1 //===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //===----------------------------------------------------------------------===/
9 // This file implements C++ template instantiation for declarations.
11 //===----------------------------------------------------------------------===/
12 #include "clang/Sema/SemaInternal.h"
13 #include "clang/AST/ASTConsumer.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/ASTMutationListener.h"
16 #include "clang/AST/DeclTemplate.h"
17 #include "clang/AST/DeclVisitor.h"
18 #include "clang/AST/DependentDiagnostic.h"
19 #include "clang/AST/Expr.h"
20 #include "clang/AST/ExprCXX.h"
21 #include "clang/AST/PrettyDeclStackTrace.h"
22 #include "clang/AST/TypeLoc.h"
23 #include "clang/Sema/Initialization.h"
24 #include "clang/Sema/Lookup.h"
25 #include "clang/Sema/Template.h"
26 #include "clang/Sema/TemplateInstCallback.h"
28 using namespace clang;
30 static bool isDeclWithinFunction(const Decl *D) {
31 const DeclContext *DC = D->getDeclContext();
32 if (DC->isFunctionOrMethod())
36 return cast<CXXRecordDecl>(DC)->isLocalClass();
41 template<typename DeclT>
42 static bool SubstQualifier(Sema &SemaRef, const DeclT *OldDecl, DeclT *NewDecl,
43 const MultiLevelTemplateArgumentList &TemplateArgs) {
44 if (!OldDecl->getQualifierLoc())
47 assert((NewDecl->getFriendObjectKind() ||
48 !OldDecl->getLexicalDeclContext()->isDependentContext()) &&
49 "non-friend with qualified name defined in dependent context");
50 Sema::ContextRAII SavedContext(
52 const_cast<DeclContext *>(NewDecl->getFriendObjectKind()
53 ? NewDecl->getLexicalDeclContext()
54 : OldDecl->getLexicalDeclContext()));
56 NestedNameSpecifierLoc NewQualifierLoc
57 = SemaRef.SubstNestedNameSpecifierLoc(OldDecl->getQualifierLoc(),
63 NewDecl->setQualifierInfo(NewQualifierLoc);
67 bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
68 DeclaratorDecl *NewDecl) {
69 return ::SubstQualifier(SemaRef, OldDecl, NewDecl, TemplateArgs);
72 bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
74 return ::SubstQualifier(SemaRef, OldDecl, NewDecl, TemplateArgs);
77 // Include attribute instantiation code.
78 #include "clang/Sema/AttrTemplateInstantiate.inc"
80 static void instantiateDependentAlignedAttr(
81 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
82 const AlignedAttr *Aligned, Decl *New, bool IsPackExpansion) {
83 if (Aligned->isAlignmentExpr()) {
84 // The alignment expression is a constant expression.
85 EnterExpressionEvaluationContext Unevaluated(
86 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
87 ExprResult Result = S.SubstExpr(Aligned->getAlignmentExpr(), TemplateArgs);
88 if (!Result.isInvalid())
89 S.AddAlignedAttr(Aligned->getLocation(), New, Result.getAs<Expr>(),
90 Aligned->getSpellingListIndex(), IsPackExpansion);
92 TypeSourceInfo *Result = S.SubstType(Aligned->getAlignmentType(),
93 TemplateArgs, Aligned->getLocation(),
96 S.AddAlignedAttr(Aligned->getLocation(), New, Result,
97 Aligned->getSpellingListIndex(), IsPackExpansion);
101 static void instantiateDependentAlignedAttr(
102 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
103 const AlignedAttr *Aligned, Decl *New) {
104 if (!Aligned->isPackExpansion()) {
105 instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
109 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
110 if (Aligned->isAlignmentExpr())
111 S.collectUnexpandedParameterPacks(Aligned->getAlignmentExpr(),
114 S.collectUnexpandedParameterPacks(Aligned->getAlignmentType()->getTypeLoc(),
116 assert(!Unexpanded.empty() && "Pack expansion without parameter packs?");
118 // Determine whether we can expand this attribute pack yet.
119 bool Expand = true, RetainExpansion = false;
120 Optional<unsigned> NumExpansions;
121 // FIXME: Use the actual location of the ellipsis.
122 SourceLocation EllipsisLoc = Aligned->getLocation();
123 if (S.CheckParameterPacksForExpansion(EllipsisLoc, Aligned->getRange(),
124 Unexpanded, TemplateArgs, Expand,
125 RetainExpansion, NumExpansions))
129 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, -1);
130 instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, true);
132 for (unsigned I = 0; I != *NumExpansions; ++I) {
133 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, I);
134 instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
139 static void instantiateDependentAssumeAlignedAttr(
140 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
141 const AssumeAlignedAttr *Aligned, Decl *New) {
142 // The alignment expression is a constant expression.
143 EnterExpressionEvaluationContext Unevaluated(
144 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
146 Expr *E, *OE = nullptr;
147 ExprResult Result = S.SubstExpr(Aligned->getAlignment(), TemplateArgs);
148 if (Result.isInvalid())
150 E = Result.getAs<Expr>();
152 if (Aligned->getOffset()) {
153 Result = S.SubstExpr(Aligned->getOffset(), TemplateArgs);
154 if (Result.isInvalid())
156 OE = Result.getAs<Expr>();
159 S.AddAssumeAlignedAttr(Aligned->getLocation(), New, E, OE,
160 Aligned->getSpellingListIndex());
163 static void instantiateDependentAlignValueAttr(
164 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
165 const AlignValueAttr *Aligned, Decl *New) {
166 // The alignment expression is a constant expression.
167 EnterExpressionEvaluationContext Unevaluated(
168 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
169 ExprResult Result = S.SubstExpr(Aligned->getAlignment(), TemplateArgs);
170 if (!Result.isInvalid())
171 S.AddAlignValueAttr(Aligned->getLocation(), New, Result.getAs<Expr>(),
172 Aligned->getSpellingListIndex());
175 static void instantiateDependentAllocAlignAttr(
176 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
177 const AllocAlignAttr *Align, Decl *New) {
178 Expr *Param = IntegerLiteral::Create(
180 llvm::APInt(64, Align->getParamIndex().getSourceIndex()),
181 S.getASTContext().UnsignedLongLongTy, Align->getLocation());
182 S.AddAllocAlignAttr(Align->getLocation(), New, Param,
183 Align->getSpellingListIndex());
186 static Expr *instantiateDependentFunctionAttrCondition(
187 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
188 const Attr *A, Expr *OldCond, const Decl *Tmpl, FunctionDecl *New) {
189 Expr *Cond = nullptr;
191 Sema::ContextRAII SwitchContext(S, New);
192 EnterExpressionEvaluationContext Unevaluated(
193 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
194 ExprResult Result = S.SubstExpr(OldCond, TemplateArgs);
195 if (Result.isInvalid())
197 Cond = Result.getAs<Expr>();
199 if (!Cond->isTypeDependent()) {
200 ExprResult Converted = S.PerformContextuallyConvertToBool(Cond);
201 if (Converted.isInvalid())
203 Cond = Converted.get();
206 SmallVector<PartialDiagnosticAt, 8> Diags;
207 if (OldCond->isValueDependent() && !Cond->isValueDependent() &&
208 !Expr::isPotentialConstantExprUnevaluated(Cond, New, Diags)) {
209 S.Diag(A->getLocation(), diag::err_attr_cond_never_constant_expr) << A;
210 for (const auto &P : Diags)
211 S.Diag(P.first, P.second);
217 static void instantiateDependentEnableIfAttr(
218 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
219 const EnableIfAttr *EIA, const Decl *Tmpl, FunctionDecl *New) {
220 Expr *Cond = instantiateDependentFunctionAttrCondition(
221 S, TemplateArgs, EIA, EIA->getCond(), Tmpl, New);
224 New->addAttr(new (S.getASTContext()) EnableIfAttr(
225 EIA->getLocation(), S.getASTContext(), Cond, EIA->getMessage(),
226 EIA->getSpellingListIndex()));
229 static void instantiateDependentDiagnoseIfAttr(
230 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
231 const DiagnoseIfAttr *DIA, const Decl *Tmpl, FunctionDecl *New) {
232 Expr *Cond = instantiateDependentFunctionAttrCondition(
233 S, TemplateArgs, DIA, DIA->getCond(), Tmpl, New);
236 New->addAttr(new (S.getASTContext()) DiagnoseIfAttr(
237 DIA->getLocation(), S.getASTContext(), Cond, DIA->getMessage(),
238 DIA->getDiagnosticType(), DIA->getArgDependent(), New,
239 DIA->getSpellingListIndex()));
242 // Constructs and adds to New a new instance of CUDALaunchBoundsAttr using
243 // template A as the base and arguments from TemplateArgs.
244 static void instantiateDependentCUDALaunchBoundsAttr(
245 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
246 const CUDALaunchBoundsAttr &Attr, Decl *New) {
247 // The alignment expression is a constant expression.
248 EnterExpressionEvaluationContext Unevaluated(
249 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
251 ExprResult Result = S.SubstExpr(Attr.getMaxThreads(), TemplateArgs);
252 if (Result.isInvalid())
254 Expr *MaxThreads = Result.getAs<Expr>();
256 Expr *MinBlocks = nullptr;
257 if (Attr.getMinBlocks()) {
258 Result = S.SubstExpr(Attr.getMinBlocks(), TemplateArgs);
259 if (Result.isInvalid())
261 MinBlocks = Result.getAs<Expr>();
264 S.AddLaunchBoundsAttr(Attr.getLocation(), New, MaxThreads, MinBlocks,
265 Attr.getSpellingListIndex());
269 instantiateDependentModeAttr(Sema &S,
270 const MultiLevelTemplateArgumentList &TemplateArgs,
271 const ModeAttr &Attr, Decl *New) {
272 S.AddModeAttr(Attr.getRange(), New, Attr.getMode(),
273 Attr.getSpellingListIndex(), /*InInstantiation=*/true);
276 /// Instantiation of 'declare simd' attribute and its arguments.
277 static void instantiateOMPDeclareSimdDeclAttr(
278 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
279 const OMPDeclareSimdDeclAttr &Attr, Decl *New) {
280 // Allow 'this' in clauses with varlists.
281 if (auto *FTD = dyn_cast<FunctionTemplateDecl>(New))
282 New = FTD->getTemplatedDecl();
283 auto *FD = cast<FunctionDecl>(New);
284 auto *ThisContext = dyn_cast_or_null<CXXRecordDecl>(FD->getDeclContext());
285 SmallVector<Expr *, 4> Uniforms, Aligneds, Alignments, Linears, Steps;
286 SmallVector<unsigned, 4> LinModifiers;
288 auto &&Subst = [&](Expr *E) -> ExprResult {
289 if (auto *DRE = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()))
290 if (auto *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl())) {
291 Sema::ContextRAII SavedContext(S, FD);
292 LocalInstantiationScope Local(S);
293 if (FD->getNumParams() > PVD->getFunctionScopeIndex())
294 Local.InstantiatedLocal(
295 PVD, FD->getParamDecl(PVD->getFunctionScopeIndex()));
296 return S.SubstExpr(E, TemplateArgs);
298 Sema::CXXThisScopeRAII ThisScope(S, ThisContext, /*TypeQuals=*/0,
299 FD->isCXXInstanceMember());
300 return S.SubstExpr(E, TemplateArgs);
304 if (auto *E = Attr.getSimdlen())
307 if (Attr.uniforms_size() > 0) {
308 for(auto *E : Attr.uniforms()) {
309 ExprResult Inst = Subst(E);
310 if (Inst.isInvalid())
312 Uniforms.push_back(Inst.get());
316 auto AI = Attr.alignments_begin();
317 for (auto *E : Attr.aligneds()) {
318 ExprResult Inst = Subst(E);
319 if (Inst.isInvalid())
321 Aligneds.push_back(Inst.get());
324 Inst = S.SubstExpr(*AI, TemplateArgs);
325 Alignments.push_back(Inst.get());
329 auto SI = Attr.steps_begin();
330 for (auto *E : Attr.linears()) {
331 ExprResult Inst = Subst(E);
332 if (Inst.isInvalid())
334 Linears.push_back(Inst.get());
337 Inst = S.SubstExpr(*SI, TemplateArgs);
338 Steps.push_back(Inst.get());
341 LinModifiers.append(Attr.modifiers_begin(), Attr.modifiers_end());
342 (void)S.ActOnOpenMPDeclareSimdDirective(
343 S.ConvertDeclToDeclGroup(New), Attr.getBranchState(), Simdlen.get(),
344 Uniforms, Aligneds, Alignments, Linears, LinModifiers, Steps,
348 void Sema::InstantiateAttrsForDecl(
349 const MultiLevelTemplateArgumentList &TemplateArgs, const Decl *Tmpl,
350 Decl *New, LateInstantiatedAttrVec *LateAttrs,
351 LocalInstantiationScope *OuterMostScope) {
352 if (NamedDecl *ND = dyn_cast<NamedDecl>(New)) {
353 for (const auto *TmplAttr : Tmpl->attrs()) {
354 // FIXME: If any of the special case versions from InstantiateAttrs become
355 // applicable to template declaration, we'll need to add them here.
356 CXXThisScopeRAII ThisScope(
357 *this, dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext()),
358 /*TypeQuals*/ 0, ND->isCXXInstanceMember());
360 Attr *NewAttr = sema::instantiateTemplateAttributeForDecl(
361 TmplAttr, Context, *this, TemplateArgs);
363 New->addAttr(NewAttr);
368 void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
369 const Decl *Tmpl, Decl *New,
370 LateInstantiatedAttrVec *LateAttrs,
371 LocalInstantiationScope *OuterMostScope) {
372 for (const auto *TmplAttr : Tmpl->attrs()) {
373 // FIXME: This should be generalized to more than just the AlignedAttr.
374 const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr);
375 if (Aligned && Aligned->isAlignmentDependent()) {
376 instantiateDependentAlignedAttr(*this, TemplateArgs, Aligned, New);
380 const AssumeAlignedAttr *AssumeAligned = dyn_cast<AssumeAlignedAttr>(TmplAttr);
382 instantiateDependentAssumeAlignedAttr(*this, TemplateArgs, AssumeAligned, New);
386 const AlignValueAttr *AlignValue = dyn_cast<AlignValueAttr>(TmplAttr);
388 instantiateDependentAlignValueAttr(*this, TemplateArgs, AlignValue, New);
392 if (const auto *AllocAlign = dyn_cast<AllocAlignAttr>(TmplAttr)) {
393 instantiateDependentAllocAlignAttr(*this, TemplateArgs, AllocAlign, New);
398 if (const auto *EnableIf = dyn_cast<EnableIfAttr>(TmplAttr)) {
399 instantiateDependentEnableIfAttr(*this, TemplateArgs, EnableIf, Tmpl,
400 cast<FunctionDecl>(New));
404 if (const auto *DiagnoseIf = dyn_cast<DiagnoseIfAttr>(TmplAttr)) {
405 instantiateDependentDiagnoseIfAttr(*this, TemplateArgs, DiagnoseIf, Tmpl,
406 cast<FunctionDecl>(New));
410 if (const CUDALaunchBoundsAttr *CUDALaunchBounds =
411 dyn_cast<CUDALaunchBoundsAttr>(TmplAttr)) {
412 instantiateDependentCUDALaunchBoundsAttr(*this, TemplateArgs,
413 *CUDALaunchBounds, New);
417 if (const ModeAttr *Mode = dyn_cast<ModeAttr>(TmplAttr)) {
418 instantiateDependentModeAttr(*this, TemplateArgs, *Mode, New);
422 if (const auto *OMPAttr = dyn_cast<OMPDeclareSimdDeclAttr>(TmplAttr)) {
423 instantiateOMPDeclareSimdDeclAttr(*this, TemplateArgs, *OMPAttr, New);
427 // Existing DLL attribute on the instantiation takes precedence.
428 if (TmplAttr->getKind() == attr::DLLExport ||
429 TmplAttr->getKind() == attr::DLLImport) {
430 if (New->hasAttr<DLLExportAttr>() || New->hasAttr<DLLImportAttr>()) {
435 if (auto ABIAttr = dyn_cast<ParameterABIAttr>(TmplAttr)) {
436 AddParameterABIAttr(ABIAttr->getRange(), New, ABIAttr->getABI(),
437 ABIAttr->getSpellingListIndex());
441 if (isa<NSConsumedAttr>(TmplAttr) || isa<CFConsumedAttr>(TmplAttr)) {
442 AddNSConsumedAttr(TmplAttr->getRange(), New,
443 TmplAttr->getSpellingListIndex(),
444 isa<NSConsumedAttr>(TmplAttr),
445 /*template instantiation*/ true);
449 assert(!TmplAttr->isPackExpansion());
450 if (TmplAttr->isLateParsed() && LateAttrs) {
451 // Late parsed attributes must be instantiated and attached after the
452 // enclosing class has been instantiated. See Sema::InstantiateClass.
453 LocalInstantiationScope *Saved = nullptr;
454 if (CurrentInstantiationScope)
455 Saved = CurrentInstantiationScope->cloneScopes(OuterMostScope);
456 LateAttrs->push_back(LateInstantiatedAttribute(TmplAttr, Saved, New));
458 // Allow 'this' within late-parsed attributes.
459 NamedDecl *ND = dyn_cast<NamedDecl>(New);
460 CXXRecordDecl *ThisContext =
461 dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext());
462 CXXThisScopeRAII ThisScope(*this, ThisContext, /*TypeQuals*/0,
463 ND && ND->isCXXInstanceMember());
465 Attr *NewAttr = sema::instantiateTemplateAttribute(TmplAttr, Context,
466 *this, TemplateArgs);
468 New->addAttr(NewAttr);
473 /// Get the previous declaration of a declaration for the purposes of template
474 /// instantiation. If this finds a previous declaration, then the previous
475 /// declaration of the instantiation of D should be an instantiation of the
476 /// result of this function.
477 template<typename DeclT>
478 static DeclT *getPreviousDeclForInstantiation(DeclT *D) {
479 DeclT *Result = D->getPreviousDecl();
481 // If the declaration is within a class, and the previous declaration was
482 // merged from a different definition of that class, then we don't have a
483 // previous declaration for the purpose of template instantiation.
484 if (Result && isa<CXXRecordDecl>(D->getDeclContext()) &&
485 D->getLexicalDeclContext() != Result->getLexicalDeclContext())
492 TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
493 llvm_unreachable("Translation units cannot be instantiated");
497 TemplateDeclInstantiator::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
498 llvm_unreachable("pragma comment cannot be instantiated");
501 Decl *TemplateDeclInstantiator::VisitPragmaDetectMismatchDecl(
502 PragmaDetectMismatchDecl *D) {
503 llvm_unreachable("pragma comment cannot be instantiated");
507 TemplateDeclInstantiator::VisitExternCContextDecl(ExternCContextDecl *D) {
508 llvm_unreachable("extern \"C\" context cannot be instantiated");
512 TemplateDeclInstantiator::VisitLabelDecl(LabelDecl *D) {
513 LabelDecl *Inst = LabelDecl::Create(SemaRef.Context, Owner, D->getLocation(),
515 Owner->addDecl(Inst);
520 TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
521 llvm_unreachable("Namespaces cannot be instantiated");
525 TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
526 NamespaceAliasDecl *Inst
527 = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
528 D->getNamespaceLoc(),
531 D->getQualifierLoc(),
532 D->getTargetNameLoc(),
534 Owner->addDecl(Inst);
538 Decl *TemplateDeclInstantiator::InstantiateTypedefNameDecl(TypedefNameDecl *D,
540 bool Invalid = false;
541 TypeSourceInfo *DI = D->getTypeSourceInfo();
542 if (DI->getType()->isInstantiationDependentType() ||
543 DI->getType()->isVariablyModifiedType()) {
544 DI = SemaRef.SubstType(DI, TemplateArgs,
545 D->getLocation(), D->getDeclName());
548 DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
551 SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
554 // HACK: g++ has a bug where it gets the value kind of ?: wrong.
