1 //===------- SemaTemplate.cpp - Semantic Analysis for C++ Templates -------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //===----------------------------------------------------------------------===//
8 // This file implements semantic analysis for C++ templates.
9 //===----------------------------------------------------------------------===//
11 #include "TreeTransform.h"
12 #include "clang/AST/ASTConsumer.h"
13 #include "clang/AST/ASTContext.h"
14 #include "clang/AST/Decl.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/TemplateName.h"
21 #include "clang/AST/TypeVisitor.h"
22 #include "clang/Basic/Builtins.h"
23 #include "clang/Basic/DiagnosticSema.h"
24 #include "clang/Basic/LangOptions.h"
25 #include "clang/Basic/PartialDiagnostic.h"
26 #include "clang/Basic/SourceLocation.h"
27 #include "clang/Basic/Stack.h"
28 #include "clang/Basic/TargetInfo.h"
29 #include "clang/Sema/DeclSpec.h"
30 #include "clang/Sema/EnterExpressionEvaluationContext.h"
31 #include "clang/Sema/Initialization.h"
32 #include "clang/Sema/Lookup.h"
33 #include "clang/Sema/Overload.h"
34 #include "clang/Sema/ParsedTemplate.h"
35 #include "clang/Sema/Scope.h"
36 #include "clang/Sema/SemaInternal.h"
37 #include "clang/Sema/Template.h"
38 #include "clang/Sema/TemplateDeduction.h"
39 #include "llvm/ADT/SmallBitVector.h"
40 #include "llvm/ADT/SmallString.h"
41 #include "llvm/ADT/StringExtras.h"
45 using namespace clang
;
48 // Exported for use by Parser.
50 clang::getTemplateParamsRange(TemplateParameterList
const * const *Ps
,
52 if (!N
) return SourceRange();
53 return SourceRange(Ps
[0]->getTemplateLoc(), Ps
[N
-1]->getRAngleLoc());
56 unsigned Sema::getTemplateDepth(Scope
*S
) const {
59 // Each template parameter scope represents one level of template parameter
61 for (Scope
*TempParamScope
= S
->getTemplateParamParent(); TempParamScope
;
62 TempParamScope
= TempParamScope
->getParent()->getTemplateParamParent()) {
66 // Note that there are template parameters with the given depth.
67 auto ParamsAtDepth
= [&](unsigned D
) { Depth
= std::max(Depth
, D
+ 1); };
69 // Look for parameters of an enclosing generic lambda. We don't create a
70 // template parameter scope for these.
71 for (FunctionScopeInfo
*FSI
: getFunctionScopes()) {
72 if (auto *LSI
= dyn_cast
<LambdaScopeInfo
>(FSI
)) {
73 if (!LSI
->TemplateParams
.empty()) {
74 ParamsAtDepth(LSI
->AutoTemplateParameterDepth
);
77 if (LSI
->GLTemplateParameterList
) {
78 ParamsAtDepth(LSI
->GLTemplateParameterList
->getDepth());
84 // Look for parameters of an enclosing terse function template. We don't
85 // create a template parameter scope for these either.
86 for (const InventedTemplateParameterInfo
&Info
:
87 getInventedParameterInfos()) {
88 if (!Info
.TemplateParams
.empty()) {
89 ParamsAtDepth(Info
.AutoTemplateParameterDepth
);
97 /// \brief Determine whether the declaration found is acceptable as the name
98 /// of a template and, if so, return that template declaration. Otherwise,
101 /// Note that this may return an UnresolvedUsingValueDecl if AllowDependent
102 /// is true. In all other cases it will return a TemplateDecl (or null).
103 NamedDecl
*Sema::getAsTemplateNameDecl(NamedDecl
*D
,
104 bool AllowFunctionTemplates
,
105 bool AllowDependent
) {
106 D
= D
->getUnderlyingDecl();
108 if (isa
<TemplateDecl
>(D
)) {
109 if (!AllowFunctionTemplates
&& isa
<FunctionTemplateDecl
>(D
))
115 if (const auto *Record
= dyn_cast
<CXXRecordDecl
>(D
)) {
116 // C++ [temp.local]p1:
117 // Like normal (non-template) classes, class templates have an
118 // injected-class-name (Clause 9). The injected-class-name
119 // can be used with or without a template-argument-list. When
120 // it is used without a template-argument-list, it is
121 // equivalent to the injected-class-name followed by the
122 // template-parameters of the class template enclosed in
123 // <>. When it is used with a template-argument-list, it
124 // refers to the specified class template specialization,
125 // which could be the current specialization or another
127 if (Record
->isInjectedClassName()) {
128 Record
= cast
<CXXRecordDecl
>(Record
->getDeclContext());
129 if (Record
->getDescribedClassTemplate())
130 return Record
->getDescribedClassTemplate();
132 if (const auto *Spec
= dyn_cast
<ClassTemplateSpecializationDecl
>(Record
))
133 return Spec
->getSpecializedTemplate();
139 // 'using Dependent::foo;' can resolve to a template name.
140 // 'using typename Dependent::foo;' cannot (not even if 'foo' is an
141 // injected-class-name).
142 if (AllowDependent
&& isa
<UnresolvedUsingValueDecl
>(D
))
148 void Sema::FilterAcceptableTemplateNames(LookupResult
&R
,
149 bool AllowFunctionTemplates
,
150 bool AllowDependent
) {
151 LookupResult::Filter filter
= R
.makeFilter();
152 while (filter
.hasNext()) {
153 NamedDecl
*Orig
= filter
.next();
154 if (!getAsTemplateNameDecl(Orig
, AllowFunctionTemplates
, AllowDependent
))
160 bool Sema::hasAnyAcceptableTemplateNames(LookupResult
&R
,
161 bool AllowFunctionTemplates
,
163 bool AllowNonTemplateFunctions
) {
164 for (LookupResult::iterator I
= R
.begin(), IEnd
= R
.end(); I
!= IEnd
; ++I
) {
165 if (getAsTemplateNameDecl(*I
, AllowFunctionTemplates
, AllowDependent
))
167 if (AllowNonTemplateFunctions
&&
168 isa
<FunctionDecl
>((*I
)->getUnderlyingDecl()))
175 TemplateNameKind
Sema::isTemplateName(Scope
*S
,
177 bool hasTemplateKeyword
,
178 const UnqualifiedId
&Name
,
179 ParsedType ObjectTypePtr
,
180 bool EnteringContext
,
181 TemplateTy
&TemplateResult
,
182 bool &MemberOfUnknownSpecialization
,
183 bool Disambiguation
) {
184 assert(getLangOpts().CPlusPlus
&& "No template names in C!");
186 DeclarationName TName
;
187 MemberOfUnknownSpecialization
= false;
189 switch (Name
.getKind()) {
190 case UnqualifiedIdKind::IK_Identifier
:
191 TName
= DeclarationName(Name
.Identifier
);
194 case UnqualifiedIdKind::IK_OperatorFunctionId
:
195 TName
= Context
.DeclarationNames
.getCXXOperatorName(
196 Name
.OperatorFunctionId
.Operator
);
199 case UnqualifiedIdKind::IK_LiteralOperatorId
:
200 TName
= Context
.DeclarationNames
.getCXXLiteralOperatorName(Name
.Identifier
);
204 return TNK_Non_template
;
207 QualType ObjectType
= ObjectTypePtr
.get();
209 AssumedTemplateKind AssumedTemplate
;
210 LookupResult
R(*this, TName
, Name
.getBeginLoc(), LookupOrdinaryName
);
211 if (LookupTemplateName(R
, S
, SS
, ObjectType
, EnteringContext
,
212 MemberOfUnknownSpecialization
, SourceLocation(),
214 /*AllowTypoCorrection=*/!Disambiguation
))
215 return TNK_Non_template
;
217 if (AssumedTemplate
!= AssumedTemplateKind::None
) {
218 TemplateResult
= TemplateTy::make(Context
.getAssumedTemplateName(TName
));
219 // Let the parser know whether we found nothing or found functions; if we
220 // found nothing, we want to more carefully check whether this is actually
221 // a function template name versus some other kind of undeclared identifier.
222 return AssumedTemplate
== AssumedTemplateKind::FoundNothing
223 ? TNK_Undeclared_template
224 : TNK_Function_template
;
228 return TNK_Non_template
;
230 NamedDecl
*D
= nullptr;
231 UsingShadowDecl
*FoundUsingShadow
= dyn_cast
<UsingShadowDecl
>(*R
.begin());
232 if (R
.isAmbiguous()) {
233 // If we got an ambiguity involving a non-function template, treat this
234 // as a template name, and pick an arbitrary template for error recovery.
235 bool AnyFunctionTemplates
= false;
236 for (NamedDecl
*FoundD
: R
) {
237 if (NamedDecl
*FoundTemplate
= getAsTemplateNameDecl(FoundD
)) {
238 if (isa
<FunctionTemplateDecl
>(FoundTemplate
))
239 AnyFunctionTemplates
= true;
242 FoundUsingShadow
= dyn_cast
<UsingShadowDecl
>(FoundD
);
248 // If we didn't find any templates at all, this isn't a template name.
249 // Leave the ambiguity for a later lookup to diagnose.
250 if (!D
&& !AnyFunctionTemplates
) {
251 R
.suppressDiagnostics();
252 return TNK_Non_template
;
255 // If the only templates were function templates, filter out the rest.
256 // We'll diagnose the ambiguity later.
258 FilterAcceptableTemplateNames(R
);
261 // At this point, we have either picked a single template name declaration D
262 // or we have a non-empty set of results R containing either one template name
263 // declaration or a set of function templates.
265 TemplateName Template
;
266 TemplateNameKind TemplateKind
;
268 unsigned ResultCount
= R
.end() - R
.begin();
269 if (!D
&& ResultCount
> 1) {
270 // We assume that we'll preserve the qualifier from a function
271 // template name in other ways.
272 Template
= Context
.getOverloadedTemplateName(R
.begin(), R
.end());
273 TemplateKind
= TNK_Function_template
;
275 // We'll do this lookup again later.
276 R
.suppressDiagnostics();
279 D
= getAsTemplateNameDecl(*R
.begin());
280 assert(D
&& "unambiguous result is not a template name");
283 if (isa
<UnresolvedUsingValueDecl
>(D
)) {
284 // We don't yet know whether this is a template-name or not.
285 MemberOfUnknownSpecialization
= true;
286 return TNK_Non_template
;
289 TemplateDecl
*TD
= cast
<TemplateDecl
>(D
);
291 FoundUsingShadow
? TemplateName(FoundUsingShadow
) : TemplateName(TD
);
292 assert(!FoundUsingShadow
|| FoundUsingShadow
->getTargetDecl() == TD
);
293 if (SS
.isSet() && !SS
.isInvalid()) {
294 NestedNameSpecifier
*Qualifier
= SS
.getScopeRep();
295 Template
= Context
.getQualifiedTemplateName(Qualifier
, hasTemplateKeyword
,
299 if (isa
<FunctionTemplateDecl
>(TD
)) {
300 TemplateKind
= TNK_Function_template
;
302 // We'll do this lookup again later.
303 R
.suppressDiagnostics();
305 assert(isa
<ClassTemplateDecl
>(TD
) || isa
<TemplateTemplateParmDecl
>(TD
) ||
306 isa
<TypeAliasTemplateDecl
>(TD
) || isa
<VarTemplateDecl
>(TD
) ||
307 isa
<BuiltinTemplateDecl
>(TD
) || isa
<ConceptDecl
>(TD
));
309 isa
<VarTemplateDecl
>(TD
) ? TNK_Var_template
:
310 isa
<ConceptDecl
>(TD
) ? TNK_Concept_template
:
315 TemplateResult
= TemplateTy::make(Template
);
319 bool Sema::isDeductionGuideName(Scope
*S
, const IdentifierInfo
&Name
,
320 SourceLocation NameLoc
, CXXScopeSpec
&SS
,
321 ParsedTemplateTy
*Template
/*=nullptr*/) {
322 bool MemberOfUnknownSpecialization
= false;
324 // We could use redeclaration lookup here, but we don't need to: the
325 // syntactic form of a deduction guide is enough to identify it even
326 // if we can't look up the template name at all.
327 LookupResult
R(*this, DeclarationName(&Name
), NameLoc
, LookupOrdinaryName
);
328 if (LookupTemplateName(R
, S
, SS
, /*ObjectType*/ QualType(),
329 /*EnteringContext*/ false,
330 MemberOfUnknownSpecialization
))
333 if (R
.empty()) return false;
334 if (R
.isAmbiguous()) {
335 // FIXME: Diagnose an ambiguity if we find at least one template.
336 R
.suppressDiagnostics();
340 // We only treat template-names that name type templates as valid deduction
342 TemplateDecl
*TD
= R
.getAsSingle
<TemplateDecl
>();
343 if (!TD
|| !getAsTypeTemplateDecl(TD
))
347 *Template
= TemplateTy::make(TemplateName(TD
));
351 bool Sema::DiagnoseUnknownTemplateName(const IdentifierInfo
&II
,
352 SourceLocation IILoc
,
354 const CXXScopeSpec
*SS
,
355 TemplateTy
&SuggestedTemplate
,
356 TemplateNameKind
&SuggestedKind
) {
357 // We can't recover unless there's a dependent scope specifier preceding the
359 // FIXME: Typo correction?
360 if (!SS
|| !SS
->isSet() || !isDependentScopeSpecifier(*SS
) ||
361 computeDeclContext(*SS
))
364 // The code is missing a 'template' keyword prior to the dependent template
366 NestedNameSpecifier
*Qualifier
= (NestedNameSpecifier
*)SS
->getScopeRep();
367 Diag(IILoc
, diag::err_template_kw_missing
)
368 << Qualifier
<< II
.getName()
369 << FixItHint::CreateInsertion(IILoc
, "template ");
371 = TemplateTy::make(Context
.getDependentTemplateName(Qualifier
, &II
));
372 SuggestedKind
= TNK_Dependent_template_name
;
376 bool Sema::LookupTemplateName(LookupResult
&Found
,
377 Scope
*S
, CXXScopeSpec
&SS
,
379 bool EnteringContext
,
380 bool &MemberOfUnknownSpecialization
,
381 RequiredTemplateKind RequiredTemplate
,
382 AssumedTemplateKind
*ATK
,
383 bool AllowTypoCorrection
) {
385 *ATK
= AssumedTemplateKind::None
;
390 Found
.setTemplateNameLookup(true);
392 // Determine where to perform name lookup
393 MemberOfUnknownSpecialization
= false;
394 DeclContext
*LookupCtx
= nullptr;
395 bool IsDependent
= false;
396 if (!ObjectType
.isNull()) {
397 // This nested-name-specifier occurs in a member access expression, e.g.,
398 // x->B::f, and we are looking into the type of the object.
399 assert(SS
.isEmpty() && "ObjectType and scope specifier cannot coexist");
400 LookupCtx
= computeDeclContext(ObjectType
);
401 IsDependent
= !LookupCtx
&& ObjectType
->isDependentType();
402 assert((IsDependent
|| !ObjectType
->isIncompleteType() ||
403 !ObjectType
->getAs
<TagType
>() ||
404 ObjectType
->castAs
<TagType
>()->isBeingDefined()) &&
405 "Caller should have completed object type");
407 // Template names cannot appear inside an Objective-C class or object type
410 // FIXME: This is wrong. For example:
412 // template<typename T> using Vec = T __attribute__((ext_vector_type(4)));
414 // vi.Vec<int>::~Vec<int>();
416 // ... should be accepted but we will not treat 'Vec' as a template name
417 // here. The right thing to do would be to check if the name is a valid
418 // vector component name, and look up a template name if not. And similarly
419 // for lookups into Objective-C class and object types, where the same
420 // problem can arise.
421 if (ObjectType
->isObjCObjectOrInterfaceType() ||
422 ObjectType
->isVectorType()) {
426 } else if (SS
.isNotEmpty()) {
427 // This nested-name-specifier occurs after another nested-name-specifier,
428 // so long into the context associated with the prior nested-name-specifier.
429 LookupCtx
= computeDeclContext(SS
, EnteringContext
);
430 IsDependent
= !LookupCtx
&& isDependentScopeSpecifier(SS
);
432 // The declaration context must be complete.
433 if (LookupCtx
&& RequireCompleteDeclContext(SS
, LookupCtx
))
437 bool ObjectTypeSearchedInScope
= false;
438 bool AllowFunctionTemplatesInLookup
= true;
440 // Perform "qualified" name lookup into the declaration context we
441 // computed, which is either the type of the base of a member access
442 // expression or the declaration context associated with a prior
443 // nested-name-specifier.
444 LookupQualifiedName(Found
, LookupCtx
);
446 // FIXME: The C++ standard does not clearly specify what happens in the
447 // case where the object type is dependent, and implementations vary. In
448 // Clang, we treat a name after a . or -> as a template-name if lookup
449 // finds a non-dependent member or member of the current instantiation that
450 // is a type template, or finds no such members and lookup in the context
451 // of the postfix-expression finds a type template. In the latter case, the
452 // name is nonetheless dependent, and we may resolve it to a member of an
453 // unknown specialization when we come to instantiate the template.
454 IsDependent
|= Found
.wasNotFoundInCurrentInstantiation();
457 if (SS
.isEmpty() && (ObjectType
.isNull() || Found
.empty())) {
458 // C++ [basic.lookup.classref]p1:
459 // In a class member access expression (5.2.5), if the . or -> token is
460 // immediately followed by an identifier followed by a <, the
461 // identifier must be looked up to determine whether the < is the
462 // beginning of a template argument list (14.2) or a less-than operator.
463 // The identifier is first looked up in the class of the object
464 // expression. If the identifier is not found, it is then looked up in
465 // the context of the entire postfix-expression and shall name a class
468 LookupName(Found
, S
);
470 if (!ObjectType
.isNull()) {
471 // FIXME: We should filter out all non-type templates here, particularly
472 // variable templates and concepts. But the exclusion of alias templates
473 // and template template parameters is a wording defect.
474 AllowFunctionTemplatesInLookup
= false;
475 ObjectTypeSearchedInScope
= true;
478 IsDependent
|= Found
.wasNotFoundInCurrentInstantiation();
481 if (Found
.isAmbiguous())
484 if (ATK
&& SS
.isEmpty() && ObjectType
.isNull() &&
485 !RequiredTemplate
.hasTemplateKeyword()) {
486 // C++2a [temp.names]p2:
487 // A name is also considered to refer to a template if it is an
488 // unqualified-id followed by a < and name lookup finds either one or more
489 // functions or finds nothing.
491 // To keep our behavior consistent, we apply the "finds nothing" part in
492 // all language modes, and diagnose the empty lookup in ActOnCallExpr if we
493 // successfully form a call to an undeclared template-id.
495 getLangOpts().CPlusPlus20
&& llvm::all_of(Found
, [](NamedDecl
*ND
) {
496 return isa
<FunctionDecl
>(ND
->getUnderlyingDecl());
498 if (AllFunctions
|| (Found
.empty() && !IsDependent
)) {
499 // If lookup found any functions, or if this is a name that can only be
500 // used for a function, then strongly assume this is a function
502 *ATK
= (Found
.empty() && Found
.getLookupName().isIdentifier())
503 ? AssumedTemplateKind::FoundNothing
504 : AssumedTemplateKind::FoundFunctions
;
510 if (Found
.empty() && !IsDependent
&& AllowTypoCorrection
) {
511 // If we did not find any names, and this is not a disambiguation, attempt
512 // to correct any typos.
513 DeclarationName Name
= Found
.getLookupName();
515 // Simple filter callback that, for keywords, only accepts the C++ *_cast
516 DefaultFilterCCC FilterCCC
{};
517 FilterCCC
.WantTypeSpecifiers
= false;
518 FilterCCC
.WantExpressionKeywords
= false;
519 FilterCCC
.WantRemainingKeywords
= false;
520 FilterCCC
.WantCXXNamedCasts
= true;
521 if (TypoCorrection Corrected
=
522 CorrectTypo(Found
.getLookupNameInfo(), Found
.getLookupKind(), S
,
523 &SS
, FilterCCC
, CTK_ErrorRecovery
, LookupCtx
)) {
524 if (auto *ND
= Corrected
.getFoundDecl())
526 FilterAcceptableTemplateNames(Found
);
527 if (Found
.isAmbiguous()) {
529 } else if (!Found
.empty()) {
530 Found
.setLookupName(Corrected
.getCorrection());
532 std::string
CorrectedStr(Corrected
.getAsString(getLangOpts()));
533 bool DroppedSpecifier
= Corrected
.WillReplaceSpecifier() &&
534 Name
.getAsString() == CorrectedStr
;
535 diagnoseTypo(Corrected
, PDiag(diag::err_no_member_template_suggest
)
536 << Name
<< LookupCtx
<< DroppedSpecifier
539 diagnoseTypo(Corrected
, PDiag(diag::err_no_template_suggest
) << Name
);
545 NamedDecl
*ExampleLookupResult
=
546 Found
.empty() ? nullptr : Found
.getRepresentativeDecl();
547 FilterAcceptableTemplateNames(Found
, AllowFunctionTemplatesInLookup
);
550 MemberOfUnknownSpecialization
= true;
554 // If a 'template' keyword was used, a lookup that finds only non-template
555 // names is an error.
556 if (ExampleLookupResult
&& RequiredTemplate
) {
557 Diag(Found
.getNameLoc(), diag::err_template_kw_refers_to_non_template
)
558 << Found
.getLookupName() << SS
.getRange()
559 << RequiredTemplate
.hasTemplateKeyword()
560 << RequiredTemplate
.getTemplateKeywordLoc();
561 Diag(ExampleLookupResult
->getUnderlyingDecl()->getLocation(),
562 diag::note_template_kw_refers_to_non_template
)
563 << Found
.getLookupName();
570 if (S
&& !ObjectType
.isNull() && !ObjectTypeSearchedInScope
&&
571 !getLangOpts().CPlusPlus11
) {
572 // C++03 [basic.lookup.classref]p1:
573 // [...] If the lookup in the class of the object expression finds a
574 // template, the name is also looked up in the context of the entire
575 // postfix-expression and [...]
577 // Note: C++11 does not perform this second lookup.
578 LookupResult
FoundOuter(*this, Found
.getLookupName(), Found
.getNameLoc(),
580 FoundOuter
.setTemplateNameLookup(true);
581 LookupName(FoundOuter
, S
);
582 // FIXME: We silently accept an ambiguous lookup here, in violation of
584 FilterAcceptableTemplateNames(FoundOuter
, /*AllowFunctionTemplates=*/false);
586 NamedDecl
*OuterTemplate
;
587 if (FoundOuter
.empty()) {
588 // - if the name is not found, the name found in the class of the
589 // object expression is used, otherwise
590 } else if (FoundOuter
.isAmbiguous() || !FoundOuter
.isSingleResult() ||
592 getAsTemplateNameDecl(FoundOuter
.getFoundDecl()))) {
593 // - if the name is found in the context of the entire
594 // postfix-expression and does not name a class template, the name
595 // found in the class of the object expression is used, otherwise
597 } else if (!Found
.isSuppressingAmbiguousDiagnostics()) {
598 // - if the name found is a class template, it must refer to the same
599 // entity as the one found in the class of the object expression,
600 // otherwise the program is ill-formed.
601 if (!Found
.isSingleResult() ||
602 getAsTemplateNameDecl(Found
.getFoundDecl())->getCanonicalDecl() !=
603 OuterTemplate
->getCanonicalDecl()) {
604 Diag(Found
.getNameLoc(),
605 diag::ext_nested_name_member_ref_lookup_ambiguous
)
606 << Found
.getLookupName()
608 Diag(Found
.getRepresentativeDecl()->getLocation(),
609 diag::note_ambig_member_ref_object_type
)
611 Diag(FoundOuter
.getFoundDecl()->getLocation(),
612 diag::note_ambig_member_ref_scope
);
614 // Recover by taking the template that we found in the object
615 // expression's type.
623 void Sema::diagnoseExprIntendedAsTemplateName(Scope
*S
, ExprResult TemplateName
,
625 SourceLocation Greater
) {
626 if (TemplateName
.isInvalid())
629 DeclarationNameInfo NameInfo
;
631 LookupNameKind LookupKind
;
633 DeclContext
*LookupCtx
= nullptr;
634 NamedDecl
*Found
= nullptr;
635 bool MissingTemplateKeyword
= false;
637 // Figure out what name we looked up.
638 if (auto *DRE
= dyn_cast
<DeclRefExpr
>(TemplateName
.get())) {
639 NameInfo
= DRE
->getNameInfo();
640 SS
.Adopt(DRE
->getQualifierLoc());
641 LookupKind
= LookupOrdinaryName
;
642 Found
= DRE
->getFoundDecl();
643 } else if (auto *ME
= dyn_cast
<MemberExpr
>(TemplateName
.get())) {
644 NameInfo
= ME
->getMemberNameInfo();
645 SS
.Adopt(ME
->getQualifierLoc());
646 LookupKind
= LookupMemberName
;
647 LookupCtx
= ME
->getBase()->getType()->getAsCXXRecordDecl();
648 Found
= ME
->getMemberDecl();
649 } else if (auto *DSDRE
=
650 dyn_cast
<DependentScopeDeclRefExpr
>(TemplateName
.get())) {
651 NameInfo
= DSDRE
->getNameInfo();
652 SS
.Adopt(DSDRE
->getQualifierLoc());
653 MissingTemplateKeyword
= true;
654 } else if (auto *DSME
=
655 dyn_cast
<CXXDependentScopeMemberExpr
>(TemplateName
.get())) {
656 NameInfo
= DSME
->getMemberNameInfo();
657 SS
.Adopt(DSME
->getQualifierLoc());
658 MissingTemplateKeyword
= true;
660 llvm_unreachable("unexpected kind of potential template name");
663 // If this is a dependent-scope lookup, diagnose that the 'template' keyword
665 if (MissingTemplateKeyword
) {
666 Diag(NameInfo
.getBeginLoc(), diag::err_template_kw_missing
)
667 << "" << NameInfo
.getName().getAsString() << SourceRange(Less
, Greater
);
671 // Try to correct the name by looking for templates and C++ named casts.
672 struct TemplateCandidateFilter
: CorrectionCandidateCallback
{
674 TemplateCandidateFilter(Sema
&S
) : S(S
) {
675 WantTypeSpecifiers
= false;
676 WantExpressionKeywords
= false;
677 WantRemainingKeywords
= false;
678 WantCXXNamedCasts
= true;
680 bool ValidateCandidate(const TypoCorrection
&Candidate
) override
{
681 if (auto *ND
= Candidate
.getCorrectionDecl())
682 return S
.getAsTemplateNameDecl(ND
);
683 return Candidate
.isKeyword();
686 std::unique_ptr
<CorrectionCandidateCallback
> clone() override
{
687 return std::make_unique
<TemplateCandidateFilter
>(*this);
691 DeclarationName Name
= NameInfo
.getName();
692 TemplateCandidateFilter
CCC(*this);
693 if (TypoCorrection Corrected
= CorrectTypo(NameInfo
, LookupKind
, S
, &SS
, CCC
,
694 CTK_ErrorRecovery
, LookupCtx
)) {
695 auto *ND
= Corrected
.getFoundDecl();
697 ND
= getAsTemplateNameDecl(ND
);
698 if (ND
|| Corrected
.isKeyword()) {
700 std::string
CorrectedStr(Corrected
.getAsString(getLangOpts()));
701 bool DroppedSpecifier
= Corrected
.WillReplaceSpecifier() &&
702 Name
.getAsString() == CorrectedStr
;
703 diagnoseTypo(Corrected
,
704 PDiag(diag::err_non_template_in_member_template_id_suggest
)
705 << Name
<< LookupCtx
<< DroppedSpecifier
706 << SS
.getRange(), false);
708 diagnoseTypo(Corrected
,
709 PDiag(diag::err_non_template_in_template_id_suggest
)
713 Diag(Found
->getLocation(),
714 diag::note_non_template_in_template_id_found
);
719 Diag(NameInfo
.getLoc(), diag::err_non_template_in_template_id
)
720 << Name
<< SourceRange(Less
, Greater
);
722 Diag(Found
->getLocation(), diag::note_non_template_in_template_id_found
);
725 /// ActOnDependentIdExpression - Handle a dependent id-expression that
726 /// was just parsed. This is only possible with an explicit scope
727 /// specifier naming a dependent type.
729 Sema::ActOnDependentIdExpression(const CXXScopeSpec
&SS
,
730 SourceLocation TemplateKWLoc
,
731 const DeclarationNameInfo
&NameInfo
,
732 bool isAddressOfOperand
,
733 const TemplateArgumentListInfo
*TemplateArgs
) {
734 DeclContext
*DC
= getFunctionLevelDeclContext();
736 // C++11 [expr.prim.general]p12:
737 // An id-expression that denotes a non-static data member or non-static
738 // member function of a class can only be used:
740 // - if that id-expression denotes a non-static data member and it
741 // appears in an unevaluated operand.
743 // If this might be the case, form a DependentScopeDeclRefExpr instead of a
744 // CXXDependentScopeMemberExpr. The former can instantiate to either
745 // DeclRefExpr or MemberExpr depending on lookup results, while the latter is
746 // always a MemberExpr.
747 bool MightBeCxx11UnevalField
=
748 getLangOpts().CPlusPlus11
&& isUnevaluatedContext();
750 // Check if the nested name specifier is an enum type.
752 if (NestedNameSpecifier
*NNS
= SS
.getScopeRep())
753 IsEnum
= isa_and_nonnull
<EnumType
>(NNS
->getAsType());
755 if (!MightBeCxx11UnevalField
&& !isAddressOfOperand
&& !IsEnum
&&
756 isa
<CXXMethodDecl
>(DC
) &&
757 cast
<CXXMethodDecl
>(DC
)->isImplicitObjectMemberFunction()) {
758 QualType ThisType
= cast
<CXXMethodDecl
>(DC
)->getThisType().getNonReferenceType();
760 // Since the 'this' expression is synthesized, we don't need to
761 // perform the double-lookup check.
762 NamedDecl
*FirstQualifierInScope
= nullptr;
764 return CXXDependentScopeMemberExpr::Create(
765 Context
, /*This=*/nullptr, ThisType
,
766 /*IsArrow=*/!Context
.getLangOpts().HLSL
,
767 /*Op=*/SourceLocation(), SS
.getWithLocInContext(Context
), TemplateKWLoc
,
768 FirstQualifierInScope
, NameInfo
, TemplateArgs
);
771 return BuildDependentDeclRefExpr(SS
, TemplateKWLoc
, NameInfo
, TemplateArgs
);
775 Sema::BuildDependentDeclRefExpr(const CXXScopeSpec
&SS
,
776 SourceLocation TemplateKWLoc
,
777 const DeclarationNameInfo
&NameInfo
,
778 const TemplateArgumentListInfo
*TemplateArgs
) {
779 // DependentScopeDeclRefExpr::Create requires a valid QualifierLoc
780 NestedNameSpecifierLoc QualifierLoc
= SS
.getWithLocInContext(Context
);
784 return DependentScopeDeclRefExpr::Create(
785 Context
, QualifierLoc
, TemplateKWLoc
, NameInfo
, TemplateArgs
);
789 /// Determine whether we would be unable to instantiate this template (because
790 /// it either has no definition, or is in the process of being instantiated).
791 bool Sema::DiagnoseUninstantiableTemplate(SourceLocation PointOfInstantiation
,
792 NamedDecl
*Instantiation
,
793 bool InstantiatedFromMember
,
794 const NamedDecl
*Pattern
,
795 const NamedDecl
*PatternDef
,
796 TemplateSpecializationKind TSK
,
797 bool Complain
/*= true*/) {
798 assert(isa
<TagDecl
>(Instantiation
) || isa
<FunctionDecl
>(Instantiation
) ||
799 isa
<VarDecl
>(Instantiation
));
801 bool IsEntityBeingDefined
= false;
802 if (const TagDecl
*TD
= dyn_cast_or_null
<TagDecl
>(PatternDef
))
803 IsEntityBeingDefined
= TD
->isBeingDefined();
805 if (PatternDef
&& !IsEntityBeingDefined
) {
806 NamedDecl
*SuggestedDef
= nullptr;
807 if (!hasReachableDefinition(const_cast<NamedDecl
*>(PatternDef
),
809 /*OnlyNeedComplete*/ false)) {
810 // If we're allowed to diagnose this and recover, do so.
811 bool Recover
= Complain
&& !isSFINAEContext();
813 diagnoseMissingImport(PointOfInstantiation
, SuggestedDef
,
814 Sema::MissingImportKind::Definition
, Recover
);
820 if (!Complain
|| (PatternDef
&& PatternDef
->isInvalidDecl()))
823 QualType InstantiationTy
;
824 if (TagDecl
*TD
= dyn_cast
<TagDecl
>(Instantiation
))
825 InstantiationTy
= Context
.getTypeDeclType(TD
);
827 Diag(PointOfInstantiation
,
828 diag::err_template_instantiate_within_definition
)
829 << /*implicit|explicit*/(TSK
!= TSK_ImplicitInstantiation
)
831 // Not much point in noting the template declaration here, since
832 // we're lexically inside it.
833 Instantiation
->setInvalidDecl();
834 } else if (InstantiatedFromMember
) {
835 if (isa
<FunctionDecl
>(Instantiation
)) {
836 Diag(PointOfInstantiation
,
837 diag::err_explicit_instantiation_undefined_member
)
838 << /*member function*/ 1 << Instantiation
->getDeclName()
839 << Instantiation
->getDeclContext();
840 Diag(Pattern
->getLocation(), diag::note_explicit_instantiation_here
);
842 assert(isa
<TagDecl
>(Instantiation
) && "Must be a TagDecl!");
843 Diag(PointOfInstantiation
,
844 diag::err_implicit_instantiate_member_undefined
)
846 Diag(Pattern
->getLocation(), diag::note_member_declared_at
);
849 if (isa
<FunctionDecl
>(Instantiation
)) {
850 Diag(PointOfInstantiation
,
851 diag::err_explicit_instantiation_undefined_func_template
)
853 Diag(Pattern
->getLocation(), diag::note_explicit_instantiation_here
);
854 } else if (isa
<TagDecl
>(Instantiation
)) {
855 Diag(PointOfInstantiation
, diag::err_template_instantiate_undefined
)
856 << (TSK
!= TSK_ImplicitInstantiation
)
858 NoteTemplateLocation(*Pattern
);
860 assert(isa
<VarDecl
>(Instantiation
) && "Must be a VarDecl!");
861 if (isa
<VarTemplateSpecializationDecl
>(Instantiation
)) {
862 Diag(PointOfInstantiation
,
863 diag::err_explicit_instantiation_undefined_var_template
)
865 Instantiation
->setInvalidDecl();
867 Diag(PointOfInstantiation
,
868 diag::err_explicit_instantiation_undefined_member
)
869 << /*static data member*/ 2 << Instantiation
->getDeclName()
870 << Instantiation
->getDeclContext();
871 Diag(Pattern
->getLocation(), diag::note_explicit_instantiation_here
);
875 // In general, Instantiation isn't marked invalid to get more than one
876 // error for multiple undefined instantiations. But the code that does
877 // explicit declaration -> explicit definition conversion can't handle
878 // invalid declarations, so mark as invalid in that case.
879 if (TSK
== TSK_ExplicitInstantiationDeclaration
)
880 Instantiation
->setInvalidDecl();
884 /// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining
885 /// that the template parameter 'PrevDecl' is being shadowed by a new
886 /// declaration at location Loc. Returns true to indicate that this is
887 /// an error, and false otherwise.
888 void Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc
, Decl
*PrevDecl
) {
889 assert(PrevDecl
->isTemplateParameter() && "Not a template parameter");
891 // C++ [temp.local]p4:
892 // A template-parameter shall not be redeclared within its
893 // scope (including nested scopes).
895 // Make this a warning when MSVC compatibility is requested.
896 unsigned DiagId
= getLangOpts().MSVCCompat
? diag::ext_template_param_shadow
897 : diag::err_template_param_shadow
;
898 const auto *ND
= cast
<NamedDecl
>(PrevDecl
);
899 Diag(Loc
, DiagId
) << ND
->getDeclName();
900 NoteTemplateParameterLocation(*ND
);
903 /// AdjustDeclIfTemplate - If the given decl happens to be a template, reset
904 /// the parameter D to reference the templated declaration and return a pointer
905 /// to the template declaration. Otherwise, do nothing to D and return null.
906 TemplateDecl
*Sema::AdjustDeclIfTemplate(Decl
*&D
) {
907 if (TemplateDecl
*Temp
= dyn_cast_or_null
<TemplateDecl
>(D
)) {
908 D
= Temp
->getTemplatedDecl();
914 ParsedTemplateArgument
ParsedTemplateArgument::getTemplatePackExpansion(
915 SourceLocation EllipsisLoc
) const {
916 assert(Kind
== Template
&&
917 "Only template template arguments can be pack expansions here");
918 assert(getAsTemplate().get().containsUnexpandedParameterPack() &&
919 "Template template argument pack expansion without packs");
920 ParsedTemplateArgument
Result(*this);
921 Result
.EllipsisLoc
= EllipsisLoc
;
925 static TemplateArgumentLoc
translateTemplateArgument(Sema
&SemaRef
,
926 const ParsedTemplateArgument
&Arg
) {
928 switch (Arg
.getKind()) {
929 case ParsedTemplateArgument::Type
: {
931 QualType T
= SemaRef
.GetTypeFromParser(Arg
.getAsType(), &DI
);
933 DI
= SemaRef
.Context
.getTrivialTypeSourceInfo(T
, Arg
.getLocation());
934 return TemplateArgumentLoc(TemplateArgument(T
), DI
);
937 case ParsedTemplateArgument::NonType
: {
938 Expr
*E
= static_cast<Expr
*>(Arg
.getAsExpr());
939 return TemplateArgumentLoc(TemplateArgument(E
), E
);
942 case ParsedTemplateArgument::Template
: {
943 TemplateName Template
= Arg
.getAsTemplate().get();
944 TemplateArgument TArg
;
945 if (Arg
.getEllipsisLoc().isValid())
946 TArg
= TemplateArgument(Template
, std::optional
<unsigned int>());
949 return TemplateArgumentLoc(
950 SemaRef
.Context
, TArg
,
951 Arg
.getScopeSpec().getWithLocInContext(SemaRef
.Context
),
952 Arg
.getLocation(), Arg
.getEllipsisLoc());
956 llvm_unreachable("Unhandled parsed template argument");
959 /// Translates template arguments as provided by the parser
960 /// into template arguments used by semantic analysis.
961 void Sema::translateTemplateArguments(const ASTTemplateArgsPtr
&TemplateArgsIn
,
962 TemplateArgumentListInfo
&TemplateArgs
) {
963 for (unsigned I
= 0, Last
= TemplateArgsIn
.size(); I
!= Last
; ++I
)
964 TemplateArgs
.addArgument(translateTemplateArgument(*this,
968 static void maybeDiagnoseTemplateParameterShadow(Sema
&SemaRef
, Scope
*S
,
970 IdentifierInfo
*Name
) {
971 NamedDecl
*PrevDecl
= SemaRef
.LookupSingleName(
972 S
, Name
, Loc
, Sema::LookupOrdinaryName
, Sema::ForVisibleRedeclaration
);
973 if (PrevDecl
&& PrevDecl
->isTemplateParameter())
974 SemaRef
.DiagnoseTemplateParameterShadow(Loc
, PrevDecl
);
977 /// Convert a parsed type into a parsed template argument. This is mostly
978 /// trivial, except that we may have parsed a C++17 deduced class template
979 /// specialization type, in which case we should form a template template
980 /// argument instead of a type template argument.
981 ParsedTemplateArgument
Sema::ActOnTemplateTypeArgument(TypeResult ParsedType
) {
982 TypeSourceInfo
*TInfo
;
983 QualType T
= GetTypeFromParser(ParsedType
.get(), &TInfo
);
985 return ParsedTemplateArgument();
986 assert(TInfo
&& "template argument with no location");
988 // If we might have formed a deduced template specialization type, convert
989 // it to a template template argument.
990 if (getLangOpts().CPlusPlus17
) {
991 TypeLoc TL
= TInfo
->getTypeLoc();
992 SourceLocation EllipsisLoc
;
993 if (auto PET
= TL
.getAs
<PackExpansionTypeLoc
>()) {
994 EllipsisLoc
= PET
.getEllipsisLoc();
995 TL
= PET
.getPatternLoc();
999 if (auto ET
= TL
.getAs
<ElaboratedTypeLoc
>()) {
1000 SS
.Adopt(ET
.getQualifierLoc());
1001 TL
= ET
.getNamedTypeLoc();
1004 if (auto DTST
= TL
.getAs
<DeducedTemplateSpecializationTypeLoc
>()) {
1005 TemplateName Name
= DTST
.getTypePtr()->getTemplateName();
1007 Name
= Context
.getQualifiedTemplateName(SS
.getScopeRep(),
1008 /*HasTemplateKeyword=*/false,
1010 ParsedTemplateArgument
Result(SS
, TemplateTy::make(Name
),
1011 DTST
.getTemplateNameLoc());
1012 if (EllipsisLoc
.isValid())
1013 Result
= Result
.getTemplatePackExpansion(EllipsisLoc
);
1018 // This is a normal type template argument. Note, if the type template
1019 // argument is an injected-class-name for a template, it has a dual nature
1020 // and can be used as either a type or a template. We handle that in
1021 // convertTypeTemplateArgumentToTemplate.
1022 return ParsedTemplateArgument(ParsedTemplateArgument::Type
,
1023 ParsedType
.get().getAsOpaquePtr(),
1024 TInfo
->getTypeLoc().getBeginLoc());
1027 /// ActOnTypeParameter - Called when a C++ template type parameter
1028 /// (e.g., "typename T") has been parsed. Typename specifies whether
1029 /// the keyword "typename" was used to declare the type parameter
1030 /// (otherwise, "class" was used), and KeyLoc is the location of the
1031 /// "class" or "typename" keyword. ParamName is the name of the
1032 /// parameter (NULL indicates an unnamed template parameter) and
1033 /// ParamNameLoc is the location of the parameter name (if any).
1034 /// If the type parameter has a default argument, it will be added
1035 /// later via ActOnTypeParameterDefault.
1036 NamedDecl
*Sema::ActOnTypeParameter(Scope
*S
, bool Typename
,
1037 SourceLocation EllipsisLoc
,
1038 SourceLocation KeyLoc
,
1039 IdentifierInfo
*ParamName
,
1040 SourceLocation ParamNameLoc
,
1041 unsigned Depth
, unsigned Position
,
1042 SourceLocation EqualLoc
,
1043 ParsedType DefaultArg
,
1044 bool HasTypeConstraint
) {
1045 assert(S
->isTemplateParamScope() &&
1046 "Template type parameter not in template parameter scope!");
1048 bool IsParameterPack
= EllipsisLoc
.isValid();
1049 TemplateTypeParmDecl
*Param
1050 = TemplateTypeParmDecl::Create(Context
, Context
.getTranslationUnitDecl(),
1051 KeyLoc
, ParamNameLoc
, Depth
, Position
,
1052 ParamName
, Typename
, IsParameterPack
,
1054 Param
->setAccess(AS_public
);
1056 if (Param
->isParameterPack())
1057 if (auto *LSI
= getEnclosingLambda())
1058 LSI
->LocalPacks
.push_back(Param
);
1061 maybeDiagnoseTemplateParameterShadow(*this, S
, ParamNameLoc
, ParamName
);
1063 // Add the template parameter into the current scope.
1065 IdResolver
.AddDecl(Param
);
1068 // C++0x [temp.param]p9:
1069 // A default template-argument may be specified for any kind of
1070 // template-parameter that is not a template parameter pack.
1071 if (DefaultArg
&& IsParameterPack
) {
1072 Diag(EqualLoc
, diag::err_template_param_pack_default_arg
);
1073 DefaultArg
= nullptr;
1076 // Handle the default argument, if provided.
1078 TypeSourceInfo
*DefaultTInfo
;
1079 GetTypeFromParser(DefaultArg
, &DefaultTInfo
);
1081 assert(DefaultTInfo
&& "expected source information for type");
1083 // Check for unexpanded parameter packs.
1084 if (DiagnoseUnexpandedParameterPack(ParamNameLoc
, DefaultTInfo
,
1085 UPPC_DefaultArgument
))
1088 // Check the template argument itself.
1089 if (CheckTemplateArgument(DefaultTInfo
)) {
1090 Param
->setInvalidDecl();
1094 Param
->setDefaultArgument(DefaultTInfo
);
1100 /// Convert the parser's template argument list representation into our form.
1101 static TemplateArgumentListInfo
1102 makeTemplateArgumentListInfo(Sema
&S
, TemplateIdAnnotation
&TemplateId
) {
1103 TemplateArgumentListInfo
TemplateArgs(TemplateId
.LAngleLoc
,
1104 TemplateId
.RAngleLoc
);
1105 ASTTemplateArgsPtr
TemplateArgsPtr(TemplateId
.getTemplateArgs(),
1106 TemplateId
.NumArgs
);
1107 S
.translateTemplateArguments(TemplateArgsPtr
, TemplateArgs
);
1108 return TemplateArgs
;
1111 bool Sema::CheckTypeConstraint(TemplateIdAnnotation
*TypeConstr
) {
1113 TemplateName TN
= TypeConstr
->Template
.get();
1114 ConceptDecl
*CD
= cast
<ConceptDecl
>(TN
.getAsTemplateDecl());
1116 // C++2a [temp.param]p4:
1117 // [...] The concept designated by a type-constraint shall be a type
1118 // concept ([temp.concept]).
1119 if (!CD
->isTypeConcept()) {
1120 Diag(TypeConstr
->TemplateNameLoc
,
1121 diag::err_type_constraint_non_type_concept
);
1125 bool WereArgsSpecified
= TypeConstr
->LAngleLoc
.isValid();
1127 if (!WereArgsSpecified
&&
1128 CD
->getTemplateParameters()->getMinRequiredArguments() > 1) {
1129 Diag(TypeConstr
->TemplateNameLoc
,
1130 diag::err_type_constraint_missing_arguments
)
1137 bool Sema::ActOnTypeConstraint(const CXXScopeSpec
&SS
,
1138 TemplateIdAnnotation
*TypeConstr
,
1139 TemplateTypeParmDecl
*ConstrainedParameter
,
1140 SourceLocation EllipsisLoc
) {
1141 return BuildTypeConstraint(SS
, TypeConstr
, ConstrainedParameter
, EllipsisLoc
,
1145 bool Sema::BuildTypeConstraint(const CXXScopeSpec
&SS
,
1146 TemplateIdAnnotation
*TypeConstr
,
1147 TemplateTypeParmDecl
*ConstrainedParameter
,
1148 SourceLocation EllipsisLoc
,
1149 bool AllowUnexpandedPack
) {
1151 if (CheckTypeConstraint(TypeConstr
))
1154 TemplateName TN
= TypeConstr
->Template
.get();
1155 ConceptDecl
*CD
= cast
<ConceptDecl
>(TN
.getAsTemplateDecl());
1157 DeclarationNameInfo
ConceptName(DeclarationName(TypeConstr
->Name
),
1158 TypeConstr
->TemplateNameLoc
);
1160 TemplateArgumentListInfo TemplateArgs
;
1161 if (TypeConstr
->LAngleLoc
.isValid()) {
1163 makeTemplateArgumentListInfo(*this, *TypeConstr
);
1165 if (EllipsisLoc
.isInvalid() && !AllowUnexpandedPack
) {
1166 for (TemplateArgumentLoc Arg
: TemplateArgs
.arguments()) {
1167 if (DiagnoseUnexpandedParameterPack(Arg
, UPPC_TypeConstraint
))
1172 return AttachTypeConstraint(
1173 SS
.isSet() ? SS
.getWithLocInContext(Context
) : NestedNameSpecifierLoc(),
1175 TypeConstr
->LAngleLoc
.isValid() ? &TemplateArgs
: nullptr,
1176 ConstrainedParameter
, EllipsisLoc
);
1179 template<typename ArgumentLocAppender
>
1180 static ExprResult
formImmediatelyDeclaredConstraint(
1181 Sema
&S
, NestedNameSpecifierLoc NS
, DeclarationNameInfo NameInfo
,
1182 ConceptDecl
*NamedConcept
, SourceLocation LAngleLoc
,
1183 SourceLocation RAngleLoc
, QualType ConstrainedType
,
1184 SourceLocation ParamNameLoc
, ArgumentLocAppender Appender
,
1185 SourceLocation EllipsisLoc
) {
1187 TemplateArgumentListInfo ConstraintArgs
;
1188 ConstraintArgs
.addArgument(
1189 S
.getTrivialTemplateArgumentLoc(TemplateArgument(ConstrainedType
),
1190 /*NTTPType=*/QualType(), ParamNameLoc
));
1192 ConstraintArgs
.setRAngleLoc(RAngleLoc
);
1193 ConstraintArgs
.setLAngleLoc(LAngleLoc
);
1194 Appender(ConstraintArgs
);
1196 // C++2a [temp.param]p4:
1197 // [...] This constraint-expression E is called the immediately-declared
1198 // constraint of T. [...]
1201 ExprResult ImmediatelyDeclaredConstraint
= S
.CheckConceptTemplateId(
1202 SS
, /*TemplateKWLoc=*/SourceLocation(), NameInfo
,
1203 /*FoundDecl=*/NamedConcept
, NamedConcept
, &ConstraintArgs
);
1204 if (ImmediatelyDeclaredConstraint
.isInvalid() || !EllipsisLoc
.isValid())
1205 return ImmediatelyDeclaredConstraint
;
1207 // C++2a [temp.param]p4:
1208 // [...] If T is not a pack, then E is E', otherwise E is (E' && ...).
1210 // We have the following case:
1212 // template<typename T> concept C1 = true;
1213 // template<C1... T> struct s1;
1215 // The constraint: (C1<T> && ...)
1217 // Note that the type of C1<T> is known to be 'bool', so we don't need to do
1218 // any unqualified lookups for 'operator&&' here.
1219 return S
.BuildCXXFoldExpr(/*UnqualifiedLookup=*/nullptr,
1220 /*LParenLoc=*/SourceLocation(),
1221 ImmediatelyDeclaredConstraint
.get(), BO_LAnd
,
1222 EllipsisLoc
, /*RHS=*/nullptr,
1223 /*RParenLoc=*/SourceLocation(),
1224 /*NumExpansions=*/std::nullopt
);
1227 /// Attach a type-constraint to a template parameter.
1228 /// \returns true if an error occurred. This can happen if the
1229 /// immediately-declared constraint could not be formed (e.g. incorrect number
1230 /// of arguments for the named concept).
1231 bool Sema::AttachTypeConstraint(NestedNameSpecifierLoc NS
,
1232 DeclarationNameInfo NameInfo
,
1233 ConceptDecl
*NamedConcept
,
1234 const TemplateArgumentListInfo
*TemplateArgs
,
1235 TemplateTypeParmDecl
*ConstrainedParameter
,
1236 SourceLocation EllipsisLoc
) {
1237 // C++2a [temp.param]p4:
1238 // [...] If Q is of the form C<A1, ..., An>, then let E' be
1239 // C<T, A1, ..., An>. Otherwise, let E' be C<T>. [...]
1240 const ASTTemplateArgumentListInfo
*ArgsAsWritten
=
1241 TemplateArgs
? ASTTemplateArgumentListInfo::Create(Context
,
1242 *TemplateArgs
) : nullptr;
1244 QualType
ParamAsArgument(ConstrainedParameter
->getTypeForDecl(), 0);
1246 ExprResult ImmediatelyDeclaredConstraint
=
1247 formImmediatelyDeclaredConstraint(
1248 *this, NS
, NameInfo
, NamedConcept
,
1249 TemplateArgs
? TemplateArgs
->getLAngleLoc() : SourceLocation(),
1250 TemplateArgs
? TemplateArgs
->getRAngleLoc() : SourceLocation(),
1251 ParamAsArgument
, ConstrainedParameter
->getLocation(),
1252 [&] (TemplateArgumentListInfo
&ConstraintArgs
) {
1254 for (const auto &ArgLoc
: TemplateArgs
->arguments())
1255 ConstraintArgs
.addArgument(ArgLoc
);
1257 if (ImmediatelyDeclaredConstraint
.isInvalid())
1260 auto *CL
= ConceptReference::Create(Context
, /*NNS=*/NS
,
1261 /*TemplateKWLoc=*/SourceLocation
{},
1262 /*ConceptNameInfo=*/NameInfo
,
1263 /*FoundDecl=*/NamedConcept
,
1264 /*NamedConcept=*/NamedConcept
,
1265 /*ArgsWritten=*/ArgsAsWritten
);
1266 ConstrainedParameter
->setTypeConstraint(CL
,
1267 ImmediatelyDeclaredConstraint
.get());
1271 bool Sema::AttachTypeConstraint(AutoTypeLoc TL
,
1272 NonTypeTemplateParmDecl
*NewConstrainedParm
,
1273 NonTypeTemplateParmDecl
*OrigConstrainedParm
,
1274 SourceLocation EllipsisLoc
) {
1275 if (NewConstrainedParm
->getType() != TL
.getType() ||
1276 TL
.getAutoKeyword() != AutoTypeKeyword::Auto
) {
1277 Diag(NewConstrainedParm
->getTypeSourceInfo()->getTypeLoc().getBeginLoc(),
1278 diag::err_unsupported_placeholder_constraint
)
1279 << NewConstrainedParm
->getTypeSourceInfo()
1284 // FIXME: Concepts: This should be the type of the placeholder, but this is
1285 // unclear in the wording right now.
1287 BuildDeclRefExpr(OrigConstrainedParm
, OrigConstrainedParm
->getType(),
1288 VK_PRValue
, OrigConstrainedParm
->getLocation());
1291 ExprResult ImmediatelyDeclaredConstraint
= formImmediatelyDeclaredConstraint(
1292 *this, TL
.getNestedNameSpecifierLoc(), TL
.getConceptNameInfo(),
1293 TL
.getNamedConcept(), TL
.getLAngleLoc(), TL
.getRAngleLoc(),
1294 BuildDecltypeType(Ref
), OrigConstrainedParm
->getLocation(),
1295 [&](TemplateArgumentListInfo
&ConstraintArgs
) {
1296 for (unsigned I
= 0, C
= TL
.getNumArgs(); I
!= C
; ++I
)
1297 ConstraintArgs
.addArgument(TL
.getArgLoc(I
));
1300 if (ImmediatelyDeclaredConstraint
.isInvalid() ||
1301 !ImmediatelyDeclaredConstraint
.isUsable())
1304 NewConstrainedParm
->setPlaceholderTypeConstraint(
1305 ImmediatelyDeclaredConstraint
.get());
1309 /// Check that the type of a non-type template parameter is
1312 /// \returns the (possibly-promoted) parameter type if valid;
1313 /// otherwise, produces a diagnostic and returns a NULL type.
1314 QualType
Sema::CheckNonTypeTemplateParameterType(TypeSourceInfo
*&TSI
,
1315 SourceLocation Loc
) {
1316 if (TSI
->getType()->isUndeducedType()) {
1317 // C++17 [temp.dep.expr]p3:
1318 // An id-expression is type-dependent if it contains
1319 // - an identifier associated by name lookup with a non-type
1320 // template-parameter declared with a type that contains a
1321 // placeholder type (7.1.7.4),
1322 TSI
= SubstAutoTypeSourceInfoDependent(TSI
);
1325 return CheckNonTypeTemplateParameterType(TSI
->getType(), Loc
);
1328 /// Require the given type to be a structural type, and diagnose if it is not.
1330 /// \return \c true if an error was produced.
1331 bool Sema::RequireStructuralType(QualType T
, SourceLocation Loc
) {
1332 if (T
->isDependentType())
1335 if (RequireCompleteType(Loc
, T
, diag::err_template_nontype_parm_incomplete
))
1338 if (T
->isStructuralType())
1341 // Structural types are required to be object types or lvalue references.
1342 if (T
->isRValueReferenceType()) {
1343 Diag(Loc
, diag::err_template_nontype_parm_rvalue_ref
) << T
;
1347 // Don't mention structural types in our diagnostic prior to C++20. Also,
1348 // there's not much more we can say about non-scalar non-class types --
1349 // because we can't see functions or arrays here, those can only be language
1351 if (!getLangOpts().CPlusPlus20
||
1352 (!T
->isScalarType() && !T
->isRecordType())) {
1353 Diag(Loc
, diag::err_template_nontype_parm_bad_type
) << T
;
1357 // Structural types are required to be literal types.
1358 if (RequireLiteralType(Loc
, T
, diag::err_template_nontype_parm_not_literal
))
1361 Diag(Loc
, diag::err_template_nontype_parm_not_structural
) << T
;
1363 // Drill down into the reason why the class is non-structural.
1364 while (const CXXRecordDecl
*RD
= T
->getAsCXXRecordDecl()) {
1365 // All members are required to be public and non-mutable, and can't be of
1366 // rvalue reference type. Check these conditions first to prefer a "local"
1367 // reason over a more distant one.
1368 for (const FieldDecl
*FD
: RD
->fields()) {
1369 if (FD
->getAccess() != AS_public
) {
1370 Diag(FD
->getLocation(), diag::note_not_structural_non_public
) << T
<< 0;
1373 if (FD
->isMutable()) {
1374 Diag(FD
->getLocation(), diag::note_not_structural_mutable_field
) << T
;
1377 if (FD
->getType()->isRValueReferenceType()) {
1378 Diag(FD
->getLocation(), diag::note_not_structural_rvalue_ref_field
)
1384 // All bases are required to be public.
1385 for (const auto &BaseSpec
: RD
->bases()) {
1386 if (BaseSpec
.getAccessSpecifier() != AS_public
) {
1387 Diag(BaseSpec
.getBaseTypeLoc(), diag::note_not_structural_non_public
)
1393 // All subobjects are required to be of structural types.
1394 SourceLocation SubLoc
;
1398 for (const FieldDecl
*FD
: RD
->fields()) {
1399 QualType T
= Context
.getBaseElementType(FD
->getType());
1400 if (!T
->isStructuralType()) {
1401 SubLoc
= FD
->getLocation();
1409 for (const auto &BaseSpec
: RD
->bases()) {
1410 QualType T
= BaseSpec
.getType();
1411 if (!T
->isStructuralType()) {
1412 SubLoc
= BaseSpec
.getBaseTypeLoc();
1420 assert(Kind
!= -1 && "couldn't find reason why type is not structural");
1421 Diag(SubLoc
, diag::note_not_structural_subobject
)
1422 << T
<< Kind
<< SubType
;
1424 RD
= T
->getAsCXXRecordDecl();
1430 QualType
Sema::CheckNonTypeTemplateParameterType(QualType T
,
1431 SourceLocation Loc
) {
1432 // We don't allow variably-modified types as the type of non-type template
1434 if (T
->isVariablyModifiedType()) {
1435 Diag(Loc
, diag::err_variably_modified_nontype_template_param
)
1440 // C++ [temp.param]p4:
1442 // A non-type template-parameter shall have one of the following
1443 // (optionally cv-qualified) types:
1445 // -- integral or enumeration type,
1446 if (T
->isIntegralOrEnumerationType() ||
1447 // -- pointer to object or pointer to function,
1448 T
->isPointerType() ||
1449 // -- lvalue reference to object or lvalue reference to function,
1450 T
->isLValueReferenceType() ||
1451 // -- pointer to member,
1452 T
->isMemberPointerType() ||
1453 // -- std::nullptr_t, or
1454 T
->isNullPtrType() ||
1455 // -- a type that contains a placeholder type.
1456 T
->isUndeducedType()) {
1457 // C++ [temp.param]p5: The top-level cv-qualifiers on the template-parameter
1458 // are ignored when determining its type.
1459 return T
.getUnqualifiedType();
1462 // C++ [temp.param]p8:
1464 // A non-type template-parameter of type "array of T" or
1465 // "function returning T" is adjusted to be of type "pointer to
1466 // T" or "pointer to function returning T", respectively.
1467 if (T
->isArrayType() || T
->isFunctionType())
1468 return Context
.getDecayedType(T
);
1470 // If T is a dependent type, we can't do the check now, so we
1471 // assume that it is well-formed. Note that stripping off the
1472 // qualifiers here is not really correct if T turns out to be
1473 // an array type, but we'll recompute the type everywhere it's
1474 // used during instantiation, so that should be OK. (Using the
1475 // qualified type is equally wrong.)
1476 if (T
->isDependentType())
1477 return T
.getUnqualifiedType();
1479 // C++20 [temp.param]p6:
1480 // -- a structural type
1481 if (RequireStructuralType(T
, Loc
))
1484 if (!getLangOpts().CPlusPlus20
) {
1485 // FIXME: Consider allowing structural types as an extension in C++17. (In
1486 // earlier language modes, the template argument evaluation rules are too
1488 Diag(Loc
, diag::err_template_nontype_parm_bad_structural_type
) << T
;
1492 Diag(Loc
, diag::warn_cxx17_compat_template_nontype_parm_type
) << T
;
1493 return T
.getUnqualifiedType();
1496 NamedDecl
*Sema::ActOnNonTypeTemplateParameter(Scope
*S
, Declarator
&D
,
1499 SourceLocation EqualLoc
,
1501 TypeSourceInfo
*TInfo
= GetTypeForDeclarator(D
, S
);
1503 // Check that we have valid decl-specifiers specified.
1504 auto CheckValidDeclSpecifiers
= [this, &D
] {
1507 // template-parameter:
1509 // parameter-declaration
1511 // ... A storage class shall not be specified in a template-parameter
1514 // The typedef specifier [...] shall not be used in the decl-specifier-seq
1515 // of a parameter-declaration
1516 const DeclSpec
&DS
= D
.getDeclSpec();
1517 auto EmitDiag
= [this](SourceLocation Loc
) {
1518 Diag(Loc
, diag::err_invalid_decl_specifier_in_nontype_parm
)
1519 << FixItHint::CreateRemoval(Loc
);
1521 if (DS
.getStorageClassSpec() != DeclSpec::SCS_unspecified
)
1522 EmitDiag(DS
.getStorageClassSpecLoc());
1524 if (DS
.getThreadStorageClassSpec() != TSCS_unspecified
)
1525 EmitDiag(DS
.getThreadStorageClassSpecLoc());
1528 // The inline specifier can be applied only to the declaration or
1529 // definition of a variable or function.
1531 if (DS
.isInlineSpecified())
1532 EmitDiag(DS
.getInlineSpecLoc());
1534 // [dcl.constexpr]p1:
1535 // The constexpr specifier shall be applied only to the definition of a
1536 // variable or variable template or the declaration of a function or
1537 // function template.
1539 if (DS
.hasConstexprSpecifier())
1540 EmitDiag(DS
.getConstexprSpecLoc());
1542 // [dcl.fct.spec]p1:
1543 // Function-specifiers can be used only in function declarations.
