueKind VK = VK_RValue;
5507 // If the non-type template parameter has reference type, qualify the
5508 // resulting declaration reference with the extra qualifiers on the
5509 // type that the reference refers to.
5510 if (const ReferenceType *TargetRef = ParamType->getAs<ReferenceType>()) {
5512 T = Context.getQualifiedType(T,
5513 TargetRef->getPointeeType().getQualifiers());
5514 } else if (isa<FunctionDecl>(VD)) {
5515 // References to functions are always lvalues.
5519 return BuildDeclRefExpr(VD, T, VK, Loc);
5522 /// \brief Construct a new expression that refers to the given
5523 /// integral template argument with the given source-location
5526 /// This routine takes care of the mapping from an integral template
5527 /// argument (which may have any integral type) to the appropriate
5530 Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg,
5531 SourceLocation Loc) {
5532 assert(Arg.getKind() == TemplateArgument::Integral &&
5533 "Operation is only valid for integral template arguments");
5534 QualType OrigT = Arg.getIntegralType();
5536 // If this is an enum type that we're instantiating, we need to use an integer
5537 // type the same size as the enumerator. We don't want to build an
5538 // IntegerLiteral with enum type. The integer type of an enum type can be of
5539 // any integral type with C++11 enum classes, make sure we create the right
5540 // type of literal for it.
5542 if (const EnumType *ET = OrigT->getAs<EnumType>())
5543 T = ET->getDecl()->getIntegerType();
5546 if (T->isAnyCharacterType()) {
5547 // This does not need to handle u8 character literals because those are
5548 // of type char, and so can also be covered by an ASCII character literal.
5549 CharacterLiteral::CharacterKind Kind;
5550 if (T->isWideCharType())
5551 Kind = CharacterLiteral::Wide;
5552 else if (T->isChar16Type())
5553 Kind = CharacterLiteral::UTF16;
5554 else if (T->isChar32Type())
5555 Kind = CharacterLiteral::UTF32;
5557 Kind = CharacterLiteral::Ascii;
5559 E = new (Context) CharacterLiteral(Arg.getAsIntegral().getZExtValue(),
5561 } else if (T->isBooleanType()) {
5562 E = new (Context) CXXBoolLiteralExpr(Arg.getAsIntegral().getBoolValue(),
5564 } else if (T->isNullPtrType()) {
5565 E = new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
5567 E = IntegerLiteral::Create(Context, Arg.getAsIntegral(), T, Loc);
5570 if (OrigT->isEnumeralType()) {
5571 // FIXME: This is a hack. We need a better way to handle substituted
5572 // non-type template parameters.
5573 E = CStyleCastExpr::Create(Context, OrigT, VK_RValue, CK_IntegralCast, E,
5575 Context.getTrivialTypeSourceInfo(OrigT, Loc),
5582 /// \brief Match two template parameters within template parameter lists.
5583 static bool MatchTemplateParameterKind(Sema &S, NamedDecl *New, NamedDecl *Old,
5585 Sema::TemplateParameterListEqualKind Kind,
5586 SourceLocation TemplateArgLoc) {
5587 // Check the actual kind (type, non-type, template).
5588 if (Old->getKind() != New->getKind()) {
5590 unsigned NextDiag = diag::err_template_param_different_kind;
5591 if (TemplateArgLoc.isValid()) {
5592 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
5593 NextDiag = diag::note_template_param_different_kind;
5595 S.Diag(New->getLocation(), NextDiag)
5596 << (Kind != Sema::TPL_TemplateMatch);
5597 S.Diag(Old->getLocation(), diag::note_template_prev_declaration)
5598 << (Kind != Sema::TPL_TemplateMatch);
5604 // Check that both are parameter packs are neither are parameter packs.
5605 // However, if we are matching a template template argument to a
5606 // template template parameter, the template template parameter can have
5607 // a parameter pack where the template template argument does not.
5608 if (Old->isTemplateParameterPack() != New->isTemplateParameterPack() &&
5609 !(Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
5610 Old->isTemplateParameterPack())) {
5612 unsigned NextDiag = diag::err_template_parameter_pack_non_pack;
5613 if (TemplateArgLoc.isValid()) {
5614 S.Diag(TemplateArgLoc,
5615 diag::err_template_arg_template_params_mismatch);
5616 NextDiag = diag::note_template_parameter_pack_non_pack;
5619 unsigned ParamKind = isa<TemplateTypeParmDecl>(New)? 0
5620 : isa<NonTypeTemplateParmDecl>(New)? 1
5622 S.Diag(New->getLocation(), NextDiag)
5623 << ParamKind << New->isParameterPack();
5624 S.Diag(Old->getLocation(), diag::note_template_parameter_pack_here)
5625 << ParamKind << Old->isParameterPack();
5631 // For non-type template parameters, check the type of the parameter.
5632 if (NonTypeTemplateParmDecl *OldNTTP
5633 = dyn_cast<NonTypeTemplateParmDecl>(Old)) {
5634 NonTypeTemplateParmDecl *NewNTTP = cast<NonTypeTemplateParmDecl>(New);
5636 // If we are matching a template template argument to a template
5637 // template parameter and one of the non-type template parameter types
5638 // is dependent, then we must wait until template instantiation time
5639 // to actually compare the arguments.
5640 if (Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
5641 (OldNTTP->getType()->isDependentType() ||
5642 NewNTTP->getType()->isDependentType()))
5645 if (!S.Context.hasSameType(OldNTTP->getType(), NewNTTP->getType())) {
5647 unsigned NextDiag = diag::err_template_nontype_parm_different_type;
5648 if (TemplateArgLoc.isValid()) {
5649 S.Diag(TemplateArgLoc,
5650 diag::err_template_arg_template_params_mismatch);
5651 NextDiag = diag::note_template_nontype_parm_different_type;
5653 S.Diag(NewNTTP->getLocation(), NextDiag)
5654 << NewNTTP->getType()
5655 << (Kind != Sema::TPL_TemplateMatch);
5656 S.Diag(OldNTTP->getLocation(),
5657 diag::note_template_nontype_parm_prev_declaration)
5658 << OldNTTP->getType();
5667 // For template template parameters, check the template parameter types.
5668 // The template parameter lists of template template
5669 // parameters must agree.
5670 if (TemplateTemplateParmDecl *OldTTP
5671 = dyn_cast<TemplateTemplateParmDecl>(Old)) {
5672 TemplateTemplateParmDecl *NewTTP = cast<TemplateTemplateParmDecl>(New);
5673 return S.TemplateParameterListsAreEqual(NewTTP->getTemplateParameters(),
5674 OldTTP->getTemplateParameters(),
5676 (Kind == Sema::TPL_TemplateMatch
5677 ? Sema::TPL_TemplateTemplateParmMatch
5685 /// \brief Diagnose a known arity mismatch when comparing template argument
5688 void DiagnoseTemplateParameterListArityMismatch(Sema &S,
5689 TemplateParameterList *New,
5690 TemplateParameterList *Old,
5691 Sema::TemplateParameterListEqualKind Kind,
5692 SourceLocation TemplateArgLoc) {
5693 unsigned NextDiag = diag::err_template_param_list_different_arity;
5694 if (TemplateArgLoc.isValid()) {
5695 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
5696 NextDiag = diag::note_template_param_list_different_arity;
5698 S.Diag(New->getTemplateLoc(), NextDiag)
5699 << (New->size() > Old->size())
5700 << (Kind != Sema::TPL_TemplateMatch)
5701 << SourceRange(New->getTemplateLoc(), New->getRAngleLoc());
5702 S.Diag(Old->getTemplateLoc(), diag::note_template_prev_declaration)
5703 << (Kind != Sema::TPL_TemplateMatch)
5704 << SourceRange(Old->getTemplateLoc(), Old->getRAngleLoc());
5707 /// \brief Determine whether the given template parameter lists are
5710 /// \param New The new template parameter list, typically written in the
5711 /// source code as part of a new template declaration.
5713 /// \param Old The old template parameter list, typically found via
5714 /// name lookup of the template declared with this template parameter
5717 /// \param Complain If true, this routine will produce a diagnostic if
5718 /// the template parameter lists are not equivalent.
5720 /// \param Kind describes how we are to match the template parameter lists.
5722 /// \param TemplateArgLoc If this source location is valid, then we
5723 /// are actually checking the template parameter list of a template
5724 /// argument (New) against the template parameter list of its
5725 /// corresponding template template parameter (Old). We produce
5726 /// slightly different diagnostics in this scenario.
5728 /// \returns True if the template parameter lists are equal, false
5731 Sema::TemplateParameterListsAreEqual(TemplateParameterList *New,
5732 TemplateParameterList *Old,
5734 TemplateParameterListEqualKind Kind,
5735 SourceLocation TemplateArgLoc) {
5736 if (Old->size() != New->size() && Kind != TPL_TemplateTemplateArgumentMatch) {
5738 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
5744 // C++0x [temp.arg.template]p3:
5745 // A template-argument matches a template template-parameter (call it P)
5746 // when each of the template parameters in the template-parameter-list of
5747 // the template-argument's corresponding class template or alias template
5748 // (call it A) matches the corresponding template parameter in the
5749 // template-parameter-list of P. [...]
5750 TemplateParameterList::iterator NewParm = New->begin();
5751 TemplateParameterList::iterator NewParmEnd = New->end();
5752 for (TemplateParameterList::iterator OldParm = Old->begin(),
5753 OldParmEnd = Old->end();
5754 OldParm != OldParmEnd; ++OldParm) {
5755 if (Kind != TPL_TemplateTemplateArgumentMatch ||
5756 !(*OldParm)->isTemplateParameterPack()) {
5757 if (NewParm == NewParmEnd) {
5759 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
5765 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
5766 Kind, TemplateArgLoc))
5773 // C++0x [temp.arg.template]p3:
5774 // [...] When P's template- parameter-list contains a template parameter
5775 // pack (14.5.3), the template parameter pack will match zero or more
5776 // template parameters or template parameter packs in the
5777 // template-parameter-list of A with the same type and form as the
5778 // template parameter pack in P (ignoring whether those template
5779 // parameters are template parameter packs).
5780 for (; NewParm != NewParmEnd; ++NewParm) {
5781 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
5782 Kind, TemplateArgLoc))
5787 // Make sure we exhausted all of the arguments.
5788 if (NewParm != NewParmEnd) {
5790 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
5799 /// \brief Check whether a template can be declared within this scope.
5801 /// If the template declaration is valid in this scope, returns
5802 /// false. Otherwise, issues a diagnostic and returns true.
5804 Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) {
5808 // Find the nearest enclosing declaration scope.
5809 while ((S->getFlags() & Scope::DeclScope) == 0 ||
5810 (S->getFlags() & Scope::TemplateParamScope) != 0)
5814 // A template [...] shall not have C linkage.
5815 DeclContext *Ctx = S->getEntity();
5816 if (Ctx && Ctx->isExternCContext())
5817 return Diag(TemplateParams->getTemplateLoc(), diag::err_template_linkage)
5818 << TemplateParams->getSourceRange();
5820 while (Ctx && isa<LinkageSpecDecl>(Ctx))
5821 Ctx = Ctx->getParent();
5824 // A template-declaration can appear only as a namespace scope or
5825 // class scope declaration.
5827 if (Ctx->isFileContext())
5829 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Ctx)) {
5830 // C++ [temp.mem]p2:
5831 // A local class shall not have member templates.
5832 if (RD->isLocalClass())
5833 return Diag(TemplateParams->getTemplateLoc(),
5834 diag::err_template_inside_local_class)
5835 << TemplateParams->getSourceRange();
5841 return Diag(TemplateParams->getTemplateLoc(),
5842 diag::err_template_outside_namespace_or_class_scope)
5843 << TemplateParams->getSourceRange();
5846 /// \brief Determine what kind of template specialization the given declaration
5848 static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D) {
5850 return TSK_Undeclared;
5852 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D))
5853 return Record->getTemplateSpecializationKind();
5854 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D))
5855 return Function->getTemplateSpecializationKind();
5856 if (VarDecl *Var = dyn_cast<VarDecl>(D))
5857 return Var->getTemplateSpecializationKind();
5859 return TSK_Undeclared;
5862 /// \brief Check whether a specialization is well-formed in the current
5865 /// This routine determines whether a template specialization can be declared
5866 /// in the current context (C++ [temp.expl.spec]p2).
5868 /// \param S the semantic analysis object for which this check is being
5871 /// \param Specialized the entity being specialized or instantiated, which
5872 /// may be a kind of template (class template, function template, etc.) or
5873 /// a member of a class template (member function, static data member,
5876 /// \param PrevDecl the previous declaration of this entity, if any.
5878 /// \param Loc the location of the explicit specialization or instantiation of
5881 /// \param IsPartialSpecialization whether this is a partial specialization of
5882 /// a class template.
5884 /// \returns true if there was an error that we cannot recover from, false
5886 static bool CheckTemplateSpecializationScope(Sema &S,
5887 NamedDecl *Specialized,
5888 NamedDecl *PrevDecl,
5890 bool IsPartialSpecialization) {
5891 // Keep these "kind" numbers in sync with the %select statements in the
5892 // various diagnostics emitted by this routine.
5894 if (isa<ClassTemplateDecl>(Specialized))
5895 EntityKind = IsPartialSpecialization? 1 : 0;
5896 else if (isa<VarTemplateDecl>(Specialized))
5897 EntityKind = IsPartialSpecialization ? 3 : 2;
5898 else if (isa<FunctionTemplateDecl>(Specialized))
5900 else if (isa<CXXMethodDecl>(Specialized))
5902 else if (isa<VarDecl>(Specialized))
5904 else if (isa<RecordDecl>(Specialized))
5906 else if (isa<EnumDecl>(Specialized) && S.getLangOpts().CPlusPlus11)
5909 S.Diag(Loc, diag::err_template_spec_unknown_kind)
5910 << S.getLangOpts().CPlusPlus11;
5911 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
5915 // C++ [temp.expl.spec]p2:
5916 // An explicit specialization shall be declared in the namespace
5917 // of which the template is a member, or, for member templates, in
5918 // the namespace of which the enclosing class or enclosing class
5919 // template is a member. An explicit specialization of a member
5920 // function, member class or static data member of a class
5921 // template shall be declared in the namespace of which the class
5922 // template is a member. Such a declaration may also be a
5923 // definition. If the declaration is not a definition, the
5924 // specialization may be defined later in the name- space in which
5925 // the explicit specialization was declared, or in a namespace
5926 // that encloses the one in which the explicit specialization was
5928 if (S.CurContext->getRedeclContext()->isFunctionOrMethod()) {
5929 S.Diag(Loc, diag::err_template_spec_decl_function_scope)
5934 if (S.CurContext->isRecord() && !IsPartialSpecialization) {
5935 if (S.getLangOpts().MicrosoftExt) {
5936 // Do not warn for class scope explicit specialization during
5937 // instantiation, warning was already emitted during pattern
5938 // semantic analysis.