555 // libstdc++ relies upon this bug in its implementation of common_type.
556 // If we happen to be processing that implementation, fake up the g++ ?:
557 // semantics. See LWG issue 2141 for more information on the bug.
558 const DecltypeType *DT = DI->getType()->getAs<DecltypeType>();
559 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D->getDeclContext());
560 if (DT && RD && isa<ConditionalOperator>(DT->getUnderlyingExpr()) &&
561 DT->isReferenceType() &&
562 RD->getEnclosingNamespaceContext() == SemaRef.getStdNamespace() &&
563 RD->getIdentifier() && RD->getIdentifier()->isStr("common_type") &&
564 D->getIdentifier() && D->getIdentifier()->isStr("type") &&
565 SemaRef.getSourceManager().isInSystemHeader(D->getLocStart()))
566 // Fold it to the (non-reference) type which g++ would have produced.
567 DI = SemaRef.Context.getTrivialTypeSourceInfo(
568 DI->getType().getNonReferenceType());
570 // Create the new typedef
571 TypedefNameDecl *Typedef;
573 Typedef = TypeAliasDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
574 D->getLocation(), D->getIdentifier(), DI);
576 Typedef = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
577 D->getLocation(), D->getIdentifier(), DI);
579 Typedef->setInvalidDecl();
581 // If the old typedef was the name for linkage purposes of an anonymous
582 // tag decl, re-establish that relationship for the new typedef.
583 if (const TagType *oldTagType = D->getUnderlyingType()->getAs<TagType>()) {
584 TagDecl *oldTag = oldTagType->getDecl();
585 if (oldTag->getTypedefNameForAnonDecl() == D && !Invalid) {
586 TagDecl *newTag = DI->getType()->castAs<TagType>()->getDecl();
587 assert(!newTag->hasNameForLinkage());
588 newTag->setTypedefNameForAnonDecl(Typedef);
592 if (TypedefNameDecl *Prev = getPreviousDeclForInstantiation(D)) {
593 NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
598 TypedefNameDecl *InstPrevTypedef = cast<TypedefNameDecl>(InstPrev);
600 // If the typedef types are not identical, reject them.
601 SemaRef.isIncompatibleTypedef(InstPrevTypedef, Typedef);
603 Typedef->setPreviousDecl(InstPrevTypedef);
606 SemaRef.InstantiateAttrs(TemplateArgs, D, Typedef);
608 Typedef->setAccess(D->getAccess());
613 Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
614 Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/false);
616 Owner->addDecl(Typedef);
620 Decl *TemplateDeclInstantiator::VisitTypeAliasDecl(TypeAliasDecl *D) {
621 Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/true);
623 Owner->addDecl(Typedef);
628 TemplateDeclInstantiator::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
629 // Create a local instantiation scope for this type alias template, which
630 // will contain the instantiations of the template parameters.
631 LocalInstantiationScope Scope(SemaRef);
633 TemplateParameterList *TempParams = D->getTemplateParameters();
634 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
638 TypeAliasDecl *Pattern = D->getTemplatedDecl();
640 TypeAliasTemplateDecl *PrevAliasTemplate = nullptr;
641 if (getPreviousDeclForInstantiation<TypedefNameDecl>(Pattern)) {
642 DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
643 if (!Found.empty()) {
644 PrevAliasTemplate = dyn_cast<TypeAliasTemplateDecl>(Found.front());
648 TypeAliasDecl *AliasInst = cast_or_null<TypeAliasDecl>(
649 InstantiateTypedefNameDecl(Pattern, /*IsTypeAlias=*/true));
653 TypeAliasTemplateDecl *Inst
654 = TypeAliasTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
655 D->getDeclName(), InstParams, AliasInst);
656 AliasInst->setDescribedAliasTemplate(Inst);
657 if (PrevAliasTemplate)
658 Inst->setPreviousDecl(PrevAliasTemplate);
660 Inst->setAccess(D->getAccess());
662 if (!PrevAliasTemplate)
663 Inst->setInstantiatedFromMemberTemplate(D);
665 Owner->addDecl(Inst);
670 Decl *TemplateDeclInstantiator::VisitBindingDecl(BindingDecl *D) {
671 auto *NewBD = BindingDecl::Create(SemaRef.Context, Owner, D->getLocation(),
673 NewBD->setReferenced(D->isReferenced());
674 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewBD);
678 Decl *TemplateDeclInstantiator::VisitDecompositionDecl(DecompositionDecl *D) {
679 // Transform the bindings first.
680 SmallVector<BindingDecl*, 16> NewBindings;
681 for (auto *OldBD : D->bindings())
682 NewBindings.push_back(cast<BindingDecl>(VisitBindingDecl(OldBD)));
683 ArrayRef<BindingDecl*> NewBindingArray = NewBindings;
685 auto *NewDD = cast_or_null<DecompositionDecl>(
686 VisitVarDecl(D, /*InstantiatingVarTemplate=*/false, &NewBindingArray));
688 if (!NewDD || NewDD->isInvalidDecl())
689 for (auto *NewBD : NewBindings)
690 NewBD->setInvalidDecl();
695 Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
696 return VisitVarDecl(D, /*InstantiatingVarTemplate=*/false);
699 Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D,
700 bool InstantiatingVarTemplate,
701 ArrayRef<BindingDecl*> *Bindings) {
703 // Do substitution on the type of the declaration
704 TypeSourceInfo *DI = SemaRef.SubstType(
705 D->getTypeSourceInfo(), TemplateArgs, D->getTypeSpecStartLoc(),
706 D->getDeclName(), /*AllowDeducedTST*/true);
710 if (DI->getType()->isFunctionType()) {
711 SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
712 << D->isStaticDataMember() << DI->getType();
716 DeclContext *DC = Owner;
717 if (D->isLocalExternDecl())
718 SemaRef.adjustContextForLocalExternDecl(DC);
720 // Build the instantiated declaration.
723 Var = DecompositionDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
724 D->getLocation(), DI->getType(), DI,
725 D->getStorageClass(), *Bindings);
727 Var = VarDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
728 D->getLocation(), D->getIdentifier(), DI->getType(),
729 DI, D->getStorageClass());
731 // In ARC, infer 'retaining' for variables of retainable type.
732 if (SemaRef.getLangOpts().ObjCAutoRefCount &&
733 SemaRef.inferObjCARCLifetime(Var))
734 Var->setInvalidDecl();
736 // Substitute the nested name specifier, if any.
737 if (SubstQualifier(D, Var))
740 SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs, Owner,
741 StartingScope, InstantiatingVarTemplate);
743 if (D->isNRVOVariable()) {
744 QualType ReturnType = cast<FunctionDecl>(DC)->getReturnType();
745 if (SemaRef.isCopyElisionCandidate(ReturnType, Var, Sema::CES_Strict))
746 Var->setNRVOVariable(true);
749 Var->setImplicit(D->isImplicit());
754 Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
756 = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
757 D->getAccessSpecifierLoc(), D->getColonLoc());
758 Owner->addHiddenDecl(AD);
762 Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
763 bool Invalid = false;
764 TypeSourceInfo *DI = D->getTypeSourceInfo();
765 if (DI->getType()->isInstantiationDependentType() ||
766 DI->getType()->isVariablyModifiedType()) {
767 DI = SemaRef.SubstType(DI, TemplateArgs,
768 D->getLocation(), D->getDeclName());
770 DI = D->getTypeSourceInfo();
772 } else if (DI->getType()->isFunctionType()) {
773 // C++ [temp.arg.type]p3:
774 // If a declaration acquires a function type through a type
775 // dependent on a template-parameter and this causes a
776 // declaration that does not use the syntactic form of a
777 // function declarator to have function type, the program is
779 SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
784 SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
787 Expr *BitWidth = D->getBitWidth();
791 // The bit-width expression is a constant expression.
792 EnterExpressionEvaluationContext Unevaluated(
793 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
795 ExprResult InstantiatedBitWidth
796 = SemaRef.SubstExpr(BitWidth, TemplateArgs);
797 if (InstantiatedBitWidth.isInvalid()) {
801 BitWidth = InstantiatedBitWidth.getAs<Expr>();
804 FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
806 cast<RecordDecl>(Owner),
810 D->getInClassInitStyle(),
811 D->getInnerLocStart(),
815 cast<Decl>(Owner)->setInvalidDecl();
819 SemaRef.InstantiateAttrs(TemplateArgs, D, Field, LateAttrs, StartingScope);
821 if (Field->hasAttrs())
822 SemaRef.CheckAlignasUnderalignment(Field);
825 Field->setInvalidDecl();
827 if (!Field->getDeclName()) {
828 // Keep track of where this decl came from.
829 SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
831 if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
832 if (Parent->isAnonymousStructOrUnion() &&
833 Parent->getRedeclContext()->isFunctionOrMethod())
834 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
837 Field->setImplicit(D->isImplicit());
838 Field->setAccess(D->getAccess());
839 Owner->addDecl(Field);
844 Decl *TemplateDeclInstantiator::VisitMSPropertyDecl(MSPropertyDecl *D) {
845 bool Invalid = false;
846 TypeSourceInfo *DI = D->getTypeSourceInfo();
848 if (DI->getType()->isVariablyModifiedType()) {
849 SemaRef.Diag(D->getLocation(), diag::err_property_is_variably_modified)
852 } else if (DI->getType()->isInstantiationDependentType()) {
853 DI = SemaRef.SubstType(DI, TemplateArgs,
854 D->getLocation(), D->getDeclName());
856 DI = D->getTypeSourceInfo();
858 } else if (DI->getType()->isFunctionType()) {
859 // C++ [temp.arg.type]p3:
860 // If a declaration acquires a function type through a type
861 // dependent on a template-parameter and this causes a
862 // declaration that does not use the syntactic form of a
863 // function declarator to have function type, the program is
865 SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
870 SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
873 MSPropertyDecl *Property = MSPropertyDecl::Create(
874 SemaRef.Context, Owner, D->getLocation(), D->getDeclName(), DI->getType(),
875 DI, D->getLocStart(), D->getGetterId(), D->getSetterId());
877 SemaRef.InstantiateAttrs(TemplateArgs, D, Property, LateAttrs,
881 Property->setInvalidDecl();
883 Property->setAccess(D->getAccess());
884 Owner->addDecl(Property);
889 Decl *TemplateDeclInstantiator::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
890 NamedDecl **NamedChain =
891 new (SemaRef.Context)NamedDecl*[D->getChainingSize()];
894 for (auto *PI : D->chain()) {
895 NamedDecl *Next = SemaRef.FindInstantiatedDecl(D->getLocation(), PI,
900 NamedChain[i++] = Next;
903 QualType T = cast<FieldDecl>(NamedChain[i-1])->getType();
904 IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
905 SemaRef.Context, Owner, D->getLocation(), D->getIdentifier(), T,
906 {NamedChain, D->getChainingSize()});
908 for (const auto *Attr : D->attrs())
909 IndirectField->addAttr(Attr->clone(SemaRef.Context));
911 IndirectField->setImplicit(D->isImplicit());
912 IndirectField->setAccess(D->getAccess());
913 Owner->addDecl(IndirectField);
914 return IndirectField;
917 Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
918 // Handle friend type expressions by simply substituting template
919 // parameters into the pattern type and checking the result.
920 if (TypeSourceInfo *Ty = D->getFriendType()) {
921 TypeSourceInfo *InstTy;
922 // If this is an unsupported friend, don't bother substituting template
923 // arguments into it. The actual type referred to won't be used by any
924 // parts of Clang, and may not be valid for instantiating. Just use the
925 // same info for the instantiated friend.
926 if (D->isUnsupportedFriend()) {
929 InstTy = SemaRef.SubstType(Ty, TemplateArgs,
930 D->getLocation(), DeclarationName());
935 FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getLocStart(),
936 D->getFriendLoc(), InstTy);
940 FD->setAccess(AS_public);
941 FD->setUnsupportedFriend(D->isUnsupportedFriend());
946 NamedDecl *ND = D->getFriendDecl();
947 assert(ND && "friend decl must be a decl or a type!");
949 // All of the Visit implementations for the various potential friend
950 // declarations have to be carefully written to work for friend
951 // objects, with the most important detail being that the target
952 // decl should almost certainly not be placed in Owner.
953 Decl *NewND = Visit(ND);
954 if (!NewND) return nullptr;
957 FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
958 cast<NamedDecl>(NewND), D->getFriendLoc());
959 FD->setAccess(AS_public);
960 FD->setUnsupportedFriend(D->isUnsupportedFriend());
965 Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
966 Expr *AssertExpr = D->getAssertExpr();
968 // The expression in a static assertion is a constant expression.
969 EnterExpressionEvaluationContext Unevaluated(
970 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
972 ExprResult InstantiatedAssertExpr
973 = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
974 if (InstantiatedAssertExpr.isInvalid())
977 return SemaRef.BuildStaticAssertDeclaration(D->getLocation(),
978 InstantiatedAssertExpr.get(),
984 Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
985 EnumDecl *PrevDecl = nullptr;
986 if (EnumDecl *PatternPrev = getPreviousDeclForInstantiation(D)) {
987 NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
990 if (!Prev) return nullptr;
991 PrevDecl = cast<EnumDecl>(Prev);
994 EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
995 D->getLocation(), D->getIdentifier(),
996 PrevDecl, D->isScoped(),
997 D->isScopedUsingClassTag(), D->isFixed());
999 if (TypeSourceInfo *TI = D->getIntegerTypeSourceInfo()) {
1000 // If we have type source information for the underlying type, it means it
1001 // has been explicitly set by the user. Perform substitution on it before
1003 SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
1004 TypeSourceInfo *NewTI = SemaRef.SubstType(TI, TemplateArgs, UnderlyingLoc,
1006 if (!NewTI || SemaRef.CheckEnumUnderlyingType(NewTI))
1007 Enum->setIntegerType(SemaRef.Context.IntTy);
1009 Enum->setIntegerTypeSourceInfo(NewTI);
1011 assert(!D->getIntegerType()->isDependentType()
1012 && "Dependent type without type source info");
1013 Enum->setIntegerType(D->getIntegerType());
1017 SemaRef.InstantiateAttrs(TemplateArgs, D, Enum);
1019 Enum->setInstantiationOfMemberEnum(D, TSK_ImplicitInstantiation);
1020 Enum->setAccess(D->getAccess());
1021 // Forward the mangling number from the template to the instantiated decl.
1022 SemaRef.Context.setManglingNumber(Enum, SemaRef.Context.getManglingNumber(D));
1023 // See if the old tag was defined along with a declarator.
1024 // If it did, mark the new tag as being associated with that declarator.
1025 if (DeclaratorDecl *DD = SemaRef.Context.getDeclaratorForUnnamedTagDecl(D))
1026 SemaRef.Context.addDeclaratorForUnnamedTagDecl(Enum, DD);
1027 // See if the old tag was defined along with a typedef.
1028 // If it did, mark the new tag as being associated with that typedef.
1029 if (TypedefNameDecl *TND = SemaRef.Context.getTypedefNameForUnnamedTagDecl(D))
1030 SemaRef.Context.addTypedefNameForUnnamedTagDecl(Enum, TND);
1031 if (SubstQualifier(D, Enum)) return nullptr;
1032 Owner->addDecl(Enum);
1034 EnumDecl *Def = D->getDefinition();
1035 if (Def && Def != D) {
1036 // If this is an out-of-line definition of an enum member template, check
1037 // that the underlying types match in the instantiation of both
1039 if (TypeSourceInfo *TI = Def->getIntegerTypeSourceInfo()) {
1040 SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
1041 QualType DefnUnderlying =
1042 SemaRef.SubstType(TI->getType(), TemplateArgs,
1043 UnderlyingLoc, DeclarationName());
1044 SemaRef.CheckEnumRedeclaration(Def->getLocation(), Def->isScoped(),
1045 DefnUnderlying, /*IsFixed=*/true, Enum);
1049 // C++11 [temp.inst]p1: The implicit instantiation of a class template
1050 // specialization causes the implicit instantiation of the declarations, but
1051 // not the definitions of scoped member enumerations.
1053 // DR1484 clarifies that enumeration definitions inside of a template
1054 // declaration aren't considered entities that can be separately instantiated
1055 // from the rest of the entity they are declared inside of.
1056 if (isDeclWithinFunction(D) ? D == Def : Def && !Enum->isScoped()) {
1057 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
1058 InstantiateEnumDefinition(Enum, Def);
1064 void TemplateDeclInstantiator::InstantiateEnumDefinition(
1065 EnumDecl *Enum, EnumDecl *Pattern) {
1066 Enum->startDefinition();
1068 // Update the location to refer to the definition.
1069 Enum->setLocation(Pattern->getLocation());
1071 SmallVector<Decl*, 4> Enumerators;
1073 EnumConstantDecl *LastEnumConst = nullptr;
1074 for (auto *EC : Pattern->enumerators()) {
1075 // The specified value for the enumerator.
1076 ExprResult Value((Expr *)nullptr);
1077 if (Expr *UninstValue = EC->getInitExpr()) {
1078 // The enumerator's value expression is a constant expression.
1079 EnterExpressionEvaluationContext Unevaluated(
1080 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
1082 Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
1085 // Drop the initial value and continue.
1086 bool isInvalid = false;
1087 if (Value.isInvalid()) {
1092 EnumConstantDecl *EnumConst
1093 = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
1094 EC->getLocation(), EC->getIdentifier(),
1099 EnumConst->setInvalidDecl();
1100 Enum->setInvalidDecl();
1104 SemaRef.InstantiateAttrs(TemplateArgs, EC, EnumConst);
1106 EnumConst->setAccess(Enum->getAccess());
1107 Enum->addDecl(EnumConst);
1108 Enumerators.push_back(EnumConst);
1109 LastEnumConst = EnumConst;
1111 if (Pattern->getDeclContext()->isFunctionOrMethod() &&
1112 !Enum->isScoped()) {
1113 // If the enumeration is within a function or method, record the enum
1114 // constant as a local.
1115 SemaRef.CurrentInstantiationScope->InstantiatedLocal(EC, EnumConst);
1120 SemaRef.ActOnEnumBody(Enum->getLocation(), Enum->getBraceRange(), Enum,
1121 Enumerators, nullptr, ParsedAttributesView());
1124 Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
1125 llvm_unreachable("EnumConstantDecls can only occur within EnumDecls.");
1129 TemplateDeclInstantiator::VisitBuiltinTemplateDecl(BuiltinTemplateDecl *D) {
1130 llvm_unreachable("BuiltinTemplateDecls cannot be instantiated.");
1133 Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1134 bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1136 // Create a local instantiation scope for this class template, which
1137 // will contain the instantiations of the template parameters.
1138 LocalInstantiationScope Scope(SemaRef);
1139 TemplateParameterList *TempParams = D->getTemplateParameters();
1140 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1144 CXXRecordDecl *Pattern = D->getTemplatedDecl();
1146 // Instantiate the qualifier. We have to do this first in case
1147 // we're a friend declaration, because if we are then we need to put
1148 // the new declaration in the appropriate context.
1149 NestedNameSpecifierLoc QualifierLoc = Pattern->getQualifierLoc();
1151 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1157 CXXRecordDecl *PrevDecl = nullptr;
1158 ClassTemplateDecl *PrevClassTemplate = nullptr;
1160 if (!isFriend && getPreviousDeclForInstantiation(Pattern)) {
1161 DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
1162 if (!Found.empty()) {
1163 PrevClassTemplate = dyn_cast<ClassTemplateDecl>(Found.front());
1164 if (PrevClassTemplate)
1165 PrevDecl = PrevClassTemplate->getTemplatedDecl();
1169 // If this isn't a friend, then it's a member template, in which
1170 // case we just want to build the instantiation in the
1171 // specialization. If it is a friend, we want to build it in
1172 // the appropriate context.