1545 if (DS
.isVirtualSpecified())
1546 EmitDiag(DS
.getVirtualSpecLoc());
1548 if (DS
.hasExplicitSpecifier())
1549 EmitDiag(DS
.getExplicitSpecLoc());
1551 if (DS
.isNoreturnSpecified())
1552 EmitDiag(DS
.getNoreturnSpecLoc());
1555 CheckValidDeclSpecifiers();
1557 if (const auto *T
= TInfo
->getType()->getContainedDeducedType())
1558 if (isa
<AutoType
>(T
))
1559 Diag(D
.getIdentifierLoc(),
1560 diag::warn_cxx14_compat_template_nontype_parm_auto_type
)
1561 << QualType(TInfo
->getType()->getContainedAutoType(), 0);
1563 assert(S
->isTemplateParamScope() &&
1564 "Non-type template parameter not in template parameter scope!");
1565 bool Invalid
= false;
1567 QualType T
= CheckNonTypeTemplateParameterType(TInfo
, D
.getIdentifierLoc());
1569 T
= Context
.IntTy
; // Recover with an 'int' type.
1573 CheckFunctionOrTemplateParamDeclarator(S
, D
);
1575 IdentifierInfo
*ParamName
= D
.getIdentifier();
1576 bool IsParameterPack
= D
.hasEllipsis();
1577 NonTypeTemplateParmDecl
*Param
= NonTypeTemplateParmDecl::Create(
1578 Context
, Context
.getTranslationUnitDecl(), D
.getBeginLoc(),
1579 D
.getIdentifierLoc(), Depth
, Position
, ParamName
, T
, IsParameterPack
,
1581 Param
->setAccess(AS_public
);
1583 if (AutoTypeLoc TL
= TInfo
->getTypeLoc().getContainedAutoTypeLoc())
1584 if (TL
.isConstrained())
1585 if (AttachTypeConstraint(TL
, Param
, Param
, D
.getEllipsisLoc()))
1589 Param
->setInvalidDecl();
1591 if (Param
->isParameterPack())
1592 if (auto *LSI
= getEnclosingLambda())
1593 LSI
->LocalPacks
.push_back(Param
);
1596 maybeDiagnoseTemplateParameterShadow(*this, S
, D
.getIdentifierLoc(),
1599 // Add the template parameter into the current scope.
1601 IdResolver
.AddDecl(Param
);
1604 // C++0x [temp.param]p9:
1605 // A default template-argument may be specified for any kind of
1606 // template-parameter that is not a template parameter pack.
1607 if (Default
&& IsParameterPack
) {
1608 Diag(EqualLoc
, diag::err_template_param_pack_default_arg
);
1612 // Check the well-formedness of the default template argument, if provided.
1614 // Check for unexpanded parameter packs.
1615 if (DiagnoseUnexpandedParameterPack(Default
, UPPC_DefaultArgument
))
1618 Param
->setDefaultArgument(Default
);
1624 /// ActOnTemplateTemplateParameter - Called when a C++ template template
1625 /// parameter (e.g. T in template <template \<typename> class T> class array)
1626 /// has been parsed. S is the current scope.
1627 NamedDecl
*Sema::ActOnTemplateTemplateParameter(Scope
* S
,
1628 SourceLocation TmpLoc
,
1629 TemplateParameterList
*Params
,
1630 SourceLocation EllipsisLoc
,
1631 IdentifierInfo
*Name
,
1632 SourceLocation NameLoc
,
1635 SourceLocation EqualLoc
,
1636 ParsedTemplateArgument Default
) {
1637 assert(S
->isTemplateParamScope() &&
1638 "Template template parameter not in template parameter scope!");
1640 // Construct the parameter object.
1641 bool IsParameterPack
= EllipsisLoc
.isValid();
1642 TemplateTemplateParmDecl
*Param
=
1643 TemplateTemplateParmDecl::Create(Context
, Context
.getTranslationUnitDecl(),
1644 NameLoc
.isInvalid()? TmpLoc
: NameLoc
,
1645 Depth
, Position
, IsParameterPack
,
1647 Param
->setAccess(AS_public
);
1649 if (Param
->isParameterPack())
1650 if (auto *LSI
= getEnclosingLambda())
1651 LSI
->LocalPacks
.push_back(Param
);
1653 // If the template template parameter has a name, then link the identifier
1654 // into the scope and lookup mechanisms.
1656 maybeDiagnoseTemplateParameterShadow(*this, S
, NameLoc
, Name
);
1659 IdResolver
.AddDecl(Param
);
1662 if (Params
->size() == 0) {
1663 Diag(Param
->getLocation(), diag::err_template_template_parm_no_parms
)
1664 << SourceRange(Params
->getLAngleLoc(), Params
->getRAngleLoc());
1665 Param
->setInvalidDecl();
1668 // C++0x [temp.param]p9:
1669 // A default template-argument may be specified for any kind of
1670 // template-parameter that is not a template parameter pack.
1671 if (IsParameterPack
&& !Default
.isInvalid()) {
1672 Diag(EqualLoc
, diag::err_template_param_pack_default_arg
);
1673 Default
= ParsedTemplateArgument();
1676 if (!Default
.isInvalid()) {
1677 // Check only that we have a template template argument. We don't want to
1678 // try to check well-formedness now, because our template template parameter
1679 // might have dependent types in its template parameters, which we wouldn't
1680 // be able to match now.
1682 // If none of the template template parameter's template arguments mention
1683 // other template parameters, we could actually perform more checking here.
1684 // However, it isn't worth doing.
1685 TemplateArgumentLoc DefaultArg
= translateTemplateArgument(*this, Default
);
1686 if (DefaultArg
.getArgument().getAsTemplate().isNull()) {
1687 Diag(DefaultArg
.getLocation(), diag::err_template_arg_not_valid_template
)
1688 << DefaultArg
.getSourceRange();
1692 // Check for unexpanded parameter packs.
1693 if (DiagnoseUnexpandedParameterPack(DefaultArg
.getLocation(),
1694 DefaultArg
.getArgument().getAsTemplate(),
1695 UPPC_DefaultArgument
))
1698 Param
->setDefaultArgument(Context
, DefaultArg
);
1705 class ConstraintRefersToContainingTemplateChecker
1706 : public TreeTransform
<ConstraintRefersToContainingTemplateChecker
> {
1707 bool Result
= false;
1708 const FunctionDecl
*Friend
= nullptr;
1709 unsigned TemplateDepth
= 0;
1711 // Check a record-decl that we've seen to see if it is a lexical parent of the
1712 // Friend, likely because it was referred to without its template arguments.
1713 void CheckIfContainingRecord(const CXXRecordDecl
*CheckingRD
) {
1714 CheckingRD
= CheckingRD
->getMostRecentDecl();
1715 if (!CheckingRD
->isTemplated())
1718 for (const DeclContext
*DC
= Friend
->getLexicalDeclContext();
1719 DC
&& !DC
->isFileContext(); DC
= DC
->getParent())
1720 if (const auto *RD
= dyn_cast
<CXXRecordDecl
>(DC
))
1721 if (CheckingRD
== RD
->getMostRecentDecl())
1725 void CheckNonTypeTemplateParmDecl(NonTypeTemplateParmDecl
*D
) {
1726 assert(D
->getDepth() <= TemplateDepth
&&
1727 "Nothing should reference a value below the actual template depth, "
1728 "depth is likely wrong");
1729 if (D
->getDepth() != TemplateDepth
)
1732 // Necessary because the type of the NTTP might be what refers to the parent
1734 TransformType(D
->getType());
1738 using inherited
= TreeTransform
<ConstraintRefersToContainingTemplateChecker
>;
1740 ConstraintRefersToContainingTemplateChecker(Sema
&SemaRef
,
1741 const FunctionDecl
*Friend
,
1742 unsigned TemplateDepth
)
1743 : inherited(SemaRef
), Friend(Friend
), TemplateDepth(TemplateDepth
) {}
1744 bool getResult() const { return Result
; }
1746 // This should be the only template parm type that we have to deal with.
1747 // SubstTempalteTypeParmPack, SubstNonTypeTemplateParmPack, and
1748 // FunctionParmPackExpr are all partially substituted, which cannot happen
1749 // with concepts at this point in translation.
1750 using inherited::TransformTemplateTypeParmType
;
1751 QualType
TransformTemplateTypeParmType(TypeLocBuilder
&TLB
,
1752 TemplateTypeParmTypeLoc TL
, bool) {
1753 assert(TL
.getDecl()->getDepth() <= TemplateDepth
&&
1754 "Nothing should reference a value below the actual template depth, "
1755 "depth is likely wrong");
1756 if (TL
.getDecl()->getDepth() != TemplateDepth
)
1758 return inherited::TransformTemplateTypeParmType(
1760 /*SuppressObjCLifetime=*/false);
1763 Decl
*TransformDecl(SourceLocation Loc
, Decl
*D
) {
1766 // FIXME : This is possibly an incomplete list, but it is unclear what other
1767 // Decl kinds could be used to refer to the template parameters. This is a
1768 // best guess so far based on examples currently available, but the
1769 // unreachable should catch future instances/cases.
1770 if (auto *TD
= dyn_cast
<TypedefNameDecl
>(D
))
1771 TransformType(TD
->getUnderlyingType());
1772 else if (auto *NTTPD
= dyn_cast
<NonTypeTemplateParmDecl
>(D
))
1773 CheckNonTypeTemplateParmDecl(NTTPD
);
1774 else if (auto *VD
= dyn_cast
<ValueDecl
>(D
))
1775 TransformType(VD
->getType());
1776 else if (auto *TD
= dyn_cast
<TemplateDecl
>(D
))
1777 TransformTemplateParameterList(TD
->getTemplateParameters());
1778 else if (auto *RD
= dyn_cast
<CXXRecordDecl
>(D
))
1779 CheckIfContainingRecord(RD
);
1780 else if (isa
<NamedDecl
>(D
)) {
1781 // No direct types to visit here I believe.
1783 llvm_unreachable("Don't know how to handle this declaration type yet");
1789 bool Sema::ConstraintExpressionDependsOnEnclosingTemplate(
1790 const FunctionDecl
*Friend
, unsigned TemplateDepth
,
1791 const Expr
*Constraint
) {
1792 assert(Friend
->getFriendObjectKind() && "Only works on a friend");
1793 ConstraintRefersToContainingTemplateChecker
Checker(*this, Friend
,
1795 Checker
.TransformExpr(const_cast<Expr
*>(Constraint
));
1796 return Checker
.getResult();
1799 /// ActOnTemplateParameterList - Builds a TemplateParameterList, optionally
1800 /// constrained by RequiresClause, that contains the template parameters in
1802 TemplateParameterList
*
1803 Sema::ActOnTemplateParameterList(unsigned Depth
,
1804 SourceLocation ExportLoc
,
1805 SourceLocation TemplateLoc
,
1806 SourceLocation LAngleLoc
,
1807 ArrayRef
<NamedDecl
*> Params
,
1808 SourceLocation RAngleLoc
,
1809 Expr
*RequiresClause
) {
1810 if (ExportLoc
.isValid())
1811 Diag(ExportLoc
, diag::warn_template_export_unsupported
);
1813 for (NamedDecl
*P
: Params
)
1814 warnOnReservedIdentifier(P
);
1816 return TemplateParameterList::Create(
1817 Context
, TemplateLoc
, LAngleLoc
,
1818 llvm::ArrayRef(Params
.data(), Params
.size()), RAngleLoc
, RequiresClause
);
1821 static void SetNestedNameSpecifier(Sema
&S
, TagDecl
*T
,
1822 const CXXScopeSpec
&SS
) {
1824 T
->setQualifierInfo(SS
.getWithLocInContext(S
.Context
));
1827 // Returns the template parameter list with all default template argument
1829 static TemplateParameterList
*GetTemplateParameterList(TemplateDecl
*TD
) {
1830 // Make sure we get the template parameter list from the most
1831 // recent declaration, since that is the only one that is guaranteed to
1832 // have all the default template argument information.
1833 return cast
<TemplateDecl
>(TD
->getMostRecentDecl())->getTemplateParameters();
1836 DeclResult
Sema::CheckClassTemplate(
1837 Scope
*S
, unsigned TagSpec
, TagUseKind TUK
, SourceLocation KWLoc
,
1838 CXXScopeSpec
&SS
, IdentifierInfo
*Name
, SourceLocation NameLoc
,
1839 const ParsedAttributesView
&Attr
, TemplateParameterList
*TemplateParams
,
1840 AccessSpecifier AS
, SourceLocation ModulePrivateLoc
,
1841 SourceLocation FriendLoc
, unsigned NumOuterTemplateParamLists
,
1842 TemplateParameterList
**OuterTemplateParamLists
, SkipBodyInfo
*SkipBody
) {
1843 assert(TemplateParams
&& TemplateParams
->size() > 0 &&
1844 "No template parameters");
1845 assert(TUK
!= TUK_Reference
&& "Can only declare or define class templates");
1846 bool Invalid
= false;
1848 // Check that we can declare a template here.
1849 if (CheckTemplateDeclScope(S
, TemplateParams
))
1852 TagTypeKind Kind
= TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec
);
1853 assert(Kind
!= TagTypeKind::Enum
&&
1854 "can't build template of enumerated type");
1856 // There is no such thing as an unnamed class template.
1858 Diag(KWLoc
, diag::err_template_unnamed_class
);
1862 // Find any previous declaration with this name. For a friend with no
1863 // scope explicitly specified, we only look for tag declarations (per
1864 // C++11 [basic.lookup.elab]p2).
1865 DeclContext
*SemanticContext
;
1866 LookupResult
Previous(*this, Name
, NameLoc
,
1867 (SS
.isEmpty() && TUK
== TUK_Friend
)
1868 ? LookupTagName
: LookupOrdinaryName
,
1869 forRedeclarationInCurContext());
1870 if (SS
.isNotEmpty() && !SS
.isInvalid()) {
1871 SemanticContext
= computeDeclContext(SS
, true);
1872 if (!SemanticContext
) {
1873 // FIXME: Horrible, horrible hack! We can't currently represent this
1874 // in the AST, and historically we have just ignored such friend
1875 // class templates, so don't complain here.
1876 Diag(NameLoc
, TUK
== TUK_Friend
1877 ? diag::warn_template_qualified_friend_ignored
1878 : diag::err_template_qualified_declarator_no_match
)
1879 << SS
.getScopeRep() << SS
.getRange();
1880 return TUK
!= TUK_Friend
;
1883 if (RequireCompleteDeclContext(SS
, SemanticContext
))
1886 // If we're adding a template to a dependent context, we may need to
1887 // rebuilding some of the types used within the template parameter list,
1888 // now that we know what the current instantiation is.
1889 if (SemanticContext
->isDependentContext()) {
1890 ContextRAII
SavedContext(*this, SemanticContext
);
1891 if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams
))
1893 } else if (TUK
!= TUK_Friend
&& TUK
!= TUK_Reference
)
1894 diagnoseQualifiedDeclaration(SS
, SemanticContext
, Name
, NameLoc
, false);
1896 LookupQualifiedName(Previous
, SemanticContext
);
1898 SemanticContext
= CurContext
;
1900 // C++14 [class.mem]p14:
1901 // If T is the name of a class, then each of the following shall have a
1902 // name different from T:
1903 // -- every member template of class T
1904 if (TUK
!= TUK_Friend
&&
1905 DiagnoseClassNameShadow(SemanticContext
,
1906 DeclarationNameInfo(Name
, NameLoc
)))
1909 LookupName(Previous
, S
);
1912 if (Previous
.isAmbiguous())
1915 NamedDecl
*PrevDecl
= nullptr;
1916 if (Previous
.begin() != Previous
.end())
1917 PrevDecl
= (*Previous
.begin())->getUnderlyingDecl();
1919 if (PrevDecl
&& PrevDecl
->isTemplateParameter()) {
1920 // Maybe we will complain about the shadowed template parameter.
1921 DiagnoseTemplateParameterShadow(NameLoc
, PrevDecl
);
1922 // Just pretend that we didn't see the previous declaration.
1926 // If there is a previous declaration with the same name, check
1927 // whether this is a valid redeclaration.
1928 ClassTemplateDecl
*PrevClassTemplate
=
1929 dyn_cast_or_null
<ClassTemplateDecl
>(PrevDecl
);
1931 // We may have found the injected-class-name of a class template,
1932 // class template partial specialization, or class template specialization.
1933 // In these cases, grab the template that is being defined or specialized.
1934 if (!PrevClassTemplate
&& PrevDecl
&& isa
<CXXRecordDecl
>(PrevDecl
) &&
1935 cast
<CXXRecordDecl
>(PrevDecl
)->isInjectedClassName()) {
1936 PrevDecl
= cast
<CXXRecordDecl
>(PrevDecl
->getDeclContext());
1938 = cast
<CXXRecordDecl
>(PrevDecl
)->getDescribedClassTemplate();
1939 if (!PrevClassTemplate
&& isa
<ClassTemplateSpecializationDecl
>(PrevDecl
)) {
1941 = cast
<ClassTemplateSpecializationDecl
>(PrevDecl
)
1942 ->getSpecializedTemplate();
1946 if (TUK
== TUK_Friend
) {
1947 // C++ [namespace.memdef]p3:
1948 // [...] When looking for a prior declaration of a class or a function
1949 // declared as a friend, and when the name of the friend class or
1950 // function is neither a qualified name nor a template-id, scopes outside
1951 // the innermost enclosing namespace scope are not considered.
1953 DeclContext
*OutermostContext
= CurContext
;
1954 while (!OutermostContext
->isFileContext())
1955 OutermostContext
= OutermostContext
->getLookupParent();
1958 (OutermostContext
->Equals(PrevDecl
->getDeclContext()) ||
1959 OutermostContext
->Encloses(PrevDecl
->getDeclContext()))) {
1960 SemanticContext
= PrevDecl
->getDeclContext();
1962 // Declarations in outer scopes don't matter. However, the outermost
1963 // context we computed is the semantic context for our new
1965 PrevDecl
= PrevClassTemplate
= nullptr;
1966 SemanticContext
= OutermostContext
;
1968 // Check that the chosen semantic context doesn't already contain a
1969 // declaration of this name as a non-tag type.
1970 Previous
.clear(LookupOrdinaryName
);
1971 DeclContext
*LookupContext
= SemanticContext
;
1972 while (LookupContext
->isTransparentContext())
1973 LookupContext
= LookupContext
->getLookupParent();
1974 LookupQualifiedName(Previous
, LookupContext
);
1976 if (Previous
.isAmbiguous())
1979 if (Previous
.begin() != Previous
.end())
1980 PrevDecl
= (*Previous
.begin())->getUnderlyingDecl();
1983 } else if (PrevDecl
&&
1984 !isDeclInScope(Previous
.getRepresentativeDecl(), SemanticContext
,
1986 PrevDecl
= PrevClassTemplate
= nullptr;
1988 if (auto *Shadow
= dyn_cast_or_null
<UsingShadowDecl
>(
1989 PrevDecl
? Previous
.getRepresentativeDecl() : nullptr)) {
1991 !(PrevClassTemplate
&&
1992 PrevClassTemplate
->getDeclContext()->getRedeclContext()->Equals(
1993 SemanticContext
->getRedeclContext()))) {
1994 Diag(KWLoc
, diag::err_using_decl_conflict_reverse
);
1995 Diag(Shadow
->getTargetDecl()->getLocation(),
1996 diag::note_using_decl_target
);
1997 Diag(Shadow
->getIntroducer()->getLocation(), diag::note_using_decl
) << 0;
1998 // Recover by ignoring the old declaration.
1999 PrevDecl
= PrevClassTemplate
= nullptr;
2003 if (PrevClassTemplate
) {
2004 // Ensure that the template parameter lists are compatible. Skip this check
2005 // for a friend in a dependent context: the template parameter list itself
2006 // could be dependent.
2007 if (!(TUK
== TUK_Friend
&& CurContext
->isDependentContext()) &&
2008 !TemplateParameterListsAreEqual(
2009 TemplateCompareNewDeclInfo(SemanticContext
? SemanticContext
2012 TemplateParams
, PrevClassTemplate
,
2013 PrevClassTemplate
->getTemplateParameters(), /*Complain=*/true,
2017 // C++ [temp.class]p4:
2018 // In a redeclaration, partial specialization, explicit
2019 // specialization or explicit instantiation of a class template,
2020 // the class-key shall agree in kind with the original class
2021 // template declaration (7.1.5.3).
2022 RecordDecl
*PrevRecordDecl
= PrevClassTemplate
->getTemplatedDecl();
2023 if (!isAcceptableTagRedeclaration(PrevRecordDecl
, Kind
,
2024 TUK
== TUK_Definition
, KWLoc
, Name
)) {
2025 Diag(KWLoc
, diag::err_use_with_wrong_tag
)
2027 << FixItHint::CreateReplacement(KWLoc
, PrevRecordDecl
->getKindName());
2028 Diag(PrevRecordDecl
->getLocation(), diag::note_previous_use
);
2029 Kind
= PrevRecordDecl
->getTagKind();
2032 // Check for redefinition of this class template.
2033 if (TUK
== TUK_Definition
) {
2034 if (TagDecl
*Def
= PrevRecordDecl
->getDefinition()) {
2035 // If we have a prior definition that is not visible, treat this as
2036 // simply making that previous definition visible.
2037 NamedDecl
*Hidden
= nullptr;
2038 if (SkipBody
&& !hasVisibleDefinition(Def
, &Hidden
)) {
2039 SkipBody
->ShouldSkip
= true;
2040 SkipBody
->Previous
= Def
;
2041 auto *Tmpl
= cast
<CXXRecordDecl
>(Hidden
)->getDescribedClassTemplate();
2042 assert(Tmpl
&& "original definition of a class template is not a "
2044 makeMergedDefinitionVisible(Hidden
);
2045 makeMergedDefinitionVisible(Tmpl
);
2047 Diag(NameLoc
, diag::err_redefinition
) << Name
;
2048 Diag(Def
->getLocation(), diag::note_previous_definition
);
2049 // FIXME: Would it make sense to try to "forget" the previous
2050 // definition, as part of error recovery?
2055 } else if (PrevDecl
) {
2057 // A class template shall not have the same name as any other
2058 // template, class, function, object, enumeration, enumerator,
2059 // namespace, or type in the same scope (3.3), except as specified
2061 Diag(NameLoc
, diag::err_redefinition_different_kind
) << Name
;
2062 Diag(PrevDecl
->getLocation(), diag::note_previous_definition
);
2066 // Check the template parameter list of this declaration, possibly
2067 // merging in the template parameter list from the previous class
2068 // template declaration. Skip this check for a friend in a dependent
2069 // context, because the template parameter list might be dependent.
2070 if (!(TUK
== TUK_Friend
&& CurContext
->isDependentContext()) &&
2071 CheckTemplateParameterList(
2073 PrevClassTemplate
? GetTemplateParameterList(PrevClassTemplate
)
2075 (SS
.isSet() && SemanticContext
&& SemanticContext
->isRecord() &&
2076 SemanticContext
->isDependentContext())
2077 ? TPC_ClassTemplateMember
2078 : TUK
== TUK_Friend
? TPC_FriendClassTemplate
2079 : TPC_ClassTemplate
,
2084 // If the name of the template was qualified, we must be defining the
2085 // template out-of-line.
2086 if (!SS
.isInvalid() && !Invalid
&& !PrevClassTemplate
) {
2087 Diag(NameLoc
, TUK
== TUK_Friend
? diag::err_friend_decl_does_not_match
2088 : diag::err_member_decl_does_not_match
)
2089 << Name
<< SemanticContext
<< /*IsDefinition*/true << SS
.getRange();
2094 // If this is a templated friend in a dependent context we should not put it
2095 // on the redecl chain. In some cases, the templated friend can be the most
2096 // recent declaration tricking the template instantiator to make substitutions
2098 // FIXME: Figure out how to combine with shouldLinkDependentDeclWithPrevious
2099 bool ShouldAddRedecl
2100 = !(TUK
== TUK_Friend
&& CurContext
->isDependentContext());
2102 CXXRecordDecl
*NewClass
=
2103 CXXRecordDecl::Create(Context
, Kind
, SemanticContext
, KWLoc
, NameLoc
, Name
,
2104 PrevClassTemplate
&& ShouldAddRedecl
?
2105 PrevClassTemplate
->getTemplatedDecl() : nullptr,
2106 /*DelayTypeCreation=*/true);
2107 SetNestedNameSpecifier(*this, NewClass
, SS
);
2108 if (NumOuterTemplateParamLists
> 0)
2109 NewClass
->setTemplateParameterListsInfo(
2111 llvm::ArrayRef(OuterTemplateParamLists
, NumOuterTemplateParamLists
));
2113 // Add alignment attributes if necessary; these attributes are checked when
2114 // the ASTContext lays out the structure.
2115 if (TUK
== TUK_Definition
&& (!SkipBody
|| !SkipBody
->ShouldSkip
)) {
2116 AddAlignmentAttributesForRecord(NewClass
);
2117 AddMsStructLayoutForRecord(NewClass
);
2120 ClassTemplateDecl
*NewTemplate
2121 = ClassTemplateDecl::Create(Context
, SemanticContext
, NameLoc
,
2122 DeclarationName(Name
), TemplateParams
,
2125 if (ShouldAddRedecl
)
2126 NewTemplate
->setPreviousDecl(PrevClassTemplate
);
2128 NewClass
->setDescribedClassTemplate(NewTemplate
);
2130 if (ModulePrivateLoc
.isValid())
2131 NewTemplate
->setModulePrivate();
2133 // Build the type for the class template declaration now.
2134 QualType T
= NewTemplate
->getInjectedClassNameSpecialization();
2135 T
= Context
.getInjectedClassNameType(NewClass
, T
);
2136 assert(T
->isDependentType() && "Class template type is not dependent?");
2139 // If we are providing an explicit specialization of a member that is a
2140 // class template, make a note of that.
2141 if (PrevClassTemplate
&&
2142 PrevClassTemplate
->getInstantiatedFromMemberTemplate())
2143 PrevClassTemplate
->setMemberSpecialization();
2145 // Set the access specifier.
2146 if (!Invalid
&& TUK
!= TUK_Friend
&& NewTemplate
->getDeclContext()->isRecord())
2147 SetMemberAccessSpecifier(NewTemplate
, PrevClassTemplate
, AS
);
2149 // Set the lexical context of these templates
2150 NewClass
->setLexicalDeclContext(CurContext
);
2151 NewTemplate
->setLexicalDeclContext(CurContext
);
2153 if (TUK
== TUK_Definition
&& (!SkipBody
|| !SkipBody
->ShouldSkip
))
2154 NewClass
->startDefinition();
2156 ProcessDeclAttributeList(S
, NewClass
, Attr
);
2158 if (PrevClassTemplate
)
2159 mergeDeclAttributes(NewClass
, PrevClassTemplate
->getTemplatedDecl());
2161 AddPushedVisibilityAttribute(NewClass
);
2162 inferGslOwnerPointerAttribute(NewClass
);
2164 if (TUK
!= TUK_Friend
) {
2165 // Per C++ [basic.scope.temp]p2, skip the template parameter scopes.
2167 while ((Outer
->getFlags() & Scope::TemplateParamScope
) != 0)
2168 Outer
= Outer
->getParent();
2169 PushOnScopeChains(NewTemplate
, Outer
);
2171 if (PrevClassTemplate
&& PrevClassTemplate
->getAccess() != AS_none
) {
2172 NewTemplate
->setAccess(PrevClassTemplate
->getAccess());
2173 NewClass
->setAccess(PrevClassTemplate
->getAccess());
2176 NewTemplate
->setObjectOfFriendDecl();
2178 // Friend templates are visible in fairly strange ways.
2179 if (!CurContext
->isDependentContext()) {
2180 DeclContext
*DC
= SemanticContext
->getRedeclContext();
2181 DC
->makeDeclVisibleInContext(NewTemplate
);
2182 if (Scope
*EnclosingScope
= getScopeForDeclContext(S
, DC
))
2183 PushOnScopeChains(NewTemplate
, EnclosingScope
,
2184 /* AddToContext = */ false);
2187 FriendDecl
*Friend
= FriendDecl::Create(
2188 Context
, CurContext
, NewClass
->getLocation(), NewTemplate
, FriendLoc
);
2189 Friend
->setAccess(AS_public
);
2190 CurContext
->addDecl(Friend
);
2193 if (PrevClassTemplate
)
2194 CheckRedeclarationInModule(NewTemplate
, PrevClassTemplate
);
2197 NewTemplate
->setInvalidDecl();
2198 NewClass
->setInvalidDecl();
2201 ActOnDocumentableDecl(NewTemplate
);
2203 if (SkipBody
&& SkipBody
->ShouldSkip
)
2204 return SkipBody
->Previous
;
2210 /// Tree transform to "extract" a transformed type from a class template's
2211 /// constructor to a deduction guide.
2212 class ExtractTypeForDeductionGuide
2213 : public TreeTransform
<ExtractTypeForDeductionGuide
> {
2214 llvm::SmallVectorImpl
<TypedefNameDecl
*> &MaterializedTypedefs
;
2217 typedef TreeTransform
<ExtractTypeForDeductionGuide
> Base
;
2218 ExtractTypeForDeductionGuide(
2220 llvm::SmallVectorImpl
<TypedefNameDecl
*> &MaterializedTypedefs
)
2221 : Base(SemaRef
), MaterializedTypedefs(MaterializedTypedefs
) {}
2223 TypeSourceInfo
*transform(TypeSourceInfo
*TSI
) { return TransformType(TSI
); }
2225 QualType
TransformTypedefType(TypeLocBuilder
&TLB
, TypedefTypeLoc TL
) {
2226 ASTContext
&Context
= SemaRef
.getASTContext();
2227 TypedefNameDecl
*OrigDecl
= TL
.getTypedefNameDecl();
2228 TypedefNameDecl
*Decl
= OrigDecl
;
2229 // Transform the underlying type of the typedef and clone the Decl only if
2230 // the typedef has a dependent context.
2231 if (OrigDecl
->getDeclContext()->isDependentContext()) {
2232 TypeLocBuilder InnerTLB
;
2233 QualType Transformed
=
2234 TransformType(InnerTLB
, OrigDecl
->getTypeSourceInfo()->getTypeLoc());
2235 TypeSourceInfo
*TSI
= InnerTLB
.getTypeSourceInfo(Context
, Transformed
);
2236 if (isa
<TypeAliasDecl
>(OrigDecl
))
2237 Decl
= TypeAliasDecl::Create(
2238 Context
, Context
.getTranslationUnitDecl(), OrigDecl
->getBeginLoc(),
2239 OrigDecl
->getLocation(), OrigDecl
->getIdentifier(), TSI
);
2241 assert(isa
<TypedefDecl
>(OrigDecl
) && "Not a Type alias or typedef");
2242 Decl
= TypedefDecl::Create(
2243 Context
, Context
.getTranslationUnitDecl(), OrigDecl
->getBeginLoc(),
2244 OrigDecl
->getLocation(), OrigDecl
->getIdentifier(), TSI
);
2246 MaterializedTypedefs
.push_back(Decl
);
2249 QualType TDTy
= Context
.getTypedefType(Decl
);
2250 TypedefTypeLoc TypedefTL
= TLB
.push
<TypedefTypeLoc
>(TDTy
);
2251 TypedefTL
.setNameLoc(TL
.getNameLoc());
2257 /// Transform to convert portions of a constructor declaration into the
2258 /// corresponding deduction guide, per C++1z [over.match.class.deduct]p1.
2259 struct ConvertConstructorToDeductionGuideTransform
{
2260 ConvertConstructorToDeductionGuideTransform(Sema
&S
,
2261 ClassTemplateDecl
*Template
)
2262 : SemaRef(S
), Template(Template
) {
2263 // If the template is nested, then we need to use the original
2264 // pattern to iterate over the constructors.
2265 ClassTemplateDecl
*Pattern
= Template
;
2266 while (Pattern
->getInstantiatedFromMemberTemplate()) {
2267 if (Pattern
->isMemberSpecialization())
2269 Pattern
= Pattern
->getInstantiatedFromMemberTemplate();
2270 NestedPattern
= Pattern
;
2274 OuterInstantiationArgs
= SemaRef
.getTemplateInstantiationArgs(Template
);
2278 ClassTemplateDecl
*Template
;
2279 ClassTemplateDecl
*NestedPattern
= nullptr;
2281 DeclContext
*DC
= Template
->getDeclContext();
2282 CXXRecordDecl
*Primary
= Template
->getTemplatedDecl();
2283 DeclarationName DeductionGuideName
=
2284 SemaRef
.Context
.DeclarationNames
.getCXXDeductionGuideName(Template
);
2286 QualType DeducedType
= SemaRef
.Context
.getTypeDeclType(Primary
);
2288 // Index adjustment to apply to convert depth-1 template parameters into
2289 // depth-0 template parameters.
2290 unsigned Depth1IndexAdjustment
= Template
->getTemplateParameters()->size();
2292 // Instantiation arguments for the outermost depth-1 templates
2293 // when the template is nested
2294 MultiLevelTemplateArgumentList OuterInstantiationArgs
;
2296 /// Transform a constructor declaration into a deduction guide.
2297 NamedDecl
*transformConstructor(FunctionTemplateDecl
*FTD
,
2298 CXXConstructorDecl
*CD
) {
2299 SmallVector
<TemplateArgument
, 16> SubstArgs
;
2301 LocalInstantiationScope
Scope(SemaRef
);
2303 // C++ [over.match.class.deduct]p1:
2304 // -- For each constructor of the class template designated by the
2305 // template-name, a function template with the following properties:
2307 // -- The template parameters are the template parameters of the class
2308 // template followed by the template parameters (including default
2309 // template arguments) of the constructor, if any.
2310 TemplateParameterList
*TemplateParams
= GetTemplateParameterList(Template
);
2312 TemplateParameterList
*InnerParams
= FTD
->getTemplateParameters();
2313 SmallVector
<NamedDecl
*, 16> AllParams
;
2314 SmallVector
<TemplateArgument
, 16> Depth1Args
;
2315 AllParams
.reserve(TemplateParams
->size() + InnerParams
->size());
2316 AllParams
.insert(AllParams
.begin(),
2317 TemplateParams
->begin(), TemplateParams
->end());
2318 SubstArgs
.reserve(InnerParams
->size());
2319 Depth1Args
.reserve(InnerParams
->size());
2321 // Later template parameters could refer to earlier ones, so build up
2322 // a list of substituted template arguments as we go.
2323 for (NamedDecl
*Param
: *InnerParams
) {
2324 MultiLevelTemplateArgumentList Args
;
2325 Args
.setKind(TemplateSubstitutionKind::Rewrite
);
2326 Args
.addOuterTemplateArguments(Depth1Args
);
2327 Args
.addOuterRetainedLevel();
2329 Args
.addOuterRetainedLevels(NestedPattern
->getTemplateDepth());
2330 NamedDecl
*NewParam
= transformTemplateParameter(Param
, Args
);
2334 // Constraints require that we substitute depth-1 arguments
2335 // to match depths when substituted for evaluation later
2336 Depth1Args
.push_back(SemaRef
.Context
.getCanonicalTemplateArgument(
2337 SemaRef
.Context
.getInjectedTemplateArg(NewParam
)));
2339 if (NestedPattern
) {
2340 TemplateDeclInstantiator
Instantiator(SemaRef
, DC
,
2341 OuterInstantiationArgs
);
2342 Instantiator
.setEvaluateConstraints(false);
2343 SemaRef
.runWithSufficientStackSpace(NewParam
->getLocation(), [&] {
2344 NewParam
= cast
<NamedDecl
>(Instantiator
.Visit(NewParam
));
2348 assert(NewParam
->getTemplateDepth() == 0 &&
2349 "Unexpected template parameter depth");
2351 AllParams
.push_back(NewParam
);
2352 SubstArgs
.push_back(SemaRef
.Context
.getCanonicalTemplateArgument(
2353 SemaRef
.Context
.getInjectedTemplateArg(NewParam
)));
2356 // Substitute new template parameters into requires-clause if present.
2357 Expr
*RequiresClause
= nullptr;
2358 if (Expr
*InnerRC
= InnerParams
->getRequiresClause()) {
2359 MultiLevelTemplateArgumentList Args
;
2360 Args
.setKind(TemplateSubstitutionKind::Rewrite
);
2361 Args
.addOuterTemplateArguments(Depth1Args
);
2362 Args
.addOuterRetainedLevel();
2364 Args
.addOuterRetainedLevels(NestedPattern
->getTemplateDepth());
2365 ExprResult E
= SemaRef
.SubstExpr(InnerRC
, Args
);
2368 RequiresClause
= E
.getAs
<Expr
>();
2371 TemplateParams
= TemplateParameterList::Create(
2372 SemaRef
.Context
, InnerParams
->getTemplateLoc(),
2373 InnerParams
->getLAngleLoc(), AllParams
, InnerParams
->getRAngleLoc(),
2377 // If we built a new template-parameter-list, track that we need to
2378 // substitute references to the old parameters into references to the
2380 MultiLevelTemplateArgumentList Args
;
2381 Args
.setKind(TemplateSubstitutionKind::Rewrite
);
2383 Args
.addOuterTemplateArguments(SubstArgs
);
2384 Args
.addOuterRetainedLevel();
2388 Args
.addOuterRetainedLevels(NestedPattern
->getTemplateDepth());
2390 FunctionProtoTypeLoc FPTL
= CD
->getTypeSourceInfo()->getTypeLoc()
2391 .getAsAdjusted
<FunctionProtoTypeLoc
>();
2392 assert(FPTL
&& "no prototype for constructor declaration");
2394 // Transform the type of the function, adjusting the return type and
2395 // replacing references to the old parameters with references to the
2398 SmallVector
<ParmVarDecl
*, 8> Params
;
2399 SmallVector
<TypedefNameDecl
*, 4> MaterializedTypedefs
;
2400 QualType NewType
= transformFunctionProtoType(TLB
, FPTL
, Params
, Args
,
2401 MaterializedTypedefs
);
2402 if (NewType
.isNull())
2404 TypeSourceInfo
*NewTInfo
= TLB
.getTypeSourceInfo(SemaRef
.Context
, NewType
);
2406 return buildDeductionGuide(TemplateParams
, CD
, CD
->getExplicitSpecifier(),
2407 NewTInfo
, CD
->getBeginLoc(), CD
->getLocation(),
2408 CD
->getEndLoc(), MaterializedTypedefs
);
2411 /// Build a deduction guide with the specified parameter types.
2412 NamedDecl
*buildSimpleDeductionGuide(MutableArrayRef
<QualType
> ParamTypes
) {
2413 SourceLocation Loc
= Template
->getLocation();
2415 // Build the requested type.
2416 FunctionProtoType::ExtProtoInfo EPI
;
2417 EPI
.HasTrailingReturn
= true;
2418 QualType Result
= SemaRef
.BuildFunctionType(DeducedType
, ParamTypes
, Loc
,
2419 DeductionGuideName
, EPI
);
2420 TypeSourceInfo
*TSI
= SemaRef
.Context
.getTrivialTypeSourceInfo(Result
, Loc
);
2422 FunctionProtoTypeLoc FPTL
=
2423 TSI
->getTypeLoc().castAs
<FunctionProtoTypeLoc
>();
2425 // Build the parameters, needed during deduction / substitution.
2426 SmallVector
<ParmVarDecl
*, 4> Params
;
2427 for (auto T
: ParamTypes
) {
2428 ParmVarDecl
*NewParam
= ParmVarDecl::Create(
2429 SemaRef
.Context
, DC
, Loc
, Loc
, nullptr, T
,
2430 SemaRef
.Context
.getTrivialTypeSourceInfo(T
, Loc
), SC_None
, nullptr);
2431 NewParam
->setScopeInfo(0, Params
.size());
2432 FPTL
.setParam(Params
.size(), NewParam
);
2433 Params
.push_back(NewParam
);
2436 return buildDeductionGuide(GetTemplateParameterList(Template
), nullptr,
2437 ExplicitSpecifier(), TSI
, Loc
, Loc
, Loc
);
2441 /// Transform a constructor template parameter into a deduction guide template
2442 /// parameter, rebuilding any internal references to earlier parameters and
2443 /// renumbering as we go.
2444 NamedDecl
*transformTemplateParameter(NamedDecl
*TemplateParam
,
2445 MultiLevelTemplateArgumentList
&Args
) {
2446 if (auto *TTP
= dyn_cast
<TemplateTypeParmDecl
>(TemplateParam
)) {
2447 // TemplateTypeParmDecl's index cannot be changed after creation, so
2448 // substitute it directly.
2449 auto *NewTTP
= TemplateTypeParmDecl::Create(
2450 SemaRef
.Context
, DC
, TTP
->getBeginLoc(), TTP
->getLocation(),
2451 TTP
->getDepth() - 1, Depth1IndexAdjustment
+ TTP
->getIndex(),
2452 TTP
->getIdentifier(), TTP
->wasDeclaredWithTypename(),
2453 TTP
->isParameterPack(), TTP
->hasTypeConstraint(),
2454 TTP
->isExpandedParameterPack()
2455 ? std::optional
<unsigned>(TTP
->getNumExpansionParameters())
2457 if (const auto *TC
= TTP
->getTypeConstraint())
2458 SemaRef
.SubstTypeConstraint(NewTTP
, TC
, Args
,
2459 /*EvaluateConstraint*/ true);
2460 if (TTP
->hasDefaultArgument()) {
2461 TypeSourceInfo
*InstantiatedDefaultArg
=
2462 SemaRef
.SubstType(TTP
->getDefaultArgumentInfo(), Args
,
2463 TTP
->getDefaultArgumentLoc(), TTP
->getDeclName());
2464 if (InstantiatedDefaultArg
)
2465 NewTTP
->setDefaultArgument(InstantiatedDefaultArg
);
2467 SemaRef
.CurrentInstantiationScope
->InstantiatedLocal(TemplateParam
,
2472 if (auto *TTP
= dyn_cast
<TemplateTemplateParmDecl
>(TemplateParam
))
2473 return transformTemplateParameterImpl(TTP
, Args
);
2475 return transformTemplateParameterImpl(
2476 cast
<NonTypeTemplateParmDecl
>(TemplateParam
), Args
);
2478 template<typename TemplateParmDecl
>
2480 transformTemplateParameterImpl(TemplateParmDecl
*OldParam
,
2481 MultiLevelTemplateArgumentList
&Args
) {
2482 // Ask the template instantiator to do the heavy lifting for us, then adjust
2483 // the index of the parameter once it's done.
2485 cast
<TemplateParmDecl
>(SemaRef
.SubstDecl(OldParam
, DC
, Args
));
2486 assert(NewParam
->getDepth() == OldParam
->getDepth() - 1 &&
2487 "unexpected template param depth");
2488 NewParam
->setPosition(NewParam
->getPosition() + Depth1IndexAdjustment
);
2492 QualType
transformFunctionProtoType(
2493 TypeLocBuilder
&TLB
, FunctionProtoTypeLoc TL
,
2494 SmallVectorImpl
<ParmVarDecl
*> &Params
,
2495 MultiLevelTemplateArgumentList
&Args
,
2496 SmallVectorImpl
<TypedefNameDecl
*> &MaterializedTypedefs
) {
2497 SmallVector
<QualType
, 4> ParamTypes
;
2498 const FunctionProtoType
*T
= TL
.getTypePtr();
2500 // -- The types of the function parameters are those of the constructor.
2501 for (auto *OldParam
: TL
.getParams()) {
2502 ParmVarDecl
*NewParam
=
2503 transformFunctionTypeParam(OldParam
, Args
, MaterializedTypedefs
);
2504 if (NestedPattern
&& NewParam
)
2505 NewParam
= transformFunctionTypeParam(NewParam
, OuterInstantiationArgs
,
2506 MaterializedTypedefs
);
2509 ParamTypes
.push_back(NewParam
->getType());
2510 Params
.push_back(NewParam
);
2513 // -- The return type is the class template specialization designated by
2514 // the template-name and template arguments corresponding to the
2515 // template parameters obtained from the class template.
2517 // We use the injected-class-name type of the primary template instead.
2518 // This has the convenient property that it is different from any type that
2519 // the user can write in a deduction-guide (because they cannot enter the
2520 // context of the template), so implicit deduction guides can never collide
2521 // with explicit ones.
2522 QualType ReturnType
= DeducedType
;
2523 TLB
.pushTypeSpec(ReturnType
).setNameLoc(Primary
->getLocation());
2525 // Resolving a wording defect, we also inherit the variadicness of the
2527 FunctionProtoType::ExtProtoInfo EPI
;
2528 EPI
.Variadic
= T
->isVariadic();
2529 EPI
.HasTrailingReturn
= true;
2531 QualType Result
= SemaRef
.BuildFunctionType(
2532 ReturnType
, ParamTypes
, TL
.getBeginLoc(), DeductionGuideName
, EPI
);
2533 if (Result
.isNull())
2536 FunctionProtoTypeLoc NewTL
= TLB
.push
<FunctionProtoTypeLoc
>(Result
);
2537 NewTL
.setLocalRangeBegin(TL
.getLocalRangeBegin());
2538 NewTL
.setLParenLoc(TL
.getLParenLoc());
2539 NewTL
.setRParenLoc(TL
.getRParenLoc());
2540 NewTL
.setExceptionSpecRange(SourceRange());
2541 NewTL
.setLocalRangeEnd(TL
.getLocalRangeEnd());
2542 for (unsigned I
= 0, E
= NewTL
.getNumParams(); I
!= E
; ++I
)
2543 NewTL
.setParam(I
, Params
[I
]);
2548 ParmVarDecl
*transformFunctionTypeParam(
2549 ParmVarDecl
*OldParam
, MultiLevelTemplateArgumentList
&Args
,
2550 llvm::SmallVectorImpl
<TypedefNameDecl
*> &MaterializedTypedefs
) {
2551 TypeSourceInfo
*OldDI
= OldParam
->getTypeSourceInfo();
2552 TypeSourceInfo
*NewDI
;
2553 if (auto PackTL
= OldDI
->getTypeLoc().getAs
<PackExpansionTypeLoc
>()) {
2554 // Expand out the one and only element in each inner pack.
2555 Sema::ArgumentPackSubstitutionIndexRAII
SubstIndex(SemaRef
, 0);
2557 SemaRef
.SubstType(PackTL
.getPatternLoc(), Args
,
2558 OldParam
->getLocation(), OldParam
->getDeclName());
2559 if (!NewDI
) return nullptr;
2561 SemaRef
.CheckPackExpansion(NewDI
, PackTL
.getEllipsisLoc(),
2562 PackTL
.getTypePtr()->getNumExpansions());
2564 NewDI
= SemaRef
.SubstType(OldDI
, Args
, OldParam
->getLocation(),
2565 OldParam
->getDeclName());
2569 // Extract the type. This (for instance) replaces references to typedef
2570 // members of the current instantiations with the definitions of those
2571 // typedefs, avoiding triggering instantiation of the deduced type during
2573 NewDI
= ExtractTypeForDeductionGuide(SemaRef
, MaterializedTypedefs
)
2576 // Resolving a wording defect, we also inherit default arguments from the
2578 ExprResult NewDefArg
;
2579 if (OldParam
->hasDefaultArg()) {
2580 // We don't care what the value is (we won't use it); just create a
2581 // placeholder to indicate there is a default argument.
2582 QualType ParamTy
= NewDI
->getType();
2583 NewDefArg
= new (SemaRef
.Context
)
2584 OpaqueValueExpr(OldParam
->getDefaultArg()->getBeginLoc(),
2585 ParamTy
.getNonLValueExprType(SemaRef
.Context
),
2586 ParamTy
->isLValueReferenceType() ? VK_LValue
2587 : ParamTy
->isRValueReferenceType() ? VK_XValue
2591 ParmVarDecl
*NewParam
= ParmVarDecl::Create(SemaRef
.Context
, DC
,
2592 OldParam
->getInnerLocStart(),
2593 OldParam
->getLocation(),
2594 OldParam
->getIdentifier(),
2597 OldParam
->getStorageClass(),
2599 NewParam
->setScopeInfo(OldParam
->getFunctionScopeDepth(),
2600 OldParam
->getFunctionScopeIndex());
2601 SemaRef
.CurrentInstantiationScope
->InstantiatedLocal(OldParam
, NewParam
);
2605 FunctionTemplateDecl
*buildDeductionGuide(
2606 TemplateParameterList
*TemplateParams
, CXXConstructorDecl
*Ctor
,
2607 ExplicitSpecifier ES
, TypeSourceInfo
*TInfo
, SourceLocation LocStart
,
2608 SourceLocation Loc
, SourceLocation LocEnd
,
2609 llvm::ArrayRef
<TypedefNameDecl
*> MaterializedTypedefs
= {}) {
2610 DeclarationNameInfo
Name(DeductionGuideName
, Loc
);
2611 ArrayRef
<ParmVarDecl
*> Params
=
2612 TInfo
->getTypeLoc().castAs
<FunctionProtoTypeLoc
>().getParams();
2614 // Build the implicit deduction guide template.
2616 CXXDeductionGuideDecl::Create(SemaRef
.Context
, DC
, LocStart
, ES
, Name
,
2617 TInfo
->getType(), TInfo
, LocEnd
, Ctor
);
2618 Guide
->setImplicit();
2619 Guide
->setParams(Params
);
2621 for (auto *Param
: Params
)
2622 Param
->setDeclContext(Guide
);
2623 for (auto *TD
: MaterializedTypedefs
)
2624 TD
->setDeclContext(Guide
);
2626 auto *GuideTemplate
= FunctionTemplateDecl::Create(
2627 SemaRef
.Context
, DC
, Loc
, DeductionGuideName
, TemplateParams
, Guide
);
2628 GuideTemplate
->setImplicit();
2629 Guide
->setDescribedFunctionTemplate(GuideTemplate
);
2631 if (isa
<CXXRecordDecl
>(DC
)) {
2632 Guide
->setAccess(AS_public
);
2633 GuideTemplate
->setAccess(AS_public
);
2636 DC
->addDecl(GuideTemplate
);
2637 return GuideTemplate
;
2642 FunctionTemplateDecl
*Sema::DeclareImplicitDeductionGuideFromInitList(
2643 TemplateDecl
*Template
, MutableArrayRef
<QualType
> ParamTypes
,
2644 SourceLocation Loc
) {
2645 if (CXXRecordDecl
*DefRecord
=
2646 cast
<CXXRecordDecl
>(Template
->getTemplatedDecl())->getDefinition()) {
2647 if (TemplateDecl
*DescribedTemplate
=
2648 DefRecord
->getDescribedClassTemplate())
2649 Template
= DescribedTemplate
;
2652 DeclContext
*DC
= Template
->getDeclContext();
2653 if (DC
->isDependentContext())
2656 ConvertConstructorToDeductionGuideTransform
Transform(
2657 *this, cast
<ClassTemplateDecl
>(Template
));
2658 if (!isCompleteType(Loc
, Transform
.DeducedType
))
2661 // In case we were expanding a pack when we attempted to declare deduction
2662 // guides, turn off pack expansion for everything we're about to do.
2663 ArgumentPackSubstitutionIndexRAII
SubstIndex(*this,
2664 /*NewSubstitutionIndex=*/-1);
2665 // Create a template instantiation record to track the "instantiation" of
2666 // constructors into deduction guides.
2667 InstantiatingTemplate
BuildingDeductionGuides(
2668 *this, Loc
, Template
,
2669 Sema::InstantiatingTemplate::BuildingDeductionGuidesTag
{});
2670 if (BuildingDeductionGuides
.isInvalid())
2673 return cast
<FunctionTemplateDecl
>(
2674 Transform
.buildSimpleDeductionGuide(ParamTypes
));
2677 void Sema::DeclareImplicitDeductionGuides(TemplateDecl
*Template
,
2678 SourceLocation Loc
) {
2679 if (CXXRecordDecl
*DefRecord
=
2680 cast
<CXXRecordDecl
>(Template
->getTemplatedDecl())->getDefinition()) {
2681 if (TemplateDecl
*DescribedTemplate
= DefRecord
->getDescribedClassTemplate())
2682 Template
= DescribedTemplate
;
2685 DeclContext
*DC
= Template
->getDeclContext();
2686 if (DC
->isDependentContext())
2689 ConvertConstructorToDeductionGuideTransform
Transform(
2690 *this, cast
<ClassTemplateDecl
>(Template
));
2691 if (!isCompleteType(Loc
, Transform
.DeducedType
))
2694 // Check whether we've already declared deduction guides for this template.
2695 // FIXME: Consider storing a flag on the template to indicate this.
2696 auto Existing
= DC
->lookup(Transform
.DeductionGuideName
);
2697 for (auto *D
: Existing
)
2698 if (D
->isImplicit())
2701 // In case we were expanding a pack when we attempted to declare deduction
2702 // guides, turn off pack expansion for everything we're about to do.
2703 ArgumentPackSubstitutionIndexRAII
SubstIndex(*this, -1);
2704 // Create a template instantiation record to track the "instantiation" of
2705 // constructors into deduction guides.
2706 InstantiatingTemplate
BuildingDeductionGuides(
2707 *this, Loc
, Template
,
2708 Sema::InstantiatingTemplate::BuildingDeductionGuidesTag
{});
2709 if (BuildingDeductionGuides
.isInvalid())
2712 // Convert declared constructors into deduction guide templates.
2713 // FIXME: Skip constructors for which deduction must necessarily fail (those
2714 // for which some class template parameter without a default argument never
2715 // appears in a deduced context).
2716 ClassTemplateDecl
*Pattern
=
2717 Transform
.NestedPattern
? Transform
.NestedPattern
: Transform
.Template
;
2718 ContextRAII
SavedContext(*this, Pattern
->getTemplatedDecl());
2719 llvm::SmallPtrSet
<NamedDecl
*, 8> ProcessedCtors
;
2720 bool AddedAny
= false;
2721 for (NamedDecl
*D
: LookupConstructors(Pattern
->getTemplatedDecl())) {
2722 D
= D
->getUnderlyingDecl();
2723 if (D
->isInvalidDecl() || D
->isImplicit())
2726 D
= cast
<NamedDecl
>(D
->getCanonicalDecl());
2728 // Within C++20 modules, we may have multiple same constructors in
2729 // multiple same RecordDecls. And it doesn't make sense to create
2730 // duplicated deduction guides for the duplicated constructors.
2731 if (ProcessedCtors
.count(D
))
2734 auto *FTD
= dyn_cast
<FunctionTemplateDecl
>(D
);
2736 dyn_cast_or_null
<CXXConstructorDecl
>(FTD
? FTD
->getTemplatedDecl() : D
);
2737 // Class-scope explicit specializations (MS extension) do not result in
2738 // deduction guides.
2739 if (!CD
|| (!FTD
&& CD
->isFunctionTemplateSpecialization()))
2742 // Cannot make a deduction guide when unparsed arguments are present.
2743 if (llvm::any_of(CD
->parameters(), [](ParmVarDecl
*P
) {
2744 return !P
|| P
->hasUnparsedDefaultArg();
2748 ProcessedCtors
.insert(D
);
2749 Transform
.transformConstructor(FTD
, CD
);
2753 // C++17 [over.match.class.deduct]
2754 // -- If C is not defined or does not declare any constructors, an
2755 // additional function template derived as above from a hypothetical
2758 Transform
.buildSimpleDeductionGuide(std::nullopt
);
2760 // -- An additional function template derived as above from a hypothetical
2761 // constructor C(C), called the copy deduction candidate.
2762 cast
<CXXDeductionGuideDecl
>(
2763 cast
<FunctionTemplateDecl
>(
2764 Transform
.buildSimpleDeductionGuide(Transform
.DeducedType
))
2765 ->getTemplatedDecl())
2766 ->setDeductionCandidateKind(DeductionCandidate::Copy
);
2771 /// Diagnose the presence of a default template argument on a
2772 /// template parameter, which is ill-formed in certain contexts.
2774 /// \returns true if the default template argument should be dropped.
2775 static bool DiagnoseDefaultTemplateArgument(Sema
&S
,
2776 Sema::TemplateParamListContext TPC
,
2777 SourceLocation ParamLoc
,
2778 SourceRange DefArgRange
) {
2780 case Sema::TPC_ClassTemplate
:
2781 case Sema::TPC_VarTemplate
:
2782 case Sema::TPC_TypeAliasTemplate
:
2785 case Sema::TPC_FunctionTemplate
:
2786 case Sema::TPC_FriendFunctionTemplateDefinition
:
2787 // C++ [temp.param]p9:
2788 // A default template-argument shall not be specified in a
2789 // function template declaration or a function template
2791 // If a friend function template declaration specifies a default
2792 // template-argument, that declaration shall be a definition and shall be
2793 // the only declaration of the function template in the translation unit.
2794 // (C++98/03 doesn't have this wording; see DR226).
2795 S
.Diag(ParamLoc
, S
.getLangOpts().CPlusPlus11
?
2796 diag::warn_cxx98_compat_template_parameter_default_in_function_template
2797 : diag::ext_template_parameter_default_in_function_template
)
2801 case Sema::TPC_ClassTemplateMember
:
2802 // C++0x [temp.param]p9:
2803 // A default template-argument shall not be specified in the
2804 // template-parameter-lists of the definition of a member of a
2805 // class template that appears outside of the member's class.
2806 S
.Diag(ParamLoc
, diag::err_template_parameter_default_template_member
)
2810 case Sema::TPC_FriendClassTemplate
:
2811 case Sema::TPC_FriendFunctionTemplate
:
2812 // C++ [temp.param]p9:
2813 // A default template-argument shall not be specified in a
2814 // friend template declaration.
2815 S
.Diag(ParamLoc
, diag::err_template_parameter_default_friend_template
)
2819 // FIXME: C++0x [temp.param]p9 allows default template-arguments
2820 // for friend function templates if there is only a single
2821 // declaration (and it is a definition). Strange!
2824 llvm_unreachable("Invalid TemplateParamListContext!");
2827 /// Check for unexpanded parameter packs within the template parameters
2828 /// of a template template parameter, recursively.
2829 static bool DiagnoseUnexpandedParameterPacks(Sema
&S
,
2830 TemplateTemplateParmDecl
*TTP
) {
2831 // A template template parameter which is a parameter pack is also a pack
2833 if (TTP
->isParameterPack())
2836 TemplateParameterList
*Params
= TTP
->getTemplateParameters();
2837 for (unsigned I
= 0, N
= Params
->size(); I
!= N
; ++I
) {
2838 NamedDecl
*P
= Params
->getParam(I
);
2839 if (TemplateTypeParmDecl
*TTP
= dyn_cast
<TemplateTypeParmDecl
>(P
)) {
2840 if (!TTP
->isParameterPack())
2841 if (const TypeConstraint
*TC
= TTP
->getTypeConstraint())
2842 if (TC
->hasExplicitTemplateArgs())
2843 for (auto &ArgLoc
: TC
->getTemplateArgsAsWritten()->arguments())
2844 if (S
.DiagnoseUnexpandedParameterPack(ArgLoc
,
2845 Sema::UPPC_TypeConstraint
))
2850 if (NonTypeTemplateParmDecl
*NTTP
= dyn_cast
<NonTypeTemplateParmDecl
>(P
)) {
2851 if (!NTTP
->isParameterPack() &&
2852 S
.DiagnoseUnexpandedParameterPack(NTTP
->getLocation(),
2853 NTTP
->getTypeSourceInfo(),
2854 Sema::UPPC_NonTypeTemplateParameterType
))
2860 if (TemplateTemplateParmDecl
*InnerTTP
2861 = dyn_cast
<TemplateTemplateParmDecl
>(P
))
2862 if (DiagnoseUnexpandedParameterPacks(S
, InnerTTP
))
2869 /// Checks the validity of a template parameter list, possibly
2870 /// considering the template parameter list from a previous
2873 /// If an "old" template parameter list is provided, it must be
2874 /// equivalent (per TemplateParameterListsAreEqual) to the "new"
2875 /// template parameter list.
2877 /// \param NewParams Template parameter list for a new template
2878 /// declaration. This template parameter list will be updated with any
2879 /// default arguments that are carried through from the previous
2880 /// template parameter list.
2882 /// \param OldParams If provided, template parameter list from a
2883 /// previous declaration of the same template. Default template
2884 /// arguments will be merged from the old template parameter list to
2885 /// the new template parameter list.
2887 /// \param TPC Describes the context in which we are checking the given
2888 /// template parameter list.
2890 /// \param SkipBody If we might have already made a prior merged definition
2891 /// of this template visible, the corresponding body-skipping information.
2892 /// Default argument redefinition is not an error when skipping such a body,
2893 /// because (under the ODR) we can assume the default arguments are the same
2894 /// as the prior merged definition.
2896 /// \returns true if an error occurred, false otherwise.
2897 bool Sema::CheckTemplateParameterList(TemplateParameterList
*NewParams
,
2898 TemplateParameterList
*OldParams
,
2899 TemplateParamListContext TPC
,
2900 SkipBodyInfo
*SkipBody
) {
2901 bool Invalid
= false;
2903 // C++ [temp.param]p10:
2904 // The set of default template-arguments available for use with a
2905 // template declaration or definition is obtained by merging the
2906 // default arguments from the definition (if in scope) and all
2907 // declarations in scope in the same way default function
2908 // arguments are (8.3.6).
2909 bool SawDefaultArgument
= false;
2910 SourceLocation PreviousDefaultArgLoc
;
2912 // Dummy initialization to avoid warnings.
2913 TemplateParameterList::iterator OldParam
= NewParams
->end();
2915 OldParam
= OldParams
->begin();
2917 bool RemoveDefaultArguments
= false;
2918 for (TemplateParameterList::iterator NewParam
= NewParams
->begin(),
2919 NewParamEnd
= NewParams
->end();
2920 NewParam
!= NewParamEnd
; ++NewParam
) {
2921 // Whether we've seen a duplicate default argument in the same translation
2923 bool RedundantDefaultArg
= false;
2924 // Whether we've found inconsis inconsitent default arguments in different
2925 // translation unit.
2926 bool InconsistentDefaultArg
= false;
2927 // The name of the module which contains the inconsistent default argument.
2928 std::string PrevModuleName
;
2930 SourceLocation OldDefaultLoc
;
2931 SourceLocation NewDefaultLoc
;
2933 // Variable used to diagnose missing default arguments
2934 bool MissingDefaultArg
= false;
2936 // Variable used to diagnose non-final parameter packs
2937 bool SawParameterPack
= false;
2939 if (TemplateTypeParmDecl
*NewTypeParm
2940 = dyn_cast
<TemplateTypeParmDecl
>(*NewParam
)) {
2941 // Check the presence of a default argument here.
2942 if (NewTypeParm
->hasDefaultArgument() &&
2943 DiagnoseDefaultTemplateArgument(*this, TPC
,
2944 NewTypeParm
->getLocation(),
2945 NewTypeParm
->getDefaultArgumentInfo()->getTypeLoc()
2947 NewTypeParm
->removeDefaultArgument();
2949 // Merge default arguments for template type parameters.