5939 if (!S.ActiveTemplateInstantiations.size())
5940 S.Diag(Loc, diag::ext_function_specialization_in_class)
5943 S.Diag(Loc, diag::err_template_spec_decl_class_scope)
5949 if (S.CurContext->isRecord() &&
5950 !S.CurContext->Equals(Specialized->getDeclContext())) {
5951 // Make sure that we're specializing in the right record context.
5952 // Otherwise, things can go horribly wrong.
5953 S.Diag(Loc, diag::err_template_spec_decl_class_scope)
5958 // C++ [temp.class.spec]p6:
5959 // A class template partial specialization may be declared or redeclared
5960 // in any namespace scope in which its definition may be defined (14.5.1
5962 DeclContext *SpecializedContext
5963 = Specialized->getDeclContext()->getEnclosingNamespaceContext();
5964 DeclContext *DC = S.CurContext->getEnclosingNamespaceContext();
5966 // Make sure that this redeclaration (or definition) occurs in an enclosing
5968 // Note that HandleDeclarator() performs this check for explicit
5969 // specializations of function templates, static data members, and member
5970 // functions, so we skip the check here for those kinds of entities.
5971 // FIXME: HandleDeclarator's diagnostics aren't quite as good, though.
5972 // Should we refactor that check, so that it occurs later?
5973 if (!DC->Encloses(SpecializedContext) &&
5974 !(isa<FunctionTemplateDecl>(Specialized) ||
5975 isa<FunctionDecl>(Specialized) ||
5976 isa<VarTemplateDecl>(Specialized) ||
5977 isa<VarDecl>(Specialized))) {
5978 if (isa<TranslationUnitDecl>(SpecializedContext))
5979 S.Diag(Loc, diag::err_template_spec_redecl_global_scope)
5980 << EntityKind << Specialized;
5981 else if (isa<NamespaceDecl>(SpecializedContext)) {
5982 int Diag = diag::err_template_spec_redecl_out_of_scope;
5983 if (S.getLangOpts().MicrosoftExt)
5984 Diag = diag::ext_ms_template_spec_redecl_out_of_scope;
5985 S.Diag(Loc, Diag) << EntityKind << Specialized
5986 << cast<NamedDecl>(SpecializedContext);
5988 llvm_unreachable("unexpected namespace context for specialization");
5990 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
5991 } else if ((!PrevDecl ||
5992 getTemplateSpecializationKind(PrevDecl) == TSK_Undeclared ||
5993 getTemplateSpecializationKind(PrevDecl) ==
5994 TSK_ImplicitInstantiation)) {
5995 // C++ [temp.exp.spec]p2:
5996 // An explicit specialization shall be declared in the namespace of which
5997 // the template is a member, or, for member templates, in the namespace
5998 // of which the enclosing class or enclosing class template is a member.
5999 // An explicit specialization of a member function, member class or
6000 // static data member of a class template shall be declared in the
6001 // namespace of which the class template is a member.
6003 // C++11 [temp.expl.spec]p2:
6004 // An explicit specialization shall be declared in a namespace enclosing
6005 // the specialized template.
6006 // C++11 [temp.explicit]p3:
6007 // An explicit instantiation shall appear in an enclosing namespace of its
6009 if (!DC->InEnclosingNamespaceSetOf(SpecializedContext)) {
6010 bool IsCPlusPlus11Extension = DC->Encloses(SpecializedContext);
6011 if (isa<TranslationUnitDecl>(SpecializedContext)) {
6012 assert(!IsCPlusPlus11Extension &&
6013 "DC encloses TU but isn't in enclosing namespace set");
6014 S.Diag(Loc, diag::err_template_spec_decl_out_of_scope_global)
6015 << EntityKind << Specialized;
6016 } else if (isa<NamespaceDecl>(SpecializedContext)) {
6018 if (!IsCPlusPlus11Extension)
6019 Diag = diag::err_template_spec_decl_out_of_scope;
6020 else if (!S.getLangOpts().CPlusPlus11)
6021 Diag = diag::ext_template_spec_decl_out_of_scope;
6023 Diag = diag::warn_cxx98_compat_template_spec_decl_out_of_scope;
6025 << EntityKind << Specialized << cast<NamedDecl>(SpecializedContext);
6028 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
6035 static SourceRange findTemplateParameter(unsigned Depth, Expr *E) {
6036 if (!E->isInstantiationDependent())
6037 return SourceLocation();
6038 DependencyChecker Checker(Depth);
6039 Checker.TraverseStmt(E);
6040 if (Checker.Match && Checker.MatchLoc.isInvalid())
6041 return E->getSourceRange();
6042 return Checker.MatchLoc;
6045 static SourceRange findTemplateParameter(unsigned Depth, TypeLoc TL) {
6046 if (!TL.getType()->isDependentType())
6047 return SourceLocation();
6048 DependencyChecker Checker(Depth);
6049 Checker.TraverseTypeLoc(TL);
6050 if (Checker.Match && Checker.MatchLoc.isInvalid())
6051 return TL.getSourceRange();
6052 return Checker.MatchLoc;
6055 /// \brief Subroutine of Sema::CheckTemplatePartialSpecializationArgs
6056 /// that checks non-type template partial specialization arguments.
6057 static bool CheckNonTypeTemplatePartialSpecializationArgs(
6058 Sema &S, SourceLocation TemplateNameLoc, NonTypeTemplateParmDecl *Param,
6059 const TemplateArgument *Args, unsigned NumArgs, bool IsDefaultArgument) {
6060 for (unsigned I = 0; I != NumArgs; ++I) {
6061 if (Args[I].getKind() == TemplateArgument::Pack) {
6062 if (CheckNonTypeTemplatePartialSpecializationArgs(
6063 S, TemplateNameLoc, Param, Args[I].pack_begin(),
6064 Args[I].pack_size(), IsDefaultArgument))
6070 if (Args[I].getKind() != TemplateArgument::Expression)
6073 Expr *ArgExpr = Args[I].getAsExpr();
6075 // We can have a pack expansion of any of the bullets below.
6076 if (PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(ArgExpr))
6077 ArgExpr = Expansion->getPattern();
6079 // Strip off any implicit casts we added as part of type checking.
6080 while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
6081 ArgExpr = ICE->getSubExpr();
6083 // C++ [temp.class.spec]p8:
6084 // A non-type argument is non-specialized if it is the name of a
6085 // non-type parameter. All other non-type arguments are
6088 // Below, we check the two conditions that only apply to
6089 // specialized non-type arguments, so skip any non-specialized
6091 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ArgExpr))
6092 if (isa<NonTypeTemplateParmDecl>(DRE->getDecl()))
6095 // C++ [temp.class.spec]p9:
6096 // Within the argument list of a class template partial
6097 // specialization, the following restrictions apply:
6098 // -- A partially specialized non-type argument expression
6099 // shall not involve a template parameter of the partial
6100 // specialization except when the argument expression is a
6101 // simple identifier.
6102 SourceRange ParamUseRange =
6103 findTemplateParameter(Param->getDepth(), ArgExpr);
6104 if (ParamUseRange.isValid()) {
6105 if (IsDefaultArgument) {
6106 S.Diag(TemplateNameLoc,
6107 diag::err_dependent_non_type_arg_in_partial_spec);
6108 S.Diag(ParamUseRange.getBegin(),
6109 diag::note_dependent_non_type_default_arg_in_partial_spec)
6112 S.Diag(ParamUseRange.getBegin(),
6113 diag::err_dependent_non_type_arg_in_partial_spec)
6119 // -- The type of a template parameter corresponding to a
6120 // specialized non-type argument shall not be dependent on a
6121 // parameter of the specialization.
6123 // FIXME: We need to delay this check until instantiation in some cases:
6125 // template<template<typename> class X> struct A {
6126 // template<typename T, X<T> N> struct B;
6127 // template<typename T> struct B<T, 0>;
6129 // template<typename> using X = int;
6130 // A<X>::B<int, 0> b;
6131 ParamUseRange = findTemplateParameter(
6132 Param->getDepth(), Param->getTypeSourceInfo()->getTypeLoc());
6133 if (ParamUseRange.isValid()) {
6134 S.Diag(IsDefaultArgument ? TemplateNameLoc : ArgExpr->getLocStart(),
6135 diag::err_dependent_typed_non_type_arg_in_partial_spec)
6136 << Param->getType() << ParamUseRange;
6137 S.Diag(Param->getLocation(), diag::note_template_param_here)
6138 << (IsDefaultArgument ? ParamUseRange : SourceRange());
6146 /// \brief Check the non-type template arguments of a class template
6147 /// partial specialization according to C++ [temp.class.spec]p9.
6149 /// \param TemplateNameLoc the location of the template name.
6150 /// \param TemplateParams the template parameters of the primary class
6152 /// \param NumExplicit the number of explicitly-specified template arguments.
6153 /// \param TemplateArgs the template arguments of the class template
6154 /// partial specialization.
6156 /// \returns \c true if there was an error, \c false otherwise.
6157 static bool CheckTemplatePartialSpecializationArgs(
6158 Sema &S, SourceLocation TemplateNameLoc,
6159 TemplateParameterList *TemplateParams, unsigned NumExplicit,
6160 SmallVectorImpl<TemplateArgument> &TemplateArgs) {
6161 const TemplateArgument *ArgList = TemplateArgs.data();
6163 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
6164 NonTypeTemplateParmDecl *Param
6165 = dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(I));
6169 if (CheckNonTypeTemplatePartialSpecializationArgs(
6170 S, TemplateNameLoc, Param, &ArgList[I], 1, I >= NumExplicit))
6178 Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec,
6180 SourceLocation KWLoc,
6181 SourceLocation ModulePrivateLoc,
6182 TemplateIdAnnotation &TemplateId,
6183 AttributeList *Attr,
6184 MultiTemplateParamsArg
6185 TemplateParameterLists,
6186 SkipBodyInfo *SkipBody) {
6187 assert(TUK != TUK_Reference && "References are not specializations");
6189 CXXScopeSpec &SS = TemplateId.SS;
6191 // NOTE: KWLoc is the location of the tag keyword. This will instead
6192 // store the location of the outermost template keyword in the declaration.
6193 SourceLocation TemplateKWLoc = TemplateParameterLists.size() > 0
6194 ? TemplateParameterLists[0]->getTemplateLoc() : KWLoc;
6195 SourceLocation TemplateNameLoc = TemplateId.TemplateNameLoc;
6196 SourceLocation LAngleLoc = TemplateId.LAngleLoc;
6197 SourceLocation RAngleLoc = TemplateId.RAngleLoc;
6199 // Find the class template we're specializing
6200 TemplateName Name = TemplateId.Template.get();
6201 ClassTemplateDecl *ClassTemplate
6202 = dyn_cast_or_null<ClassTemplateDecl>(Name.getAsTemplateDecl());
6204 if (!ClassTemplate) {
6205 Diag(TemplateNameLoc, diag::err_not_class_template_specialization)
6206 << (Name.getAsTemplateDecl() &&
6207 isa<TemplateTemplateParmDecl>(Name.getAsTemplateDecl()));
6211 bool isExplicitSpecialization = false;
6212 bool isPartialSpecialization = false;
6214 // Check the validity of the template headers that introduce this
6216 // FIXME: We probably shouldn't complain about these headers for
6217 // friend declarations.
6218 bool Invalid = false;
6219 TemplateParameterList *TemplateParams =
6220 MatchTemplateParametersToScopeSpecifier(
6221 KWLoc, TemplateNameLoc, SS, &TemplateId,
6222 TemplateParameterLists, TUK == TUK_Friend, isExplicitSpecialization,
6227 if (TemplateParams && TemplateParams->size() > 0) {
6228 isPartialSpecialization = true;
6230 if (TUK == TUK_Friend) {
6231 Diag(KWLoc, diag::err_partial_specialization_friend)
6232 << SourceRange(LAngleLoc, RAngleLoc);
6236 // C++ [temp.class.spec]p10:
6237 // The template parameter list of a specialization shall not
6238 // contain default template argument values.
6239 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
6240 Decl *Param = TemplateParams->getParam(I);
6241 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) {
6242 if (TTP->hasDefaultArgument()) {
6243 Diag(TTP->getDefaultArgumentLoc(),
6244 diag::err_default_arg_in_partial_spec);
6245 TTP->removeDefaultArgument();
6247 } else if (NonTypeTemplateParmDecl *NTTP
6248 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
6249 if (Expr *DefArg = NTTP->getDefaultArgument()) {
6250 Diag(NTTP->getDefaultArgumentLoc(),
6251 diag::err_default_arg_in_partial_spec)
6252 << DefArg->getSourceRange();
6253 NTTP->removeDefaultArgument();
6256 TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(Param);
6257 if (TTP->hasDefaultArgument()) {
6258 Diag(TTP->getDefaultArgument().getLocation(),
6259 diag::err_default_arg_in_partial_spec)
6260 << TTP->getDefaultArgument().getSourceRange();
6261 TTP->removeDefaultArgument();
6265 } else if (TemplateParams) {
6266 if (TUK == TUK_Friend)
6267 Diag(KWLoc, diag::err_template_spec_friend)
6268 << FixItHint::CreateRemoval(
6269 SourceRange(TemplateParams->getTemplateLoc(),
6270 TemplateParams->getRAngleLoc()))
6271 << SourceRange(LAngleLoc, RAngleLoc);
6273 isExplicitSpecialization = true;
6275 assert(TUK == TUK_Friend && "should have a 'template<>' for this decl");
6278 // Check that the specialization uses the same tag kind as the
6279 // original template.
6280 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
6281 assert(Kind != TTK_Enum && "Invalid enum tag in class template spec!");
6282 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
6283 Kind, TUK == TUK_Definition, KWLoc,
6284 ClassTemplate->getIdentifier())) {
6285 Diag(KWLoc, diag::err_use_with_wrong_tag)
6287 << FixItHint::CreateReplacement(KWLoc,
6288 ClassTemplate->getTemplatedDecl()->getKindName());
6289 Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
6290 diag::note_previous_use);
6291 Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
6294 // Translate the parser's template argument list in our AST format.
6295 TemplateArgumentListInfo TemplateArgs =
6296 makeTemplateArgumentListInfo(*this, TemplateId);
6298 // Check for unexpanded parameter packs in any of the template arguments.
6299 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
6300 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
6301 UPPC_PartialSpecialization))
6304 // Check that the template argument list is well-formed for this
6306 SmallVector<TemplateArgument, 4> Converted;
6307 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
6308 TemplateArgs, false, Converted))
6311 // Find the class template (partial) specialization declaration that
6312 // corresponds to these arguments.