1173 DeclContext *DC = Owner;
1177 SS.Adopt(QualifierLoc);
1178 DC = SemaRef.computeDeclContext(SS);
1179 if (!DC) return nullptr;
1181 DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
1182 Pattern->getDeclContext(),
1186 // Look for a previous declaration of the template in the owning
1188 LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
1189 Sema::LookupOrdinaryName,
1190 SemaRef.forRedeclarationInCurContext());
1191 SemaRef.LookupQualifiedName(R, DC);
1193 if (R.isSingleResult()) {
1194 PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
1195 if (PrevClassTemplate)
1196 PrevDecl = PrevClassTemplate->getTemplatedDecl();
1199 if (!PrevClassTemplate && QualifierLoc) {
1200 SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
1201 << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
1202 << QualifierLoc.getSourceRange();
1206 bool AdoptedPreviousTemplateParams = false;
1207 if (PrevClassTemplate) {
1208 bool Complain = true;
1210 // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
1211 // template for struct std::tr1::__detail::_Map_base, where the
1212 // template parameters of the friend declaration don't match the
1213 // template parameters of the original declaration. In this one
1214 // case, we don't complain about the ill-formed friend
1216 if (isFriend && Pattern->getIdentifier() &&
1217 Pattern->getIdentifier()->isStr("_Map_base") &&
1218 DC->isNamespace() &&
1219 cast<NamespaceDecl>(DC)->getIdentifier() &&
1220 cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
1221 DeclContext *DCParent = DC->getParent();
1222 if (DCParent->isNamespace() &&
1223 cast<NamespaceDecl>(DCParent)->getIdentifier() &&
1224 cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
1225 if (cast<Decl>(DCParent)->isInStdNamespace())
1230 TemplateParameterList *PrevParams
1231 = PrevClassTemplate->getTemplateParameters();
1233 // Make sure the parameter lists match.
1234 if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
1236 Sema::TPL_TemplateMatch)) {
1240 AdoptedPreviousTemplateParams = true;
1241 InstParams = PrevParams;
1244 // Do some additional validation, then merge default arguments
1245 // from the existing declarations.
1246 if (!AdoptedPreviousTemplateParams &&
1247 SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
1248 Sema::TPC_ClassTemplate))
1253 CXXRecordDecl *RecordInst
1254 = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
1255 Pattern->getLocStart(), Pattern->getLocation(),
1256 Pattern->getIdentifier(), PrevDecl,
1257 /*DelayTypeCreation=*/true);
1260 RecordInst->setQualifierInfo(QualifierLoc);
1262 ClassTemplateDecl *Inst
1263 = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
1264 D->getIdentifier(), InstParams, RecordInst);
1265 assert(!(isFriend && Owner->isDependentContext()));
1266 Inst->setPreviousDecl(PrevClassTemplate);
1268 RecordInst->setDescribedClassTemplate(Inst);
1271 if (PrevClassTemplate)
1272 Inst->setAccess(PrevClassTemplate->getAccess());
1274 Inst->setAccess(D->getAccess());
1276 Inst->setObjectOfFriendDecl();
1277 // TODO: do we want to track the instantiation progeny of this
1278 // friend target decl?
1280 Inst->setAccess(D->getAccess());
1281 if (!PrevClassTemplate)
1282 Inst->setInstantiatedFromMemberTemplate(D);
1285 // Trigger creation of the type for the instantiation.
1286 SemaRef.Context.getInjectedClassNameType(RecordInst,
1287 Inst->getInjectedClassNameSpecialization());
1289 // Finish handling of friends.
1291 DC->makeDeclVisibleInContext(Inst);
1292 Inst->setLexicalDeclContext(Owner);
1293 RecordInst->setLexicalDeclContext(Owner);
1297 if (D->isOutOfLine()) {
1298 Inst->setLexicalDeclContext(D->getLexicalDeclContext());
1299 RecordInst->setLexicalDeclContext(D->getLexicalDeclContext());
1302 Owner->addDecl(Inst);
1304 if (!PrevClassTemplate) {
1305 // Queue up any out-of-line partial specializations of this member
1306 // class template; the client will force their instantiation once
1307 // the enclosing class has been instantiated.
1308 SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
1309 D->getPartialSpecializations(PartialSpecs);
1310 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
1311 if (PartialSpecs[I]->getFirstDecl()->isOutOfLine())
1312 OutOfLinePartialSpecs.push_back(std::make_pair(Inst, PartialSpecs[I]));
1319 TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
1320 ClassTemplatePartialSpecializationDecl *D) {
1321 ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
1323 // Lookup the already-instantiated declaration in the instantiation
1324 // of the class template and return that.
1325 DeclContext::lookup_result Found
1326 = Owner->lookup(ClassTemplate->getDeclName());
1330 ClassTemplateDecl *InstClassTemplate
1331 = dyn_cast<ClassTemplateDecl>(Found.front());
1332 if (!InstClassTemplate)
1335 if (ClassTemplatePartialSpecializationDecl *Result
1336 = InstClassTemplate->findPartialSpecInstantiatedFromMember(D))
1339 return InstantiateClassTemplatePartialSpecialization(InstClassTemplate, D);
1342 Decl *TemplateDeclInstantiator::VisitVarTemplateDecl(VarTemplateDecl *D) {
1343 assert(D->getTemplatedDecl()->isStaticDataMember() &&
1344 "Only static data member templates are allowed.");
1346 // Create a local instantiation scope for this variable template, which
1347 // will contain the instantiations of the template parameters.
1348 LocalInstantiationScope Scope(SemaRef);
1349 TemplateParameterList *TempParams = D->getTemplateParameters();
1350 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1354 VarDecl *Pattern = D->getTemplatedDecl();
1355 VarTemplateDecl *PrevVarTemplate = nullptr;
1357 if (getPreviousDeclForInstantiation(Pattern)) {
1358 DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
1360 PrevVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
1364 cast_or_null<VarDecl>(VisitVarDecl(Pattern,
1365 /*InstantiatingVarTemplate=*/true));
1366 if (!VarInst) return nullptr;
1368 DeclContext *DC = Owner;
1370 VarTemplateDecl *Inst = VarTemplateDecl::Create(
1371 SemaRef.Context, DC, D->getLocation(), D->getIdentifier(), InstParams,
1373 VarInst->setDescribedVarTemplate(Inst);
1374 Inst->setPreviousDecl(PrevVarTemplate);
1376 Inst->setAccess(D->getAccess());
1377 if (!PrevVarTemplate)
1378 Inst->setInstantiatedFromMemberTemplate(D);
1380 if (D->isOutOfLine()) {
1381 Inst->setLexicalDeclContext(D->getLexicalDeclContext());
1382 VarInst->setLexicalDeclContext(D->getLexicalDeclContext());
1385 Owner->addDecl(Inst);
1387 if (!PrevVarTemplate) {
1388 // Queue up any out-of-line partial specializations of this member
1389 // variable template; the client will force their instantiation once
1390 // the enclosing class has been instantiated.
1391 SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
1392 D->getPartialSpecializations(PartialSpecs);
1393 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
1394 if (PartialSpecs[I]->getFirstDecl()->isOutOfLine())
1395 OutOfLineVarPartialSpecs.push_back(
1396 std::make_pair(Inst, PartialSpecs[I]));
1402 Decl *TemplateDeclInstantiator::VisitVarTemplatePartialSpecializationDecl(
1403 VarTemplatePartialSpecializationDecl *D) {
1404 assert(D->isStaticDataMember() &&
1405 "Only static data member templates are allowed.");
1407 VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
1409 // Lookup the already-instantiated declaration and return that.
1410 DeclContext::lookup_result Found = Owner->lookup(VarTemplate->getDeclName());
1411 assert(!Found.empty() && "Instantiation found nothing?");
1413 VarTemplateDecl *InstVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
1414 assert(InstVarTemplate && "Instantiation did not find a variable template?");
1416 if (VarTemplatePartialSpecializationDecl *Result =
1417 InstVarTemplate->findPartialSpecInstantiatedFromMember(D))
1420 return InstantiateVarTemplatePartialSpecialization(InstVarTemplate, D);
1424 TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1425 // Create a local instantiation scope for this function template, which
1426 // will contain the instantiations of the template parameters and then get
1427 // merged with the local instantiation scope for the function template
1429 LocalInstantiationScope Scope(SemaRef);
1431 TemplateParameterList *TempParams = D->getTemplateParameters();
1432 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1436 FunctionDecl *Instantiated = nullptr;
1437 if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
1438 Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
1441 Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
1442 D->getTemplatedDecl(),
1448 // Link the instantiated function template declaration to the function
1449 // template from which it was instantiated.
1450 FunctionTemplateDecl *InstTemplate
1451 = Instantiated->getDescribedFunctionTemplate();
1452 InstTemplate->setAccess(D->getAccess());
1453 assert(InstTemplate &&
1454 "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
1456 bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
1458 // Link the instantiation back to the pattern *unless* this is a
1459 // non-definition friend declaration.
1460 if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
1461 !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
1462 InstTemplate->setInstantiatedFromMemberTemplate(D);
1464 // Make declarations visible in the appropriate context.
1466 Owner->addDecl(InstTemplate);
1467 } else if (InstTemplate->getDeclContext()->isRecord() &&
1468 !getPreviousDeclForInstantiation(D)) {
1469 SemaRef.CheckFriendAccess(InstTemplate);
1472 return InstTemplate;
1475 Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
1476 CXXRecordDecl *PrevDecl = nullptr;
1477 if (D->isInjectedClassName())
1478 PrevDecl = cast<CXXRecordDecl>(Owner);
1479 else if (CXXRecordDecl *PatternPrev = getPreviousDeclForInstantiation(D)) {
1480 NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
1483 if (!Prev) return nullptr;
1484 PrevDecl = cast<CXXRecordDecl>(Prev);
1487 CXXRecordDecl *Record
1488 = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
1489 D->getLocStart(), D->getLocation(),
1490 D->getIdentifier(), PrevDecl);
1492 // Substitute the nested name specifier, if any.
1493 if (SubstQualifier(D, Record))
1496 Record->setImplicit(D->isImplicit());
1497 // FIXME: Check against AS_none is an ugly hack to work around the issue that
1498 // the tag decls introduced by friend class declarations don't have an access
1499 // specifier. Remove once this area of the code gets sorted out.
1500 if (D->getAccess() != AS_none)
1501 Record->setAccess(D->getAccess());
1502 if (!D->isInjectedClassName())
1503 Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
1505 // If the original function was part of a friend declaration,
1506 // inherit its namespace state.
1507 if (D->getFriendObjectKind())
1508 Record->setObjectOfFriendDecl();
1510 // Make sure that anonymous structs and unions are recorded.
1511 if (D->isAnonymousStructOrUnion())
1512 Record->setAnonymousStructOrUnion(true);
1514 if (D->isLocalClass())
1515 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
1517 // Forward the mangling number from the template to the instantiated decl.
1518 SemaRef.Context.setManglingNumber(Record,
1519 SemaRef.Context.getManglingNumber(D));
1521 // See if the old tag was defined along with a declarator.
1522 // If it did, mark the new tag as being associated with that declarator.
1523 if (DeclaratorDecl *DD = SemaRef.Context.getDeclaratorForUnnamedTagDecl(D))
1524 SemaRef.Context.addDeclaratorForUnnamedTagDecl(Record, DD);
1526 // See if the old tag was defined along with a typedef.
1527 // If it did, mark the new tag as being associated with that typedef.
1528 if (TypedefNameDecl *TND = SemaRef.Context.getTypedefNameForUnnamedTagDecl(D))
1529 SemaRef.Context.addTypedefNameForUnnamedTagDecl(Record, TND);
1531 Owner->addDecl(Record);
1533 // DR1484 clarifies that the members of a local class are instantiated as part
1534 // of the instantiation of their enclosing entity.
1535 if (D->isCompleteDefinition() && D->isLocalClass()) {
1536 Sema::LocalEagerInstantiationScope LocalInstantiations(SemaRef);
1538 SemaRef.InstantiateClass(D->getLocation(), Record, D, TemplateArgs,
1539 TSK_ImplicitInstantiation,
1542 // For nested local classes, we will instantiate the members when we
1543 // reach the end of the outermost (non-nested) local class.
1544 if (!D->isCXXClassMember())
1545 SemaRef.InstantiateClassMembers(D->getLocation(), Record, TemplateArgs,
1546 TSK_ImplicitInstantiation);
1548 // This class may have local implicit instantiations that need to be
1549 // performed within this scope.
1550 LocalInstantiations.perform();
1553 SemaRef.DiagnoseUnusedNestedTypedefs(Record);
1558 /// Adjust the given function type for an instantiation of the
1559 /// given declaration, to cope with modifications to the function's type that
1560 /// aren't reflected in the type-source information.
1562 /// \param D The declaration we're instantiating.
1563 /// \param TInfo The already-instantiated type.
1564 static QualType adjustFunctionTypeForInstantiation(ASTContext &Context,
1566 TypeSourceInfo *TInfo) {
1567 const FunctionProtoType *OrigFunc
1568 = D->getType()->castAs<FunctionProtoType>();
1569 const FunctionProtoType *NewFunc
1570 = TInfo->getType()->castAs<FunctionProtoType>();
1571 if (OrigFunc->getExtInfo() == NewFunc->getExtInfo())
1572 return TInfo->getType();
1574 FunctionProtoType::ExtProtoInfo NewEPI = NewFunc->getExtProtoInfo();
1575 NewEPI.ExtInfo = OrigFunc->getExtInfo();
1576 return Context.getFunctionType(NewFunc->getReturnType(),
1577 NewFunc->getParamTypes(), NewEPI);
1580 /// Normal class members are of more specific types and therefore
1581 /// don't make it here. This function serves three purposes:
1582 /// 1) instantiating function templates
1583 /// 2) substituting friend declarations
1584 /// 3) substituting deduction guide declarations for nested class templates
1585 Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
1586 TemplateParameterList *TemplateParams) {
1587 // Check whether there is already a function template specialization for
1588 // this declaration.
1589 FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1590 if (FunctionTemplate && !TemplateParams) {
1591 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1593 void *InsertPos = nullptr;
1594 FunctionDecl *SpecFunc
1595 = FunctionTemplate->findSpecialization(Innermost, InsertPos);
1597 // If we already have a function template specialization, return it.
1603 if (FunctionTemplate)
1604 isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1606 isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1608 bool MergeWithParentScope = (TemplateParams != nullptr) ||
1609 Owner->isFunctionOrMethod() ||
1610 !(isa<Decl>(Owner) &&
1611 cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1612 LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1614 SmallVector<ParmVarDecl *, 4> Params;
1615 TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
1618 QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
1620 NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1622 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1628 // If we're instantiating a local function declaration, put the result
1629 // in the enclosing namespace; otherwise we need to find the instantiated
1632 if (D->isLocalExternDecl()) {
1634 SemaRef.adjustContextForLocalExternDecl(DC);
1635 } else if (isFriend && QualifierLoc) {
1637 SS.Adopt(QualifierLoc);
1638 DC = SemaRef.computeDeclContext(SS);
1639 if (!DC) return nullptr;
1641 DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1645 DeclarationNameInfo NameInfo
1646 = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1648 FunctionDecl *Function;
1649 if (auto *DGuide = dyn_cast<CXXDeductionGuideDecl>(D)) {
1650 Function = CXXDeductionGuideDecl::Create(
1651 SemaRef.Context, DC, D->getInnerLocStart(), DGuide->isExplicit(),
1652 NameInfo, T, TInfo, D->getSourceRange().getEnd());
1653 if (DGuide->isCopyDeductionCandidate())
1654 cast<CXXDeductionGuideDecl>(Function)->setIsCopyDeductionCandidate();
1655 Function->setAccess(D->getAccess());
1657 Function = FunctionDecl::Create(
1658 SemaRef.Context, DC, D->getInnerLocStart(), NameInfo, T, TInfo,
1659 D->getCanonicalDecl()->getStorageClass(), D->isInlineSpecified(),
1660 D->hasWrittenPrototype(), D->isConstexpr());
1661 Function->setRangeEnd(D->getSourceRange().getEnd());
1665 Function->setImplicitlyInline();
1668 Function->setQualifierInfo(QualifierLoc);
1670 if (D->isLocalExternDecl())
1671 Function->setLocalExternDecl();
1673 DeclContext *LexicalDC = Owner;
1674 if (!isFriend && D->isOutOfLine() && !D->isLocalExternDecl()) {
1675 assert(D->getDeclContext()->isFileContext());
1676 LexicalDC = D->getDeclContext();
1679 Function->setLexicalDeclContext(LexicalDC);
1681 // Attach the parameters
1682 for (unsigned P = 0; P < Params.size(); ++P)
1684 Params[P]->setOwningFunction(Function);
1685 Function->setParams(Params);
1687 if (TemplateParams) {
1688 // Our resulting instantiation is actually a function template, since we
1689 // are substituting only the outer template parameters. For example, given
1691 // template<typename T>
1693 // template<typename U> friend void f(T, U);
1698 // We are instantiating the friend function template "f" within X<int>,
1699 // which means substituting int for T, but leaving "f" as a friend function
1701 // Build the function template itself.
1702 FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1703 Function->getLocation(),
1704 Function->getDeclName(),
1705 TemplateParams, Function);
1706 Function->setDescribedFunctionTemplate(FunctionTemplate);
1708 FunctionTemplate->setLexicalDeclContext(LexicalDC);
1710 if (isFriend && D->isThisDeclarationADefinition()) {
1711 FunctionTemplate->setInstantiatedFromMemberTemplate(
1712 D->getDescribedFunctionTemplate());
1714 } else if (FunctionTemplate) {
1715 // Record this function template specialization.
1716 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1717 Function->setFunctionTemplateSpecialization(FunctionTemplate,
1718 TemplateArgumentList::CreateCopy(SemaRef.Context,
1720 /*InsertPos=*/nullptr);
1721 } else if (isFriend && D->isThisDeclarationADefinition()) {
1722 // Do not connect the friend to the template unless it's actually a
1723 // definition. We don't want non-template functions to be marked as being
1724 // template instantiations.
1725 Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1728 if (InitFunctionInstantiation(Function, D))
1729 Function->setInvalidDecl();
1731 bool isExplicitSpecialization = false;
1733 LookupResult Previous(
1734 SemaRef, Function->getDeclName(), SourceLocation(),
1735 D->isLocalExternDecl() ? Sema::LookupRedeclarationWithLinkage
1736 : Sema::LookupOrdinaryName,
1737 D->isLocalExternDecl() ? Sema::ForExternalRedeclaration
1738 : SemaRef.forRedeclarationInCurContext());
1740 if (DependentFunctionTemplateSpecializationInfo *Info
1741 = D->getDependentSpecializationInfo()) {
1742 assert(isFriend && "non-friend has dependent specialization info?");
1744 // This needs to be set now for future sanity.
1745 Function->setObjectOfFriendDecl();
1747 // Instantiate the explicit template arguments.
1748 TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1749 Info->getRAngleLoc());
1750 if (SemaRef.Subst(Info->getTemplateArgs(), Info->getNumTemplateArgs(),
1751 ExplicitArgs, TemplateArgs))
1754 // Map the candidate templates to their instantiations.