2950 TemplateTypeParmDecl
*OldTypeParm
2951 = OldParams
? cast
<TemplateTypeParmDecl
>(*OldParam
) : nullptr;
2952 if (NewTypeParm
->isParameterPack()) {
2953 assert(!NewTypeParm
->hasDefaultArgument() &&
2954 "Parameter packs can't have a default argument!");
2955 SawParameterPack
= true;
2956 } else if (OldTypeParm
&& hasVisibleDefaultArgument(OldTypeParm
) &&
2957 NewTypeParm
->hasDefaultArgument() &&
2958 (!SkipBody
|| !SkipBody
->ShouldSkip
)) {
2959 OldDefaultLoc
= OldTypeParm
->getDefaultArgumentLoc();
2960 NewDefaultLoc
= NewTypeParm
->getDefaultArgumentLoc();
2961 SawDefaultArgument
= true;
2963 if (!OldTypeParm
->getOwningModule())
2964 RedundantDefaultArg
= true;
2965 else if (!getASTContext().isSameDefaultTemplateArgument(OldTypeParm
,
2967 InconsistentDefaultArg
= true;
2969 OldTypeParm
->getImportedOwningModule()->getFullModuleName();
2971 PreviousDefaultArgLoc
= NewDefaultLoc
;
2972 } else if (OldTypeParm
&& OldTypeParm
->hasDefaultArgument()) {
2973 // Merge the default argument from the old declaration to the
2975 NewTypeParm
->setInheritedDefaultArgument(Context
, OldTypeParm
);
2976 PreviousDefaultArgLoc
= OldTypeParm
->getDefaultArgumentLoc();
2977 } else if (NewTypeParm
->hasDefaultArgument()) {
2978 SawDefaultArgument
= true;
2979 PreviousDefaultArgLoc
= NewTypeParm
->getDefaultArgumentLoc();
2980 } else if (SawDefaultArgument
)
2981 MissingDefaultArg
= true;
2982 } else if (NonTypeTemplateParmDecl
*NewNonTypeParm
2983 = dyn_cast
<NonTypeTemplateParmDecl
>(*NewParam
)) {
2984 // Check for unexpanded parameter packs.
2985 if (!NewNonTypeParm
->isParameterPack() &&
2986 DiagnoseUnexpandedParameterPack(NewNonTypeParm
->getLocation(),
2987 NewNonTypeParm
->getTypeSourceInfo(),
2988 UPPC_NonTypeTemplateParameterType
)) {
2993 // Check the presence of a default argument here.
2994 if (NewNonTypeParm
->hasDefaultArgument() &&
2995 DiagnoseDefaultTemplateArgument(*this, TPC
,
2996 NewNonTypeParm
->getLocation(),
2997 NewNonTypeParm
->getDefaultArgument()->getSourceRange())) {
2998 NewNonTypeParm
->removeDefaultArgument();
3001 // Merge default arguments for non-type template parameters
3002 NonTypeTemplateParmDecl
*OldNonTypeParm
3003 = OldParams
? cast
<NonTypeTemplateParmDecl
>(*OldParam
) : nullptr;
3004 if (NewNonTypeParm
->isParameterPack()) {
3005 assert(!NewNonTypeParm
->hasDefaultArgument() &&
3006 "Parameter packs can't have a default argument!");
3007 if (!NewNonTypeParm
->isPackExpansion())
3008 SawParameterPack
= true;
3009 } else if (OldNonTypeParm
&& hasVisibleDefaultArgument(OldNonTypeParm
) &&
3010 NewNonTypeParm
->hasDefaultArgument() &&
3011 (!SkipBody
|| !SkipBody
->ShouldSkip
)) {
3012 OldDefaultLoc
= OldNonTypeParm
->getDefaultArgumentLoc();
3013 NewDefaultLoc
= NewNonTypeParm
->getDefaultArgumentLoc();
3014 SawDefaultArgument
= true;
3015 if (!OldNonTypeParm
->getOwningModule())
3016 RedundantDefaultArg
= true;
3017 else if (!getASTContext().isSameDefaultTemplateArgument(
3018 OldNonTypeParm
, NewNonTypeParm
)) {
3019 InconsistentDefaultArg
= true;
3021 OldNonTypeParm
->getImportedOwningModule()->getFullModuleName();
3023 PreviousDefaultArgLoc
= NewDefaultLoc
;
3024 } else if (OldNonTypeParm
&& OldNonTypeParm
->hasDefaultArgument()) {
3025 // Merge the default argument from the old declaration to the
3027 NewNonTypeParm
->setInheritedDefaultArgument(Context
, OldNonTypeParm
);
3028 PreviousDefaultArgLoc
= OldNonTypeParm
->getDefaultArgumentLoc();
3029 } else if (NewNonTypeParm
->hasDefaultArgument()) {
3030 SawDefaultArgument
= true;
3031 PreviousDefaultArgLoc
= NewNonTypeParm
->getDefaultArgumentLoc();
3032 } else if (SawDefaultArgument
)
3033 MissingDefaultArg
= true;
3035 TemplateTemplateParmDecl
*NewTemplateParm
3036 = cast
<TemplateTemplateParmDecl
>(*NewParam
);
3038 // Check for unexpanded parameter packs, recursively.
3039 if (::DiagnoseUnexpandedParameterPacks(*this, NewTemplateParm
)) {
3044 // Check the presence of a default argument here.
3045 if (NewTemplateParm
->hasDefaultArgument() &&
3046 DiagnoseDefaultTemplateArgument(*this, TPC
,
3047 NewTemplateParm
->getLocation(),
3048 NewTemplateParm
->getDefaultArgument().getSourceRange()))
3049 NewTemplateParm
->removeDefaultArgument();
3051 // Merge default arguments for template template parameters
3052 TemplateTemplateParmDecl
*OldTemplateParm
3053 = OldParams
? cast
<TemplateTemplateParmDecl
>(*OldParam
) : nullptr;
3054 if (NewTemplateParm
->isParameterPack()) {
3055 assert(!NewTemplateParm
->hasDefaultArgument() &&
3056 "Parameter packs can't have a default argument!");
3057 if (!NewTemplateParm
->isPackExpansion())
3058 SawParameterPack
= true;
3059 } else if (OldTemplateParm
&&
3060 hasVisibleDefaultArgument(OldTemplateParm
) &&
3061 NewTemplateParm
->hasDefaultArgument() &&
3062 (!SkipBody
|| !SkipBody
->ShouldSkip
)) {
3063 OldDefaultLoc
= OldTemplateParm
->getDefaultArgument().getLocation();
3064 NewDefaultLoc
= NewTemplateParm
->getDefaultArgument().getLocation();
3065 SawDefaultArgument
= true;
3066 if (!OldTemplateParm
->getOwningModule())
3067 RedundantDefaultArg
= true;
3068 else if (!getASTContext().isSameDefaultTemplateArgument(
3069 OldTemplateParm
, NewTemplateParm
)) {
3070 InconsistentDefaultArg
= true;
3072 OldTemplateParm
->getImportedOwningModule()->getFullModuleName();
3074 PreviousDefaultArgLoc
= NewDefaultLoc
;
3075 } else if (OldTemplateParm
&& OldTemplateParm
->hasDefaultArgument()) {
3076 // Merge the default argument from the old declaration to the
3078 NewTemplateParm
->setInheritedDefaultArgument(Context
, OldTemplateParm
);
3079 PreviousDefaultArgLoc
3080 = OldTemplateParm
->getDefaultArgument().getLocation();
3081 } else if (NewTemplateParm
->hasDefaultArgument()) {
3082 SawDefaultArgument
= true;
3083 PreviousDefaultArgLoc
3084 = NewTemplateParm
->getDefaultArgument().getLocation();
3085 } else if (SawDefaultArgument
)
3086 MissingDefaultArg
= true;
3089 // C++11 [temp.param]p11:
3090 // If a template parameter of a primary class template or alias template
3091 // is a template parameter pack, it shall be the last template parameter.
3092 if (SawParameterPack
&& (NewParam
+ 1) != NewParamEnd
&&
3093 (TPC
== TPC_ClassTemplate
|| TPC
== TPC_VarTemplate
||
3094 TPC
== TPC_TypeAliasTemplate
)) {
3095 Diag((*NewParam
)->getLocation(),
3096 diag::err_template_param_pack_must_be_last_template_parameter
);
3100 // [basic.def.odr]/13:
3101 // There can be more than one definition of a
3103 // default template argument
3105 // in a program provided that each definition appears in a different
3106 // translation unit and the definitions satisfy the [same-meaning
3107 // criteria of the ODR].
3109 // Simply, the design of modules allows the definition of template default
3110 // argument to be repeated across translation unit. Note that the ODR is
3111 // checked elsewhere. But it is still not allowed to repeat template default
3112 // argument in the same translation unit.
3113 if (RedundantDefaultArg
) {
3114 Diag(NewDefaultLoc
, diag::err_template_param_default_arg_redefinition
);
3115 Diag(OldDefaultLoc
, diag::note_template_param_prev_default_arg
);
3117 } else if (InconsistentDefaultArg
) {
3118 // We could only diagnose about the case that the OldParam is imported.
3119 // The case NewParam is imported should be handled in ASTReader.
3121 diag::err_template_param_default_arg_inconsistent_redefinition
);
3123 diag::note_template_param_prev_default_arg_in_other_module
)
3126 } else if (MissingDefaultArg
&& TPC
!= TPC_FunctionTemplate
) {
3127 // C++ [temp.param]p11:
3128 // If a template-parameter of a class template has a default
3129 // template-argument, each subsequent template-parameter shall either
3130 // have a default template-argument supplied or be a template parameter
3132 Diag((*NewParam
)->getLocation(),
3133 diag::err_template_param_default_arg_missing
);
3134 Diag(PreviousDefaultArgLoc
, diag::note_template_param_prev_default_arg
);
3136 RemoveDefaultArguments
= true;
3139 // If we have an old template parameter list that we're merging
3140 // in, move on to the next parameter.
3145 // We were missing some default arguments at the end of the list, so remove
3146 // all of the default arguments.
3147 if (RemoveDefaultArguments
) {
3148 for (TemplateParameterList::iterator NewParam
= NewParams
->begin(),
3149 NewParamEnd
= NewParams
->end();
3150 NewParam
!= NewParamEnd
; ++NewParam
) {
3151 if (TemplateTypeParmDecl
*TTP
= dyn_cast
<TemplateTypeParmDecl
>(*NewParam
))
3152 TTP
->removeDefaultArgument();
3153 else if (NonTypeTemplateParmDecl
*NTTP
3154 = dyn_cast
<NonTypeTemplateParmDecl
>(*NewParam
))
3155 NTTP
->removeDefaultArgument();
3157 cast
<TemplateTemplateParmDecl
>(*NewParam
)->removeDefaultArgument();
3166 /// A class which looks for a use of a certain level of template
3168 struct DependencyChecker
: RecursiveASTVisitor
<DependencyChecker
> {
3169 typedef RecursiveASTVisitor
<DependencyChecker
> super
;
3173 // Whether we're looking for a use of a template parameter that makes the
3174 // overall construct type-dependent / a dependent type. This is strictly
3175 // best-effort for now; we may fail to match at all for a dependent type
3176 // in some cases if this is set.
3177 bool IgnoreNonTypeDependent
;
3180 SourceLocation MatchLoc
;
3182 DependencyChecker(unsigned Depth
, bool IgnoreNonTypeDependent
)
3183 : Depth(Depth
), IgnoreNonTypeDependent(IgnoreNonTypeDependent
),
3186 DependencyChecker(TemplateParameterList
*Params
, bool IgnoreNonTypeDependent
)
3187 : IgnoreNonTypeDependent(IgnoreNonTypeDependent
), Match(false) {
3188 NamedDecl
*ND
= Params
->getParam(0);
3189 if (TemplateTypeParmDecl
*PD
= dyn_cast
<TemplateTypeParmDecl
>(ND
)) {
3190 Depth
= PD
->getDepth();
3191 } else if (NonTypeTemplateParmDecl
*PD
=
3192 dyn_cast
<NonTypeTemplateParmDecl
>(ND
)) {
3193 Depth
= PD
->getDepth();
3195 Depth
= cast
<TemplateTemplateParmDecl
>(ND
)->getDepth();
3199 bool Matches(unsigned ParmDepth
, SourceLocation Loc
= SourceLocation()) {
3200 if (ParmDepth
>= Depth
) {
3208 bool TraverseStmt(Stmt
*S
, DataRecursionQueue
*Q
= nullptr) {
3209 // Prune out non-type-dependent expressions if requested. This can
3210 // sometimes result in us failing to find a template parameter reference
3211 // (if a value-dependent expression creates a dependent type), but this
3212 // mode is best-effort only.
3213 if (auto *E
= dyn_cast_or_null
<Expr
>(S
))
3214 if (IgnoreNonTypeDependent
&& !E
->isTypeDependent())
3216 return super::TraverseStmt(S
, Q
);
3219 bool TraverseTypeLoc(TypeLoc TL
) {
3220 if (IgnoreNonTypeDependent
&& !TL
.isNull() &&
3221 !TL
.getType()->isDependentType())
3223 return super::TraverseTypeLoc(TL
);
3226 bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL
) {
3227 return !Matches(TL
.getTypePtr()->getDepth(), TL
.getNameLoc());
3230 bool VisitTemplateTypeParmType(const TemplateTypeParmType
*T
) {
3231 // For a best-effort search, keep looking until we find a location.
3232 return IgnoreNonTypeDependent
|| !Matches(T
->getDepth());
3235 bool TraverseTemplateName(TemplateName N
) {
3236 if (TemplateTemplateParmDecl
*PD
=
3237 dyn_cast_or_null
<TemplateTemplateParmDecl
>(N
.getAsTemplateDecl()))
3238 if (Matches(PD
->getDepth()))
3240 return super::TraverseTemplateName(N
);
3243 bool VisitDeclRefExpr(DeclRefExpr
*E
) {
3244 if (NonTypeTemplateParmDecl
*PD
=
3245 dyn_cast
<NonTypeTemplateParmDecl
>(E
->getDecl()))
3246 if (Matches(PD
->getDepth(), E
->getExprLoc()))
3248 return super::VisitDeclRefExpr(E
);
3251 bool VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType
*T
) {
3252 return TraverseType(T
->getReplacementType());
3256 VisitSubstTemplateTypeParmPackType(const SubstTemplateTypeParmPackType
*T
) {
3257 return TraverseTemplateArgument(T
->getArgumentPack());
3260 bool TraverseInjectedClassNameType(const InjectedClassNameType
*T
) {
3261 return TraverseType(T
->getInjectedSpecializationType());
3264 } // end anonymous namespace
3266 /// Determines whether a given type depends on the given parameter
3269 DependsOnTemplateParameters(QualType T
, TemplateParameterList
*Params
) {
3270 if (!Params
->size())
3273 DependencyChecker
Checker(Params
, /*IgnoreNonTypeDependent*/false);
3274 Checker
.TraverseType(T
);
3275 return Checker
.Match
;
3278 // Find the source range corresponding to the named type in the given
3279 // nested-name-specifier, if any.
3280 static SourceRange
getRangeOfTypeInNestedNameSpecifier(ASTContext
&Context
,
3282 const CXXScopeSpec
&SS
) {
3283 NestedNameSpecifierLoc
NNSLoc(SS
.getScopeRep(), SS
.location_data());
3284 while (NestedNameSpecifier
*NNS
= NNSLoc
.getNestedNameSpecifier()) {
3285 if (const Type
*CurType
= NNS
->getAsType()) {
3286 if (Context
.hasSameUnqualifiedType(T
, QualType(CurType
, 0)))
3287 return NNSLoc
.getTypeLoc().getSourceRange();
3291 NNSLoc
= NNSLoc
.getPrefix();
3294 return SourceRange();
3297 /// Match the given template parameter lists to the given scope
3298 /// specifier, returning the template parameter list that applies to the
3301 /// \param DeclStartLoc the start of the declaration that has a scope
3302 /// specifier or a template parameter list.
3304 /// \param DeclLoc The location of the declaration itself.
3306 /// \param SS the scope specifier that will be matched to the given template
3307 /// parameter lists. This scope specifier precedes a qualified name that is
3310 /// \param TemplateId The template-id following the scope specifier, if there
3311 /// is one. Used to check for a missing 'template<>'.
3313 /// \param ParamLists the template parameter lists, from the outermost to the
3314 /// innermost template parameter lists.
3316 /// \param IsFriend Whether to apply the slightly different rules for
3317 /// matching template parameters to scope specifiers in friend
3320 /// \param IsMemberSpecialization will be set true if the scope specifier
3321 /// denotes a fully-specialized type, and therefore this is a declaration of
3322 /// a member specialization.
3324 /// \returns the template parameter list, if any, that corresponds to the
3325 /// name that is preceded by the scope specifier @p SS. This template
3326 /// parameter list may have template parameters (if we're declaring a
3327 /// template) or may have no template parameters (if we're declaring a
3328 /// template specialization), or may be NULL (if what we're declaring isn't
3329 /// itself a template).
3330 TemplateParameterList
*Sema::MatchTemplateParametersToScopeSpecifier(
3331 SourceLocation DeclStartLoc
, SourceLocation DeclLoc
, const CXXScopeSpec
&SS
,
3332 TemplateIdAnnotation
*TemplateId
,
3333 ArrayRef
<TemplateParameterList
*> ParamLists
, bool IsFriend
,
3334 bool &IsMemberSpecialization
, bool &Invalid
, bool SuppressDiagnostic
) {
3335 IsMemberSpecialization
= false;
3338 // The sequence of nested types to which we will match up the template
3339 // parameter lists. We first build this list by starting with the type named
3340 // by the nested-name-specifier and walking out until we run out of types.
3341 SmallVector
<QualType
, 4> NestedTypes
;
3343 if (SS
.getScopeRep()) {
3344 if (CXXRecordDecl
*Record
3345 = dyn_cast_or_null
<CXXRecordDecl
>(computeDeclContext(SS
, true)))
3346 T
= Context
.getTypeDeclType(Record
);
3348 T
= QualType(SS
.getScopeRep()->getAsType(), 0);
3351 // If we found an explicit specialization that prevents us from needing
3352 // 'template<>' headers, this will be set to the location of that
3353 // explicit specialization.
3354 SourceLocation ExplicitSpecLoc
;
3356 while (!T
.isNull()) {
3357 NestedTypes
.push_back(T
);
3359 // Retrieve the parent of a record type.
3360 if (CXXRecordDecl
*Record
= T
->getAsCXXRecordDecl()) {
3361 // If this type is an explicit specialization, we're done.
3362 if (ClassTemplateSpecializationDecl
*Spec
3363 = dyn_cast
<ClassTemplateSpecializationDecl
>(Record
)) {
3364 if (!isa
<ClassTemplatePartialSpecializationDecl
>(Spec
) &&
3365 Spec
->getSpecializationKind() == TSK_ExplicitSpecialization
) {
3366 ExplicitSpecLoc
= Spec
->getLocation();
3369 } else if (Record
->getTemplateSpecializationKind()
3370 == TSK_ExplicitSpecialization
) {
3371 ExplicitSpecLoc
= Record
->getLocation();
3375 if (TypeDecl
*Parent
= dyn_cast
<TypeDecl
>(Record
->getParent()))
3376 T
= Context
.getTypeDeclType(Parent
);
3382 if (const TemplateSpecializationType
*TST
3383 = T
->getAs
<TemplateSpecializationType
>()) {
3384 if (TemplateDecl
*Template
= TST
->getTemplateName().getAsTemplateDecl()) {
3385 if (TypeDecl
*Parent
= dyn_cast
<TypeDecl
>(Template
->getDeclContext()))
3386 T
= Context
.getTypeDeclType(Parent
);
3393 // Look one step prior in a dependent template specialization type.
3394 if (const DependentTemplateSpecializationType
*DependentTST
3395 = T
->getAs
<DependentTemplateSpecializationType
>()) {
3396 if (NestedNameSpecifier
*NNS
= DependentTST
->getQualifier())
3397 T
= QualType(NNS
->getAsType(), 0);
3403 // Look one step prior in a dependent name type.
3404 if (const DependentNameType
*DependentName
= T
->getAs
<DependentNameType
>()){
3405 if (NestedNameSpecifier
*NNS
= DependentName
->getQualifier())
3406 T
= QualType(NNS
->getAsType(), 0);
3412 // Retrieve the parent of an enumeration type.
3413 if (const EnumType
*EnumT
= T
->getAs
<EnumType
>()) {
3414 // FIXME: Forward-declared enums require a TSK_ExplicitSpecialization
3416 EnumDecl
*Enum
= EnumT
->getDecl();
3418 // Get to the parent type.
3419 if (TypeDecl
*Parent
= dyn_cast
<TypeDecl
>(Enum
->getParent()))
3420 T
= Context
.getTypeDeclType(Parent
);
3428 // Reverse the nested types list, since we want to traverse from the outermost
3429 // to the innermost while checking template-parameter-lists.
3430 std::reverse(NestedTypes
.begin(), NestedTypes
.end());
3432 // C++0x [temp.expl.spec]p17:
3433 // A member or a member template may be nested within many
3434 // enclosing class templates. In an explicit specialization for
3435 // such a member, the member declaration shall be preceded by a
3436 // template<> for each enclosing class template that is
3437 // explicitly specialized.
3438 bool SawNonEmptyTemplateParameterList
= false;
3440 auto CheckExplicitSpecialization
= [&](SourceRange Range
, bool Recovery
) {
3441 if (SawNonEmptyTemplateParameterList
) {
3442 if (!SuppressDiagnostic
)
3443 Diag(DeclLoc
, diag::err_specialize_member_of_template
)
3444 << !Recovery
<< Range
;
3446 IsMemberSpecialization
= false;
3453 auto DiagnoseMissingExplicitSpecialization
= [&] (SourceRange Range
) {
3454 // Check that we can have an explicit specialization here.
3455 if (CheckExplicitSpecialization(Range
, true))
3458 // We don't have a template header, but we should.
3459 SourceLocation ExpectedTemplateLoc
;
3460 if (!ParamLists
.empty())
3461 ExpectedTemplateLoc
= ParamLists
[0]->getTemplateLoc();
3463 ExpectedTemplateLoc
= DeclStartLoc
;
3465 if (!SuppressDiagnostic
)
3466 Diag(DeclLoc
, diag::err_template_spec_needs_header
)
3468 << FixItHint::CreateInsertion(ExpectedTemplateLoc
, "template<> ");
3472 unsigned ParamIdx
= 0;
3473 for (unsigned TypeIdx
= 0, NumTypes
= NestedTypes
.size(); TypeIdx
!= NumTypes
;
3475 T
= NestedTypes
[TypeIdx
];
3477 // Whether we expect a 'template<>' header.
3478 bool NeedEmptyTemplateHeader
= false;
3480 // Whether we expect a template header with parameters.
3481 bool NeedNonemptyTemplateHeader
= false;
3483 // For a dependent type, the set of template parameters that we
3485 TemplateParameterList
*ExpectedTemplateParams
= nullptr;
3487 // C++0x [temp.expl.spec]p15:
3488 // A member or a member template may be nested within many enclosing
3489 // class templates. In an explicit specialization for such a member, the
3490 // member declaration shall be preceded by a template<> for each
3491 // enclosing class template that is explicitly specialized.
3492 if (CXXRecordDecl
*Record
= T
->getAsCXXRecordDecl()) {
3493 if (ClassTemplatePartialSpecializationDecl
*Partial
3494 = dyn_cast
<ClassTemplatePartialSpecializationDecl
>(Record
)) {
3495 ExpectedTemplateParams
= Partial
->getTemplateParameters();
3496 NeedNonemptyTemplateHeader
= true;
3497 } else if (Record
->isDependentType()) {
3498 if (Record
->getDescribedClassTemplate()) {
3499 ExpectedTemplateParams
= Record
->getDescribedClassTemplate()
3500 ->getTemplateParameters();
3501 NeedNonemptyTemplateHeader
= true;
3503 } else if (ClassTemplateSpecializationDecl
*Spec
3504 = dyn_cast
<ClassTemplateSpecializationDecl
>(Record
)) {
3505 // C++0x [temp.expl.spec]p4:
3506 // Members of an explicitly specialized class template are defined
3507 // in the same manner as members of normal classes, and not using
3508 // the template<> syntax.
3509 if (Spec
->getSpecializationKind() != TSK_ExplicitSpecialization
)
3510 NeedEmptyTemplateHeader
= true;
3513 } else if (Record
->getTemplateSpecializationKind()) {
3514 if (Record
->getTemplateSpecializationKind()
3515 != TSK_ExplicitSpecialization
&&
3516 TypeIdx
== NumTypes
- 1)
3517 IsMemberSpecialization
= true;
3521 } else if (const TemplateSpecializationType
*TST
3522 = T
->getAs
<TemplateSpecializationType
>()) {
3523 if (TemplateDecl
*Template
= TST
->getTemplateName().getAsTemplateDecl()) {
3524 ExpectedTemplateParams
= Template
->getTemplateParameters();
3525 NeedNonemptyTemplateHeader
= true;
3527 } else if (T
->getAs
<DependentTemplateSpecializationType
>()) {
3528 // FIXME: We actually could/should check the template arguments here
3529 // against the corresponding template parameter list.
3530 NeedNonemptyTemplateHeader
= false;
3533 // C++ [temp.expl.spec]p16:
3534 // In an explicit specialization declaration for a member of a class
3535 // template or a member template that ap- pears in namespace scope, the
3536 // member template and some of its enclosing class templates may remain
3537 // unspecialized, except that the declaration shall not explicitly
3538 // specialize a class member template if its en- closing class templates
3539 // are not explicitly specialized as well.
3540 if (ParamIdx
< ParamLists
.size()) {
3541 if (ParamLists
[ParamIdx
]->size() == 0) {
3542 if (CheckExplicitSpecialization(ParamLists
[ParamIdx
]->getSourceRange(),
3546 SawNonEmptyTemplateParameterList
= true;
3549 if (NeedEmptyTemplateHeader
) {
3550 // If we're on the last of the types, and we need a 'template<>' header
3551 // here, then it's a member specialization.
3552 if (TypeIdx
== NumTypes
- 1)
3553 IsMemberSpecialization
= true;
3555 if (ParamIdx
< ParamLists
.size()) {
3556 if (ParamLists
[ParamIdx
]->size() > 0) {
3557 // The header has template parameters when it shouldn't. Complain.
3558 if (!SuppressDiagnostic
)
3559 Diag(ParamLists
[ParamIdx
]->getTemplateLoc(),
3560 diag::err_template_param_list_matches_nontemplate
)
3562 << SourceRange(ParamLists
[ParamIdx
]->getLAngleLoc(),
3563 ParamLists
[ParamIdx
]->getRAngleLoc())
3564 << getRangeOfTypeInNestedNameSpecifier(Context
, T
, SS
);
3569 // Consume this template header.
3575 if (DiagnoseMissingExplicitSpecialization(
3576 getRangeOfTypeInNestedNameSpecifier(Context
, T
, SS
)))
3582 if (NeedNonemptyTemplateHeader
) {
3583 // In friend declarations we can have template-ids which don't
3584 // depend on the corresponding template parameter lists. But
3585 // assume that empty parameter lists are supposed to match this
3587 if (IsFriend
&& T
->isDependentType()) {
3588 if (ParamIdx
< ParamLists
.size() &&
3589 DependsOnTemplateParameters(T
, ParamLists
[ParamIdx
]))
3590 ExpectedTemplateParams
= nullptr;
3595 if (ParamIdx
< ParamLists
.size()) {
3596 // Check the template parameter list, if we can.
3597 if (ExpectedTemplateParams
&&
3598 !TemplateParameterListsAreEqual(ParamLists
[ParamIdx
],
3599 ExpectedTemplateParams
,
3600 !SuppressDiagnostic
, TPL_TemplateMatch
))
3604 CheckTemplateParameterList(ParamLists
[ParamIdx
], nullptr,
3605 TPC_ClassTemplateMember
))
3612 if (!SuppressDiagnostic
)
3613 Diag(DeclLoc
, diag::err_template_spec_needs_template_parameters
)
3615 << getRangeOfTypeInNestedNameSpecifier(Context
, T
, SS
);
3621 // If there were at least as many template-ids as there were template
3622 // parameter lists, then there are no template parameter lists remaining for
3623 // the declaration itself.
3624 if (ParamIdx
>= ParamLists
.size()) {
3625 if (TemplateId
&& !IsFriend
) {
3626 // We don't have a template header for the declaration itself, but we
3628 DiagnoseMissingExplicitSpecialization(SourceRange(TemplateId
->LAngleLoc
,
3629 TemplateId
->RAngleLoc
));
3631 // Fabricate an empty template parameter list for the invented header.
3632 return TemplateParameterList::Create(Context
, SourceLocation(),
3633 SourceLocation(), std::nullopt
,
3634 SourceLocation(), nullptr);
3640 // If there were too many template parameter lists, complain about that now.
3641 if (ParamIdx
< ParamLists
.size() - 1) {
3642 bool HasAnyExplicitSpecHeader
= false;
3643 bool AllExplicitSpecHeaders
= true;
3644 for (unsigned I
= ParamIdx
, E
= ParamLists
.size() - 1; I
!= E
; ++I
) {
3645 if (ParamLists
[I
]->size() == 0)
3646 HasAnyExplicitSpecHeader
= true;
3648 AllExplicitSpecHeaders
= false;
3651 if (!SuppressDiagnostic
)
3652 Diag(ParamLists
[ParamIdx
]->getTemplateLoc(),
3653 AllExplicitSpecHeaders
? diag::warn_template_spec_extra_headers
3654 : diag::err_template_spec_extra_headers
)
3655 << SourceRange(ParamLists
[ParamIdx
]->getTemplateLoc(),
3656 ParamLists
[ParamLists
.size() - 2]->getRAngleLoc());
3658 // If there was a specialization somewhere, such that 'template<>' is
3659 // not required, and there were any 'template<>' headers, note where the
3660 // specialization occurred.
3661 if (ExplicitSpecLoc
.isValid() && HasAnyExplicitSpecHeader
&&
3662 !SuppressDiagnostic
)
3663 Diag(ExplicitSpecLoc
,
3664 diag::note_explicit_template_spec_does_not_need_header
)
3665 << NestedTypes
.back();
3667 // We have a template parameter list with no corresponding scope, which
3668 // means that the resulting template declaration can't be instantiated
3669 // properly (we'll end up with dependent nodes when we shouldn't).
3670 if (!AllExplicitSpecHeaders
)
3674 // C++ [temp.expl.spec]p16:
3675 // In an explicit specialization declaration for a member of a class
3676 // template or a member template that ap- pears in namespace scope, the
3677 // member template and some of its enclosing class templates may remain
3678 // unspecialized, except that the declaration shall not explicitly
3679 // specialize a class member template if its en- closing class templates
3680 // are not explicitly specialized as well.
3681 if (ParamLists
.back()->size() == 0 &&
3682 CheckExplicitSpecialization(ParamLists
[ParamIdx
]->getSourceRange(),
3686 // Return the last template parameter list, which corresponds to the
3687 // entity being declared.
3688 return ParamLists
.back();
3691 void Sema::NoteAllFoundTemplates(TemplateName Name
) {
3692 if (TemplateDecl
*Template
= Name
.getAsTemplateDecl()) {
3693 Diag(Template
->getLocation(), diag::note_template_declared_here
)
3694 << (isa
<FunctionTemplateDecl
>(Template
)
3696 : isa
<ClassTemplateDecl
>(Template
)
3698 : isa
<VarTemplateDecl
>(Template
)
3700 : isa
<TypeAliasTemplateDecl
>(Template
) ? 3 : 4)
3701 << Template
->getDeclName();
3705 if (OverloadedTemplateStorage
*OST
= Name
.getAsOverloadedTemplate()) {
3706 for (OverloadedTemplateStorage::iterator I
= OST
->begin(),
3709 Diag((*I
)->getLocation(), diag::note_template_declared_here
)
3710 << 0 << (*I
)->getDeclName();
3717 checkBuiltinTemplateIdType(Sema
&SemaRef
, BuiltinTemplateDecl
*BTD
,
3718 ArrayRef
<TemplateArgument
> Converted
,
3719 SourceLocation TemplateLoc
,
3720 TemplateArgumentListInfo
&TemplateArgs
) {
3721 ASTContext
&Context
= SemaRef
.getASTContext();
3723 switch (BTD
->getBuiltinTemplateKind()) {
3724 case BTK__make_integer_seq
: {
3725 // Specializations of __make_integer_seq<S, T, N> are treated like
3726 // S<T, 0, ..., N-1>.
3728 QualType OrigType
= Converted
[1].getAsType();
3729 // C++14 [inteseq.intseq]p1:
3730 // T shall be an integer type.
3731 if (!OrigType
->isDependentType() && !OrigType
->isIntegralType(Context
)) {
3732 SemaRef
.Diag(TemplateArgs
[1].getLocation(),
3733 diag::err_integer_sequence_integral_element_type
);
3737 TemplateArgument NumArgsArg
= Converted
[2];
3738 if (NumArgsArg
.isDependent())
3739 return Context
.getCanonicalTemplateSpecializationType(TemplateName(BTD
),
3742 TemplateArgumentListInfo SyntheticTemplateArgs
;
3743 // The type argument, wrapped in substitution sugar, gets reused as the
3744 // first template argument in the synthetic template argument list.
3745 SyntheticTemplateArgs
.addArgument(
3746 TemplateArgumentLoc(TemplateArgument(OrigType
),
3747 SemaRef
.Context
.getTrivialTypeSourceInfo(
3748 OrigType
, TemplateArgs
[1].getLocation())));
3750 if (llvm::APSInt NumArgs
= NumArgsArg
.getAsIntegral(); NumArgs
>= 0) {
3751 // Expand N into 0 ... N-1.
3752 for (llvm::APSInt
I(NumArgs
.getBitWidth(), NumArgs
.isUnsigned());
3754 TemplateArgument
TA(Context
, I
, OrigType
);
3755 SyntheticTemplateArgs
.addArgument(SemaRef
.getTrivialTemplateArgumentLoc(
3756 TA
, OrigType
, TemplateArgs
[2].getLocation()));
3759 // C++14 [inteseq.make]p1:
3760 // If N is negative the program is ill-formed.
3761 SemaRef
.Diag(TemplateArgs
[2].getLocation(),
3762 diag::err_integer_sequence_negative_length
);
3766 // The first template argument will be reused as the template decl that
3767 // our synthetic template arguments will be applied to.
3768 return SemaRef
.CheckTemplateIdType(Converted
[0].getAsTemplate(),
3769 TemplateLoc
, SyntheticTemplateArgs
);
3772 case BTK__type_pack_element
:
3773 // Specializations of
3774 // __type_pack_element<Index, T_1, ..., T_N>
3775 // are treated like T_Index.
3776 assert(Converted
.size() == 2 &&
3777 "__type_pack_element should be given an index and a parameter pack");
3779 TemplateArgument IndexArg
= Converted
[0], Ts
= Converted
[1];
3780 if (IndexArg
.isDependent() || Ts
.isDependent())
3781 return Context
.getCanonicalTemplateSpecializationType(TemplateName(BTD
),
3784 llvm::APSInt Index
= IndexArg
.getAsIntegral();
3785 assert(Index
>= 0 && "the index used with __type_pack_element should be of "
3786 "type std::size_t, and hence be non-negative");
3787 // If the Index is out of bounds, the program is ill-formed.
3788 if (Index
>= Ts
.pack_size()) {
3789 SemaRef
.Diag(TemplateArgs
[0].getLocation(),
3790 diag::err_type_pack_element_out_of_bounds
);
3794 // We simply return the type at index `Index`.
3795 int64_t N
= Index
.getExtValue();
3796 return Ts
.getPackAsArray()[N
].getAsType();
3798 llvm_unreachable("unexpected BuiltinTemplateDecl!");
3801 /// Determine whether this alias template is "enable_if_t".
3802 /// libc++ >=14 uses "__enable_if_t" in C++11 mode.
3803 static bool isEnableIfAliasTemplate(TypeAliasTemplateDecl
*AliasTemplate
) {
3804 return AliasTemplate
->getName().equals("enable_if_t") ||
3805 AliasTemplate
->getName().equals("__enable_if_t");
3808 /// Collect all of the separable terms in the given condition, which
3809 /// might be a conjunction.
3811 /// FIXME: The right answer is to convert the logical expression into
3812 /// disjunctive normal form, so we can find the first failed term
3813 /// within each possible clause.
3814 static void collectConjunctionTerms(Expr
*Clause
,
3815 SmallVectorImpl
<Expr
*> &Terms
) {
3816 if (auto BinOp
= dyn_cast
<BinaryOperator
>(Clause
->IgnoreParenImpCasts())) {
3817 if (BinOp
->getOpcode() == BO_LAnd
) {
3818 collectConjunctionTerms(BinOp
->getLHS(), Terms
);
3819 collectConjunctionTerms(BinOp
->getRHS(), Terms
);
3824 Terms
.push_back(Clause
);
3827 // The ranges-v3 library uses an odd pattern of a top-level "||" with
3828 // a left-hand side that is value-dependent but never true. Identify
3829 // the idiom and ignore that term.
3830 static Expr
*lookThroughRangesV3Condition(Preprocessor
&PP
, Expr
*Cond
) {
3832 auto *BinOp
= dyn_cast
<BinaryOperator
>(Cond
->IgnoreParenImpCasts());
3833 if (!BinOp
) return Cond
;
3835 if (BinOp
->getOpcode() != BO_LOr
) return Cond
;
3837 // With an inner '==' that has a literal on the right-hand side.
3838 Expr
*LHS
= BinOp
->getLHS();
3839 auto *InnerBinOp
= dyn_cast
<BinaryOperator
>(LHS
->IgnoreParenImpCasts());
3840 if (!InnerBinOp
) return Cond
;
3842 if (InnerBinOp
->getOpcode() != BO_EQ
||
3843 !isa
<IntegerLiteral
>(InnerBinOp
->getRHS()))
3846 // If the inner binary operation came from a macro expansion named
3847 // CONCEPT_REQUIRES or CONCEPT_REQUIRES_, return the right-hand side
3848 // of the '||', which is the real, user-provided condition.
3849 SourceLocation Loc
= InnerBinOp
->getExprLoc();
3850 if (!Loc
.isMacroID()) return Cond
;
3852 StringRef MacroName
= PP
.getImmediateMacroName(Loc
);
3853 if (MacroName
== "CONCEPT_REQUIRES" || MacroName
== "CONCEPT_REQUIRES_")
3854 return BinOp
->getRHS();
3861 // A PrinterHelper that prints more helpful diagnostics for some sub-expressions
3862 // within failing boolean expression, such as substituting template parameters
3863 // for actual types.
3864 class FailedBooleanConditionPrinterHelper
: public PrinterHelper
{
3866 explicit FailedBooleanConditionPrinterHelper(const PrintingPolicy
&P
)
3869 bool handledStmt(Stmt
*E
, raw_ostream
&OS
) override
{
3870 const auto *DR
= dyn_cast
<DeclRefExpr
>(E
);
3871 if (DR
&& DR
->getQualifier()) {
3872 // If this is a qualified name, expand the template arguments in nested
3874 DR
->getQualifier()->print(OS
, Policy
, true);
3875 // Then print the decl itself.
3876 const ValueDecl
*VD
= DR
->getDecl();
3877 OS
<< VD
->getName();
3878 if (const auto *IV
= dyn_cast
<VarTemplateSpecializationDecl
>(VD
)) {
3879 // This is a template variable, print the expanded template arguments.
3880 printTemplateArgumentList(
3881 OS
, IV
->getTemplateArgs().asArray(), Policy
,
3882 IV
->getSpecializedTemplate()->getTemplateParameters());
3890 const PrintingPolicy Policy
;
3893 } // end anonymous namespace
3895 std::pair
<Expr
*, std::string
>
3896 Sema::findFailedBooleanCondition(Expr
*Cond
) {
3897 Cond
= lookThroughRangesV3Condition(PP
, Cond
);
3899 // Separate out all of the terms in a conjunction.
3900 SmallVector
<Expr
*, 4> Terms
;
3901 collectConjunctionTerms(Cond
, Terms
);
3903 // Determine which term failed.
3904 Expr
*FailedCond
= nullptr;
3905 for (Expr
*Term
: Terms
) {
3906 Expr
*TermAsWritten
= Term
->IgnoreParenImpCasts();
3908 // Literals are uninteresting.
3909 if (isa
<CXXBoolLiteralExpr
>(TermAsWritten
) ||
3910 isa
<IntegerLiteral
>(TermAsWritten
))
3913 // The initialization of the parameter from the argument is
3914 // a constant-evaluated context.
3915 EnterExpressionEvaluationContext
ConstantEvaluated(
3916 *this, Sema::ExpressionEvaluationContext::ConstantEvaluated
);
3919 if (Term
->EvaluateAsBooleanCondition(Succeeded
, Context
) &&
3921 FailedCond
= TermAsWritten
;
3926 FailedCond
= Cond
->IgnoreParenImpCasts();
3928 std::string Description
;
3930 llvm::raw_string_ostream
Out(Description
);
3931 PrintingPolicy Policy
= getPrintingPolicy();
3932 Policy
.PrintCanonicalTypes
= true;
3933 FailedBooleanConditionPrinterHelper
Helper(Policy
);
3934 FailedCond
->printPretty(Out
, &Helper
, Policy
, 0, "\n", nullptr);
3936 return { FailedCond
, Description
};
3939 QualType
Sema::CheckTemplateIdType(TemplateName Name
,
3940 SourceLocation TemplateLoc
,
3941 TemplateArgumentListInfo
&TemplateArgs
) {
3942 DependentTemplateName
*DTN
3943 = Name
.getUnderlying().getAsDependentTemplateName();
3944 if (DTN
&& DTN
->isIdentifier())
3945 // When building a template-id where the template-name is dependent,
3946 // assume the template is a type template. Either our assumption is
3947 // correct, or the code is ill-formed and will be diagnosed when the
3948 // dependent name is substituted.
3949 return Context
.getDependentTemplateSpecializationType(
3950 ElaboratedTypeKeyword::None
, DTN
->getQualifier(), DTN
->getIdentifier(),
3951 TemplateArgs
.arguments());
3953 if (Name
.getAsAssumedTemplateName() &&
3954 resolveAssumedTemplateNameAsType(/*Scope*/nullptr, Name
, TemplateLoc
))
3957 TemplateDecl
*Template
= Name
.getAsTemplateDecl();
3958 if (!Template
|| isa
<FunctionTemplateDecl
>(Template
) ||
3959 isa
<VarTemplateDecl
>(Template
) || isa
<ConceptDecl
>(Template
)) {
3960 // We might have a substituted template template parameter pack. If so,
3961 // build a template specialization type for it.
3962 if (Name
.getAsSubstTemplateTemplateParmPack())
3963 return Context
.getTemplateSpecializationType(Name
,
3964 TemplateArgs
.arguments());
3966 Diag(TemplateLoc
, diag::err_template_id_not_a_type
)
3968 NoteAllFoundTemplates(Name
);
3972 // Check that the template argument list is well-formed for this
3974 SmallVector
<TemplateArgument
, 4> SugaredConverted
, CanonicalConverted
;
3975 if (CheckTemplateArgumentList(Template
, TemplateLoc
, TemplateArgs
, false,
3976 SugaredConverted
, CanonicalConverted
,
3977 /*UpdateArgsWithConversions=*/true))
3982 if (TypeAliasTemplateDecl
*AliasTemplate
=
3983 dyn_cast
<TypeAliasTemplateDecl
>(Template
)) {
3985 // Find the canonical type for this type alias template specialization.
3986 TypeAliasDecl
*Pattern
= AliasTemplate
->getTemplatedDecl();
3987 if (Pattern
->isInvalidDecl())
3990 // Only substitute for the innermost template argument list.
3991 MultiLevelTemplateArgumentList TemplateArgLists
;
3992 TemplateArgLists
.addOuterTemplateArguments(Template
, CanonicalConverted
,
3994 TemplateArgLists
.addOuterRetainedLevels(
3995 AliasTemplate
->getTemplateParameters()->getDepth());
3997 LocalInstantiationScope
Scope(*this);
3998 InstantiatingTemplate
Inst(*this, TemplateLoc
, Template
);
3999 if (Inst
.isInvalid())
4002 CanonType
= SubstType(Pattern
->getUnderlyingType(),
4003 TemplateArgLists
, AliasTemplate
->getLocation(),
4004 AliasTemplate
->getDeclName());
4005 if (CanonType
.isNull()) {
4006 // If this was enable_if and we failed to find the nested type
4007 // within enable_if in a SFINAE context, dig out the specific
4008 // enable_if condition that failed and present that instead.
4009 if (isEnableIfAliasTemplate(AliasTemplate
)) {
4010 if (auto DeductionInfo
= isSFINAEContext()) {
4011 if (*DeductionInfo
&&
4012 (*DeductionInfo
)->hasSFINAEDiagnostic() &&
4013 (*DeductionInfo
)->peekSFINAEDiagnostic().second
.getDiagID() ==
4014 diag::err_typename_nested_not_found_enable_if
&&
4015 TemplateArgs
[0].getArgument().getKind()
4016 == TemplateArgument::Expression
) {
4018 std::string FailedDescription
;
4019 std::tie(FailedCond
, FailedDescription
) =
4020 findFailedBooleanCondition(TemplateArgs
[0].getSourceExpression());
4022 // Remove the old SFINAE diagnostic.
4023 PartialDiagnosticAt OldDiag
=
4024 {SourceLocation(), PartialDiagnostic::NullDiagnostic()};
4025 (*DeductionInfo
)->takeSFINAEDiagnostic(OldDiag
);
4027 // Add a new SFINAE diagnostic specifying which condition
4029 (*DeductionInfo
)->addSFINAEDiagnostic(
4031 PDiag(diag::err_typename_nested_not_found_requirement
)
4032 << FailedDescription
4033 << FailedCond
->getSourceRange());
4040 } else if (auto *BTD
= dyn_cast
<BuiltinTemplateDecl
>(Template
)) {
4041 CanonType
= checkBuiltinTemplateIdType(*this, BTD
, SugaredConverted
,
4042 TemplateLoc
, TemplateArgs
);
4043 } else if (Name
.isDependent() ||
4044 TemplateSpecializationType::anyDependentTemplateArguments(
4045 TemplateArgs
, CanonicalConverted
)) {
4046 // This class template specialization is a dependent
4047 // type. Therefore, its canonical type is another class template
4048 // specialization type that contains all of the converted
4049 // arguments in canonical form. This ensures that, e.g., A<T> and
4050 // A<T, T> have identical types when A is declared as:
4052 // template<typename T, typename U = T> struct A;
4053 CanonType
= Context
.getCanonicalTemplateSpecializationType(
4054 Name
, CanonicalConverted
);
4056 // This might work out to be a current instantiation, in which
4057 // case the canonical type needs to be the InjectedClassNameType.
4059 // TODO: in theory this could be a simple hashtable lookup; most
4060 // changes to CurContext don't change the set of current
4062 if (isa
<ClassTemplateDecl
>(Template
)) {
4063 for (DeclContext
*Ctx
= CurContext
; Ctx
; Ctx
= Ctx
->getLookupParent()) {
4064 // If we get out to a namespace, we're done.
4065 if (Ctx
->isFileContext()) break;
4067 // If this isn't a record, keep looking.
4068 CXXRecordDecl
*Record
= dyn_cast
<CXXRecordDecl
>(Ctx
);
4069 if (!Record
) continue;
4071 // Look for one of the two cases with InjectedClassNameTypes
4072 // and check whether it's the same template.
4073 if (!isa
<ClassTemplatePartialSpecializationDecl
>(Record
) &&
4074 !Record
->getDescribedClassTemplate())
4077 // Fetch the injected class name type and check whether its
4078 // injected type is equal to the type we just built.
4079 QualType ICNT
= Context
.getTypeDeclType(Record
);
4080 QualType Injected
= cast
<InjectedClassNameType
>(ICNT
)
4081 ->getInjectedSpecializationType();
4083 if (CanonType
!= Injected
->getCanonicalTypeInternal())
4086 // If so, the canonical type of this TST is the injected
4087 // class name type of the record we just found.
4088 assert(ICNT
.isCanonical());
4093 } else if (ClassTemplateDecl
*ClassTemplate
=
4094 dyn_cast
<ClassTemplateDecl
>(Template
)) {
4095 // Find the class template specialization declaration that
4096 // corresponds to these arguments.
4097 void *InsertPos
= nullptr;
4098 ClassTemplateSpecializationDecl
*Decl
=
4099 ClassTemplate
->findSpecialization(CanonicalConverted
, InsertPos
);
4101 // This is the first time we have referenced this class template
4102 // specialization. Create the canonical declaration and add it to
4103 // the set of specializations.
4104 Decl
= ClassTemplateSpecializationDecl::Create(
4105 Context
, ClassTemplate
->getTemplatedDecl()->getTagKind(),
4106 ClassTemplate
->getDeclContext(),
4107 ClassTemplate
->getTemplatedDecl()->getBeginLoc(),
4108 ClassTemplate
->getLocation(), ClassTemplate
, CanonicalConverted
,
4110 ClassTemplate
->AddSpecialization(Decl
, InsertPos
);
4111 if (ClassTemplate
->isOutOfLine())
4112 Decl
->setLexicalDeclContext(ClassTemplate
->getLexicalDeclContext());
4115 if (Decl
->getSpecializationKind() == TSK_Undeclared
&&
4116 ClassTemplate
->getTemplatedDecl()->hasAttrs()) {
4117 InstantiatingTemplate
Inst(*this, TemplateLoc
, Decl
);
4118 if (!Inst
.isInvalid()) {
4119 MultiLevelTemplateArgumentList
TemplateArgLists(Template
,
4122 InstantiateAttrsForDecl(TemplateArgLists
,
4123 ClassTemplate
->getTemplatedDecl(), Decl
);
4127 // Diagnose uses of this specialization.
4128 (void)DiagnoseUseOfDecl(Decl
, TemplateLoc
);
4130 CanonType
= Context
.getTypeDeclType(Decl
);
4131 assert(isa
<RecordType
>(CanonType
) &&
4132 "type of non-dependent specialization is not a RecordType");
4134 llvm_unreachable("Unhandled template kind");
4137 // Build the fully-sugared type for this class template
4138 // specialization, which refers back to the class template
4139 // specialization we created or found.
4140 return Context
.getTemplateSpecializationType(Name
, TemplateArgs
.arguments(),
4144 void Sema::ActOnUndeclaredTypeTemplateName(Scope
*S
, TemplateTy
&ParsedName
,
4145 TemplateNameKind
&TNK
,
4146 SourceLocation NameLoc
,
4147 IdentifierInfo
*&II
) {
4148 assert(TNK
== TNK_Undeclared_template
&& "not an undeclared template name");
4150 TemplateName Name
= ParsedName
.get();
4151 auto *ATN
= Name
.getAsAssumedTemplateName();
4152 assert(ATN
&& "not an assumed template name");
4153 II
= ATN
->getDeclName().getAsIdentifierInfo();
4155 if (!resolveAssumedTemplateNameAsType(S
, Name
, NameLoc
, /*Diagnose*/false)) {
4156 // Resolved to a type template name.
4157 ParsedName
= TemplateTy::make(Name
);
4158 TNK
= TNK_Type_template
;
4162 bool Sema::resolveAssumedTemplateNameAsType(Scope
*S
, TemplateName
&Name
,
4163 SourceLocation NameLoc
,
4165 // We assumed this undeclared identifier to be an (ADL-only) function
4166 // template name, but it was used in a context where a type was required.
4167 // Try to typo-correct it now.
4168 AssumedTemplateStorage
*ATN
= Name
.getAsAssumedTemplateName();
4169 assert(ATN
&& "not an assumed template name");
4171 LookupResult
R(*this, ATN
->getDeclName(), NameLoc
, LookupOrdinaryName
);
4172 struct CandidateCallback
: CorrectionCandidateCallback
{
4173 bool ValidateCandidate(const TypoCorrection
&TC
) override
{
4174 return TC
.getCorrectionDecl() &&
4175 getAsTypeTemplateDecl(TC
.getCorrectionDecl());
4177 std::unique_ptr
<CorrectionCandidateCallback
> clone() override
{
4178 return std::make_unique
<CandidateCallback
>(*this);
4182 TypoCorrection Corrected
=
4183 CorrectTypo(R
.getLookupNameInfo(), R
.getLookupKind(), S
, nullptr,
4184 FilterCCC
, CTK_ErrorRecovery
);
4185 if (Corrected
&& Corrected
.getFoundDecl()) {
4186 diagnoseTypo(Corrected
, PDiag(diag::err_no_template_suggest
)
4187 << ATN
->getDeclName());
4188 Name
= TemplateName(Corrected
.getCorrectionDeclAs
<TemplateDecl
>());
4193 Diag(R
.getNameLoc(), diag::err_no_template
) << R
.getLookupName();
4197 TypeResult
Sema::ActOnTemplateIdType(
4198 Scope
*S
, CXXScopeSpec
&SS
, SourceLocation TemplateKWLoc
,
4199 TemplateTy TemplateD
, IdentifierInfo
*TemplateII
,
4200 SourceLocation TemplateIILoc
, SourceLocation LAngleLoc
,
4201 ASTTemplateArgsPtr TemplateArgsIn
, SourceLocation RAngleLoc
,
4202 bool IsCtorOrDtorName
, bool IsClassName
,
4203 ImplicitTypenameContext AllowImplicitTypename
) {
4207 if (!IsCtorOrDtorName
&& !IsClassName
&& SS
.isSet()) {
4208 DeclContext
*LookupCtx
= computeDeclContext(SS
, /*EnteringContext*/false);
4210 // C++ [temp.res]p3:
4211 // A qualified-id that refers to a type and in which the
4212 // nested-name-specifier depends on a template-parameter (14.6.2)
4213 // shall be prefixed by the keyword typename to indicate that the
4214 // qualified-id denotes a type, forming an
4215 // elaborated-type-specifier (7.1.5.3).
4216 if (!LookupCtx
&& isDependentScopeSpecifier(SS
)) {
4217 // C++2a relaxes some of those restrictions in [temp.res]p5.
4218 if (AllowImplicitTypename
== ImplicitTypenameContext::Yes
) {
4219 if (getLangOpts().CPlusPlus20
)
4220 Diag(SS
.getBeginLoc(), diag::warn_cxx17_compat_implicit_typename
);
4222 Diag(SS
.getBeginLoc(), diag::ext_implicit_typename
)
4223 << SS
.getScopeRep() << TemplateII
->getName()
4224 << FixItHint::CreateInsertion(SS
.getBeginLoc(), "typename ");
4226 Diag(SS
.getBeginLoc(), diag::err_typename_missing_template
)
4227 << SS
.getScopeRep() << TemplateII
->getName();
4229 // FIXME: This is not quite correct recovery as we don't transform SS
4230 // into the corresponding dependent form (and we don't diagnose missing
4231 // 'template' keywords within SS as a result).
4232 return ActOnTypenameType(nullptr, SourceLocation(), SS
, TemplateKWLoc
,
4233 TemplateD
, TemplateII
, TemplateIILoc
, LAngleLoc
,
4234 TemplateArgsIn
, RAngleLoc
);
4237 // Per C++ [class.qual]p2, if the template-id was an injected-class-name,
4238 // it's not actually allowed to be used as a type in most cases. Because
4239 // we annotate it before we know whether it's valid, we have to check for
4241 auto *LookupRD
= dyn_cast_or_null
<CXXRecordDecl
>(LookupCtx
);
4242 if (LookupRD
&& LookupRD
->getIdentifier() == TemplateII
) {
4244 TemplateKWLoc
.isInvalid()
4245 ? diag::err_out_of_line_qualified_id_type_names_constructor
4246 : diag::ext_out_of_line_qualified_id_type_names_constructor
)
4247 << TemplateII
<< 0 /*injected-class-name used as template name*/
4248 << 1 /*if any keyword was present, it was 'template'*/;
4252 TemplateName Template
= TemplateD
.get();
4253 if (Template
.getAsAssumedTemplateName() &&
4254 resolveAssumedTemplateNameAsType(S
, Template
, TemplateIILoc
))
4257 // Translate the parser's template argument list in our AST format.
4258 TemplateArgumentListInfo
TemplateArgs(LAngleLoc
, RAngleLoc
);
4259 translateTemplateArguments(TemplateArgsIn
, TemplateArgs
);
4261 if (DependentTemplateName
*DTN
= Template
.getAsDependentTemplateName()) {
4262 assert(SS
.getScopeRep() == DTN
->getQualifier());
4263 QualType T
= Context
.getDependentTemplateSpecializationType(
4264 ElaboratedTypeKeyword::None
, DTN
->getQualifier(), DTN
->getIdentifier(),
4265 TemplateArgs
.arguments());
4266 // Build type-source information.
4268 DependentTemplateSpecializationTypeLoc SpecTL
4269 = TLB
.push
<DependentTemplateSpecializationTypeLoc
>(T
);
4270 SpecTL
.setElaboratedKeywordLoc(SourceLocation());
4271 SpecTL
.setQualifierLoc(SS
.getWithLocInContext(Context
));
4272 SpecTL
.setTemplateKeywordLoc(TemplateKWLoc
);
4273 SpecTL
.setTemplateNameLoc(TemplateIILoc
);
4274 SpecTL
.setLAngleLoc(LAngleLoc
);
4275 SpecTL
.setRAngleLoc(RAngleLoc
);
4276 for (unsigned I
= 0, N
= SpecTL
.getNumArgs(); I
!= N
; ++I
)
4277 SpecTL
.setArgLocInfo(I
, TemplateArgs
[I
].getLocInfo());
4278 return CreateParsedType(T
, TLB
.getTypeSourceInfo(Context
, T
));
4281 QualType SpecTy
= CheckTemplateIdType(Template
, TemplateIILoc
, TemplateArgs
);
4282 if (SpecTy
.isNull())
4285 // Build type-source information.
4287 TemplateSpecializationTypeLoc SpecTL
=
4288 TLB
.push
<TemplateSpecializationTypeLoc
>(SpecTy
);
4289 SpecTL
.setTemplateKeywordLoc(TemplateKWLoc
);
4290 SpecTL
.setTemplateNameLoc(TemplateIILoc
);
4291 SpecTL
.setLAngleLoc(LAngleLoc
);
4292 SpecTL
.setRAngleLoc(RAngleLoc
);
4293 for (unsigned i
= 0, e
= SpecTL
.getNumArgs(); i
!= e
; ++i
)
4294 SpecTL
.setArgLocInfo(i
, TemplateArgs
[i
].getLocInfo());
4296 // Create an elaborated-type-specifier containing the nested-name-specifier.
4298 getElaboratedType(ElaboratedTypeKeyword::None
,
4299 !IsCtorOrDtorName
? SS
: CXXScopeSpec(), SpecTy
);
4300 ElaboratedTypeLoc ElabTL
= TLB
.push
<ElaboratedTypeLoc
>(ElTy
);
4301 ElabTL
.setElaboratedKeywordLoc(SourceLocation());
4302 if (!ElabTL
.isEmpty())
4303 ElabTL
.setQualifierLoc(SS
.getWithLocInContext(Context
));
4304 return CreateParsedType(ElTy
, TLB
.getTypeSourceInfo(Context
, ElTy
));
4307 TypeResult
Sema::ActOnTagTemplateIdType(TagUseKind TUK
,
4308 TypeSpecifierType TagSpec
,
4309 SourceLocation TagLoc
,
4311 SourceLocation TemplateKWLoc
,
4312 TemplateTy TemplateD
,
4313 SourceLocation TemplateLoc
,
4314 SourceLocation LAngleLoc
,
4315 ASTTemplateArgsPtr TemplateArgsIn
,
4316 SourceLocation RAngleLoc
) {
4318 return TypeResult(true);
4320 TemplateName Template
= TemplateD
.get();
4322 // Translate the parser's template argument list in our AST format.
4323 TemplateArgumentListInfo
TemplateArgs(LAngleLoc
, RAngleLoc
);
4324 translateTemplateArguments(TemplateArgsIn
, TemplateArgs
);
4326 // Determine the tag kind
4327 TagTypeKind TagKind
= TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec
);
4328 ElaboratedTypeKeyword Keyword
4329 = TypeWithKeyword::getKeywordForTagTypeKind(TagKind
);
4331 if (DependentTemplateName
*DTN
= Template
.getAsDependentTemplateName()) {
4332 assert(SS
.getScopeRep() == DTN
->getQualifier());
4333 QualType T
= Context
.getDependentTemplateSpecializationType(
4334 Keyword
, DTN
->getQualifier(), DTN
->getIdentifier(),
4335 TemplateArgs
.arguments());
4337 // Build type-source information.
4339 DependentTemplateSpecializationTypeLoc SpecTL
4340 = TLB
.push
<DependentTemplateSpecializationTypeLoc
>(T
);
4341 SpecTL
.setElaboratedKeywordLoc(TagLoc
);
4342 SpecTL
.setQualifierLoc(SS
.getWithLocInContext(Context
));
4343 SpecTL
.setTemplateKeywordLoc(TemplateKWLoc
);
4344 SpecTL
.setTemplateNameLoc(TemplateLoc
);
4345 SpecTL
.setLAngleLoc(LAngleLoc
);
4346 SpecTL
.setRAngleLoc(RAngleLoc
);
4347 for (unsigned I
= 0, N
= SpecTL
.getNumArgs(); I
!= N
; ++I
)
4348 SpecTL
.setArgLocInfo(I
, TemplateArgs
[I
].getLocInfo());
4349 return CreateParsedType(T
, TLB
.getTypeSourceInfo(Context
, T
));
4352 if (TypeAliasTemplateDecl
*TAT
=
4353 dyn_cast_or_null
<TypeAliasTemplateDecl
>(Template
.getAsTemplateDecl())) {
4354 // C++0x [dcl.type.elab]p2:
4355 // If the identifier resolves to a typedef-name or the simple-template-id
4356 // resolves to an alias template specialization, the
4357 // elaborated-type-specifier is ill-formed.
4358 Diag(TemplateLoc
, diag::err_tag_reference_non_tag
)
4359 << TAT
<< NTK_TypeAliasTemplate
<< llvm::to_underlying(TagKind
);
4360 Diag(TAT
->getLocation(), diag::note_declared_at
);
4363 QualType Result
= CheckTemplateIdType(Template
, TemplateLoc
, TemplateArgs
);
4364 if (Result
.isNull())
4365 return TypeResult(true);
4367 // Check the tag kind
4368 if (const RecordType
*RT
= Result
->getAs
<RecordType
>()) {
4369 RecordDecl
*D
= RT
->getDecl();
4371 IdentifierInfo
*Id
= D
->getIdentifier();
4372 assert(Id
&& "templated class must have an identifier");
4374 if (!isAcceptableTagRedeclaration(D
, TagKind
, TUK
== TUK_Definition
,
4376 Diag(TagLoc
, diag::err_use_with_wrong_tag
)
4378 << FixItHint::CreateReplacement(SourceRange(TagLoc
), D
->getKindName());
4379 Diag(D
->getLocation(), diag::note_previous_use
);
4383 // Provide source-location information for the template specialization.