6313 if (isPartialSpecialization) {
6314 if (CheckTemplatePartialSpecializationArgs(
6315 *this, TemplateNameLoc, ClassTemplate->getTemplateParameters(),
6316 TemplateArgs.size(), Converted))
6319 bool InstantiationDependent;
6320 if (!Name.isDependent() &&
6321 !TemplateSpecializationType::anyDependentTemplateArguments(
6322 TemplateArgs.getArgumentArray(),
6323 TemplateArgs.size(),
6324 InstantiationDependent)) {
6325 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
6326 << ClassTemplate->getDeclName();
6327 isPartialSpecialization = false;
6331 void *InsertPos = nullptr;
6332 ClassTemplateSpecializationDecl *PrevDecl = nullptr;
6334 if (isPartialSpecialization)
6335 // FIXME: Template parameter list matters, too
6336 PrevDecl = ClassTemplate->findPartialSpecialization(Converted, InsertPos);
6338 PrevDecl = ClassTemplate->findSpecialization(Converted, InsertPos);
6340 ClassTemplateSpecializationDecl *Specialization = nullptr;
6342 // Check whether we can declare a class template specialization in
6343 // the current scope.
6344 if (TUK != TUK_Friend &&
6345 CheckTemplateSpecializationScope(*this, ClassTemplate, PrevDecl,
6347 isPartialSpecialization))
6350 // The canonical type
6352 if (isPartialSpecialization) {
6353 // Build the canonical type that describes the converted template
6354 // arguments of the class template partial specialization.
6355 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
6356 CanonType = Context.getTemplateSpecializationType(CanonTemplate,
6360 if (Context.hasSameType(CanonType,
6361 ClassTemplate->getInjectedClassNameSpecialization())) {
6362 // C++ [temp.class.spec]p9b3:
6364 // -- The argument list of the specialization shall not be identical
6365 // to the implicit argument list of the primary template.
6366 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
6367 << /*class template*/0 << (TUK == TUK_Definition)
6368 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
6369 return CheckClassTemplate(S, TagSpec, TUK, KWLoc, SS,
6370 ClassTemplate->getIdentifier(),
6374 AS_none, /*ModulePrivateLoc=*/SourceLocation(),
6375 /*FriendLoc*/SourceLocation(),
6376 TemplateParameterLists.size() - 1,
6377 TemplateParameterLists.data());
6380 // Create a new class template partial specialization declaration node.
6381 ClassTemplatePartialSpecializationDecl *PrevPartial
6382 = cast_or_null<ClassTemplatePartialSpecializationDecl>(PrevDecl);
6383 ClassTemplatePartialSpecializationDecl *Partial
6384 = ClassTemplatePartialSpecializationDecl::Create(Context, Kind,
6385 ClassTemplate->getDeclContext(),
6386 KWLoc, TemplateNameLoc,
6393 SetNestedNameSpecifier(Partial, SS);
6394 if (TemplateParameterLists.size() > 1 && SS.isSet()) {
6395 Partial->setTemplateParameterListsInfo(
6396 Context, TemplateParameterLists.drop_back(1));
6400 ClassTemplate->AddPartialSpecialization(Partial, InsertPos);
6401 Specialization = Partial;
6403 // If we are providing an explicit specialization of a member class
6404 // template specialization, make a note of that.
6405 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
6406 PrevPartial->setMemberSpecialization();
6408 // Check that all of the template parameters of the class template
6409 // partial specialization are deducible from the template
6410 // arguments. If not, this class template partial specialization
6411 // will never be used.
6412 llvm::SmallBitVector DeducibleParams(TemplateParams->size());
6413 MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
6414 TemplateParams->getDepth(),
6417 if (!DeducibleParams.all()) {
6418 unsigned NumNonDeducible = DeducibleParams.size()-DeducibleParams.count();
6419 Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible)
6420 << /*class template*/0 << (NumNonDeducible > 1)
6421 << SourceRange(TemplateNameLoc, RAngleLoc);
6422 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) {
6423 if (!DeducibleParams[I]) {
6424 NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I));
6425 if (Param->getDeclName())
6426 Diag(Param->getLocation(),
6427 diag::note_partial_spec_unused_parameter)
6428 << Param->getDeclName();
6430 Diag(Param->getLocation(),
6431 diag::note_partial_spec_unused_parameter)
6437 // Create a new class template specialization declaration node for
6438 // this explicit specialization or friend declaration.
6440 = ClassTemplateSpecializationDecl::Create(Context, Kind,
6441 ClassTemplate->getDeclContext(),
6442 KWLoc, TemplateNameLoc,
6446 SetNestedNameSpecifier(Specialization, SS);
6447 if (TemplateParameterLists.size() > 0) {
6448 Specialization->setTemplateParameterListsInfo(Context,
6449 TemplateParameterLists);
6453 ClassTemplate->AddSpecialization(Specialization, InsertPos);
6455 if (CurContext->isDependentContext()) {
6456 // -fms-extensions permits specialization of nested classes without
6457 // fully specializing the outer class(es).
6458 assert(getLangOpts().MicrosoftExt &&
6459 "Only possible with -fms-extensions!");
6460 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
6461 CanonType = Context.getTemplateSpecializationType(
6462 CanonTemplate, Converted.data(), Converted.size());
6464 CanonType = Context.getTypeDeclType(Specialization);
6468 // C++ [temp.expl.spec]p6:
6469 // If a template, a member template or the member of a class template is
6470 // explicitly specialized then that specialization shall be declared
6471 // before the first use of that specialization that would cause an implicit
6472 // instantiation to take place, in every translation unit in which such a
6473 // use occurs; no diagnostic is required.
6474 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
6476 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6477 // Is there any previous explicit specialization declaration?
6478 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
6485 SourceRange Range(TemplateNameLoc, RAngleLoc);
6486 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
6487 << Context.getTypeDeclType(Specialization) << Range;
6489 Diag(PrevDecl->getPointOfInstantiation(),
6490 diag::note_instantiation_required_here)
6491 << (PrevDecl->getTemplateSpecializationKind()
6492 != TSK_ImplicitInstantiation);
6497 // If this is not a friend, note that this is an explicit specialization.
6498 if (TUK != TUK_Friend)
6499 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
6501 // Check that this isn't a redefinition of this specialization.
6502 if (TUK == TUK_Definition) {
6503 RecordDecl *Def = Specialization->getDefinition();
6504 NamedDecl *Hidden = nullptr;
6505 if (Def && SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
6506 SkipBody->ShouldSkip = true;
6507 makeMergedDefinitionVisible(Hidden, KWLoc);
6508 // From here on out, treat this as just a redeclaration.
6509 TUK = TUK_Declaration;
6511 SourceRange Range(TemplateNameLoc, RAngleLoc);
6512 Diag(TemplateNameLoc, diag::err_redefinition)
6513 << Context.getTypeDeclType(Specialization) << Range;
6514 Diag(Def->getLocation(), diag::note_previous_definition);
6515 Specialization->setInvalidDecl();
6521 ProcessDeclAttributeList(S, Specialization, Attr);
6523 // Add alignment attributes if necessary; these attributes are checked when
6524 // the ASTContext lays out the structure.
6525 if (TUK == TUK_Definition) {
6526 AddAlignmentAttributesForRecord(Specialization);
6527 AddMsStructLayoutForRecord(Specialization);
6530 if (ModulePrivateLoc.isValid())
6531 Diag(Specialization->getLocation(), diag::err_module_private_specialization)
6532 << (isPartialSpecialization? 1 : 0)
6533 << FixItHint::CreateRemoval(ModulePrivateLoc);
6535 // Build the fully-sugared type for this class template
6536 // specialization as the user wrote in the specialization
6537 // itself. This means that we'll pretty-print the type retrieved
6538 // from the specialization's declaration the way that the user
6539 // actually wrote the specialization, rather than formatting the
6540 // name based on the "canonical" representation used to store the
6541 // template arguments in the specialization.
6542 TypeSourceInfo *WrittenTy
6543 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
6544 TemplateArgs, CanonType);
6545 if (TUK != TUK_Friend) {
6546 Specialization->setTypeAsWritten(WrittenTy);
6547 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
6550 // C++ [temp.expl.spec]p9:
6551 // A template explicit specialization is in the scope of the
6552 // namespace in which the template was defined.
6554 // We actually implement this paragraph where we set the semantic
6555 // context (in the creation of the ClassTemplateSpecializationDecl),
6556 // but we also maintain the lexical context where the actual
6557 // definition occurs.
6558 Specialization->setLexicalDeclContext(CurContext);
6560 // We may be starting the definition of this specialization.
6561 if (TUK == TUK_Definition)
6562 Specialization->startDefinition();
6564 if (TUK == TUK_Friend) {
6565 FriendDecl *Friend = FriendDecl::Create(Context, CurContext,
6569 Friend->setAccess(AS_public);
6570 CurContext->addDecl(Friend);
6572 // Add the specialization into its lexical context, so that it can
6573 // be seen when iterating through the list of declarations in that
6574 // context. However, specializations are not found by name lookup.
6575 CurContext->addDecl(Specialization);
6577 return Specialization;
6580 Decl *Sema::ActOnTemplateDeclarator(Scope *S,
6581 MultiTemplateParamsArg TemplateParameterLists,
6583 Decl *NewDecl = HandleDeclarator(S, D, TemplateParameterLists);
6584 ActOnDocumentableDecl(NewDecl);
6588 /// \brief Strips various properties off an implicit instantiation
6589 /// that has just been explicitly specialized.
6590 static void StripImplicitInstantiation(NamedDecl *D) {
6591 D->dropAttr<DLLImportAttr>();
6592 D->dropAttr<DLLExportAttr>();
6594 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
6595 FD->setInlineSpecified(false);
6598 /// \brief Compute the diagnostic location for an explicit instantiation
6599 // declaration or definition.
6600 static SourceLocation DiagLocForExplicitInstantiation(
6601 NamedDecl* D, SourceLocation PointOfInstantiation) {
6602 // Explicit instantiations following a specialization have no effect and
6603 // hence no PointOfInstantiation. In that case, walk decl backwards
6604 // until a valid name loc is found.
6605 SourceLocation PrevDiagLoc = PointOfInstantiation;
6606 for (Decl *Prev = D; Prev && !PrevDiagLoc.isValid();
6607 Prev = Prev->getPreviousDecl()) {
6608 PrevDiagLoc = Prev->getLocation();
6610 assert(PrevDiagLoc.isValid() &&
6611 "Explicit instantiation without point of instantiation?");
6615 /// \brief Diagnose cases where we have an explicit template specialization
6616 /// before/after an explicit template instantiation, producing diagnostics
6617 /// for those cases where they are required and determining whether the
6618 /// new specialization/instantiation will have any effect.
6620 /// \param NewLoc the location of the new explicit specialization or
6623 /// \param NewTSK the kind of the new explicit specialization or instantiation.
6625 /// \param PrevDecl the previous declaration of the entity.
6627 /// \param PrevTSK the kind of the old explicit specialization or instantiatin.
6629 /// \param PrevPointOfInstantiation if valid, indicates where the previus
6630 /// declaration was instantiated (either implicitly or explicitly).
6632 /// \param HasNoEffect will be set to true to indicate that the new
6633 /// specialization or instantiation has no effect and should be ignored.
6635 /// \returns true if there was an error that should prevent the introduction of
6636 /// the new declaration into the AST, false otherwise.
6638 Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc,
6639 TemplateSpecializationKind NewTSK,
6640 NamedDecl *PrevDecl,
6641 TemplateSpecializationKind PrevTSK,
6642 SourceLocation PrevPointOfInstantiation,
6643 bool &HasNoEffect) {
6644 HasNoEffect = false;
6647 case TSK_Undeclared:
6648 case TSK_ImplicitInstantiation:
6650 (PrevTSK == TSK_Undeclared || PrevTSK == TSK_ImplicitInstantiation) &&
6651 "previous declaration must be implicit!");
6654 case TSK_ExplicitSpecialization:
6656 case TSK_Undeclared:
6657 case TSK_ExplicitSpecialization:
6658 // Okay, we're just specializing something that is either already
6659 // explicitly specialized or has merely been mentioned without any
6663 case TSK_ImplicitInstantiation:
6664 if (PrevPointOfInstantiation.isInvalid()) {
6665 // The declaration itself has not actually been instantiated, so it is
6666 // still okay to specialize it.
6667 StripImplicitInstantiation(PrevDecl);
6672 case TSK_ExplicitInstantiationDeclaration:
6673 case TSK_ExplicitInstantiationDefinition:
6674 assert((PrevTSK == TSK_ImplicitInstantiation ||
6675 PrevPointOfInstantiation.isValid()) &&
6676 "Explicit instantiation without point of instantiation?");
6678 // C++ [temp.expl.spec]p6:
6679 // If a template, a member template or the member of a class template
6680 // is explicitly specialized then that specialization shall be declared
6681 // before the first use of that specialization that would cause an
6682 // implicit instantiation to take place, in every translation unit in
6683 // which such a use occurs; no diagnostic is required.
6684 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6685 // Is there any previous explicit specialization declaration?
6686 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization)
6690 Diag(NewLoc, diag::err_specialization_after_instantiation)
6692 Diag(PrevPointOfInstantiation, diag::note_instantiation_required_here)
6693 << (PrevTSK != TSK_ImplicitInstantiation);
6698 case TSK_ExplicitInstantiationDeclaration:
6700 case TSK_ExplicitInstantiationDeclaration:
6701 // This explicit instantiation declaration is redundant (that's okay).
6705 case TSK_Undeclared:
6706 case TSK_ImplicitInstantiation:
6707 // We're explicitly instantiating something that may have already been
6708 // implicitly instantiated; that's fine.
6711 case TSK_ExplicitSpecialization:
6712 // C++0x [temp.explicit]p4:
6713 // For a given set of template parameters, if an explicit instantiation
6714 // of a template appears after a declaration of an explicit
6715 // specialization for that template, the explicit instantiation has no
6720 case TSK_ExplicitInstantiationDefinition:
6721 // C++0x [temp.explicit]p10:
6722 // If an entity is the subject of both an explicit instantiation
6723 // declaration and an explicit instantiation definition in the same
6724 // translation unit, the definition shall follow the declaration.
6726 diag::err_explicit_instantiation_declaration_after_definition);
6728 // Explicit instantiations following a specialization have no effect and
6729 // hence no PrevPointOfInstantiation. In that case, walk decl backwards
6730 // until a valid name loc is found.
6731 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
6732 diag::note_explicit_instantiation_definition_here);
6737 case TSK_ExplicitInstantiationDefinition:
6739 case TSK_Undeclared:
6740 case TSK_ImplicitInstantiation:
6741 // We're explicitly instantiating something that may have already been
6742 // implicitly instantiated; that's fine.