1755 for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1756 Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1757 Info->getTemplate(I),
1759 if (!Temp) return nullptr;
1761 Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1764 if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1767 Function->setInvalidDecl();
1769 isExplicitSpecialization = true;
1771 } else if (TemplateParams || !FunctionTemplate) {
1772 // Look only into the namespace where the friend would be declared to
1773 // find a previous declaration. This is the innermost enclosing namespace,
1774 // as described in ActOnFriendFunctionDecl.
1775 SemaRef.LookupQualifiedName(Previous, DC);
1777 // In C++, the previous declaration we find might be a tag type
1778 // (class or enum). In this case, the new declaration will hide the
1779 // tag type. Note that this does does not apply if we're declaring a
1780 // typedef (C++ [dcl.typedef]p4).
1781 if (Previous.isSingleTagDecl())
1786 Function->setObjectOfFriendDecl();
1788 SemaRef.CheckFunctionDeclaration(/*Scope*/ nullptr, Function, Previous,
1789 isExplicitSpecialization);
1791 NamedDecl *PrincipalDecl = (TemplateParams
1792 ? cast<NamedDecl>(FunctionTemplate)
1795 // If the original function was part of a friend declaration,
1796 // inherit its namespace state and add it to the owner.
1798 PrincipalDecl->setObjectOfFriendDecl();
1799 DC->makeDeclVisibleInContext(PrincipalDecl);
1801 bool QueuedInstantiation = false;
1803 // C++11 [temp.friend]p4 (DR329):
1804 // When a function is defined in a friend function declaration in a class
1805 // template, the function is instantiated when the function is odr-used.
1806 // The same restrictions on multiple declarations and definitions that
1807 // apply to non-template function declarations and definitions also apply
1808 // to these implicit definitions.
1809 if (D->isThisDeclarationADefinition()) {
1810 SemaRef.CheckForFunctionRedefinition(Function);
1811 if (!Function->isInvalidDecl()) {
1812 for (auto R : Function->redecls()) {
1816 // If some prior declaration of this function has been used, we need
1817 // to instantiate its definition.
1818 if (!QueuedInstantiation && R->isUsed(false)) {
1819 if (MemberSpecializationInfo *MSInfo =
1820 Function->getMemberSpecializationInfo()) {
1821 if (MSInfo->getPointOfInstantiation().isInvalid()) {
1822 SourceLocation Loc = R->getLocation(); // FIXME
1823 MSInfo->setPointOfInstantiation(Loc);
1824 SemaRef.PendingLocalImplicitInstantiations.push_back(
1825 std::make_pair(Function, Loc));
1826 QueuedInstantiation = true;
1834 // Check the template parameter list against the previous declaration. The
1835 // goal here is to pick up default arguments added since the friend was
1836 // declared; we know the template parameter lists match, since otherwise
1837 // we would not have picked this template as the previous declaration.
1838 if (TemplateParams && FunctionTemplate->getPreviousDecl()) {
1839 SemaRef.CheckTemplateParameterList(
1841 FunctionTemplate->getPreviousDecl()->getTemplateParameters(),
1842 Function->isThisDeclarationADefinition()
1843 ? Sema::TPC_FriendFunctionTemplateDefinition
1844 : Sema::TPC_FriendFunctionTemplate);
1848 if (Function->isLocalExternDecl() && !Function->getPreviousDecl())
1849 DC->makeDeclVisibleInContext(PrincipalDecl);
1851 if (Function->isOverloadedOperator() && !DC->isRecord() &&
1852 PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1853 PrincipalDecl->setNonMemberOperator();
1855 assert(!D->isDefaulted() && "only methods should be defaulted");
1860 TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1861 TemplateParameterList *TemplateParams,
1862 bool IsClassScopeSpecialization) {
1863 FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1864 if (FunctionTemplate && !TemplateParams) {
1865 // We are creating a function template specialization from a function
1866 // template. Check whether there is already a function template
1867 // specialization for this particular set of template arguments.
1868 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1870 void *InsertPos = nullptr;
1871 FunctionDecl *SpecFunc
1872 = FunctionTemplate->findSpecialization(Innermost, InsertPos);
1874 // If we already have a function template specialization, return it.
1880 if (FunctionTemplate)
1881 isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1883 isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1885 bool MergeWithParentScope = (TemplateParams != nullptr) ||
1886 !(isa<Decl>(Owner) &&
1887 cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1888 LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1890 // Instantiate enclosing template arguments for friends.
1891 SmallVector<TemplateParameterList *, 4> TempParamLists;
1892 unsigned NumTempParamLists = 0;
1893 if (isFriend && (NumTempParamLists = D->getNumTemplateParameterLists())) {
1894 TempParamLists.resize(NumTempParamLists);
1895 for (unsigned I = 0; I != NumTempParamLists; ++I) {
1896 TemplateParameterList *TempParams = D->getTemplateParameterList(I);
1897 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1900 TempParamLists[I] = InstParams;
1904 SmallVector<ParmVarDecl *, 4> Params;
1905 TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
1908 QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
1910 NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1912 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1918 DeclContext *DC = Owner;
1922 SS.Adopt(QualifierLoc);
1923 DC = SemaRef.computeDeclContext(SS);
1925 if (DC && SemaRef.RequireCompleteDeclContext(SS, DC))
1928 DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1929 D->getDeclContext(),
1932 if (!DC) return nullptr;
1935 // Build the instantiated method declaration.
1936 CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1937 CXXMethodDecl *Method = nullptr;
1939 SourceLocation StartLoc = D->getInnerLocStart();
1940 DeclarationNameInfo NameInfo
1941 = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1942 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1943 Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1944 StartLoc, NameInfo, T, TInfo,
1945 Constructor->isExplicit(),
1946 Constructor->isInlineSpecified(),
1947 false, Constructor->isConstexpr());
1948 Method->setRangeEnd(Constructor->getLocEnd());
1949 } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1950 Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1951 StartLoc, NameInfo, T, TInfo,
1952 Destructor->isInlineSpecified(),
1954 Method->setRangeEnd(Destructor->getLocEnd());
1955 } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1956 Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1957 StartLoc, NameInfo, T, TInfo,
1958 Conversion->isInlineSpecified(),
1959 Conversion->isExplicit(),
1960 Conversion->isConstexpr(),
1961 Conversion->getLocEnd());
1963 StorageClass SC = D->isStatic() ? SC_Static : SC_None;
1964 Method = CXXMethodDecl::Create(SemaRef.Context, Record,
1965 StartLoc, NameInfo, T, TInfo,
1966 SC, D->isInlineSpecified(),
1967 D->isConstexpr(), D->getLocEnd());
1971 Method->setImplicitlyInline();
1974 Method->setQualifierInfo(QualifierLoc);
1976 if (TemplateParams) {
1977 // Our resulting instantiation is actually a function template, since we
1978 // are substituting only the outer template parameters. For example, given
1980 // template<typename T>
1982 // template<typename U> void f(T, U);
1987 // We are instantiating the member template "f" within X<int>, which means
1988 // substituting int for T, but leaving "f" as a member function template.
1989 // Build the function template itself.
1990 FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1991 Method->getLocation(),
1992 Method->getDeclName(),
1993 TemplateParams, Method);
1995 FunctionTemplate->setLexicalDeclContext(Owner);
1996 FunctionTemplate->setObjectOfFriendDecl();
1997 } else if (D->isOutOfLine())
1998 FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1999 Method->setDescribedFunctionTemplate(FunctionTemplate);
2000 } else if (FunctionTemplate) {
2001 // Record this function template specialization.
2002 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
2003 Method->setFunctionTemplateSpecialization(FunctionTemplate,
2004 TemplateArgumentList::CreateCopy(SemaRef.Context,
2006 /*InsertPos=*/nullptr);
2007 } else if (!isFriend) {
2008 // Record that this is an instantiation of a member function.
2009 Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
2012 // If we are instantiating a member function defined
2013 // out-of-line, the instantiation will have the same lexical
2014 // context (which will be a namespace scope) as the template.
2016 if (NumTempParamLists)
2017 Method->setTemplateParameterListsInfo(
2019 llvm::makeArrayRef(TempParamLists.data(), NumTempParamLists));
2021 Method->setLexicalDeclContext(Owner);
2022 Method->setObjectOfFriendDecl();
2023 } else if (D->isOutOfLine())
2024 Method->setLexicalDeclContext(D->getLexicalDeclContext());
2026 // Attach the parameters
2027 for (unsigned P = 0; P < Params.size(); ++P)
2028 Params[P]->setOwningFunction(Method);
2029 Method->setParams(Params);
2031 if (InitMethodInstantiation(Method, D))
2032 Method->setInvalidDecl();
2034 LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
2035 Sema::ForExternalRedeclaration);
2037 if (!FunctionTemplate || TemplateParams || isFriend) {
2038 SemaRef.LookupQualifiedName(Previous, Record);
2040 // In C++, the previous declaration we find might be a tag type
2041 // (class or enum). In this case, the new declaration will hide the
2042 // tag type. Note that this does does not apply if we're declaring a
2043 // typedef (C++ [dcl.typedef]p4).
2044 if (Previous.isSingleTagDecl())
2048 if (!IsClassScopeSpecialization)
2049 SemaRef.CheckFunctionDeclaration(nullptr, Method, Previous, false);
2052 SemaRef.CheckPureMethod(Method, SourceRange());
2054 // Propagate access. For a non-friend declaration, the access is
2055 // whatever we're propagating from. For a friend, it should be the
2056 // previous declaration we just found.
2057 if (isFriend && Method->getPreviousDecl())
2058 Method->setAccess(Method->getPreviousDecl()->getAccess());
2060 Method->setAccess(D->getAccess());
2061 if (FunctionTemplate)
2062 FunctionTemplate->setAccess(Method->getAccess());
2064 SemaRef.CheckOverrideControl(Method);
2066 // If a function is defined as defaulted or deleted, mark it as such now.
2067 if (D->isExplicitlyDefaulted())
2068 SemaRef.SetDeclDefaulted(Method, Method->getLocation());
2069 if (D->isDeletedAsWritten())
2070 SemaRef.SetDeclDeleted(Method, Method->getLocation());
2072 // If there's a function template, let our caller handle it.
2073 if (FunctionTemplate) {
2076 // Don't hide a (potentially) valid declaration with an invalid one.
2077 } else if (Method->isInvalidDecl() && !Previous.empty()) {
2080 // Otherwise, check access to friends and make them visible.
2081 } else if (isFriend) {
2082 // We only need to re-check access for methods which we didn't
2083 // manage to match during parsing.
2084 if (!D->getPreviousDecl())
2085 SemaRef.CheckFriendAccess(Method);
2087 Record->makeDeclVisibleInContext(Method);
2089 // Otherwise, add the declaration. We don't need to do this for
2090 // class-scope specializations because we'll have matched them with
2091 // the appropriate template.
2092 } else if (!IsClassScopeSpecialization) {
2093 Owner->addDecl(Method);
2099 Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
2100 return VisitCXXMethodDecl(D);
2103 Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
2104 return VisitCXXMethodDecl(D);
2107 Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
2108 return VisitCXXMethodDecl(D);
2111 Decl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
2112 return SemaRef.SubstParmVarDecl(D, TemplateArgs, /*indexAdjustment*/ 0, None,
2113 /*ExpectParameterPack=*/ false);
2116 Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
2117 TemplateTypeParmDecl *D) {
2118 // TODO: don't always clone when decls are refcounted.
2119 assert(D->getTypeForDecl()->isTemplateTypeParmType());
2121 TemplateTypeParmDecl *Inst = TemplateTypeParmDecl::Create(
2122 SemaRef.Context, Owner, D->getLocStart(), D->getLocation(),
2123 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(), D->getIndex(),
2124 D->getIdentifier(), D->wasDeclaredWithTypename(), D->isParameterPack());
2125 Inst->setAccess(AS_public);
2127 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2128 TypeSourceInfo *InstantiatedDefaultArg =
2129 SemaRef.SubstType(D->getDefaultArgumentInfo(), TemplateArgs,
2130 D->getDefaultArgumentLoc(), D->getDeclName());
2131 if (InstantiatedDefaultArg)
2132 Inst->setDefaultArgument(InstantiatedDefaultArg);
2135 // Introduce this template parameter's instantiation into the instantiation
2137 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
2142 Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
2143 NonTypeTemplateParmDecl *D) {
2144 // Substitute into the type of the non-type template parameter.
2145 TypeLoc TL = D->getTypeSourceInfo()->getTypeLoc();
2146 SmallVector<TypeSourceInfo *, 4> ExpandedParameterPackTypesAsWritten;
2147 SmallVector<QualType, 4> ExpandedParameterPackTypes;
2148 bool IsExpandedParameterPack = false;
2151 bool Invalid = false;
2153 if (D->isExpandedParameterPack()) {
2154 // The non-type template parameter pack is an already-expanded pack
2155 // expansion of types. Substitute into each of the expanded types.
2156 ExpandedParameterPackTypes.reserve(D->getNumExpansionTypes());
2157 ExpandedParameterPackTypesAsWritten.reserve(D->getNumExpansionTypes());
2158 for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
2159 TypeSourceInfo *NewDI =
2160 SemaRef.SubstType(D->getExpansionTypeSourceInfo(I), TemplateArgs,
2161 D->getLocation(), D->getDeclName());
2166 SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
2170 ExpandedParameterPackTypesAsWritten.push_back(NewDI);
2171 ExpandedParameterPackTypes.push_back(NewT);
2174 IsExpandedParameterPack = true;
2175 DI = D->getTypeSourceInfo();
2177 } else if (D->isPackExpansion()) {
2178 // The non-type template parameter pack's type is a pack expansion of types.
2179 // Determine whether we need to expand this parameter pack into separate
2181 PackExpansionTypeLoc Expansion = TL.castAs<PackExpansionTypeLoc>();
2182 TypeLoc Pattern = Expansion.getPatternLoc();
2183 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2184 SemaRef.collectUnexpandedParameterPacks(Pattern, Unexpanded);
2186 // Determine whether the set of unexpanded parameter packs can and should
2189 bool RetainExpansion = false;
2190 Optional<unsigned> OrigNumExpansions
2191 = Expansion.getTypePtr()->getNumExpansions();
2192 Optional<unsigned> NumExpansions = OrigNumExpansions;
2193 if (SemaRef.CheckParameterPacksForExpansion(Expansion.getEllipsisLoc(),
2194 Pattern.getSourceRange(),
2197 Expand, RetainExpansion,
2202 for (unsigned I = 0; I != *NumExpansions; ++I) {
2203 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2204 TypeSourceInfo *NewDI = SemaRef.SubstType(Pattern, TemplateArgs,
2211 SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
2215 ExpandedParameterPackTypesAsWritten.push_back(NewDI);
2216 ExpandedParameterPackTypes.push_back(NewT);
2219 // Note that we have an expanded parameter pack. The "type" of this
2220 // expanded parameter pack is the original expansion type, but callers
2221 // will end up using the expanded parameter pack types for type-checking.
2222 IsExpandedParameterPack = true;
2223 DI = D->getTypeSourceInfo();
2226 // We cannot fully expand the pack expansion now, so substitute into the
2227 // pattern and create a new pack expansion type.
2228 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2229 TypeSourceInfo *NewPattern = SemaRef.SubstType(Pattern, TemplateArgs,
2235 SemaRef.CheckNonTypeTemplateParameterType(NewPattern, D->getLocation());
2236 DI = SemaRef.CheckPackExpansion(NewPattern, Expansion.getEllipsisLoc(),
2244 // Simple case: substitution into a parameter that is not a parameter pack.
2245 DI = SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
2246 D->getLocation(), D->getDeclName());
2250 // Check that this type is acceptable for a non-type template parameter.
2251 T = SemaRef.CheckNonTypeTemplateParameterType(DI, D->getLocation());
2253 T = SemaRef.Context.IntTy;
2258 NonTypeTemplateParmDecl *Param;
2259 if (IsExpandedParameterPack)
2260 Param = NonTypeTemplateParmDecl::Create(
2261 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
2262 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2263 D->getPosition(), D->getIdentifier(), T, DI, ExpandedParameterPackTypes,
2264 ExpandedParameterPackTypesAsWritten);
2266 Param = NonTypeTemplateParmDecl::Create(
2267 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
2268 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2269 D->getPosition(), D->getIdentifier(), T, D->isParameterPack(), DI);
2271 Param->setAccess(AS_public);
2273 Param->setInvalidDecl();
2275 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2276 EnterExpressionEvaluationContext ConstantEvaluated(
2277 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
2278 ExprResult Value = SemaRef.SubstExpr(D->getDefaultArgument(), TemplateArgs);
2279 if (!Value.isInvalid())
2280 Param->setDefaultArgument(Value.get());
2283 // Introduce this template parameter's instantiation into the instantiation
2285 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
2289 static void collectUnexpandedParameterPacks(
2291 TemplateParameterList *Params,
2292 SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) {
2293 for (const auto &P : *Params) {
2294 if (P->isTemplateParameterPack())
2296 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P))
2297 S.collectUnexpandedParameterPacks(NTTP->getTypeSourceInfo()->getTypeLoc(),
2299 if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(P))
2300 collectUnexpandedParameterPacks(S, TTP->getTemplateParameters(),
2306 TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
2307 TemplateTemplateParmDecl *D) {
2308 // Instantiate the template parameter list of the template template parameter.
2309 TemplateParameterList *TempParams = D->getTemplateParameters();
2310 TemplateParameterList *InstParams;
2311 SmallVector<TemplateParameterList*, 8> ExpandedParams;
2313 bool IsExpandedParameterPack = false;
2315 if (D->isExpandedParameterPack()) {
2316 // The template template parameter pack is an already-expanded pack
2317 // expansion of template parameters. Substitute into each of the expanded
2319 ExpandedParams.reserve(D->getNumExpansionTemplateParameters());
2320 for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
2322 LocalInstantiationScope Scope(SemaRef);
2323 TemplateParameterList *Expansion =
2324 SubstTemplateParams(D->getExpansionTemplateParameters(I));
2327 ExpandedParams.push_back(Expansion);
2330 IsExpandedParameterPack = true;
2331 InstParams = TempParams;
2332 } else if (D->isPackExpansion()) {
2333 // The template template parameter pack expands to a pack of template
2334 // template parameters. Determine whether we need to expand this parameter
2335 // pack into separate parameters.
2336 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2337 collectUnexpandedParameterPacks(SemaRef, D->getTemplateParameters(),
2340 // Determine whether the set of unexpanded parameter packs can and should
2343 bool RetainExpansion = false;
2344 Optional<unsigned> NumExpansions;
2345 if (SemaRef.CheckParameterPacksForExpansion(D->getLocation(),
2346 TempParams->getSourceRange(),
2349 Expand, RetainExpansion,
2354 for (unsigned I = 0; I != *NumExpansions; ++I) {
2355 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2356 LocalInstantiationScope Scope(SemaRef);
2357 TemplateParameterList *Expansion = SubstTemplateParams(TempParams);
2360 ExpandedParams.push_back(Expansion);
2363 // Note that we have an expanded parameter pack. The "type" of this
2364 // expanded parameter pack is the original expansion type, but callers
2365 // will end up using the expanded parameter pack types for type-checking.
2366 IsExpandedParameterPack = true;
2367 InstParams = TempParams;
2369 // We cannot fully expand the pack expansion now, so just substitute
2370 // into the pattern.
2371 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2373 LocalInstantiationScope Scope(SemaRef);
2374 InstParams = SubstTemplateParams(TempParams);
2379 // Perform the actual substitution of template parameters within a new,
2380 // local instantiation scope.
2381 LocalInstantiationScope Scope(SemaRef);
2382 InstParams = SubstTemplateParams(TempParams);
2387 // Build the template template parameter.