4385 TemplateSpecializationTypeLoc SpecTL
4386 = TLB
.push
<TemplateSpecializationTypeLoc
>(Result
);
4387 SpecTL
.setTemplateKeywordLoc(TemplateKWLoc
);
4388 SpecTL
.setTemplateNameLoc(TemplateLoc
);
4389 SpecTL
.setLAngleLoc(LAngleLoc
);
4390 SpecTL
.setRAngleLoc(RAngleLoc
);
4391 for (unsigned i
= 0, e
= SpecTL
.getNumArgs(); i
!= e
; ++i
)
4392 SpecTL
.setArgLocInfo(i
, TemplateArgs
[i
].getLocInfo());
4394 // Construct an elaborated type containing the nested-name-specifier (if any)
4396 Result
= Context
.getElaboratedType(Keyword
, SS
.getScopeRep(), Result
);
4397 ElaboratedTypeLoc ElabTL
= TLB
.push
<ElaboratedTypeLoc
>(Result
);
4398 ElabTL
.setElaboratedKeywordLoc(TagLoc
);
4399 ElabTL
.setQualifierLoc(SS
.getWithLocInContext(Context
));
4400 return CreateParsedType(Result
, TLB
.getTypeSourceInfo(Context
, Result
));
4403 static bool CheckTemplateSpecializationScope(Sema
&S
, NamedDecl
*Specialized
,
4404 NamedDecl
*PrevDecl
,
4406 bool IsPartialSpecialization
);
4408 static TemplateSpecializationKind
getTemplateSpecializationKind(Decl
*D
);
4410 static bool isTemplateArgumentTemplateParameter(
4411 const TemplateArgument
&Arg
, unsigned Depth
, unsigned Index
) {
4412 switch (Arg
.getKind()) {
4413 case TemplateArgument::Null
:
4414 case TemplateArgument::NullPtr
:
4415 case TemplateArgument::Integral
:
4416 case TemplateArgument::Declaration
:
4417 case TemplateArgument::Pack
:
4418 case TemplateArgument::TemplateExpansion
:
4421 case TemplateArgument::Type
: {
4422 QualType Type
= Arg
.getAsType();
4423 const TemplateTypeParmType
*TPT
=
4424 Arg
.getAsType()->getAs
<TemplateTypeParmType
>();
4425 return TPT
&& !Type
.hasQualifiers() &&
4426 TPT
->getDepth() == Depth
&& TPT
->getIndex() == Index
;
4429 case TemplateArgument::Expression
: {
4430 DeclRefExpr
*DRE
= dyn_cast
<DeclRefExpr
>(Arg
.getAsExpr());
4431 if (!DRE
|| !DRE
->getDecl())
4433 const NonTypeTemplateParmDecl
*NTTP
=
4434 dyn_cast
<NonTypeTemplateParmDecl
>(DRE
->getDecl());
4435 return NTTP
&& NTTP
->getDepth() == Depth
&& NTTP
->getIndex() == Index
;
4438 case TemplateArgument::Template
:
4439 const TemplateTemplateParmDecl
*TTP
=
4440 dyn_cast_or_null
<TemplateTemplateParmDecl
>(
4441 Arg
.getAsTemplateOrTemplatePattern().getAsTemplateDecl());
4442 return TTP
&& TTP
->getDepth() == Depth
&& TTP
->getIndex() == Index
;
4444 llvm_unreachable("unexpected kind of template argument");
4447 static bool isSameAsPrimaryTemplate(TemplateParameterList
*Params
,
4448 ArrayRef
<TemplateArgument
> Args
) {
4449 if (Params
->size() != Args
.size())
4452 unsigned Depth
= Params
->getDepth();
4454 for (unsigned I
= 0, N
= Args
.size(); I
!= N
; ++I
) {
4455 TemplateArgument Arg
= Args
[I
];
4457 // If the parameter is a pack expansion, the argument must be a pack
4458 // whose only element is a pack expansion.
4459 if (Params
->getParam(I
)->isParameterPack()) {
4460 if (Arg
.getKind() != TemplateArgument::Pack
|| Arg
.pack_size() != 1 ||
4461 !Arg
.pack_begin()->isPackExpansion())
4463 Arg
= Arg
.pack_begin()->getPackExpansionPattern();
4466 if (!isTemplateArgumentTemplateParameter(Arg
, Depth
, I
))
4473 template<typename PartialSpecDecl
>
4474 static void checkMoreSpecializedThanPrimary(Sema
&S
, PartialSpecDecl
*Partial
) {
4475 if (Partial
->getDeclContext()->isDependentContext())
4478 // FIXME: Get the TDK from deduction in order to provide better diagnostics
4479 // for non-substitution-failure issues?
4480 TemplateDeductionInfo
Info(Partial
->getLocation());
4481 if (S
.isMoreSpecializedThanPrimary(Partial
, Info
))
4484 auto *Template
= Partial
->getSpecializedTemplate();
4485 S
.Diag(Partial
->getLocation(),
4486 diag::ext_partial_spec_not_more_specialized_than_primary
)
4487 << isa
<VarTemplateDecl
>(Template
);
4489 if (Info
.hasSFINAEDiagnostic()) {
4490 PartialDiagnosticAt Diag
= {SourceLocation(),
4491 PartialDiagnostic::NullDiagnostic()};
4492 Info
.takeSFINAEDiagnostic(Diag
);
4493 SmallString
<128> SFINAEArgString
;
4494 Diag
.second
.EmitToString(S
.getDiagnostics(), SFINAEArgString
);
4496 diag::note_partial_spec_not_more_specialized_than_primary
)
4500 S
.NoteTemplateLocation(*Template
);
4501 SmallVector
<const Expr
*, 3> PartialAC
, TemplateAC
;
4502 Template
->getAssociatedConstraints(TemplateAC
);
4503 Partial
->getAssociatedConstraints(PartialAC
);
4504 S
.MaybeEmitAmbiguousAtomicConstraintsDiagnostic(Partial
, PartialAC
, Template
,
4509 noteNonDeducibleParameters(Sema
&S
, TemplateParameterList
*TemplateParams
,
4510 const llvm::SmallBitVector
&DeducibleParams
) {
4511 for (unsigned I
= 0, N
= DeducibleParams
.size(); I
!= N
; ++I
) {
4512 if (!DeducibleParams
[I
]) {
4513 NamedDecl
*Param
= TemplateParams
->getParam(I
);
4514 if (Param
->getDeclName())
4515 S
.Diag(Param
->getLocation(), diag::note_non_deducible_parameter
)
4516 << Param
->getDeclName();
4518 S
.Diag(Param
->getLocation(), diag::note_non_deducible_parameter
)
4525 template<typename PartialSpecDecl
>
4526 static void checkTemplatePartialSpecialization(Sema
&S
,
4527 PartialSpecDecl
*Partial
) {
4528 // C++1z [temp.class.spec]p8: (DR1495)
4529 // - The specialization shall be more specialized than the primary
4530 // template (14.5.5.2).
4531 checkMoreSpecializedThanPrimary(S
, Partial
);
4533 // C++ [temp.class.spec]p8: (DR1315)
4534 // - Each template-parameter shall appear at least once in the
4535 // template-id outside a non-deduced context.
4536 // C++1z [temp.class.spec.match]p3 (P0127R2)
4537 // If the template arguments of a partial specialization cannot be
4538 // deduced because of the structure of its template-parameter-list
4539 // and the template-id, the program is ill-formed.
4540 auto *TemplateParams
= Partial
->getTemplateParameters();
4541 llvm::SmallBitVector
DeducibleParams(TemplateParams
->size());
4542 S
.MarkUsedTemplateParameters(Partial
->getTemplateArgs(), true,
4543 TemplateParams
->getDepth(), DeducibleParams
);
4545 if (!DeducibleParams
.all()) {
4546 unsigned NumNonDeducible
= DeducibleParams
.size() - DeducibleParams
.count();
4547 S
.Diag(Partial
->getLocation(), diag::ext_partial_specs_not_deducible
)
4548 << isa
<VarTemplatePartialSpecializationDecl
>(Partial
)
4549 << (NumNonDeducible
> 1)
4550 << SourceRange(Partial
->getLocation(),
4551 Partial
->getTemplateArgsAsWritten()->RAngleLoc
);
4552 noteNonDeducibleParameters(S
, TemplateParams
, DeducibleParams
);
4556 void Sema::CheckTemplatePartialSpecialization(
4557 ClassTemplatePartialSpecializationDecl
*Partial
) {
4558 checkTemplatePartialSpecialization(*this, Partial
);
4561 void Sema::CheckTemplatePartialSpecialization(
4562 VarTemplatePartialSpecializationDecl
*Partial
) {
4563 checkTemplatePartialSpecialization(*this, Partial
);
4566 void Sema::CheckDeductionGuideTemplate(FunctionTemplateDecl
*TD
) {
4567 // C++1z [temp.param]p11:
4568 // A template parameter of a deduction guide template that does not have a
4569 // default-argument shall be deducible from the parameter-type-list of the
4570 // deduction guide template.
4571 auto *TemplateParams
= TD
->getTemplateParameters();
4572 llvm::SmallBitVector
DeducibleParams(TemplateParams
->size());
4573 MarkDeducedTemplateParameters(TD
, DeducibleParams
);
4574 for (unsigned I
= 0; I
!= TemplateParams
->size(); ++I
) {
4575 // A parameter pack is deducible (to an empty pack).
4576 auto *Param
= TemplateParams
->getParam(I
);
4577 if (Param
->isParameterPack() || hasVisibleDefaultArgument(Param
))
4578 DeducibleParams
[I
] = true;
4581 if (!DeducibleParams
.all()) {
4582 unsigned NumNonDeducible
= DeducibleParams
.size() - DeducibleParams
.count();
4583 Diag(TD
->getLocation(), diag::err_deduction_guide_template_not_deducible
)
4584 << (NumNonDeducible
> 1);
4585 noteNonDeducibleParameters(*this, TemplateParams
, DeducibleParams
);
4589 DeclResult
Sema::ActOnVarTemplateSpecialization(
4590 Scope
*S
, Declarator
&D
, TypeSourceInfo
*DI
, SourceLocation TemplateKWLoc
,
4591 TemplateParameterList
*TemplateParams
, StorageClass SC
,
4592 bool IsPartialSpecialization
) {
4593 // D must be variable template id.
4594 assert(D
.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
&&
4595 "Variable template specialization is declared with a template id.");
4597 TemplateIdAnnotation
*TemplateId
= D
.getName().TemplateId
;
4598 TemplateArgumentListInfo TemplateArgs
=
4599 makeTemplateArgumentListInfo(*this, *TemplateId
);
4600 SourceLocation TemplateNameLoc
= D
.getIdentifierLoc();
4601 SourceLocation LAngleLoc
= TemplateId
->LAngleLoc
;
4602 SourceLocation RAngleLoc
= TemplateId
->RAngleLoc
;
4604 TemplateName Name
= TemplateId
->Template
.get();
4606 // The template-id must name a variable template.
4607 VarTemplateDecl
*VarTemplate
=
4608 dyn_cast_or_null
<VarTemplateDecl
>(Name
.getAsTemplateDecl());
4610 NamedDecl
*FnTemplate
;
4611 if (auto *OTS
= Name
.getAsOverloadedTemplate())
4612 FnTemplate
= *OTS
->begin();
4614 FnTemplate
= dyn_cast_or_null
<FunctionTemplateDecl
>(Name
.getAsTemplateDecl());
4616 return Diag(D
.getIdentifierLoc(), diag::err_var_spec_no_template_but_method
)
4617 << FnTemplate
->getDeclName();
4618 return Diag(D
.getIdentifierLoc(), diag::err_var_spec_no_template
)
4619 << IsPartialSpecialization
;
4622 // Check for unexpanded parameter packs in any of the template arguments.
4623 for (unsigned I
= 0, N
= TemplateArgs
.size(); I
!= N
; ++I
)
4624 if (DiagnoseUnexpandedParameterPack(TemplateArgs
[I
],
4625 IsPartialSpecialization
4626 ? UPPC_PartialSpecialization
4627 : UPPC_ExplicitSpecialization
))
4630 // Check that the template argument list is well-formed for this
4632 SmallVector
<TemplateArgument
, 4> SugaredConverted
, CanonicalConverted
;
4633 if (CheckTemplateArgumentList(VarTemplate
, TemplateNameLoc
, TemplateArgs
,
4634 false, SugaredConverted
, CanonicalConverted
,
4635 /*UpdateArgsWithConversions=*/true))
4638 // Find the variable template (partial) specialization declaration that
4639 // corresponds to these arguments.
4640 if (IsPartialSpecialization
) {
4641 if (CheckTemplatePartialSpecializationArgs(TemplateNameLoc
, VarTemplate
,
4642 TemplateArgs
.size(),
4643 CanonicalConverted
))
4646 // FIXME: Move these checks to CheckTemplatePartialSpecializationArgs so we
4647 // also do them during instantiation.
4648 if (!Name
.isDependent() &&
4649 !TemplateSpecializationType::anyDependentTemplateArguments(
4650 TemplateArgs
, CanonicalConverted
)) {
4651 Diag(TemplateNameLoc
, diag::err_partial_spec_fully_specialized
)
4652 << VarTemplate
->getDeclName();
4653 IsPartialSpecialization
= false;
4656 if (isSameAsPrimaryTemplate(VarTemplate
->getTemplateParameters(),
4657 CanonicalConverted
) &&
4658 (!Context
.getLangOpts().CPlusPlus20
||
4659 !TemplateParams
->hasAssociatedConstraints())) {
4660 // C++ [temp.class.spec]p9b3:
4662 // -- The argument list of the specialization shall not be identical
4663 // to the implicit argument list of the primary template.
4664 Diag(TemplateNameLoc
, diag::err_partial_spec_args_match_primary_template
)
4665 << /*variable template*/ 1
4666 << /*is definition*/(SC
!= SC_Extern
&& !CurContext
->isRecord())
4667 << FixItHint::CreateRemoval(SourceRange(LAngleLoc
, RAngleLoc
));
4668 // FIXME: Recover from this by treating the declaration as a redeclaration
4669 // of the primary template.
4674 void *InsertPos
= nullptr;
4675 VarTemplateSpecializationDecl
*PrevDecl
= nullptr;
4677 if (IsPartialSpecialization
)
4678 PrevDecl
= VarTemplate
->findPartialSpecialization(
4679 CanonicalConverted
, TemplateParams
, InsertPos
);
4681 PrevDecl
= VarTemplate
->findSpecialization(CanonicalConverted
, InsertPos
);
4683 VarTemplateSpecializationDecl
*Specialization
= nullptr;
4685 // Check whether we can declare a variable template specialization in
4686 // the current scope.
4687 if (CheckTemplateSpecializationScope(*this, VarTemplate
, PrevDecl
,
4689 IsPartialSpecialization
))
4692 if (PrevDecl
&& PrevDecl
->getSpecializationKind() == TSK_Undeclared
) {
4693 // Since the only prior variable template specialization with these
4694 // arguments was referenced but not declared, reuse that
4695 // declaration node as our own, updating its source location and
4696 // the list of outer template parameters to reflect our new declaration.
4697 Specialization
= PrevDecl
;
4698 Specialization
->setLocation(TemplateNameLoc
);
4700 } else if (IsPartialSpecialization
) {
4701 // Create a new class template partial specialization declaration node.
4702 VarTemplatePartialSpecializationDecl
*PrevPartial
=
4703 cast_or_null
<VarTemplatePartialSpecializationDecl
>(PrevDecl
);
4704 VarTemplatePartialSpecializationDecl
*Partial
=
4705 VarTemplatePartialSpecializationDecl::Create(
4706 Context
, VarTemplate
->getDeclContext(), TemplateKWLoc
,
4707 TemplateNameLoc
, TemplateParams
, VarTemplate
, DI
->getType(), DI
, SC
,
4708 CanonicalConverted
, TemplateArgs
);
4711 VarTemplate
->AddPartialSpecialization(Partial
, InsertPos
);
4712 Specialization
= Partial
;
4714 // If we are providing an explicit specialization of a member variable
4715 // template specialization, make a note of that.
4716 if (PrevPartial
&& PrevPartial
->getInstantiatedFromMember())
4717 PrevPartial
->setMemberSpecialization();
4719 CheckTemplatePartialSpecialization(Partial
);
4721 // Create a new class template specialization declaration node for
4722 // this explicit specialization or friend declaration.
4723 Specialization
= VarTemplateSpecializationDecl::Create(
4724 Context
, VarTemplate
->getDeclContext(), TemplateKWLoc
, TemplateNameLoc
,
4725 VarTemplate
, DI
->getType(), DI
, SC
, CanonicalConverted
);
4726 Specialization
->setTemplateArgsInfo(TemplateArgs
);
4729 VarTemplate
->AddSpecialization(Specialization
, InsertPos
);
4732 // C++ [temp.expl.spec]p6:
4733 // If a template, a member template or the member of a class template is
4734 // explicitly specialized then that specialization shall be declared
4735 // before the first use of that specialization that would cause an implicit
4736 // instantiation to take place, in every translation unit in which such a
4737 // use occurs; no diagnostic is required.
4738 if (PrevDecl
&& PrevDecl
->getPointOfInstantiation().isValid()) {
4740 for (Decl
*Prev
= PrevDecl
; Prev
; Prev
= Prev
->getPreviousDecl()) {
4741 // Is there any previous explicit specialization declaration?
4742 if (getTemplateSpecializationKind(Prev
) == TSK_ExplicitSpecialization
) {
4749 SourceRange
Range(TemplateNameLoc
, RAngleLoc
);
4750 Diag(TemplateNameLoc
, diag::err_specialization_after_instantiation
)
4753 Diag(PrevDecl
->getPointOfInstantiation(),
4754 diag::note_instantiation_required_here
)
4755 << (PrevDecl
->getTemplateSpecializationKind() !=
4756 TSK_ImplicitInstantiation
);
4761 Specialization
->setTemplateKeywordLoc(TemplateKWLoc
);
4762 Specialization
->setLexicalDeclContext(CurContext
);
4764 // Add the specialization into its lexical context, so that it can
4765 // be seen when iterating through the list of declarations in that
4766 // context. However, specializations are not found by name lookup.
4767 CurContext
->addDecl(Specialization
);
4769 // Note that this is an explicit specialization.
4770 Specialization
->setSpecializationKind(TSK_ExplicitSpecialization
);
4773 // Check that this isn't a redefinition of this specialization,
4774 // merging with previous declarations.
4775 LookupResult
PrevSpec(*this, GetNameForDeclarator(D
), LookupOrdinaryName
,
4776 forRedeclarationInCurContext());
4777 PrevSpec
.addDecl(PrevDecl
);
4778 D
.setRedeclaration(CheckVariableDeclaration(Specialization
, PrevSpec
));
4779 } else if (Specialization
->isStaticDataMember() &&
4780 Specialization
->isOutOfLine()) {
4781 Specialization
->setAccess(VarTemplate
->getAccess());
4784 return Specialization
;
4788 /// A partial specialization whose template arguments have matched
4789 /// a given template-id.
4790 struct PartialSpecMatchResult
{
4791 VarTemplatePartialSpecializationDecl
*Partial
;
4792 TemplateArgumentList
*Args
;
4794 } // end anonymous namespace
4797 Sema::CheckVarTemplateId(VarTemplateDecl
*Template
, SourceLocation TemplateLoc
,
4798 SourceLocation TemplateNameLoc
,
4799 const TemplateArgumentListInfo
&TemplateArgs
) {
4800 assert(Template
&& "A variable template id without template?");
4802 // Check that the template argument list is well-formed for this template.
4803 SmallVector
<TemplateArgument
, 4> SugaredConverted
, CanonicalConverted
;
4804 if (CheckTemplateArgumentList(
4805 Template
, TemplateNameLoc
,
4806 const_cast<TemplateArgumentListInfo
&>(TemplateArgs
), false,
4807 SugaredConverted
, CanonicalConverted
,
4808 /*UpdateArgsWithConversions=*/true))
4811 // Produce a placeholder value if the specialization is dependent.
4812 if (Template
->getDeclContext()->isDependentContext() ||
4813 TemplateSpecializationType::anyDependentTemplateArguments(
4814 TemplateArgs
, CanonicalConverted
))
4815 return DeclResult();
4817 // Find the variable template specialization declaration that
4818 // corresponds to these arguments.
4819 void *InsertPos
= nullptr;
4820 if (VarTemplateSpecializationDecl
*Spec
=
4821 Template
->findSpecialization(CanonicalConverted
, InsertPos
)) {
4822 checkSpecializationReachability(TemplateNameLoc
, Spec
);
4823 // If we already have a variable template specialization, return it.
4827 // This is the first time we have referenced this variable template
4828 // specialization. Create the canonical declaration and add it to
4829 // the set of specializations, based on the closest partial specialization
4830 // that it represents. That is,
4831 VarDecl
*InstantiationPattern
= Template
->getTemplatedDecl();
4832 TemplateArgumentList
TemplateArgList(TemplateArgumentList::OnStack
,
4833 CanonicalConverted
);
4834 TemplateArgumentList
*InstantiationArgs
= &TemplateArgList
;
4835 bool AmbiguousPartialSpec
= false;
4836 typedef PartialSpecMatchResult MatchResult
;
4837 SmallVector
<MatchResult
, 4> Matched
;
4838 SourceLocation PointOfInstantiation
= TemplateNameLoc
;
4839 TemplateSpecCandidateSet
FailedCandidates(PointOfInstantiation
,
4840 /*ForTakingAddress=*/false);
4842 // 1. Attempt to find the closest partial specialization that this
4843 // specializes, if any.
4844 // TODO: Unify with InstantiateClassTemplateSpecialization()?
4845 // Perhaps better after unification of DeduceTemplateArguments() and
4846 // getMoreSpecializedPartialSpecialization().
4847 SmallVector
<VarTemplatePartialSpecializationDecl
*, 4> PartialSpecs
;
4848 Template
->getPartialSpecializations(PartialSpecs
);
4850 for (unsigned I
= 0, N
= PartialSpecs
.size(); I
!= N
; ++I
) {
4851 VarTemplatePartialSpecializationDecl
*Partial
= PartialSpecs
[I
];
4852 TemplateDeductionInfo
Info(FailedCandidates
.getLocation());
4854 if (TemplateDeductionResult Result
=
4855 DeduceTemplateArguments(Partial
, TemplateArgList
, Info
)) {
4856 // Store the failed-deduction information for use in diagnostics, later.
4857 // TODO: Actually use the failed-deduction info?
4858 FailedCandidates
.addCandidate().set(
4859 DeclAccessPair::make(Template
, AS_public
), Partial
,
4860 MakeDeductionFailureInfo(Context
, Result
, Info
));
4863 Matched
.push_back(PartialSpecMatchResult());
4864 Matched
.back().Partial
= Partial
;
4865 Matched
.back().Args
= Info
.takeCanonical();
4869 if (Matched
.size() >= 1) {
4870 SmallVector
<MatchResult
, 4>::iterator Best
= Matched
.begin();
4871 if (Matched
.size() == 1) {
4872 // -- If exactly one matching specialization is found, the
4873 // instantiation is generated from that specialization.
4874 // We don't need to do anything for this.
4876 // -- If more than one matching specialization is found, the
4877 // partial order rules (14.5.4.2) are used to determine
4878 // whether one of the specializations is more specialized
4879 // than the others. If none of the specializations is more
4880 // specialized than all of the other matching
4881 // specializations, then the use of the variable template is
4882 // ambiguous and the program is ill-formed.
4883 for (SmallVector
<MatchResult
, 4>::iterator P
= Best
+ 1,
4884 PEnd
= Matched
.end();
4886 if (getMoreSpecializedPartialSpecialization(P
->Partial
, Best
->Partial
,
4887 PointOfInstantiation
) ==
4892 // Determine if the best partial specialization is more specialized than
4894 for (SmallVector
<MatchResult
, 4>::iterator P
= Matched
.begin(),
4895 PEnd
= Matched
.end();
4897 if (P
!= Best
&& getMoreSpecializedPartialSpecialization(
4898 P
->Partial
, Best
->Partial
,
4899 PointOfInstantiation
) != Best
->Partial
) {
4900 AmbiguousPartialSpec
= true;
4906 // Instantiate using the best variable template partial specialization.
4907 InstantiationPattern
= Best
->Partial
;
4908 InstantiationArgs
= Best
->Args
;
4910 // -- If no match is found, the instantiation is generated
4911 // from the primary template.
4912 // InstantiationPattern = Template->getTemplatedDecl();
4915 // 2. Create the canonical declaration.
4916 // Note that we do not instantiate a definition until we see an odr-use
4917 // in DoMarkVarDeclReferenced().
4918 // FIXME: LateAttrs et al.?
4919 VarTemplateSpecializationDecl
*Decl
= BuildVarTemplateInstantiation(
4920 Template
, InstantiationPattern
, *InstantiationArgs
, TemplateArgs
,
4921 CanonicalConverted
, TemplateNameLoc
/*, LateAttrs, StartingScope*/);
4925 if (AmbiguousPartialSpec
) {
4926 // Partial ordering did not produce a clear winner. Complain.
4927 Decl
->setInvalidDecl();
4928 Diag(PointOfInstantiation
, diag::err_partial_spec_ordering_ambiguous
)
4931 // Print the matching partial specializations.
4932 for (MatchResult P
: Matched
)
4933 Diag(P
.Partial
->getLocation(), diag::note_partial_spec_match
)
4934 << getTemplateArgumentBindingsText(P
.Partial
->getTemplateParameters(),
4939 if (VarTemplatePartialSpecializationDecl
*D
=
4940 dyn_cast
<VarTemplatePartialSpecializationDecl
>(InstantiationPattern
))
4941 Decl
->setInstantiationOf(D
, InstantiationArgs
);
4943 checkSpecializationReachability(TemplateNameLoc
, Decl
);
4945 assert(Decl
&& "No variable template specialization?");
4950 Sema::CheckVarTemplateId(const CXXScopeSpec
&SS
,
4951 const DeclarationNameInfo
&NameInfo
,
4952 VarTemplateDecl
*Template
, SourceLocation TemplateLoc
,
4953 const TemplateArgumentListInfo
*TemplateArgs
) {
4955 DeclResult Decl
= CheckVarTemplateId(Template
, TemplateLoc
, NameInfo
.getLoc(),
4957 if (Decl
.isInvalid())
4961 return ExprResult();
4963 VarDecl
*Var
= cast
<VarDecl
>(Decl
.get());
4964 if (!Var
->getTemplateSpecializationKind())
4965 Var
->setTemplateSpecializationKind(TSK_ImplicitInstantiation
,
4968 // Build an ordinary singleton decl ref.
4969 return BuildDeclarationNameExpr(SS
, NameInfo
, Var
,
4970 /*FoundD=*/nullptr, TemplateArgs
);
4973 void Sema::diagnoseMissingTemplateArguments(TemplateName Name
,
4974 SourceLocation Loc
) {
4975 Diag(Loc
, diag::err_template_missing_args
)
4976 << (int)getTemplateNameKindForDiagnostics(Name
) << Name
;
4977 if (TemplateDecl
*TD
= Name
.getAsTemplateDecl()) {
4978 NoteTemplateLocation(*TD
, TD
->getTemplateParameters()->getSourceRange());
4983 Sema::CheckConceptTemplateId(const CXXScopeSpec
&SS
,
4984 SourceLocation TemplateKWLoc
,
4985 const DeclarationNameInfo
&ConceptNameInfo
,
4986 NamedDecl
*FoundDecl
,
4987 ConceptDecl
*NamedConcept
,
4988 const TemplateArgumentListInfo
*TemplateArgs
) {
4989 assert(NamedConcept
&& "A concept template id without a template?");
4991 llvm::SmallVector
<TemplateArgument
, 4> SugaredConverted
, CanonicalConverted
;
4992 if (CheckTemplateArgumentList(
4993 NamedConcept
, ConceptNameInfo
.getLoc(),
4994 const_cast<TemplateArgumentListInfo
&>(*TemplateArgs
),
4995 /*PartialTemplateArgs=*/false, SugaredConverted
, CanonicalConverted
,
4996 /*UpdateArgsWithConversions=*/false))
4999 auto *CSD
= ImplicitConceptSpecializationDecl::Create(
5000 Context
, NamedConcept
->getDeclContext(), NamedConcept
->getLocation(),
5001 CanonicalConverted
);
5002 ConstraintSatisfaction Satisfaction
;
5003 bool AreArgsDependent
=
5004 TemplateSpecializationType::anyDependentTemplateArguments(
5005 *TemplateArgs
, CanonicalConverted
);
5006 MultiLevelTemplateArgumentList
MLTAL(NamedConcept
, CanonicalConverted
,
5008 LocalInstantiationScope
Scope(*this);
5010 EnterExpressionEvaluationContext EECtx
{
5011 *this, ExpressionEvaluationContext::ConstantEvaluated
, CSD
};
5013 if (!AreArgsDependent
&&
5014 CheckConstraintSatisfaction(
5015 NamedConcept
, {NamedConcept
->getConstraintExpr()}, MLTAL
,
5016 SourceRange(SS
.isSet() ? SS
.getBeginLoc() : ConceptNameInfo
.getLoc(),
5017 TemplateArgs
->getRAngleLoc()),
5020 auto *CL
= ConceptReference::Create(
5022 SS
.isSet() ? SS
.getWithLocInContext(Context
) : NestedNameSpecifierLoc
{},
5023 TemplateKWLoc
, ConceptNameInfo
, FoundDecl
, NamedConcept
,
5024 ASTTemplateArgumentListInfo::Create(Context
, *TemplateArgs
));
5025 return ConceptSpecializationExpr::Create(
5026 Context
, CL
, CSD
, AreArgsDependent
? nullptr : &Satisfaction
);
5029 ExprResult
Sema::BuildTemplateIdExpr(const CXXScopeSpec
&SS
,
5030 SourceLocation TemplateKWLoc
,
5033 const TemplateArgumentListInfo
*TemplateArgs
) {
5034 // FIXME: Can we do any checking at this point? I guess we could check the
5035 // template arguments that we have against the template name, if the template
5036 // name refers to a single template. That's not a terribly common case,
5038 // foo<int> could identify a single function unambiguously
5039 // This approach does NOT work, since f<int>(1);
5040 // gets resolved prior to resorting to overload resolution
5041 // i.e., template<class T> void f(double);
5042 // vs template<class T, class U> void f(U);
5044 // These should be filtered out by our callers.
5045 assert(!R
.isAmbiguous() && "ambiguous lookup when building templateid");
5047 // Non-function templates require a template argument list.
5048 if (auto *TD
= R
.getAsSingle
<TemplateDecl
>()) {
5049 if (!TemplateArgs
&& !isa
<FunctionTemplateDecl
>(TD
)) {
5050 diagnoseMissingTemplateArguments(TemplateName(TD
), R
.getNameLoc());
5054 bool KnownDependent
= false;
5055 // In C++1y, check variable template ids.
5056 if (R
.getAsSingle
<VarTemplateDecl
>()) {
5057 ExprResult Res
= CheckVarTemplateId(SS
, R
.getLookupNameInfo(),
5058 R
.getAsSingle
<VarTemplateDecl
>(),
5059 TemplateKWLoc
, TemplateArgs
);
5060 if (Res
.isInvalid() || Res
.isUsable())
5062 // Result is dependent. Carry on to build an UnresolvedLookupEpxr.
5063 KnownDependent
= true;
5066 if (R
.getAsSingle
<ConceptDecl
>()) {
5067 return CheckConceptTemplateId(SS
, TemplateKWLoc
, R
.getLookupNameInfo(),
5069 R
.getAsSingle
<ConceptDecl
>(), TemplateArgs
);
5072 // We don't want lookup warnings at this point.
5073 R
.suppressDiagnostics();
5075 UnresolvedLookupExpr
*ULE
= UnresolvedLookupExpr::Create(
5076 Context
, R
.getNamingClass(), SS
.getWithLocInContext(Context
),
5077 TemplateKWLoc
, R
.getLookupNameInfo(), RequiresADL
, TemplateArgs
,
5078 R
.begin(), R
.end(), KnownDependent
);
5083 // We actually only call this from template instantiation.
5085 Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec
&SS
,
5086 SourceLocation TemplateKWLoc
,
5087 const DeclarationNameInfo
&NameInfo
,
5088 const TemplateArgumentListInfo
*TemplateArgs
) {
5090 assert(TemplateArgs
|| TemplateKWLoc
.isValid());
5092 if (!(DC
= computeDeclContext(SS
, false)) ||
5093 DC
->isDependentContext() ||
5094 RequireCompleteDeclContext(SS
, DC
))
5095 return BuildDependentDeclRefExpr(SS
, TemplateKWLoc
, NameInfo
, TemplateArgs
);
5097 bool MemberOfUnknownSpecialization
;
5098 LookupResult
R(*this, NameInfo
, LookupOrdinaryName
);
5099 if (LookupTemplateName(R
, (Scope
*)nullptr, SS
, QualType(),
5100 /*Entering*/false, MemberOfUnknownSpecialization
,
5104 if (R
.isAmbiguous())
5108 Diag(NameInfo
.getLoc(), diag::err_no_member
)
5109 << NameInfo
.getName() << DC
<< SS
.getRange();
5113 auto DiagnoseTypeTemplateDecl
= [&](TemplateDecl
*Temp
,
5114 bool isTypeAliasTemplateDecl
) {
5115 Diag(NameInfo
.getLoc(), diag::err_template_kw_refers_to_type_template
)
5116 << SS
.getScopeRep() << NameInfo
.getName().getAsString() << SS
.getRange()
5117 << isTypeAliasTemplateDecl
;
5118 Diag(Temp
->getLocation(), diag::note_referenced_type_template
) << 0;
5122 if (ClassTemplateDecl
*Temp
= R
.getAsSingle
<ClassTemplateDecl
>())
5123 return DiagnoseTypeTemplateDecl(Temp
, false);
5125 if (TypeAliasTemplateDecl
*Temp
= R
.getAsSingle
<TypeAliasTemplateDecl
>())
5126 return DiagnoseTypeTemplateDecl(Temp
, true);
5128 return BuildTemplateIdExpr(SS
, TemplateKWLoc
, R
, /*ADL*/ false, TemplateArgs
);
5131 /// Form a template name from a name that is syntactically required to name a
5132 /// template, either due to use of the 'template' keyword or because a name in
5133 /// this syntactic context is assumed to name a template (C++ [temp.names]p2-4).
5135 /// This action forms a template name given the name of the template and its
5136 /// optional scope specifier. This is used when the 'template' keyword is used
5137 /// or when the parsing context unambiguously treats a following '<' as
5138 /// introducing a template argument list. Note that this may produce a
5139 /// non-dependent template name if we can perform the lookup now and identify
5140 /// the named template.
5142 /// For example, given "x.MetaFun::template apply", the scope specifier
5143 /// \p SS will be "MetaFun::", \p TemplateKWLoc contains the location
5144 /// of the "template" keyword, and "apply" is the \p Name.
5145 TemplateNameKind
Sema::ActOnTemplateName(Scope
*S
,
5147 SourceLocation TemplateKWLoc
,
5148 const UnqualifiedId
&Name
,
5149 ParsedType ObjectType
,
5150 bool EnteringContext
,
5152 bool AllowInjectedClassName
) {
5153 if (TemplateKWLoc
.isValid() && S
&& !S
->getTemplateParamParent())
5155 getLangOpts().CPlusPlus11
?
5156 diag::warn_cxx98_compat_template_outside_of_template
:
5157 diag::ext_template_outside_of_template
)
5158 << FixItHint::CreateRemoval(TemplateKWLoc
);
5161 return TNK_Non_template
;
5163 // Figure out where isTemplateName is going to look.
5164 DeclContext
*LookupCtx
= nullptr;
5165 if (SS
.isNotEmpty())
5166 LookupCtx
= computeDeclContext(SS
, EnteringContext
);
5167 else if (ObjectType
)
5168 LookupCtx
= computeDeclContext(GetTypeFromParser(ObjectType
));
5170 // C++0x [temp.names]p5:
5171 // If a name prefixed by the keyword template is not the name of
5172 // a template, the program is ill-formed. [Note: the keyword
5173 // template may not be applied to non-template members of class
5174 // templates. -end note ] [ Note: as is the case with the
5175 // typename prefix, the template prefix is allowed in cases
5176 // where it is not strictly necessary; i.e., when the
5177 // nested-name-specifier or the expression on the left of the ->
5178 // or . is not dependent on a template-parameter, or the use
5179 // does not appear in the scope of a template. -end note]
5181 // Note: C++03 was more strict here, because it banned the use of
5182 // the "template" keyword prior to a template-name that was not a
5183 // dependent name. C++ DR468 relaxed this requirement (the
5184 // "template" keyword is now permitted). We follow the C++0x
5185 // rules, even in C++03 mode with a warning, retroactively applying the DR.
5186 bool MemberOfUnknownSpecialization
;
5187 TemplateNameKind TNK
= isTemplateName(S
, SS
, TemplateKWLoc
.isValid(), Name
,
5188 ObjectType
, EnteringContext
, Result
,
5189 MemberOfUnknownSpecialization
);
5190 if (TNK
!= TNK_Non_template
) {
5191 // We resolved this to a (non-dependent) template name. Return it.
5192 auto *LookupRD
= dyn_cast_or_null
<CXXRecordDecl
>(LookupCtx
);
5193 if (!AllowInjectedClassName
&& SS
.isNotEmpty() && LookupRD
&&
5194 Name
.getKind() == UnqualifiedIdKind::IK_Identifier
&&
5195 Name
.Identifier
&& LookupRD
->getIdentifier() == Name
.Identifier
) {
5196 // C++14 [class.qual]p2:
5197 // In a lookup in which function names are not ignored and the
5198 // nested-name-specifier nominates a class C, if the name specified
5199 // [...] is the injected-class-name of C, [...] the name is instead
5200 // considered to name the constructor
5202 // We don't get here if naming the constructor would be valid, so we
5203 // just reject immediately and recover by treating the
5204 // injected-class-name as naming the template.
5205 Diag(Name
.getBeginLoc(),
5206 diag::ext_out_of_line_qualified_id_type_names_constructor
)
5208 << 0 /*injected-class-name used as template name*/
5209 << TemplateKWLoc
.isValid();
5214 if (!MemberOfUnknownSpecialization
) {
5215 // Didn't find a template name, and the lookup wasn't dependent.
5216 // Do the lookup again to determine if this is a "nothing found" case or
5217 // a "not a template" case. FIXME: Refactor isTemplateName so we don't
5219 DeclarationNameInfo DNI
= GetNameFromUnqualifiedId(Name
);
5220 LookupResult
R(*this, DNI
.getName(), Name
.getBeginLoc(),
5221 LookupOrdinaryName
);
5223 // Tell LookupTemplateName that we require a template so that it diagnoses
5224 // cases where it finds a non-template.
5225 RequiredTemplateKind RTK
= TemplateKWLoc
.isValid()
5226 ? RequiredTemplateKind(TemplateKWLoc
)
5227 : TemplateNameIsRequired
;
5228 if (!LookupTemplateName(R
, S
, SS
, ObjectType
.get(), EnteringContext
, MOUS
,
5229 RTK
, nullptr, /*AllowTypoCorrection=*/false) &&
5232 Diag(Name
.getBeginLoc(), diag::err_no_member
)
5233 << DNI
.getName() << LookupCtx
<< SS
.getRange();
5235 Diag(Name
.getBeginLoc(), diag::err_undeclared_use
)
5236 << DNI
.getName() << SS
.getRange();
5238 return TNK_Non_template
;
5241 NestedNameSpecifier
*Qualifier
= SS
.getScopeRep();
5243 switch (Name
.getKind()) {
5244 case UnqualifiedIdKind::IK_Identifier
:
5245 Result
= TemplateTy::make(
5246 Context
.getDependentTemplateName(Qualifier
, Name
.Identifier
));
5247 return TNK_Dependent_template_name
;
5249 case UnqualifiedIdKind::IK_OperatorFunctionId
:
5250 Result
= TemplateTy::make(Context
.getDependentTemplateName(
5251 Qualifier
, Name
.OperatorFunctionId
.Operator
));
5252 return TNK_Function_template
;
5254 case UnqualifiedIdKind::IK_LiteralOperatorId
:
5255 // This is a kind of template name, but can never occur in a dependent
5256 // scope (literal operators can only be declared at namespace scope).
5263 // This name cannot possibly name a dependent template. Diagnose this now
5264 // rather than building a dependent template name that can never be valid.
5265 Diag(Name
.getBeginLoc(),
5266 diag::err_template_kw_refers_to_dependent_non_template
)
5267 << GetNameFromUnqualifiedId(Name
).getName() << Name
.getSourceRange()
5268 << TemplateKWLoc
.isValid() << TemplateKWLoc
;
5269 return TNK_Non_template
;
5272 bool Sema::CheckTemplateTypeArgument(
5273 TemplateTypeParmDecl
*Param
, TemplateArgumentLoc
&AL
,
5274 SmallVectorImpl
<TemplateArgument
> &SugaredConverted
,
5275 SmallVectorImpl
<TemplateArgument
> &CanonicalConverted
) {
5276 const TemplateArgument
&Arg
= AL
.getArgument();
5278 TypeSourceInfo
*TSI
= nullptr;
5280 // Check template type parameter.
5281 switch(Arg
.getKind()) {
5282 case TemplateArgument::Type
:
5283 // C++ [temp.arg.type]p1:
5284 // A template-argument for a template-parameter which is a
5285 // type shall be a type-id.
5286 ArgType
= Arg
.getAsType();
5287 TSI
= AL
.getTypeSourceInfo();
5289 case TemplateArgument::Template
:
5290 case TemplateArgument::TemplateExpansion
: {
5291 // We have a template type parameter but the template argument
5292 // is a template without any arguments.
5293 SourceRange SR
= AL
.getSourceRange();
5294 TemplateName Name
= Arg
.getAsTemplateOrTemplatePattern();
5295 diagnoseMissingTemplateArguments(Name
, SR
.getEnd());
5298 case TemplateArgument::Expression
: {
5299 // We have a template type parameter but the template argument is an
5300 // expression; see if maybe it is missing the "typename" keyword.
5302 DeclarationNameInfo NameInfo
;
5304 if (DependentScopeDeclRefExpr
*ArgExpr
=
5305 dyn_cast
<DependentScopeDeclRefExpr
>(Arg
.getAsExpr())) {
5306 SS
.Adopt(ArgExpr
->getQualifierLoc());
5307 NameInfo
= ArgExpr
->getNameInfo();
5308 } else if (CXXDependentScopeMemberExpr
*ArgExpr
=
5309 dyn_cast
<CXXDependentScopeMemberExpr
>(Arg
.getAsExpr())) {
5310 if (ArgExpr
->isImplicitAccess()) {
5311 SS
.Adopt(ArgExpr
->getQualifierLoc());
5312 NameInfo
= ArgExpr
->getMemberNameInfo();
5316 if (auto *II
= NameInfo
.getName().getAsIdentifierInfo()) {
5317 LookupResult
Result(*this, NameInfo
, LookupOrdinaryName
);
5318 LookupParsedName(Result
, CurScope
, &SS
);
5320 if (Result
.getAsSingle
<TypeDecl
>() ||
5321 Result
.getResultKind() ==
5322 LookupResult::NotFoundInCurrentInstantiation
) {
5323 assert(SS
.getScopeRep() && "dependent scope expr must has a scope!");
5324 // Suggest that the user add 'typename' before the NNS.
5325 SourceLocation Loc
= AL
.getSourceRange().getBegin();
5326 Diag(Loc
, getLangOpts().MSVCCompat
5327 ? diag::ext_ms_template_type_arg_missing_typename
5328 : diag::err_template_arg_must_be_type_suggest
)
5329 << FixItHint::CreateInsertion(Loc
, "typename ");
5330 NoteTemplateParameterLocation(*Param
);
5332 // Recover by synthesizing a type using the location information that we
5334 ArgType
= Context
.getDependentNameType(ElaboratedTypeKeyword::Typename
,
5335 SS
.getScopeRep(), II
);
5337 DependentNameTypeLoc TL
= TLB
.push
<DependentNameTypeLoc
>(ArgType
);
5338 TL
.setElaboratedKeywordLoc(SourceLocation(/*synthesized*/));
5339 TL
.setQualifierLoc(SS
.getWithLocInContext(Context
));
5340 TL
.setNameLoc(NameInfo
.getLoc());
5341 TSI
= TLB
.getTypeSourceInfo(Context
, ArgType
);
5343 // Overwrite our input TemplateArgumentLoc so that we can recover
5345 AL
= TemplateArgumentLoc(TemplateArgument(ArgType
),
5346 TemplateArgumentLocInfo(TSI
));
5355 // We have a template type parameter but the template argument
5357 SourceRange SR
= AL
.getSourceRange();
5358 Diag(SR
.getBegin(), diag::err_template_arg_must_be_type
) << SR
;
5359 NoteTemplateParameterLocation(*Param
);
5365 if (CheckTemplateArgument(TSI
))
5369 // If an explicitly-specified template argument type is a lifetime type
5370 // with no lifetime qualifier, the __strong lifetime qualifier is inferred.
5371 if (getLangOpts().ObjCAutoRefCount
&&
5372 ArgType
->isObjCLifetimeType() &&
5373 !ArgType
.getObjCLifetime()) {
5375 Qs
.setObjCLifetime(Qualifiers::OCL_Strong
);
5376 ArgType
= Context
.getQualifiedType(ArgType
, Qs
);
5379 SugaredConverted
.push_back(TemplateArgument(ArgType
));
5380 CanonicalConverted
.push_back(
5381 TemplateArgument(Context
.getCanonicalType(ArgType
)));
5385 /// Substitute template arguments into the default template argument for
5386 /// the given template type parameter.
5388 /// \param SemaRef the semantic analysis object for which we are performing
5389 /// the substitution.
5391 /// \param Template the template that we are synthesizing template arguments
5394 /// \param TemplateLoc the location of the template name that started the
5395 /// template-id we are checking.
5397 /// \param RAngleLoc the location of the right angle bracket ('>') that
5398 /// terminates the template-id.
5400 /// \param Param the template template parameter whose default we are
5401 /// substituting into.
5403 /// \param Converted the list of template arguments provided for template
5404 /// parameters that precede \p Param in the template parameter list.
5405 /// \returns the substituted template argument, or NULL if an error occurred.
5406 static TypeSourceInfo
*SubstDefaultTemplateArgument(
5407 Sema
&SemaRef
, TemplateDecl
*Template
, SourceLocation TemplateLoc
,
5408 SourceLocation RAngleLoc
, TemplateTypeParmDecl
*Param
,
5409 ArrayRef
<TemplateArgument
> SugaredConverted
,
5410 ArrayRef
<TemplateArgument
> CanonicalConverted
) {
5411 TypeSourceInfo
*ArgType
= Param
->getDefaultArgumentInfo();
5413 // If the argument type is dependent, instantiate it now based
5414 // on the previously-computed template arguments.
5415 if (ArgType
->getType()->isInstantiationDependentType()) {
5416 Sema::InstantiatingTemplate
Inst(SemaRef
, TemplateLoc
, Param
, Template
,
5418 SourceRange(TemplateLoc
, RAngleLoc
));
5419 if (Inst
.isInvalid())
5422 // Only substitute for the innermost template argument list.
5423 MultiLevelTemplateArgumentList
TemplateArgLists(Template
, SugaredConverted
,
5425 for (unsigned i
= 0, e
= Param
->getDepth(); i
!= e
; ++i
)
5426 TemplateArgLists
.addOuterTemplateArguments(std::nullopt
);
5428 bool ForLambdaCallOperator
= false;
5429 if (const auto *Rec
= dyn_cast
<CXXRecordDecl
>(Template
->getDeclContext()))
5430 ForLambdaCallOperator
= Rec
->isLambda();
5431 Sema::ContextRAII
SavedContext(SemaRef
, Template
->getDeclContext(),
5432 !ForLambdaCallOperator
);
5434 SemaRef
.SubstType(ArgType
, TemplateArgLists
,
5435 Param
->getDefaultArgumentLoc(), Param
->getDeclName());
5441 /// Substitute template arguments into the default template argument for
5442 /// the given non-type template parameter.
5444 /// \param SemaRef the semantic analysis object for which we are performing
5445 /// the substitution.
5447 /// \param Template the template that we are synthesizing template arguments
5450 /// \param TemplateLoc the location of the template name that started the
5451 /// template-id we are checking.
5453 /// \param RAngleLoc the location of the right angle bracket ('>') that
5454 /// terminates the template-id.
5456 /// \param Param the non-type template parameter whose default we are
5457 /// substituting into.
5459 /// \param Converted the list of template arguments provided for template
5460 /// parameters that precede \p Param in the template parameter list.
5462 /// \returns the substituted template argument, or NULL if an error occurred.
5463 static ExprResult
SubstDefaultTemplateArgument(
5464 Sema
&SemaRef
, TemplateDecl
*Template
, SourceLocation TemplateLoc
,
5465 SourceLocation RAngleLoc
, NonTypeTemplateParmDecl
*Param
,
5466 ArrayRef
<TemplateArgument
> SugaredConverted
,
5467 ArrayRef
<TemplateArgument
> CanonicalConverted
) {
5468 Sema::InstantiatingTemplate
Inst(SemaRef
, TemplateLoc
, Param
, Template
,
5470 SourceRange(TemplateLoc
, RAngleLoc
));
5471 if (Inst
.isInvalid())
5474 // Only substitute for the innermost template argument list.
5475 MultiLevelTemplateArgumentList
TemplateArgLists(Template
, SugaredConverted
,
5477 for (unsigned i
= 0, e
= Param
->getDepth(); i
!= e
; ++i
)
5478 TemplateArgLists
.addOuterTemplateArguments(std::nullopt
);
5480 Sema::ContextRAII
SavedContext(SemaRef
, Template
->getDeclContext());
5481 EnterExpressionEvaluationContext
ConstantEvaluated(
5482 SemaRef
, Sema::ExpressionEvaluationContext::ConstantEvaluated
);
5483 return SemaRef
.SubstExpr(Param
->getDefaultArgument(), TemplateArgLists
);
5486 /// Substitute template arguments into the default template argument for
5487 /// the given template template parameter.
5489 /// \param SemaRef the semantic analysis object for which we are performing
5490 /// the substitution.
5492 /// \param Template the template that we are synthesizing template arguments
5495 /// \param TemplateLoc the location of the template name that started the
5496 /// template-id we are checking.
5498 /// \param RAngleLoc the location of the right angle bracket ('>') that
5499 /// terminates the template-id.
5501 /// \param Param the template template parameter whose default we are
5502 /// substituting into.
5504 /// \param Converted the list of template arguments provided for template
5505 /// parameters that precede \p Param in the template parameter list.
5507 /// \param QualifierLoc Will be set to the nested-name-specifier (with
5508 /// source-location information) that precedes the template name.
5510 /// \returns the substituted template argument, or NULL if an error occurred.
5511 static TemplateName
SubstDefaultTemplateArgument(
5512 Sema
&SemaRef
, TemplateDecl
*Template
, SourceLocation TemplateLoc
,
5513 SourceLocation RAngleLoc
, TemplateTemplateParmDecl
*Param
,
5514 ArrayRef
<TemplateArgument
> SugaredConverted
,
5515 ArrayRef
<TemplateArgument
> CanonicalConverted
,
5516 NestedNameSpecifierLoc
&QualifierLoc
) {
5517 Sema::InstantiatingTemplate
Inst(
5518 SemaRef
, TemplateLoc
, TemplateParameter(Param
), Template
,
5519 SugaredConverted
, SourceRange(TemplateLoc
, RAngleLoc
));
5520 if (Inst
.isInvalid())
5521 return TemplateName();
5523 // Only substitute for the innermost template argument list.
5524 MultiLevelTemplateArgumentList
TemplateArgLists(Template
, SugaredConverted
,
5526 for (unsigned i
= 0, e
= Param
->getDepth(); i
!= e
; ++i
)
5527 TemplateArgLists
.addOuterTemplateArguments(std::nullopt
);
5529 Sema::ContextRAII
SavedContext(SemaRef
, Template
->getDeclContext());
5530 // Substitute into the nested-name-specifier first,
5531 QualifierLoc
= Param
->getDefaultArgument().getTemplateQualifierLoc();
5534 SemaRef
.SubstNestedNameSpecifierLoc(QualifierLoc
, TemplateArgLists
);
5536 return TemplateName();
5539 return SemaRef
.SubstTemplateName(
5541 Param
->getDefaultArgument().getArgument().getAsTemplate(),
5542 Param
->getDefaultArgument().getTemplateNameLoc(),
5546 /// If the given template parameter has a default template
5547 /// argument, substitute into that default template argument and
5548 /// return the corresponding template argument.
5549 TemplateArgumentLoc
Sema::SubstDefaultTemplateArgumentIfAvailable(
5550 TemplateDecl
*Template
, SourceLocation TemplateLoc
,
5551 SourceLocation RAngleLoc
, Decl
*Param
,
5552 ArrayRef
<TemplateArgument
> SugaredConverted
,
5553 ArrayRef
<TemplateArgument
> CanonicalConverted
, bool &HasDefaultArg
) {
5554 HasDefaultArg
= false;
5556 if (TemplateTypeParmDecl
*TypeParm
= dyn_cast
<TemplateTypeParmDecl
>(Param
)) {
5557 if (!hasReachableDefaultArgument(TypeParm
))
5558 return TemplateArgumentLoc();
5560 HasDefaultArg
= true;
5561 TypeSourceInfo
*DI
= SubstDefaultTemplateArgument(
5562 *this, Template
, TemplateLoc
, RAngleLoc
, TypeParm
, SugaredConverted
,
5563 CanonicalConverted
);
5565 return TemplateArgumentLoc(TemplateArgument(DI
->getType()), DI
);
5567 return TemplateArgumentLoc();
5570 if (NonTypeTemplateParmDecl
*NonTypeParm
5571 = dyn_cast
<NonTypeTemplateParmDecl
>(Param
)) {
5572 if (!hasReachableDefaultArgument(NonTypeParm
))
5573 return TemplateArgumentLoc();
5575 HasDefaultArg
= true;
5576 ExprResult Arg
= SubstDefaultTemplateArgument(
5577 *this, Template
, TemplateLoc
, RAngleLoc
, NonTypeParm
, SugaredConverted
,
5578 CanonicalConverted
);
5579 if (Arg
.isInvalid())
5580 return TemplateArgumentLoc();
5582 Expr
*ArgE
= Arg
.getAs
<Expr
>();
5583 return TemplateArgumentLoc(TemplateArgument(ArgE
), ArgE
);
5586 TemplateTemplateParmDecl
*TempTempParm
5587 = cast
<TemplateTemplateParmDecl
>(Param
);
5588 if (!hasReachableDefaultArgument(TempTempParm
))
5589 return TemplateArgumentLoc();
5591 HasDefaultArg
= true;
5592 NestedNameSpecifierLoc QualifierLoc
;
5593 TemplateName TName
= SubstDefaultTemplateArgument(
5594 *this, Template
, TemplateLoc
, RAngleLoc
, TempTempParm
, SugaredConverted
,
5595 CanonicalConverted
, QualifierLoc
);
5597 return TemplateArgumentLoc();
5599 return TemplateArgumentLoc(
5600 Context
, TemplateArgument(TName
),
5601 TempTempParm
->getDefaultArgument().getTemplateQualifierLoc(),
5602 TempTempParm
->getDefaultArgument().getTemplateNameLoc());
5605 /// Convert a template-argument that we parsed as a type into a template, if
5606 /// possible. C++ permits injected-class-names to perform dual service as
5607 /// template template arguments and as template type arguments.
5608 static TemplateArgumentLoc
5609 convertTypeTemplateArgumentToTemplate(ASTContext
&Context
, TypeLoc TLoc
) {
5610 // Extract and step over any surrounding nested-name-specifier.
5611 NestedNameSpecifierLoc QualLoc
;
5612 if (auto ETLoc
= TLoc
.getAs
<ElaboratedTypeLoc
>()) {
5613 if (ETLoc
.getTypePtr()->getKeyword() != ElaboratedTypeKeyword::None
)
5614 return TemplateArgumentLoc();
5616 QualLoc
= ETLoc
.getQualifierLoc();
5617 TLoc
= ETLoc
.getNamedTypeLoc();
5619 // If this type was written as an injected-class-name, it can be used as a
5620 // template template argument.
5621 if (auto InjLoc
= TLoc
.getAs
<InjectedClassNameTypeLoc
>())
5622 return TemplateArgumentLoc(Context
, InjLoc
.getTypePtr()->getTemplateName(),
5623 QualLoc
, InjLoc
.getNameLoc());
5625 // If this type was written as an injected-class-name, it may have been
5626 // converted to a RecordType during instantiation. If the RecordType is
5627 // *not* wrapped in a TemplateSpecializationType and denotes a class
5628 // template specialization, it must have come from an injected-class-name.
5629 if (auto RecLoc
= TLoc
.getAs
<RecordTypeLoc
>())
5631 dyn_cast
<ClassTemplateSpecializationDecl
>(RecLoc
.getDecl()))
5632 return TemplateArgumentLoc(Context
,
5633 TemplateName(CTSD
->getSpecializedTemplate()),
5634 QualLoc
, RecLoc
.getNameLoc());
5636 return TemplateArgumentLoc();
5639 /// Check that the given template argument corresponds to the given
5640 /// template parameter.
5642 /// \param Param The template parameter against which the argument will be
5645 /// \param Arg The template argument, which may be updated due to conversions.
5647 /// \param Template The template in which the template argument resides.
5649 /// \param TemplateLoc The location of the template name for the template
5650 /// whose argument list we're matching.
5652 /// \param RAngleLoc The location of the right angle bracket ('>') that closes
5653 /// the template argument list.
5655 /// \param ArgumentPackIndex The index into the argument pack where this
5656 /// argument will be placed. Only valid if the parameter is a parameter pack.
5658 /// \param Converted The checked, converted argument will be added to the
5659 /// end of this small vector.
5661 /// \param CTAK Describes how we arrived at this particular template argument:
5662 /// explicitly written, deduced, etc.
5664 /// \returns true on error, false otherwise.
5665 bool Sema::CheckTemplateArgument(
5666 NamedDecl
*Param
, TemplateArgumentLoc
&Arg
, NamedDecl
*Template
,
5667 SourceLocation TemplateLoc
, SourceLocation RAngleLoc
,
5668 unsigned ArgumentPackIndex
,
5669 SmallVectorImpl
<TemplateArgument
> &SugaredConverted
,
5670 SmallVectorImpl
<TemplateArgument
> &CanonicalConverted
,
5671 CheckTemplateArgumentKind CTAK
) {
5672 // Check template type parameters.
5673 if (TemplateTypeParmDecl
*TTP
= dyn_cast
<TemplateTypeParmDecl
>(Param
))
5674 return CheckTemplateTypeArgument(TTP
, Arg
, SugaredConverted
,
5675 CanonicalConverted
);
5677 // Check non-type template parameters.
5678 if (NonTypeTemplateParmDecl
*NTTP
=dyn_cast
<NonTypeTemplateParmDecl
>(Param
)) {
5679 // Do substitution on the type of the non-type template parameter
5680 // with the template arguments we've seen thus far. But if the
5681 // template has a dependent context then we cannot substitute yet.
5682 QualType NTTPType
= NTTP
->getType();
5683 if (NTTP
->isParameterPack() && NTTP
->isExpandedParameterPack())
5684 NTTPType
= NTTP
->getExpansionType(ArgumentPackIndex
);
5686 if (NTTPType
->isInstantiationDependentType() &&
5687 !isa
<TemplateTemplateParmDecl
>(Template
) &&
5688 !Template
->getDeclContext()->isDependentContext()) {
5689 // Do substitution on the type of the non-type template parameter.
5690 InstantiatingTemplate
Inst(*this, TemplateLoc
, Template
, NTTP
,
5692 SourceRange(TemplateLoc
, RAngleLoc
));
5693 if (Inst
.isInvalid())
5696 MultiLevelTemplateArgumentList
MLTAL(Template
, SugaredConverted
,
5698 // If the parameter is a pack expansion, expand this slice of the pack.
5699 if (auto *PET
= NTTPType
->getAs
<PackExpansionType
>()) {
5700 Sema::ArgumentPackSubstitutionIndexRAII
SubstIndex(*this,
5702 NTTPType
= SubstType(PET
->getPattern(), MLTAL
, NTTP
->getLocation(),
5703 NTTP
->getDeclName());
5705 NTTPType
= SubstType(NTTPType
, MLTAL
, NTTP
->getLocation(),
5706 NTTP
->getDeclName());
5709 // If that worked, check the non-type template parameter type
5711 if (!NTTPType
.isNull())
5712 NTTPType
= CheckNonTypeTemplateParameterType(NTTPType
,
5713 NTTP
->getLocation());
5714 if (NTTPType
.isNull())
5718 switch (Arg
.getArgument().getKind()) {
5719 case TemplateArgument::Null
:
5720 llvm_unreachable("Should never see a NULL template argument here");
5722 case TemplateArgument::Expression
: {
5723 Expr
*E
= Arg
.getArgument().getAsExpr();
5724 TemplateArgument SugaredResult
, CanonicalResult
;
5725 unsigned CurSFINAEErrors
= NumSFINAEErrors
;
5726 ExprResult Res
= CheckTemplateArgument(NTTP
, NTTPType
, E
, SugaredResult
,
5727 CanonicalResult
, CTAK
);
5728 if (Res
.isInvalid())
5730 // If the current template argument causes an error, give up now.
5731 if (CurSFINAEErrors
< NumSFINAEErrors
)
5734 // If the resulting expression is new, then use it in place of the
5735 // old expression in the template argument.
5736 if (Res
.get() != E
) {
5737 TemplateArgument
TA(Res
.get());
5738 Arg
= TemplateArgumentLoc(TA
, Res
.get());
5741 SugaredConverted
.push_back(SugaredResult
);
5742 CanonicalConverted
.push_back(CanonicalResult
);
5746 case TemplateArgument::Declaration
:
5747 case TemplateArgument::Integral
:
5748 case TemplateArgument::NullPtr
:
5749 // We've already checked this template argument, so just copy
5750 // it to the list of converted arguments.
5751 SugaredConverted
.push_back(Arg
.getArgument());
5752 CanonicalConverted
.push_back(
5753 Context
.getCanonicalTemplateArgument(Arg
.getArgument()));
5756 case TemplateArgument::Template
:
5757 case TemplateArgument::TemplateExpansion
:
5758 // We were given a template template argument. It may not be ill-formed;
5760 if (DependentTemplateName
*DTN
5761 = Arg
.getArgument().getAsTemplateOrTemplatePattern()
5762 .getAsDependentTemplateName()) {
5763 // We have a template argument such as \c T::template X, which we
5764 // parsed as a template template argument. However, since we now
5765 // know that we need a non-type template argument, convert this
5766 // template name into an expression.
5768 DeclarationNameInfo
NameInfo(DTN
->getIdentifier(),
5769 Arg
.getTemplateNameLoc());
5772 SS
.Adopt(Arg
.getTemplateQualifierLoc());
5773 // FIXME: the template-template arg was a DependentTemplateName,
5774 // so it was provided with a template keyword. However, its source
5775 // location is not stored in the template argument structure.