6745 case TSK_ExplicitSpecialization:
6746 // C++ DR 259, C++0x [temp.explicit]p4:
6747 // For a given set of template parameters, if an explicit
6748 // instantiation of a template appears after a declaration of
6749 // an explicit specialization for that template, the explicit
6750 // instantiation has no effect.
6752 // In C++98/03 mode, we only give an extension warning here, because it
6753 // is not harmful to try to explicitly instantiate something that
6754 // has been explicitly specialized.
6755 Diag(NewLoc, getLangOpts().CPlusPlus11 ?
6756 diag::warn_cxx98_compat_explicit_instantiation_after_specialization :
6757 diag::ext_explicit_instantiation_after_specialization)
6759 Diag(PrevDecl->getLocation(),
6760 diag::note_previous_template_specialization);
6764 case TSK_ExplicitInstantiationDeclaration:
6765 // We're explicity instantiating a definition for something for which we
6766 // were previously asked to suppress instantiations. That's fine.
6768 // C++0x [temp.explicit]p4:
6769 // For a given set of template parameters, if an explicit instantiation
6770 // of a template appears after a declaration of an explicit
6771 // specialization for that template, the explicit instantiation has no
6773 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
6774 // Is there any previous explicit specialization declaration?
6775 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
6783 case TSK_ExplicitInstantiationDefinition:
6784 // C++0x [temp.spec]p5:
6785 // For a given template and a given set of template-arguments,
6786 // - an explicit instantiation definition shall appear at most once
6789 // MSVCCompat: MSVC silently ignores duplicate explicit instantiations.
6790 Diag(NewLoc, (getLangOpts().MSVCCompat)
6791 ? diag::ext_explicit_instantiation_duplicate
6792 : diag::err_explicit_instantiation_duplicate)
6794 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
6795 diag::note_previous_explicit_instantiation);
6801 llvm_unreachable("Missing specialization/instantiation case?");
6804 /// \brief Perform semantic analysis for the given dependent function
6805 /// template specialization.
6807 /// The only possible way to get a dependent function template specialization
6808 /// is with a friend declaration, like so:
6811 /// template \<class T> void foo(T);
6812 /// template \<class T> class A {
6813 /// friend void foo<>(T);
6817 /// There really isn't any useful analysis we can do here, so we
6818 /// just store the information.
6820 Sema::CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD,
6821 const TemplateArgumentListInfo &ExplicitTemplateArgs,
6822 LookupResult &Previous) {
6823 // Remove anything from Previous that isn't a function template in
6824 // the correct context.
6825 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
6826 LookupResult::Filter F = Previous.makeFilter();
6827 while (F.hasNext()) {
6828 NamedDecl *D = F.next()->getUnderlyingDecl();
6829 if (!isa<FunctionTemplateDecl>(D) ||
6830 !FDLookupContext->InEnclosingNamespaceSetOf(
6831 D->getDeclContext()->getRedeclContext()))
6836 // Should this be diagnosed here?
6837 if (Previous.empty()) return true;
6839 FD->setDependentTemplateSpecialization(Context, Previous.asUnresolvedSet(),
6840 ExplicitTemplateArgs);
6844 /// \brief Perform semantic analysis for the given function template
6847 /// This routine performs all of the semantic analysis required for an
6848 /// explicit function template specialization. On successful completion,
6849 /// the function declaration \p FD will become a function template
6852 /// \param FD the function declaration, which will be updated to become a
6853 /// function template specialization.
6855 /// \param ExplicitTemplateArgs the explicitly-provided template arguments,
6856 /// if any. Note that this may be valid info even when 0 arguments are
6857 /// explicitly provided as in, e.g., \c void sort<>(char*, char*);
6858 /// as it anyway contains info on the angle brackets locations.
6860 /// \param Previous the set of declarations that may be specialized by
6861 /// this function specialization.
6862 bool Sema::CheckFunctionTemplateSpecialization(
6863 FunctionDecl *FD, TemplateArgumentListInfo *ExplicitTemplateArgs,
6864 LookupResult &Previous) {
6865 // The set of function template specializations that could match this
6866 // explicit function template specialization.
6867 UnresolvedSet<8> Candidates;
6868 TemplateSpecCandidateSet FailedCandidates(FD->getLocation(),
6869 /*ForTakingAddress=*/false);
6871 llvm::SmallDenseMap<FunctionDecl *, TemplateArgumentListInfo, 8>
6872 ConvertedTemplateArgs;
6874 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
6875 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
6877 NamedDecl *Ovl = (*I)->getUnderlyingDecl();
6878 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Ovl)) {
6879 // Only consider templates found within the same semantic lookup scope as
6881 if (!FDLookupContext->InEnclosingNamespaceSetOf(
6882 Ovl->getDeclContext()->getRedeclContext()))
6885 // When matching a constexpr member function template specialization
6886 // against the primary template, we don't yet know whether the
6887 // specialization has an implicit 'const' (because we don't know whether
6888 // it will be a static member function until we know which template it
6889 // specializes), so adjust it now assuming it specializes this template.
6890 QualType FT = FD->getType();
6891 if (FD->isConstexpr()) {
6892 CXXMethodDecl *OldMD =
6893 dyn_cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl());
6894 if (OldMD && OldMD->isConst()) {
6895 const FunctionProtoType *FPT = FT->castAs<FunctionProtoType>();
6896 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
6897 EPI.TypeQuals |= Qualifiers::Const;
6898 FT = Context.getFunctionType(FPT->getReturnType(),
6899 FPT->getParamTypes(), EPI);
6903 TemplateArgumentListInfo Args;
6904 if (ExplicitTemplateArgs)
6905 Args = *ExplicitTemplateArgs;
6907 // C++ [temp.expl.spec]p11:
6908 // A trailing template-argument can be left unspecified in the
6909 // template-id naming an explicit function template specialization
6910 // provided it can be deduced from the function argument type.
6911 // Perform template argument deduction to determine whether we may be
6912 // specializing this template.
6913 // FIXME: It is somewhat wasteful to build
6914 TemplateDeductionInfo Info(FailedCandidates.getLocation());
6915 FunctionDecl *Specialization = nullptr;
6916 if (TemplateDeductionResult TDK = DeduceTemplateArguments(
6917 cast<FunctionTemplateDecl>(FunTmpl->getFirstDecl()),
6918 ExplicitTemplateArgs ? &Args : nullptr, FT, Specialization,
6920 // Template argument deduction failed; record why it failed, so
6921 // that we can provide nifty diagnostics.
6922 FailedCandidates.addCandidate().set(
6923 I.getPair(), FunTmpl->getTemplatedDecl(),
6924 MakeDeductionFailureInfo(Context, TDK, Info));
6929 // Record this candidate.
6930 if (ExplicitTemplateArgs)
6931 ConvertedTemplateArgs[Specialization] = std::move(Args);
6932 Candidates.addDecl(Specialization, I.getAccess());
6936 // Find the most specialized function template.
6937 UnresolvedSetIterator Result = getMostSpecialized(
6938 Candidates.begin(), Candidates.end(), FailedCandidates,
6940 PDiag(diag::err_function_template_spec_no_match) << FD->getDeclName(),
6941 PDiag(diag::err_function_template_spec_ambiguous)
6942 << FD->getDeclName() << (ExplicitTemplateArgs != nullptr),
6943 PDiag(diag::note_function_template_spec_matched));
6945 if (Result == Candidates.end())
6948 // Ignore access information; it doesn't figure into redeclaration checking.
6949 FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
6951 // C++ Concepts TS [dcl.spec.concept]p7: A program shall not declare [...]
6952 // an explicit specialization (14.8.3) [...] of a concept definition.
6953 if (Specialization->getPrimaryTemplate()->isConcept()) {
6954 Diag(FD->getLocation(), diag::err_concept_specialized)
6955 << 0 /*function*/ << 1 /*explicitly specialized*/;
6956 Diag(Specialization->getLocation(), diag::note_previous_declaration);
6960 FunctionTemplateSpecializationInfo *SpecInfo
6961 = Specialization->getTemplateSpecializationInfo();
6962 assert(SpecInfo && "Function template specialization info missing?");
6964 // Note: do not overwrite location info if previous template
6965 // specialization kind was explicit.
6966 TemplateSpecializationKind TSK = SpecInfo->getTemplateSpecializationKind();
6967 if (TSK == TSK_Undeclared || TSK == TSK_ImplicitInstantiation) {
6968 Specialization->setLocation(FD->getLocation());
6969 // C++11 [dcl.constexpr]p1: An explicit specialization of a constexpr
6970 // function can differ from the template declaration with respect to
6971 // the constexpr specifier.
6972 Specialization->setConstexpr(FD->isConstexpr());
6975 // FIXME: Check if the prior specialization has a point of instantiation.
6976 // If so, we have run afoul of .
6978 // If this is a friend declaration, then we're not really declaring
6979 // an explicit specialization.
6980 bool isFriend = (FD->getFriendObjectKind() != Decl::FOK_None);
6982 // Check the scope of this explicit specialization.
6984 CheckTemplateSpecializationScope(*this,
6985 Specialization->getPrimaryTemplate(),
6986 Specialization, FD->getLocation(),
6990 // C++ [temp.expl.spec]p6:
6991 // If a template, a member template or the member of a class template is
6992 // explicitly specialized then that specialization shall be declared
6993 // before the first use of that specialization that would cause an implicit
6994 // instantiation to take place, in every translation unit in which such a
6995 // use occurs; no diagnostic is required.
6996 bool HasNoEffect = false;
6998 CheckSpecializationInstantiationRedecl(FD->getLocation(),
6999 TSK_ExplicitSpecialization,
7001 SpecInfo->getTemplateSpecializationKind(),
7002 SpecInfo->getPointOfInstantiation(),
7006 // Mark the prior declaration as an explicit specialization, so that later
7007 // clients know that this is an explicit specialization.
7009 // Since explicit specializations do not inherit '=delete' from their
7010 // primary function template - check if the 'specialization' that was
7011 // implicitly generated (during template argument deduction for partial
7012 // ordering) from the most specialized of all the function templates that
7013 // 'FD' could have been specializing, has a 'deleted' definition. If so,
7014 // first check that it was implicitly generated during template argument
7015 // deduction by making sure it wasn't referenced, and then reset the deleted
7016 // flag to not-deleted, so that we can inherit that information from 'FD'.
7017 if (Specialization->isDeleted() && !SpecInfo->isExplicitSpecialization() &&
7018 !Specialization->getCanonicalDecl()->isReferenced()) {
7020 Specialization->getCanonicalDecl() == Specialization &&
7021 "This must be the only existing declaration of this specialization");
7022 Specialization->setDeletedAsWritten(false);
7024 SpecInfo->setTemplateSpecializationKind(TSK_ExplicitSpecialization);
7025 MarkUnusedFileScopedDecl(Specialization);
7028 // Turn the given function declaration into a function template
7029 // specialization, with the template arguments from the previous
7031 // Take copies of (semantic and syntactic) template argument lists.
7032 const TemplateArgumentList* TemplArgs = new (Context)
7033 TemplateArgumentList(Specialization->getTemplateSpecializationArgs());
7034 FD->setFunctionTemplateSpecialization(
7035 Specialization->getPrimaryTemplate(), TemplArgs, /*InsertPos=*/nullptr,
7036 SpecInfo->getTemplateSpecializationKind(),
7037 ExplicitTemplateArgs ? &ConvertedTemplateArgs[Specialization] : nullptr);
7039 // The "previous declaration" for this function template specialization is
7040 // the prior function template specialization.
7042 Previous.addDecl(Specialization);
7046 /// \brief Perform semantic analysis for the given non-template member
7049 /// This routine performs all of the semantic analysis required for an
7050 /// explicit member function specialization. On successful completion,
7051 /// the function declaration \p FD will become a member function
7054 /// \param Member the member declaration, which will be updated to become a
7057 /// \param Previous the set of declarations, one of which may be specialized
7058 /// by this function specialization; the set will be modified to contain the
7059 /// redeclared member.
7061 Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
7062 assert(!isa<TemplateDecl>(Member) && "Only for non-template members");
7064 // Try to find the member we are instantiating.
7065 NamedDecl *FoundInstantiation = nullptr;
7066 NamedDecl *Instantiation = nullptr;
7067 NamedDecl *InstantiatedFrom = nullptr;
7068 MemberSpecializationInfo *MSInfo = nullptr;
7070 if (Previous.empty()) {
7071 // Nowhere to look anyway.
7072 } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Member)) {
7073 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
7075 NamedDecl *D = (*I)->getUnderlyingDecl();
7076 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
7077 QualType Adjusted = Function->getType();
7078 if (!hasExplicitCallingConv(Adjusted))
7079 Adjusted = adjustCCAndNoReturn(Adjusted, Method->getType());
7080 if (Context.hasSameType(Adjusted, Method->getType())) {
7081 FoundInstantiation = *I;
7082 Instantiation = Method;
7083 InstantiatedFrom = Method->getInstantiatedFromMemberFunction();
7084 MSInfo = Method->getMemberSpecializationInfo();
7089 } else if (isa<VarDecl>(Member)) {
7091 if (Previous.isSingleResult() &&
7092 (PrevVar = dyn_cast<VarDecl>(Previous.getFoundDecl())))
7093 if (PrevVar->isStaticDataMember()) {
7094 FoundInstantiation = Previous.getRepresentativeDecl();
7095 Instantiation = PrevVar;
7096 InstantiatedFrom = PrevVar->getInstantiatedFromStaticDataMember();
7097 MSInfo = PrevVar->getMemberSpecializationInfo();
7099 } else if (isa<RecordDecl>(Member)) {
7100 CXXRecordDecl *PrevRecord;
7101 if (Previous.isSingleResult() &&
7102 (PrevRecord = dyn_cast<CXXRecordDecl>(Previous.getFoundDecl()))) {
7103 FoundInstantiation = Previous.getRepresentativeDecl();
7104 Instantiation = PrevRecord;
7105 InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass();
7106 MSInfo = PrevRecord->getMemberSpecializationInfo();
7108 } else if (isa<EnumDecl>(Member)) {
7110 if (Previous.isSingleResult() &&
7111 (PrevEnum = dyn_cast<EnumDecl>(Previous.getFoundDecl()))) {
7112 FoundInstantiation = Previous.getRepresentativeDecl();
7113 Instantiation = PrevEnum;
7114 InstantiatedFrom = PrevEnum->getInstantiatedFromMemberEnum();
7115 MSInfo = PrevEnum->getMemberSpecializationInfo();
7119 if (!Instantiation) {
7120 // There is no previous declaration that matches. Since member
7121 // specializations are always out-of-line, the caller will complain about
7122 // this mismatch later.
7126 // If this is a friend, just bail out here before we start turning
7127 // things into explicit specializations.