2388 TemplateTemplateParmDecl *Param;
2389 if (IsExpandedParameterPack)
2390 Param = TemplateTemplateParmDecl::Create(
2391 SemaRef.Context, Owner, D->getLocation(),
2392 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2393 D->getPosition(), D->getIdentifier(), InstParams, ExpandedParams);
2395 Param = TemplateTemplateParmDecl::Create(
2396 SemaRef.Context, Owner, D->getLocation(),
2397 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2398 D->getPosition(), D->isParameterPack(), D->getIdentifier(), InstParams);
2399 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2400 NestedNameSpecifierLoc QualifierLoc =
2401 D->getDefaultArgument().getTemplateQualifierLoc();
2403 SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgs);
2404 TemplateName TName = SemaRef.SubstTemplateName(
2405 QualifierLoc, D->getDefaultArgument().getArgument().getAsTemplate(),
2406 D->getDefaultArgument().getTemplateNameLoc(), TemplateArgs);
2407 if (!TName.isNull())
2408 Param->setDefaultArgument(
2410 TemplateArgumentLoc(TemplateArgument(TName),
2411 D->getDefaultArgument().getTemplateQualifierLoc(),
2412 D->getDefaultArgument().getTemplateNameLoc()));
2414 Param->setAccess(AS_public);
2416 // Introduce this template parameter's instantiation into the instantiation
2418 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
2423 Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
2424 // Using directives are never dependent (and never contain any types or
2425 // expressions), so they require no explicit instantiation work.
2427 UsingDirectiveDecl *Inst
2428 = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
2429 D->getNamespaceKeyLocation(),
2430 D->getQualifierLoc(),
2431 D->getIdentLocation(),
2432 D->getNominatedNamespace(),
2433 D->getCommonAncestor());
2435 // Add the using directive to its declaration context
2436 // only if this is not a function or method.
2437 if (!Owner->isFunctionOrMethod())
2438 Owner->addDecl(Inst);
2443 Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
2445 // The nested name specifier may be dependent, for example
2446 // template <typename T> struct t {
2447 // struct s1 { T f1(); };
2448 // struct s2 : s1 { using s1::f1; };
2450 // template struct t<int>;
2451 // Here, in using s1::f1, s1 refers to t<T>::s1;
2452 // we need to substitute for t<int>::s1.
2453 NestedNameSpecifierLoc QualifierLoc
2454 = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
2459 // For an inheriting constructor declaration, the name of the using
2460 // declaration is the name of a constructor in this class, not in the
2462 DeclarationNameInfo NameInfo = D->getNameInfo();
2463 if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName)
2464 if (auto *RD = dyn_cast<CXXRecordDecl>(SemaRef.CurContext))
2465 NameInfo.setName(SemaRef.Context.DeclarationNames.getCXXConstructorName(
2466 SemaRef.Context.getCanonicalType(SemaRef.Context.getRecordType(RD))));
2468 // We only need to do redeclaration lookups if we're in a class
2469 // scope (in fact, it's not really even possible in non-class
2471 bool CheckRedeclaration = Owner->isRecord();
2473 LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
2474 Sema::ForVisibleRedeclaration);
2476 UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
2483 SS.Adopt(QualifierLoc);
2484 if (CheckRedeclaration) {
2485 Prev.setHideTags(false);
2486 SemaRef.LookupQualifiedName(Prev, Owner);
2488 // Check for invalid redeclarations.
2489 if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLoc(),
2490 D->hasTypename(), SS,
2491 D->getLocation(), Prev))
2492 NewUD->setInvalidDecl();
2496 if (!NewUD->isInvalidDecl() &&
2497 SemaRef.CheckUsingDeclQualifier(D->getUsingLoc(), D->hasTypename(),
2498 SS, NameInfo, D->getLocation()))
2499 NewUD->setInvalidDecl();
2501 SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
2502 NewUD->setAccess(D->getAccess());
2503 Owner->addDecl(NewUD);
2505 // Don't process the shadow decls for an invalid decl.
2506 if (NewUD->isInvalidDecl())
2509 if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName)
2510 SemaRef.CheckInheritingConstructorUsingDecl(NewUD);
2512 bool isFunctionScope = Owner->isFunctionOrMethod();
2514 // Process the shadow decls.
2515 for (auto *Shadow : D->shadows()) {
2516 // FIXME: UsingShadowDecl doesn't preserve its immediate target, so
2517 // reconstruct it in the case where it matters.
2518 NamedDecl *OldTarget = Shadow->getTargetDecl();
2519 if (auto *CUSD = dyn_cast<ConstructorUsingShadowDecl>(Shadow))
2520 if (auto *BaseShadow = CUSD->getNominatedBaseClassShadowDecl())
2521 OldTarget = BaseShadow;
2523 NamedDecl *InstTarget =
2524 cast_or_null<NamedDecl>(SemaRef.FindInstantiatedDecl(
2525 Shadow->getLocation(), OldTarget, TemplateArgs));
2529 UsingShadowDecl *PrevDecl = nullptr;
2530 if (CheckRedeclaration) {
2531 if (SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev, PrevDecl))
2533 } else if (UsingShadowDecl *OldPrev =
2534 getPreviousDeclForInstantiation(Shadow)) {
2535 PrevDecl = cast_or_null<UsingShadowDecl>(SemaRef.FindInstantiatedDecl(
2536 Shadow->getLocation(), OldPrev, TemplateArgs));
2539 UsingShadowDecl *InstShadow =
2540 SemaRef.BuildUsingShadowDecl(/*Scope*/nullptr, NewUD, InstTarget,
2542 SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
2544 if (isFunctionScope)
2545 SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
2551 Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
2552 // Ignore these; we handle them in bulk when processing the UsingDecl.
2556 Decl *TemplateDeclInstantiator::VisitConstructorUsingShadowDecl(
2557 ConstructorUsingShadowDecl *D) {
2558 // Ignore these; we handle them in bulk when processing the UsingDecl.
2562 template <typename T>
2563 Decl *TemplateDeclInstantiator::instantiateUnresolvedUsingDecl(
2564 T *D, bool InstantiatingPackElement) {
2565 // If this is a pack expansion, expand it now.
2566 if (D->isPackExpansion() && !InstantiatingPackElement) {
2567 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2568 SemaRef.collectUnexpandedParameterPacks(D->getQualifierLoc(), Unexpanded);
2569 SemaRef.collectUnexpandedParameterPacks(D->getNameInfo(), Unexpanded);
2571 // Determine whether the set of unexpanded parameter packs can and should
2574 bool RetainExpansion = false;
2575 Optional<unsigned> NumExpansions;
2576 if (SemaRef.CheckParameterPacksForExpansion(
2577 D->getEllipsisLoc(), D->getSourceRange(), Unexpanded, TemplateArgs,
2578 Expand, RetainExpansion, NumExpansions))
2581 // This declaration cannot appear within a function template signature,
2582 // so we can't have a partial argument list for a parameter pack.
2583 assert(!RetainExpansion &&
2584 "should never need to retain an expansion for UsingPackDecl");
2587 // We cannot fully expand the pack expansion now, so substitute into the
2588 // pattern and create a new pack expansion.
2589 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2590 return instantiateUnresolvedUsingDecl(D, true);
2593 // Within a function, we don't have any normal way to check for conflicts
2594 // between shadow declarations from different using declarations in the
2595 // same pack expansion, but this is always ill-formed because all expansions
2596 // must produce (conflicting) enumerators.
2598 // Sadly we can't just reject this in the template definition because it
2599 // could be valid if the pack is empty or has exactly one expansion.
2600 if (D->getDeclContext()->isFunctionOrMethod() && *NumExpansions > 1) {
2601 SemaRef.Diag(D->getEllipsisLoc(),
2602 diag::err_using_decl_redeclaration_expansion);
2606 // Instantiate the slices of this pack and build a UsingPackDecl.
2607 SmallVector<NamedDecl*, 8> Expansions;
2608 for (unsigned I = 0; I != *NumExpansions; ++I) {
2609 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2610 Decl *Slice = instantiateUnresolvedUsingDecl(D, true);
2613 // Note that we can still get unresolved using declarations here, if we
2614 // had arguments for all packs but the pattern also contained other
2615 // template arguments (this only happens during partial substitution, eg
2616 // into the body of a generic lambda in a function template).
2617 Expansions.push_back(cast<NamedDecl>(Slice));
2620 auto *NewD = SemaRef.BuildUsingPackDecl(D, Expansions);
2621 if (isDeclWithinFunction(D))
2622 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewD);
2626 UnresolvedUsingTypenameDecl *TD = dyn_cast<UnresolvedUsingTypenameDecl>(D);
2627 SourceLocation TypenameLoc = TD ? TD->getTypenameLoc() : SourceLocation();
2629 NestedNameSpecifierLoc QualifierLoc
2630 = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
2636 SS.Adopt(QualifierLoc);
2638 DeclarationNameInfo NameInfo
2639 = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
2641 // Produce a pack expansion only if we're not instantiating a particular
2642 // slice of a pack expansion.
2643 bool InstantiatingSlice = D->getEllipsisLoc().isValid() &&
2644 SemaRef.ArgumentPackSubstitutionIndex != -1;
2645 SourceLocation EllipsisLoc =
2646 InstantiatingSlice ? SourceLocation() : D->getEllipsisLoc();
2648 NamedDecl *UD = SemaRef.BuildUsingDeclaration(
2649 /*Scope*/ nullptr, D->getAccess(), D->getUsingLoc(),
2650 /*HasTypename*/ TD, TypenameLoc, SS, NameInfo, EllipsisLoc,
2651 ParsedAttributesView(),
2652 /*IsInstantiation*/ true);
2654 SemaRef.Context.setInstantiatedFromUsingDecl(UD, D);
2659 Decl *TemplateDeclInstantiator::VisitUnresolvedUsingTypenameDecl(
2660 UnresolvedUsingTypenameDecl *D) {
2661 return instantiateUnresolvedUsingDecl(D);
2664 Decl *TemplateDeclInstantiator::VisitUnresolvedUsingValueDecl(
2665 UnresolvedUsingValueDecl *D) {
2666 return instantiateUnresolvedUsingDecl(D);
2669 Decl *TemplateDeclInstantiator::VisitUsingPackDecl(UsingPackDecl *D) {
2670 SmallVector<NamedDecl*, 8> Expansions;
2671 for (auto *UD : D->expansions()) {
2672 if (NamedDecl *NewUD =
2673 SemaRef.FindInstantiatedDecl(D->getLocation(), UD, TemplateArgs))
2674 Expansions.push_back(NewUD);
2679 auto *NewD = SemaRef.BuildUsingPackDecl(D, Expansions);
2680 if (isDeclWithinFunction(D))
2681 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewD);
2685 Decl *TemplateDeclInstantiator::VisitClassScopeFunctionSpecializationDecl(
2686 ClassScopeFunctionSpecializationDecl *Decl) {
2687 CXXMethodDecl *OldFD = Decl->getSpecialization();
2688 CXXMethodDecl *NewFD =
2689 cast_or_null<CXXMethodDecl>(VisitCXXMethodDecl(OldFD, nullptr, true));
2693 LookupResult Previous(SemaRef, NewFD->getNameInfo(), Sema::LookupOrdinaryName,
2694 Sema::ForExternalRedeclaration);
2696 TemplateArgumentListInfo TemplateArgs;
2697 TemplateArgumentListInfo *TemplateArgsPtr = nullptr;
2698 if (Decl->hasExplicitTemplateArgs()) {
2699 TemplateArgs = Decl->templateArgs();
2700 TemplateArgsPtr = &TemplateArgs;
2703 SemaRef.LookupQualifiedName(Previous, SemaRef.CurContext);
2704 if (SemaRef.CheckFunctionTemplateSpecialization(NewFD, TemplateArgsPtr,
2706 NewFD->setInvalidDecl();
2710 // Associate the specialization with the pattern.
2711 FunctionDecl *Specialization = cast<FunctionDecl>(Previous.getFoundDecl());
2712 assert(Specialization && "Class scope Specialization is null");
2713 SemaRef.Context.setClassScopeSpecializationPattern(Specialization, OldFD);
2715 // FIXME: If this is a definition, check for redefinition errors!
2720 Decl *TemplateDeclInstantiator::VisitOMPThreadPrivateDecl(
2721 OMPThreadPrivateDecl *D) {
2722 SmallVector<Expr *, 5> Vars;
2723 for (auto *I : D->varlists()) {
2724 Expr *Var = SemaRef.SubstExpr(I, TemplateArgs).get();
2725 assert(isa<DeclRefExpr>(Var) && "threadprivate arg is not a DeclRefExpr");
2726 Vars.push_back(Var);
2729 OMPThreadPrivateDecl *TD =
2730 SemaRef.CheckOMPThreadPrivateDecl(D->getLocation(), Vars);
2732 TD->setAccess(AS_public);
2738 Decl *TemplateDeclInstantiator::VisitOMPDeclareReductionDecl(
2739 OMPDeclareReductionDecl *D) {
2740 // Instantiate type and check if it is allowed.
2741 QualType SubstReductionType = SemaRef.ActOnOpenMPDeclareReductionType(
2743 ParsedType::make(SemaRef.SubstType(D->getType(), TemplateArgs,
2744 D->getLocation(), DeclarationName())));
2745 if (SubstReductionType.isNull())
2747 bool IsCorrect = !SubstReductionType.isNull();
2748 // Create instantiated copy.
2749 std::pair<QualType, SourceLocation> ReductionTypes[] = {
2750 std::make_pair(SubstReductionType, D->getLocation())};
2751 auto *PrevDeclInScope = D->getPrevDeclInScope();
2752 if (PrevDeclInScope && !PrevDeclInScope->isInvalidDecl()) {
2753 PrevDeclInScope = cast<OMPDeclareReductionDecl>(
2754 SemaRef.CurrentInstantiationScope->findInstantiationOf(PrevDeclInScope)
2757 auto DRD = SemaRef.ActOnOpenMPDeclareReductionDirectiveStart(
2758 /*S=*/nullptr, Owner, D->getDeclName(), ReductionTypes, D->getAccess(),
2760 auto *NewDRD = cast<OMPDeclareReductionDecl>(DRD.get().getSingleDecl());
2761 if (isDeclWithinFunction(NewDRD))
2762 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewDRD);
2763 Expr *SubstCombiner = nullptr;
2764 Expr *SubstInitializer = nullptr;
2765 // Combiners instantiation sequence.
2766 if (D->getCombiner()) {
2767 SemaRef.ActOnOpenMPDeclareReductionCombinerStart(
2768 /*S=*/nullptr, NewDRD);
2769 const char *Names[] = {"omp_in", "omp_out"};
2770 for (auto &Name : Names) {
2771 DeclarationName DN(&SemaRef.Context.Idents.get(Name));
2772 auto OldLookup = D->lookup(DN);
2773 auto Lookup = NewDRD->lookup(DN);
2774 if (!OldLookup.empty() && !Lookup.empty()) {
2775 assert(Lookup.size() == 1 && OldLookup.size() == 1);
2776 SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldLookup.front(),
2780 SubstCombiner = SemaRef.SubstExpr(D->getCombiner(), TemplateArgs).get();
2781 SemaRef.ActOnOpenMPDeclareReductionCombinerEnd(NewDRD, SubstCombiner);
2782 // Initializers instantiation sequence.
2783 if (D->getInitializer()) {
2784 VarDecl *OmpPrivParm =
2785 SemaRef.ActOnOpenMPDeclareReductionInitializerStart(
2786 /*S=*/nullptr, NewDRD);
2787 const char *Names[] = {"omp_orig", "omp_priv"};
2788 for (auto &Name : Names) {
2789 DeclarationName DN(&SemaRef.Context.Idents.get(Name));
2790 auto OldLookup = D->lookup(DN);
2791 auto Lookup = NewDRD->lookup(DN);
2792 if (!OldLookup.empty() && !Lookup.empty()) {
2793 assert(Lookup.size() == 1 && OldLookup.size() == 1);
2794 auto *OldVD = cast<VarDecl>(OldLookup.front());
2795 auto *NewVD = cast<VarDecl>(Lookup.front());
2796 SemaRef.InstantiateVariableInitializer(NewVD, OldVD, TemplateArgs);
2797 SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldVD, NewVD);
2800 if (D->getInitializerKind() == OMPDeclareReductionDecl::CallInit) {
2802 SemaRef.SubstExpr(D->getInitializer(), TemplateArgs).get();
2804 IsCorrect = IsCorrect && OmpPrivParm->hasInit();
2806 SemaRef.ActOnOpenMPDeclareReductionInitializerEnd(
2807 NewDRD, SubstInitializer, OmpPrivParm);
2810 IsCorrect && SubstCombiner &&
2811 (!D->getInitializer() ||
2812 (D->getInitializerKind() == OMPDeclareReductionDecl::CallInit &&
2813 SubstInitializer) ||
2814 (D->getInitializerKind() != OMPDeclareReductionDecl::CallInit &&
2815 !SubstInitializer && !SubstInitializer));
2819 (void)SemaRef.ActOnOpenMPDeclareReductionDirectiveEnd(/*S=*/nullptr, DRD,
2825 Decl *TemplateDeclInstantiator::VisitOMPCapturedExprDecl(
2826 OMPCapturedExprDecl * /*D*/) {
2827 llvm_unreachable("Should not be met in templates");
2830 Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D) {
2831 return VisitFunctionDecl(D, nullptr);
2835 TemplateDeclInstantiator::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
2836 Decl *Inst = VisitFunctionDecl(D, nullptr);
2837 if (Inst && !D->getDescribedFunctionTemplate())
2838 Owner->addDecl(Inst);
2842 Decl *TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D) {
2843 return VisitCXXMethodDecl(D, nullptr);
2846 Decl *TemplateDeclInstantiator::VisitRecordDecl(RecordDecl *D) {
2847 llvm_unreachable("There are only CXXRecordDecls in C++");
2851 TemplateDeclInstantiator::VisitClassTemplateSpecializationDecl(
2852 ClassTemplateSpecializationDecl *D) {
2853 // As a MS extension, we permit class-scope explicit specialization
2854 // of member class templates.
2855 ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
2856 assert(ClassTemplate->getDeclContext()->isRecord() &&
2857 D->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
2858 "can only instantiate an explicit specialization "
2859 "for a member class template");
2861 // Lookup the already-instantiated declaration in the instantiation
2862 // of the class template. FIXME: Diagnose or assert if this fails?
2863 DeclContext::lookup_result Found
2864 = Owner->lookup(ClassTemplate->getDeclName());
2867 ClassTemplateDecl *InstClassTemplate
2868 = dyn_cast<ClassTemplateDecl>(Found.front());
2869 if (!InstClassTemplate)
2872 // Substitute into the template arguments of the class template explicit
2874 TemplateSpecializationTypeLoc Loc = D->getTypeAsWritten()->getTypeLoc().
2875 castAs<TemplateSpecializationTypeLoc>();
2876 TemplateArgumentListInfo InstTemplateArgs(Loc.getLAngleLoc(),
2877 Loc.getRAngleLoc());
2878 SmallVector<TemplateArgumentLoc, 4> ArgLocs;
2879 for (unsigned I = 0; I != Loc.getNumArgs(); ++I)
2880 ArgLocs.push_back(Loc.getArgLoc(I));
2881 if (SemaRef.Subst(ArgLocs.data(), ArgLocs.size(),
2882 InstTemplateArgs, TemplateArgs))
2885 // Check that the template argument list is well-formed for this
2887 SmallVector<TemplateArgument, 4> Converted;
2888 if (SemaRef.CheckTemplateArgumentList(InstClassTemplate,
2895 // Figure out where to insert this class template explicit specialization
2896 // in the member template's set of class template explicit specializations.