5776 SourceLocation TemplateKWLoc
;
5777 ExprResult E
= DependentScopeDeclRefExpr::Create(
5778 Context
, SS
.getWithLocInContext(Context
), TemplateKWLoc
, NameInfo
,
5781 // If we parsed the template argument as a pack expansion, create a
5782 // pack expansion expression.
5783 if (Arg
.getArgument().getKind() == TemplateArgument::TemplateExpansion
){
5784 E
= ActOnPackExpansion(E
.get(), Arg
.getTemplateEllipsisLoc());
5789 TemplateArgument SugaredResult
, CanonicalResult
;
5790 E
= CheckTemplateArgument(NTTP
, NTTPType
, E
.get(), SugaredResult
,
5791 CanonicalResult
, CTAK_Specified
);
5795 SugaredConverted
.push_back(SugaredResult
);
5796 CanonicalConverted
.push_back(CanonicalResult
);
5800 // We have a template argument that actually does refer to a class
5801 // template, alias template, or template template parameter, and
5802 // therefore cannot be a non-type template argument.
5803 Diag(Arg
.getLocation(), diag::err_template_arg_must_be_expr
)
5804 << Arg
.getSourceRange();
5805 NoteTemplateParameterLocation(*Param
);
5809 case TemplateArgument::Type
: {
5810 // We have a non-type template parameter but the template
5811 // argument is a type.
5813 // C++ [temp.arg]p2:
5814 // In a template-argument, an ambiguity between a type-id and
5815 // an expression is resolved to a type-id, regardless of the
5816 // form of the corresponding template-parameter.
5818 // We warn specifically about this case, since it can be rather
5819 // confusing for users.
5820 QualType T
= Arg
.getArgument().getAsType();
5821 SourceRange SR
= Arg
.getSourceRange();
5822 if (T
->isFunctionType())
5823 Diag(SR
.getBegin(), diag::err_template_arg_nontype_ambig
) << SR
<< T
;
5825 Diag(SR
.getBegin(), diag::err_template_arg_must_be_expr
) << SR
;
5826 NoteTemplateParameterLocation(*Param
);
5830 case TemplateArgument::Pack
:
5831 llvm_unreachable("Caller must expand template argument packs");
5838 // Check template template parameters.
5839 TemplateTemplateParmDecl
*TempParm
= cast
<TemplateTemplateParmDecl
>(Param
);
5841 TemplateParameterList
*Params
= TempParm
->getTemplateParameters();
5842 if (TempParm
->isExpandedParameterPack())
5843 Params
= TempParm
->getExpansionTemplateParameters(ArgumentPackIndex
);
5845 // Substitute into the template parameter list of the template
5846 // template parameter, since previously-supplied template arguments
5847 // may appear within the template template parameter.
5849 // FIXME: Skip this if the parameters aren't instantiation-dependent.
5851 // Set up a template instantiation context.
5852 LocalInstantiationScope
Scope(*this);
5853 InstantiatingTemplate
Inst(*this, TemplateLoc
, Template
, TempParm
,
5855 SourceRange(TemplateLoc
, RAngleLoc
));
5856 if (Inst
.isInvalid())
5860 SubstTemplateParams(Params
, CurContext
,
5861 MultiLevelTemplateArgumentList(
5862 Template
, SugaredConverted
, /*Final=*/true),
5863 /*EvaluateConstraints=*/false);
5868 // C++1z [temp.local]p1: (DR1004)
5869 // When [the injected-class-name] is used [...] as a template-argument for
5870 // a template template-parameter [...] it refers to the class template
5872 if (Arg
.getArgument().getKind() == TemplateArgument::Type
) {
5873 TemplateArgumentLoc ConvertedArg
= convertTypeTemplateArgumentToTemplate(
5874 Context
, Arg
.getTypeSourceInfo()->getTypeLoc());
5875 if (!ConvertedArg
.getArgument().isNull())
5879 switch (Arg
.getArgument().getKind()) {
5880 case TemplateArgument::Null
:
5881 llvm_unreachable("Should never see a NULL template argument here");
5883 case TemplateArgument::Template
:
5884 case TemplateArgument::TemplateExpansion
:
5885 if (CheckTemplateTemplateArgument(TempParm
, Params
, Arg
))
5888 SugaredConverted
.push_back(Arg
.getArgument());
5889 CanonicalConverted
.push_back(
5890 Context
.getCanonicalTemplateArgument(Arg
.getArgument()));
5893 case TemplateArgument::Expression
:
5894 case TemplateArgument::Type
:
5895 // We have a template template parameter but the template
5896 // argument does not refer to a template.
5897 Diag(Arg
.getLocation(), diag::err_template_arg_must_be_template
)
5898 << getLangOpts().CPlusPlus11
;
5901 case TemplateArgument::Declaration
:
5902 llvm_unreachable("Declaration argument with template template parameter");
5903 case TemplateArgument::Integral
:
5904 llvm_unreachable("Integral argument with template template parameter");
5905 case TemplateArgument::NullPtr
:
5906 llvm_unreachable("Null pointer argument with template template parameter");
5908 case TemplateArgument::Pack
:
5909 llvm_unreachable("Caller must expand template argument packs");
5915 /// Diagnose a missing template argument.
5916 template<typename TemplateParmDecl
>
5917 static bool diagnoseMissingArgument(Sema
&S
, SourceLocation Loc
,
5919 const TemplateParmDecl
*D
,
5920 TemplateArgumentListInfo
&Args
) {
5921 // Dig out the most recent declaration of the template parameter; there may be
5922 // declarations of the template that are more recent than TD.
5923 D
= cast
<TemplateParmDecl
>(cast
<TemplateDecl
>(TD
->getMostRecentDecl())
5924 ->getTemplateParameters()
5925 ->getParam(D
->getIndex()));
5927 // If there's a default argument that's not reachable, diagnose that we're
5928 // missing a module import.
5929 llvm::SmallVector
<Module
*, 8> Modules
;
5930 if (D
->hasDefaultArgument() && !S
.hasReachableDefaultArgument(D
, &Modules
)) {
5931 S
.diagnoseMissingImport(Loc
, cast
<NamedDecl
>(TD
),
5932 D
->getDefaultArgumentLoc(), Modules
,
5933 Sema::MissingImportKind::DefaultArgument
,
5938 // FIXME: If there's a more recent default argument that *is* visible,
5939 // diagnose that it was declared too late.
5941 TemplateParameterList
*Params
= TD
->getTemplateParameters();
5943 S
.Diag(Loc
, diag::err_template_arg_list_different_arity
)
5944 << /*not enough args*/0
5945 << (int)S
.getTemplateNameKindForDiagnostics(TemplateName(TD
))
5947 S
.NoteTemplateLocation(*TD
, Params
->getSourceRange());
5951 /// Check that the given template argument list is well-formed
5952 /// for specializing the given template.
5953 bool Sema::CheckTemplateArgumentList(
5954 TemplateDecl
*Template
, SourceLocation TemplateLoc
,
5955 TemplateArgumentListInfo
&TemplateArgs
, bool PartialTemplateArgs
,
5956 SmallVectorImpl
<TemplateArgument
> &SugaredConverted
,
5957 SmallVectorImpl
<TemplateArgument
> &CanonicalConverted
,
5958 bool UpdateArgsWithConversions
, bool *ConstraintsNotSatisfied
) {
5960 if (ConstraintsNotSatisfied
)
5961 *ConstraintsNotSatisfied
= false;
5963 // Make a copy of the template arguments for processing. Only make the
5964 // changes at the end when successful in matching the arguments to the
5966 TemplateArgumentListInfo NewArgs
= TemplateArgs
;
5968 TemplateParameterList
*Params
= GetTemplateParameterList(Template
);
5970 SourceLocation RAngleLoc
= NewArgs
.getRAngleLoc();
5972 // C++ [temp.arg]p1:
5973 // [...] The type and form of each template-argument specified in
5974 // a template-id shall match the type and form specified for the
5975 // corresponding parameter declared by the template in its
5976 // template-parameter-list.
5977 bool isTemplateTemplateParameter
= isa
<TemplateTemplateParmDecl
>(Template
);
5978 SmallVector
<TemplateArgument
, 2> SugaredArgumentPack
;
5979 SmallVector
<TemplateArgument
, 2> CanonicalArgumentPack
;
5980 unsigned ArgIdx
= 0, NumArgs
= NewArgs
.size();
5981 LocalInstantiationScope
InstScope(*this, true);
5982 for (TemplateParameterList::iterator Param
= Params
->begin(),
5983 ParamEnd
= Params
->end();
5984 Param
!= ParamEnd
; /* increment in loop */) {
5985 // If we have an expanded parameter pack, make sure we don't have too
5987 if (std::optional
<unsigned> Expansions
= getExpandedPackSize(*Param
)) {
5988 if (*Expansions
== SugaredArgumentPack
.size()) {
5989 // We're done with this parameter pack. Pack up its arguments and add
5990 // them to the list.
5991 SugaredConverted
.push_back(
5992 TemplateArgument::CreatePackCopy(Context
, SugaredArgumentPack
));
5993 SugaredArgumentPack
.clear();
5995 CanonicalConverted
.push_back(
5996 TemplateArgument::CreatePackCopy(Context
, CanonicalArgumentPack
));
5997 CanonicalArgumentPack
.clear();
5999 // This argument is assigned to the next parameter.
6002 } else if (ArgIdx
== NumArgs
&& !PartialTemplateArgs
) {
6003 // Not enough arguments for this parameter pack.
6004 Diag(TemplateLoc
, diag::err_template_arg_list_different_arity
)
6005 << /*not enough args*/0
6006 << (int)getTemplateNameKindForDiagnostics(TemplateName(Template
))
6008 NoteTemplateLocation(*Template
, Params
->getSourceRange());
6013 if (ArgIdx
< NumArgs
) {
6014 // Check the template argument we were given.
6015 if (CheckTemplateArgument(*Param
, NewArgs
[ArgIdx
], Template
, TemplateLoc
,
6016 RAngleLoc
, SugaredArgumentPack
.size(),
6017 SugaredConverted
, CanonicalConverted
,
6021 CanonicalConverted
.back().setIsDefaulted(
6022 clang::isSubstitutedDefaultArgument(
6023 Context
, NewArgs
[ArgIdx
].getArgument(), *Param
,
6024 CanonicalConverted
, Params
->getDepth()));
6026 bool PackExpansionIntoNonPack
=
6027 NewArgs
[ArgIdx
].getArgument().isPackExpansion() &&
6028 (!(*Param
)->isTemplateParameterPack() || getExpandedPackSize(*Param
));
6029 if (PackExpansionIntoNonPack
&& (isa
<TypeAliasTemplateDecl
>(Template
) ||
6030 isa
<ConceptDecl
>(Template
))) {
6031 // Core issue 1430: we have a pack expansion as an argument to an
6032 // alias template, and it's not part of a parameter pack. This
6033 // can't be canonicalized, so reject it now.
6034 // As for concepts - we cannot normalize constraints where this
6035 // situation exists.
6036 Diag(NewArgs
[ArgIdx
].getLocation(),
6037 diag::err_template_expansion_into_fixed_list
)
6038 << (isa
<ConceptDecl
>(Template
) ? 1 : 0)
6039 << NewArgs
[ArgIdx
].getSourceRange();
6040 NoteTemplateParameterLocation(**Param
);
6044 // We're now done with this argument.
6047 if ((*Param
)->isTemplateParameterPack()) {
6048 // The template parameter was a template parameter pack, so take the
6049 // deduced argument and place it on the argument pack. Note that we
6050 // stay on the same template parameter so that we can deduce more
6052 SugaredArgumentPack
.push_back(SugaredConverted
.pop_back_val());
6053 CanonicalArgumentPack
.push_back(CanonicalConverted
.pop_back_val());
6055 // Move to the next template parameter.
6059 // If we just saw a pack expansion into a non-pack, then directly convert
6060 // the remaining arguments, because we don't know what parameters they'll
6062 if (PackExpansionIntoNonPack
) {
6063 if (!SugaredArgumentPack
.empty()) {
6064 // If we were part way through filling in an expanded parameter pack,
6065 // fall back to just producing individual arguments.
6066 SugaredConverted
.insert(SugaredConverted
.end(),
6067 SugaredArgumentPack
.begin(),
6068 SugaredArgumentPack
.end());
6069 SugaredArgumentPack
.clear();
6071 CanonicalConverted
.insert(CanonicalConverted
.end(),
6072 CanonicalArgumentPack
.begin(),
6073 CanonicalArgumentPack
.end());
6074 CanonicalArgumentPack
.clear();
6077 while (ArgIdx
< NumArgs
) {
6078 const TemplateArgument
&Arg
= NewArgs
[ArgIdx
].getArgument();
6079 SugaredConverted
.push_back(Arg
);
6080 CanonicalConverted
.push_back(
6081 Context
.getCanonicalTemplateArgument(Arg
));
6091 // If we're checking a partial template argument list, we're done.
6092 if (PartialTemplateArgs
) {
6093 if ((*Param
)->isTemplateParameterPack() && !SugaredArgumentPack
.empty()) {
6094 SugaredConverted
.push_back(
6095 TemplateArgument::CreatePackCopy(Context
, SugaredArgumentPack
));
6096 CanonicalConverted
.push_back(
6097 TemplateArgument::CreatePackCopy(Context
, CanonicalArgumentPack
));
6102 // If we have a template parameter pack with no more corresponding
6103 // arguments, just break out now and we'll fill in the argument pack below.
6104 if ((*Param
)->isTemplateParameterPack()) {
6105 assert(!getExpandedPackSize(*Param
) &&
6106 "Should have dealt with this already");
6108 // A non-expanded parameter pack before the end of the parameter list
6109 // only occurs for an ill-formed template parameter list, unless we've
6110 // got a partial argument list for a function template, so just bail out.
6111 if (Param
+ 1 != ParamEnd
) {
6113 (Template
->getMostRecentDecl()->getKind() != Decl::Kind::Concept
) &&
6114 "Concept templates must have parameter packs at the end.");
6118 SugaredConverted
.push_back(
6119 TemplateArgument::CreatePackCopy(Context
, SugaredArgumentPack
));
6120 SugaredArgumentPack
.clear();
6122 CanonicalConverted
.push_back(
6123 TemplateArgument::CreatePackCopy(Context
, CanonicalArgumentPack
));
6124 CanonicalArgumentPack
.clear();
6130 // Check whether we have a default argument.
6131 TemplateArgumentLoc Arg
;
6133 // Retrieve the default template argument from the template
6134 // parameter. For each kind of template parameter, we substitute the
6135 // template arguments provided thus far and any "outer" template arguments
6136 // (when the template parameter was part of a nested template) into
6137 // the default argument.
6138 if (TemplateTypeParmDecl
*TTP
= dyn_cast
<TemplateTypeParmDecl
>(*Param
)) {
6139 if (!hasReachableDefaultArgument(TTP
))
6140 return diagnoseMissingArgument(*this, TemplateLoc
, Template
, TTP
,
6143 TypeSourceInfo
*ArgType
= SubstDefaultTemplateArgument(
6144 *this, Template
, TemplateLoc
, RAngleLoc
, TTP
, SugaredConverted
,
6145 CanonicalConverted
);
6149 Arg
= TemplateArgumentLoc(TemplateArgument(ArgType
->getType()),
6151 } else if (NonTypeTemplateParmDecl
*NTTP
6152 = dyn_cast
<NonTypeTemplateParmDecl
>(*Param
)) {
6153 if (!hasReachableDefaultArgument(NTTP
))
6154 return diagnoseMissingArgument(*this, TemplateLoc
, Template
, NTTP
,
6157 ExprResult E
= SubstDefaultTemplateArgument(
6158 *this, Template
, TemplateLoc
, RAngleLoc
, NTTP
, SugaredConverted
,
6159 CanonicalConverted
);
6163 Expr
*Ex
= E
.getAs
<Expr
>();
6164 Arg
= TemplateArgumentLoc(TemplateArgument(Ex
), Ex
);
6166 TemplateTemplateParmDecl
*TempParm
6167 = cast
<TemplateTemplateParmDecl
>(*Param
);
6169 if (!hasReachableDefaultArgument(TempParm
))
6170 return diagnoseMissingArgument(*this, TemplateLoc
, Template
, TempParm
,
6173 NestedNameSpecifierLoc QualifierLoc
;
6174 TemplateName Name
= SubstDefaultTemplateArgument(
6175 *this, Template
, TemplateLoc
, RAngleLoc
, TempParm
, SugaredConverted
,
6176 CanonicalConverted
, QualifierLoc
);
6180 Arg
= TemplateArgumentLoc(
6181 Context
, TemplateArgument(Name
), QualifierLoc
,
6182 TempParm
->getDefaultArgument().getTemplateNameLoc());
6185 // Introduce an instantiation record that describes where we are using
6186 // the default template argument. We're not actually instantiating a
6187 // template here, we just create this object to put a note into the
6189 InstantiatingTemplate
Inst(*this, RAngleLoc
, Template
, *Param
,
6191 SourceRange(TemplateLoc
, RAngleLoc
));
6192 if (Inst
.isInvalid())
6195 // Check the default template argument.
6196 if (CheckTemplateArgument(*Param
, Arg
, Template
, TemplateLoc
, RAngleLoc
, 0,
6197 SugaredConverted
, CanonicalConverted
,
6201 CanonicalConverted
.back().setIsDefaulted(true);
6203 // Core issue 150 (assumed resolution): if this is a template template
6204 // parameter, keep track of the default template arguments from the
6205 // template definition.
6206 if (isTemplateTemplateParameter
)
6207 NewArgs
.addArgument(Arg
);
6209 // Move to the next template parameter and argument.
6214 // If we're performing a partial argument substitution, allow any trailing
6215 // pack expansions; they might be empty. This can happen even if
6216 // PartialTemplateArgs is false (the list of arguments is complete but
6217 // still dependent).
6218 if (ArgIdx
< NumArgs
&& CurrentInstantiationScope
&&
6219 CurrentInstantiationScope
->getPartiallySubstitutedPack()) {
6220 while (ArgIdx
< NumArgs
&&
6221 NewArgs
[ArgIdx
].getArgument().isPackExpansion()) {
6222 const TemplateArgument
&Arg
= NewArgs
[ArgIdx
++].getArgument();
6223 SugaredConverted
.push_back(Arg
);
6224 CanonicalConverted
.push_back(Context
.getCanonicalTemplateArgument(Arg
));
6228 // If we have any leftover arguments, then there were too many arguments.
6229 // Complain and fail.
6230 if (ArgIdx
< NumArgs
) {
6231 Diag(TemplateLoc
, diag::err_template_arg_list_different_arity
)
6232 << /*too many args*/1
6233 << (int)getTemplateNameKindForDiagnostics(TemplateName(Template
))
6235 << SourceRange(NewArgs
[ArgIdx
].getLocation(), NewArgs
.getRAngleLoc());
6236 NoteTemplateLocation(*Template
, Params
->getSourceRange());
6240 // No problems found with the new argument list, propagate changes back
6242 if (UpdateArgsWithConversions
)
6243 TemplateArgs
= std::move(NewArgs
);
6245 if (!PartialTemplateArgs
) {
6246 TemplateArgumentList
StackTemplateArgs(TemplateArgumentList::OnStack
,
6247 CanonicalConverted
);
6248 // Setup the context/ThisScope for the case where we are needing to
6249 // re-instantiate constraints outside of normal instantiation.
6250 DeclContext
*NewContext
= Template
->getDeclContext();
6252 // If this template is in a template, make sure we extract the templated
6254 if (auto *TD
= dyn_cast
<TemplateDecl
>(NewContext
))
6255 NewContext
= Decl::castToDeclContext(TD
->getTemplatedDecl());
6256 auto *RD
= dyn_cast
<CXXRecordDecl
>(NewContext
);
6258 Qualifiers ThisQuals
;
6259 if (const auto *Method
=
6260 dyn_cast_or_null
<CXXMethodDecl
>(Template
->getTemplatedDecl()))
6261 ThisQuals
= Method
->getMethodQualifiers();
6263 ContextRAII
Context(*this, NewContext
);
6264 CXXThisScopeRAII(*this, RD
, ThisQuals
, RD
!= nullptr);
6266 MultiLevelTemplateArgumentList MLTAL
= getTemplateInstantiationArgs(
6267 Template
, NewContext
, /*Final=*/false, &StackTemplateArgs
,
6268 /*RelativeToPrimary=*/true,
6269 /*Pattern=*/nullptr,
6270 /*ForConceptInstantiation=*/true);
6271 if (EnsureTemplateArgumentListConstraints(
6273 SourceRange(TemplateLoc
, TemplateArgs
.getRAngleLoc()))) {
6274 if (ConstraintsNotSatisfied
)
6275 *ConstraintsNotSatisfied
= true;
6284 class UnnamedLocalNoLinkageFinder
6285 : public TypeVisitor
<UnnamedLocalNoLinkageFinder
, bool>
6290 typedef TypeVisitor
<UnnamedLocalNoLinkageFinder
, bool> inherited
;
6293 UnnamedLocalNoLinkageFinder(Sema
&S
, SourceRange SR
) : S(S
), SR(SR
) { }
6295 bool Visit(QualType T
) {
6296 return T
.isNull() ? false : inherited::Visit(T
.getTypePtr());
6299 #define TYPE(Class, Parent) \
6300 bool Visit##Class##Type(const Class##Type *);
6301 #define ABSTRACT_TYPE(Class, Parent) \
6302 bool Visit##Class##Type(const Class##Type *) { return false; }
6303 #define NON_CANONICAL_TYPE(Class, Parent) \
6304 bool Visit##Class##Type(const Class##Type *) { return false; }
6305 #include "clang/AST/TypeNodes.inc"
6307 bool VisitTagDecl(const TagDecl
*Tag
);
6308 bool VisitNestedNameSpecifier(NestedNameSpecifier
*NNS
);
6310 } // end anonymous namespace
6312 bool UnnamedLocalNoLinkageFinder::VisitBuiltinType(const BuiltinType
*) {
6316 bool UnnamedLocalNoLinkageFinder::VisitComplexType(const ComplexType
* T
) {
6317 return Visit(T
->getElementType());
6320 bool UnnamedLocalNoLinkageFinder::VisitPointerType(const PointerType
* T
) {
6321 return Visit(T
->getPointeeType());
6324 bool UnnamedLocalNoLinkageFinder::VisitBlockPointerType(
6325 const BlockPointerType
* T
) {
6326 return Visit(T
->getPointeeType());
6329 bool UnnamedLocalNoLinkageFinder::VisitLValueReferenceType(
6330 const LValueReferenceType
* T
) {
6331 return Visit(T
->getPointeeType());
6334 bool UnnamedLocalNoLinkageFinder::VisitRValueReferenceType(
6335 const RValueReferenceType
* T
) {
6336 return Visit(T
->getPointeeType());
6339 bool UnnamedLocalNoLinkageFinder::VisitMemberPointerType(
6340 const MemberPointerType
* T
) {
6341 return Visit(T
->getPointeeType()) || Visit(QualType(T
->getClass(), 0));
6344 bool UnnamedLocalNoLinkageFinder::VisitConstantArrayType(
6345 const ConstantArrayType
* T
) {
6346 return Visit(T
->getElementType());
6349 bool UnnamedLocalNoLinkageFinder::VisitIncompleteArrayType(
6350 const IncompleteArrayType
* T
) {
6351 return Visit(T
->getElementType());
6354 bool UnnamedLocalNoLinkageFinder::VisitVariableArrayType(
6355 const VariableArrayType
* T
) {
6356 return Visit(T
->getElementType());
6359 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedArrayType(
6360 const DependentSizedArrayType
* T
) {
6361 return Visit(T
->getElementType());
6364 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedExtVectorType(
6365 const DependentSizedExtVectorType
* T
) {
6366 return Visit(T
->getElementType());
6369 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedMatrixType(
6370 const DependentSizedMatrixType
*T
) {
6371 return Visit(T
->getElementType());
6374 bool UnnamedLocalNoLinkageFinder::VisitDependentAddressSpaceType(
6375 const DependentAddressSpaceType
*T
) {
6376 return Visit(T
->getPointeeType());
6379 bool UnnamedLocalNoLinkageFinder::VisitVectorType(const VectorType
* T
) {
6380 return Visit(T
->getElementType());
6383 bool UnnamedLocalNoLinkageFinder::VisitDependentVectorType(
6384 const DependentVectorType
*T
) {
6385 return Visit(T
->getElementType());
6388 bool UnnamedLocalNoLinkageFinder::VisitExtVectorType(const ExtVectorType
* T
) {
6389 return Visit(T
->getElementType());
6392 bool UnnamedLocalNoLinkageFinder::VisitConstantMatrixType(
6393 const ConstantMatrixType
*T
) {
6394 return Visit(T
->getElementType());
6397 bool UnnamedLocalNoLinkageFinder::VisitFunctionProtoType(
6398 const FunctionProtoType
* T
) {
6399 for (const auto &A
: T
->param_types()) {
6404 return Visit(T
->getReturnType());
6407 bool UnnamedLocalNoLinkageFinder::VisitFunctionNoProtoType(
6408 const FunctionNoProtoType
* T
) {
6409 return Visit(T
->getReturnType());
6412 bool UnnamedLocalNoLinkageFinder::VisitUnresolvedUsingType(
6413 const UnresolvedUsingType
*) {
6417 bool UnnamedLocalNoLinkageFinder::VisitTypeOfExprType(const TypeOfExprType
*) {
6421 bool UnnamedLocalNoLinkageFinder::VisitTypeOfType(const TypeOfType
* T
) {
6422 return Visit(T
->getUnmodifiedType());
6425 bool UnnamedLocalNoLinkageFinder::VisitDecltypeType(const DecltypeType
*) {
6429 bool UnnamedLocalNoLinkageFinder::VisitUnaryTransformType(
6430 const UnaryTransformType
*) {
6434 bool UnnamedLocalNoLinkageFinder::VisitAutoType(const AutoType
*T
) {
6435 return Visit(T
->getDeducedType());
6438 bool UnnamedLocalNoLinkageFinder::VisitDeducedTemplateSpecializationType(
6439 const DeducedTemplateSpecializationType
*T
) {
6440 return Visit(T
->getDeducedType());
6443 bool UnnamedLocalNoLinkageFinder::VisitRecordType(const RecordType
* T
) {
6444 return VisitTagDecl(T
->getDecl());
6447 bool UnnamedLocalNoLinkageFinder::VisitEnumType(const EnumType
* T
) {
6448 return VisitTagDecl(T
->getDecl());
6451 bool UnnamedLocalNoLinkageFinder::VisitTemplateTypeParmType(
6452 const TemplateTypeParmType
*) {
6456 bool UnnamedLocalNoLinkageFinder::VisitSubstTemplateTypeParmPackType(
6457 const SubstTemplateTypeParmPackType
*) {
6461 bool UnnamedLocalNoLinkageFinder::VisitTemplateSpecializationType(
6462 const TemplateSpecializationType
*) {
6466 bool UnnamedLocalNoLinkageFinder::VisitInjectedClassNameType(
6467 const InjectedClassNameType
* T
) {
6468 return VisitTagDecl(T
->getDecl());
6471 bool UnnamedLocalNoLinkageFinder::VisitDependentNameType(
6472 const DependentNameType
* T
) {
6473 return VisitNestedNameSpecifier(T
->getQualifier());
6476 bool UnnamedLocalNoLinkageFinder::VisitDependentTemplateSpecializationType(
6477 const DependentTemplateSpecializationType
* T
) {
6478 if (auto *Q
= T
->getQualifier())
6479 return VisitNestedNameSpecifier(Q
);
6483 bool UnnamedLocalNoLinkageFinder::VisitPackExpansionType(
6484 const PackExpansionType
* T
) {
6485 return Visit(T
->getPattern());
6488 bool UnnamedLocalNoLinkageFinder::VisitObjCObjectType(const ObjCObjectType
*) {
6492 bool UnnamedLocalNoLinkageFinder::VisitObjCInterfaceType(
6493 const ObjCInterfaceType
*) {
6497 bool UnnamedLocalNoLinkageFinder::VisitObjCObjectPointerType(
6498 const ObjCObjectPointerType
*) {
6502 bool UnnamedLocalNoLinkageFinder::VisitAtomicType(const AtomicType
* T
) {
6503 return Visit(T
->getValueType());
6506 bool UnnamedLocalNoLinkageFinder::VisitPipeType(const PipeType
* T
) {
6510 bool UnnamedLocalNoLinkageFinder::VisitBitIntType(const BitIntType
*T
) {
6514 bool UnnamedLocalNoLinkageFinder::VisitDependentBitIntType(
6515 const DependentBitIntType
*T
) {
6519 bool UnnamedLocalNoLinkageFinder::VisitTagDecl(const TagDecl
*Tag
) {
6520 if (Tag
->getDeclContext()->isFunctionOrMethod()) {
6521 S
.Diag(SR
.getBegin(),
6522 S
.getLangOpts().CPlusPlus11
?
6523 diag::warn_cxx98_compat_template_arg_local_type
:
6524 diag::ext_template_arg_local_type
)
6525 << S
.Context
.getTypeDeclType(Tag
) << SR
;
6529 if (!Tag
->hasNameForLinkage()) {
6530 S
.Diag(SR
.getBegin(),
6531 S
.getLangOpts().CPlusPlus11
?
6532 diag::warn_cxx98_compat_template_arg_unnamed_type
:
6533 diag::ext_template_arg_unnamed_type
) << SR
;
6534 S
.Diag(Tag
->getLocation(), diag::note_template_unnamed_type_here
);
6541 bool UnnamedLocalNoLinkageFinder::VisitNestedNameSpecifier(
6542 NestedNameSpecifier
*NNS
) {
6544 if (NNS
->getPrefix() && VisitNestedNameSpecifier(NNS
->getPrefix()))
6547 switch (NNS
->getKind()) {
6548 case NestedNameSpecifier::Identifier
:
6549 case NestedNameSpecifier::Namespace
:
6550 case NestedNameSpecifier::NamespaceAlias
:
6551 case NestedNameSpecifier::Global
:
6552 case NestedNameSpecifier::Super
:
6555 case NestedNameSpecifier::TypeSpec
:
6556 case NestedNameSpecifier::TypeSpecWithTemplate
:
6557 return Visit(QualType(NNS
->getAsType(), 0));
6559 llvm_unreachable("Invalid NestedNameSpecifier::Kind!");
6562 /// Check a template argument against its corresponding
6563 /// template type parameter.
6565 /// This routine implements the semantics of C++ [temp.arg.type]. It
6566 /// returns true if an error occurred, and false otherwise.
6567 bool Sema::CheckTemplateArgument(TypeSourceInfo
*ArgInfo
) {
6568 assert(ArgInfo
&& "invalid TypeSourceInfo");
6569 QualType Arg
= ArgInfo
->getType();
6570 SourceRange SR
= ArgInfo
->getTypeLoc().getSourceRange();
6571 QualType CanonArg
= Context
.getCanonicalType(Arg
);
6573 if (CanonArg
->isVariablyModifiedType()) {
6574 return Diag(SR
.getBegin(), diag::err_variably_modified_template_arg
) << Arg
;
6575 } else if (Context
.hasSameUnqualifiedType(Arg
, Context
.OverloadTy
)) {
6576 return Diag(SR
.getBegin(), diag::err_template_arg_overload_type
) << SR
;
6579 // C++03 [temp.arg.type]p2:
6580 // A local type, a type with no linkage, an unnamed type or a type
6581 // compounded from any of these types shall not be used as a
6582 // template-argument for a template type-parameter.
6584 // C++11 allows these, and even in C++03 we allow them as an extension with
6586 if (LangOpts
.CPlusPlus11
|| CanonArg
->hasUnnamedOrLocalType()) {
6587 UnnamedLocalNoLinkageFinder
Finder(*this, SR
);
6588 (void)Finder
.Visit(CanonArg
);
6594 enum NullPointerValueKind
{
6600 /// Determine whether the given template argument is a null pointer
6601 /// value of the appropriate type.
6602 static NullPointerValueKind
6603 isNullPointerValueTemplateArgument(Sema
&S
, NonTypeTemplateParmDecl
*Param
,
6604 QualType ParamType
, Expr
*Arg
,
6605 Decl
*Entity
= nullptr) {
6606 if (Arg
->isValueDependent() || Arg
->isTypeDependent())
6607 return NPV_NotNullPointer
;
6609 // dllimport'd entities aren't constant but are available inside of template
6611 if (Entity
&& Entity
->hasAttr
<DLLImportAttr
>())
6612 return NPV_NotNullPointer
;
6614 if (!S
.isCompleteType(Arg
->getExprLoc(), ParamType
))
6616 "Incomplete parameter type in isNullPointerValueTemplateArgument!");
6618 if (!S
.getLangOpts().CPlusPlus11
)
6619 return NPV_NotNullPointer
;
6621 // Determine whether we have a constant expression.
6622 ExprResult ArgRV
= S
.DefaultFunctionArrayConversion(Arg
);
6623 if (ArgRV
.isInvalid())
6627 Expr::EvalResult EvalResult
;
6628 SmallVector
<PartialDiagnosticAt
, 8> Notes
;
6629 EvalResult
.Diag
= &Notes
;
6630 if (!Arg
->EvaluateAsRValue(EvalResult
, S
.Context
) ||
6631 EvalResult
.HasSideEffects
) {
6632 SourceLocation DiagLoc
= Arg
->getExprLoc();
6634 // If our only note is the usual "invalid subexpression" note, just point
6635 // the caret at its location rather than producing an essentially
6637 if (Notes
.size() == 1 && Notes
[0].second
.getDiagID() ==
6638 diag::note_invalid_subexpr_in_const_expr
) {
6639 DiagLoc
= Notes
[0].first
;
6643 S
.Diag(DiagLoc
, diag::err_template_arg_not_address_constant
)
6644 << Arg
->getType() << Arg
->getSourceRange();
6645 for (unsigned I
= 0, N
= Notes
.size(); I
!= N
; ++I
)
6646 S
.Diag(Notes
[I
].first
, Notes
[I
].second
);
6648 S
.NoteTemplateParameterLocation(*Param
);
6652 // C++11 [temp.arg.nontype]p1:
6653 // - an address constant expression of type std::nullptr_t
6654 if (Arg
->getType()->isNullPtrType())
6655 return NPV_NullPointer
;
6657 // - a constant expression that evaluates to a null pointer value (4.10); or
6658 // - a constant expression that evaluates to a null member pointer value
6660 if ((EvalResult
.Val
.isLValue() && EvalResult
.Val
.isNullPointer()) ||
6661 (EvalResult
.Val
.isMemberPointer() &&
6662 !EvalResult
.Val
.getMemberPointerDecl())) {
6663 // If our expression has an appropriate type, we've succeeded.
6664 bool ObjCLifetimeConversion
;
6665 if (S
.Context
.hasSameUnqualifiedType(Arg
->getType(), ParamType
) ||
6666 S
.IsQualificationConversion(Arg
->getType(), ParamType
, false,
6667 ObjCLifetimeConversion
))
6668 return NPV_NullPointer
;
6670 // The types didn't match, but we know we got a null pointer; complain,
6671 // then recover as if the types were correct.
6672 S
.Diag(Arg
->getExprLoc(), diag::err_template_arg_wrongtype_null_constant
)
6673 << Arg
->getType() << ParamType
<< Arg
->getSourceRange();
6674 S
.NoteTemplateParameterLocation(*Param
);
6675 return NPV_NullPointer
;
6678 if (EvalResult
.Val
.isLValue() && !EvalResult
.Val
.getLValueBase()) {
6679 // We found a pointer that isn't null, but doesn't refer to an object.
6680 // We could just return NPV_NotNullPointer, but we can print a better
6681 // message with the information we have here.
6682 S
.Diag(Arg
->getExprLoc(), diag::err_template_arg_invalid
)
6683 << EvalResult
.Val
.getAsString(S
.Context
, ParamType
);
6684 S
.NoteTemplateParameterLocation(*Param
);
6688 // If we don't have a null pointer value, but we do have a NULL pointer
6689 // constant, suggest a cast to the appropriate type.
6690 if (Arg
->isNullPointerConstant(S
.Context
, Expr::NPC_NeverValueDependent
)) {
6691 std::string Code
= "static_cast<" + ParamType
.getAsString() + ">(";
6692 S
.Diag(Arg
->getExprLoc(), diag::err_template_arg_untyped_null_constant
)
6693 << ParamType
<< FixItHint::CreateInsertion(Arg
->getBeginLoc(), Code
)
6694 << FixItHint::CreateInsertion(S
.getLocForEndOfToken(Arg
->getEndLoc()),
6696 S
.NoteTemplateParameterLocation(*Param
);
6697 return NPV_NullPointer
;
6700 // FIXME: If we ever want to support general, address-constant expressions
6701 // as non-type template arguments, we should return the ExprResult here to
6702 // be interpreted by the caller.
6703 return NPV_NotNullPointer
;
6706 /// Checks whether the given template argument is compatible with its
6707 /// template parameter.
6708 static bool CheckTemplateArgumentIsCompatibleWithParameter(
6709 Sema
&S
, NonTypeTemplateParmDecl
*Param
, QualType ParamType
, Expr
*ArgIn
,
6710 Expr
*Arg
, QualType ArgType
) {
6711 bool ObjCLifetimeConversion
;
6712 if (ParamType
->isPointerType() &&
6713 !ParamType
->castAs
<PointerType
>()->getPointeeType()->isFunctionType() &&
6714 S
.IsQualificationConversion(ArgType
, ParamType
, false,
6715 ObjCLifetimeConversion
)) {
6716 // For pointer-to-object types, qualification conversions are
6719 if (const ReferenceType
*ParamRef
= ParamType
->getAs
<ReferenceType
>()) {
6720 if (!ParamRef
->getPointeeType()->isFunctionType()) {
6721 // C++ [temp.arg.nontype]p5b3:
6722 // For a non-type template-parameter of type reference to
6723 // object, no conversions apply. The type referred to by the
6724 // reference may be more cv-qualified than the (otherwise
6725 // identical) type of the template- argument. The
6726 // template-parameter is bound directly to the
6727 // template-argument, which shall be an lvalue.
6729 // FIXME: Other qualifiers?
6730 unsigned ParamQuals
= ParamRef
->getPointeeType().getCVRQualifiers();
6731 unsigned ArgQuals
= ArgType
.getCVRQualifiers();
6733 if ((ParamQuals
| ArgQuals
) != ParamQuals
) {
6734 S
.Diag(Arg
->getBeginLoc(),
6735 diag::err_template_arg_ref_bind_ignores_quals
)
6736 << ParamType
<< Arg
->getType() << Arg
->getSourceRange();
6737 S
.NoteTemplateParameterLocation(*Param
);
6743 // At this point, the template argument refers to an object or
6744 // function with external linkage. We now need to check whether the
6745 // argument and parameter types are compatible.
6746 if (!S
.Context
.hasSameUnqualifiedType(ArgType
,
6747 ParamType
.getNonReferenceType())) {
6748 // We can't perform this conversion or binding.
6749 if (ParamType
->isReferenceType())
6750 S
.Diag(Arg
->getBeginLoc(), diag::err_template_arg_no_ref_bind
)
6751 << ParamType
<< ArgIn
->getType() << Arg
->getSourceRange();
6753 S
.Diag(Arg
->getBeginLoc(), diag::err_template_arg_not_convertible
)
6754 << ArgIn
->getType() << ParamType
<< Arg
->getSourceRange();
6755 S
.NoteTemplateParameterLocation(*Param
);
6763 /// Checks whether the given template argument is the address
6764 /// of an object or function according to C++ [temp.arg.nontype]p1.
6765 static bool CheckTemplateArgumentAddressOfObjectOrFunction(
6766 Sema
&S
, NonTypeTemplateParmDecl
*Param
, QualType ParamType
, Expr
*ArgIn
,
6767 TemplateArgument
&SugaredConverted
, TemplateArgument
&CanonicalConverted
) {
6768 bool Invalid
= false;
6770 QualType ArgType
= Arg
->getType();
6772 bool AddressTaken
= false;
6773 SourceLocation AddrOpLoc
;
6774 if (S
.getLangOpts().MicrosoftExt
) {
6775 // Microsoft Visual C++ strips all casts, allows an arbitrary number of
6776 // dereference and address-of operators.
6777 Arg
= Arg
->IgnoreParenCasts();
6779 bool ExtWarnMSTemplateArg
= false;
6780 UnaryOperatorKind FirstOpKind
;
6781 SourceLocation FirstOpLoc
;
6782 while (UnaryOperator
*UnOp
= dyn_cast
<UnaryOperator
>(Arg
)) {
6783 UnaryOperatorKind UnOpKind
= UnOp
->getOpcode();
6784 if (UnOpKind
== UO_Deref
)
6785 ExtWarnMSTemplateArg
= true;
6786 if (UnOpKind
== UO_AddrOf
|| UnOpKind
== UO_Deref
) {
6787 Arg
= UnOp
->getSubExpr()->IgnoreParenCasts();
6788 if (!AddrOpLoc
.isValid()) {
6789 FirstOpKind
= UnOpKind
;
6790 FirstOpLoc
= UnOp
->getOperatorLoc();
6795 if (FirstOpLoc
.isValid()) {
6796 if (ExtWarnMSTemplateArg
)
6797 S
.Diag(ArgIn
->getBeginLoc(), diag::ext_ms_deref_template_argument
)
6798 << ArgIn
->getSourceRange();
6800 if (FirstOpKind
== UO_AddrOf
)
6801 AddressTaken
= true;
6802 else if (Arg
->getType()->isPointerType()) {
6803 // We cannot let pointers get dereferenced here, that is obviously not a
6804 // constant expression.
6805 assert(FirstOpKind
== UO_Deref
);
6806 S
.Diag(Arg
->getBeginLoc(), diag::err_template_arg_not_decl_ref
)
6807 << Arg
->getSourceRange();
6811 // See through any implicit casts we added to fix the type.
6812 Arg
= Arg
->IgnoreImpCasts();
6814 // C++ [temp.arg.nontype]p1:
6816 // A template-argument for a non-type, non-template
6817 // template-parameter shall be one of: [...]
6819 // -- the address of an object or function with external
6820 // linkage, including function templates and function
6821 // template-ids but excluding non-static class members,
6822 // expressed as & id-expression where the & is optional if
6823 // the name refers to a function or array, or if the
6824 // corresponding template-parameter is a reference; or
6826 // In C++98/03 mode, give an extension warning on any extra parentheses.
6827 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
6828 bool ExtraParens
= false;
6829 while (ParenExpr
*Parens
= dyn_cast
<ParenExpr
>(Arg
)) {
6830 if (!Invalid
&& !ExtraParens
) {
6831 S
.Diag(Arg
->getBeginLoc(),
6832 S
.getLangOpts().CPlusPlus11
6833 ? diag::warn_cxx98_compat_template_arg_extra_parens
6834 : diag::ext_template_arg_extra_parens
)
6835 << Arg
->getSourceRange();
6839 Arg
= Parens
->getSubExpr();
6842 while (SubstNonTypeTemplateParmExpr
*subst
=
6843 dyn_cast
<SubstNonTypeTemplateParmExpr
>(Arg
))
6844 Arg
= subst
->getReplacement()->IgnoreImpCasts();
6846 if (UnaryOperator
*UnOp
= dyn_cast
<UnaryOperator
>(Arg
)) {
6847 if (UnOp
->getOpcode() == UO_AddrOf
) {
6848 Arg
= UnOp
->getSubExpr();
6849 AddressTaken
= true;
6850 AddrOpLoc
= UnOp
->getOperatorLoc();
6854 while (SubstNonTypeTemplateParmExpr
*subst
=
6855 dyn_cast
<SubstNonTypeTemplateParmExpr
>(Arg
))
6856 Arg
= subst
->getReplacement()->IgnoreImpCasts();
6859 ValueDecl
*Entity
= nullptr;
6860 if (DeclRefExpr
*DRE
= dyn_cast
<DeclRefExpr
>(Arg
))
6861 Entity
= DRE
->getDecl();
6862 else if (CXXUuidofExpr
*CUE
= dyn_cast
<CXXUuidofExpr
>(Arg
))
6863 Entity
= CUE
->getGuidDecl();
6865 // If our parameter has pointer type, check for a null template value.
6866 if (ParamType
->isPointerType() || ParamType
->isNullPtrType()) {
6867 switch (isNullPointerValueTemplateArgument(S
, Param
, ParamType
, ArgIn
,
6869 case NPV_NullPointer
:
6870 S
.Diag(Arg
->getExprLoc(), diag::warn_cxx98_compat_template_arg_null
);
6871 SugaredConverted
= TemplateArgument(ParamType
,
6872 /*isNullPtr=*/true);
6873 CanonicalConverted
=
6874 TemplateArgument(S
.Context
.getCanonicalType(ParamType
),
6875 /*isNullPtr=*/true);
6881 case NPV_NotNullPointer
:
6886 // Stop checking the precise nature of the argument if it is value dependent,
6887 // it should be checked when instantiated.
6888 if (Arg
->isValueDependent()) {
6889 SugaredConverted
= TemplateArgument(ArgIn
);
6890 CanonicalConverted
=
6891 S
.Context
.getCanonicalTemplateArgument(SugaredConverted
);
6896 S
.Diag(Arg
->getBeginLoc(), diag::err_template_arg_not_decl_ref
)
6897 << Arg
->getSourceRange();
6898 S
.NoteTemplateParameterLocation(*Param
);
6902 // Cannot refer to non-static data members
6903 if (isa
<FieldDecl
>(Entity
) || isa
<IndirectFieldDecl
>(Entity
)) {
6904 S
.Diag(Arg
->getBeginLoc(), diag::err_template_arg_field
)
6905 << Entity
<< Arg
->getSourceRange();
6906 S
.NoteTemplateParameterLocation(*Param
);
6910 // Cannot refer to non-static member functions
6911 if (CXXMethodDecl
*Method
= dyn_cast
<CXXMethodDecl
>(Entity
)) {
6912 if (!Method
->isStatic()) {
6913 S
.Diag(Arg
->getBeginLoc(), diag::err_template_arg_method
)
6914 << Method
<< Arg
->getSourceRange();
6915 S
.NoteTemplateParameterLocation(*Param
);
6920 FunctionDecl
*Func
= dyn_cast
<FunctionDecl
>(Entity
);
6921 VarDecl
*Var
= dyn_cast
<VarDecl
>(Entity
);
6922 MSGuidDecl
*Guid
= dyn_cast
<MSGuidDecl
>(Entity
);
6924 // A non-type template argument must refer to an object or function.
6925 if (!Func
&& !Var
&& !Guid
) {
6926 // We found something, but we don't know specifically what it is.
6927 S
.Diag(Arg
->getBeginLoc(), diag::err_template_arg_not_object_or_func
)
6928 << Arg
->getSourceRange();
6929 S
.Diag(Entity
->getLocation(), diag::note_template_arg_refers_here
);
6933 // Address / reference template args must have external linkage in C++98.
6934 if (Entity
->getFormalLinkage() == Linkage::Internal
) {
6935 S
.Diag(Arg
->getBeginLoc(),
6936 S
.getLangOpts().CPlusPlus11
6937 ? diag::warn_cxx98_compat_template_arg_object_internal
6938 : diag::ext_template_arg_object_internal
)
6939 << !Func
<< Entity
<< Arg
->getSourceRange();
6940 S
.Diag(Entity
->getLocation(), diag::note_template_arg_internal_object
)
6942 } else if (!Entity
->hasLinkage()) {
6943 S
.Diag(Arg
->getBeginLoc(), diag::err_template_arg_object_no_linkage
)
6944 << !Func
<< Entity
<< Arg
->getSourceRange();
6945 S
.Diag(Entity
->getLocation(), diag::note_template_arg_internal_object
)
6951 // A value of reference type is not an object.
6952 if (Var
->getType()->isReferenceType()) {
6953 S
.Diag(Arg
->getBeginLoc(), diag::err_template_arg_reference_var
)
6954 << Var
->getType() << Arg
->getSourceRange();
6955 S
.NoteTemplateParameterLocation(*Param
);
6959 // A template argument must have static storage duration.
6960 if (Var
->getTLSKind()) {
6961 S
.Diag(Arg
->getBeginLoc(), diag::err_template_arg_thread_local
)
6962 << Arg
->getSourceRange();
6963 S
.Diag(Var
->getLocation(), diag::note_template_arg_refers_here
);
6968 if (AddressTaken
&& ParamType
->isReferenceType()) {
6969 // If we originally had an address-of operator, but the
6970 // parameter has reference type, complain and (if things look
6971 // like they will work) drop the address-of operator.
6972 if (!S
.Context
.hasSameUnqualifiedType(Entity
->getType(),
6973 ParamType
.getNonReferenceType())) {
6974 S
.Diag(AddrOpLoc
, diag::err_template_arg_address_of_non_pointer
)
6976 S
.NoteTemplateParameterLocation(*Param
);
6980 S
.Diag(AddrOpLoc
, diag::err_template_arg_address_of_non_pointer
)
6982 << FixItHint::CreateRemoval(AddrOpLoc
);
6983 S
.NoteTemplateParameterLocation(*Param
);
6985 ArgType
= Entity
->getType();
6988 // If the template parameter has pointer type, either we must have taken the
6989 // address or the argument must decay to a pointer.
6990 if (!AddressTaken
&& ParamType
->isPointerType()) {
6992 // Function-to-pointer decay.
6993 ArgType
= S
.Context
.getPointerType(Func
->getType());
6994 } else if (Entity
->getType()->isArrayType()) {
6995 // Array-to-pointer decay.
6996 ArgType
= S
.Context
.getArrayDecayedType(Entity
->getType());
6998 // If the template parameter has pointer type but the address of
6999 // this object was not taken, complain and (possibly) recover by
7000 // taking the address of the entity.
7001 ArgType
= S
.Context
.getPointerType(Entity
->getType());
7002 if (!S
.Context
.hasSameUnqualifiedType(ArgType
, ParamType
)) {
7003 S
.Diag(Arg
->getBeginLoc(), diag::err_template_arg_not_address_of
)
7005 S
.NoteTemplateParameterLocation(*Param
);
7009 S
.Diag(Arg
->getBeginLoc(), diag::err_template_arg_not_address_of
)
7010 << ParamType
<< FixItHint::CreateInsertion(Arg
->getBeginLoc(), "&");
7012 S
.NoteTemplateParameterLocation(*Param
);
7016 if (CheckTemplateArgumentIsCompatibleWithParameter(S
, Param
, ParamType
, ArgIn
,
7020 // Create the template argument.
7021 SugaredConverted
= TemplateArgument(Entity
, ParamType
);
7022 CanonicalConverted
=
7023 TemplateArgument(cast
<ValueDecl
>(Entity
->getCanonicalDecl()),
7024 S
.Context
.getCanonicalType(ParamType
));
7025 S
.MarkAnyDeclReferenced(Arg
->getBeginLoc(), Entity
, false);
7029 /// Checks whether the given template argument is a pointer to
7030 /// member constant according to C++ [temp.arg.nontype]p1.
7032 CheckTemplateArgumentPointerToMember(Sema
&S
, NonTypeTemplateParmDecl
*Param
,
7033 QualType ParamType
, Expr
*&ResultArg
,
7034 TemplateArgument
&SugaredConverted
,
7035 TemplateArgument
&CanonicalConverted
) {
7036 bool Invalid
= false;
7038 Expr
*Arg
= ResultArg
;
7039 bool ObjCLifetimeConversion
;
7041 // C++ [temp.arg.nontype]p1:
7043 // A template-argument for a non-type, non-template
7044 // template-parameter shall be one of: [...]
7046 // -- a pointer to member expressed as described in 5.3.1.
7047 DeclRefExpr
*DRE
= nullptr;
7049 // In C++98/03 mode, give an extension warning on any extra parentheses.
7050 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
7051 bool ExtraParens
= false;
7052 while (ParenExpr
*Parens
= dyn_cast
<ParenExpr
>(Arg
)) {
7053 if (!Invalid
&& !ExtraParens
) {
7054 S
.Diag(Arg
->getBeginLoc(),
7055 S
.getLangOpts().CPlusPlus11
7056 ? diag::warn_cxx98_compat_template_arg_extra_parens
7057 : diag::ext_template_arg_extra_parens
)
7058 << Arg
->getSourceRange();
7062 Arg
= Parens
->getSubExpr();
7065 while (SubstNonTypeTemplateParmExpr
*subst
=
7066 dyn_cast
<SubstNonTypeTemplateParmExpr
>(Arg
))
7067 Arg
= subst
->getReplacement()->IgnoreImpCasts();
7069 // A pointer-to-member constant written &Class::member.
7070 if (UnaryOperator
*UnOp
= dyn_cast
<UnaryOperator
>(Arg
)) {
7071 if (UnOp
->getOpcode() == UO_AddrOf
) {
7072 DRE
= dyn_cast
<DeclRefExpr
>(UnOp
->getSubExpr());
7073 if (DRE
&& !DRE
->getQualifier())
7077 // A constant of pointer-to-member type.
7078 else if ((DRE
= dyn_cast
<DeclRefExpr
>(Arg
))) {
7079 ValueDecl
*VD
= DRE
->getDecl();
7080 if (VD
->getType()->isMemberPointerType()) {
7081 if (isa
<NonTypeTemplateParmDecl
>(VD
)) {
7082 if (Arg
->isTypeDependent() || Arg
->isValueDependent()) {
7083 SugaredConverted
= TemplateArgument(Arg
);
7084 CanonicalConverted
=
7085 S
.Context
.getCanonicalTemplateArgument(SugaredConverted
);
7087 SugaredConverted
= TemplateArgument(VD
, ParamType
);
7088 CanonicalConverted
=
7089 TemplateArgument(cast
<ValueDecl
>(VD
->getCanonicalDecl()),
7090 S
.Context
.getCanonicalType(ParamType
));
7099 ValueDecl
*Entity
= DRE
? DRE
->getDecl() : nullptr;
7101 // Check for a null pointer value.
7102 switch (isNullPointerValueTemplateArgument(S
, Param
, ParamType
, ResultArg
,
7106 case NPV_NullPointer
:
7107 S
.Diag(ResultArg
->getExprLoc(), diag::warn_cxx98_compat_template_arg_null
);
7108 SugaredConverted
= TemplateArgument(ParamType
,
7109 /*isNullPtr*/ true);
7110 CanonicalConverted
= TemplateArgument(S
.Context
.getCanonicalType(ParamType
),
7111 /*isNullPtr*/ true);
7113 case NPV_NotNullPointer
:
7117 if (S
.IsQualificationConversion(ResultArg
->getType(),
7118 ParamType
.getNonReferenceType(), false,
7119 ObjCLifetimeConversion
)) {
7120 ResultArg
= S
.ImpCastExprToType(ResultArg
, ParamType
, CK_NoOp
,
7121 ResultArg
->getValueKind())
7123 } else if (!S
.Context
.hasSameUnqualifiedType(
7124 ResultArg
->getType(), ParamType
.getNonReferenceType())) {
7125 // We can't perform this conversion.
7126 S
.Diag(ResultArg
->getBeginLoc(), diag::err_template_arg_not_convertible
)
7127 << ResultArg
->getType() << ParamType
<< ResultArg
->getSourceRange();
7128 S
.NoteTemplateParameterLocation(*Param
);
7133 return S
.Diag(Arg
->getBeginLoc(),
7134 diag::err_template_arg_not_pointer_to_member_form
)
7135 << Arg
->getSourceRange();
7137 if (isa
<FieldDecl
>(DRE
->getDecl()) ||
7138 isa
<IndirectFieldDecl
>(DRE
->getDecl()) ||
7139 isa
<CXXMethodDecl
>(DRE
->getDecl())) {
7140 assert((isa
<FieldDecl
>(DRE
->getDecl()) ||
7141 isa
<IndirectFieldDecl
>(DRE
->getDecl()) ||
7142 cast
<CXXMethodDecl
>(DRE
->getDecl())
7143 ->isImplicitObjectMemberFunction()) &&
7144 "Only non-static member pointers can make it here");
7146 // Okay: this is the address of a non-static member, and therefore
7147 // a member pointer constant.
7148 if (Arg
->isTypeDependent() || Arg
->isValueDependent()) {
7149 SugaredConverted
= TemplateArgument(Arg
);
7150 CanonicalConverted
=
7151 S
.Context
.getCanonicalTemplateArgument(SugaredConverted
);
7153 ValueDecl
*D
= DRE
->getDecl();
7154 SugaredConverted
= TemplateArgument(D
, ParamType
);
7155 CanonicalConverted
=
7156 TemplateArgument(cast
<ValueDecl
>(D
->getCanonicalDecl()),
7157 S
.Context
.getCanonicalType(ParamType
));
7162 // We found something else, but we don't know specifically what it is.
7163 S
.Diag(Arg
->getBeginLoc(), diag::err_template_arg_not_pointer_to_member_form
)
7164 << Arg
->getSourceRange();
7165 S
.Diag(DRE
->getDecl()->getLocation(), diag::note_template_arg_refers_here
);
7169 /// Check a template argument against its corresponding
7170 /// non-type template parameter.
7172 /// This routine implements the semantics of C++ [temp.arg.nontype].
7173 /// If an error occurred, it returns ExprError(); otherwise, it
7174 /// returns the converted template argument. \p ParamType is the
7175 /// type of the non-type template parameter after it has been instantiated.
7176 ExprResult
Sema::CheckTemplateArgument(NonTypeTemplateParmDecl
*Param
,
7177 QualType ParamType
, Expr
*Arg
,
7178 TemplateArgument
&SugaredConverted
,
7179 TemplateArgument
&CanonicalConverted
,
7180 CheckTemplateArgumentKind CTAK
) {
7181 SourceLocation StartLoc
= Arg
->getBeginLoc();
7183 // If the parameter type somehow involves auto, deduce the type now.
7184 DeducedType
*DeducedT
= ParamType
->getContainedDeducedType();
7185 if (getLangOpts().CPlusPlus17
&& DeducedT
&& !DeducedT
->isDeduced()) {
7186 // During template argument deduction, we allow 'decltype(auto)' to
7187 // match an arbitrary dependent argument.
7188 // FIXME: The language rules don't say what happens in this case.
7189 // FIXME: We get an opaque dependent type out of decltype(auto) if the
7190 // expression is merely instantiation-dependent; is this enough?
7191 if (CTAK
== CTAK_Deduced
&& Arg
->isTypeDependent()) {
7192 auto *AT
= dyn_cast
<AutoType
>(DeducedT
);
7193 if (AT
&& AT
->isDecltypeAuto()) {
7194 SugaredConverted
= TemplateArgument(Arg
);
7195 CanonicalConverted
= TemplateArgument(
7196 Context
.getCanonicalTemplateArgument(SugaredConverted
));
7201 // When checking a deduced template argument, deduce from its type even if
7202 // the type is dependent, in order to check the types of non-type template
7203 // arguments line up properly in partial ordering.
7204 Expr
*DeductionArg
= Arg
;
7205 if (auto *PE
= dyn_cast
<PackExpansionExpr
>(DeductionArg
))
7206 DeductionArg
= PE
->getPattern();
7207 TypeSourceInfo
*TSI
=
7208 Context
.getTrivialTypeSourceInfo(ParamType
, Param
->getLocation());
7209 if (isa
<DeducedTemplateSpecializationType
>(DeducedT
)) {
7210 InitializedEntity Entity
=
7211 InitializedEntity::InitializeTemplateParameter(ParamType
, Param
);
7212 InitializationKind Kind
= InitializationKind::CreateForInit(
7213 DeductionArg
->getBeginLoc(), /*DirectInit*/false, DeductionArg
);
7214 Expr
*Inits
[1] = {DeductionArg
};
7216 DeduceTemplateSpecializationFromInitializer(TSI
, Entity
, Kind
, Inits
);
7217 if (ParamType
.isNull())
7220 TemplateDeductionInfo
Info(DeductionArg
->getExprLoc(),
7221 Param
->getDepth() + 1);
7222 ParamType
= QualType();
7223 TemplateDeductionResult Result
=
7224 DeduceAutoType(TSI
->getTypeLoc(), DeductionArg
, ParamType
, Info
,
7225 /*DependentDeduction=*/true,
7226 // We do not check constraints right now because the
7227 // immediately-declared constraint of the auto type is
7228 // also an associated constraint, and will be checked
7229 // along with the other associated constraints after
7230 // checking the template argument list.
7231 /*IgnoreConstraints=*/true);
7232 if (Result
== TDK_AlreadyDiagnosed
) {
7233 if (ParamType
.isNull())
7235 } else if (Result
!= TDK_Success
) {
7236 Diag(Arg
->getExprLoc(),
7237 diag::err_non_type_template_parm_type_deduction_failure
)
7238 << Param
->getDeclName() << Param
->getType() << Arg
->getType()
7239 << Arg
->getSourceRange();
7240 NoteTemplateParameterLocation(*Param
);
7244 // CheckNonTypeTemplateParameterType will produce a diagnostic if there's
7245 // an error. The error message normally references the parameter
7246 // declaration, but here we'll pass the argument location because that's
7247 // where the parameter type is deduced.
7248 ParamType
= CheckNonTypeTemplateParameterType(ParamType
, Arg
->getExprLoc());
7249 if (ParamType
.isNull()) {
7250 NoteTemplateParameterLocation(*Param
);
7255 // We should have already dropped all cv-qualifiers by now.
7256 assert(!ParamType
.hasQualifiers() &&
7257 "non-type template parameter type cannot be qualified");
7259 // FIXME: When Param is a reference, should we check that Arg is an lvalue?
7260 if (CTAK
== CTAK_Deduced
&&
7261 (ParamType
->isReferenceType()
7262 ? !Context
.hasSameType(ParamType
.getNonReferenceType(),
7264 : !Context
.hasSameUnqualifiedType(ParamType
, Arg
->getType()))) {
7265 // FIXME: If either type is dependent, we skip the check. This isn't
7266 // correct, since during deduction we're supposed to have replaced each
7267 // template parameter with some unique (non-dependent) placeholder.
7268 // FIXME: If the argument type contains 'auto', we carry on and fail the
7269 // type check in order to force specific types to be more specialized than
7270 // 'auto'. It's not clear how partial ordering with 'auto' is supposed to
7271 // work. Similarly for CTAD, when comparing 'A<x>' against 'A'.
7272 if ((ParamType
->isDependentType() || Arg
->isTypeDependent()) &&
7273 !Arg
->getType()->getContainedDeducedType()) {
7274 SugaredConverted
= TemplateArgument(Arg
);
7275 CanonicalConverted
= TemplateArgument(
7276 Context
.getCanonicalTemplateArgument(SugaredConverted
));
7279 // FIXME: This attempts to implement C++ [temp.deduct.type]p17. Per DR1770,
7280 // we should actually be checking the type of the template argument in P,
7281 // not the type of the template argument deduced from A, against the
7282 // template parameter type.
7283 Diag(StartLoc
, diag::err_deduced_non_type_template_arg_type_mismatch
)
7285 << ParamType
.getUnqualifiedType();
7286 NoteTemplateParameterLocation(*Param
);
7290 // If either the parameter has a dependent type or the argument is
7291 // type-dependent, there's nothing we can check now.