7128 if (Member->getFriendObjectKind() != Decl::FOK_None) {
7129 // Preserve instantiation information.
7130 if (InstantiatedFrom && isa<CXXMethodDecl>(Member)) {
7131 cast<CXXMethodDecl>(Member)->setInstantiationOfMemberFunction(
7132 cast<CXXMethodDecl>(InstantiatedFrom),
7133 cast<CXXMethodDecl>(Instantiation)->getTemplateSpecializationKind());
7134 } else if (InstantiatedFrom && isa<CXXRecordDecl>(Member)) {
7135 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
7136 cast<CXXRecordDecl>(InstantiatedFrom),
7137 cast<CXXRecordDecl>(Instantiation)->getTemplateSpecializationKind());
7141 Previous.addDecl(FoundInstantiation);
7145 // Make sure that this is a specialization of a member.
7146 if (!InstantiatedFrom) {
7147 Diag(Member->getLocation(), diag::err_spec_member_not_instantiated)
7149 Diag(Instantiation->getLocation(), diag::note_specialized_decl);
7153 // C++ [temp.expl.spec]p6:
7154 // If a template, a member template or the member of a class template is
7155 // explicitly specialized then that specialization shall be declared
7156 // before the first use of that specialization that would cause an implicit
7157 // instantiation to take place, in every translation unit in which such a
7158 // use occurs; no diagnostic is required.
7159 assert(MSInfo && "Member specialization info missing?");
7161 bool HasNoEffect = false;
7162 if (CheckSpecializationInstantiationRedecl(Member->getLocation(),
7163 TSK_ExplicitSpecialization,
7165 MSInfo->getTemplateSpecializationKind(),
7166 MSInfo->getPointOfInstantiation(),
7170 // Check the scope of this explicit specialization.
7171 if (CheckTemplateSpecializationScope(*this,
7173 Instantiation, Member->getLocation(),
7177 // Note that this is an explicit instantiation of a member.
7178 // the original declaration to note that it is an explicit specialization
7179 // (if it was previously an implicit instantiation). This latter step
7180 // makes bookkeeping easier.
7181 if (isa<FunctionDecl>(Member)) {
7182 FunctionDecl *InstantiationFunction = cast<FunctionDecl>(Instantiation);
7183 if (InstantiationFunction->getTemplateSpecializationKind() ==
7184 TSK_ImplicitInstantiation) {
7185 InstantiationFunction->setTemplateSpecializationKind(
7186 TSK_ExplicitSpecialization);
7187 InstantiationFunction->setLocation(Member->getLocation());
7188 // Explicit specializations of member functions of class templates do not
7189 // inherit '=delete' from the member function they are specializing.
7190 if (InstantiationFunction->isDeleted()) {
7191 assert(InstantiationFunction->getCanonicalDecl() ==
7192 InstantiationFunction);
7193 InstantiationFunction->setDeletedAsWritten(false);
\r
7197 cast<FunctionDecl>(Member)->setInstantiationOfMemberFunction(
7198 cast<CXXMethodDecl>(InstantiatedFrom),
7199 TSK_ExplicitSpecialization);
7200 MarkUnusedFileScopedDecl(InstantiationFunction);
7201 } else if (isa<VarDecl>(Member)) {
7202 VarDecl *InstantiationVar = cast<VarDecl>(Instantiation);
7203 if (InstantiationVar->getTemplateSpecializationKind() ==
7204 TSK_ImplicitInstantiation) {
7205 InstantiationVar->setTemplateSpecializationKind(
7206 TSK_ExplicitSpecialization);
7207 InstantiationVar->setLocation(Member->getLocation());
7210 cast<VarDecl>(Member)->setInstantiationOfStaticDataMember(
7211 cast<VarDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
7212 MarkUnusedFileScopedDecl(InstantiationVar);
7213 } else if (isa<CXXRecordDecl>(Member)) {
7214 CXXRecordDecl *InstantiationClass = cast<CXXRecordDecl>(Instantiation);
7215 if (InstantiationClass->getTemplateSpecializationKind() ==
7216 TSK_ImplicitInstantiation) {
7217 InstantiationClass->setTemplateSpecializationKind(
7218 TSK_ExplicitSpecialization);
7219 InstantiationClass->setLocation(Member->getLocation());
7222 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
7223 cast<CXXRecordDecl>(InstantiatedFrom),
7224 TSK_ExplicitSpecialization);
7226 assert(isa<EnumDecl>(Member) && "Only member enums remain");
7227 EnumDecl *InstantiationEnum = cast<EnumDecl>(Instantiation);
7228 if (InstantiationEnum->getTemplateSpecializationKind() ==
7229 TSK_ImplicitInstantiation) {
7230 InstantiationEnum->setTemplateSpecializationKind(
7231 TSK_ExplicitSpecialization);
7232 InstantiationEnum->setLocation(Member->getLocation());
7235 cast<EnumDecl>(Member)->setInstantiationOfMemberEnum(
7236 cast<EnumDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
7239 // Save the caller the trouble of having to figure out which declaration
7240 // this specialization matches.
7242 Previous.addDecl(FoundInstantiation);
7246 /// \brief Check the scope of an explicit instantiation.
7248 /// \returns true if a serious error occurs, false otherwise.
7249 static bool CheckExplicitInstantiationScope(Sema &S, NamedDecl *D,
7250 SourceLocation InstLoc,
7251 bool WasQualifiedName) {
7252 DeclContext *OrigContext= D->getDeclContext()->getEnclosingNamespaceContext();
7253 DeclContext *CurContext = S.CurContext->getRedeclContext();
7255 if (CurContext->isRecord()) {
7256 S.Diag(InstLoc, diag::err_explicit_instantiation_in_class)
7261 // C++11 [temp.explicit]p3:
7262 // An explicit instantiation shall appear in an enclosing namespace of its
7263 // template. If the name declared in the explicit instantiation is an
7264 // unqualified name, the explicit instantiation shall appear in the
7265 // namespace where its template is declared or, if that namespace is inline
7266 // (7.3.1), any namespace from its enclosing namespace set.
7268 // This is DR275, which we do not retroactively apply to C++98/03.
7269 if (WasQualifiedName) {
7270 if (CurContext->Encloses(OrigContext))
7273 if (CurContext->InEnclosingNamespaceSetOf(OrigContext))
7277 if (NamespaceDecl *NS = dyn_cast<NamespaceDecl>(OrigContext)) {
7278 if (WasQualifiedName)
7280 S.getLangOpts().CPlusPlus11?
7281 diag::err_explicit_instantiation_out_of_scope :
7282 diag::warn_explicit_instantiation_out_of_scope_0x)
7286 S.getLangOpts().CPlusPlus11?
7287 diag::err_explicit_instantiation_unqualified_wrong_namespace :
7288 diag::warn_explicit_instantiation_unqualified_wrong_namespace_0x)
7292 S.getLangOpts().CPlusPlus11?
7293 diag::err_explicit_instantiation_must_be_global :
7294 diag::warn_explicit_instantiation_must_be_global_0x)
7296 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here);
7300 /// \brief Determine whether the given scope specifier has a template-id in it.
7301 static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec &SS) {
7305 // C++11 [temp.explicit]p3:
7306 // If the explicit instantiation is for a member function, a member class
7307 // or a static data member of a class template specialization, the name of
7308 // the class template specialization in the qualified-id for the member
7309 // name shall be a simple-template-id.
7311 // C++98 has the same restriction, just worded differently.
7312 for (NestedNameSpecifier *NNS = SS.getScopeRep(); NNS;
7313 NNS = NNS->getPrefix())
7314 if (const Type *T = NNS->getAsType())
7315 if (isa<TemplateSpecializationType>(T))
7321 // Explicit instantiation of a class template specialization
7323 Sema::ActOnExplicitInstantiation(Scope *S,
7324 SourceLocation ExternLoc,
7325 SourceLocation TemplateLoc,
7327 SourceLocation KWLoc,
7328 const CXXScopeSpec &SS,
7329 TemplateTy TemplateD,
7330 SourceLocation TemplateNameLoc,
7331 SourceLocation LAngleLoc,
7332 ASTTemplateArgsPtr TemplateArgsIn,
7333 SourceLocation RAngleLoc,
7334 AttributeList *Attr) {
7335 // Find the class template we're specializing
7336 TemplateName Name = TemplateD.get();
7337 TemplateDecl *TD = Name.getAsTemplateDecl();
7338 // Check that the specialization uses the same tag kind as the
7339 // original template.
7340 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
7341 assert(Kind != TTK_Enum &&
7342 "Invalid enum tag in class template explicit instantiation!");
7344 ClassTemplateDecl *ClassTemplate = dyn_cast<ClassTemplateDecl>(TD);
7346 if (!ClassTemplate) {
7347 unsigned ErrorKind = 0;
7348 if (isa<TypeAliasTemplateDecl>(TD)) {
7350 } else if (isa<TemplateTemplateParmDecl>(TD)) {
7354 Diag(TemplateNameLoc, diag::err_tag_reference_non_tag) << ErrorKind;
7355 Diag(TD->getLocation(), diag::note_previous_use);
7359 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
7360 Kind, /*isDefinition*/false, KWLoc,
7361 ClassTemplate->getIdentifier())) {
7362 Diag(KWLoc, diag::err_use_with_wrong_tag)
7364 << FixItHint::CreateReplacement(KWLoc,
7365 ClassTemplate->getTemplatedDecl()->getKindName());
7366 Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
7367 diag::note_previous_use);
7368 Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
7371 // C++0x [temp.explicit]p2:
7372 // There are two forms of explicit instantiation: an explicit instantiation
7373 // definition and an explicit instantiation declaration. An explicit
7374 // instantiation declaration begins with the extern keyword. [...]
7375 TemplateSpecializationKind TSK = ExternLoc.isInvalid()
7376 ? TSK_ExplicitInstantiationDefinition
7377 : TSK_ExplicitInstantiationDeclaration;
7379 if (TSK == TSK_ExplicitInstantiationDeclaration) {
7380 // Check for dllexport class template instantiation declarations.
7381 for (AttributeList *A = Attr; A; A = A->getNext()) {
7382 if (A->getKind() == AttributeList::AT_DLLExport) {
7384 diag::warn_attribute_dllexport_explicit_instantiation_decl);
7385 Diag(A->getLoc(), diag::note_attribute);
7390 if (auto *A = ClassTemplate->getTemplatedDecl()->getAttr<DLLExportAttr>()) {
7392 diag::warn_attribute_dllexport_explicit_instantiation_decl);
7393 Diag(A->getLocation(), diag::note_attribute);
7397 // In MSVC mode, dllimported explicit instantiation definitions are treated as
7398 // instantiation declarations for most purposes.
7399 bool DLLImportExplicitInstantiationDef = false;
7400 if (TSK == TSK_ExplicitInstantiationDefinition &&
7401 Context.getTargetInfo().getCXXABI().isMicrosoft()) {
7402 // Check for dllimport class template instantiation definitions.
7404 ClassTemplate->getTemplatedDecl()->getAttr<DLLImportAttr>();
7405 for (AttributeList *A = Attr; A; A = A->getNext()) {
7406 if (A->getKind() == AttributeList::AT_DLLImport)
7408 if (A->getKind() == AttributeList::AT_DLLExport) {
7409 // dllexport trumps dllimport here.
7415 TSK = TSK_ExplicitInstantiationDeclaration;
7416 DLLImportExplicitInstantiationDef = true;
7420 // Translate the parser's template argument list in our AST format.
7421 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
7422 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
7424 // Check that the template argument list is well-formed for this
7426 SmallVector<TemplateArgument, 4> Converted;
7427 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
7428 TemplateArgs, false, Converted))
7431 // Find the class template specialization declaration that
7432 // corresponds to these arguments.
7433 void *InsertPos = nullptr;
7434 ClassTemplateSpecializationDecl *PrevDecl
7435 = ClassTemplate->findSpecialization(Converted, InsertPos);
7437 TemplateSpecializationKind PrevDecl_TSK
7438 = PrevDecl ? PrevDecl->getTemplateSpecializationKind() : TSK_Undeclared;
7440 // C++0x [temp.explicit]p2:
7441 // [...] An explicit instantiation shall appear in an enclosing
7442 // namespace of its template. [...]
7444 // This is C++ DR 275.
7445 if (CheckExplicitInstantiationScope(*this, ClassTemplate, TemplateNameLoc,
7449 ClassTemplateSpecializationDecl *Specialization = nullptr;
7451 bool HasNoEffect = false;
7453 if (CheckSpecializationInstantiationRedecl(TemplateNameLoc, TSK,
7454 PrevDecl, PrevDecl_TSK,
7455 PrevDecl->getPointOfInstantiation(),
7459 // Even though HasNoEffect == true means that this explicit instantiation
7460 // has no effect on semantics, we go on to put its syntax in the AST.
7462 if (PrevDecl_TSK == TSK_ImplicitInstantiation ||
7463 PrevDecl_TSK == TSK_Undeclared) {
7464 // Since the only prior class template specialization with these
7465 // arguments was referenced but not declared, reuse that
7466 // declaration node as our own, updating the source location
7467 // for the template name to reflect our new declaration.
7468 // (Other source locations will be updated later.)
7469 Specialization = PrevDecl;
7470 Specialization->setLocation(TemplateNameLoc);
7474 if (PrevDecl_TSK == TSK_ExplicitInstantiationDeclaration &&
7475 DLLImportExplicitInstantiationDef) {
7476 // The new specialization might add a dllimport attribute.
7477 HasNoEffect = false;
7481 if (!Specialization) {
7482 // Create a new class template specialization declaration node for
7483 // this explicit specialization.
7485 = ClassTemplateSpecializationDecl::Create(Context, Kind,
7486 ClassTemplate->getDeclContext(),
7487 KWLoc, TemplateNameLoc,
7491 SetNestedNameSpecifier(Specialization, SS);
7493 if (!HasNoEffect && !PrevDecl) {
7494 // Insert the new specialization.
7495 ClassTemplate->AddSpecialization(Specialization, InsertPos);
7499 // Build the fully-sugared type for this explicit instantiation as
7500 // the user wrote in the explicit instantiation itself. This means
7501 // that we'll pretty-print the type retrieved from the
7502 // specialization's declaration the way that the user actually wrote
7503 // the explicit instantiation, rather than formatting the name based
7504 // on the "canonical" representation used to store the template
7505 // arguments in the specialization.
7506 TypeSourceInfo *WrittenTy
7507 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
7509 Context.getTypeDeclType(Specialization));
7510 Specialization->setTypeAsWritten(WrittenTy);
7512 // Set source locations for keywords.