2897 void *InsertPos = nullptr;
2898 ClassTemplateSpecializationDecl *PrevDecl =
2899 InstClassTemplate->findSpecialization(Converted, InsertPos);
2901 // Check whether we've already seen a conflicting instantiation of this
2902 // declaration (for instance, if there was a prior implicit instantiation).
2905 SemaRef.CheckSpecializationInstantiationRedecl(D->getLocation(),
2906 D->getSpecializationKind(),
2908 PrevDecl->getSpecializationKind(),
2909 PrevDecl->getPointOfInstantiation(),
2913 // If PrevDecl was a definition and D is also a definition, diagnose.
2914 // This happens in cases like:
2916 // template<typename T, typename U>
2918 // template<typename X> struct Inner;
2919 // template<> struct Inner<T> {};
2920 // template<> struct Inner<U> {};
2923 // Outer<int, int> outer; // error: the explicit specializations of Inner
2924 // // have the same signature.
2925 if (PrevDecl && PrevDecl->getDefinition() &&
2926 D->isThisDeclarationADefinition()) {
2927 SemaRef.Diag(D->getLocation(), diag::err_redefinition) << PrevDecl;
2928 SemaRef.Diag(PrevDecl->getDefinition()->getLocation(),
2929 diag::note_previous_definition);
2933 // Create the class template partial specialization declaration.
2934 ClassTemplateSpecializationDecl *InstD
2935 = ClassTemplateSpecializationDecl::Create(SemaRef.Context,
2944 // Add this partial specialization to the set of class template partial
2947 InstClassTemplate->AddSpecialization(InstD, InsertPos);
2949 // Substitute the nested name specifier, if any.
2950 if (SubstQualifier(D, InstD))
2953 // Build the canonical type that describes the converted template
2954 // arguments of the class template explicit specialization.
2955 QualType CanonType = SemaRef.Context.getTemplateSpecializationType(
2956 TemplateName(InstClassTemplate), Converted,
2957 SemaRef.Context.getRecordType(InstD));
2959 // Build the fully-sugared type for this class template
2960 // specialization as the user wrote in the specialization
2961 // itself. This means that we'll pretty-print the type retrieved
2962 // from the specialization's declaration the way that the user
2963 // actually wrote the specialization, rather than formatting the
2964 // name based on the "canonical" representation used to store the
2965 // template arguments in the specialization.
2966 TypeSourceInfo *WrittenTy = SemaRef.Context.getTemplateSpecializationTypeInfo(
2967 TemplateName(InstClassTemplate), D->getLocation(), InstTemplateArgs,
2970 InstD->setAccess(D->getAccess());
2971 InstD->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
2972 InstD->setSpecializationKind(D->getSpecializationKind());
2973 InstD->setTypeAsWritten(WrittenTy);
2974 InstD->setExternLoc(D->getExternLoc());
2975 InstD->setTemplateKeywordLoc(D->getTemplateKeywordLoc());
2977 Owner->addDecl(InstD);
2979 // Instantiate the members of the class-scope explicit specialization eagerly.
2980 // We don't have support for lazy instantiation of an explicit specialization
2981 // yet, and MSVC eagerly instantiates in this case.
2982 if (D->isThisDeclarationADefinition() &&
2983 SemaRef.InstantiateClass(D->getLocation(), InstD, D, TemplateArgs,
2984 TSK_ImplicitInstantiation,
2991 Decl *TemplateDeclInstantiator::VisitVarTemplateSpecializationDecl(
2992 VarTemplateSpecializationDecl *D) {
2994 TemplateArgumentListInfo VarTemplateArgsInfo;
2995 VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
2996 assert(VarTemplate &&
2997 "A template specialization without specialized template?");
2999 // Substitute the current template arguments.
3000 const TemplateArgumentListInfo &TemplateArgsInfo = D->getTemplateArgsInfo();
3001 VarTemplateArgsInfo.setLAngleLoc(TemplateArgsInfo.getLAngleLoc());
3002 VarTemplateArgsInfo.setRAngleLoc(TemplateArgsInfo.getRAngleLoc());
3004 if (SemaRef.Subst(TemplateArgsInfo.getArgumentArray(),
3005 TemplateArgsInfo.size(), VarTemplateArgsInfo, TemplateArgs))
3008 // Check that the template argument list is well-formed for this template.
3009 SmallVector<TemplateArgument, 4> Converted;
3010 if (SemaRef.CheckTemplateArgumentList(
3011 VarTemplate, VarTemplate->getLocStart(),
3012 const_cast<TemplateArgumentListInfo &>(VarTemplateArgsInfo), false,
3016 // Find the variable template specialization declaration that
3017 // corresponds to these arguments.
3018 void *InsertPos = nullptr;
3019 if (VarTemplateSpecializationDecl *VarSpec = VarTemplate->findSpecialization(
3020 Converted, InsertPos))
3021 // If we already have a variable template specialization, return it.
3024 return VisitVarTemplateSpecializationDecl(VarTemplate, D, InsertPos,
3025 VarTemplateArgsInfo, Converted);
3028 Decl *TemplateDeclInstantiator::VisitVarTemplateSpecializationDecl(
3029 VarTemplateDecl *VarTemplate, VarDecl *D, void *InsertPos,
3030 const TemplateArgumentListInfo &TemplateArgsInfo,
3031 ArrayRef<TemplateArgument> Converted) {
3033 // Do substitution on the type of the declaration
3034 TypeSourceInfo *DI =
3035 SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
3036 D->getTypeSpecStartLoc(), D->getDeclName());
3040 if (DI->getType()->isFunctionType()) {
3041 SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
3042 << D->isStaticDataMember() << DI->getType();
3046 // Build the instantiated declaration
3047 VarTemplateSpecializationDecl *Var = VarTemplateSpecializationDecl::Create(
3048 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
3049 VarTemplate, DI->getType(), DI, D->getStorageClass(), Converted);
3050 Var->setTemplateArgsInfo(TemplateArgsInfo);
3052 VarTemplate->AddSpecialization(Var, InsertPos);
3054 // Substitute the nested name specifier, if any.
3055 if (SubstQualifier(D, Var))
3058 SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs,
3059 Owner, StartingScope);
3064 Decl *TemplateDeclInstantiator::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
3065 llvm_unreachable("@defs is not supported in Objective-C++");
3068 Decl *TemplateDeclInstantiator::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
3069 // FIXME: We need to be able to instantiate FriendTemplateDecls.
3070 unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
3071 DiagnosticsEngine::Error,
3072 "cannot instantiate %0 yet");
3073 SemaRef.Diag(D->getLocation(), DiagID)
3074 << D->getDeclKindName();
3079 Decl *TemplateDeclInstantiator::VisitDecl(Decl *D) {
3080 llvm_unreachable("Unexpected decl");
3083 Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
3084 const MultiLevelTemplateArgumentList &TemplateArgs) {
3085 TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
3086 if (D->isInvalidDecl())
3089 return Instantiator.Visit(D);
3092 /// Instantiates a nested template parameter list in the current
3093 /// instantiation context.
3095 /// \param L The parameter list to instantiate
3097 /// \returns NULL if there was an error
3098 TemplateParameterList *
3099 TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
3100 // Get errors for all the parameters before bailing out.
3101 bool Invalid = false;
3103 unsigned N = L->size();
3104 typedef SmallVector<NamedDecl *, 8> ParamVector;
3107 for (auto &P : *L) {
3108 NamedDecl *D = cast_or_null<NamedDecl>(Visit(P));
3109 Params.push_back(D);
3110 Invalid = Invalid || !D || D->isInvalidDecl();
3113 // Clean up if we had an error.
3117 // Note: we substitute into associated constraints later
3118 Expr *const UninstantiatedRequiresClause = L->getRequiresClause();
3120 TemplateParameterList *InstL
3121 = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
3122 L->getLAngleLoc(), Params,
3124 UninstantiatedRequiresClause);
3128 TemplateParameterList *
3129 Sema::SubstTemplateParams(TemplateParameterList *Params, DeclContext *Owner,
3130 const MultiLevelTemplateArgumentList &TemplateArgs) {
3131 TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
3132 return Instantiator.SubstTemplateParams(Params);
3135 /// Instantiate the declaration of a class template partial
3138 /// \param ClassTemplate the (instantiated) class template that is partially
3139 // specialized by the instantiation of \p PartialSpec.
3141 /// \param PartialSpec the (uninstantiated) class template partial
3142 /// specialization that we are instantiating.
3144 /// \returns The instantiated partial specialization, if successful; otherwise,
3145 /// NULL to indicate an error.
3146 ClassTemplatePartialSpecializationDecl *
3147 TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
3148 ClassTemplateDecl *ClassTemplate,
3149 ClassTemplatePartialSpecializationDecl *PartialSpec) {
3150 // Create a local instantiation scope for this class template partial
3151 // specialization, which will contain the instantiations of the template
3153 LocalInstantiationScope Scope(SemaRef);
3155 // Substitute into the template parameters of the class template partial
3157 TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
3158 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
3162 // Substitute into the template arguments of the class template partial
3164 const ASTTemplateArgumentListInfo *TemplArgInfo
3165 = PartialSpec->getTemplateArgsAsWritten();
3166 TemplateArgumentListInfo InstTemplateArgs(TemplArgInfo->LAngleLoc,
3167 TemplArgInfo->RAngleLoc);
3168 if (SemaRef.Subst(TemplArgInfo->getTemplateArgs(),
3169 TemplArgInfo->NumTemplateArgs,
3170 InstTemplateArgs, TemplateArgs))
3173 // Check that the template argument list is well-formed for this
3175 SmallVector<TemplateArgument, 4> Converted;
3176 if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
3177 PartialSpec->getLocation(),
3183 // Check these arguments are valid for a template partial specialization.
3184 if (SemaRef.CheckTemplatePartialSpecializationArgs(
3185 PartialSpec->getLocation(), ClassTemplate, InstTemplateArgs.size(),
3189 // Figure out where to insert this class template partial specialization
3190 // in the member template's set of class template partial specializations.
3191 void *InsertPos = nullptr;
3192 ClassTemplateSpecializationDecl *PrevDecl
3193 = ClassTemplate->findPartialSpecialization(Converted, InsertPos);
3195 // Build the canonical type that describes the converted template
3196 // arguments of the class template partial specialization.
3198 = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
3201 // Build the fully-sugared type for this class template
3202 // specialization as the user wrote in the specialization
3203 // itself. This means that we'll pretty-print the type retrieved
3204 // from the specialization's declaration the way that the user
3205 // actually wrote the specialization, rather than formatting the
3206 // name based on the "canonical" representation used to store the
3207 // template arguments in the specialization.
3208 TypeSourceInfo *WrittenTy
3209 = SemaRef.Context.getTemplateSpecializationTypeInfo(
3210 TemplateName(ClassTemplate),
3211 PartialSpec->getLocation(),
3216 // We've already seen a partial specialization with the same template
3217 // parameters and template arguments. This can happen, for example, when
3218 // substituting the outer template arguments ends up causing two
3219 // class template partial specializations of a member class template
3220 // to have identical forms, e.g.,
3222 // template<typename T, typename U>
3224 // template<typename X, typename Y> struct Inner;
3225 // template<typename Y> struct Inner<T, Y>;
3226 // template<typename Y> struct Inner<U, Y>;
3229 // Outer<int, int> outer; // error: the partial specializations of Inner
3230 // // have the same signature.
3231 SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
3232 << WrittenTy->getType();
3233 SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
3234 << SemaRef.Context.getTypeDeclType(PrevDecl);
3239 // Create the class template partial specialization declaration.
3240 ClassTemplatePartialSpecializationDecl *InstPartialSpec
3241 = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
3242 PartialSpec->getTagKind(),
3244 PartialSpec->getLocStart(),
3245 PartialSpec->getLocation(),
3252 // Substitute the nested name specifier, if any.
3253 if (SubstQualifier(PartialSpec, InstPartialSpec))
3256 InstPartialSpec->setInstantiatedFromMember(PartialSpec);
3257 InstPartialSpec->setTypeAsWritten(WrittenTy);
3259 // Check the completed partial specialization.
3260 SemaRef.CheckTemplatePartialSpecialization(InstPartialSpec);
3262 // Add this partial specialization to the set of class template partial
3264 ClassTemplate->AddPartialSpecialization(InstPartialSpec,
3265 /*InsertPos=*/nullptr);
3266 return InstPartialSpec;
3269 /// Instantiate the declaration of a variable template partial
3272 /// \param VarTemplate the (instantiated) variable template that is partially
3273 /// specialized by the instantiation of \p PartialSpec.
3275 /// \param PartialSpec the (uninstantiated) variable template partial
3276 /// specialization that we are instantiating.
3278 /// \returns The instantiated partial specialization, if successful; otherwise,
3279 /// NULL to indicate an error.
3280 VarTemplatePartialSpecializationDecl *
3281 TemplateDeclInstantiator::InstantiateVarTemplatePartialSpecialization(
3282 VarTemplateDecl *VarTemplate,
3283 VarTemplatePartialSpecializationDecl *PartialSpec) {
3284 // Create a local instantiation scope for this variable template partial
3285 // specialization, which will contain the instantiations of the template
3287 LocalInstantiationScope Scope(SemaRef);
3289 // Substitute into the template parameters of the variable template partial
3291 TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
3292 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
3296 // Substitute into the template arguments of the variable template partial
3298 const ASTTemplateArgumentListInfo *TemplArgInfo
3299 = PartialSpec->getTemplateArgsAsWritten();
3300 TemplateArgumentListInfo InstTemplateArgs(TemplArgInfo->LAngleLoc,
3301 TemplArgInfo->RAngleLoc);
3302 if (SemaRef.Subst(TemplArgInfo->getTemplateArgs(),
3303 TemplArgInfo->NumTemplateArgs,
3304 InstTemplateArgs, TemplateArgs))
3307 // Check that the template argument list is well-formed for this
3309 SmallVector<TemplateArgument, 4> Converted;
3310 if (SemaRef.CheckTemplateArgumentList(VarTemplate, PartialSpec->getLocation(),
3311 InstTemplateArgs, false, Converted))
3314 // Check these arguments are valid for a template partial specialization.
3315 if (SemaRef.CheckTemplatePartialSpecializationArgs(
3316 PartialSpec->getLocation(), VarTemplate, InstTemplateArgs.size(),
3320 // Figure out where to insert this variable template partial specialization
3321 // in the member template's set of variable template partial specializations.
3322 void *InsertPos = nullptr;
3323 VarTemplateSpecializationDecl *PrevDecl =
3324 VarTemplate->findPartialSpecialization(Converted, InsertPos);
3326 // Build the canonical type that describes the converted template
3327 // arguments of the variable template partial specialization.
3328 QualType CanonType = SemaRef.Context.getTemplateSpecializationType(
3329 TemplateName(VarTemplate), Converted);
3331 // Build the fully-sugared type for this variable template
3332 // specialization as the user wrote in the specialization
3333 // itself. This means that we'll pretty-print the type retrieved
3334 // from the specialization's declaration the way that the user
3335 // actually wrote the specialization, rather than formatting the
3336 // name based on the "canonical" representation used to store the
3337 // template arguments in the specialization.
3338 TypeSourceInfo *WrittenTy = SemaRef.Context.getTemplateSpecializationTypeInfo(
3339 TemplateName(VarTemplate), PartialSpec->getLocation(), InstTemplateArgs,
3343 // We've already seen a partial specialization with the same template
3344 // parameters and template arguments. This can happen, for example, when
3345 // substituting the outer template arguments ends up causing two
3346 // variable template partial specializations of a member variable template
3347 // to have identical forms, e.g.,
3349 // template<typename T, typename U>
3351 // template<typename X, typename Y> pair<X,Y> p;
3352 // template<typename Y> pair<T, Y> p;
3353 // template<typename Y> pair<U, Y> p;
3356 // Outer<int, int> outer; // error: the partial specializations of Inner
3357 // // have the same signature.
3358 SemaRef.Diag(PartialSpec->getLocation(),
3359 diag::err_var_partial_spec_redeclared)
3360 << WrittenTy->getType();
3361 SemaRef.Diag(PrevDecl->getLocation(),
3362 diag::note_var_prev_partial_spec_here);
3366 // Do substitution on the type of the declaration
3367 TypeSourceInfo *DI = SemaRef.SubstType(
3368 PartialSpec->getTypeSourceInfo(), TemplateArgs,
3369 PartialSpec->getTypeSpecStartLoc(), PartialSpec->getDeclName());
3373 if (DI->getType()->isFunctionType()) {
3374 SemaRef.Diag(PartialSpec->getLocation(),
3375 diag::err_variable_instantiates_to_function)
3376 << PartialSpec->isStaticDataMember() << DI->getType();
3380 // Create the variable template partial specialization declaration.
3381 VarTemplatePartialSpecializationDecl *InstPartialSpec =
3382 VarTemplatePartialSpecializationDecl::Create(
3383 SemaRef.Context, Owner, PartialSpec->getInnerLocStart(),
3384 PartialSpec->getLocation(), InstParams, VarTemplate, DI->getType(),
3385 DI, PartialSpec->getStorageClass(), Converted, InstTemplateArgs);
3387 // Substitute the nested name specifier, if any.
3388 if (SubstQualifier(PartialSpec, InstPartialSpec))
3391 InstPartialSpec->setInstantiatedFromMember(PartialSpec);
3392 InstPartialSpec->setTypeAsWritten(WrittenTy);
3394 // Check the completed partial specialization.
3395 SemaRef.CheckTemplatePartialSpecialization(InstPartialSpec);
3397 // Add this partial specialization to the set of variable template partial
3398 // specializations. The instantiation of the initializer is not necessary.
3399 VarTemplate->AddPartialSpecialization(InstPartialSpec, /*InsertPos=*/nullptr);
3401 SemaRef.BuildVariableInstantiation(InstPartialSpec, PartialSpec, TemplateArgs,
3402 LateAttrs, Owner, StartingScope);
3404 return InstPartialSpec;
3408 TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
3409 SmallVectorImpl<ParmVarDecl *> &Params) {
3410 TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
3411 assert(OldTInfo && "substituting function without type source info");
3412 assert(Params.empty() && "parameter vector is non-empty at start");
3414 CXXRecordDecl *ThisContext = nullptr;
3415 unsigned ThisTypeQuals = 0;
3416 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
3417 ThisContext = cast<CXXRecordDecl>(Owner);
3418 ThisTypeQuals = Method->getTypeQualifiers();
3421 TypeSourceInfo *NewTInfo
3422 = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
3423 D->getTypeSpecStartLoc(),
3425 ThisContext, ThisTypeQuals);
3429 TypeLoc OldTL = OldTInfo->getTypeLoc().IgnoreParens();
3430 if (FunctionProtoTypeLoc OldProtoLoc = OldTL.getAs<FunctionProtoTypeLoc>()) {
3431 if (NewTInfo != OldTInfo) {
3432 // Get parameters from the new type info.
3433 TypeLoc NewTL = NewTInfo->getTypeLoc().IgnoreParens();
3434 FunctionProtoTypeLoc NewProtoLoc = NewTL.castAs<FunctionProtoTypeLoc>();
3435 unsigned NewIdx = 0;
3436 for (unsigned OldIdx = 0, NumOldParams = OldProtoLoc.getNumParams();
3437 OldIdx != NumOldParams; ++OldIdx) {
3438 ParmVarDecl *OldParam = OldProtoLoc.getParam(OldIdx);
3439 LocalInstantiationScope *Scope = SemaRef.CurrentInstantiationScope;
3441 Optional<unsigned> NumArgumentsInExpansion;
3442 if (OldParam->isParameterPack())
3443 NumArgumentsInExpansion =
3444 SemaRef.getNumArgumentsInExpansion(OldParam->getType(),
3446 if (!NumArgumentsInExpansion) {
3447 // Simple case: normal parameter, or a parameter pack that's
3448 // instantiated to a (still-dependent) parameter pack.