7292 if (ParamType
->isDependentType() || Arg
->isTypeDependent()) {
7293 // Force the argument to the type of the parameter to maintain invariants.
7294 auto *PE
= dyn_cast
<PackExpansionExpr
>(Arg
);
7296 Arg
= PE
->getPattern();
7297 ExprResult E
= ImpCastExprToType(
7298 Arg
, ParamType
.getNonLValueExprType(Context
), CK_Dependent
,
7299 ParamType
->isLValueReferenceType() ? VK_LValue
7300 : ParamType
->isRValueReferenceType() ? VK_XValue
7305 // Recreate a pack expansion if we unwrapped one.
7307 PackExpansionExpr(E
.get()->getType(), E
.get(), PE
->getEllipsisLoc(),
7308 PE
->getNumExpansions());
7310 SugaredConverted
= TemplateArgument(E
.get());
7311 CanonicalConverted
= TemplateArgument(
7312 Context
.getCanonicalTemplateArgument(SugaredConverted
));
7316 QualType CanonParamType
= Context
.getCanonicalType(ParamType
);
7317 // Avoid making a copy when initializing a template parameter of class type
7318 // from a template parameter object of the same type. This is going beyond
7319 // the standard, but is required for soundness: in
7320 // template<A a> struct X { X *p; X<a> *q; };
7321 // ... we need p and q to have the same type.
7323 // Similarly, don't inject a call to a copy constructor when initializing
7324 // from a template parameter of the same type.
7325 Expr
*InnerArg
= Arg
->IgnoreParenImpCasts();
7326 if (ParamType
->isRecordType() && isa
<DeclRefExpr
>(InnerArg
) &&
7327 Context
.hasSameUnqualifiedType(ParamType
, InnerArg
->getType())) {
7328 NamedDecl
*ND
= cast
<DeclRefExpr
>(InnerArg
)->getDecl();
7329 if (auto *TPO
= dyn_cast
<TemplateParamObjectDecl
>(ND
)) {
7331 SugaredConverted
= TemplateArgument(TPO
, ParamType
);
7332 CanonicalConverted
=
7333 TemplateArgument(TPO
->getCanonicalDecl(), CanonParamType
);
7336 if (isa
<NonTypeTemplateParmDecl
>(ND
)) {
7337 SugaredConverted
= TemplateArgument(Arg
);
7338 CanonicalConverted
=
7339 Context
.getCanonicalTemplateArgument(SugaredConverted
);
7344 // The initialization of the parameter from the argument is
7345 // a constant-evaluated context.
7346 EnterExpressionEvaluationContext
ConstantEvaluated(
7347 *this, Sema::ExpressionEvaluationContext::ConstantEvaluated
);
7349 bool IsConvertedConstantExpression
= true;
7350 if (isa
<InitListExpr
>(Arg
) || ParamType
->isRecordType()) {
7351 InitializationKind Kind
= InitializationKind::CreateForInit(
7352 Arg
->getBeginLoc(), /*DirectInit=*/false, Arg
);
7353 Expr
*Inits
[1] = {Arg
};
7354 InitializedEntity Entity
=
7355 InitializedEntity::InitializeTemplateParameter(ParamType
, Param
);
7356 InitializationSequence
InitSeq(*this, Entity
, Kind
, Inits
);
7357 ExprResult Result
= InitSeq
.Perform(*this, Entity
, Kind
, Inits
);
7358 if (Result
.isInvalid() || !Result
.get())
7360 Result
= ActOnConstantExpression(Result
.get());
7361 if (Result
.isInvalid() || !Result
.get())
7363 Arg
= ActOnFinishFullExpr(Result
.get(), Arg
->getBeginLoc(),
7364 /*DiscardedValue=*/false,
7365 /*IsConstexpr=*/true, /*IsTemplateArgument=*/true)
7367 IsConvertedConstantExpression
= false;
7370 if (getLangOpts().CPlusPlus17
) {
7371 // C++17 [temp.arg.nontype]p1:
7372 // A template-argument for a non-type template parameter shall be
7373 // a converted constant expression of the type of the template-parameter.
7375 ExprResult ArgResult
;
7376 if (IsConvertedConstantExpression
) {
7377 ArgResult
= BuildConvertedConstantExpression(Arg
, ParamType
,
7378 CCEK_TemplateArg
, Param
);
7379 if (ArgResult
.isInvalid())
7385 // For a value-dependent argument, CheckConvertedConstantExpression is
7386 // permitted (and expected) to be unable to determine a value.
7387 if (ArgResult
.get()->isValueDependent()) {
7388 SugaredConverted
= TemplateArgument(ArgResult
.get());
7389 CanonicalConverted
=
7390 Context
.getCanonicalTemplateArgument(SugaredConverted
);
7394 APValue PreNarrowingValue
;
7395 ArgResult
= EvaluateConvertedConstantExpression(
7396 ArgResult
.get(), ParamType
, Value
, CCEK_TemplateArg
, /*RequireInt=*/
7397 false, PreNarrowingValue
);
7398 if (ArgResult
.isInvalid())
7401 // Convert the APValue to a TemplateArgument.
7402 switch (Value
.getKind()) {
7404 assert(ParamType
->isNullPtrType());
7405 SugaredConverted
= TemplateArgument(ParamType
, /*isNullPtr=*/true);
7406 CanonicalConverted
= TemplateArgument(CanonParamType
, /*isNullPtr=*/true);
7408 case APValue::Indeterminate
:
7409 llvm_unreachable("result of constant evaluation should be initialized");
7412 assert(ParamType
->isIntegralOrEnumerationType());
7413 SugaredConverted
= TemplateArgument(Context
, Value
.getInt(), ParamType
);
7414 CanonicalConverted
=
7415 TemplateArgument(Context
, Value
.getInt(), CanonParamType
);
7417 case APValue::MemberPointer
: {
7418 assert(ParamType
->isMemberPointerType());
7420 // FIXME: We need TemplateArgument representation and mangling for these.
7421 if (!Value
.getMemberPointerPath().empty()) {
7422 Diag(Arg
->getBeginLoc(),
7423 diag::err_template_arg_member_ptr_base_derived_not_supported
)
7424 << Value
.getMemberPointerDecl() << ParamType
7425 << Arg
->getSourceRange();
7429 auto *VD
= const_cast<ValueDecl
*>(Value
.getMemberPointerDecl());
7430 SugaredConverted
= VD
? TemplateArgument(VD
, ParamType
)
7431 : TemplateArgument(ParamType
, /*isNullPtr=*/true);
7432 CanonicalConverted
=
7433 VD
? TemplateArgument(cast
<ValueDecl
>(VD
->getCanonicalDecl()),
7435 : TemplateArgument(CanonParamType
, /*isNullPtr=*/true);
7438 case APValue::LValue
: {
7439 // For a non-type template-parameter of pointer or reference type,
7440 // the value of the constant expression shall not refer to
7441 assert(ParamType
->isPointerType() || ParamType
->isReferenceType() ||
7442 ParamType
->isNullPtrType());
7443 // -- a temporary object
7444 // -- a string literal
7445 // -- the result of a typeid expression, or
7446 // -- a predefined __func__ variable
7447 APValue::LValueBase Base
= Value
.getLValueBase();
7448 auto *VD
= const_cast<ValueDecl
*>(Base
.dyn_cast
<const ValueDecl
*>());
7451 isa
<LifetimeExtendedTemporaryDecl
, UnnamedGlobalConstantDecl
>(VD
))) {
7452 Diag(Arg
->getBeginLoc(), diag::err_template_arg_not_decl_ref
)
7453 << Arg
->getSourceRange();
7457 // FIXME: Until C++20
7458 if (Value
.hasLValuePath() && Value
.getLValuePath().size() == 1 &&
7459 VD
&& VD
->getType()->isArrayType() &&
7460 Value
.getLValuePath()[0].getAsArrayIndex() == 0 &&
7461 !Value
.isLValueOnePastTheEnd() && ParamType
->isPointerType()) {
7462 // Per defect report (no number yet):
7463 // ... other than a pointer to the first element of a complete array
7465 } else if (!Value
.hasLValuePath() || Value
.getLValuePath().size() ||
7466 Value
.isLValueOnePastTheEnd()) {
7467 Diag(StartLoc
, diag::err_non_type_template_arg_subobject
)
7468 << Value
.getAsString(Context
, ParamType
);
7471 assert((VD
|| !ParamType
->isReferenceType()) &&
7472 "null reference should not be a constant expression");
7473 assert((!VD
|| !ParamType
->isNullPtrType()) &&
7474 "non-null value of type nullptr_t?");
7476 SugaredConverted
= VD
? TemplateArgument(VD
, ParamType
)
7477 : TemplateArgument(ParamType
, /*isNullPtr=*/true);
7478 CanonicalConverted
=
7479 VD
? TemplateArgument(cast
<ValueDecl
>(VD
->getCanonicalDecl()),
7481 : TemplateArgument(CanonParamType
, /*isNullPtr=*/true);
7484 case APValue::Struct
:
7485 case APValue::Union
: {
7486 // Get or create the corresponding template parameter object.
7487 TemplateParamObjectDecl
*D
=
7488 Context
.getTemplateParamObjectDecl(ParamType
, Value
);
7489 SugaredConverted
= TemplateArgument(D
, ParamType
);
7490 CanonicalConverted
=
7491 TemplateArgument(D
->getCanonicalDecl(), CanonParamType
);
7494 case APValue::AddrLabelDiff
:
7495 return Diag(StartLoc
, diag::err_non_type_template_arg_addr_label_diff
);
7496 case APValue::FixedPoint
:
7497 case APValue::Float
:
7498 case APValue::ComplexInt
:
7499 case APValue::ComplexFloat
:
7500 case APValue::Vector
:
7501 case APValue::Array
:
7502 return Diag(StartLoc
, diag::err_non_type_template_arg_unsupported
)
7506 return ArgResult
.get();
7509 // C++ [temp.arg.nontype]p5:
7510 // The following conversions are performed on each expression used
7511 // as a non-type template-argument. If a non-type
7512 // template-argument cannot be converted to the type of the
7513 // corresponding template-parameter then the program is
7515 if (ParamType
->isIntegralOrEnumerationType()) {
7517 // -- for a non-type template-parameter of integral or
7518 // enumeration type, conversions permitted in a converted
7519 // constant expression are applied.
7522 // -- for a non-type template-parameter of integral or
7523 // enumeration type, integral promotions (4.5) and integral
7524 // conversions (4.7) are applied.
7526 if (getLangOpts().CPlusPlus11
) {
7527 // C++ [temp.arg.nontype]p1:
7528 // A template-argument for a non-type, non-template template-parameter
7531 // -- for a non-type template-parameter of integral or enumeration
7532 // type, a converted constant expression of the type of the
7533 // template-parameter; or
7535 ExprResult ArgResult
=
7536 CheckConvertedConstantExpression(Arg
, ParamType
, Value
,
7538 if (ArgResult
.isInvalid())
7541 // We can't check arbitrary value-dependent arguments.
7542 if (ArgResult
.get()->isValueDependent()) {
7543 SugaredConverted
= TemplateArgument(ArgResult
.get());
7544 CanonicalConverted
=
7545 Context
.getCanonicalTemplateArgument(SugaredConverted
);
7549 // Widen the argument value to sizeof(parameter type). This is almost
7550 // always a no-op, except when the parameter type is bool. In
7551 // that case, this may extend the argument from 1 bit to 8 bits.
7552 QualType IntegerType
= ParamType
;
7553 if (const EnumType
*Enum
= IntegerType
->getAs
<EnumType
>())
7554 IntegerType
= Enum
->getDecl()->getIntegerType();
7555 Value
= Value
.extOrTrunc(IntegerType
->isBitIntType()
7556 ? Context
.getIntWidth(IntegerType
)
7557 : Context
.getTypeSize(IntegerType
));
7559 SugaredConverted
= TemplateArgument(Context
, Value
, ParamType
);
7560 CanonicalConverted
=
7561 TemplateArgument(Context
, Value
, Context
.getCanonicalType(ParamType
));
7565 ExprResult ArgResult
= DefaultLvalueConversion(Arg
);
7566 if (ArgResult
.isInvalid())
7568 Arg
= ArgResult
.get();
7570 QualType ArgType
= Arg
->getType();
7572 // C++ [temp.arg.nontype]p1:
7573 // A template-argument for a non-type, non-template
7574 // template-parameter shall be one of:
7576 // -- an integral constant-expression of integral or enumeration
7578 // -- the name of a non-type template-parameter; or
7580 if (!ArgType
->isIntegralOrEnumerationType()) {
7581 Diag(Arg
->getBeginLoc(), diag::err_template_arg_not_integral_or_enumeral
)
7582 << ArgType
<< Arg
->getSourceRange();
7583 NoteTemplateParameterLocation(*Param
);
7585 } else if (!Arg
->isValueDependent()) {
7586 class TmplArgICEDiagnoser
: public VerifyICEDiagnoser
{
7590 TmplArgICEDiagnoser(QualType T
) : T(T
) { }
7592 SemaDiagnosticBuilder
diagnoseNotICE(Sema
&S
,
7593 SourceLocation Loc
) override
{
7594 return S
.Diag(Loc
, diag::err_template_arg_not_ice
) << T
;
7596 } Diagnoser(ArgType
);
7598 Arg
= VerifyIntegerConstantExpression(Arg
, &Value
, Diagnoser
).get();
7603 // From here on out, all we care about is the unqualified form
7604 // of the argument type.
7605 ArgType
= ArgType
.getUnqualifiedType();
7607 // Try to convert the argument to the parameter's type.
7608 if (Context
.hasSameType(ParamType
, ArgType
)) {
7609 // Okay: no conversion necessary
7610 } else if (ParamType
->isBooleanType()) {
7611 // This is an integral-to-boolean conversion.
7612 Arg
= ImpCastExprToType(Arg
, ParamType
, CK_IntegralToBoolean
).get();
7613 } else if (IsIntegralPromotion(Arg
, ArgType
, ParamType
) ||
7614 !ParamType
->isEnumeralType()) {
7615 // This is an integral promotion or conversion.
7616 Arg
= ImpCastExprToType(Arg
, ParamType
, CK_IntegralCast
).get();
7618 // We can't perform this conversion.
7619 Diag(Arg
->getBeginLoc(), diag::err_template_arg_not_convertible
)
7620 << Arg
->getType() << ParamType
<< Arg
->getSourceRange();
7621 NoteTemplateParameterLocation(*Param
);
7625 // Add the value of this argument to the list of converted
7626 // arguments. We use the bitwidth and signedness of the template
7628 if (Arg
->isValueDependent()) {
7629 // The argument is value-dependent. Create a new
7630 // TemplateArgument with the converted expression.
7631 SugaredConverted
= TemplateArgument(Arg
);
7632 CanonicalConverted
=
7633 Context
.getCanonicalTemplateArgument(SugaredConverted
);
7637 QualType IntegerType
= ParamType
;
7638 if (const EnumType
*Enum
= IntegerType
->getAs
<EnumType
>()) {
7639 IntegerType
= Enum
->getDecl()->getIntegerType();
7642 if (ParamType
->isBooleanType()) {
7643 // Value must be zero or one.
7645 unsigned AllowedBits
= Context
.getTypeSize(IntegerType
);
7646 if (Value
.getBitWidth() != AllowedBits
)
7647 Value
= Value
.extOrTrunc(AllowedBits
);
7648 Value
.setIsSigned(IntegerType
->isSignedIntegerOrEnumerationType());
7650 llvm::APSInt OldValue
= Value
;
7652 // Coerce the template argument's value to the value it will have
7653 // based on the template parameter's type.
7654 unsigned AllowedBits
= IntegerType
->isBitIntType()
7655 ? Context
.getIntWidth(IntegerType
)
7656 : Context
.getTypeSize(IntegerType
);
7657 if (Value
.getBitWidth() != AllowedBits
)
7658 Value
= Value
.extOrTrunc(AllowedBits
);
7659 Value
.setIsSigned(IntegerType
->isSignedIntegerOrEnumerationType());
7661 // Complain if an unsigned parameter received a negative value.
7662 if (IntegerType
->isUnsignedIntegerOrEnumerationType() &&
7663 (OldValue
.isSigned() && OldValue
.isNegative())) {
7664 Diag(Arg
->getBeginLoc(), diag::warn_template_arg_negative
)
7665 << toString(OldValue
, 10) << toString(Value
, 10) << Param
->getType()
7666 << Arg
->getSourceRange();
7667 NoteTemplateParameterLocation(*Param
);
7670 // Complain if we overflowed the template parameter's type.
7671 unsigned RequiredBits
;
7672 if (IntegerType
->isUnsignedIntegerOrEnumerationType())
7673 RequiredBits
= OldValue
.getActiveBits();
7674 else if (OldValue
.isUnsigned())
7675 RequiredBits
= OldValue
.getActiveBits() + 1;
7677 RequiredBits
= OldValue
.getSignificantBits();
7678 if (RequiredBits
> AllowedBits
) {
7679 Diag(Arg
->getBeginLoc(), diag::warn_template_arg_too_large
)
7680 << toString(OldValue
, 10) << toString(Value
, 10) << Param
->getType()
7681 << Arg
->getSourceRange();
7682 NoteTemplateParameterLocation(*Param
);
7686 QualType T
= ParamType
->isEnumeralType() ? ParamType
: IntegerType
;
7687 SugaredConverted
= TemplateArgument(Context
, Value
, T
);
7688 CanonicalConverted
=
7689 TemplateArgument(Context
, Value
, Context
.getCanonicalType(T
));
7693 QualType ArgType
= Arg
->getType();
7694 DeclAccessPair FoundResult
; // temporary for ResolveOverloadedFunction
7696 // Handle pointer-to-function, reference-to-function, and
7697 // pointer-to-member-function all in (roughly) the same way.
7698 if (// -- For a non-type template-parameter of type pointer to
7699 // function, only the function-to-pointer conversion (4.3) is
7700 // applied. If the template-argument represents a set of
7701 // overloaded functions (or a pointer to such), the matching
7702 // function is selected from the set (13.4).
7703 (ParamType
->isPointerType() &&
7704 ParamType
->castAs
<PointerType
>()->getPointeeType()->isFunctionType()) ||
7705 // -- For a non-type template-parameter of type reference to
7706 // function, no conversions apply. If the template-argument
7707 // represents a set of overloaded functions, the matching
7708 // function is selected from the set (13.4).
7709 (ParamType
->isReferenceType() &&
7710 ParamType
->castAs
<ReferenceType
>()->getPointeeType()->isFunctionType()) ||
7711 // -- For a non-type template-parameter of type pointer to
7712 // member function, no conversions apply. If the
7713 // template-argument represents a set of overloaded member
7714 // functions, the matching member function is selected from
7716 (ParamType
->isMemberPointerType() &&
7717 ParamType
->castAs
<MemberPointerType
>()->getPointeeType()
7718 ->isFunctionType())) {
7720 if (Arg
->getType() == Context
.OverloadTy
) {
7721 if (FunctionDecl
*Fn
= ResolveAddressOfOverloadedFunction(Arg
, ParamType
,
7724 if (DiagnoseUseOfDecl(Fn
, Arg
->getBeginLoc()))
7727 ExprResult Res
= FixOverloadedFunctionReference(Arg
, FoundResult
, Fn
);
7728 if (Res
.isInvalid())
7731 ArgType
= Arg
->getType();
7736 if (!ParamType
->isMemberPointerType()) {
7737 if (CheckTemplateArgumentAddressOfObjectOrFunction(
7738 *this, Param
, ParamType
, Arg
, SugaredConverted
,
7739 CanonicalConverted
))
7744 if (CheckTemplateArgumentPointerToMember(
7745 *this, Param
, ParamType
, Arg
, SugaredConverted
, CanonicalConverted
))
7750 if (ParamType
->isPointerType()) {
7751 // -- for a non-type template-parameter of type pointer to
7752 // object, qualification conversions (4.4) and the
7753 // array-to-pointer conversion (4.2) are applied.
7754 // C++0x also allows a value of std::nullptr_t.
7755 assert(ParamType
->getPointeeType()->isIncompleteOrObjectType() &&
7756 "Only object pointers allowed here");
7758 if (CheckTemplateArgumentAddressOfObjectOrFunction(
7759 *this, Param
, ParamType
, Arg
, SugaredConverted
, CanonicalConverted
))
7764 if (const ReferenceType
*ParamRefType
= ParamType
->getAs
<ReferenceType
>()) {
7765 // -- For a non-type template-parameter of type reference to
7766 // object, no conversions apply. The type referred to by the
7767 // reference may be more cv-qualified than the (otherwise
7768 // identical) type of the template-argument. The
7769 // template-parameter is bound directly to the
7770 // template-argument, which must be an lvalue.
7771 assert(ParamRefType
->getPointeeType()->isIncompleteOrObjectType() &&
7772 "Only object references allowed here");
7774 if (Arg
->getType() == Context
.OverloadTy
) {
7775 if (FunctionDecl
*Fn
= ResolveAddressOfOverloadedFunction(Arg
,
7776 ParamRefType
->getPointeeType(),
7779 if (DiagnoseUseOfDecl(Fn
, Arg
->getBeginLoc()))
7781 ExprResult Res
= FixOverloadedFunctionReference(Arg
, FoundResult
, Fn
);
7782 if (Res
.isInvalid())
7785 ArgType
= Arg
->getType();
7790 if (CheckTemplateArgumentAddressOfObjectOrFunction(
7791 *this, Param
, ParamType
, Arg
, SugaredConverted
, CanonicalConverted
))
7796 // Deal with parameters of type std::nullptr_t.
7797 if (ParamType
->isNullPtrType()) {
7798 if (Arg
->isTypeDependent() || Arg
->isValueDependent()) {
7799 SugaredConverted
= TemplateArgument(Arg
);
7800 CanonicalConverted
=
7801 Context
.getCanonicalTemplateArgument(SugaredConverted
);
7805 switch (isNullPointerValueTemplateArgument(*this, Param
, ParamType
, Arg
)) {
7806 case NPV_NotNullPointer
:
7807 Diag(Arg
->getExprLoc(), diag::err_template_arg_not_convertible
)
7808 << Arg
->getType() << ParamType
;
7809 NoteTemplateParameterLocation(*Param
);
7815 case NPV_NullPointer
:
7816 Diag(Arg
->getExprLoc(), diag::warn_cxx98_compat_template_arg_null
);
7817 SugaredConverted
= TemplateArgument(ParamType
,
7818 /*isNullPtr=*/true);
7819 CanonicalConverted
= TemplateArgument(Context
.getCanonicalType(ParamType
),
7820 /*isNullPtr=*/true);
7825 // -- For a non-type template-parameter of type pointer to data
7826 // member, qualification conversions (4.4) are applied.
7827 assert(ParamType
->isMemberPointerType() && "Only pointers to members remain");
7829 if (CheckTemplateArgumentPointerToMember(
7830 *this, Param
, ParamType
, Arg
, SugaredConverted
, CanonicalConverted
))
7835 static void DiagnoseTemplateParameterListArityMismatch(
7836 Sema
&S
, TemplateParameterList
*New
, TemplateParameterList
*Old
,
7837 Sema::TemplateParameterListEqualKind Kind
, SourceLocation TemplateArgLoc
);
7839 /// Check a template argument against its corresponding
7840 /// template template parameter.
7842 /// This routine implements the semantics of C++ [temp.arg.template].
7843 /// It returns true if an error occurred, and false otherwise.
7844 bool Sema::CheckTemplateTemplateArgument(TemplateTemplateParmDecl
*Param
,
7845 TemplateParameterList
*Params
,
7846 TemplateArgumentLoc
&Arg
) {
7847 TemplateName Name
= Arg
.getArgument().getAsTemplateOrTemplatePattern();
7848 TemplateDecl
*Template
= Name
.getAsTemplateDecl();
7850 // Any dependent template name is fine.
7851 assert(Name
.isDependent() && "Non-dependent template isn't a declaration?");
7855 if (Template
->isInvalidDecl())
7858 // C++0x [temp.arg.template]p1:
7859 // A template-argument for a template template-parameter shall be
7860 // the name of a class template or an alias template, expressed as an
7861 // id-expression. When the template-argument names a class template, only
7862 // primary class templates are considered when matching the
7863 // template template argument with the corresponding parameter;
7864 // partial specializations are not considered even if their
7865 // parameter lists match that of the template template parameter.
7867 // Note that we also allow template template parameters here, which
7868 // will happen when we are dealing with, e.g., class template
7869 // partial specializations.
7870 if (!isa
<ClassTemplateDecl
>(Template
) &&
7871 !isa
<TemplateTemplateParmDecl
>(Template
) &&
7872 !isa
<TypeAliasTemplateDecl
>(Template
) &&
7873 !isa
<BuiltinTemplateDecl
>(Template
)) {
7874 assert(isa
<FunctionTemplateDecl
>(Template
) &&
7875 "Only function templates are possible here");
7876 Diag(Arg
.getLocation(), diag::err_template_arg_not_valid_template
);
7877 Diag(Template
->getLocation(), diag::note_template_arg_refers_here_func
)
7881 // C++1z [temp.arg.template]p3: (DR 150)
7882 // A template-argument matches a template template-parameter P when P
7883 // is at least as specialized as the template-argument A.
7884 // FIXME: We should enable RelaxedTemplateTemplateArgs by default as it is a
7885 // defect report resolution from C++17 and shouldn't be introduced by
7887 if (getLangOpts().RelaxedTemplateTemplateArgs
) {
7888 // Quick check for the common case:
7889 // If P contains a parameter pack, then A [...] matches P if each of A's
7890 // template parameters matches the corresponding template parameter in
7891 // the template-parameter-list of P.
7892 if (TemplateParameterListsAreEqual(
7893 Template
->getTemplateParameters(), Params
, false,
7894 TPL_TemplateTemplateArgumentMatch
, Arg
.getLocation()) &&
7895 // If the argument has no associated constraints, then the parameter is
7896 // definitely at least as specialized as the argument.
7897 // Otherwise - we need a more thorough check.
7898 !Template
->hasAssociatedConstraints())
7901 if (isTemplateTemplateParameterAtLeastAsSpecializedAs(Params
, Template
,
7902 Arg
.getLocation())) {
7904 // C++20[temp.func.order]p2
7905 // [...] If both deductions succeed, the partial ordering selects the
7906 // more constrained template (if one exists) as determined below.
7907 SmallVector
<const Expr
*, 3> ParamsAC
, TemplateAC
;
7908 Params
->getAssociatedConstraints(ParamsAC
);
7909 // C++2a[temp.arg.template]p3
7910 // [...] In this comparison, if P is unconstrained, the constraints on A
7911 // are not considered.
7912 if (ParamsAC
.empty())
7915 Template
->getAssociatedConstraints(TemplateAC
);
7917 bool IsParamAtLeastAsConstrained
;
7918 if (IsAtLeastAsConstrained(Param
, ParamsAC
, Template
, TemplateAC
,
7919 IsParamAtLeastAsConstrained
))
7921 if (!IsParamAtLeastAsConstrained
) {
7922 Diag(Arg
.getLocation(),
7923 diag::err_template_template_parameter_not_at_least_as_constrained
)
7924 << Template
<< Param
<< Arg
.getSourceRange();
7925 Diag(Param
->getLocation(), diag::note_entity_declared_at
) << Param
;
7926 Diag(Template
->getLocation(), diag::note_entity_declared_at
)
7928 MaybeEmitAmbiguousAtomicConstraintsDiagnostic(Param
, ParamsAC
, Template
,
7934 // FIXME: Produce better diagnostics for deduction failures.
7937 return !TemplateParameterListsAreEqual(Template
->getTemplateParameters(),
7940 TPL_TemplateTemplateArgumentMatch
,
7944 static Sema::SemaDiagnosticBuilder
noteLocation(Sema
&S
, const NamedDecl
&Decl
,
7945 unsigned HereDiagID
,
7946 unsigned ExternalDiagID
) {
7947 if (Decl
.getLocation().isValid())
7948 return S
.Diag(Decl
.getLocation(), HereDiagID
);
7950 SmallString
<128> Str
;
7951 llvm::raw_svector_ostream
Out(Str
);
7952 PrintingPolicy PP
= S
.getPrintingPolicy();
7954 Decl
.print(Out
, PP
);
7955 return S
.Diag(Decl
.getLocation(), ExternalDiagID
) << Out
.str();
7958 void Sema::NoteTemplateLocation(const NamedDecl
&Decl
,
7959 std::optional
<SourceRange
> ParamRange
) {
7960 SemaDiagnosticBuilder DB
=
7961 noteLocation(*this, Decl
, diag::note_template_decl_here
,
7962 diag::note_template_decl_external
);
7963 if (ParamRange
&& ParamRange
->isValid()) {
7964 assert(Decl
.getLocation().isValid() &&
7965 "Parameter range has location when Decl does not");
7970 void Sema::NoteTemplateParameterLocation(const NamedDecl
&Decl
) {
7971 noteLocation(*this, Decl
, diag::note_template_param_here
,
7972 diag::note_template_param_external
);
7975 /// Given a non-type template argument that refers to a
7976 /// declaration and the type of its corresponding non-type template
7977 /// parameter, produce an expression that properly refers to that
7980 Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument
&Arg
,
7982 SourceLocation Loc
) {
7983 // C++ [temp.param]p8:
7985 // A non-type template-parameter of type "array of T" or
7986 // "function returning T" is adjusted to be of type "pointer to
7987 // T" or "pointer to function returning T", respectively.
7988 if (ParamType
->isArrayType())
7989 ParamType
= Context
.getArrayDecayedType(ParamType
);
7990 else if (ParamType
->isFunctionType())
7991 ParamType
= Context
.getPointerType(ParamType
);
7993 // For a NULL non-type template argument, return nullptr casted to the
7994 // parameter's type.
7995 if (Arg
.getKind() == TemplateArgument::NullPtr
) {
7996 return ImpCastExprToType(
7997 new (Context
) CXXNullPtrLiteralExpr(Context
.NullPtrTy
, Loc
),
7999 ParamType
->getAs
<MemberPointerType
>()
8000 ? CK_NullToMemberPointer
8001 : CK_NullToPointer
);
8003 assert(Arg
.getKind() == TemplateArgument::Declaration
&&
8004 "Only declaration template arguments permitted here");
8006 ValueDecl
*VD
= Arg
.getAsDecl();
8009 if (ParamType
->isMemberPointerType()) {
8010 // If this is a pointer to member, we need to use a qualified name to
8011 // form a suitable pointer-to-member constant.
8012 assert(VD
->getDeclContext()->isRecord() &&
8013 (isa
<CXXMethodDecl
>(VD
) || isa
<FieldDecl
>(VD
) ||
8014 isa
<IndirectFieldDecl
>(VD
)));
8016 = Context
.getTypeDeclType(cast
<RecordDecl
>(VD
->getDeclContext()));
8017 NestedNameSpecifier
*Qualifier
8018 = NestedNameSpecifier::Create(Context
, nullptr, false,
8019 ClassType
.getTypePtr());
8020 SS
.MakeTrivial(Context
, Qualifier
, Loc
);
8023 ExprResult RefExpr
= BuildDeclarationNameExpr(
8024 SS
, DeclarationNameInfo(VD
->getDeclName(), Loc
), VD
);
8025 if (RefExpr
.isInvalid())
8028 // For a pointer, the argument declaration is the pointee. Take its address.
8029 QualType
ElemT(RefExpr
.get()->getType()->getArrayElementTypeNoTypeQual(), 0);
8030 if (ParamType
->isPointerType() && !ElemT
.isNull() &&
8031 Context
.hasSimilarType(ElemT
, ParamType
->getPointeeType())) {
8032 // Decay an array argument if we want a pointer to its first element.
8033 RefExpr
= DefaultFunctionArrayConversion(RefExpr
.get());
8034 if (RefExpr
.isInvalid())
8036 } else if (ParamType
->isPointerType() || ParamType
->isMemberPointerType()) {
8037 // For any other pointer, take the address (or form a pointer-to-member).
8038 RefExpr
= CreateBuiltinUnaryOp(Loc
, UO_AddrOf
, RefExpr
.get());
8039 if (RefExpr
.isInvalid())
8041 } else if (ParamType
->isRecordType()) {
8042 assert(isa
<TemplateParamObjectDecl
>(VD
) &&
8043 "arg for class template param not a template parameter object");
8044 // No conversions apply in this case.
8047 assert(ParamType
->isReferenceType() &&
8048 "unexpected type for decl template argument");
8051 // At this point we should have the right value category.
8052 assert(ParamType
->isReferenceType() == RefExpr
.get()->isLValue() &&
8053 "value kind mismatch for non-type template argument");
8055 // The type of the template parameter can differ from the type of the
8056 // argument in various ways; convert it now if necessary.
8057 QualType DestExprType
= ParamType
.getNonLValueExprType(Context
);
8058 if (!Context
.hasSameType(RefExpr
.get()->getType(), DestExprType
)) {
8061 if (Context
.hasSimilarType(RefExpr
.get()->getType(), DestExprType
) ||
8062 IsFunctionConversion(RefExpr
.get()->getType(), DestExprType
, Ignored
)) {
8064 } else if (ParamType
->isVoidPointerType() &&
8065 RefExpr
.get()->getType()->isPointerType()) {
8068 // FIXME: Pointers to members can need conversion derived-to-base or
8069 // base-to-derived conversions. We currently don't retain enough
8070 // information to convert properly (we need to track a cast path or
8071 // subobject number in the template argument).
8073 "unexpected conversion required for non-type template argument");
8075 RefExpr
= ImpCastExprToType(RefExpr
.get(), DestExprType
, CK
,
8076 RefExpr
.get()->getValueKind());
8082 /// Construct a new expression that refers to the given
8083 /// integral template argument with the given source-location
8086 /// This routine takes care of the mapping from an integral template
8087 /// argument (which may have any integral type) to the appropriate
8090 Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument
&Arg
,
8091 SourceLocation Loc
) {
8092 assert(Arg
.getKind() == TemplateArgument::Integral
&&
8093 "Operation is only valid for integral template arguments");
8094 QualType OrigT
= Arg
.getIntegralType();
8096 // If this is an enum type that we're instantiating, we need to use an integer
8097 // type the same size as the enumerator. We don't want to build an
8098 // IntegerLiteral with enum type. The integer type of an enum type can be of
8099 // any integral type with C++11 enum classes, make sure we create the right
8100 // type of literal for it.
8102 if (const EnumType
*ET
= OrigT
->getAs
<EnumType
>())
8103 T
= ET
->getDecl()->getIntegerType();
8106 if (T
->isAnyCharacterType()) {
8107 CharacterLiteralKind Kind
;
8108 if (T
->isWideCharType())
8109 Kind
= CharacterLiteralKind::Wide
;
8110 else if (T
->isChar8Type() && getLangOpts().Char8
)
8111 Kind
= CharacterLiteralKind::UTF8
;
8112 else if (T
->isChar16Type())
8113 Kind
= CharacterLiteralKind::UTF16
;
8114 else if (T
->isChar32Type())
8115 Kind
= CharacterLiteralKind::UTF32
;
8117 Kind
= CharacterLiteralKind::Ascii
;
8119 E
= new (Context
) CharacterLiteral(Arg
.getAsIntegral().getZExtValue(),
8121 } else if (T
->isBooleanType()) {
8122 E
= CXXBoolLiteralExpr::Create(Context
, Arg
.getAsIntegral().getBoolValue(),
8124 } else if (T
->isNullPtrType()) {
8125 E
= new (Context
) CXXNullPtrLiteralExpr(Context
.NullPtrTy
, Loc
);
8127 E
= IntegerLiteral::Create(Context
, Arg
.getAsIntegral(), T
, Loc
);
8130 if (OrigT
->isEnumeralType()) {
8131 // FIXME: This is a hack. We need a better way to handle substituted
8132 // non-type template parameters.
8133 E
= CStyleCastExpr::Create(Context
, OrigT
, VK_PRValue
, CK_IntegralCast
, E
,
8134 nullptr, CurFPFeatureOverrides(),
8135 Context
.getTrivialTypeSourceInfo(OrigT
, Loc
),
8142 /// Match two template parameters within template parameter lists.
8143 static bool MatchTemplateParameterKind(
8144 Sema
&S
, NamedDecl
*New
,
8145 const Sema::TemplateCompareNewDeclInfo
&NewInstFrom
, NamedDecl
*Old
,
8146 const NamedDecl
*OldInstFrom
, bool Complain
,
8147 Sema::TemplateParameterListEqualKind Kind
, SourceLocation TemplateArgLoc
) {
8148 // Check the actual kind (type, non-type, template).
8149 if (Old
->getKind() != New
->getKind()) {
8151 unsigned NextDiag
= diag::err_template_param_different_kind
;
8152 if (TemplateArgLoc
.isValid()) {
8153 S
.Diag(TemplateArgLoc
, diag::err_template_arg_template_params_mismatch
);
8154 NextDiag
= diag::note_template_param_different_kind
;
8156 S
.Diag(New
->getLocation(), NextDiag
)
8157 << (Kind
!= Sema::TPL_TemplateMatch
);
8158 S
.Diag(Old
->getLocation(), diag::note_template_prev_declaration
)
8159 << (Kind
!= Sema::TPL_TemplateMatch
);
8165 // Check that both are parameter packs or neither are parameter packs.
8166 // However, if we are matching a template template argument to a
8167 // template template parameter, the template template parameter can have
8168 // a parameter pack where the template template argument does not.
8169 if (Old
->isTemplateParameterPack() != New
->isTemplateParameterPack() &&
8170 !(Kind
== Sema::TPL_TemplateTemplateArgumentMatch
&&
8171 Old
->isTemplateParameterPack())) {
8173 unsigned NextDiag
= diag::err_template_parameter_pack_non_pack
;
8174 if (TemplateArgLoc
.isValid()) {
8175 S
.Diag(TemplateArgLoc
,
8176 diag::err_template_arg_template_params_mismatch
);
8177 NextDiag
= diag::note_template_parameter_pack_non_pack
;
8180 unsigned ParamKind
= isa
<TemplateTypeParmDecl
>(New
)? 0
8181 : isa
<NonTypeTemplateParmDecl
>(New
)? 1
8183 S
.Diag(New
->getLocation(), NextDiag
)
8184 << ParamKind
<< New
->isParameterPack();
8185 S
.Diag(Old
->getLocation(), diag::note_template_parameter_pack_here
)
8186 << ParamKind
<< Old
->isParameterPack();
8192 // For non-type template parameters, check the type of the parameter.
8193 if (NonTypeTemplateParmDecl
*OldNTTP
8194 = dyn_cast
<NonTypeTemplateParmDecl
>(Old
)) {
8195 NonTypeTemplateParmDecl
*NewNTTP
= cast
<NonTypeTemplateParmDecl
>(New
);
8197 // If we are matching a template template argument to a template
8198 // template parameter and one of the non-type template parameter types
8199 // is dependent, then we must wait until template instantiation time
8200 // to actually compare the arguments.
8201 if (Kind
!= Sema::TPL_TemplateTemplateArgumentMatch
||
8202 (!OldNTTP
->getType()->isDependentType() &&
8203 !NewNTTP
->getType()->isDependentType())) {
8204 // C++20 [temp.over.link]p6:
8205 // Two [non-type] template-parameters are equivalent [if] they have
8206 // equivalent types ignoring the use of type-constraints for
8207 // placeholder types
8208 QualType OldType
= S
.Context
.getUnconstrainedType(OldNTTP
->getType());
8209 QualType NewType
= S
.Context
.getUnconstrainedType(NewNTTP
->getType());
8210 if (!S
.Context
.hasSameType(OldType
, NewType
)) {
8212 unsigned NextDiag
= diag::err_template_nontype_parm_different_type
;
8213 if (TemplateArgLoc
.isValid()) {
8214 S
.Diag(TemplateArgLoc
,
8215 diag::err_template_arg_template_params_mismatch
);
8216 NextDiag
= diag::note_template_nontype_parm_different_type
;
8218 S
.Diag(NewNTTP
->getLocation(), NextDiag
)
8219 << NewNTTP
->getType()
8220 << (Kind
!= Sema::TPL_TemplateMatch
);
8221 S
.Diag(OldNTTP
->getLocation(),
8222 diag::note_template_nontype_parm_prev_declaration
)
8223 << OldNTTP
->getType();
8230 // For template template parameters, check the template parameter types.
8231 // The template parameter lists of template template
8232 // parameters must agree.
8233 else if (TemplateTemplateParmDecl
*OldTTP
=
8234 dyn_cast
<TemplateTemplateParmDecl
>(Old
)) {
8235 TemplateTemplateParmDecl
*NewTTP
= cast
<TemplateTemplateParmDecl
>(New
);
8236 if (!S
.TemplateParameterListsAreEqual(
8237 NewInstFrom
, NewTTP
->getTemplateParameters(), OldInstFrom
,
8238 OldTTP
->getTemplateParameters(), Complain
,
8239 (Kind
== Sema::TPL_TemplateMatch
8240 ? Sema::TPL_TemplateTemplateParmMatch
8246 if (Kind
!= Sema::TPL_TemplateParamsEquivalent
&&
8247 Kind
!= Sema::TPL_TemplateTemplateArgumentMatch
&&
8248 !isa
<TemplateTemplateParmDecl
>(Old
)) {
8249 const Expr
*NewC
= nullptr, *OldC
= nullptr;
8251 if (isa
<TemplateTypeParmDecl
>(New
)) {
8252 if (const auto *TC
= cast
<TemplateTypeParmDecl
>(New
)->getTypeConstraint())
8253 NewC
= TC
->getImmediatelyDeclaredConstraint();
8254 if (const auto *TC
= cast
<TemplateTypeParmDecl
>(Old
)->getTypeConstraint())
8255 OldC
= TC
->getImmediatelyDeclaredConstraint();
8256 } else if (isa
<NonTypeTemplateParmDecl
>(New
)) {
8257 if (const Expr
*E
= cast
<NonTypeTemplateParmDecl
>(New
)
8258 ->getPlaceholderTypeConstraint())
8260 if (const Expr
*E
= cast
<NonTypeTemplateParmDecl
>(Old
)
8261 ->getPlaceholderTypeConstraint())
8264 llvm_unreachable("unexpected template parameter type");
8266 auto Diagnose
= [&] {
8267 S
.Diag(NewC
? NewC
->getBeginLoc() : New
->getBeginLoc(),
8268 diag::err_template_different_type_constraint
);
8269 S
.Diag(OldC
? OldC
->getBeginLoc() : Old
->getBeginLoc(),
8270 diag::note_template_prev_declaration
) << /*declaration*/0;
8273 if (!NewC
!= !OldC
) {
8280 if (!S
.AreConstraintExpressionsEqual(OldInstFrom
, OldC
, NewInstFrom
,
8292 /// Diagnose a known arity mismatch when comparing template argument
8295 void DiagnoseTemplateParameterListArityMismatch(Sema
&S
,
8296 TemplateParameterList
*New
,
8297 TemplateParameterList
*Old
,
8298 Sema::TemplateParameterListEqualKind Kind
,
8299 SourceLocation TemplateArgLoc
) {
8300 unsigned NextDiag
= diag::err_template_param_list_different_arity
;
8301 if (TemplateArgLoc
.isValid()) {
8302 S
.Diag(TemplateArgLoc
, diag::err_template_arg_template_params_mismatch
);
8303 NextDiag
= diag::note_template_param_list_different_arity
;
8305 S
.Diag(New
->getTemplateLoc(), NextDiag
)
8306 << (New
->size() > Old
->size())
8307 << (Kind
!= Sema::TPL_TemplateMatch
)
8308 << SourceRange(New
->getTemplateLoc(), New
->getRAngleLoc());
8309 S
.Diag(Old
->getTemplateLoc(), diag::note_template_prev_declaration
)
8310 << (Kind
!= Sema::TPL_TemplateMatch
)
8311 << SourceRange(Old
->getTemplateLoc(), Old
->getRAngleLoc());
8314 /// Determine whether the given template parameter lists are
8317 /// \param New The new template parameter list, typically written in the
8318 /// source code as part of a new template declaration.
8320 /// \param Old The old template parameter list, typically found via
8321 /// name lookup of the template declared with this template parameter
8324 /// \param Complain If true, this routine will produce a diagnostic if
8325 /// the template parameter lists are not equivalent.
8327 /// \param Kind describes how we are to match the template parameter lists.
8329 /// \param TemplateArgLoc If this source location is valid, then we
8330 /// are actually checking the template parameter list of a template
8331 /// argument (New) against the template parameter list of its
8332 /// corresponding template template parameter (Old). We produce
8333 /// slightly different diagnostics in this scenario.
8335 /// \returns True if the template parameter lists are equal, false
8337 bool Sema::TemplateParameterListsAreEqual(
8338 const TemplateCompareNewDeclInfo
&NewInstFrom
, TemplateParameterList
*New
,
8339 const NamedDecl
*OldInstFrom
, TemplateParameterList
*Old
, bool Complain
,
8340 TemplateParameterListEqualKind Kind
, SourceLocation TemplateArgLoc
) {
8341 if (Old
->size() != New
->size() && Kind
!= TPL_TemplateTemplateArgumentMatch
) {
8343 DiagnoseTemplateParameterListArityMismatch(*this, New
, Old
, Kind
,
8349 // C++0x [temp.arg.template]p3:
8350 // A template-argument matches a template template-parameter (call it P)
8351 // when each of the template parameters in the template-parameter-list of
8352 // the template-argument's corresponding class template or alias template
8353 // (call it A) matches the corresponding template parameter in the
8354 // template-parameter-list of P. [...]
8355 TemplateParameterList::iterator NewParm
= New
->begin();
8356 TemplateParameterList::iterator NewParmEnd
= New
->end();
8357 for (TemplateParameterList::iterator OldParm
= Old
->begin(),
8358 OldParmEnd
= Old
->end();
8359 OldParm
!= OldParmEnd
; ++OldParm
) {
8360 if (Kind
!= TPL_TemplateTemplateArgumentMatch
||
8361 !(*OldParm
)->isTemplateParameterPack()) {
8362 if (NewParm
== NewParmEnd
) {
8364 DiagnoseTemplateParameterListArityMismatch(*this, New
, Old
, Kind
,
8370 if (!MatchTemplateParameterKind(*this, *NewParm
, NewInstFrom
, *OldParm
,
8371 OldInstFrom
, Complain
, Kind
,
8379 // C++0x [temp.arg.template]p3:
8380 // [...] When P's template- parameter-list contains a template parameter
8381 // pack (14.5.3), the template parameter pack will match zero or more
8382 // template parameters or template parameter packs in the
8383 // template-parameter-list of A with the same type and form as the
8384 // template parameter pack in P (ignoring whether those template
8385 // parameters are template parameter packs).
8386 for (; NewParm
!= NewParmEnd
; ++NewParm
) {
8387 if (!MatchTemplateParameterKind(*this, *NewParm
, NewInstFrom
, *OldParm
,
8388 OldInstFrom
, Complain
, Kind
,
8394 // Make sure we exhausted all of the arguments.
8395 if (NewParm
!= NewParmEnd
) {
8397 DiagnoseTemplateParameterListArityMismatch(*this, New
, Old
, Kind
,
8403 if (Kind
!= TPL_TemplateTemplateArgumentMatch
&&
8404 Kind
!= TPL_TemplateParamsEquivalent
) {
8405 const Expr
*NewRC
= New
->getRequiresClause();
8406 const Expr
*OldRC
= Old
->getRequiresClause();
8408 auto Diagnose
= [&] {
8409 Diag(NewRC
? NewRC
->getBeginLoc() : New
->getTemplateLoc(),
8410 diag::err_template_different_requires_clause
);
8411 Diag(OldRC
? OldRC
->getBeginLoc() : Old
->getTemplateLoc(),
8412 diag::note_template_prev_declaration
) << /*declaration*/0;
8415 if (!NewRC
!= !OldRC
) {
8422 if (!AreConstraintExpressionsEqual(OldInstFrom
, OldRC
, NewInstFrom
,
8434 /// Check whether a template can be declared within this scope.
8436 /// If the template declaration is valid in this scope, returns
8437 /// false. Otherwise, issues a diagnostic and returns true.
8439 Sema::CheckTemplateDeclScope(Scope
*S
, TemplateParameterList
*TemplateParams
) {
8443 // Find the nearest enclosing declaration scope.
8444 while ((S
->getFlags() & Scope::DeclScope
) == 0 ||
8445 (S
->getFlags() & Scope::TemplateParamScope
) != 0)
8448 // C++ [temp.pre]p6: [P2096]
8449 // A template, explicit specialization, or partial specialization shall not
8451 DeclContext
*Ctx
= S
->getEntity();
8452 if (Ctx
&& Ctx
->isExternCContext()) {
8453 Diag(TemplateParams
->getTemplateLoc(), diag::err_template_linkage
)
8454 << TemplateParams
->getSourceRange();
8455 if (const LinkageSpecDecl
*LSD
= Ctx
->getExternCContext())
8456 Diag(LSD
->getExternLoc(), diag::note_extern_c_begins_here
);
8459 Ctx
= Ctx
? Ctx
->getRedeclContext() : nullptr;
8462 // A template-declaration can appear only as a namespace scope or
8463 // class scope declaration.
8464 // C++ [temp.expl.spec]p3:
8465 // An explicit specialization may be declared in any scope in which the
8466 // corresponding primary template may be defined.
8467 // C++ [temp.class.spec]p6: [P2096]
8468 // A partial specialization may be declared in any scope in which the
8469 // corresponding primary template may be defined.
8471 if (Ctx
->isFileContext())
8473 if (CXXRecordDecl
*RD
= dyn_cast
<CXXRecordDecl
>(Ctx
)) {
8474 // C++ [temp.mem]p2:
8475 // A local class shall not have member templates.
8476 if (RD
->isLocalClass())
8477 return Diag(TemplateParams
->getTemplateLoc(),
8478 diag::err_template_inside_local_class
)
8479 << TemplateParams
->getSourceRange();
8485 return Diag(TemplateParams
->getTemplateLoc(),
8486 diag::err_template_outside_namespace_or_class_scope
)
8487 << TemplateParams
->getSourceRange();
8490 /// Determine what kind of template specialization the given declaration
8492 static TemplateSpecializationKind
getTemplateSpecializationKind(Decl
*D
) {
8494 return TSK_Undeclared
;
8496 if (CXXRecordDecl
*Record
= dyn_cast
<CXXRecordDecl
>(D
))
8497 return Record
->getTemplateSpecializationKind();
8498 if (FunctionDecl
*Function
= dyn_cast
<FunctionDecl
>(D
))
8499 return Function
->getTemplateSpecializationKind();
8500 if (VarDecl
*Var
= dyn_cast
<VarDecl
>(D
))
8501 return Var
->getTemplateSpecializationKind();
8503 return TSK_Undeclared
;
8506 /// Check whether a specialization is well-formed in the current
8509 /// This routine determines whether a template specialization can be declared
8510 /// in the current context (C++ [temp.expl.spec]p2).
8512 /// \param S the semantic analysis object for which this check is being
8515 /// \param Specialized the entity being specialized or instantiated, which
8516 /// may be a kind of template (class template, function template, etc.) or
8517 /// a member of a class template (member function, static data member,
8520 /// \param PrevDecl the previous declaration of this entity, if any.
8522 /// \param Loc the location of the explicit specialization or instantiation of
8525 /// \param IsPartialSpecialization whether this is a partial specialization of
8526 /// a class template.
8528 /// \returns true if there was an error that we cannot recover from, false
8530 static bool CheckTemplateSpecializationScope(Sema
&S
,
8531 NamedDecl
*Specialized
,
8532 NamedDecl
*PrevDecl
,
8534 bool IsPartialSpecialization
) {
8535 // Keep these "kind" numbers in sync with the %select statements in the
8536 // various diagnostics emitted by this routine.
8538 if (isa
<ClassTemplateDecl
>(Specialized
))
8539 EntityKind
= IsPartialSpecialization
? 1 : 0;
8540 else if (isa
<VarTemplateDecl
>(Specialized
))
8541 EntityKind
= IsPartialSpecialization
? 3 : 2;
8542 else if (isa
<FunctionTemplateDecl
>(Specialized
))
8544 else if (isa
<CXXMethodDecl
>(Specialized
))
8546 else if (isa
<VarDecl
>(Specialized
))
8548 else if (isa
<RecordDecl
>(Specialized
))
8550 else if (isa
<EnumDecl
>(Specialized
) && S
.getLangOpts().CPlusPlus11
)
8553 S
.Diag(Loc
, diag::err_template_spec_unknown_kind
)
8554 << S
.getLangOpts().CPlusPlus11
;
8555 S
.Diag(Specialized
->getLocation(), diag::note_specialized_entity
);
8559 // C++ [temp.expl.spec]p2:
8560 // An explicit specialization may be declared in any scope in which
8561 // the corresponding primary template may be defined.
8562 if (S
.CurContext
->getRedeclContext()->isFunctionOrMethod()) {
8563 S
.Diag(Loc
, diag::err_template_spec_decl_function_scope
)
8568 // C++ [temp.class.spec]p6:
8569 // A class template partial specialization may be declared in any
8570 // scope in which the primary template may be defined.
8571 DeclContext
*SpecializedContext
=
8572 Specialized
->getDeclContext()->getRedeclContext();
8573 DeclContext
*DC
= S
.CurContext
->getRedeclContext();
8575 // Make sure that this redeclaration (or definition) occurs in the same
8576 // scope or an enclosing namespace.
8577 if (!(DC
->isFileContext() ? DC
->Encloses(SpecializedContext
)
8578 : DC
->Equals(SpecializedContext
))) {
8579 if (isa
<TranslationUnitDecl
>(SpecializedContext
))
8580 S
.Diag(Loc
, diag::err_template_spec_redecl_global_scope
)
8581 << EntityKind
<< Specialized
;
8583 auto *ND
= cast
<NamedDecl
>(SpecializedContext
);
8584 int Diag
= diag::err_template_spec_redecl_out_of_scope
;
8585 if (S
.getLangOpts().MicrosoftExt
&& !DC
->isRecord())
8586 Diag
= diag::ext_ms_template_spec_redecl_out_of_scope
;
8587 S
.Diag(Loc
, Diag
) << EntityKind
<< Specialized
8588 << ND
<< isa
<CXXRecordDecl
>(ND
);
8591 S
.Diag(Specialized
->getLocation(), diag::note_specialized_entity
);
8593 // Don't allow specializing in the wrong class during error recovery.
8594 // Otherwise, things can go horribly wrong.
8602 static SourceRange
findTemplateParameterInType(unsigned Depth
, Expr
*E
) {
8603 if (!E
->isTypeDependent())
8604 return SourceLocation();
8605 DependencyChecker
Checker(Depth
, /*IgnoreNonTypeDependent*/true);
8606 Checker
.TraverseStmt(E
);
8607 if (Checker
.MatchLoc
.isInvalid())
8608 return E
->getSourceRange();
8609 return Checker
.MatchLoc
;
8612 static SourceRange
findTemplateParameter(unsigned Depth
, TypeLoc TL
) {
8613 if (!TL
.getType()->isDependentType())
8614 return SourceLocation();
8615 DependencyChecker
Checker(Depth
, /*IgnoreNonTypeDependent*/true);
8616 Checker
.TraverseTypeLoc(TL
);
8617 if (Checker
.MatchLoc
.isInvalid())
8618 return TL
.getSourceRange();
8619 return Checker
.MatchLoc
;
8622 /// Subroutine of Sema::CheckTemplatePartialSpecializationArgs
8623 /// that checks non-type template partial specialization arguments.
8624 static bool CheckNonTypeTemplatePartialSpecializationArgs(
8625 Sema
&S
, SourceLocation TemplateNameLoc
, NonTypeTemplateParmDecl
*Param
,
8626 const TemplateArgument
*Args
, unsigned NumArgs
, bool IsDefaultArgument
) {
8627 for (unsigned I
= 0; I
!= NumArgs
; ++I
) {
8628 if (Args
[I
].getKind() == TemplateArgument::Pack
) {
8629 if (CheckNonTypeTemplatePartialSpecializationArgs(
8630 S
, TemplateNameLoc
, Param
, Args
[I
].pack_begin(),
8631 Args
[I
].pack_size(), IsDefaultArgument
))
8637 if (Args
[I
].getKind() != TemplateArgument::Expression
)
8640 Expr
*ArgExpr
= Args
[I
].getAsExpr();
8642 // We can have a pack expansion of any of the bullets below.
8643 if (PackExpansionExpr
*Expansion
= dyn_cast
<PackExpansionExpr
>(ArgExpr
))
8644 ArgExpr
= Expansion
->getPattern();
8646 // Strip off any implicit casts we added as part of type checking.
8647 while (ImplicitCastExpr
*ICE
= dyn_cast
<ImplicitCastExpr
>(ArgExpr
))
8648 ArgExpr
= ICE
->getSubExpr();
8650 // C++ [temp.class.spec]p8:
8651 // A non-type argument is non-specialized if it is the name of a
8652 // non-type parameter. All other non-type arguments are
8655 // Below, we check the two conditions that only apply to
8656 // specialized non-type arguments, so skip any non-specialized
8658 if (DeclRefExpr
*DRE
= dyn_cast
<DeclRefExpr
>(ArgExpr
))
8659 if (isa
<NonTypeTemplateParmDecl
>(DRE
->getDecl()))
8662 // C++ [temp.class.spec]p9:
8663 // Within the argument list of a class template partial
8664 // specialization, the following restrictions apply:
8665 // -- A partially specialized non-type argument expression
8666 // shall not involve a template parameter of the partial
8667 // specialization except when the argument expression is a
8668 // simple identifier.
8669 // -- The type of a template parameter corresponding to a
8670 // specialized non-type argument shall not be dependent on a
8671 // parameter of the specialization.
8672 // DR1315 removes the first bullet, leaving an incoherent set of rules.
8673 // We implement a compromise between the original rules and DR1315:
8674 // -- A specialized non-type template argument shall not be
8675 // type-dependent and the corresponding template parameter
8676 // shall have a non-dependent type.
8677 SourceRange ParamUseRange
=
8678 findTemplateParameterInType(Param
->getDepth(), ArgExpr
);
8679 if (ParamUseRange
.isValid()) {
8680 if (IsDefaultArgument
) {
8681 S
.Diag(TemplateNameLoc
,
8682 diag::err_dependent_non_type_arg_in_partial_spec
);
8683 S
.Diag(ParamUseRange
.getBegin(),
8684 diag::note_dependent_non_type_default_arg_in_partial_spec
)
8687 S
.Diag(ParamUseRange
.getBegin(),
8688 diag::err_dependent_non_type_arg_in_partial_spec
)
8694 ParamUseRange
= findTemplateParameter(
8695 Param
->getDepth(), Param
->getTypeSourceInfo()->getTypeLoc());
8696 if (ParamUseRange
.isValid()) {
8697 S
.Diag(IsDefaultArgument
? TemplateNameLoc
: ArgExpr
->getBeginLoc(),
8698 diag::err_dependent_typed_non_type_arg_in_partial_spec
)
8699 << Param
->getType();
8700 S
.NoteTemplateParameterLocation(*Param
);
8708 /// Check the non-type template arguments of a class template
8709 /// partial specialization according to C++ [temp.class.spec]p9.
8711 /// \param TemplateNameLoc the location of the template name.
8712 /// \param PrimaryTemplate the template parameters of the primary class
8714 /// \param NumExplicit the number of explicitly-specified template arguments.
8715 /// \param TemplateArgs the template arguments of the class template
8716 /// partial specialization.
8718 /// \returns \c true if there was an error, \c false otherwise.
8719 bool Sema::CheckTemplatePartialSpecializationArgs(
8720 SourceLocation TemplateNameLoc
, TemplateDecl
*PrimaryTemplate
,
8721 unsigned NumExplicit
, ArrayRef
<TemplateArgument
> TemplateArgs
) {
8722 // We have to be conservative when checking a template in a dependent
8724 if (PrimaryTemplate
->getDeclContext()->isDependentContext())
8727 TemplateParameterList
*TemplateParams
=
8728 PrimaryTemplate
->getTemplateParameters();
8729 for (unsigned I
= 0, N
= TemplateParams
->size(); I
!= N
; ++I
) {
8730 NonTypeTemplateParmDecl
*Param
8731 = dyn_cast
<NonTypeTemplateParmDecl
>(TemplateParams
->getParam(I
));
8735 if (CheckNonTypeTemplatePartialSpecializationArgs(*this, TemplateNameLoc
,
8736 Param
, &TemplateArgs
[I
],
8737 1, I
>= NumExplicit
))
8744 DeclResult
Sema::ActOnClassTemplateSpecialization(
8745 Scope
*S
, unsigned TagSpec
, TagUseKind TUK
, SourceLocation KWLoc
,
8746 SourceLocation ModulePrivateLoc
, CXXScopeSpec
&SS
,
8747 TemplateIdAnnotation
&TemplateId
, const ParsedAttributesView
&Attr
,
8748 MultiTemplateParamsArg TemplateParameterLists
, SkipBodyInfo
*SkipBody
) {
8749 assert(TUK
!= TUK_Reference
&& "References are not specializations");
8751 // NOTE: KWLoc is the location of the tag keyword. This will instead
8752 // store the location of the outermost template keyword in the declaration.
8753 SourceLocation TemplateKWLoc
= TemplateParameterLists
.size() > 0
8754 ? TemplateParameterLists
[0]->getTemplateLoc() : KWLoc
;
8755 SourceLocation TemplateNameLoc
= TemplateId
.TemplateNameLoc
;
8756 SourceLocation LAngleLoc
= TemplateId
.LAngleLoc
;
8757 SourceLocation RAngleLoc
= TemplateId
.RAngleLoc
;
8759 // Find the class template we're specializing
8760 TemplateName Name
= TemplateId
.Template
.get();
8761 ClassTemplateDecl
*ClassTemplate
8762 = dyn_cast_or_null
<ClassTemplateDecl
>(Name
.getAsTemplateDecl());
8764 if (!ClassTemplate
) {
8765 Diag(TemplateNameLoc
, diag::err_not_class_template_specialization
)
8766 << (Name
.getAsTemplateDecl() &&
8767 isa
<TemplateTemplateParmDecl
>(Name
.getAsTemplateDecl()));
8771 bool isMemberSpecialization
= false;
8772 bool isPartialSpecialization
= false;
8774 // Check the validity of the template headers that introduce this
8776 // FIXME: We probably shouldn't complain about these headers for
8777 // friend declarations.
8778 bool Invalid
= false;
8779 TemplateParameterList
*TemplateParams
=
8780 MatchTemplateParametersToScopeSpecifier(
8781 KWLoc
, TemplateNameLoc
, SS
, &TemplateId
,
8782 TemplateParameterLists
, TUK
== TUK_Friend
, isMemberSpecialization
,
8787 // Check that we can declare a template specialization here.
8788 if (TemplateParams
&& CheckTemplateDeclScope(S
, TemplateParams
))
8791 if (TemplateParams
&& TemplateParams
->size() > 0) {
8792 isPartialSpecialization
= true;
8794 if (TUK
== TUK_Friend
) {
8795 Diag(KWLoc
, diag::err_partial_specialization_friend
)
8796 << SourceRange(LAngleLoc
, RAngleLoc
);
8800 // C++ [temp.class.spec]p10:
8801 // The template parameter list of a specialization shall not
8802 // contain default template argument values.