7513 Specialization->setExternLoc(ExternLoc);
7514 Specialization->setTemplateKeywordLoc(TemplateLoc);
7515 Specialization->setRBraceLoc(SourceLocation());
7518 ProcessDeclAttributeList(S, Specialization, Attr);
7520 // Add the explicit instantiation into its lexical context. However,
7521 // since explicit instantiations are never found by name lookup, we
7522 // just put it into the declaration context directly.
7523 Specialization->setLexicalDeclContext(CurContext);
7524 CurContext->addDecl(Specialization);
7526 // Syntax is now OK, so return if it has no other effect on semantics.
7528 // Set the template specialization kind.
7529 Specialization->setTemplateSpecializationKind(TSK);
7530 return Specialization;
7533 // C++ [temp.explicit]p3:
7534 // A definition of a class template or class member template
7535 // shall be in scope at the point of the explicit instantiation of
7536 // the class template or class member template.
7538 // This check comes when we actually try to perform the
7540 ClassTemplateSpecializationDecl *Def
7541 = cast_or_null<ClassTemplateSpecializationDecl>(
7542 Specialization->getDefinition());
7544 InstantiateClassTemplateSpecialization(TemplateNameLoc, Specialization, TSK);
7545 else if (TSK == TSK_ExplicitInstantiationDefinition) {
7546 MarkVTableUsed(TemplateNameLoc, Specialization, true);
7547 Specialization->setPointOfInstantiation(Def->getPointOfInstantiation());
7550 // Instantiate the members of this class template specialization.
7551 Def = cast_or_null<ClassTemplateSpecializationDecl>(
7552 Specialization->getDefinition());
7554 TemplateSpecializationKind Old_TSK = Def->getTemplateSpecializationKind();
7555 // Fix a TSK_ExplicitInstantiationDeclaration followed by a
7556 // TSK_ExplicitInstantiationDefinition
7557 if (Old_TSK == TSK_ExplicitInstantiationDeclaration &&
7558 (TSK == TSK_ExplicitInstantiationDefinition ||
7559 DLLImportExplicitInstantiationDef)) {
7560 // FIXME: Need to notify the ASTMutationListener that we did this.
7561 Def->setTemplateSpecializationKind(TSK);
7563 if (!getDLLAttr(Def) && getDLLAttr(Specialization) &&
7564 Context.getTargetInfo().getCXXABI().isMicrosoft()) {
7565 // In the MS ABI, an explicit instantiation definition can add a dll
7566 // attribute to a template with a previous instantiation declaration.
7567 // MinGW doesn't allow this.
7568 auto *A = cast<InheritableAttr>(
7569 getDLLAttr(Specialization)->clone(getASTContext()));
7570 A->setInherited(true);
7573 // We reject explicit instantiations in class scope, so there should
7574 // never be any delayed exported classes to worry about.
7575 assert(DelayedDllExportClasses.empty() &&
7576 "delayed exports present at explicit instantiation");
7577 checkClassLevelDLLAttribute(Def);
7578 referenceDLLExportedClassMethods();
7580 // Propagate attribute to base class templates.
7581 for (auto &B : Def->bases()) {
7582 if (auto *BT = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
7583 B.getType()->getAsCXXRecordDecl()))
7584 propagateDLLAttrToBaseClassTemplate(Def, A, BT, B.getLocStart());
7589 // Set the template specialization kind. Make sure it is set before
7590 // instantiating the members which will trigger ASTConsumer callbacks.
7591 Specialization->setTemplateSpecializationKind(TSK);
7592 InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK);
7595 // Set the template specialization kind.
7596 Specialization->setTemplateSpecializationKind(TSK);
7599 return Specialization;
7602 // Explicit instantiation of a member class of a class template.
7604 Sema::ActOnExplicitInstantiation(Scope *S,
7605 SourceLocation ExternLoc,
7606 SourceLocation TemplateLoc,
7608 SourceLocation KWLoc,
7610 IdentifierInfo *Name,
7611 SourceLocation NameLoc,
7612 AttributeList *Attr) {
7615 bool IsDependent = false;
7616 Decl *TagD = ActOnTag(S, TagSpec, Sema::TUK_Reference,
7617 KWLoc, SS, Name, NameLoc, Attr, AS_none,
7618 /*ModulePrivateLoc=*/SourceLocation(),
7619 MultiTemplateParamsArg(), Owned, IsDependent,
7620 SourceLocation(), false, TypeResult(),
7621 /*IsTypeSpecifier*/false);
7622 assert(!IsDependent && "explicit instantiation of dependent name not yet handled");
7627 TagDecl *Tag = cast<TagDecl>(TagD);
7628 assert(!Tag->isEnum() && "shouldn't see enumerations here");
7630 if (Tag->isInvalidDecl())
7633 CXXRecordDecl *Record = cast<CXXRecordDecl>(Tag);
7634 CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass();
7636 Diag(TemplateLoc, diag::err_explicit_instantiation_nontemplate_type)
7637 << Context.getTypeDeclType(Record);
7638 Diag(Record->getLocation(), diag::note_nontemplate_decl_here);
7642 // C++0x [temp.explicit]p2:
7643 // If the explicit instantiation is for a class or member class, the
7644 // elaborated-type-specifier in the declaration shall include a
7645 // simple-template-id.
7647 // C++98 has the same restriction, just worded differently.
7648 if (!ScopeSpecifierHasTemplateId(SS))
7649 Diag(TemplateLoc, diag::ext_explicit_instantiation_without_qualified_id)
7650 << Record << SS.getRange();
7652 // C++0x [temp.explicit]p2:
7653 // There are two forms of explicit instantiation: an explicit instantiation
7654 // definition and an explicit instantiation declaration. An explicit
7655 // instantiation declaration begins with the extern keyword. [...]
7656 TemplateSpecializationKind TSK
7657 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
7658 : TSK_ExplicitInstantiationDeclaration;
7660 // C++0x [temp.explicit]p2:
7661 // [...] An explicit instantiation shall appear in an enclosing
7662 // namespace of its template. [...]
7664 // This is C++ DR 275.
7665 CheckExplicitInstantiationScope(*this, Record, NameLoc, true);
7667 // Verify that it is okay to explicitly instantiate here.
7668 CXXRecordDecl *PrevDecl
7669 = cast_or_null<CXXRecordDecl>(Record->getPreviousDecl());
7670 if (!PrevDecl && Record->getDefinition())
7673 MemberSpecializationInfo *MSInfo = PrevDecl->getMemberSpecializationInfo();
7674 bool HasNoEffect = false;
7675 assert(MSInfo && "No member specialization information?");
7676 if (CheckSpecializationInstantiationRedecl(TemplateLoc, TSK,
7678 MSInfo->getTemplateSpecializationKind(),
7679 MSInfo->getPointOfInstantiation(),
7686 CXXRecordDecl *RecordDef
7687 = cast_or_null<CXXRecordDecl>(Record->getDefinition());
7689 // C++ [temp.explicit]p3:
7690 // A definition of a member class of a class template shall be in scope
7691 // at the point of an explicit instantiation of the member class.
7693 = cast_or_null<CXXRecordDecl>(Pattern->getDefinition());
7695 Diag(TemplateLoc, diag::err_explicit_instantiation_undefined_member)
7696 << 0 << Record->getDeclName() << Record->getDeclContext();
7697 Diag(Pattern->getLocation(), diag::note_forward_declaration)
7701 if (InstantiateClass(NameLoc, Record, Def,
7702 getTemplateInstantiationArgs(Record),
7706 RecordDef = cast_or_null<CXXRecordDecl>(Record->getDefinition());
7712 // Instantiate all of the members of the class.
7713 InstantiateClassMembers(NameLoc, RecordDef,
7714 getTemplateInstantiationArgs(Record), TSK);
7716 if (TSK == TSK_ExplicitInstantiationDefinition)
7717 MarkVTableUsed(NameLoc, RecordDef, true);
7719 // FIXME: We don't have any representation for explicit instantiations of
7720 // member classes. Such a representation is not needed for compilation, but it
7721 // should be available for clients that want to see all of the declarations in
7726 DeclResult Sema::ActOnExplicitInstantiation(Scope *S,
7727 SourceLocation ExternLoc,
7728 SourceLocation TemplateLoc,
7730 // Explicit instantiations always require a name.
7731 // TODO: check if/when DNInfo should replace Name.
7732 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
7733 DeclarationName Name = NameInfo.getName();
7735 if (!D.isInvalidType())
7736 Diag(D.getDeclSpec().getLocStart(),
7737 diag::err_explicit_instantiation_requires_name)
7738 << D.getDeclSpec().getSourceRange()
7739 << D.getSourceRange();
7744 // The scope passed in may not be a decl scope. Zip up the scope tree until
7745 // we find one that is.
7746 while ((S->getFlags() & Scope::DeclScope) == 0 ||
7747 (S->getFlags() & Scope::TemplateParamScope) != 0)
7750 // Determine the type of the declaration.
7751 TypeSourceInfo *T = GetTypeForDeclarator(D, S);
7752 QualType R = T->getType();
7757 // A storage-class-specifier shall not be specified in [...] an explicit
7758 // instantiation (14.7.2) directive.
7759 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
7760 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_of_typedef)
7763 } else if (D.getDeclSpec().getStorageClassSpec()
7764 != DeclSpec::SCS_unspecified) {
7765 // Complain about then remove the storage class specifier.
7766 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_storage_class)
7767 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
7769 D.getMutableDeclSpec().ClearStorageClassSpecs();
7772 // C++0x [temp.explicit]p1:
7773 // [...] An explicit instantiation of a function template shall not use the
7774 // inline or constexpr specifiers.
7775 // Presumably, this also applies to member functions of class templates as
7777 if (D.getDeclSpec().isInlineSpecified())
7778 Diag(D.getDeclSpec().getInlineSpecLoc(),
7779 getLangOpts().CPlusPlus11 ?
7780 diag::err_explicit_instantiation_inline :
7781 diag::warn_explicit_instantiation_inline_0x)
7782 << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
7783 if (D.getDeclSpec().isConstexprSpecified() && R->isFunctionType())
7784 // FIXME: Add a fix-it to remove the 'constexpr' and add a 'const' if one is
7785 // not already specified.
7786 Diag(D.getDeclSpec().getConstexprSpecLoc(),
7787 diag::err_explicit_instantiation_constexpr);
7789 // C++ Concepts TS [dcl.spec.concept]p1: The concept specifier shall be
7790 // applied only to the definition of a function template or variable template,
7791 // declared in namespace scope.
7792 if (D.getDeclSpec().isConceptSpecified()) {
7793 Diag(D.getDeclSpec().getConceptSpecLoc(),
7794 diag::err_concept_specified_specialization) << 0;
7798 // C++0x [temp.explicit]p2:
7799 // There are two forms of explicit instantiation: an explicit instantiation
7800 // definition and an explicit instantiation declaration. An explicit
7801 // instantiation declaration begins with the extern keyword. [...]
7802 TemplateSpecializationKind TSK
7803 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
7804 : TSK_ExplicitInstantiationDeclaration;
7806 LookupResult Previous(*this, NameInfo, LookupOrdinaryName);
7807 LookupParsedName(Previous, S, &D.getCXXScopeSpec());
7809 if (!R->isFunctionType()) {
7810 // C++ [temp.explicit]p1:
7811 // A [...] static data member of a class template can be explicitly
7812 // instantiated from the member definition associated with its class
7814 // C++1y [temp.explicit]p1:
7815 // A [...] variable [...] template specialization can be explicitly
7816 // instantiated from its template.
7817 if (Previous.isAmbiguous())
7820 VarDecl *Prev = Previous.getAsSingle<VarDecl>();
7821 VarTemplateDecl *PrevTemplate = Previous.getAsSingle<VarTemplateDecl>();
7823 if (!PrevTemplate) {
7824 if (!Prev || !Prev->isStaticDataMember()) {
7825 // We expect to see a data data member here.
7826 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_not_known)
7828 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
7830 Diag((*P)->getLocation(), diag::note_explicit_instantiation_here);
7834 if (!Prev->getInstantiatedFromStaticDataMember()) {
7835 // FIXME: Check for explicit specialization?
7836 Diag(D.getIdentifierLoc(),
7837 diag::err_explicit_instantiation_data_member_not_instantiated)
7839 Diag(Prev->getLocation(), diag::note_explicit_instantiation_here);
7840 // FIXME: Can we provide a note showing where this was declared?
7844 // Explicitly instantiate a variable template.
7846 // C++1y [dcl.spec.auto]p6:
7847 // ... A program that uses auto or decltype(auto) in a context not
7848 // explicitly allowed in this section is ill-formed.
7850 // This includes auto-typed variable template instantiations.
7851 if (R->isUndeducedType()) {
7852 Diag(T->getTypeLoc().getLocStart(),
7853 diag::err_auto_not_allowed_var_inst);
7857 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId) {
7858 // C++1y [temp.explicit]p3:
7859 // If the explicit instantiation is for a variable, the unqualified-id
7860 // in the declaration shall be a template-id.
7861 Diag(D.getIdentifierLoc(),
7862 diag::err_explicit_instantiation_without_template_id)
7864 Diag(PrevTemplate->getLocation(),
7865 diag::note_explicit_instantiation_here);
7869 // C++ Concepts TS [dcl.spec.concept]p7: A program shall not declare an
7870 // explicit instantiation (14.8.2) [...] of a concept definition.
7871 if (PrevTemplate->isConcept()) {
7872 Diag(D.getIdentifierLoc(), diag::err_concept_specialized)
7873 << 1 /*variable*/ << 0 /*explicitly instantiated*/;
7874 Diag(PrevTemplate->getLocation(), diag::note_previous_declaration);
7878 // Translate the parser's template argument list into our AST format.
7879 TemplateArgumentListInfo TemplateArgs =
7880 makeTemplateArgumentListInfo(*this, *D.getName().TemplateId);
7882 DeclResult Res = CheckVarTemplateId(PrevTemplate, TemplateLoc,
7883 D.getIdentifierLoc(), TemplateArgs);
7884 if (Res.isInvalid())
7887 // Ignore access control bits, we don't need them for redeclaration
7889 Prev = cast<VarDecl>(Res.get());
7892 // C++0x [temp.explicit]p2:
7893 // If the explicit instantiation is for a member function, a member class
7894 // or a static data member of a class template specialization, the name of
7895 // the class template specialization in the qualified-id for the member
7896 // name shall be a simple-template-id.
7898 // C++98 has the same restriction, just worded differently.
7900 // This does not apply to variable template specializations, where the
7901 // template-id is in the unqualified-id instead.
7902 if (!ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()) && !PrevTemplate)
7903 Diag(D.getIdentifierLoc(),
7904 diag::ext_explicit_instantiation_without_qualified_id)
7905 << Prev << D.getCXXScopeSpec().getRange();
7907 // Check the scope of this explicit instantiation.
7908 CheckExplicitInstantiationScope(*this, Prev, D.getIdentifierLoc(), true);
7910 // Verify that it is okay to explicitly instantiate here.