3449 ParmVarDecl *NewParam = NewProtoLoc.getParam(NewIdx++);
3450 Params.push_back(NewParam);
3451 Scope->InstantiatedLocal(OldParam, NewParam);
3453 // Parameter pack expansion: make the instantiation an argument pack.
3454 Scope->MakeInstantiatedLocalArgPack(OldParam);
3455 for (unsigned I = 0; I != *NumArgumentsInExpansion; ++I) {
3456 ParmVarDecl *NewParam = NewProtoLoc.getParam(NewIdx++);
3457 Params.push_back(NewParam);
3458 Scope->InstantiatedLocalPackArg(OldParam, NewParam);
3463 // The function type itself was not dependent and therefore no
3464 // substitution occurred. However, we still need to instantiate
3465 // the function parameters themselves.
3466 const FunctionProtoType *OldProto =
3467 cast<FunctionProtoType>(OldProtoLoc.getType());
3468 for (unsigned i = 0, i_end = OldProtoLoc.getNumParams(); i != i_end;
3470 ParmVarDecl *OldParam = OldProtoLoc.getParam(i);
3472 Params.push_back(SemaRef.BuildParmVarDeclForTypedef(
3473 D, D->getLocation(), OldProto->getParamType(i)));
3478 cast_or_null<ParmVarDecl>(VisitParmVarDecl(OldParam));
3481 Params.push_back(Parm);
3485 // If the type of this function, after ignoring parentheses, is not
3486 // *directly* a function type, then we're instantiating a function that
3487 // was declared via a typedef or with attributes, e.g.,
3489 // typedef int functype(int, int);
3491 // int __cdecl meth(int, int);
3493 // In this case, we'll just go instantiate the ParmVarDecls that we
3494 // synthesized in the method declaration.
3495 SmallVector<QualType, 4> ParamTypes;
3496 Sema::ExtParameterInfoBuilder ExtParamInfos;
3497 if (SemaRef.SubstParmTypes(D->getLocation(), D->parameters(), nullptr,
3498 TemplateArgs, ParamTypes, &Params,
3506 /// Introduce the instantiated function parameters into the local
3507 /// instantiation scope, and set the parameter names to those used
3508 /// in the template.
3509 static bool addInstantiatedParametersToScope(Sema &S, FunctionDecl *Function,
3510 const FunctionDecl *PatternDecl,
3511 LocalInstantiationScope &Scope,
3512 const MultiLevelTemplateArgumentList &TemplateArgs) {
3513 unsigned FParamIdx = 0;
3514 for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
3515 const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
3516 if (!PatternParam->isParameterPack()) {
3517 // Simple case: not a parameter pack.
3518 assert(FParamIdx < Function->getNumParams());
3519 ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
3520 FunctionParam->setDeclName(PatternParam->getDeclName());
3521 // If the parameter's type is not dependent, update it to match the type
3522 // in the pattern. They can differ in top-level cv-qualifiers, and we want
3523 // the pattern's type here. If the type is dependent, they can't differ,
3524 // per core issue 1668. Substitute into the type from the pattern, in case
3525 // it's instantiation-dependent.
3526 // FIXME: Updating the type to work around this is at best fragile.
3527 if (!PatternDecl->getType()->isDependentType()) {
3528 QualType T = S.SubstType(PatternParam->getType(), TemplateArgs,
3529 FunctionParam->getLocation(),
3530 FunctionParam->getDeclName());
3533 FunctionParam->setType(T);
3536 Scope.InstantiatedLocal(PatternParam, FunctionParam);
3541 // Expand the parameter pack.
3542 Scope.MakeInstantiatedLocalArgPack(PatternParam);
3543 Optional<unsigned> NumArgumentsInExpansion
3544 = S.getNumArgumentsInExpansion(PatternParam->getType(), TemplateArgs);
3545 assert(NumArgumentsInExpansion &&
3546 "should only be called when all template arguments are known");
3547 QualType PatternType =
3548 PatternParam->getType()->castAs<PackExpansionType>()->getPattern();
3549 for (unsigned Arg = 0; Arg < *NumArgumentsInExpansion; ++Arg) {
3550 ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
3551 FunctionParam->setDeclName(PatternParam->getDeclName());
3552 if (!PatternDecl->getType()->isDependentType()) {
3553 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, Arg);
3554 QualType T = S.SubstType(PatternType, TemplateArgs,
3555 FunctionParam->getLocation(),
3556 FunctionParam->getDeclName());
3559 FunctionParam->setType(T);
3562 Scope.InstantiatedLocalPackArg(PatternParam, FunctionParam);
3570 void Sema::InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
3571 FunctionDecl *Decl) {
3572 const FunctionProtoType *Proto = Decl->getType()->castAs<FunctionProtoType>();
3573 if (Proto->getExceptionSpecType() != EST_Uninstantiated)
3576 InstantiatingTemplate Inst(*this, PointOfInstantiation, Decl,
3577 InstantiatingTemplate::ExceptionSpecification());
3578 if (Inst.isInvalid()) {
3579 // We hit the instantiation depth limit. Clear the exception specification
3580 // so that our callers don't have to cope with EST_Uninstantiated.
3581 UpdateExceptionSpec(Decl, EST_None);
3584 if (Inst.isAlreadyInstantiating()) {
3585 // This exception specification indirectly depends on itself. Reject.
3586 // FIXME: Corresponding rule in the standard?
3587 Diag(PointOfInstantiation, diag::err_exception_spec_cycle) << Decl;
3588 UpdateExceptionSpec(Decl, EST_None);
3592 // Enter the scope of this instantiation. We don't use
3593 // PushDeclContext because we don't have a scope.
3594 Sema::ContextRAII savedContext(*this, Decl);
3595 LocalInstantiationScope Scope(*this);
3597 MultiLevelTemplateArgumentList TemplateArgs =
3598 getTemplateInstantiationArgs(Decl, nullptr, /*RelativeToPrimary*/true);
3600 FunctionDecl *Template = Proto->getExceptionSpecTemplate();
3601 if (addInstantiatedParametersToScope(*this, Decl, Template, Scope,
3603 UpdateExceptionSpec(Decl, EST_None);
3607 SubstExceptionSpec(Decl, Template->getType()->castAs<FunctionProtoType>(),
3611 /// Initializes the common fields of an instantiation function
3612 /// declaration (New) from the corresponding fields of its template (Tmpl).
3614 /// \returns true if there was an error
3616 TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
3617 FunctionDecl *Tmpl) {
3618 if (Tmpl->isDeleted())
3619 New->setDeletedAsWritten();
3621 New->setImplicit(Tmpl->isImplicit());
3623 // Forward the mangling number from the template to the instantiated decl.
3624 SemaRef.Context.setManglingNumber(New,
3625 SemaRef.Context.getManglingNumber(Tmpl));
3627 // If we are performing substituting explicitly-specified template arguments
3628 // or deduced template arguments into a function template and we reach this
3629 // point, we are now past the point where SFINAE applies and have committed
3630 // to keeping the new function template specialization. We therefore
3631 // convert the active template instantiation for the function template
3632 // into a template instantiation for this specific function template
3633 // specialization, which is not a SFINAE context, so that we diagnose any
3634 // further errors in the declaration itself.
3635 typedef Sema::CodeSynthesisContext ActiveInstType;
3636 ActiveInstType &ActiveInst = SemaRef.CodeSynthesisContexts.back();
3637 if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
3638 ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
3639 if (FunctionTemplateDecl *FunTmpl
3640 = dyn_cast<FunctionTemplateDecl>(ActiveInst.Entity)) {
3641 assert(FunTmpl->getTemplatedDecl() == Tmpl &&
3642 "Deduction from the wrong function template?");
3644 atTemplateEnd(SemaRef.TemplateInstCallbacks, SemaRef, ActiveInst);
3645 ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
3646 ActiveInst.Entity = New;
3647 atTemplateBegin(SemaRef.TemplateInstCallbacks, SemaRef, ActiveInst);
3651 const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
3652 assert(Proto && "Function template without prototype?");
3654 if (Proto->hasExceptionSpec() || Proto->getNoReturnAttr()) {
3655 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
3657 // DR1330: In C++11, defer instantiation of a non-trivial
3658 // exception specification.
3659 // DR1484: Local classes and their members are instantiated along with the
3660 // containing function.
3661 if (SemaRef.getLangOpts().CPlusPlus11 &&
3662 EPI.ExceptionSpec.Type != EST_None &&
3663 EPI.ExceptionSpec.Type != EST_DynamicNone &&
3664 EPI.ExceptionSpec.Type != EST_BasicNoexcept &&
3665 !Tmpl->isLexicallyWithinFunctionOrMethod()) {
3666 FunctionDecl *ExceptionSpecTemplate = Tmpl;
3667 if (EPI.ExceptionSpec.Type == EST_Uninstantiated)
3668 ExceptionSpecTemplate = EPI.ExceptionSpec.SourceTemplate;
3669 ExceptionSpecificationType NewEST = EST_Uninstantiated;
3670 if (EPI.ExceptionSpec.Type == EST_Unevaluated)
3671 NewEST = EST_Unevaluated;
3673 // Mark the function has having an uninstantiated exception specification.
3674 const FunctionProtoType *NewProto
3675 = New->getType()->getAs<FunctionProtoType>();
3676 assert(NewProto && "Template instantiation without function prototype?");
3677 EPI = NewProto->getExtProtoInfo();
3678 EPI.ExceptionSpec.Type = NewEST;
3679 EPI.ExceptionSpec.SourceDecl = New;
3680 EPI.ExceptionSpec.SourceTemplate = ExceptionSpecTemplate;
3681 New->setType(SemaRef.Context.getFunctionType(
3682 NewProto->getReturnType(), NewProto->getParamTypes(), EPI));
3684 Sema::ContextRAII SwitchContext(SemaRef, New);
3685 SemaRef.SubstExceptionSpec(New, Proto, TemplateArgs);
3689 // Get the definition. Leaves the variable unchanged if undefined.
3690 const FunctionDecl *Definition = Tmpl;
3691 Tmpl->isDefined(Definition);
3693 SemaRef.InstantiateAttrs(TemplateArgs, Definition, New,
3694 LateAttrs, StartingScope);
3699 /// Initializes common fields of an instantiated method
3700 /// declaration (New) from the corresponding fields of its template
3703 /// \returns true if there was an error
3705 TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
3706 CXXMethodDecl *Tmpl) {
3707 if (InitFunctionInstantiation(New, Tmpl))
3710 New->setAccess(Tmpl->getAccess());
3711 if (Tmpl->isVirtualAsWritten())
3712 New->setVirtualAsWritten(true);
3714 // FIXME: New needs a pointer to Tmpl
3718 /// Instantiate (or find existing instantiation of) a function template with a
3719 /// given set of template arguments.
3721 /// Usually this should not be used, and template argument deduction should be
3722 /// used in its place.
3724 Sema::InstantiateFunctionDeclaration(FunctionTemplateDecl *FTD,
3725 const TemplateArgumentList *Args,
3726 SourceLocation Loc) {
3727 FunctionDecl *FD = FTD->getTemplatedDecl();
3729 sema::TemplateDeductionInfo Info(Loc);
3730 InstantiatingTemplate Inst(
3731 *this, Loc, FTD, Args->asArray(),
3732 CodeSynthesisContext::ExplicitTemplateArgumentSubstitution, Info);
3733 if (Inst.isInvalid())
3736 ContextRAII SavedContext(*this, FD);
3737 MultiLevelTemplateArgumentList MArgs(*Args);
3739 return cast_or_null<FunctionDecl>(SubstDecl(FD, FD->getParent(), MArgs));
3742 /// In the MS ABI, we need to instantiate default arguments of dllexported
3743 /// default constructors along with the constructor definition. This allows IR
3744 /// gen to emit a constructor closure which calls the default constructor with
3745 /// its default arguments.
3746 static void InstantiateDefaultCtorDefaultArgs(Sema &S,
3747 CXXConstructorDecl *Ctor) {
3748 assert(S.Context.getTargetInfo().getCXXABI().isMicrosoft() &&
3749 Ctor->isDefaultConstructor());
3750 unsigned NumParams = Ctor->getNumParams();
3753 DLLExportAttr *Attr = Ctor->getAttr<DLLExportAttr>();
3756 for (unsigned I = 0; I != NumParams; ++I) {
3757 (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), Ctor,
3758 Ctor->getParamDecl(I));
3759 S.DiscardCleanupsInEvaluationContext();
3763 /// Instantiate the definition of the given function from its
3766 /// \param PointOfInstantiation the point at which the instantiation was
3767 /// required. Note that this is not precisely a "point of instantiation"
3768 /// for the function, but it's close.
3770 /// \param Function the already-instantiated declaration of a
3771 /// function template specialization or member function of a class template
3774 /// \param Recursive if true, recursively instantiates any functions that
3775 /// are required by this instantiation.
3777 /// \param DefinitionRequired if true, then we are performing an explicit
3778 /// instantiation where the body of the function is required. Complain if
3779 /// there is no such body.
3780 void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
3781 FunctionDecl *Function,
3783 bool DefinitionRequired,
3785 if (Function->isInvalidDecl() || Function->isDefined() ||
3786 isa<CXXDeductionGuideDecl>(Function))
3789 // Never instantiate an explicit specialization except if it is a class scope
3790 // explicit specialization.
3791 TemplateSpecializationKind TSK = Function->getTemplateSpecializationKind();
3792 if (TSK == TSK_ExplicitSpecialization &&
3793 !Function->getClassScopeSpecializationPattern())
3796 // Find the function body that we'll be substituting.
3797 const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
3798 assert(PatternDecl && "instantiating a non-template");
3800 const FunctionDecl *PatternDef = PatternDecl->getDefinition();
3801 Stmt *Pattern = nullptr;
3803 Pattern = PatternDef->getBody(PatternDef);
3804 PatternDecl = PatternDef;
3805 if (PatternDef->willHaveBody())
3806 PatternDef = nullptr;
3809 // FIXME: We need to track the instantiation stack in order to know which
3810 // definitions should be visible within this instantiation.
3811 if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Function,
3812 Function->getInstantiatedFromMemberFunction(),
3813 PatternDecl, PatternDef, TSK,
3814 /*Complain*/DefinitionRequired)) {
3815 if (DefinitionRequired)
3816 Function->setInvalidDecl();
3817 else if (TSK == TSK_ExplicitInstantiationDefinition) {
3818 // Try again at the end of the translation unit (at which point a
3819 // definition will be required).
3821 Function->setInstantiationIsPending(true);
3822 PendingInstantiations.push_back(
3823 std::make_pair(Function, PointOfInstantiation));
3824 } else if (TSK == TSK_ImplicitInstantiation) {
3825 if (AtEndOfTU && !getDiagnostics().hasErrorOccurred() &&
3826 !getSourceManager().isInSystemHeader(PatternDecl->getLocStart())) {
3827 Diag(PointOfInstantiation, diag::warn_func_template_missing)
3829 Diag(PatternDecl->getLocation(), diag::note_forward_template_decl);
3830 if (getLangOpts().CPlusPlus11)
3831 Diag(PointOfInstantiation, diag::note_inst_declaration_hint)
3839 // Postpone late parsed template instantiations.
3840 if (PatternDecl->isLateTemplateParsed() &&
3841 !LateTemplateParser) {
3842 Function->setInstantiationIsPending(true);
3843 LateParsedInstantiations.push_back(
3844 std::make_pair(Function, PointOfInstantiation));
3848 // If we're performing recursive template instantiation, create our own
3849 // queue of pending implicit instantiations that we will instantiate later,
3850 // while we're still within our own instantiation context.
3851 // This has to happen before LateTemplateParser below is called, so that
3852 // it marks vtables used in late parsed templates as used.
3853 GlobalEagerInstantiationScope GlobalInstantiations(*this,
3854 /*Enabled=*/Recursive);
3855 LocalEagerInstantiationScope LocalInstantiations(*this);
3857 // Call the LateTemplateParser callback if there is a need to late parse
3858 // a templated function definition.
3859 if (!Pattern && PatternDecl->isLateTemplateParsed() &&
3860 LateTemplateParser) {
3861 // FIXME: Optimize to allow individual templates to be deserialized.
3862 if (PatternDecl->isFromASTFile())
3863 ExternalSource->ReadLateParsedTemplates(LateParsedTemplateMap);
3865 auto LPTIter = LateParsedTemplateMap.find(PatternDecl);
3866 assert(LPTIter != LateParsedTemplateMap.end() &&
3867 "missing LateParsedTemplate");
3868 LateTemplateParser(OpaqueParser, *LPTIter->second);
3869 Pattern = PatternDecl->getBody(PatternDecl);
3872 // Note, we should never try to instantiate a deleted function template.
3873 assert((Pattern || PatternDecl->isDefaulted() ||
3874 PatternDecl->hasSkippedBody()) &&
3875 "unexpected kind of function template definition");
3877 // C++1y [temp.explicit]p10:
3878 // Except for inline functions, declarations with types deduced from their
3879 // initializer or return value, and class template specializations, other
3880 // explicit instantiation declarations have the effect of suppressing the
3881 // implicit instantiation of the entity to which they refer.
3882 if (TSK == TSK_ExplicitInstantiationDeclaration &&
3883 !PatternDecl->isInlined() &&
3884 !PatternDecl->getReturnType()->getContainedAutoType())
3887 if (PatternDecl->isInlined()) {
3888 // Function, and all later redeclarations of it (from imported modules,
3889 // for instance), are now implicitly inline.
3890 for (auto *D = Function->getMostRecentDecl(); /**/;
3891 D = D->getPreviousDecl()) {
3892 D->setImplicitlyInline();
3898 InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
3899 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
3901 PrettyDeclStackTraceEntry CrashInfo(Context, Function, SourceLocation(),
3902 "instantiating function definition");
3904 // The instantiation is visible here, even if it was first declared in an
3905 // unimported module.
3906 Function->setVisibleDespiteOwningModule();
3908 // Copy the inner loc start from the pattern.
3909 Function->setInnerLocStart(PatternDecl->getInnerLocStart());
3911 EnterExpressionEvaluationContext EvalContext(
3912 *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
3914 // Introduce a new scope where local variable instantiations will be
3915 // recorded, unless we're actually a member function within a local
3916 // class, in which case we need to merge our results with the parent
3917 // scope (of the enclosing function).
3918 bool MergeWithParentScope = false;
3919 if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
3920 MergeWithParentScope = Rec->isLocalClass();
3922 LocalInstantiationScope Scope(*this, MergeWithParentScope);
3924 if (PatternDecl->isDefaulted())
3925 SetDeclDefaulted(Function, PatternDecl->getLocation());
3927 MultiLevelTemplateArgumentList TemplateArgs =
3928 getTemplateInstantiationArgs(Function, nullptr, false, PatternDecl);
3930 // Substitute into the qualifier; we can get a substitution failure here
3931 // through evil use of alias templates.
3932 // FIXME: Is CurContext correct for this? Should we go to the (instantiation
3933 // of the) lexical context of the pattern?
3934 SubstQualifier(*this, PatternDecl, Function, TemplateArgs);
3936 ActOnStartOfFunctionDef(nullptr, Function);
3938 // Enter the scope of this instantiation. We don't use
3939 // PushDeclContext because we don't have a scope.
3940 Sema::ContextRAII savedContext(*this, Function);
3942 if (addInstantiatedParametersToScope(*this, Function, PatternDecl, Scope,
3947 if (PatternDecl->hasSkippedBody()) {
3948 ActOnSkippedFunctionBody(Function);
3951 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Function)) {
3952 // If this is a constructor, instantiate the member initializers.