8803 for (unsigned I
= 0, N
= TemplateParams
->size(); I
!= N
; ++I
) {
8804 Decl
*Param
= TemplateParams
->getParam(I
);
8805 if (TemplateTypeParmDecl
*TTP
= dyn_cast
<TemplateTypeParmDecl
>(Param
)) {
8806 if (TTP
->hasDefaultArgument()) {
8807 Diag(TTP
->getDefaultArgumentLoc(),
8808 diag::err_default_arg_in_partial_spec
);
8809 TTP
->removeDefaultArgument();
8811 } else if (NonTypeTemplateParmDecl
*NTTP
8812 = dyn_cast
<NonTypeTemplateParmDecl
>(Param
)) {
8813 if (Expr
*DefArg
= NTTP
->getDefaultArgument()) {
8814 Diag(NTTP
->getDefaultArgumentLoc(),
8815 diag::err_default_arg_in_partial_spec
)
8816 << DefArg
->getSourceRange();
8817 NTTP
->removeDefaultArgument();
8820 TemplateTemplateParmDecl
*TTP
= cast
<TemplateTemplateParmDecl
>(Param
);
8821 if (TTP
->hasDefaultArgument()) {
8822 Diag(TTP
->getDefaultArgument().getLocation(),
8823 diag::err_default_arg_in_partial_spec
)
8824 << TTP
->getDefaultArgument().getSourceRange();
8825 TTP
->removeDefaultArgument();
8829 } else if (TemplateParams
) {
8830 if (TUK
== TUK_Friend
)
8831 Diag(KWLoc
, diag::err_template_spec_friend
)
8832 << FixItHint::CreateRemoval(
8833 SourceRange(TemplateParams
->getTemplateLoc(),
8834 TemplateParams
->getRAngleLoc()))
8835 << SourceRange(LAngleLoc
, RAngleLoc
);
8837 assert(TUK
== TUK_Friend
&& "should have a 'template<>' for this decl");
8840 // Check that the specialization uses the same tag kind as the
8841 // original template.
8842 TagTypeKind Kind
= TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec
);
8843 assert(Kind
!= TagTypeKind::Enum
&&
8844 "Invalid enum tag in class template spec!");
8845 if (!isAcceptableTagRedeclaration(ClassTemplate
->getTemplatedDecl(),
8846 Kind
, TUK
== TUK_Definition
, KWLoc
,
8847 ClassTemplate
->getIdentifier())) {
8848 Diag(KWLoc
, diag::err_use_with_wrong_tag
)
8850 << FixItHint::CreateReplacement(KWLoc
,
8851 ClassTemplate
->getTemplatedDecl()->getKindName());
8852 Diag(ClassTemplate
->getTemplatedDecl()->getLocation(),
8853 diag::note_previous_use
);
8854 Kind
= ClassTemplate
->getTemplatedDecl()->getTagKind();
8857 // Translate the parser's template argument list in our AST format.
8858 TemplateArgumentListInfo TemplateArgs
=
8859 makeTemplateArgumentListInfo(*this, TemplateId
);
8861 // Check for unexpanded parameter packs in any of the template arguments.
8862 for (unsigned I
= 0, N
= TemplateArgs
.size(); I
!= N
; ++I
)
8863 if (DiagnoseUnexpandedParameterPack(TemplateArgs
[I
],
8864 isPartialSpecialization
8865 ? UPPC_PartialSpecialization
8866 : UPPC_ExplicitSpecialization
))
8869 // Check that the template argument list is well-formed for this
8871 SmallVector
<TemplateArgument
, 4> SugaredConverted
, CanonicalConverted
;
8872 if (CheckTemplateArgumentList(ClassTemplate
, TemplateNameLoc
, TemplateArgs
,
8873 false, SugaredConverted
, CanonicalConverted
,
8874 /*UpdateArgsWithConversions=*/true))
8877 // Find the class template (partial) specialization declaration that
8878 // corresponds to these arguments.
8879 if (isPartialSpecialization
) {
8880 if (CheckTemplatePartialSpecializationArgs(TemplateNameLoc
, ClassTemplate
,
8881 TemplateArgs
.size(),
8882 CanonicalConverted
))
8885 // FIXME: Move this to CheckTemplatePartialSpecializationArgs so we
8886 // also do it during instantiation.
8887 if (!Name
.isDependent() &&
8888 !TemplateSpecializationType::anyDependentTemplateArguments(
8889 TemplateArgs
, CanonicalConverted
)) {
8890 Diag(TemplateNameLoc
, diag::err_partial_spec_fully_specialized
)
8891 << ClassTemplate
->getDeclName();
8892 isPartialSpecialization
= false;
8896 void *InsertPos
= nullptr;
8897 ClassTemplateSpecializationDecl
*PrevDecl
= nullptr;
8899 if (isPartialSpecialization
)
8900 PrevDecl
= ClassTemplate
->findPartialSpecialization(
8901 CanonicalConverted
, TemplateParams
, InsertPos
);
8903 PrevDecl
= ClassTemplate
->findSpecialization(CanonicalConverted
, InsertPos
);
8905 ClassTemplateSpecializationDecl
*Specialization
= nullptr;
8907 // Check whether we can declare a class template specialization in
8908 // the current scope.
8909 if (TUK
!= TUK_Friend
&&
8910 CheckTemplateSpecializationScope(*this, ClassTemplate
, PrevDecl
,
8912 isPartialSpecialization
))
8915 // The canonical type
8917 if (isPartialSpecialization
) {
8918 // Build the canonical type that describes the converted template
8919 // arguments of the class template partial specialization.
8920 TemplateName CanonTemplate
= Context
.getCanonicalTemplateName(Name
);
8921 CanonType
= Context
.getTemplateSpecializationType(CanonTemplate
,
8922 CanonicalConverted
);
8924 if (Context
.hasSameType(CanonType
,
8925 ClassTemplate
->getInjectedClassNameSpecialization()) &&
8926 (!Context
.getLangOpts().CPlusPlus20
||
8927 !TemplateParams
->hasAssociatedConstraints())) {
8928 // C++ [temp.class.spec]p9b3:
8930 // -- The argument list of the specialization shall not be identical
8931 // to the implicit argument list of the primary template.
8933 // This rule has since been removed, because it's redundant given DR1495,
8934 // but we keep it because it produces better diagnostics and recovery.
8935 Diag(TemplateNameLoc
, diag::err_partial_spec_args_match_primary_template
)
8936 << /*class template*/0 << (TUK
== TUK_Definition
)
8937 << FixItHint::CreateRemoval(SourceRange(LAngleLoc
, RAngleLoc
));
8938 return CheckClassTemplate(S
, TagSpec
, TUK
, KWLoc
, SS
,
8939 ClassTemplate
->getIdentifier(),
8943 AS_none
, /*ModulePrivateLoc=*/SourceLocation(),
8944 /*FriendLoc*/SourceLocation(),
8945 TemplateParameterLists
.size() - 1,
8946 TemplateParameterLists
.data());
8949 // Create a new class template partial specialization declaration node.
8950 ClassTemplatePartialSpecializationDecl
*PrevPartial
8951 = cast_or_null
<ClassTemplatePartialSpecializationDecl
>(PrevDecl
);
8952 ClassTemplatePartialSpecializationDecl
*Partial
=
8953 ClassTemplatePartialSpecializationDecl::Create(
8954 Context
, Kind
, ClassTemplate
->getDeclContext(), KWLoc
,
8955 TemplateNameLoc
, TemplateParams
, ClassTemplate
, CanonicalConverted
,
8956 TemplateArgs
, CanonType
, PrevPartial
);
8957 SetNestedNameSpecifier(*this, Partial
, SS
);
8958 if (TemplateParameterLists
.size() > 1 && SS
.isSet()) {
8959 Partial
->setTemplateParameterListsInfo(
8960 Context
, TemplateParameterLists
.drop_back(1));
8964 ClassTemplate
->AddPartialSpecialization(Partial
, InsertPos
);
8965 Specialization
= Partial
;
8967 // If we are providing an explicit specialization of a member class
8968 // template specialization, make a note of that.
8969 if (PrevPartial
&& PrevPartial
->getInstantiatedFromMember())
8970 PrevPartial
->setMemberSpecialization();
8972 CheckTemplatePartialSpecialization(Partial
);
8974 // Create a new class template specialization declaration node for
8975 // this explicit specialization or friend declaration.
8976 Specialization
= ClassTemplateSpecializationDecl::Create(
8977 Context
, Kind
, ClassTemplate
->getDeclContext(), KWLoc
, TemplateNameLoc
,
8978 ClassTemplate
, CanonicalConverted
, PrevDecl
);
8979 SetNestedNameSpecifier(*this, Specialization
, SS
);
8980 if (TemplateParameterLists
.size() > 0) {
8981 Specialization
->setTemplateParameterListsInfo(Context
,
8982 TemplateParameterLists
);
8986 ClassTemplate
->AddSpecialization(Specialization
, InsertPos
);
8988 if (CurContext
->isDependentContext()) {
8989 TemplateName CanonTemplate
= Context
.getCanonicalTemplateName(Name
);
8990 CanonType
= Context
.getTemplateSpecializationType(CanonTemplate
,
8991 CanonicalConverted
);
8993 CanonType
= Context
.getTypeDeclType(Specialization
);
8997 // C++ [temp.expl.spec]p6:
8998 // If a template, a member template or the member of a class template is
8999 // explicitly specialized then that specialization shall be declared
9000 // before the first use of that specialization that would cause an implicit
9001 // instantiation to take place, in every translation unit in which such a
9002 // use occurs; no diagnostic is required.
9003 if (PrevDecl
&& PrevDecl
->getPointOfInstantiation().isValid()) {
9005 for (Decl
*Prev
= PrevDecl
; Prev
; Prev
= Prev
->getPreviousDecl()) {
9006 // Is there any previous explicit specialization declaration?
9007 if (getTemplateSpecializationKind(Prev
) == TSK_ExplicitSpecialization
) {
9014 SourceRange
Range(TemplateNameLoc
, RAngleLoc
);
9015 Diag(TemplateNameLoc
, diag::err_specialization_after_instantiation
)
9016 << Context
.getTypeDeclType(Specialization
) << Range
;
9018 Diag(PrevDecl
->getPointOfInstantiation(),
9019 diag::note_instantiation_required_here
)
9020 << (PrevDecl
->getTemplateSpecializationKind()
9021 != TSK_ImplicitInstantiation
);
9026 // If this is not a friend, note that this is an explicit specialization.
9027 if (TUK
!= TUK_Friend
)
9028 Specialization
->setSpecializationKind(TSK_ExplicitSpecialization
);
9030 // Check that this isn't a redefinition of this specialization.
9031 if (TUK
== TUK_Definition
) {
9032 RecordDecl
*Def
= Specialization
->getDefinition();
9033 NamedDecl
*Hidden
= nullptr;
9034 if (Def
&& SkipBody
&& !hasVisibleDefinition(Def
, &Hidden
)) {
9035 SkipBody
->ShouldSkip
= true;
9036 SkipBody
->Previous
= Def
;
9037 makeMergedDefinitionVisible(Hidden
);
9039 SourceRange
Range(TemplateNameLoc
, RAngleLoc
);
9040 Diag(TemplateNameLoc
, diag::err_redefinition
) << Specialization
<< Range
;
9041 Diag(Def
->getLocation(), diag::note_previous_definition
);
9042 Specialization
->setInvalidDecl();
9047 ProcessDeclAttributeList(S
, Specialization
, Attr
);
9049 // Add alignment attributes if necessary; these attributes are checked when
9050 // the ASTContext lays out the structure.
9051 if (TUK
== TUK_Definition
&& (!SkipBody
|| !SkipBody
->ShouldSkip
)) {
9052 AddAlignmentAttributesForRecord(Specialization
);
9053 AddMsStructLayoutForRecord(Specialization
);
9056 if (ModulePrivateLoc
.isValid())
9057 Diag(Specialization
->getLocation(), diag::err_module_private_specialization
)
9058 << (isPartialSpecialization
? 1 : 0)
9059 << FixItHint::CreateRemoval(ModulePrivateLoc
);
9061 // Build the fully-sugared type for this class template
9062 // specialization as the user wrote in the specialization
9063 // itself. This means that we'll pretty-print the type retrieved
9064 // from the specialization's declaration the way that the user
9065 // actually wrote the specialization, rather than formatting the
9066 // name based on the "canonical" representation used to store the
9067 // template arguments in the specialization.
9068 TypeSourceInfo
*WrittenTy
9069 = Context
.getTemplateSpecializationTypeInfo(Name
, TemplateNameLoc
,
9070 TemplateArgs
, CanonType
);
9071 if (TUK
!= TUK_Friend
) {
9072 Specialization
->setTypeAsWritten(WrittenTy
);
9073 Specialization
->setTemplateKeywordLoc(TemplateKWLoc
);
9076 // C++ [temp.expl.spec]p9:
9077 // A template explicit specialization is in the scope of the
9078 // namespace in which the template was defined.
9080 // We actually implement this paragraph where we set the semantic
9081 // context (in the creation of the ClassTemplateSpecializationDecl),
9082 // but we also maintain the lexical context where the actual
9083 // definition occurs.
9084 Specialization
->setLexicalDeclContext(CurContext
);
9086 // We may be starting the definition of this specialization.
9087 if (TUK
== TUK_Definition
&& (!SkipBody
|| !SkipBody
->ShouldSkip
))
9088 Specialization
->startDefinition();
9090 if (TUK
== TUK_Friend
) {
9091 FriendDecl
*Friend
= FriendDecl::Create(Context
, CurContext
,
9095 Friend
->setAccess(AS_public
);
9096 CurContext
->addDecl(Friend
);
9098 // Add the specialization into its lexical context, so that it can
9099 // be seen when iterating through the list of declarations in that
9100 // context. However, specializations are not found by name lookup.
9101 CurContext
->addDecl(Specialization
);
9104 if (SkipBody
&& SkipBody
->ShouldSkip
)
9105 return SkipBody
->Previous
;
9107 return Specialization
;
9110 Decl
*Sema::ActOnTemplateDeclarator(Scope
*S
,
9111 MultiTemplateParamsArg TemplateParameterLists
,
9113 Decl
*NewDecl
= HandleDeclarator(S
, D
, TemplateParameterLists
);
9114 ActOnDocumentableDecl(NewDecl
);
9118 Decl
*Sema::ActOnConceptDefinition(Scope
*S
,
9119 MultiTemplateParamsArg TemplateParameterLists
,
9120 IdentifierInfo
*Name
, SourceLocation NameLoc
,
9121 Expr
*ConstraintExpr
) {
9122 DeclContext
*DC
= CurContext
;
9124 if (!DC
->getRedeclContext()->isFileContext()) {
9126 diag::err_concept_decls_may_only_appear_in_global_namespace_scope
);
9130 if (TemplateParameterLists
.size() > 1) {
9131 Diag(NameLoc
, diag::err_concept_extra_headers
);
9135 TemplateParameterList
*Params
= TemplateParameterLists
.front();
9137 if (Params
->size() == 0) {
9138 Diag(NameLoc
, diag::err_concept_no_parameters
);
9142 // Ensure that the parameter pack, if present, is the last parameter in the
9144 for (TemplateParameterList::const_iterator ParamIt
= Params
->begin(),
9145 ParamEnd
= Params
->end();
9146 ParamIt
!= ParamEnd
; ++ParamIt
) {
9147 Decl
const *Param
= *ParamIt
;
9148 if (Param
->isParameterPack()) {
9149 if (++ParamIt
== ParamEnd
)
9151 Diag(Param
->getLocation(),
9152 diag::err_template_param_pack_must_be_last_template_parameter
);
9157 if (DiagnoseUnexpandedParameterPack(ConstraintExpr
))
9160 ConceptDecl
*NewDecl
=
9161 ConceptDecl::Create(Context
, DC
, NameLoc
, Name
, Params
, ConstraintExpr
);
9163 if (NewDecl
->hasAssociatedConstraints()) {
9164 // C++2a [temp.concept]p4:
9165 // A concept shall not have associated constraints.
9166 Diag(NameLoc
, diag::err_concept_no_associated_constraints
);
9167 NewDecl
->setInvalidDecl();
9170 // Check for conflicting previous declaration.
9171 DeclarationNameInfo
NameInfo(NewDecl
->getDeclName(), NameLoc
);
9172 LookupResult
Previous(*this, NameInfo
, LookupOrdinaryName
,
9173 forRedeclarationInCurContext());
9174 LookupName(Previous
, S
);
9175 FilterLookupForScope(Previous
, DC
, S
, /*ConsiderLinkage=*/false,
9176 /*AllowInlineNamespace*/false);
9177 bool AddToScope
= true;
9178 CheckConceptRedefinition(NewDecl
, Previous
, AddToScope
);
9180 ActOnDocumentableDecl(NewDecl
);
9182 PushOnScopeChains(NewDecl
, S
);
9186 void Sema::CheckConceptRedefinition(ConceptDecl
*NewDecl
,
9187 LookupResult
&Previous
, bool &AddToScope
) {
9190 if (Previous
.empty())
9193 auto *OldConcept
= dyn_cast
<ConceptDecl
>(Previous
.getRepresentativeDecl()->getUnderlyingDecl());
9195 auto *Old
= Previous
.getRepresentativeDecl();
9196 Diag(NewDecl
->getLocation(), diag::err_redefinition_different_kind
)
9197 << NewDecl
->getDeclName();
9198 notePreviousDefinition(Old
, NewDecl
->getLocation());
9202 // Check if we can merge with a concept declaration.
9203 bool IsSame
= Context
.isSameEntity(NewDecl
, OldConcept
);
9205 Diag(NewDecl
->getLocation(), diag::err_redefinition_different_concept
)
9206 << NewDecl
->getDeclName();
9207 notePreviousDefinition(OldConcept
, NewDecl
->getLocation());
9211 if (hasReachableDefinition(OldConcept
) &&
9212 IsRedefinitionInModule(NewDecl
, OldConcept
)) {
9213 Diag(NewDecl
->getLocation(), diag::err_redefinition
)
9214 << NewDecl
->getDeclName();
9215 notePreviousDefinition(OldConcept
, NewDecl
->getLocation());
9219 if (!Previous
.isSingleResult()) {
9220 // FIXME: we should produce an error in case of ambig and failed lookups.
9221 // Other decls (e.g. namespaces) also have this shortcoming.
9224 // We unwrap canonical decl late to check for module visibility.
9225 Context
.setPrimaryMergedDecl(NewDecl
, OldConcept
->getCanonicalDecl());
9228 /// \brief Strips various properties off an implicit instantiation
9229 /// that has just been explicitly specialized.
9230 static void StripImplicitInstantiation(NamedDecl
*D
, bool MinGW
) {
9231 if (MinGW
|| (isa
<FunctionDecl
>(D
) &&
9232 cast
<FunctionDecl
>(D
)->isFunctionTemplateSpecialization())) {
9233 D
->dropAttr
<DLLImportAttr
>();
9234 D
->dropAttr
<DLLExportAttr
>();
9237 if (FunctionDecl
*FD
= dyn_cast
<FunctionDecl
>(D
))
9238 FD
->setInlineSpecified(false);
9241 /// Compute the diagnostic location for an explicit instantiation
9242 // declaration or definition.
9243 static SourceLocation
DiagLocForExplicitInstantiation(
9244 NamedDecl
* D
, SourceLocation PointOfInstantiation
) {
9245 // Explicit instantiations following a specialization have no effect and
9246 // hence no PointOfInstantiation. In that case, walk decl backwards
9247 // until a valid name loc is found.
9248 SourceLocation PrevDiagLoc
= PointOfInstantiation
;
9249 for (Decl
*Prev
= D
; Prev
&& !PrevDiagLoc
.isValid();
9250 Prev
= Prev
->getPreviousDecl()) {
9251 PrevDiagLoc
= Prev
->getLocation();
9253 assert(PrevDiagLoc
.isValid() &&
9254 "Explicit instantiation without point of instantiation?");
9258 /// Diagnose cases where we have an explicit template specialization
9259 /// before/after an explicit template instantiation, producing diagnostics
9260 /// for those cases where they are required and determining whether the
9261 /// new specialization/instantiation will have any effect.
9263 /// \param NewLoc the location of the new explicit specialization or
9266 /// \param NewTSK the kind of the new explicit specialization or instantiation.
9268 /// \param PrevDecl the previous declaration of the entity.
9270 /// \param PrevTSK the kind of the old explicit specialization or instantiatin.
9272 /// \param PrevPointOfInstantiation if valid, indicates where the previous
9273 /// declaration was instantiated (either implicitly or explicitly).
9275 /// \param HasNoEffect will be set to true to indicate that the new
9276 /// specialization or instantiation has no effect and should be ignored.
9278 /// \returns true if there was an error that should prevent the introduction of
9279 /// the new declaration into the AST, false otherwise.
9281 Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc
,
9282 TemplateSpecializationKind NewTSK
,
9283 NamedDecl
*PrevDecl
,
9284 TemplateSpecializationKind PrevTSK
,
9285 SourceLocation PrevPointOfInstantiation
,
9286 bool &HasNoEffect
) {
9287 HasNoEffect
= false;
9290 case TSK_Undeclared
:
9291 case TSK_ImplicitInstantiation
:
9293 (PrevTSK
== TSK_Undeclared
|| PrevTSK
== TSK_ImplicitInstantiation
) &&
9294 "previous declaration must be implicit!");
9297 case TSK_ExplicitSpecialization
:
9299 case TSK_Undeclared
:
9300 case TSK_ExplicitSpecialization
:
9301 // Okay, we're just specializing something that is either already
9302 // explicitly specialized or has merely been mentioned without any
9306 case TSK_ImplicitInstantiation
:
9307 if (PrevPointOfInstantiation
.isInvalid()) {
9308 // The declaration itself has not actually been instantiated, so it is
9309 // still okay to specialize it.
9310 StripImplicitInstantiation(
9312 Context
.getTargetInfo().getTriple().isWindowsGNUEnvironment());
9318 case TSK_ExplicitInstantiationDeclaration
:
9319 case TSK_ExplicitInstantiationDefinition
:
9320 assert((PrevTSK
== TSK_ImplicitInstantiation
||
9321 PrevPointOfInstantiation
.isValid()) &&
9322 "Explicit instantiation without point of instantiation?");
9324 // C++ [temp.expl.spec]p6:
9325 // If a template, a member template or the member of a class template
9326 // is explicitly specialized then that specialization shall be declared
9327 // before the first use of that specialization that would cause an
9328 // implicit instantiation to take place, in every translation unit in
9329 // which such a use occurs; no diagnostic is required.
9330 for (Decl
*Prev
= PrevDecl
; Prev
; Prev
= Prev
->getPreviousDecl()) {
9331 // Is there any previous explicit specialization declaration?
9332 if (getTemplateSpecializationKind(Prev
) == TSK_ExplicitSpecialization
)
9336 Diag(NewLoc
, diag::err_specialization_after_instantiation
)
9338 Diag(PrevPointOfInstantiation
, diag::note_instantiation_required_here
)
9339 << (PrevTSK
!= TSK_ImplicitInstantiation
);
9343 llvm_unreachable("The switch over PrevTSK must be exhaustive.");
9345 case TSK_ExplicitInstantiationDeclaration
:
9347 case TSK_ExplicitInstantiationDeclaration
:
9348 // This explicit instantiation declaration is redundant (that's okay).
9352 case TSK_Undeclared
:
9353 case TSK_ImplicitInstantiation
:
9354 // We're explicitly instantiating something that may have already been
9355 // implicitly instantiated; that's fine.
9358 case TSK_ExplicitSpecialization
:
9359 // C++0x [temp.explicit]p4:
9360 // For a given set of template parameters, if an explicit instantiation
9361 // of a template appears after a declaration of an explicit
9362 // specialization for that template, the explicit instantiation has no
9367 case TSK_ExplicitInstantiationDefinition
:
9368 // C++0x [temp.explicit]p10:
9369 // If an entity is the subject of both an explicit instantiation
9370 // declaration and an explicit instantiation definition in the same
9371 // translation unit, the definition shall follow the declaration.
9373 diag::err_explicit_instantiation_declaration_after_definition
);
9375 // Explicit instantiations following a specialization have no effect and
9376 // hence no PrevPointOfInstantiation. In that case, walk decl backwards
9377 // until a valid name loc is found.
9378 Diag(DiagLocForExplicitInstantiation(PrevDecl
, PrevPointOfInstantiation
),
9379 diag::note_explicit_instantiation_definition_here
);
9383 llvm_unreachable("Unexpected TemplateSpecializationKind!");
9385 case TSK_ExplicitInstantiationDefinition
:
9387 case TSK_Undeclared
:
9388 case TSK_ImplicitInstantiation
:
9389 // We're explicitly instantiating something that may have already been
9390 // implicitly instantiated; that's fine.
9393 case TSK_ExplicitSpecialization
:
9394 // C++ DR 259, C++0x [temp.explicit]p4:
9395 // For a given set of template parameters, if an explicit
9396 // instantiation of a template appears after a declaration of
9397 // an explicit specialization for that template, the explicit
9398 // instantiation has no effect.
9399 Diag(NewLoc
, diag::warn_explicit_instantiation_after_specialization
)
9401 Diag(PrevDecl
->getLocation(),
9402 diag::note_previous_template_specialization
);
9406 case TSK_ExplicitInstantiationDeclaration
:
9407 // We're explicitly instantiating a definition for something for which we
9408 // were previously asked to suppress instantiations. That's fine.
9410 // C++0x [temp.explicit]p4:
9411 // For a given set of template parameters, if an explicit instantiation
9412 // of a template appears after a declaration of an explicit
9413 // specialization for that template, the explicit instantiation has no
9415 for (Decl
*Prev
= PrevDecl
; Prev
; Prev
= Prev
->getPreviousDecl()) {
9416 // Is there any previous explicit specialization declaration?
9417 if (getTemplateSpecializationKind(Prev
) == TSK_ExplicitSpecialization
) {
9425 case TSK_ExplicitInstantiationDefinition
:
9426 // C++0x [temp.spec]p5:
9427 // For a given template and a given set of template-arguments,
9428 // - an explicit instantiation definition shall appear at most once
9431 // MSVCCompat: MSVC silently ignores duplicate explicit instantiations.
9432 Diag(NewLoc
, (getLangOpts().MSVCCompat
)
9433 ? diag::ext_explicit_instantiation_duplicate
9434 : diag::err_explicit_instantiation_duplicate
)
9436 Diag(DiagLocForExplicitInstantiation(PrevDecl
, PrevPointOfInstantiation
),
9437 diag::note_previous_explicit_instantiation
);
9443 llvm_unreachable("Missing specialization/instantiation case?");
9446 /// Perform semantic analysis for the given dependent function
9447 /// template specialization.
9449 /// The only possible way to get a dependent function template specialization
9450 /// is with a friend declaration, like so:
9453 /// template \<class T> void foo(T);
9454 /// template \<class T> class A {
9455 /// friend void foo<>(T);
9459 /// There really isn't any useful analysis we can do here, so we
9460 /// just store the information.
9461 bool Sema::CheckDependentFunctionTemplateSpecialization(
9462 FunctionDecl
*FD
, const TemplateArgumentListInfo
*ExplicitTemplateArgs
,
9463 LookupResult
&Previous
) {
9464 // Remove anything from Previous that isn't a function template in
9465 // the correct context.
9466 DeclContext
*FDLookupContext
= FD
->getDeclContext()->getRedeclContext();
9467 LookupResult::Filter F
= Previous
.makeFilter();
9468 enum DiscardReason
{ NotAFunctionTemplate
, NotAMemberOfEnclosing
};
9469 SmallVector
<std::pair
<DiscardReason
, Decl
*>, 8> DiscardedCandidates
;
9470 while (F
.hasNext()) {
9471 NamedDecl
*D
= F
.next()->getUnderlyingDecl();
9472 if (!isa
<FunctionTemplateDecl
>(D
)) {
9474 DiscardedCandidates
.push_back(std::make_pair(NotAFunctionTemplate
, D
));
9478 if (!FDLookupContext
->InEnclosingNamespaceSetOf(
9479 D
->getDeclContext()->getRedeclContext())) {
9481 DiscardedCandidates
.push_back(std::make_pair(NotAMemberOfEnclosing
, D
));
9487 bool IsFriend
= FD
->getFriendObjectKind() != Decl::FOK_None
;
9488 if (Previous
.empty()) {
9489 Diag(FD
->getLocation(), diag::err_dependent_function_template_spec_no_match
)
9491 for (auto &P
: DiscardedCandidates
)
9492 Diag(P
.second
->getLocation(),
9493 diag::note_dependent_function_template_spec_discard_reason
)
9494 << P
.first
<< IsFriend
;
9498 FD
->setDependentTemplateSpecialization(Context
, Previous
.asUnresolvedSet(),
9499 ExplicitTemplateArgs
);
9503 /// Perform semantic analysis for the given function template
9506 /// This routine performs all of the semantic analysis required for an
9507 /// explicit function template specialization. On successful completion,
9508 /// the function declaration \p FD will become a function template
9511 /// \param FD the function declaration, which will be updated to become a
9512 /// function template specialization.
9514 /// \param ExplicitTemplateArgs the explicitly-provided template arguments,
9515 /// if any. Note that this may be valid info even when 0 arguments are
9516 /// explicitly provided as in, e.g., \c void sort<>(char*, char*);
9517 /// as it anyway contains info on the angle brackets locations.
9519 /// \param Previous the set of declarations that may be specialized by
9520 /// this function specialization.
9522 /// \param QualifiedFriend whether this is a lookup for a qualified friend
9523 /// declaration with no explicit template argument list that might be
9524 /// befriending a function template specialization.
9525 bool Sema::CheckFunctionTemplateSpecialization(
9526 FunctionDecl
*FD
, TemplateArgumentListInfo
*ExplicitTemplateArgs
,
9527 LookupResult
&Previous
, bool QualifiedFriend
) {
9528 // The set of function template specializations that could match this
9529 // explicit function template specialization.
9530 UnresolvedSet
<8> Candidates
;
9531 TemplateSpecCandidateSet
FailedCandidates(FD
->getLocation(),
9532 /*ForTakingAddress=*/false);
9534 llvm::SmallDenseMap
<FunctionDecl
*, TemplateArgumentListInfo
, 8>
9535 ConvertedTemplateArgs
;
9537 DeclContext
*FDLookupContext
= FD
->getDeclContext()->getRedeclContext();
9538 for (LookupResult::iterator I
= Previous
.begin(), E
= Previous
.end();
9540 NamedDecl
*Ovl
= (*I
)->getUnderlyingDecl();
9541 if (FunctionTemplateDecl
*FunTmpl
= dyn_cast
<FunctionTemplateDecl
>(Ovl
)) {
9542 // Only consider templates found within the same semantic lookup scope as
9544 if (!FDLookupContext
->InEnclosingNamespaceSetOf(
9545 Ovl
->getDeclContext()->getRedeclContext()))
9548 // When matching a constexpr member function template specialization
9549 // against the primary template, we don't yet know whether the
9550 // specialization has an implicit 'const' (because we don't know whether
9551 // it will be a static member function until we know which template it
9552 // specializes), so adjust it now assuming it specializes this template.
9553 QualType FT
= FD
->getType();
9554 if (FD
->isConstexpr()) {
9555 CXXMethodDecl
*OldMD
=
9556 dyn_cast
<CXXMethodDecl
>(FunTmpl
->getTemplatedDecl());
9557 if (OldMD
&& OldMD
->isConst()) {
9558 const FunctionProtoType
*FPT
= FT
->castAs
<FunctionProtoType
>();
9559 FunctionProtoType::ExtProtoInfo EPI
= FPT
->getExtProtoInfo();
9560 EPI
.TypeQuals
.addConst();
9561 FT
= Context
.getFunctionType(FPT
->getReturnType(),
9562 FPT
->getParamTypes(), EPI
);
9566 TemplateArgumentListInfo Args
;
9567 if (ExplicitTemplateArgs
)
9568 Args
= *ExplicitTemplateArgs
;
9570 // C++ [temp.expl.spec]p11:
9571 // A trailing template-argument can be left unspecified in the
9572 // template-id naming an explicit function template specialization
9573 // provided it can be deduced from the function argument type.
9574 // Perform template argument deduction to determine whether we may be
9575 // specializing this template.
9576 // FIXME: It is somewhat wasteful to build
9577 TemplateDeductionInfo
Info(FailedCandidates
.getLocation());
9578 FunctionDecl
*Specialization
= nullptr;
9579 if (TemplateDeductionResult TDK
= DeduceTemplateArguments(
9580 cast
<FunctionTemplateDecl
>(FunTmpl
->getFirstDecl()),
9581 ExplicitTemplateArgs
? &Args
: nullptr, FT
, Specialization
,
9583 // Template argument deduction failed; record why it failed, so
9584 // that we can provide nifty diagnostics.
9585 FailedCandidates
.addCandidate().set(
9586 I
.getPair(), FunTmpl
->getTemplatedDecl(),
9587 MakeDeductionFailureInfo(Context
, TDK
, Info
));
9592 // Target attributes are part of the cuda function signature, so
9593 // the deduced template's cuda target must match that of the
9594 // specialization. Given that C++ template deduction does not
9595 // take target attributes into account, we reject candidates
9596 // here that have a different target.
9597 if (LangOpts
.CUDA
&&
9598 IdentifyCUDATarget(Specialization
,
9599 /* IgnoreImplicitHDAttr = */ true) !=
9600 IdentifyCUDATarget(FD
, /* IgnoreImplicitHDAttr = */ true)) {
9601 FailedCandidates
.addCandidate().set(
9602 I
.getPair(), FunTmpl
->getTemplatedDecl(),
9603 MakeDeductionFailureInfo(Context
, TDK_CUDATargetMismatch
, Info
));
9607 // Record this candidate.
9608 if (ExplicitTemplateArgs
)
9609 ConvertedTemplateArgs
[Specialization
] = std::move(Args
);
9610 Candidates
.addDecl(Specialization
, I
.getAccess());
9614 // For a qualified friend declaration (with no explicit marker to indicate
9615 // that a template specialization was intended), note all (template and
9616 // non-template) candidates.
9617 if (QualifiedFriend
&& Candidates
.empty()) {
9618 Diag(FD
->getLocation(), diag::err_qualified_friend_no_match
)
9619 << FD
->getDeclName() << FDLookupContext
;
9620 // FIXME: We should form a single candidate list and diagnose all
9621 // candidates at once, to get proper sorting and limiting.
9622 for (auto *OldND
: Previous
) {
9623 if (auto *OldFD
= dyn_cast
<FunctionDecl
>(OldND
->getUnderlyingDecl()))
9624 NoteOverloadCandidate(OldND
, OldFD
, CRK_None
, FD
->getType(), false);
9626 FailedCandidates
.NoteCandidates(*this, FD
->getLocation());
9630 // Find the most specialized function template.
9631 UnresolvedSetIterator Result
= getMostSpecialized(
9632 Candidates
.begin(), Candidates
.end(), FailedCandidates
, FD
->getLocation(),
9633 PDiag(diag::err_function_template_spec_no_match
) << FD
->getDeclName(),
9634 PDiag(diag::err_function_template_spec_ambiguous
)
9635 << FD
->getDeclName() << (ExplicitTemplateArgs
!= nullptr),
9636 PDiag(diag::note_function_template_spec_matched
));
9638 if (Result
== Candidates
.end())
9641 // Ignore access information; it doesn't figure into redeclaration checking.
9642 FunctionDecl
*Specialization
= cast
<FunctionDecl
>(*Result
);
9644 FunctionTemplateSpecializationInfo
*SpecInfo
9645 = Specialization
->getTemplateSpecializationInfo();
9646 assert(SpecInfo
&& "Function template specialization info missing?");
9648 // Note: do not overwrite location info if previous template
9649 // specialization kind was explicit.
9650 TemplateSpecializationKind TSK
= SpecInfo
->getTemplateSpecializationKind();
9651 if (TSK
== TSK_Undeclared
|| TSK
== TSK_ImplicitInstantiation
) {
9652 Specialization
->setLocation(FD
->getLocation());
9653 Specialization
->setLexicalDeclContext(FD
->getLexicalDeclContext());
9654 // C++11 [dcl.constexpr]p1: An explicit specialization of a constexpr
9655 // function can differ from the template declaration with respect to
9656 // the constexpr specifier.
9657 // FIXME: We need an update record for this AST mutation.
9658 // FIXME: What if there are multiple such prior declarations (for instance,
9659 // from different modules)?
9660 Specialization
->setConstexprKind(FD
->getConstexprKind());
9663 // FIXME: Check if the prior specialization has a point of instantiation.
9664 // If so, we have run afoul of .
9666 // If this is a friend declaration, then we're not really declaring
9667 // an explicit specialization.
9668 bool isFriend
= (FD
->getFriendObjectKind() != Decl::FOK_None
);
9670 // Check the scope of this explicit specialization.
9672 CheckTemplateSpecializationScope(*this,
9673 Specialization
->getPrimaryTemplate(),
9674 Specialization
, FD
->getLocation(),
9678 // C++ [temp.expl.spec]p6:
9679 // If a template, a member template or the member of a class template is
9680 // explicitly specialized then that specialization shall be declared
9681 // before the first use of that specialization that would cause an implicit
9682 // instantiation to take place, in every translation unit in which such a
9683 // use occurs; no diagnostic is required.
9684 bool HasNoEffect
= false;
9686 CheckSpecializationInstantiationRedecl(FD
->getLocation(),
9687 TSK_ExplicitSpecialization
,
9689 SpecInfo
->getTemplateSpecializationKind(),
9690 SpecInfo
->getPointOfInstantiation(),
9694 // Mark the prior declaration as an explicit specialization, so that later
9695 // clients know that this is an explicit specialization.
9697 // Since explicit specializations do not inherit '=delete' from their
9698 // primary function template - check if the 'specialization' that was
9699 // implicitly generated (during template argument deduction for partial
9700 // ordering) from the most specialized of all the function templates that
9701 // 'FD' could have been specializing, has a 'deleted' definition. If so,
9702 // first check that it was implicitly generated during template argument
9703 // deduction by making sure it wasn't referenced, and then reset the deleted
9704 // flag to not-deleted, so that we can inherit that information from 'FD'.
9705 if (Specialization
->isDeleted() && !SpecInfo
->isExplicitSpecialization() &&
9706 !Specialization
->getCanonicalDecl()->isReferenced()) {
9707 // FIXME: This assert will not hold in the presence of modules.
9709 Specialization
->getCanonicalDecl() == Specialization
&&
9710 "This must be the only existing declaration of this specialization");
9711 // FIXME: We need an update record for this AST mutation.
9712 Specialization
->setDeletedAsWritten(false);
9714 // FIXME: We need an update record for this AST mutation.
9715 SpecInfo
->setTemplateSpecializationKind(TSK_ExplicitSpecialization
);
9716 MarkUnusedFileScopedDecl(Specialization
);
9719 // Turn the given function declaration into a function template
9720 // specialization, with the template arguments from the previous
9722 // Take copies of (semantic and syntactic) template argument lists.
9723 const TemplateArgumentList
* TemplArgs
= new (Context
)
9724 TemplateArgumentList(Specialization
->getTemplateSpecializationArgs());
9725 FD
->setFunctionTemplateSpecialization(
9726 Specialization
->getPrimaryTemplate(), TemplArgs
, /*InsertPos=*/nullptr,
9727 SpecInfo
->getTemplateSpecializationKind(),
9728 ExplicitTemplateArgs
? &ConvertedTemplateArgs
[Specialization
] : nullptr);
9730 // A function template specialization inherits the target attributes
9731 // of its template. (We require the attributes explicitly in the
9732 // code to match, but a template may have implicit attributes by
9733 // virtue e.g. of being constexpr, and it passes these implicit
9734 // attributes on to its specializations.)
9736 inheritCUDATargetAttrs(FD
, *Specialization
->getPrimaryTemplate());
9738 // The "previous declaration" for this function template specialization is
9739 // the prior function template specialization.
9741 Previous
.addDecl(Specialization
);
9745 /// Perform semantic analysis for the given non-template member
9748 /// This routine performs all of the semantic analysis required for an
9749 /// explicit member function specialization. On successful completion,
9750 /// the function declaration \p FD will become a member function
9753 /// \param Member the member declaration, which will be updated to become a
9756 /// \param Previous the set of declarations, one of which may be specialized
9757 /// by this function specialization; the set will be modified to contain the
9758 /// redeclared member.
9760 Sema::CheckMemberSpecialization(NamedDecl
*Member
, LookupResult
&Previous
) {
9761 assert(!isa
<TemplateDecl
>(Member
) && "Only for non-template members");
9763 // Try to find the member we are instantiating.
9764 NamedDecl
*FoundInstantiation
= nullptr;
9765 NamedDecl
*Instantiation
= nullptr;
9766 NamedDecl
*InstantiatedFrom
= nullptr;
9767 MemberSpecializationInfo
*MSInfo
= nullptr;
9769 if (Previous
.empty()) {
9770 // Nowhere to look anyway.
9771 } else if (FunctionDecl
*Function
= dyn_cast
<FunctionDecl
>(Member
)) {
9772 for (LookupResult::iterator I
= Previous
.begin(), E
= Previous
.end();
9774 NamedDecl
*D
= (*I
)->getUnderlyingDecl();
9775 if (CXXMethodDecl
*Method
= dyn_cast
<CXXMethodDecl
>(D
)) {
9776 QualType Adjusted
= Function
->getType();
9777 if (!hasExplicitCallingConv(Adjusted
))
9778 Adjusted
= adjustCCAndNoReturn(Adjusted
, Method
->getType());
9779 // This doesn't handle deduced return types, but both function
9780 // declarations should be undeduced at this point.
9781 if (Context
.hasSameType(Adjusted
, Method
->getType())) {
9782 FoundInstantiation
= *I
;
9783 Instantiation
= Method
;
9784 InstantiatedFrom
= Method
->getInstantiatedFromMemberFunction();
9785 MSInfo
= Method
->getMemberSpecializationInfo();
9790 } else if (isa
<VarDecl
>(Member
)) {
9792 if (Previous
.isSingleResult() &&
9793 (PrevVar
= dyn_cast
<VarDecl
>(Previous
.getFoundDecl())))
9794 if (PrevVar
->isStaticDataMember()) {
9795 FoundInstantiation
= Previous
.getRepresentativeDecl();
9796 Instantiation
= PrevVar
;
9797 InstantiatedFrom
= PrevVar
->getInstantiatedFromStaticDataMember();
9798 MSInfo
= PrevVar
->getMemberSpecializationInfo();
9800 } else if (isa
<RecordDecl
>(Member
)) {
9801 CXXRecordDecl
*PrevRecord
;
9802 if (Previous
.isSingleResult() &&
9803 (PrevRecord
= dyn_cast
<CXXRecordDecl
>(Previous
.getFoundDecl()))) {
9804 FoundInstantiation
= Previous
.getRepresentativeDecl();
9805 Instantiation
= PrevRecord
;
9806 InstantiatedFrom
= PrevRecord
->getInstantiatedFromMemberClass();
9807 MSInfo
= PrevRecord
->getMemberSpecializationInfo();
9809 } else if (isa
<EnumDecl
>(Member
)) {
9811 if (Previous
.isSingleResult() &&
9812 (PrevEnum
= dyn_cast
<EnumDecl
>(Previous
.getFoundDecl()))) {
9813 FoundInstantiation
= Previous
.getRepresentativeDecl();
9814 Instantiation
= PrevEnum
;
9815 InstantiatedFrom
= PrevEnum
->getInstantiatedFromMemberEnum();
9816 MSInfo
= PrevEnum
->getMemberSpecializationInfo();
9820 if (!Instantiation
) {
9821 // There is no previous declaration that matches. Since member
9822 // specializations are always out-of-line, the caller will complain about
9823 // this mismatch later.
9827 // A member specialization in a friend declaration isn't really declaring
9828 // an explicit specialization, just identifying a specific (possibly implicit)
9829 // specialization. Don't change the template specialization kind.
9831 // FIXME: Is this really valid? Other compilers reject.
9832 if (Member
->getFriendObjectKind() != Decl::FOK_None
) {
9833 // Preserve instantiation information.
9834 if (InstantiatedFrom
&& isa
<CXXMethodDecl
>(Member
)) {
9835 cast
<CXXMethodDecl
>(Member
)->setInstantiationOfMemberFunction(
9836 cast
<CXXMethodDecl
>(InstantiatedFrom
),
9837 cast
<CXXMethodDecl
>(Instantiation
)->getTemplateSpecializationKind());
9838 } else if (InstantiatedFrom
&& isa
<CXXRecordDecl
>(Member
)) {
9839 cast
<CXXRecordDecl
>(Member
)->setInstantiationOfMemberClass(
9840 cast
<CXXRecordDecl
>(InstantiatedFrom
),
9841 cast
<CXXRecordDecl
>(Instantiation
)->getTemplateSpecializationKind());
9845 Previous
.addDecl(FoundInstantiation
);
9849 // Make sure that this is a specialization of a member.
9850 if (!InstantiatedFrom
) {
9851 Diag(Member
->getLocation(), diag::err_spec_member_not_instantiated
)
9853 Diag(Instantiation
->getLocation(), diag::note_specialized_decl
);
9857 // C++ [temp.expl.spec]p6:
9858 // If a template, a member template or the member of a class template is
9859 // explicitly specialized then that specialization shall be declared
9860 // before the first use of that specialization that would cause an implicit
9861 // instantiation to take place, in every translation unit in which such a
9862 // use occurs; no diagnostic is required.
9863 assert(MSInfo
&& "Member specialization info missing?");
9865 bool HasNoEffect
= false;
9866 if (CheckSpecializationInstantiationRedecl(Member
->getLocation(),
9867 TSK_ExplicitSpecialization
,
9869 MSInfo
->getTemplateSpecializationKind(),
9870 MSInfo
->getPointOfInstantiation(),
9874 // Check the scope of this explicit specialization.
9875 if (CheckTemplateSpecializationScope(*this,
9877 Instantiation
, Member
->getLocation(),
9881 // Note that this member specialization is an "instantiation of" the
9882 // corresponding member of the original template.
9883 if (auto *MemberFunction
= dyn_cast
<FunctionDecl
>(Member
)) {
9884 FunctionDecl
*InstantiationFunction
= cast
<FunctionDecl
>(Instantiation
);
9885 if (InstantiationFunction
->getTemplateSpecializationKind() ==
9886 TSK_ImplicitInstantiation
) {
9887 // Explicit specializations of member functions of class templates do not
9888 // inherit '=delete' from the member function they are specializing.
9889 if (InstantiationFunction
->isDeleted()) {
9890 // FIXME: This assert will not hold in the presence of modules.
9891 assert(InstantiationFunction
->getCanonicalDecl() ==
9892 InstantiationFunction
);
9893 // FIXME: We need an update record for this AST mutation.
9894 InstantiationFunction
->setDeletedAsWritten(false);
9898 MemberFunction
->setInstantiationOfMemberFunction(
9899 cast
<CXXMethodDecl
>(InstantiatedFrom
), TSK_ExplicitSpecialization
);
9900 } else if (auto *MemberVar
= dyn_cast
<VarDecl
>(Member
)) {
9901 MemberVar
->setInstantiationOfStaticDataMember(
9902 cast
<VarDecl
>(InstantiatedFrom
), TSK_ExplicitSpecialization
);
9903 } else if (auto *MemberClass
= dyn_cast
<CXXRecordDecl
>(Member
)) {
9904 MemberClass
->setInstantiationOfMemberClass(
9905 cast
<CXXRecordDecl
>(InstantiatedFrom
), TSK_ExplicitSpecialization
);
9906 } else if (auto *MemberEnum
= dyn_cast
<EnumDecl
>(Member
)) {
9907 MemberEnum
->setInstantiationOfMemberEnum(
9908 cast
<EnumDecl
>(InstantiatedFrom
), TSK_ExplicitSpecialization
);
9910 llvm_unreachable("unknown member specialization kind");
9913 // Save the caller the trouble of having to figure out which declaration
9914 // this specialization matches.
9916 Previous
.addDecl(FoundInstantiation
);
9920 /// Complete the explicit specialization of a member of a class template by
9921 /// updating the instantiated member to be marked as an explicit specialization.
9923 /// \param OrigD The member declaration instantiated from the template.
9924 /// \param Loc The location of the explicit specialization of the member.
9925 template<typename DeclT
>
9926 static void completeMemberSpecializationImpl(Sema
&S
, DeclT
*OrigD
,
9927 SourceLocation Loc
) {
9928 if (OrigD
->getTemplateSpecializationKind() != TSK_ImplicitInstantiation
)
9931 // FIXME: Inform AST mutation listeners of this AST mutation.
9932 // FIXME: If there are multiple in-class declarations of the member (from
9933 // multiple modules, or a declaration and later definition of a member type),
9934 // should we update all of them?
9935 OrigD
->setTemplateSpecializationKind(TSK_ExplicitSpecialization
);
9936 OrigD
->setLocation(Loc
);
9939 void Sema::CompleteMemberSpecialization(NamedDecl
*Member
,
9940 LookupResult
&Previous
) {
9941 NamedDecl
*Instantiation
= cast
<NamedDecl
>(Member
->getCanonicalDecl());
9942 if (Instantiation
== Member
)
9945 if (auto *Function
= dyn_cast
<CXXMethodDecl
>(Instantiation
))
9946 completeMemberSpecializationImpl(*this, Function
, Member
->getLocation());
9947 else if (auto *Var
= dyn_cast
<VarDecl
>(Instantiation
))
9948 completeMemberSpecializationImpl(*this, Var
, Member
->getLocation());
9949 else if (auto *Record
= dyn_cast
<CXXRecordDecl
>(Instantiation
))
9950 completeMemberSpecializationImpl(*this, Record
, Member
->getLocation());
9951 else if (auto *Enum
= dyn_cast
<EnumDecl
>(Instantiation
))
9952 completeMemberSpecializationImpl(*this, Enum
, Member
->getLocation());
9954 llvm_unreachable("unknown member specialization kind");
9957 /// Check the scope of an explicit instantiation.
9959 /// \returns true if a serious error occurs, false otherwise.
9960 static bool CheckExplicitInstantiationScope(Sema
&S
, NamedDecl
*D
,
9961 SourceLocation InstLoc
,
9962 bool WasQualifiedName
) {
9963 DeclContext
*OrigContext
= D
->getDeclContext()->getEnclosingNamespaceContext();
9964 DeclContext
*CurContext
= S
.CurContext
->getRedeclContext();
9966 if (CurContext
->isRecord()) {
9967 S
.Diag(InstLoc
, diag::err_explicit_instantiation_in_class
)
9972 // C++11 [temp.explicit]p3:
9973 // An explicit instantiation shall appear in an enclosing namespace of its
9974 // template. If the name declared in the explicit instantiation is an
9975 // unqualified name, the explicit instantiation shall appear in the
9976 // namespace where its template is declared or, if that namespace is inline
9977 // (7.3.1), any namespace from its enclosing namespace set.
9979 // This is DR275, which we do not retroactively apply to C++98/03.
9980 if (WasQualifiedName
) {
9981 if (CurContext
->Encloses(OrigContext
))
9984 if (CurContext
->InEnclosingNamespaceSetOf(OrigContext
))
9988 if (NamespaceDecl
*NS
= dyn_cast
<NamespaceDecl
>(OrigContext
)) {
9989 if (WasQualifiedName
)
9991 S
.getLangOpts().CPlusPlus11
?
9992 diag::err_explicit_instantiation_out_of_scope
:
9993 diag::warn_explicit_instantiation_out_of_scope_0x
)
9997 S
.getLangOpts().CPlusPlus11
?
9998 diag::err_explicit_instantiation_unqualified_wrong_namespace
:
9999 diag::warn_explicit_instantiation_unqualified_wrong_namespace_0x
)
10003 S
.getLangOpts().CPlusPlus11
?
10004 diag::err_explicit_instantiation_must_be_global
:
10005 diag::warn_explicit_instantiation_must_be_global_0x
)
10007 S
.Diag(D
->getLocation(), diag::note_explicit_instantiation_here
);
10011 /// Common checks for whether an explicit instantiation of \p D is valid.
10012 static bool CheckExplicitInstantiation(Sema
&S
, NamedDecl
*D
,
10013 SourceLocation InstLoc
,
10014 bool WasQualifiedName
,
10015 TemplateSpecializationKind TSK
) {
10016 // C++ [temp.explicit]p13:
10017 // An explicit instantiation declaration shall not name a specialization of
10018 // a template with internal linkage.
10019 if (TSK
== TSK_ExplicitInstantiationDeclaration
&&
10020 D
->getFormalLinkage() == Linkage::Internal
) {
10021 S
.Diag(InstLoc
, diag::err_explicit_instantiation_internal_linkage
) << D
;
10025 // C++11 [temp.explicit]p3: [DR 275]
10026 // An explicit instantiation shall appear in an enclosing namespace of its
10028 if (CheckExplicitInstantiationScope(S
, D
, InstLoc
, WasQualifiedName
))
10034 /// Determine whether the given scope specifier has a template-id in it.
10035 static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec
&SS
) {
10039 // C++11 [temp.explicit]p3:
10040 // If the explicit instantiation is for a member function, a member class
10041 // or a static data member of a class template specialization, the name of
10042 // the class template specialization in the qualified-id for the member
10043 // name shall be a simple-template-id.
10045 // C++98 has the same restriction, just worded differently.
10046 for (NestedNameSpecifier
*NNS
= SS
.getScopeRep(); NNS
;
10047 NNS
= NNS
->getPrefix())
10048 if (const Type
*T
= NNS
->getAsType())
10049 if (isa
<TemplateSpecializationType
>(T
))
10055 /// Make a dllexport or dllimport attr on a class template specialization take
10057 static void dllExportImportClassTemplateSpecialization(
10058 Sema
&S
, ClassTemplateSpecializationDecl
*Def
) {
10059 auto *A
= cast_or_null
<InheritableAttr
>(getDLLAttr(Def
));
10060 assert(A
&& "dllExportImportClassTemplateSpecialization called "
10061 "on Def without dllexport or dllimport");
10063 // We reject explicit instantiations in class scope, so there should
10064 // never be any delayed exported classes to worry about.
10065 assert(S
.DelayedDllExportClasses
.empty() &&
10066 "delayed exports present at explicit instantiation");
10067 S
.checkClassLevelDLLAttribute(Def
);
10069 // Propagate attribute to base class templates.
10070 for (auto &B
: Def
->bases()) {
10071 if (auto *BT
= dyn_cast_or_null
<ClassTemplateSpecializationDecl
>(
10072 B
.getType()->getAsCXXRecordDecl()))
10073 S
.propagateDLLAttrToBaseClassTemplate(Def
, A
, BT
, B
.getBeginLoc());
10076 S
.referenceDLLExportedClassMethods();
10079 // Explicit instantiation of a class template specialization
10080 DeclResult
Sema::ActOnExplicitInstantiation(
10081 Scope
*S
, SourceLocation ExternLoc
, SourceLocation TemplateLoc
,
10082 unsigned TagSpec
, SourceLocation KWLoc
, const CXXScopeSpec
&SS
,
10083 TemplateTy TemplateD
, SourceLocation TemplateNameLoc
,
10084 SourceLocation LAngleLoc
, ASTTemplateArgsPtr TemplateArgsIn
,
10085 SourceLocation RAngleLoc
, const ParsedAttributesView
&Attr
) {
10086 // Find the class template we're specializing
10087 TemplateName Name
= TemplateD
.get();
10088 TemplateDecl
*TD
= Name
.getAsTemplateDecl();
10089 // Check that the specialization uses the same tag kind as the
10090 // original template.
10091 TagTypeKind Kind
= TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec
);
10092 assert(Kind
!= TagTypeKind::Enum
&&
10093 "Invalid enum tag in class template explicit instantiation!");
10095 ClassTemplateDecl
*ClassTemplate
= dyn_cast
<ClassTemplateDecl
>(TD
);
10097 if (!ClassTemplate
) {
10098 NonTagKind NTK
= getNonTagTypeDeclKind(TD
, Kind
);
10099 Diag(TemplateNameLoc
, diag::err_tag_reference_non_tag
)
10100 << TD
<< NTK
<< llvm::to_underlying(Kind
);
10101 Diag(TD
->getLocation(), diag::note_previous_use
);
10105 if (!isAcceptableTagRedeclaration(ClassTemplate
->getTemplatedDecl(),
10106 Kind
, /*isDefinition*/false, KWLoc
,
10107 ClassTemplate
->getIdentifier())) {
10108 Diag(KWLoc
, diag::err_use_with_wrong_tag
)
10110 << FixItHint::CreateReplacement(KWLoc
,
10111 ClassTemplate
->getTemplatedDecl()->getKindName());
10112 Diag(ClassTemplate
->getTemplatedDecl()->getLocation(),
10113 diag::note_previous_use
);
10114 Kind
= ClassTemplate
->getTemplatedDecl()->getTagKind();
10117 // C++0x [temp.explicit]p2:
10118 // There are two forms of explicit instantiation: an explicit instantiation
10119 // definition and an explicit instantiation declaration. An explicit
10120 // instantiation declaration begins with the extern keyword. [...]
10121 TemplateSpecializationKind TSK
= ExternLoc
.isInvalid()
10122 ? TSK_ExplicitInstantiationDefinition
10123 : TSK_ExplicitInstantiationDeclaration
;
10125 if (TSK
== TSK_ExplicitInstantiationDeclaration
&&
10126 !Context
.getTargetInfo().getTriple().isWindowsGNUEnvironment()) {
10127 // Check for dllexport class template instantiation declarations,
10128 // except for MinGW mode.
10129 for (const ParsedAttr
&AL
: Attr
) {
10130 if (AL
.getKind() == ParsedAttr::AT_DLLExport
) {
10132 diag::warn_attribute_dllexport_explicit_instantiation_decl
);
10133 Diag(AL
.getLoc(), diag::note_attribute
);
10138 if (auto *A
= ClassTemplate
->getTemplatedDecl()->getAttr
<DLLExportAttr
>()) {
10140 diag::warn_attribute_dllexport_explicit_instantiation_decl
);
10141 Diag(A
->getLocation(), diag::note_attribute
);
10145 // In MSVC mode, dllimported explicit instantiation definitions are treated as
10146 // instantiation declarations for most purposes.
10147 bool DLLImportExplicitInstantiationDef
= false;
10148 if (TSK
== TSK_ExplicitInstantiationDefinition
&&
10149 Context
.getTargetInfo().getCXXABI().isMicrosoft()) {
10150 // Check for dllimport class template instantiation definitions.
10152 ClassTemplate
->getTemplatedDecl()->getAttr
<DLLImportAttr
>();
10153 for (const ParsedAttr
&AL
: Attr
) {
10154 if (AL
.getKind() == ParsedAttr::AT_DLLImport
)
10156 if (AL
.getKind() == ParsedAttr::AT_DLLExport
) {
10157 // dllexport trumps dllimport here.
10163 TSK
= TSK_ExplicitInstantiationDeclaration
;
10164 DLLImportExplicitInstantiationDef
= true;
10168 // Translate the parser's template argument list in our AST format.
10169 TemplateArgumentListInfo
TemplateArgs(LAngleLoc
, RAngleLoc
);
10170 translateTemplateArguments(TemplateArgsIn
, TemplateArgs
);
10172 // Check that the template argument list is well-formed for this
10174 SmallVector
<TemplateArgument
, 4> SugaredConverted
, CanonicalConverted
;
10175 if (CheckTemplateArgumentList(ClassTemplate
, TemplateNameLoc
, TemplateArgs
,
10176 false, SugaredConverted
, CanonicalConverted
,
10177 /*UpdateArgsWithConversions=*/true))
10180 // Find the class template specialization declaration that
10181 // corresponds to these arguments.
10182 void *InsertPos
= nullptr;
10183 ClassTemplateSpecializationDecl
*PrevDecl
=
10184 ClassTemplate
->findSpecialization(CanonicalConverted
, InsertPos
);
10186 TemplateSpecializationKind PrevDecl_TSK
10187 = PrevDecl
? PrevDecl
->getTemplateSpecializationKind() : TSK_Undeclared
;
10189 if (TSK
== TSK_ExplicitInstantiationDefinition
&& PrevDecl
!= nullptr &&
10190 Context
.getTargetInfo().getTriple().isWindowsGNUEnvironment()) {
10191 // Check for dllexport class template instantiation definitions in MinGW
10192 // mode, if a previous declaration of the instantiation was seen.
10193 for (const ParsedAttr
&AL
: Attr
) {
10194 if (AL
.getKind() == ParsedAttr::AT_DLLExport
) {
10196 diag::warn_attribute_dllexport_explicit_instantiation_def
);
10202 if (CheckExplicitInstantiation(*this, ClassTemplate
, TemplateNameLoc
,
10206 ClassTemplateSpecializationDecl
*Specialization
= nullptr;
10208 bool HasNoEffect
= false;
10210 if (CheckSpecializationInstantiationRedecl(TemplateNameLoc
, TSK
,
10211 PrevDecl
, PrevDecl_TSK
,
10212 PrevDecl
->getPointOfInstantiation(),
10216 // Even though HasNoEffect == true means that this explicit instantiation
10217 // has no effect on semantics, we go on to put its syntax in the AST.
10219 if (PrevDecl_TSK
== TSK_ImplicitInstantiation
||
10220 PrevDecl_TSK
== TSK_Undeclared
) {
10221 // Since the only prior class template specialization with these
10222 // arguments was referenced but not declared, reuse that
10223 // declaration node as our own, updating the source location
10224 // for the template name to reflect our new declaration.
10225 // (Other source locations will be updated later.)
10226 Specialization
= PrevDecl
;
10227 Specialization
->setLocation(TemplateNameLoc
);
10228 PrevDecl
= nullptr;
10231 if (PrevDecl_TSK
== TSK_ExplicitInstantiationDeclaration
&&
10232 DLLImportExplicitInstantiationDef
) {
10233 // The new specialization might add a dllimport attribute.
10234 HasNoEffect
= false;
10238 if (!Specialization
) {
10239 // Create a new class template specialization declaration node for
10240 // this explicit specialization.
10241 Specialization
= ClassTemplateSpecializationDecl::Create(
10242 Context
, Kind
, ClassTemplate
->getDeclContext(), KWLoc
, TemplateNameLoc
,
10243 ClassTemplate
, CanonicalConverted
, PrevDecl
);
10244 SetNestedNameSpecifier(*this, Specialization
, SS
);
10246 // A MSInheritanceAttr attached to the previous declaration must be
10247 // propagated to the new node prior to instantiation.
10249 if (const auto *A
= PrevDecl
->getAttr
<MSInheritanceAttr
>()) {
10250 auto *Clone
= A
->clone(getASTContext());
10251 Clone
->setInherited(true);
10252 Specialization
->addAttr(Clone
);
10253 Consumer
.AssignInheritanceModel(Specialization
);
10257 if (!HasNoEffect
&& !PrevDecl
) {
10258 // Insert the new specialization.