7911 TemplateSpecializationKind PrevTSK = Prev->getTemplateSpecializationKind();
7912 SourceLocation POI = Prev->getPointOfInstantiation();
7913 bool HasNoEffect = false;
7914 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, Prev,
7915 PrevTSK, POI, HasNoEffect))
7919 // Instantiate static data member or variable template.
7921 Prev->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
7923 // Merge attributes.
7924 if (AttributeList *Attr = D.getDeclSpec().getAttributes().getList())
7925 ProcessDeclAttributeList(S, Prev, Attr);
7927 if (TSK == TSK_ExplicitInstantiationDefinition)
7928 InstantiateVariableDefinition(D.getIdentifierLoc(), Prev);
7931 // Check the new variable specialization against the parsed input.
7932 if (PrevTemplate && Prev && !Context.hasSameType(Prev->getType(), R)) {
7933 Diag(T->getTypeLoc().getLocStart(),
7934 diag::err_invalid_var_template_spec_type)
7935 << 0 << PrevTemplate << R << Prev->getType();
7936 Diag(PrevTemplate->getLocation(), diag::note_template_declared_here)
7937 << 2 << PrevTemplate->getDeclName();
7941 // FIXME: Create an ExplicitInstantiation node?
7942 return (Decl*) nullptr;
7945 // If the declarator is a template-id, translate the parser's template
7946 // argument list into our AST format.
7947 bool HasExplicitTemplateArgs = false;
7948 TemplateArgumentListInfo TemplateArgs;
7949 if (D.getName().getKind() == UnqualifiedId::IK_TemplateId) {
7950 TemplateArgs = makeTemplateArgumentListInfo(*this, *D.getName().TemplateId);
7951 HasExplicitTemplateArgs = true;
7954 // C++ [temp.explicit]p1:
7955 // A [...] function [...] can be explicitly instantiated from its template.
7956 // A member function [...] of a class template can be explicitly
7957 // instantiated from the member definition associated with its class
7959 UnresolvedSet<8> Matches;
7960 TemplateSpecCandidateSet FailedCandidates(D.getIdentifierLoc());
7961 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
7963 NamedDecl *Prev = *P;
7964 if (!HasExplicitTemplateArgs) {
7965 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Prev)) {
7966 QualType Adjusted = adjustCCAndNoReturn(R, Method->getType());
7967 if (Context.hasSameUnqualifiedType(Method->getType(), Adjusted)) {
7970 Matches.addDecl(Method, P.getAccess());
7971 if (Method->getTemplateSpecializationKind() == TSK_Undeclared)
7977 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Prev);
7981 TemplateDeductionInfo Info(FailedCandidates.getLocation());
7982 FunctionDecl *Specialization = nullptr;
7983 if (TemplateDeductionResult TDK
7984 = DeduceTemplateArguments(FunTmpl,
7985 (HasExplicitTemplateArgs ? &TemplateArgs
7987 R, Specialization, Info)) {
7988 // Keep track of almost-matches.
7989 FailedCandidates.addCandidate()
7990 .set(P.getPair(), FunTmpl->getTemplatedDecl(),
7991 MakeDeductionFailureInfo(Context, TDK, Info));
7996 Matches.addDecl(Specialization, P.getAccess());
7999 // Find the most specialized function template specialization.
8000 UnresolvedSetIterator Result = getMostSpecialized(
8001 Matches.begin(), Matches.end(), FailedCandidates,
8002 D.getIdentifierLoc(),
8003 PDiag(diag::err_explicit_instantiation_not_known) << Name,
8004 PDiag(diag::err_explicit_instantiation_ambiguous) << Name,
8005 PDiag(diag::note_explicit_instantiation_candidate));
8007 if (Result == Matches.end())
8010 // Ignore access control bits, we don't need them for redeclaration checking.
8011 FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
8013 // C++11 [except.spec]p4
8014 // In an explicit instantiation an exception-specification may be specified,
8015 // but is not required.
8016 // If an exception-specification is specified in an explicit instantiation
8017 // directive, it shall be compatible with the exception-specifications of
8018 // other declarations of that function.
8019 if (auto *FPT = R->getAs<FunctionProtoType>())
8020 if (FPT->hasExceptionSpec()) {
8022 diag::err_mismatched_exception_spec_explicit_instantiation;
8023 if (getLangOpts().MicrosoftExt)
8024 DiagID = diag::ext_mismatched_exception_spec_explicit_instantiation;
8025 bool Result = CheckEquivalentExceptionSpec(
8026 PDiag(DiagID) << Specialization->getType(),
8027 PDiag(diag::note_explicit_instantiation_here),
8028 Specialization->getType()->getAs<FunctionProtoType>(),
8029 Specialization->getLocation(), FPT, D.getLocStart());
8030 // In Microsoft mode, mismatching exception specifications just cause a
8032 if (!getLangOpts().MicrosoftExt && Result)
8036 if (Specialization->getTemplateSpecializationKind() == TSK_Undeclared) {
8037 Diag(D.getIdentifierLoc(),
8038 diag::err_explicit_instantiation_member_function_not_instantiated)
8040 << (Specialization->getTemplateSpecializationKind() ==
8041 TSK_ExplicitSpecialization);
8042 Diag(Specialization->getLocation(), diag::note_explicit_instantiation_here);
8046 FunctionDecl *PrevDecl = Specialization->getPreviousDecl();
8047 if (!PrevDecl && Specialization->isThisDeclarationADefinition())
8048 PrevDecl = Specialization;
8051 bool HasNoEffect = false;
8052 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK,
8054 PrevDecl->getTemplateSpecializationKind(),
8055 PrevDecl->getPointOfInstantiation(),
8059 // FIXME: We may still want to build some representation of this
8060 // explicit specialization.
8062 return (Decl*) nullptr;
8065 Specialization->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
8066 AttributeList *Attr = D.getDeclSpec().getAttributes().getList();
8068 ProcessDeclAttributeList(S, Specialization, Attr);
8070 if (Specialization->isDefined()) {
8071 // Let the ASTConsumer know that this function has been explicitly
8072 // instantiated now, and its linkage might have changed.
8073 Consumer.HandleTopLevelDecl(DeclGroupRef(Specialization));
8074 } else if (TSK == TSK_ExplicitInstantiationDefinition)
8075 InstantiateFunctionDefinition(D.getIdentifierLoc(), Specialization);
8077 // C++0x [temp.explicit]p2:
8078 // If the explicit instantiation is for a member function, a member class
8079 // or a static data member of a class template specialization, the name of
8080 // the class template specialization in the qualified-id for the member
8081 // name shall be a simple-template-id.
8083 // C++98 has the same restriction, just worded differently.
8084 FunctionTemplateDecl *FunTmpl = Specialization->getPrimaryTemplate();
8085 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId && !FunTmpl &&
8086 D.getCXXScopeSpec().isSet() &&
8087 !ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()))
8088 Diag(D.getIdentifierLoc(),
8089 diag::ext_explicit_instantiation_without_qualified_id)
8090 << Specialization << D.getCXXScopeSpec().getRange();
8092 // C++ Concepts TS [dcl.spec.concept]p7: A program shall not declare an
8093 // explicit instantiation (14.8.2) [...] of a concept definition.
8094 if (FunTmpl && FunTmpl->isConcept() &&
8095 !D.getDeclSpec().isConceptSpecified()) {
8096 Diag(D.getIdentifierLoc(), diag::err_concept_specialized)
8097 << 0 /*function*/ << 0 /*explicitly instantiated*/;
8098 Diag(FunTmpl->getLocation(), diag::note_previous_declaration);
8102 CheckExplicitInstantiationScope(*this,
8103 FunTmpl? (NamedDecl *)FunTmpl
8104 : Specialization->getInstantiatedFromMemberFunction(),
8105 D.getIdentifierLoc(),
8106 D.getCXXScopeSpec().isSet());
8108 // FIXME: Create some kind of ExplicitInstantiationDecl here.
8109 return (Decl*) nullptr;
8113 Sema::ActOnDependentTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
8114 const CXXScopeSpec &SS, IdentifierInfo *Name,
8115 SourceLocation TagLoc, SourceLocation NameLoc) {
8116 // This has to hold, because SS is expected to be defined.
8117 assert(Name && "Expected a name in a dependent tag");
8119 NestedNameSpecifier *NNS = SS.getScopeRep();
8123 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
8125 if (TUK == TUK_Declaration || TUK == TUK_Definition) {
8126 Diag(NameLoc, diag::err_dependent_tag_decl)
8127 << (TUK == TUK_Definition) << Kind << SS.getRange();
8131 // Create the resulting type.
8132 ElaboratedTypeKeyword Kwd = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
8133 QualType Result = Context.getDependentNameType(Kwd, NNS, Name);
8135 // Create type-source location information for this type.
8137 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(Result);
8138 TL.setElaboratedKeywordLoc(TagLoc);
8139 TL.setQualifierLoc(SS.getWithLocInContext(Context));
8140 TL.setNameLoc(NameLoc);
8141 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
8145 Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc,
8146 const CXXScopeSpec &SS, const IdentifierInfo &II,
8147 SourceLocation IdLoc) {
8151 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
8153 getLangOpts().CPlusPlus11 ?
8154 diag::warn_cxx98_compat_typename_outside_of_template :
8155 diag::ext_typename_outside_of_template)
8156 << FixItHint::CreateRemoval(TypenameLoc);
8158 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
8159 QualType T = CheckTypenameType(TypenameLoc.isValid()? ETK_Typename : ETK_None,
8160 TypenameLoc, QualifierLoc, II, IdLoc);
8164 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
8165 if (isa<DependentNameType>(T)) {
8166 DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
8167 TL.setElaboratedKeywordLoc(TypenameLoc);
8168 TL.setQualifierLoc(QualifierLoc);
8169 TL.setNameLoc(IdLoc);
8171 ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>();
8172 TL.setElaboratedKeywordLoc(TypenameLoc);
8173 TL.setQualifierLoc(QualifierLoc);
8174 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
8177 return CreateParsedType(T, TSI);
8181 Sema::ActOnTypenameType(Scope *S,
8182 SourceLocation TypenameLoc,
8183 const CXXScopeSpec &SS,
8184 SourceLocation TemplateKWLoc,
8185 TemplateTy TemplateIn,
8186 SourceLocation TemplateNameLoc,
8187 SourceLocation LAngleLoc,
8188 ASTTemplateArgsPtr TemplateArgsIn,
8189 SourceLocation RAngleLoc) {
8190 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
8192 getLangOpts().CPlusPlus11 ?
8193 diag::warn_cxx98_compat_typename_outside_of_template :
8194 diag::ext_typename_outside_of_template)
8195 << FixItHint::CreateRemoval(TypenameLoc);
8197 // Translate the parser's template argument list in our AST format.
8198 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
8199 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
8201 TemplateName Template = TemplateIn.get();
8202 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
8203 // Construct a dependent template specialization type.
8204 assert(DTN && "dependent template has non-dependent name?");
8205 assert(DTN->getQualifier() == SS.getScopeRep());
8206 QualType T = Context.getDependentTemplateSpecializationType(ETK_Typename,
8207 DTN->getQualifier(),
8208 DTN->getIdentifier(),
8211 // Create source-location information for this type.
8212 TypeLocBuilder Builder;
8213 DependentTemplateSpecializationTypeLoc SpecTL
8214 = Builder.push<DependentTemplateSpecializationTypeLoc>(T);
8215 SpecTL.setElaboratedKeywordLoc(TypenameLoc);
8216 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
8217 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
8218 SpecTL.setTemplateNameLoc(TemplateNameLoc);
8219 SpecTL.setLAngleLoc(LAngleLoc);
8220 SpecTL.setRAngleLoc(RAngleLoc);
8221 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
8222 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
8223 return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
8226 QualType T = CheckTemplateIdType(Template, TemplateNameLoc, TemplateArgs);
8230 // Provide source-location information for the template specialization type.
8231 TypeLocBuilder Builder;
8232 TemplateSpecializationTypeLoc SpecTL
8233 = Builder.push<TemplateSpecializationTypeLoc>(T);
8234 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
8235 SpecTL.setTemplateNameLoc(TemplateNameLoc);
8236 SpecTL.setLAngleLoc(LAngleLoc);
8237 SpecTL.setRAngleLoc(RAngleLoc);
8238 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
8239 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
8241 T = Context.getElaboratedType(ETK_Typename, SS.getScopeRep(), T);
8242 ElaboratedTypeLoc TL = Builder.push<ElaboratedTypeLoc>(T);
8243 TL.setElaboratedKeywordLoc(TypenameLoc);
8244 TL.setQualifierLoc(SS.getWithLocInContext(Context));
8246 TypeSourceInfo *TSI = Builder.getTypeSourceInfo(Context, T);
8247 return CreateParsedType(T, TSI);
8251 /// Determine whether this failed name lookup should be treated as being
8252 /// disabled by a usage of std::enable_if.
8253 static bool isEnableIf(NestedNameSpecifierLoc NNS, const IdentifierInfo &II,
8254 SourceRange &CondRange) {
8255 // We must be looking for a ::type...
8256 if (!II.isStr("type"))
8259 // ... within an explicitly-written template specialization...
8260 if (!NNS || !NNS.getNestedNameSpecifier()->getAsType())
8262 TypeLoc EnableIfTy = NNS.getTypeLoc();
8263 TemplateSpecializationTypeLoc EnableIfTSTLoc =
8264 EnableIfTy.getAs<TemplateSpecializationTypeLoc>();
8265 if (!EnableIfTSTLoc || EnableIfTSTLoc.getNumArgs() == 0)
8267 const TemplateSpecializationType *EnableIfTST =
8268 cast<TemplateSpecializationType>(EnableIfTSTLoc.getTypePtr());
8270 // ... which names a complete class template declaration...
8271 const TemplateDecl *EnableIfDecl =
8272 EnableIfTST->getTemplateName().getAsTemplateDecl();
8273 if (!EnableIfDecl || EnableIfTST->isIncompleteType())
8276 // ... called "enable_if".
8277 const IdentifierInfo *EnableIfII =
8278 EnableIfDecl->getDeclName().getAsIdentifierInfo();
8279 if (!EnableIfII || !EnableIfII->isStr("enable_if"))
8282 // Assume the first template argument is the condition.
8283 CondRange = EnableIfTSTLoc.getArgLoc(0).getSourceRange();
8287 /// \brief Build the type that describes a C++ typename specifier,
8288 /// e.g., "typename T::type".
8290 Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword,
8291 SourceLocation KeywordLoc,
8292 NestedNameSpecifierLoc QualifierLoc,
8293 const IdentifierInfo &II,
8294 SourceLocation IILoc) {
8296 SS.Adopt(QualifierLoc);
8298 DeclContext *Ctx = computeDeclContext(SS);
8300 // If the nested-name-specifier is dependent and couldn't be
8301 // resolved to a type, build a typename type.
8302 assert(QualifierLoc.getNestedNameSpecifier()->isDependent());
8303 return Context.getDependentNameType(Keyword,
8304 QualifierLoc.getNestedNameSpecifier(),
8308 // If the nested-name-specifier refers to the current instantiation,
8309 // the "typename" keyword itself is superfluous. In C++03, the
8310 // program is actually ill-formed. However, DR 382 (in C++0x CD1)
8311 // allows such extraneous "typename" keywords, and we retroactively
8312 // apply this DR to C++03 code with only a warning. In any case we continue.
8314 if (RequireCompleteDeclContext(SS, Ctx))
8317 DeclarationName Name(&II);
8318 LookupResult Result(*this, Name, IILoc, LookupOrdinaryName);
8319 LookupQualifiedName(Result, Ctx, SS);
8320 unsigned DiagID = 0;
8321 Decl *Referenced = nullptr;
8322 switch (Result.getResultKind()) {
8323 case LookupResult::NotFound: {
8324 // If we're looking up 'type' within a template named 'enable_if', produce
8325 // a more specific diagnostic.
8326 SourceRange CondRange;
8327 if (isEnableIf(QualifierLoc, II, CondRange)) {
8328 Diag(CondRange.getBegin(), diag::err_typename_nested_not_found_enable_if)
8329 << Ctx << CondRange;
8333 DiagID = diag::err_typename_nested_not_found;
8337 case LookupResult::FoundUnresolvedValue: {
8338 // We found a using declaration that is a value. Most likely, the using
8339 // declaration itself is meant to have the 'typename' keyword.
8340 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
8342 Diag(IILoc, diag::err_typename_refers_to_using_value_decl)
8343 << Name << Ctx << FullRange;
8344 if (UnresolvedUsingValueDecl *Using
8345 = dyn_cast<UnresolvedUsingValueDecl>(Result.getRepresentativeDecl())){
8346 SourceLocation Loc = Using->getQualifierLoc().getBeginLoc();
8347 Diag(Loc, diag::note_using_value_decl_missing_typename)
8348 << FixItHint::CreateInsertion(Loc, "typename ");
8351 // Fall through to create a dependent typename type, from which we can recover
8354 case LookupResult::NotFoundInCurrentInstantiation:
8355 // Okay, it's a member of an unknown instantiation.
8356 return Context.getDependentNameType(Keyword,
8357 QualifierLoc.getNestedNameSpecifier(),
8360 case LookupResult::Found:
8361 if (TypeDecl *Type = dyn_cast<TypeDecl>(Result.getFoundDecl())) {
8362 // We found a type. Build an ElaboratedType, since the
8363 // typename-specifier was just sugar.
8364 MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
8365 return Context.getElaboratedType(ETK_Typename,
8366 QualifierLoc.getNestedNameSpecifier(),
8367 Context.getTypeDeclType(Type));
8370 DiagID = diag::err_typename_nested_not_type;
8371 Referenced = Result.getFoundDecl();
8374 case LookupResult::FoundOverloaded:
8375 DiagID = diag::err_typename_nested_not_type;
8376 Referenced = *Result.begin();
8379 case LookupResult::Ambiguous:
8383 // If we get here, it's because name lookup did not find a
8384 // type. Emit an appropriate diagnostic and return an error.
8385 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
8387 Diag(IILoc, DiagID) << FullRange << Name << Ctx;
8389 Diag(Referenced->getLocation(), diag::note_typename_refers_here)
8395 // See Sema::RebuildTypeInCurrentInstantiation
8396 class CurrentInstantiationRebuilder
8397 : public TreeTransform<CurrentInstantiationRebuilder> {
8399 DeclarationName Entity;
8402 typedef TreeTransform<CurrentInstantiationRebuilder> inherited;
8404 CurrentInstantiationRebuilder(Sema &SemaRef,
8406 DeclarationName Entity)
8407 : TreeTransform<CurrentInstantiationRebuilder>(SemaRef),
8408 Loc(Loc), Entity(Entity) { }
8410 /// \brief Determine whether the given type \p T has already been
8413 /// For the purposes of type reconstruction, a type has already been
8414 /// transformed if it is NULL or if it is not dependent.
8415 bool AlreadyTransformed(QualType T) {
8416 return T.isNull() || !T->isDependentType();
8419 /// \brief Returns the location of the entity whose type is being
8421 SourceLocation getBaseLocation() { return Loc; }
8423 /// \brief Returns the name of the entity whose type is being rebuilt.
8424 DeclarationName getBaseEntity() { return Entity; }
8426 /// \brief Sets the "base" location and entity when that
8427 /// information is known based on another transformation.
8428 void setBase(SourceLocation Loc, DeclarationName Entity) {
8430 this->Entity = Entity;
8433 ExprResult TransformLambdaExpr(LambdaExpr *E) {
8434 // Lambdas never need to be transformed.
8438 } // end anonymous namespace
8440 /// \brief Rebuilds a type within the context of the current instantiation.
8442 /// The type \p T is part of the type of an out-of-line member definition of
8443 /// a class template (or class template partial specialization) that was parsed
8444 /// and constructed before we entered the scope of the class template (or
8445 /// partial specialization thereof). This routine will rebuild that type now
8446 /// that we have entered the declarator's scope, which may produce different
8447 /// canonical types, e.g.,
8450 /// template<typename T>
8452 /// typedef T* pointer;
8456 /// template<typename T>
8457 /// typename X<T>::pointer X<T>::data() { ... }
8460 /// Here, the type "typename X<T>::pointer" will be created as a DependentNameType,
8461 /// since we do not know that we can look into X<T> when we parsed the type.
8462 /// This function will rebuild the type, performing the lookup of "pointer"
8463 /// in X<T> and returning an ElaboratedType whose canonical type is the same
8464 /// as the canonical type of T*, allowing the return types of the out-of-line
8465 /// definition and the declaration to match.
8466 TypeSourceInfo *Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo *T,
8468 DeclarationName Name) {
8469 if (!T || !T->getType()->isDependentType())
8472 CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name);
8473 return Rebuilder.TransformType(T);
8476 ExprResult Sema::RebuildExprInCurrentInstantiation(Expr *E) {
8477 CurrentInstantiationRebuilder Rebuilder(*this, E->getExprLoc(),
8479 return Rebuilder.TransformExpr(E);
8482 bool Sema::RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS) {
8486 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
8487 CurrentInstantiationRebuilder Rebuilder(*this, SS.getRange().getBegin(),
8489 NestedNameSpecifierLoc Rebuilt
8490 = Rebuilder.TransformNestedNameSpecifierLoc(QualifierLoc);
8498 /// \brief Rebuild the template parameters now that we know we're in a current
8500 bool Sema::RebuildTemplateParamsInCurrentInstantiation(
8501 TemplateParameterList *Params) {
8502 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
8503 Decl *Param = Params->getParam(I);
8505 // There is nothing to rebuild in a type parameter.
8506 if (isa<TemplateTypeParmDecl>(Param))
8509 // Rebuild the template parameter list of a template template parameter.
8510 if (TemplateTemplateParmDecl *TTP
8511 = dyn_cast<TemplateTemplateParmDecl>(Param)) {
8512 if (RebuildTemplateParamsInCurrentInstantiation(
8513 TTP->getTemplateParameters()))
8519 // Rebuild the type of a non-type template parameter.
8520 NonTypeTemplateParmDecl *NTTP = cast<NonTypeTemplateParmDecl>(Param);
8521 TypeSourceInfo *NewTSI
8522 = RebuildTypeInCurrentInstantiation(NTTP->getTypeSourceInfo(),
8523 NTTP->getLocation(),
8524 NTTP->getDeclName());
8528 if (NewTSI != NTTP->getTypeSourceInfo()) {
8529 NTTP->setTypeSourceInfo(NewTSI);
8530 NTTP->setType(NewTSI->getType());
8537 /// \brief Produces a formatted string that describes the binding of
8538 /// template parameters to template arguments.
8540 Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
8541 const TemplateArgumentList &Args) {
8542 return getTemplateArgumentBindingsText(Params, Args.data(), Args.size());
8546 Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
8547 const TemplateArgument *Args,
8549 SmallString<128> Str;
8550 llvm::raw_svector_ostream Out(Str);
8552 if (!Params || Params->size() == 0 || NumArgs == 0)
8553 return std::string();
8555 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
8564 if (const IdentifierInfo *Id = Params->getParam(I)->getIdentifier()) {
8565 Out << Id->getName();
8571 Args[I].print(getPrintingPolicy(), Out);
8578 void Sema::MarkAsLateParsedTemplate(FunctionDecl *FD, Decl *FnD,
8579 CachedTokens &Toks) {
8583 LateParsedTemplate *LPT = new LateParsedTemplate;
8585 // Take tokens to avoid allocations
8586 LPT->Toks.swap(Toks);
8588 LateParsedTemplateMap.insert(std::make_pair(FD, LPT));
8590 FD->setLateTemplateParsed(true);
8593 void Sema::UnmarkAsLateParsedTemplate(FunctionDecl *FD) {
8596 FD->setLateTemplateParsed(false);
8599 bool Sema::IsInsideALocalClassWithinATemplateFunction() {
8600 DeclContext *DC = CurContext;
8603 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(CurContext)) {
8604 const FunctionDecl *FD = RD->isLocalClass();
8605 return (FD && FD->getTemplatedKind() != FunctionDecl::TK_NonTemplate);
8606 } else if (DC->isTranslationUnit() || DC->isNamespace())
8609 DC = DC->getParent();
8614 /// \brief Walk the path from which a declaration was instantiated, and check
8615 /// that every explicit specialization along that path is visible. This enforces
8616 /// C++ [temp.expl.spec]/6:
8618 /// If a template, a member template or a member of a class template is
8619 /// explicitly specialized then that specialization shall be declared before
8620 /// the first use of that specialization that would cause an implicit
8621 /// instantiation to take place, in every translation unit in which such a
8622 /// use occurs; no diagnostic is required.
8624 /// and also C++ [temp.class.spec]/1:
8626 /// A partial specialization shall be declared before the first use of a
8627 /// class template specialization that would make use of the partial
8628 /// specialization as the result of an implicit or explicit instantiation
8629 /// in every translation unit in which such a use occurs; no diagnostic is
8631 class ExplicitSpecializationVisibilityChecker {
8634 llvm::SmallVector<Module *, 8> Modules;
8637 ExplicitSpecializationVisibilityChecker(Sema &S, SourceLocation Loc)
8640 void check(NamedDecl *ND) {
8641 if (auto *FD = dyn_cast<FunctionDecl>(ND))
8642 return checkImpl(FD);
8643 if (auto *RD = dyn_cast<CXXRecordDecl>(ND))
8644 return checkImpl(RD);
8645 if (auto *VD = dyn_cast<VarDecl>(ND))
8646 return checkImpl(VD);
8647 if (auto *ED = dyn_cast<EnumDecl>(ND))
8648 return checkImpl(ED);
8652 void diagnose(NamedDecl *D, bool IsPartialSpec) {
8653 auto Kind = IsPartialSpec ? Sema::MissingImportKind::PartialSpecialization
8654 : Sema::MissingImportKind::ExplicitSpecialization;
8655 const bool Recover = true;
8657 // If we got a custom set of modules (because only a subset of the
8658 // declarations are interesting), use them, otherwise let
8659 // diagnoseMissingImport intelligently pick some.
8660 if (Modules.empty())
8661 S.diagnoseMissingImport(Loc, D, Kind, Recover);
8663 S.diagnoseMissingImport(Loc, D, D->getLocation(), Modules, Kind, Recover);
8666 // Check a specific declaration. There are three problematic cases:
8668 // 1) The declaration is an explicit specialization of a template
8670 // 2) The declaration is an explicit specialization of a member of an
8672 // 3) The declaration is an instantiation of a template, and that template
8673 // is an explicit specialization of a member of a templated class.
8675 // We don't need to go any deeper than that, as the instantiation of the
8676 // surrounding class / etc is not triggered by whatever triggered this
8677 // instantiation, and thus should be checked elsewhere.
8678 template<typename SpecDecl>
8679 void checkImpl(SpecDecl *Spec) {
8680 bool IsHiddenExplicitSpecialization = false;
8681 if (Spec->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) {
8682 IsHiddenExplicitSpecialization =
8683 Spec->getMemberSpecializationInfo()
8684 ? !S.hasVisibleMemberSpecialization(Spec, &Modules)
8685 : !S.hasVisibleDeclaration(Spec);
8687 checkInstantiated(Spec);
8690 if (IsHiddenExplicitSpecialization)
8691 diagnose(Spec->getMostRecentDecl(), false);
8694 void checkInstantiated(FunctionDecl *FD) {
8695 if (auto *TD = FD->getPrimaryTemplate())
8699 void checkInstantiated(CXXRecordDecl *RD) {
8700 auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(RD);
8704 auto From = SD->getSpecializedTemplateOrPartial();
8705 if (auto *TD = From.dyn_cast<ClassTemplateDecl *>())
8708 From.dyn_cast<ClassTemplatePartialSpecializationDecl *>()) {
8709 if (!S.hasVisibleDeclaration(TD))
8715 void checkInstantiated(VarDecl *RD) {
8716 auto *SD = dyn_cast<VarTemplateSpecializationDecl>(RD);
8720 auto From = SD->getSpecializedTemplateOrPartial();
8721 if (auto *TD = From.dyn_cast<VarTemplateDecl *>())
8724 From.dyn_cast<VarTemplatePartialSpecializationDecl *>()) {
8725 if (!S.hasVisibleDeclaration(TD))
8731 void checkInstantiated(EnumDecl *FD) {}
8733 template<typename TemplDecl>
8734 void checkTemplate(TemplDecl *TD) {
8735 if (TD->isMemberSpecialization()) {
8736 if (!S.hasVisibleMemberSpecialization(TD, &Modules))
8737 diagnose(TD->getMostRecentDecl(), false);
8742 void Sema::checkSpecializationVisibility(SourceLocation Loc, NamedDecl *Spec) {
8743 if (!getLangOpts().Modules)
8746 ExplicitSpecializationVisibilityChecker(*this, Loc).check(Spec);
8749 /// \brief Check whether a template partial specialization that we've discovered
8750 /// is hidden, and produce suitable diagnostics if so.
8751 void Sema::checkPartialSpecializationVisibility(SourceLocation Loc,
8753 llvm::SmallVector<Module *, 8> Modules;
8754 if (!hasVisibleDeclaration(Spec, &Modules))
8755 diagnoseMissingImport(Loc, Spec, Spec->getLocation(), Modules,
8756 MissingImportKind::PartialSpecialization,