10259 ClassTemplate
->AddSpecialization(Specialization
, InsertPos
);
10263 // Build the fully-sugared type for this explicit instantiation as
10264 // the user wrote in the explicit instantiation itself. This means
10265 // that we'll pretty-print the type retrieved from the
10266 // specialization's declaration the way that the user actually wrote
10267 // the explicit instantiation, rather than formatting the name based
10268 // on the "canonical" representation used to store the template
10269 // arguments in the specialization.
10270 TypeSourceInfo
*WrittenTy
10271 = Context
.getTemplateSpecializationTypeInfo(Name
, TemplateNameLoc
,
10273 Context
.getTypeDeclType(Specialization
));
10274 Specialization
->setTypeAsWritten(WrittenTy
);
10276 // Set source locations for keywords.
10277 Specialization
->setExternLoc(ExternLoc
);
10278 Specialization
->setTemplateKeywordLoc(TemplateLoc
);
10279 Specialization
->setBraceRange(SourceRange());
10281 bool PreviouslyDLLExported
= Specialization
->hasAttr
<DLLExportAttr
>();
10282 ProcessDeclAttributeList(S
, Specialization
, Attr
);
10284 // Add the explicit instantiation into its lexical context. However,
10285 // since explicit instantiations are never found by name lookup, we
10286 // just put it into the declaration context directly.
10287 Specialization
->setLexicalDeclContext(CurContext
);
10288 CurContext
->addDecl(Specialization
);
10290 // Syntax is now OK, so return if it has no other effect on semantics.
10292 // Set the template specialization kind.
10293 Specialization
->setTemplateSpecializationKind(TSK
);
10294 return Specialization
;
10297 // C++ [temp.explicit]p3:
10298 // A definition of a class template or class member template
10299 // shall be in scope at the point of the explicit instantiation of
10300 // the class template or class member template.
10302 // This check comes when we actually try to perform the
10304 ClassTemplateSpecializationDecl
*Def
10305 = cast_or_null
<ClassTemplateSpecializationDecl
>(
10306 Specialization
->getDefinition());
10308 InstantiateClassTemplateSpecialization(TemplateNameLoc
, Specialization
, TSK
);
10309 else if (TSK
== TSK_ExplicitInstantiationDefinition
) {
10310 MarkVTableUsed(TemplateNameLoc
, Specialization
, true);
10311 Specialization
->setPointOfInstantiation(Def
->getPointOfInstantiation());
10314 // Instantiate the members of this class template specialization.
10315 Def
= cast_or_null
<ClassTemplateSpecializationDecl
>(
10316 Specialization
->getDefinition());
10318 TemplateSpecializationKind Old_TSK
= Def
->getTemplateSpecializationKind();
10319 // Fix a TSK_ExplicitInstantiationDeclaration followed by a
10320 // TSK_ExplicitInstantiationDefinition
10321 if (Old_TSK
== TSK_ExplicitInstantiationDeclaration
&&
10322 (TSK
== TSK_ExplicitInstantiationDefinition
||
10323 DLLImportExplicitInstantiationDef
)) {
10324 // FIXME: Need to notify the ASTMutationListener that we did this.
10325 Def
->setTemplateSpecializationKind(TSK
);
10327 if (!getDLLAttr(Def
) && getDLLAttr(Specialization
) &&
10328 (Context
.getTargetInfo().shouldDLLImportComdatSymbols() &&
10329 !Context
.getTargetInfo().getTriple().isPS())) {
10330 // An explicit instantiation definition can add a dll attribute to a
10331 // template with a previous instantiation declaration. MinGW doesn't
10333 auto *A
= cast
<InheritableAttr
>(
10334 getDLLAttr(Specialization
)->clone(getASTContext()));
10335 A
->setInherited(true);
10337 dllExportImportClassTemplateSpecialization(*this, Def
);
10341 // Fix a TSK_ImplicitInstantiation followed by a
10342 // TSK_ExplicitInstantiationDefinition
10343 bool NewlyDLLExported
=
10344 !PreviouslyDLLExported
&& Specialization
->hasAttr
<DLLExportAttr
>();
10345 if (Old_TSK
== TSK_ImplicitInstantiation
&& NewlyDLLExported
&&
10346 (Context
.getTargetInfo().shouldDLLImportComdatSymbols() &&
10347 !Context
.getTargetInfo().getTriple().isPS())) {
10348 // An explicit instantiation definition can add a dll attribute to a
10349 // template with a previous implicit instantiation. MinGW doesn't allow
10350 // this. We limit clang to only adding dllexport, to avoid potentially
10351 // strange codegen behavior. For example, if we extend this conditional
10352 // to dllimport, and we have a source file calling a method on an
10353 // implicitly instantiated template class instance and then declaring a
10354 // dllimport explicit instantiation definition for the same template
10355 // class, the codegen for the method call will not respect the dllimport,
10356 // while it will with cl. The Def will already have the DLL attribute,
10357 // since the Def and Specialization will be the same in the case of
10358 // Old_TSK == TSK_ImplicitInstantiation, and we already added the
10359 // attribute to the Specialization; we just need to make it take effect.
10360 assert(Def
== Specialization
&&
10361 "Def and Specialization should match for implicit instantiation");
10362 dllExportImportClassTemplateSpecialization(*this, Def
);
10365 // In MinGW mode, export the template instantiation if the declaration
10366 // was marked dllexport.
10367 if (PrevDecl_TSK
== TSK_ExplicitInstantiationDeclaration
&&
10368 Context
.getTargetInfo().getTriple().isWindowsGNUEnvironment() &&
10369 PrevDecl
->hasAttr
<DLLExportAttr
>()) {
10370 dllExportImportClassTemplateSpecialization(*this, Def
);
10373 // Set the template specialization kind. Make sure it is set before
10374 // instantiating the members which will trigger ASTConsumer callbacks.
10375 Specialization
->setTemplateSpecializationKind(TSK
);
10376 InstantiateClassTemplateSpecializationMembers(TemplateNameLoc
, Def
, TSK
);
10379 // Set the template specialization kind.
10380 Specialization
->setTemplateSpecializationKind(TSK
);
10383 return Specialization
;
10386 // Explicit instantiation of a member class of a class template.
10388 Sema::ActOnExplicitInstantiation(Scope
*S
, SourceLocation ExternLoc
,
10389 SourceLocation TemplateLoc
, unsigned TagSpec
,
10390 SourceLocation KWLoc
, CXXScopeSpec
&SS
,
10391 IdentifierInfo
*Name
, SourceLocation NameLoc
,
10392 const ParsedAttributesView
&Attr
) {
10394 bool Owned
= false;
10395 bool IsDependent
= false;
10396 Decl
*TagD
= ActOnTag(S
, TagSpec
, Sema::TUK_Reference
, KWLoc
, SS
, Name
,
10397 NameLoc
, Attr
, AS_none
, /*ModulePrivateLoc=*/SourceLocation(),
10398 MultiTemplateParamsArg(), Owned
, IsDependent
, SourceLocation(),
10399 false, TypeResult(), /*IsTypeSpecifier*/ false,
10400 /*IsTemplateParamOrArg*/ false, /*OOK=*/OOK_Outside
).get();
10401 assert(!IsDependent
&& "explicit instantiation of dependent name not yet handled");
10406 TagDecl
*Tag
= cast
<TagDecl
>(TagD
);
10407 assert(!Tag
->isEnum() && "shouldn't see enumerations here");
10409 if (Tag
->isInvalidDecl())
10412 CXXRecordDecl
*Record
= cast
<CXXRecordDecl
>(Tag
);
10413 CXXRecordDecl
*Pattern
= Record
->getInstantiatedFromMemberClass();
10415 Diag(TemplateLoc
, diag::err_explicit_instantiation_nontemplate_type
)
10416 << Context
.getTypeDeclType(Record
);
10417 Diag(Record
->getLocation(), diag::note_nontemplate_decl_here
);
10421 // C++0x [temp.explicit]p2:
10422 // If the explicit instantiation is for a class or member class, the
10423 // elaborated-type-specifier in the declaration shall include a
10424 // simple-template-id.
10426 // C++98 has the same restriction, just worded differently.
10427 if (!ScopeSpecifierHasTemplateId(SS
))
10428 Diag(TemplateLoc
, diag::ext_explicit_instantiation_without_qualified_id
)
10429 << Record
<< SS
.getRange();
10431 // C++0x [temp.explicit]p2:
10432 // There are two forms of explicit instantiation: an explicit instantiation
10433 // definition and an explicit instantiation declaration. An explicit
10434 // instantiation declaration begins with the extern keyword. [...]
10435 TemplateSpecializationKind TSK
10436 = ExternLoc
.isInvalid()? TSK_ExplicitInstantiationDefinition
10437 : TSK_ExplicitInstantiationDeclaration
;
10439 CheckExplicitInstantiation(*this, Record
, NameLoc
, true, TSK
);
10441 // Verify that it is okay to explicitly instantiate here.
10442 CXXRecordDecl
*PrevDecl
10443 = cast_or_null
<CXXRecordDecl
>(Record
->getPreviousDecl());
10444 if (!PrevDecl
&& Record
->getDefinition())
10447 MemberSpecializationInfo
*MSInfo
= PrevDecl
->getMemberSpecializationInfo();
10448 bool HasNoEffect
= false;
10449 assert(MSInfo
&& "No member specialization information?");
10450 if (CheckSpecializationInstantiationRedecl(TemplateLoc
, TSK
,
10452 MSInfo
->getTemplateSpecializationKind(),
10453 MSInfo
->getPointOfInstantiation(),
10460 CXXRecordDecl
*RecordDef
10461 = cast_or_null
<CXXRecordDecl
>(Record
->getDefinition());
10463 // C++ [temp.explicit]p3:
10464 // A definition of a member class of a class template shall be in scope
10465 // at the point of an explicit instantiation of the member class.
10467 = cast_or_null
<CXXRecordDecl
>(Pattern
->getDefinition());
10469 Diag(TemplateLoc
, diag::err_explicit_instantiation_undefined_member
)
10470 << 0 << Record
->getDeclName() << Record
->getDeclContext();
10471 Diag(Pattern
->getLocation(), diag::note_forward_declaration
)
10475 if (InstantiateClass(NameLoc
, Record
, Def
,
10476 getTemplateInstantiationArgs(Record
),
10480 RecordDef
= cast_or_null
<CXXRecordDecl
>(Record
->getDefinition());
10486 // Instantiate all of the members of the class.
10487 InstantiateClassMembers(NameLoc
, RecordDef
,
10488 getTemplateInstantiationArgs(Record
), TSK
);
10490 if (TSK
== TSK_ExplicitInstantiationDefinition
)
10491 MarkVTableUsed(NameLoc
, RecordDef
, true);
10493 // FIXME: We don't have any representation for explicit instantiations of
10494 // member classes. Such a representation is not needed for compilation, but it
10495 // should be available for clients that want to see all of the declarations in
10496 // the source code.
10500 DeclResult
Sema::ActOnExplicitInstantiation(Scope
*S
,
10501 SourceLocation ExternLoc
,
10502 SourceLocation TemplateLoc
,
10504 // Explicit instantiations always require a name.
10505 // TODO: check if/when DNInfo should replace Name.
10506 DeclarationNameInfo NameInfo
= GetNameForDeclarator(D
);
10507 DeclarationName Name
= NameInfo
.getName();
10509 if (!D
.isInvalidType())
10510 Diag(D
.getDeclSpec().getBeginLoc(),
10511 diag::err_explicit_instantiation_requires_name
)
10512 << D
.getDeclSpec().getSourceRange() << D
.getSourceRange();
10517 // The scope passed in may not be a decl scope. Zip up the scope tree until
10518 // we find one that is.
10519 while ((S
->getFlags() & Scope::DeclScope
) == 0 ||
10520 (S
->getFlags() & Scope::TemplateParamScope
) != 0)
10521 S
= S
->getParent();
10523 // Determine the type of the declaration.
10524 TypeSourceInfo
*T
= GetTypeForDeclarator(D
, S
);
10525 QualType R
= T
->getType();
10529 // C++ [dcl.stc]p1:
10530 // A storage-class-specifier shall not be specified in [...] an explicit
10531 // instantiation (14.7.2) directive.
10532 if (D
.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef
) {
10533 Diag(D
.getIdentifierLoc(), diag::err_explicit_instantiation_of_typedef
)
10536 } else if (D
.getDeclSpec().getStorageClassSpec()
10537 != DeclSpec::SCS_unspecified
) {
10538 // Complain about then remove the storage class specifier.
10539 Diag(D
.getIdentifierLoc(), diag::err_explicit_instantiation_storage_class
)
10540 << FixItHint::CreateRemoval(D
.getDeclSpec().getStorageClassSpecLoc());
10542 D
.getMutableDeclSpec().ClearStorageClassSpecs();
10545 // C++0x [temp.explicit]p1:
10546 // [...] An explicit instantiation of a function template shall not use the
10547 // inline or constexpr specifiers.
10548 // Presumably, this also applies to member functions of class templates as
10550 if (D
.getDeclSpec().isInlineSpecified())
10551 Diag(D
.getDeclSpec().getInlineSpecLoc(),
10552 getLangOpts().CPlusPlus11
?
10553 diag::err_explicit_instantiation_inline
:
10554 diag::warn_explicit_instantiation_inline_0x
)
10555 << FixItHint::CreateRemoval(D
.getDeclSpec().getInlineSpecLoc());
10556 if (D
.getDeclSpec().hasConstexprSpecifier() && R
->isFunctionType())
10557 // FIXME: Add a fix-it to remove the 'constexpr' and add a 'const' if one is
10558 // not already specified.
10559 Diag(D
.getDeclSpec().getConstexprSpecLoc(),
10560 diag::err_explicit_instantiation_constexpr
);
10562 // A deduction guide is not on the list of entities that can be explicitly
10564 if (Name
.getNameKind() == DeclarationName::CXXDeductionGuideName
) {
10565 Diag(D
.getDeclSpec().getBeginLoc(), diag::err_deduction_guide_specialized
)
10566 << /*explicit instantiation*/ 0;
10570 // C++0x [temp.explicit]p2:
10571 // There are two forms of explicit instantiation: an explicit instantiation
10572 // definition and an explicit instantiation declaration. An explicit
10573 // instantiation declaration begins with the extern keyword. [...]
10574 TemplateSpecializationKind TSK
10575 = ExternLoc
.isInvalid()? TSK_ExplicitInstantiationDefinition
10576 : TSK_ExplicitInstantiationDeclaration
;
10578 LookupResult
Previous(*this, NameInfo
, LookupOrdinaryName
);
10579 LookupParsedName(Previous
, S
, &D
.getCXXScopeSpec());
10581 if (!R
->isFunctionType()) {
10582 // C++ [temp.explicit]p1:
10583 // A [...] static data member of a class template can be explicitly
10584 // instantiated from the member definition associated with its class
10586 // C++1y [temp.explicit]p1:
10587 // A [...] variable [...] template specialization can be explicitly
10588 // instantiated from its template.
10589 if (Previous
.isAmbiguous())
10592 VarDecl
*Prev
= Previous
.getAsSingle
<VarDecl
>();
10593 VarTemplateDecl
*PrevTemplate
= Previous
.getAsSingle
<VarTemplateDecl
>();
10595 if (!PrevTemplate
) {
10596 if (!Prev
|| !Prev
->isStaticDataMember()) {
10597 // We expect to see a static data member here.
10598 Diag(D
.getIdentifierLoc(), diag::err_explicit_instantiation_not_known
)
10600 for (LookupResult::iterator P
= Previous
.begin(), PEnd
= Previous
.end();
10602 Diag((*P
)->getLocation(), diag::note_explicit_instantiation_here
);
10606 if (!Prev
->getInstantiatedFromStaticDataMember()) {
10607 // FIXME: Check for explicit specialization?
10608 Diag(D
.getIdentifierLoc(),
10609 diag::err_explicit_instantiation_data_member_not_instantiated
)
10611 Diag(Prev
->getLocation(), diag::note_explicit_instantiation_here
);
10612 // FIXME: Can we provide a note showing where this was declared?
10616 // Explicitly instantiate a variable template.
10618 // C++1y [dcl.spec.auto]p6:
10619 // ... A program that uses auto or decltype(auto) in a context not
10620 // explicitly allowed in this section is ill-formed.
10622 // This includes auto-typed variable template instantiations.
10623 if (R
->isUndeducedType()) {
10624 Diag(T
->getTypeLoc().getBeginLoc(),
10625 diag::err_auto_not_allowed_var_inst
);
10629 if (D
.getName().getKind() != UnqualifiedIdKind::IK_TemplateId
) {
10630 // C++1y [temp.explicit]p3:
10631 // If the explicit instantiation is for a variable, the unqualified-id
10632 // in the declaration shall be a template-id.
10633 Diag(D
.getIdentifierLoc(),
10634 diag::err_explicit_instantiation_without_template_id
)
10636 Diag(PrevTemplate
->getLocation(),
10637 diag::note_explicit_instantiation_here
);
10641 // Translate the parser's template argument list into our AST format.
10642 TemplateArgumentListInfo TemplateArgs
=
10643 makeTemplateArgumentListInfo(*this, *D
.getName().TemplateId
);
10645 DeclResult Res
= CheckVarTemplateId(PrevTemplate
, TemplateLoc
,
10646 D
.getIdentifierLoc(), TemplateArgs
);
10647 if (Res
.isInvalid())
10650 if (!Res
.isUsable()) {
10651 // We somehow specified dependent template arguments in an explicit
10652 // instantiation. This should probably only happen during error
10654 Diag(D
.getIdentifierLoc(), diag::err_explicit_instantiation_dependent
);
10658 // Ignore access control bits, we don't need them for redeclaration
10660 Prev
= cast
<VarDecl
>(Res
.get());
10663 // C++0x [temp.explicit]p2:
10664 // If the explicit instantiation is for a member function, a member class
10665 // or a static data member of a class template specialization, the name of
10666 // the class template specialization in the qualified-id for the member
10667 // name shall be a simple-template-id.
10669 // C++98 has the same restriction, just worded differently.
10671 // This does not apply to variable template specializations, where the
10672 // template-id is in the unqualified-id instead.
10673 if (!ScopeSpecifierHasTemplateId(D
.getCXXScopeSpec()) && !PrevTemplate
)
10674 Diag(D
.getIdentifierLoc(),
10675 diag::ext_explicit_instantiation_without_qualified_id
)
10676 << Prev
<< D
.getCXXScopeSpec().getRange();
10678 CheckExplicitInstantiation(*this, Prev
, D
.getIdentifierLoc(), true, TSK
);
10680 // Verify that it is okay to explicitly instantiate here.
10681 TemplateSpecializationKind PrevTSK
= Prev
->getTemplateSpecializationKind();
10682 SourceLocation POI
= Prev
->getPointOfInstantiation();
10683 bool HasNoEffect
= false;
10684 if (CheckSpecializationInstantiationRedecl(D
.getIdentifierLoc(), TSK
, Prev
,
10685 PrevTSK
, POI
, HasNoEffect
))
10688 if (!HasNoEffect
) {
10689 // Instantiate static data member or variable template.
10690 Prev
->setTemplateSpecializationKind(TSK
, D
.getIdentifierLoc());
10691 // Merge attributes.
10692 ProcessDeclAttributeList(S
, Prev
, D
.getDeclSpec().getAttributes());
10693 if (TSK
== TSK_ExplicitInstantiationDefinition
)
10694 InstantiateVariableDefinition(D
.getIdentifierLoc(), Prev
);
10697 // Check the new variable specialization against the parsed input.
10698 if (PrevTemplate
&& !Context
.hasSameType(Prev
->getType(), R
)) {
10699 Diag(T
->getTypeLoc().getBeginLoc(),
10700 diag::err_invalid_var_template_spec_type
)
10701 << 0 << PrevTemplate
<< R
<< Prev
->getType();
10702 Diag(PrevTemplate
->getLocation(), diag::note_template_declared_here
)
10703 << 2 << PrevTemplate
->getDeclName();
10707 // FIXME: Create an ExplicitInstantiation node?
10708 return (Decl
*) nullptr;
10711 // If the declarator is a template-id, translate the parser's template
10712 // argument list into our AST format.
10713 bool HasExplicitTemplateArgs
= false;
10714 TemplateArgumentListInfo TemplateArgs
;
10715 if (D
.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
) {
10716 TemplateArgs
= makeTemplateArgumentListInfo(*this, *D
.getName().TemplateId
);
10717 HasExplicitTemplateArgs
= true;
10720 // C++ [temp.explicit]p1:
10721 // A [...] function [...] can be explicitly instantiated from its template.
10722 // A member function [...] of a class template can be explicitly
10723 // instantiated from the member definition associated with its class
10725 UnresolvedSet
<8> TemplateMatches
;
10726 FunctionDecl
*NonTemplateMatch
= nullptr;
10727 TemplateSpecCandidateSet
FailedCandidates(D
.getIdentifierLoc());
10728 for (LookupResult::iterator P
= Previous
.begin(), PEnd
= Previous
.end();
10730 NamedDecl
*Prev
= *P
;
10731 if (!HasExplicitTemplateArgs
) {
10732 if (CXXMethodDecl
*Method
= dyn_cast
<CXXMethodDecl
>(Prev
)) {
10733 QualType Adjusted
= adjustCCAndNoReturn(R
, Method
->getType(),
10734 /*AdjustExceptionSpec*/true);
10735 if (Context
.hasSameUnqualifiedType(Method
->getType(), Adjusted
)) {
10736 if (Method
->getPrimaryTemplate()) {
10737 TemplateMatches
.addDecl(Method
, P
.getAccess());
10739 // FIXME: Can this assert ever happen? Needs a test.
10740 assert(!NonTemplateMatch
&& "Multiple NonTemplateMatches");
10741 NonTemplateMatch
= Method
;
10747 FunctionTemplateDecl
*FunTmpl
= dyn_cast
<FunctionTemplateDecl
>(Prev
);
10751 TemplateDeductionInfo
Info(FailedCandidates
.getLocation());
10752 FunctionDecl
*Specialization
= nullptr;
10753 if (TemplateDeductionResult TDK
10754 = DeduceTemplateArguments(FunTmpl
,
10755 (HasExplicitTemplateArgs
? &TemplateArgs
10757 R
, Specialization
, Info
)) {
10758 // Keep track of almost-matches.
10759 FailedCandidates
.addCandidate()
10760 .set(P
.getPair(), FunTmpl
->getTemplatedDecl(),
10761 MakeDeductionFailureInfo(Context
, TDK
, Info
));
10766 // Target attributes are part of the cuda function signature, so
10767 // the cuda target of the instantiated function must match that of its
10768 // template. Given that C++ template deduction does not take
10769 // target attributes into account, we reject candidates here that
10770 // have a different target.
10771 if (LangOpts
.CUDA
&&
10772 IdentifyCUDATarget(Specialization
,
10773 /* IgnoreImplicitHDAttr = */ true) !=
10774 IdentifyCUDATarget(D
.getDeclSpec().getAttributes())) {
10775 FailedCandidates
.addCandidate().set(
10776 P
.getPair(), FunTmpl
->getTemplatedDecl(),
10777 MakeDeductionFailureInfo(Context
, TDK_CUDATargetMismatch
, Info
));
10781 TemplateMatches
.addDecl(Specialization
, P
.getAccess());
10784 FunctionDecl
*Specialization
= NonTemplateMatch
;
10785 if (!Specialization
) {
10786 // Find the most specialized function template specialization.
10787 UnresolvedSetIterator Result
= getMostSpecialized(
10788 TemplateMatches
.begin(), TemplateMatches
.end(), FailedCandidates
,
10789 D
.getIdentifierLoc(),
10790 PDiag(diag::err_explicit_instantiation_not_known
) << Name
,
10791 PDiag(diag::err_explicit_instantiation_ambiguous
) << Name
,
10792 PDiag(diag::note_explicit_instantiation_candidate
));
10794 if (Result
== TemplateMatches
.end())
10797 // Ignore access control bits, we don't need them for redeclaration checking.
10798 Specialization
= cast
<FunctionDecl
>(*Result
);
10801 // C++11 [except.spec]p4
10802 // In an explicit instantiation an exception-specification may be specified,
10803 // but is not required.
10804 // If an exception-specification is specified in an explicit instantiation
10805 // directive, it shall be compatible with the exception-specifications of
10806 // other declarations of that function.
10807 if (auto *FPT
= R
->getAs
<FunctionProtoType
>())
10808 if (FPT
->hasExceptionSpec()) {
10810 diag::err_mismatched_exception_spec_explicit_instantiation
;
10811 if (getLangOpts().MicrosoftExt
)
10812 DiagID
= diag::ext_mismatched_exception_spec_explicit_instantiation
;
10813 bool Result
= CheckEquivalentExceptionSpec(
10814 PDiag(DiagID
) << Specialization
->getType(),
10815 PDiag(diag::note_explicit_instantiation_here
),
10816 Specialization
->getType()->getAs
<FunctionProtoType
>(),
10817 Specialization
->getLocation(), FPT
, D
.getBeginLoc());
10818 // In Microsoft mode, mismatching exception specifications just cause a
10820 if (!getLangOpts().MicrosoftExt
&& Result
)
10824 if (Specialization
->getTemplateSpecializationKind() == TSK_Undeclared
) {
10825 Diag(D
.getIdentifierLoc(),
10826 diag::err_explicit_instantiation_member_function_not_instantiated
)
10828 << (Specialization
->getTemplateSpecializationKind() ==
10829 TSK_ExplicitSpecialization
);
10830 Diag(Specialization
->getLocation(), diag::note_explicit_instantiation_here
);
10834 FunctionDecl
*PrevDecl
= Specialization
->getPreviousDecl();
10835 if (!PrevDecl
&& Specialization
->isThisDeclarationADefinition())
10836 PrevDecl
= Specialization
;
10839 bool HasNoEffect
= false;
10840 if (CheckSpecializationInstantiationRedecl(D
.getIdentifierLoc(), TSK
,
10842 PrevDecl
->getTemplateSpecializationKind(),
10843 PrevDecl
->getPointOfInstantiation(),
10847 // FIXME: We may still want to build some representation of this
10848 // explicit specialization.
10850 return (Decl
*) nullptr;
10853 // HACK: libc++ has a bug where it attempts to explicitly instantiate the
10855 // valarray<size_t>::valarray(size_t) and
10856 // valarray<size_t>::~valarray()
10857 // that it declared to have internal linkage with the internal_linkage
10858 // attribute. Ignore the explicit instantiation declaration in this case.
10859 if (Specialization
->hasAttr
<InternalLinkageAttr
>() &&
10860 TSK
== TSK_ExplicitInstantiationDeclaration
) {
10861 if (auto *RD
= dyn_cast
<CXXRecordDecl
>(Specialization
->getDeclContext()))
10862 if (RD
->getIdentifier() && RD
->getIdentifier()->isStr("valarray") &&
10863 RD
->isInStdNamespace())
10864 return (Decl
*) nullptr;
10867 ProcessDeclAttributeList(S
, Specialization
, D
.getDeclSpec().getAttributes());
10869 // In MSVC mode, dllimported explicit instantiation definitions are treated as
10870 // instantiation declarations.
10871 if (TSK
== TSK_ExplicitInstantiationDefinition
&&
10872 Specialization
->hasAttr
<DLLImportAttr
>() &&
10873 Context
.getTargetInfo().getCXXABI().isMicrosoft())
10874 TSK
= TSK_ExplicitInstantiationDeclaration
;
10876 Specialization
->setTemplateSpecializationKind(TSK
, D
.getIdentifierLoc());
10878 if (Specialization
->isDefined()) {
10879 // Let the ASTConsumer know that this function has been explicitly
10880 // instantiated now, and its linkage might have changed.
10881 Consumer
.HandleTopLevelDecl(DeclGroupRef(Specialization
));
10882 } else if (TSK
== TSK_ExplicitInstantiationDefinition
)
10883 InstantiateFunctionDefinition(D
.getIdentifierLoc(), Specialization
);
10885 // C++0x [temp.explicit]p2:
10886 // If the explicit instantiation is for a member function, a member class
10887 // or a static data member of a class template specialization, the name of
10888 // the class template specialization in the qualified-id for the member
10889 // name shall be a simple-template-id.
10891 // C++98 has the same restriction, just worded differently.
10892 FunctionTemplateDecl
*FunTmpl
= Specialization
->getPrimaryTemplate();
10893 if (D
.getName().getKind() != UnqualifiedIdKind::IK_TemplateId
&& !FunTmpl
&&
10894 D
.getCXXScopeSpec().isSet() &&
10895 !ScopeSpecifierHasTemplateId(D
.getCXXScopeSpec()))
10896 Diag(D
.getIdentifierLoc(),
10897 diag::ext_explicit_instantiation_without_qualified_id
)
10898 << Specialization
<< D
.getCXXScopeSpec().getRange();
10900 CheckExplicitInstantiation(
10902 FunTmpl
? (NamedDecl
*)FunTmpl
10903 : Specialization
->getInstantiatedFromMemberFunction(),
10904 D
.getIdentifierLoc(), D
.getCXXScopeSpec().isSet(), TSK
);
10906 // FIXME: Create some kind of ExplicitInstantiationDecl here.
10907 return (Decl
*) nullptr;
10911 Sema::ActOnDependentTag(Scope
*S
, unsigned TagSpec
, TagUseKind TUK
,
10912 const CXXScopeSpec
&SS
, IdentifierInfo
*Name
,
10913 SourceLocation TagLoc
, SourceLocation NameLoc
) {
10914 // This has to hold, because SS is expected to be defined.
10915 assert(Name
&& "Expected a name in a dependent tag");
10917 NestedNameSpecifier
*NNS
= SS
.getScopeRep();
10921 TagTypeKind Kind
= TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec
);
10923 if (TUK
== TUK_Declaration
|| TUK
== TUK_Definition
) {
10924 Diag(NameLoc
, diag::err_dependent_tag_decl
)
10925 << (TUK
== TUK_Definition
) << llvm::to_underlying(Kind
)
10930 // Create the resulting type.
10931 ElaboratedTypeKeyword Kwd
= TypeWithKeyword::getKeywordForTagTypeKind(Kind
);
10932 QualType Result
= Context
.getDependentNameType(Kwd
, NNS
, Name
);
10934 // Create type-source location information for this type.
10935 TypeLocBuilder TLB
;
10936 DependentNameTypeLoc TL
= TLB
.push
<DependentNameTypeLoc
>(Result
);
10937 TL
.setElaboratedKeywordLoc(TagLoc
);
10938 TL
.setQualifierLoc(SS
.getWithLocInContext(Context
));
10939 TL
.setNameLoc(NameLoc
);
10940 return CreateParsedType(Result
, TLB
.getTypeSourceInfo(Context
, Result
));
10943 TypeResult
Sema::ActOnTypenameType(Scope
*S
, SourceLocation TypenameLoc
,
10944 const CXXScopeSpec
&SS
,
10945 const IdentifierInfo
&II
,
10946 SourceLocation IdLoc
,
10947 ImplicitTypenameContext IsImplicitTypename
) {
10948 if (SS
.isInvalid())
10951 if (TypenameLoc
.isValid() && S
&& !S
->getTemplateParamParent())
10953 getLangOpts().CPlusPlus11
?
10954 diag::warn_cxx98_compat_typename_outside_of_template
:
10955 diag::ext_typename_outside_of_template
)
10956 << FixItHint::CreateRemoval(TypenameLoc
);
10958 NestedNameSpecifierLoc QualifierLoc
= SS
.getWithLocInContext(Context
);
10959 TypeSourceInfo
*TSI
= nullptr;
10961 CheckTypenameType((TypenameLoc
.isValid() ||
10962 IsImplicitTypename
== ImplicitTypenameContext::Yes
)
10963 ? ElaboratedTypeKeyword::Typename
10964 : ElaboratedTypeKeyword::None
,
10965 TypenameLoc
, QualifierLoc
, II
, IdLoc
, &TSI
,
10966 /*DeducedTSTContext=*/true);
10969 return CreateParsedType(T
, TSI
);
10973 Sema::ActOnTypenameType(Scope
*S
,
10974 SourceLocation TypenameLoc
,
10975 const CXXScopeSpec
&SS
,
10976 SourceLocation TemplateKWLoc
,
10977 TemplateTy TemplateIn
,
10978 IdentifierInfo
*TemplateII
,
10979 SourceLocation TemplateIILoc
,
10980 SourceLocation LAngleLoc
,
10981 ASTTemplateArgsPtr TemplateArgsIn
,
10982 SourceLocation RAngleLoc
) {
10983 if (TypenameLoc
.isValid() && S
&& !S
->getTemplateParamParent())
10985 getLangOpts().CPlusPlus11
?
10986 diag::warn_cxx98_compat_typename_outside_of_template
:
10987 diag::ext_typename_outside_of_template
)
10988 << FixItHint::CreateRemoval(TypenameLoc
);
10990 // Strangely, non-type results are not ignored by this lookup, so the
10991 // program is ill-formed if it finds an injected-class-name.
10992 if (TypenameLoc
.isValid()) {
10994 dyn_cast_or_null
<CXXRecordDecl
>(computeDeclContext(SS
, false));
10995 if (LookupRD
&& LookupRD
->getIdentifier() == TemplateII
) {
10996 Diag(TemplateIILoc
,
10997 diag::ext_out_of_line_qualified_id_type_names_constructor
)
10998 << TemplateII
<< 0 /*injected-class-name used as template name*/
10999 << (TemplateKWLoc
.isValid() ? 1 : 0 /*'template'/'typename' keyword*/);
11003 // Translate the parser's template argument list in our AST format.
11004 TemplateArgumentListInfo
TemplateArgs(LAngleLoc
, RAngleLoc
);
11005 translateTemplateArguments(TemplateArgsIn
, TemplateArgs
);
11007 TemplateName Template
= TemplateIn
.get();
11008 if (DependentTemplateName
*DTN
= Template
.getAsDependentTemplateName()) {
11009 // Construct a dependent template specialization type.
11010 assert(DTN
&& "dependent template has non-dependent name?");
11011 assert(DTN
->getQualifier() == SS
.getScopeRep());
11012 QualType T
= Context
.getDependentTemplateSpecializationType(
11013 ElaboratedTypeKeyword::Typename
, DTN
->getQualifier(),
11014 DTN
->getIdentifier(), TemplateArgs
.arguments());
11016 // Create source-location information for this type.
11017 TypeLocBuilder Builder
;
11018 DependentTemplateSpecializationTypeLoc SpecTL
11019 = Builder
.push
<DependentTemplateSpecializationTypeLoc
>(T
);
11020 SpecTL
.setElaboratedKeywordLoc(TypenameLoc
);
11021 SpecTL
.setQualifierLoc(SS
.getWithLocInContext(Context
));
11022 SpecTL
.setTemplateKeywordLoc(TemplateKWLoc
);
11023 SpecTL
.setTemplateNameLoc(TemplateIILoc
);
11024 SpecTL
.setLAngleLoc(LAngleLoc
);
11025 SpecTL
.setRAngleLoc(RAngleLoc
);
11026 for (unsigned I
= 0, N
= TemplateArgs
.size(); I
!= N
; ++I
)
11027 SpecTL
.setArgLocInfo(I
, TemplateArgs
[I
].getLocInfo());
11028 return CreateParsedType(T
, Builder
.getTypeSourceInfo(Context
, T
));
11031 QualType T
= CheckTemplateIdType(Template
, TemplateIILoc
, TemplateArgs
);
11035 // Provide source-location information for the template specialization type.
11036 TypeLocBuilder Builder
;
11037 TemplateSpecializationTypeLoc SpecTL
11038 = Builder
.push
<TemplateSpecializationTypeLoc
>(T
);
11039 SpecTL
.setTemplateKeywordLoc(TemplateKWLoc
);
11040 SpecTL
.setTemplateNameLoc(TemplateIILoc
);
11041 SpecTL
.setLAngleLoc(LAngleLoc
);
11042 SpecTL
.setRAngleLoc(RAngleLoc
);
11043 for (unsigned I
= 0, N
= TemplateArgs
.size(); I
!= N
; ++I
)
11044 SpecTL
.setArgLocInfo(I
, TemplateArgs
[I
].getLocInfo());
11046 T
= Context
.getElaboratedType(ElaboratedTypeKeyword::Typename
,
11047 SS
.getScopeRep(), T
);
11048 ElaboratedTypeLoc TL
= Builder
.push
<ElaboratedTypeLoc
>(T
);
11049 TL
.setElaboratedKeywordLoc(TypenameLoc
);
11050 TL
.setQualifierLoc(SS
.getWithLocInContext(Context
));
11052 TypeSourceInfo
*TSI
= Builder
.getTypeSourceInfo(Context
, T
);
11053 return CreateParsedType(T
, TSI
);
11057 /// Determine whether this failed name lookup should be treated as being
11058 /// disabled by a usage of std::enable_if.
11059 static bool isEnableIf(NestedNameSpecifierLoc NNS
, const IdentifierInfo
&II
,
11060 SourceRange
&CondRange
, Expr
*&Cond
) {
11061 // We must be looking for a ::type...
11062 if (!II
.isStr("type"))
11065 // ... within an explicitly-written template specialization...
11066 if (!NNS
|| !NNS
.getNestedNameSpecifier()->getAsType())
11068 TypeLoc EnableIfTy
= NNS
.getTypeLoc();
11069 TemplateSpecializationTypeLoc EnableIfTSTLoc
=
11070 EnableIfTy
.getAs
<TemplateSpecializationTypeLoc
>();
11071 if (!EnableIfTSTLoc
|| EnableIfTSTLoc
.getNumArgs() == 0)
11073 const TemplateSpecializationType
*EnableIfTST
= EnableIfTSTLoc
.getTypePtr();
11075 // ... which names a complete class template declaration...
11076 const TemplateDecl
*EnableIfDecl
=
11077 EnableIfTST
->getTemplateName().getAsTemplateDecl();
11078 if (!EnableIfDecl
|| EnableIfTST
->isIncompleteType())
11081 // ... called "enable_if".
11082 const IdentifierInfo
*EnableIfII
=
11083 EnableIfDecl
->getDeclName().getAsIdentifierInfo();
11084 if (!EnableIfII
|| !EnableIfII
->isStr("enable_if"))
11087 // Assume the first template argument is the condition.
11088 CondRange
= EnableIfTSTLoc
.getArgLoc(0).getSourceRange();
11090 // Dig out the condition.
11092 if (EnableIfTSTLoc
.getArgLoc(0).getArgument().getKind()
11093 != TemplateArgument::Expression
)
11096 Cond
= EnableIfTSTLoc
.getArgLoc(0).getSourceExpression();
11098 // Ignore Boolean literals; they add no value.
11099 if (isa
<CXXBoolLiteralExpr
>(Cond
->IgnoreParenCasts()))
11106 Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword
,
11107 SourceLocation KeywordLoc
,
11108 NestedNameSpecifierLoc QualifierLoc
,
11109 const IdentifierInfo
&II
,
11110 SourceLocation IILoc
,
11111 TypeSourceInfo
**TSI
,
11112 bool DeducedTSTContext
) {
11113 QualType T
= CheckTypenameType(Keyword
, KeywordLoc
, QualifierLoc
, II
, IILoc
,
11114 DeducedTSTContext
);
11118 *TSI
= Context
.CreateTypeSourceInfo(T
);
11119 if (isa
<DependentNameType
>(T
)) {
11120 DependentNameTypeLoc TL
=
11121 (*TSI
)->getTypeLoc().castAs
<DependentNameTypeLoc
>();
11122 TL
.setElaboratedKeywordLoc(KeywordLoc
);
11123 TL
.setQualifierLoc(QualifierLoc
);
11124 TL
.setNameLoc(IILoc
);
11126 ElaboratedTypeLoc TL
= (*TSI
)->getTypeLoc().castAs
<ElaboratedTypeLoc
>();
11127 TL
.setElaboratedKeywordLoc(KeywordLoc
);
11128 TL
.setQualifierLoc(QualifierLoc
);
11129 TL
.getNamedTypeLoc().castAs
<TypeSpecTypeLoc
>().setNameLoc(IILoc
);
11134 /// Build the type that describes a C++ typename specifier,
11135 /// e.g., "typename T::type".
11137 Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword
,
11138 SourceLocation KeywordLoc
,
11139 NestedNameSpecifierLoc QualifierLoc
,
11140 const IdentifierInfo
&II
,
11141 SourceLocation IILoc
, bool DeducedTSTContext
) {
11143 SS
.Adopt(QualifierLoc
);
11145 DeclContext
*Ctx
= nullptr;
11146 if (QualifierLoc
) {
11147 Ctx
= computeDeclContext(SS
);
11149 // If the nested-name-specifier is dependent and couldn't be
11150 // resolved to a type, build a typename type.
11151 assert(QualifierLoc
.getNestedNameSpecifier()->isDependent());
11152 return Context
.getDependentNameType(Keyword
,
11153 QualifierLoc
.getNestedNameSpecifier(),
11157 // If the nested-name-specifier refers to the current instantiation,
11158 // the "typename" keyword itself is superfluous. In C++03, the
11159 // program is actually ill-formed. However, DR 382 (in C++0x CD1)
11160 // allows such extraneous "typename" keywords, and we retroactively
11161 // apply this DR to C++03 code with only a warning. In any case we continue.
11163 if (RequireCompleteDeclContext(SS
, Ctx
))
11167 DeclarationName
Name(&II
);
11168 LookupResult
Result(*this, Name
, IILoc
, LookupOrdinaryName
);
11170 LookupQualifiedName(Result
, Ctx
, SS
);
11172 LookupName(Result
, CurScope
);
11173 unsigned DiagID
= 0;
11174 Decl
*Referenced
= nullptr;
11175 switch (Result
.getResultKind()) {
11176 case LookupResult::NotFound
: {
11177 // If we're looking up 'type' within a template named 'enable_if', produce
11178 // a more specific diagnostic.
11179 SourceRange CondRange
;
11180 Expr
*Cond
= nullptr;
11181 if (Ctx
&& isEnableIf(QualifierLoc
, II
, CondRange
, Cond
)) {
11182 // If we have a condition, narrow it down to the specific failed
11186 std::string FailedDescription
;
11187 std::tie(FailedCond
, FailedDescription
) =
11188 findFailedBooleanCondition(Cond
);
11190 Diag(FailedCond
->getExprLoc(),
11191 diag::err_typename_nested_not_found_requirement
)
11192 << FailedDescription
11193 << FailedCond
->getSourceRange();
11197 Diag(CondRange
.getBegin(),
11198 diag::err_typename_nested_not_found_enable_if
)
11199 << Ctx
<< CondRange
;
11203 DiagID
= Ctx
? diag::err_typename_nested_not_found
11204 : diag::err_unknown_typename
;
11208 case LookupResult::FoundUnresolvedValue
: {
11209 // We found a using declaration that is a value. Most likely, the using
11210 // declaration itself is meant to have the 'typename' keyword.
11211 SourceRange
FullRange(KeywordLoc
.isValid() ? KeywordLoc
: SS
.getBeginLoc(),
11213 Diag(IILoc
, diag::err_typename_refers_to_using_value_decl
)
11214 << Name
<< Ctx
<< FullRange
;
11215 if (UnresolvedUsingValueDecl
*Using
11216 = dyn_cast
<UnresolvedUsingValueDecl
>(Result
.getRepresentativeDecl())){
11217 SourceLocation Loc
= Using
->getQualifierLoc().getBeginLoc();
11218 Diag(Loc
, diag::note_using_value_decl_missing_typename
)
11219 << FixItHint::CreateInsertion(Loc
, "typename ");
11222 // Fall through to create a dependent typename type, from which we can recover
11226 case LookupResult::NotFoundInCurrentInstantiation
:
11227 // Okay, it's a member of an unknown instantiation.
11228 return Context
.getDependentNameType(Keyword
,
11229 QualifierLoc
.getNestedNameSpecifier(),
11232 case LookupResult::Found
:
11233 if (TypeDecl
*Type
= dyn_cast
<TypeDecl
>(Result
.getFoundDecl())) {
11234 // C++ [class.qual]p2:
11235 // In a lookup in which function names are not ignored and the
11236 // nested-name-specifier nominates a class C, if the name specified
11237 // after the nested-name-specifier, when looked up in C, is the
11238 // injected-class-name of C [...] then the name is instead considered
11239 // to name the constructor of class C.
11241 // Unlike in an elaborated-type-specifier, function names are not ignored
11242 // in typename-specifier lookup. However, they are ignored in all the
11243 // contexts where we form a typename type with no keyword (that is, in
11244 // mem-initializer-ids, base-specifiers, and elaborated-type-specifiers).
11246 // FIXME: That's not strictly true: mem-initializer-id lookup does not
11247 // ignore functions, but that appears to be an oversight.
11248 auto *LookupRD
= dyn_cast_or_null
<CXXRecordDecl
>(Ctx
);
11249 auto *FoundRD
= dyn_cast
<CXXRecordDecl
>(Type
);
11250 if (Keyword
== ElaboratedTypeKeyword::Typename
&& LookupRD
&& FoundRD
&&
11251 FoundRD
->isInjectedClassName() &&
11252 declaresSameEntity(LookupRD
, cast
<Decl
>(FoundRD
->getParent())))
11253 Diag(IILoc
, diag::ext_out_of_line_qualified_id_type_names_constructor
)
11254 << &II
<< 1 << 0 /*'typename' keyword used*/;
11256 // We found a type. Build an ElaboratedType, since the
11257 // typename-specifier was just sugar.
11258 MarkAnyDeclReferenced(Type
->getLocation(), Type
, /*OdrUse=*/false);
11259 return Context
.getElaboratedType(Keyword
,
11260 QualifierLoc
.getNestedNameSpecifier(),
11261 Context
.getTypeDeclType(Type
));
11264 // C++ [dcl.type.simple]p2:
11265 // A type-specifier of the form
11266 // typename[opt] nested-name-specifier[opt] template-name
11267 // is a placeholder for a deduced class type [...].
11268 if (getLangOpts().CPlusPlus17
) {
11269 if (auto *TD
= getAsTypeTemplateDecl(Result
.getFoundDecl())) {
11270 if (!DeducedTSTContext
) {
11271 QualType
T(QualifierLoc
11272 ? QualifierLoc
.getNestedNameSpecifier()->getAsType()
11275 Diag(IILoc
, diag::err_dependent_deduced_tst
)
11276 << (int)getTemplateNameKindForDiagnostics(TemplateName(TD
)) << T
;
11278 Diag(IILoc
, diag::err_deduced_tst
)
11279 << (int)getTemplateNameKindForDiagnostics(TemplateName(TD
));
11280 NoteTemplateLocation(*TD
);
11283 return Context
.getElaboratedType(
11284 Keyword
, QualifierLoc
.getNestedNameSpecifier(),
11285 Context
.getDeducedTemplateSpecializationType(TemplateName(TD
),
11286 QualType(), false));
11290 DiagID
= Ctx
? diag::err_typename_nested_not_type
11291 : diag::err_typename_not_type
;
11292 Referenced
= Result
.getFoundDecl();
11295 case LookupResult::FoundOverloaded
:
11296 DiagID
= Ctx
? diag::err_typename_nested_not_type
11297 : diag::err_typename_not_type
;
11298 Referenced
= *Result
.begin();
11301 case LookupResult::Ambiguous
:
11305 // If we get here, it's because name lookup did not find a
11306 // type. Emit an appropriate diagnostic and return an error.
11307 SourceRange
FullRange(KeywordLoc
.isValid() ? KeywordLoc
: SS
.getBeginLoc(),
11310 Diag(IILoc
, DiagID
) << FullRange
<< Name
<< Ctx
;
11312 Diag(IILoc
, DiagID
) << FullRange
<< Name
;
11314 Diag(Referenced
->getLocation(),
11315 Ctx
? diag::note_typename_member_refers_here
11316 : diag::note_typename_refers_here
)
11322 // See Sema::RebuildTypeInCurrentInstantiation
11323 class CurrentInstantiationRebuilder
11324 : public TreeTransform
<CurrentInstantiationRebuilder
> {
11325 SourceLocation Loc
;
11326 DeclarationName Entity
;
11329 typedef TreeTransform
<CurrentInstantiationRebuilder
> inherited
;
11331 CurrentInstantiationRebuilder(Sema
&SemaRef
,
11332 SourceLocation Loc
,
11333 DeclarationName Entity
)
11334 : TreeTransform
<CurrentInstantiationRebuilder
>(SemaRef
),
11335 Loc(Loc
), Entity(Entity
) { }
11337 /// Determine whether the given type \p T has already been
11340 /// For the purposes of type reconstruction, a type has already been
11341 /// transformed if it is NULL or if it is not dependent.
11342 bool AlreadyTransformed(QualType T
) {
11343 return T
.isNull() || !T
->isInstantiationDependentType();
11346 /// Returns the location of the entity whose type is being
11348 SourceLocation
getBaseLocation() { return Loc
; }
11350 /// Returns the name of the entity whose type is being rebuilt.
11351 DeclarationName
getBaseEntity() { return Entity
; }
11353 /// Sets the "base" location and entity when that
11354 /// information is known based on another transformation.
11355 void setBase(SourceLocation Loc
, DeclarationName Entity
) {
11357 this->Entity
= Entity
;
11360 ExprResult
TransformLambdaExpr(LambdaExpr
*E
) {
11361 // Lambdas never need to be transformed.
11365 } // end anonymous namespace
11367 /// Rebuilds a type within the context of the current instantiation.
11369 /// The type \p T is part of the type of an out-of-line member definition of
11370 /// a class template (or class template partial specialization) that was parsed
11371 /// and constructed before we entered the scope of the class template (or
11372 /// partial specialization thereof). This routine will rebuild that type now
11373 /// that we have entered the declarator's scope, which may produce different
11374 /// canonical types, e.g.,
11377 /// template<typename T>
11379 /// typedef T* pointer;
11380 /// pointer data();
11383 /// template<typename T>
11384 /// typename X<T>::pointer X<T>::data() { ... }
11387 /// Here, the type "typename X<T>::pointer" will be created as a DependentNameType,
11388 /// since we do not know that we can look into X<T> when we parsed the type.
11389 /// This function will rebuild the type, performing the lookup of "pointer"
11390 /// in X<T> and returning an ElaboratedType whose canonical type is the same
11391 /// as the canonical type of T*, allowing the return types of the out-of-line
11392 /// definition and the declaration to match.
11393 TypeSourceInfo
*Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo
*T
,
11394 SourceLocation Loc
,
11395 DeclarationName Name
) {
11396 if (!T
|| !T
->getType()->isInstantiationDependentType())
11399 CurrentInstantiationRebuilder
Rebuilder(*this, Loc
, Name
);
11400 return Rebuilder
.TransformType(T
);
11403 ExprResult
Sema::RebuildExprInCurrentInstantiation(Expr
*E
) {
11404 CurrentInstantiationRebuilder
Rebuilder(*this, E
->getExprLoc(),
11405 DeclarationName());
11406 return Rebuilder
.TransformExpr(E
);
11409 bool Sema::RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec
&SS
) {
11410 if (SS
.isInvalid())
11413 NestedNameSpecifierLoc QualifierLoc
= SS
.getWithLocInContext(Context
);
11414 CurrentInstantiationRebuilder
Rebuilder(*this, SS
.getRange().getBegin(),
11415 DeclarationName());
11416 NestedNameSpecifierLoc Rebuilt
11417 = Rebuilder
.TransformNestedNameSpecifierLoc(QualifierLoc
);
11425 /// Rebuild the template parameters now that we know we're in a current
11427 bool Sema::RebuildTemplateParamsInCurrentInstantiation(
11428 TemplateParameterList
*Params
) {
11429 for (unsigned I
= 0, N
= Params
->size(); I
!= N
; ++I
) {
11430 Decl
*Param
= Params
->getParam(I
);
11432 // There is nothing to rebuild in a type parameter.
11433 if (isa
<TemplateTypeParmDecl
>(Param
))
11436 // Rebuild the template parameter list of a template template parameter.
11437 if (TemplateTemplateParmDecl
*TTP
11438 = dyn_cast
<TemplateTemplateParmDecl
>(Param
)) {
11439 if (RebuildTemplateParamsInCurrentInstantiation(
11440 TTP
->getTemplateParameters()))
11446 // Rebuild the type of a non-type template parameter.
11447 NonTypeTemplateParmDecl
*NTTP
= cast
<NonTypeTemplateParmDecl
>(Param
);
11448 TypeSourceInfo
*NewTSI
11449 = RebuildTypeInCurrentInstantiation(NTTP
->getTypeSourceInfo(),
11450 NTTP
->getLocation(),
11451 NTTP
->getDeclName());
11455 if (NewTSI
->getType()->isUndeducedType()) {
11456 // C++17 [temp.dep.expr]p3:
11457 // An id-expression is type-dependent if it contains
11458 // - an identifier associated by name lookup with a non-type
11459 // template-parameter declared with a type that contains a
11460 // placeholder type (7.1.7.4),
11461 NewTSI
= SubstAutoTypeSourceInfoDependent(NewTSI
);
11464 if (NewTSI
!= NTTP
->getTypeSourceInfo()) {
11465 NTTP
->setTypeSourceInfo(NewTSI
);
11466 NTTP
->setType(NewTSI
->getType());
11473 /// Produces a formatted string that describes the binding of
11474 /// template parameters to template arguments.
11476 Sema::getTemplateArgumentBindingsText(const TemplateParameterList
*Params
,
11477 const TemplateArgumentList
&Args
) {
11478 return getTemplateArgumentBindingsText(Params
, Args
.data(), Args
.size());
11482 Sema::getTemplateArgumentBindingsText(const TemplateParameterList
*Params
,
11483 const TemplateArgument
*Args
,
11484 unsigned NumArgs
) {
11485 SmallString
<128> Str
;
11486 llvm::raw_svector_ostream
Out(Str
);
11488 if (!Params
|| Params
->size() == 0 || NumArgs
== 0)
11489 return std::string();
11491 for (unsigned I
= 0, N
= Params
->size(); I
!= N
; ++I
) {
11500 if (const IdentifierInfo
*Id
= Params
->getParam(I
)->getIdentifier()) {
11501 Out
<< Id
->getName();
11507 Args
[I
].print(getPrintingPolicy(), Out
,
11508 TemplateParameterList::shouldIncludeTypeForArgument(
11509 getPrintingPolicy(), Params
, I
));
11513 return std::string(Out
.str());
11516 void Sema::MarkAsLateParsedTemplate(FunctionDecl
*FD
, Decl
*FnD
,
11517 CachedTokens
&Toks
) {
11521 auto LPT
= std::make_unique
<LateParsedTemplate
>();
11523 // Take tokens to avoid allocations
11524 LPT
->Toks
.swap(Toks
);
11526 LPT
->FPO
= getCurFPFeatures();
11527 LateParsedTemplateMap
.insert(std::make_pair(FD
, std::move(LPT
)));
11529 FD
->setLateTemplateParsed(true);
11532 void Sema::UnmarkAsLateParsedTemplate(FunctionDecl
*FD
) {
11535 FD
->setLateTemplateParsed(false);
11538 bool Sema::IsInsideALocalClassWithinATemplateFunction() {
11539 DeclContext
*DC
= CurContext
;
11542 if (CXXRecordDecl
*RD
= dyn_cast
<CXXRecordDecl
>(CurContext
)) {
11543 const FunctionDecl
*FD
= RD
->isLocalClass();
11544 return (FD
&& FD
->getTemplatedKind() != FunctionDecl::TK_NonTemplate
);
11545 } else if (DC
->isTranslationUnit() || DC
->isNamespace())
11548 DC
= DC
->getParent();
11554 /// Walk the path from which a declaration was instantiated, and check
11555 /// that every explicit specialization along that path is visible. This enforces
11556 /// C++ [temp.expl.spec]/6:
11558 /// If a template, a member template or a member of a class template is
11559 /// explicitly specialized then that specialization shall be declared before
11560 /// the first use of that specialization that would cause an implicit
11561 /// instantiation to take place, in every translation unit in which such a
11562 /// use occurs; no diagnostic is required.
11564 /// and also C++ [temp.class.spec]/1:
11566 /// A partial specialization shall be declared before the first use of a
11567 /// class template specialization that would make use of the partial
11568 /// specialization as the result of an implicit or explicit instantiation
11569 /// in every translation unit in which such a use occurs; no diagnostic is
11571 class ExplicitSpecializationVisibilityChecker
{
11573 SourceLocation Loc
;
11574 llvm::SmallVector
<Module
*, 8> Modules
;
11575 Sema::AcceptableKind Kind
;
11578 ExplicitSpecializationVisibilityChecker(Sema
&S
, SourceLocation Loc
,
11579 Sema::AcceptableKind Kind
)
11580 : S(S
), Loc(Loc
), Kind(Kind
) {}
11582 void check(NamedDecl
*ND
) {
11583 if (auto *FD
= dyn_cast
<FunctionDecl
>(ND
))
11584 return checkImpl(FD
);
11585 if (auto *RD
= dyn_cast
<CXXRecordDecl
>(ND
))
11586 return checkImpl(RD
);
11587 if (auto *VD
= dyn_cast
<VarDecl
>(ND
))
11588 return checkImpl(VD
);
11589 if (auto *ED
= dyn_cast
<EnumDecl
>(ND
))
11590 return checkImpl(ED
);
11594 void diagnose(NamedDecl
*D
, bool IsPartialSpec
) {
11595 auto Kind
= IsPartialSpec
? Sema::MissingImportKind::PartialSpecialization
11596 : Sema::MissingImportKind::ExplicitSpecialization
;
11597 const bool Recover
= true;
11599 // If we got a custom set of modules (because only a subset of the
11600 // declarations are interesting), use them, otherwise let
11601 // diagnoseMissingImport intelligently pick some.
11602 if (Modules
.empty())
11603 S
.diagnoseMissingImport(Loc
, D
, Kind
, Recover
);
11605 S
.diagnoseMissingImport(Loc
, D
, D
->getLocation(), Modules
, Kind
, Recover
);
11608 bool CheckMemberSpecialization(const NamedDecl
*D
) {
11609 return Kind
== Sema::AcceptableKind::Visible
11610 ? S
.hasVisibleMemberSpecialization(D
)
11611 : S
.hasReachableMemberSpecialization(D
);
11614 bool CheckExplicitSpecialization(const NamedDecl
*D
) {
11615 return Kind
== Sema::AcceptableKind::Visible
11616 ? S
.hasVisibleExplicitSpecialization(D
)
11617 : S
.hasReachableExplicitSpecialization(D
);
11620 bool CheckDeclaration(const NamedDecl
*D
) {
11621 return Kind
== Sema::AcceptableKind::Visible
? S
.hasVisibleDeclaration(D
)
11622 : S
.hasReachableDeclaration(D
);
11625 // Check a specific declaration. There are three problematic cases:
11627 // 1) The declaration is an explicit specialization of a template
11629 // 2) The declaration is an explicit specialization of a member of an
11630 // templated class.
11631 // 3) The declaration is an instantiation of a template, and that template
11632 // is an explicit specialization of a member of a templated class.
11634 // We don't need to go any deeper than that, as the instantiation of the
11635 // surrounding class / etc is not triggered by whatever triggered this
11636 // instantiation, and thus should be checked elsewhere.
11637 template<typename SpecDecl
>
11638 void checkImpl(SpecDecl
*Spec
) {
11639 bool IsHiddenExplicitSpecialization
= false;
11640 if (Spec
->getTemplateSpecializationKind() == TSK_ExplicitSpecialization
) {
11641 IsHiddenExplicitSpecialization
= Spec
->getMemberSpecializationInfo()
11642 ? !CheckMemberSpecialization(Spec
)
11643 : !CheckExplicitSpecialization(Spec
);
11645 checkInstantiated(Spec
);
11648 if (IsHiddenExplicitSpecialization
)
11649 diagnose(Spec
->getMostRecentDecl(), false);
11652 void checkInstantiated(FunctionDecl
*FD
) {
11653 if (auto *TD
= FD
->getPrimaryTemplate())
11657 void checkInstantiated(CXXRecordDecl
*RD
) {
11658 auto *SD
= dyn_cast
<ClassTemplateSpecializationDecl
>(RD
);
11662 auto From
= SD
->getSpecializedTemplateOrPartial();
11663 if (auto *TD
= From
.dyn_cast
<ClassTemplateDecl
*>())
11665 else if (auto *TD
=
11666 From
.dyn_cast
<ClassTemplatePartialSpecializationDecl
*>()) {
11667 if (!CheckDeclaration(TD
))
11668 diagnose(TD
, true);
11673 void checkInstantiated(VarDecl
*RD
) {
11674 auto *SD
= dyn_cast
<VarTemplateSpecializationDecl
>(RD
);
11678 auto From
= SD
->getSpecializedTemplateOrPartial();
11679 if (auto *TD
= From
.dyn_cast
<VarTemplateDecl
*>())
11681 else if (auto *TD
=
11682 From
.dyn_cast
<VarTemplatePartialSpecializationDecl
*>()) {
11683 if (!CheckDeclaration(TD
))
11684 diagnose(TD
, true);
11689 void checkInstantiated(EnumDecl
*FD
) {}
11691 template<typename TemplDecl
>
11692 void checkTemplate(TemplDecl
*TD
) {
11693 if (TD
->isMemberSpecialization()) {
11694 if (!CheckMemberSpecialization(TD
))
11695 diagnose(TD
->getMostRecentDecl(), false);
11699 } // end anonymous namespace
11701 void Sema::checkSpecializationVisibility(SourceLocation Loc
, NamedDecl
*Spec
) {
11702 if (!getLangOpts().Modules
)
11705 ExplicitSpecializationVisibilityChecker(*this, Loc
,
11706 Sema::AcceptableKind::Visible
)
11710 void Sema::checkSpecializationReachability(SourceLocation Loc
,
11712 if (!getLangOpts().CPlusPlusModules
)
11713 return checkSpecializationVisibility(Loc
, Spec
);
11715 ExplicitSpecializationVisibilityChecker(*this, Loc
,
11716 Sema::AcceptableKind::Reachable
)
11720 /// Returns the top most location responsible for the definition of \p N.
11721 /// If \p N is a a template specialization, this is the location
11722 /// of the top of the instantiation stack.
11723 /// Otherwise, the location of \p N is returned.
11724 SourceLocation
Sema::getTopMostPointOfInstantiation(const NamedDecl
*N
) const {
11725 if (!getLangOpts().CPlusPlus
|| CodeSynthesisContexts
.empty())
11726 return N
->getLocation();
11727 if (const auto *FD
= dyn_cast
<FunctionDecl
>(N
)) {
11728 if (!FD
->isFunctionTemplateSpecialization())
11729 return FD
->getLocation();
11730 } else if (!isa
<ClassTemplateSpecializationDecl
,
11731 VarTemplateSpecializationDecl
>(N
)) {
11732 return N
->getLocation();
11734 for (const CodeSynthesisContext
&CSC
: CodeSynthesisContexts
) {
11735 if (!CSC
.isInstantiationRecord() || CSC
.PointOfInstantiation
.isInvalid())
11737 return CSC
.PointOfInstantiation
;
11739 return N
->getLocation();