3953 InstantiateMemInitializers(Ctor, cast<CXXConstructorDecl>(PatternDecl),
3956 // If this is an MS ABI dllexport default constructor, instantiate any
3957 // default arguments.
3958 if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
3959 Ctor->isDefaultConstructor()) {
3960 InstantiateDefaultCtorDefaultArgs(*this, Ctor);
3964 // Instantiate the function body.
3965 Body = SubstStmt(Pattern, TemplateArgs);
3967 if (Body.isInvalid())
3968 Function->setInvalidDecl();
3970 // FIXME: finishing the function body while in an expression evaluation
3971 // context seems wrong. Investigate more.
3972 ActOnFinishFunctionBody(Function, Body.get(), /*IsInstantiation=*/true);
3974 PerformDependentDiagnostics(PatternDecl, TemplateArgs);
3976 if (auto *Listener = getASTMutationListener())
3977 Listener->FunctionDefinitionInstantiated(Function);
3982 DeclGroupRef DG(Function);
3983 Consumer.HandleTopLevelDecl(DG);
3985 // This class may have local implicit instantiations that need to be
3986 // instantiation within this scope.
3987 LocalInstantiations.perform();
3989 GlobalInstantiations.perform();
3992 VarTemplateSpecializationDecl *Sema::BuildVarTemplateInstantiation(
3993 VarTemplateDecl *VarTemplate, VarDecl *FromVar,
3994 const TemplateArgumentList &TemplateArgList,
3995 const TemplateArgumentListInfo &TemplateArgsInfo,
3996 SmallVectorImpl<TemplateArgument> &Converted,
3997 SourceLocation PointOfInstantiation, void *InsertPos,
3998 LateInstantiatedAttrVec *LateAttrs,
3999 LocalInstantiationScope *StartingScope) {
4000 if (FromVar->isInvalidDecl())
4003 InstantiatingTemplate Inst(*this, PointOfInstantiation, FromVar);
4004 if (Inst.isInvalid())
4007 MultiLevelTemplateArgumentList TemplateArgLists;
4008 TemplateArgLists.addOuterTemplateArguments(&TemplateArgList);
4010 // Instantiate the first declaration of the variable template: for a partial
4011 // specialization of a static data member template, the first declaration may
4012 // or may not be the declaration in the class; if it's in the class, we want
4013 // to instantiate a member in the class (a declaration), and if it's outside,
4014 // we want to instantiate a definition.
4016 // If we're instantiating an explicitly-specialized member template or member
4017 // partial specialization, don't do this. The member specialization completely
4018 // replaces the original declaration in this case.
4019 bool IsMemberSpec = false;
4020 if (VarTemplatePartialSpecializationDecl *PartialSpec =
4021 dyn_cast<VarTemplatePartialSpecializationDecl>(FromVar))
4022 IsMemberSpec = PartialSpec->isMemberSpecialization();
4023 else if (VarTemplateDecl *FromTemplate = FromVar->getDescribedVarTemplate())
4024 IsMemberSpec = FromTemplate->isMemberSpecialization();
4026 FromVar = FromVar->getFirstDecl();
4028 MultiLevelTemplateArgumentList MultiLevelList(TemplateArgList);
4029 TemplateDeclInstantiator Instantiator(*this, FromVar->getDeclContext(),
4032 // TODO: Set LateAttrs and StartingScope ...
4034 return cast_or_null<VarTemplateSpecializationDecl>(
4035 Instantiator.VisitVarTemplateSpecializationDecl(
4036 VarTemplate, FromVar, InsertPos, TemplateArgsInfo, Converted));
4039 /// Instantiates a variable template specialization by completing it
4040 /// with appropriate type information and initializer.
4041 VarTemplateSpecializationDecl *Sema::CompleteVarTemplateSpecializationDecl(
4042 VarTemplateSpecializationDecl *VarSpec, VarDecl *PatternDecl,
4043 const MultiLevelTemplateArgumentList &TemplateArgs) {
4044 assert(PatternDecl->isThisDeclarationADefinition() &&
4045 "don't have a definition to instantiate from");
4047 // Do substitution on the type of the declaration
4048 TypeSourceInfo *DI =
4049 SubstType(PatternDecl->getTypeSourceInfo(), TemplateArgs,
4050 PatternDecl->getTypeSpecStartLoc(), PatternDecl->getDeclName());
4054 // Update the type of this variable template specialization.
4055 VarSpec->setType(DI->getType());
4057 // Convert the declaration into a definition now.
4058 VarSpec->setCompleteDefinition();
4060 // Instantiate the initializer.
4061 InstantiateVariableInitializer(VarSpec, PatternDecl, TemplateArgs);
4066 /// BuildVariableInstantiation - Used after a new variable has been created.
4067 /// Sets basic variable data and decides whether to postpone the
4068 /// variable instantiation.
4069 void Sema::BuildVariableInstantiation(
4070 VarDecl *NewVar, VarDecl *OldVar,
4071 const MultiLevelTemplateArgumentList &TemplateArgs,
4072 LateInstantiatedAttrVec *LateAttrs, DeclContext *Owner,
4073 LocalInstantiationScope *StartingScope,
4074 bool InstantiatingVarTemplate) {
4076 // If we are instantiating a local extern declaration, the
4077 // instantiation belongs lexically to the containing function.
4078 // If we are instantiating a static data member defined
4079 // out-of-line, the instantiation will have the same lexical
4080 // context (which will be a namespace scope) as the template.
4081 if (OldVar->isLocalExternDecl()) {
4082 NewVar->setLocalExternDecl();
4083 NewVar->setLexicalDeclContext(Owner);
4084 } else if (OldVar->isOutOfLine())
4085 NewVar->setLexicalDeclContext(OldVar->getLexicalDeclContext());
4086 NewVar->setTSCSpec(OldVar->getTSCSpec());
4087 NewVar->setInitStyle(OldVar->getInitStyle());
4088 NewVar->setCXXForRangeDecl(OldVar->isCXXForRangeDecl());
4089 NewVar->setObjCForDecl(OldVar->isObjCForDecl());
4090 NewVar->setConstexpr(OldVar->isConstexpr());
4091 NewVar->setInitCapture(OldVar->isInitCapture());
4092 NewVar->setPreviousDeclInSameBlockScope(
4093 OldVar->isPreviousDeclInSameBlockScope());
4094 NewVar->setAccess(OldVar->getAccess());
4096 if (!OldVar->isStaticDataMember()) {
4097 if (OldVar->isUsed(false))
4098 NewVar->setIsUsed();
4099 NewVar->setReferenced(OldVar->isReferenced());
4102 InstantiateAttrs(TemplateArgs, OldVar, NewVar, LateAttrs, StartingScope);
4104 LookupResult Previous(
4105 *this, NewVar->getDeclName(), NewVar->getLocation(),
4106 NewVar->isLocalExternDecl() ? Sema::LookupRedeclarationWithLinkage
4107 : Sema::LookupOrdinaryName,
4108 NewVar->isLocalExternDecl() ? Sema::ForExternalRedeclaration
4109 : forRedeclarationInCurContext());
4111 if (NewVar->isLocalExternDecl() && OldVar->getPreviousDecl() &&
4112 (!OldVar->getPreviousDecl()->getDeclContext()->isDependentContext() ||
4113 OldVar->getPreviousDecl()->getDeclContext()==OldVar->getDeclContext())) {
4114 // We have a previous declaration. Use that one, so we merge with the
4116 if (NamedDecl *NewPrev = FindInstantiatedDecl(
4117 NewVar->getLocation(), OldVar->getPreviousDecl(), TemplateArgs))
4118 Previous.addDecl(NewPrev);
4119 } else if (!isa<VarTemplateSpecializationDecl>(NewVar) &&
4120 OldVar->hasLinkage())
4121 LookupQualifiedName(Previous, NewVar->getDeclContext(), false);
4122 CheckVariableDeclaration(NewVar, Previous);
4124 if (!InstantiatingVarTemplate) {
4125 NewVar->getLexicalDeclContext()->addHiddenDecl(NewVar);
4126 if (!NewVar->isLocalExternDecl() || !NewVar->getPreviousDecl())
4127 NewVar->getDeclContext()->makeDeclVisibleInContext(NewVar);
4130 if (!OldVar->isOutOfLine()) {
4131 if (NewVar->getDeclContext()->isFunctionOrMethod())
4132 CurrentInstantiationScope->InstantiatedLocal(OldVar, NewVar);
4135 // Link instantiations of static data members back to the template from
4136 // which they were instantiated.
4137 if (NewVar->isStaticDataMember() && !InstantiatingVarTemplate)
4138 NewVar->setInstantiationOfStaticDataMember(OldVar,
4139 TSK_ImplicitInstantiation);
4141 // Forward the mangling number from the template to the instantiated decl.
4142 Context.setManglingNumber(NewVar, Context.getManglingNumber(OldVar));
4143 Context.setStaticLocalNumber(NewVar, Context.getStaticLocalNumber(OldVar));
4145 // Delay instantiation of the initializer for variable templates or inline
4146 // static data members until a definition of the variable is needed. We need
4147 // it right away if the type contains 'auto'.
4148 if ((!isa<VarTemplateSpecializationDecl>(NewVar) &&
4149 !InstantiatingVarTemplate &&
4150 !(OldVar->isInline() && OldVar->isThisDeclarationADefinition() &&
4151 !NewVar->isThisDeclarationADefinition())) ||
4152 NewVar->getType()->isUndeducedType())
4153 InstantiateVariableInitializer(NewVar, OldVar, TemplateArgs);
4155 // Diagnose unused local variables with dependent types, where the diagnostic
4156 // will have been deferred.
4157 if (!NewVar->isInvalidDecl() &&
4158 NewVar->getDeclContext()->isFunctionOrMethod() &&
4159 OldVar->getType()->isDependentType())
4160 DiagnoseUnusedDecl(NewVar);
4163 /// Instantiate the initializer of a variable.
4164 void Sema::InstantiateVariableInitializer(
4165 VarDecl *Var, VarDecl *OldVar,
4166 const MultiLevelTemplateArgumentList &TemplateArgs) {
4167 if (ASTMutationListener *L = getASTContext().getASTMutationListener())
4168 L->VariableDefinitionInstantiated(Var);
4170 // We propagate the 'inline' flag with the initializer, because it
4171 // would otherwise imply that the variable is a definition for a
4172 // non-static data member.
4173 if (OldVar->isInlineSpecified())
4174 Var->setInlineSpecified();
4175 else if (OldVar->isInline())
4176 Var->setImplicitlyInline();
4178 if (OldVar->getInit()) {
4179 EnterExpressionEvaluationContext Evaluated(
4180 *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated, Var);
4182 // Instantiate the initializer.
4186 ContextRAII SwitchContext(*this, Var->getDeclContext());
4187 Init = SubstInitializer(OldVar->getInit(), TemplateArgs,
4188 OldVar->getInitStyle() == VarDecl::CallInit);
4191 if (!Init.isInvalid()) {
4192 Expr *InitExpr = Init.get();
4194 if (Var->hasAttr<DLLImportAttr>() &&
4196 !InitExpr->isConstantInitializer(getASTContext(), false))) {
4197 // Do not dynamically initialize dllimport variables.
4198 } else if (InitExpr) {
4199 bool DirectInit = OldVar->isDirectInit();
4200 AddInitializerToDecl(Var, InitExpr, DirectInit);
4202 ActOnUninitializedDecl(Var);
4204 // FIXME: Not too happy about invalidating the declaration
4205 // because of a bogus initializer.
4206 Var->setInvalidDecl();
4209 // `inline` variables are a definition and declaration all in one; we won't
4210 // pick up an initializer from anywhere else.
4211 if (Var->isStaticDataMember() && !Var->isInline()) {
4212 if (!Var->isOutOfLine())
4215 // If the declaration inside the class had an initializer, don't add
4216 // another one to the out-of-line definition.
4217 if (OldVar->getFirstDecl()->hasInit())
4221 // We'll add an initializer to a for-range declaration later.
4222 if (Var->isCXXForRangeDecl() || Var->isObjCForDecl())
4225 ActOnUninitializedDecl(Var);
4228 if (getLangOpts().CUDA)
4229 checkAllowedCUDAInitializer(Var);
4232 /// Instantiate the definition of the given variable from its
4235 /// \param PointOfInstantiation the point at which the instantiation was
4236 /// required. Note that this is not precisely a "point of instantiation"
4237 /// for the variable, but it's close.
4239 /// \param Var the already-instantiated declaration of a templated variable.
4241 /// \param Recursive if true, recursively instantiates any functions that
4242 /// are required by this instantiation.
4244 /// \param DefinitionRequired if true, then we are performing an explicit
4245 /// instantiation where a definition of the variable is required. Complain
4246 /// if there is no such definition.
4247 void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
4248 VarDecl *Var, bool Recursive,
4249 bool DefinitionRequired, bool AtEndOfTU) {
4250 if (Var->isInvalidDecl())
4253 VarTemplateSpecializationDecl *VarSpec =
4254 dyn_cast<VarTemplateSpecializationDecl>(Var);
4255 VarDecl *PatternDecl = nullptr, *Def = nullptr;
4256 MultiLevelTemplateArgumentList TemplateArgs =
4257 getTemplateInstantiationArgs(Var);
4260 // If this is a variable template specialization, make sure that it is
4261 // non-dependent, then find its instantiation pattern.
4262 bool InstantiationDependent = false;
4263 assert(!TemplateSpecializationType::anyDependentTemplateArguments(
4264 VarSpec->getTemplateArgsInfo(), InstantiationDependent) &&
4265 "Only instantiate variable template specializations that are "
4266 "not type-dependent");
4267 (void)InstantiationDependent;
4269 // Find the variable initialization that we'll be substituting. If the
4270 // pattern was instantiated from a member template, look back further to
4271 // find the real pattern.
4272 assert(VarSpec->getSpecializedTemplate() &&
4273 "Specialization without specialized template?");
4274 llvm::PointerUnion<VarTemplateDecl *,
4275 VarTemplatePartialSpecializationDecl *> PatternPtr =
4276 VarSpec->getSpecializedTemplateOrPartial();
4277 if (PatternPtr.is<VarTemplatePartialSpecializationDecl *>()) {
4278 VarTemplatePartialSpecializationDecl *Tmpl =
4279 PatternPtr.get<VarTemplatePartialSpecializationDecl *>();
4280 while (VarTemplatePartialSpecializationDecl *From =
4281 Tmpl->getInstantiatedFromMember()) {
4282 if (Tmpl->isMemberSpecialization())
4289 VarTemplateDecl *Tmpl = PatternPtr.get<VarTemplateDecl *>();
4290 while (VarTemplateDecl *From =
4291 Tmpl->getInstantiatedFromMemberTemplate()) {
4292 if (Tmpl->isMemberSpecialization())
4297 PatternDecl = Tmpl->getTemplatedDecl();
4300 // If this is a static data member template, there might be an
4301 // uninstantiated initializer on the declaration. If so, instantiate
4304 // FIXME: This largely duplicates what we would do below. The difference
4305 // is that along this path we may instantiate an initializer from an
4306 // in-class declaration of the template and instantiate the definition
4307 // from a separate out-of-class definition.
4308 if (PatternDecl->isStaticDataMember() &&
4309 (PatternDecl = PatternDecl->getFirstDecl())->hasInit() &&
4311 // FIXME: Factor out the duplicated instantiation context setup/tear down
4313 InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
4314 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
4316 PrettyDeclStackTraceEntry CrashInfo(Context, Var, SourceLocation(),
4317 "instantiating variable initializer");
4319 // The instantiation is visible here, even if it was first declared in an
4320 // unimported module.
4321 Var->setVisibleDespiteOwningModule();
4323 // If we're performing recursive template instantiation, create our own
4324 // queue of pending implicit instantiations that we will instantiate
4325 // later, while we're still within our own instantiation context.
4326 GlobalEagerInstantiationScope GlobalInstantiations(*this,
4327 /*Enabled=*/Recursive);
4328 LocalInstantiationScope Local(*this);
4329 LocalEagerInstantiationScope LocalInstantiations(*this);
4331 // Enter the scope of this instantiation. We don't use
4332 // PushDeclContext because we don't have a scope.
4333 ContextRAII PreviousContext(*this, Var->getDeclContext());
4334 InstantiateVariableInitializer(Var, PatternDecl, TemplateArgs);
4335 PreviousContext.pop();
4337 // This variable may have local implicit instantiations that need to be
4338 // instantiated within this scope.
4339 LocalInstantiations.perform();
4341 GlobalInstantiations.perform();
4344 // Find actual definition
4345 Def = PatternDecl->getDefinition(getASTContext());
4347 // If this is a static data member, find its out-of-line definition.
4348 assert(Var->isStaticDataMember() && "not a static data member?");
4349 PatternDecl = Var->getInstantiatedFromStaticDataMember();
4351 assert(PatternDecl && "data member was not instantiated from a template?");
4352 assert(PatternDecl->isStaticDataMember() && "not a static data member?");
4353 Def = PatternDecl->getDefinition();
4356 TemplateSpecializationKind TSK = Var->getTemplateSpecializationKind();
4358 // If we don't have a definition of the variable template, we won't perform
4359 // any instantiation. Rather, we rely on the user to instantiate this
4360 // definition (or provide a specialization for it) in another translation
4362 if (!Def && !DefinitionRequired) {
4363 if (TSK == TSK_ExplicitInstantiationDefinition) {
4364 PendingInstantiations.push_back(
4365 std::make_pair(Var, PointOfInstantiation));
4366 } else if (TSK == TSK_ImplicitInstantiation) {
4367 // Warn about missing definition at the end of translation unit.
4368 if (AtEndOfTU && !getDiagnostics().hasErrorOccurred() &&
4369 !getSourceManager().isInSystemHeader(PatternDecl->getLocStart())) {
4370 Diag(PointOfInstantiation, diag::warn_var_template_missing)
4372 Diag(PatternDecl->getLocation(), diag::note_forward_template_decl);
4373 if (getLangOpts().CPlusPlus11)
4374 Diag(PointOfInstantiation, diag::note_inst_declaration_hint) << Var;
4381 // FIXME: We need to track the instantiation stack in order to know which
4382 // definitions should be visible within this instantiation.
4383 // FIXME: Produce diagnostics when Var->getInstantiatedFromStaticDataMember().
4384 if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Var,
4385 /*InstantiatedFromMember*/false,
4386 PatternDecl, Def, TSK,
4387 /*Complain*/DefinitionRequired))
4391 // Never instantiate an explicit specialization.
4392 if (TSK == TSK_ExplicitSpecialization)
4395 // C++11 [temp.explicit]p10:
4396 // Except for inline functions, const variables of literal types, variables
4397 // of reference types, [...] explicit instantiation declarations
4398 // have the effect of suppressing the implicit instantiation of the entity
4399 // to which they refer.
4400 if (TSK == TSK_ExplicitInstantiationDeclaration &&
4401 !Var->isUsableInConstantExpressions(getASTContext()))
4404 // Make sure to pass the instantiated variable to the consumer at the end.
4405 struct PassToConsumerRAII {
4406 ASTConsumer &Consumer;
4409 PassToConsumerRAII(ASTConsumer &Consumer, VarDecl *Var)
4410 : Consumer(Consumer), Var(Var) { }
4412 ~PassToConsumerRAII() {
4413 Consumer.HandleCXXStaticMemberVarInstantiation(Var);
4415 } PassToConsumerRAII(Consumer, Var);
4417 // If we already have a definition, we're done.
4418 if (VarDecl *Def = Var->getDefinition()) {
4419 // We may be explicitly instantiating something we've already implicitly
4421 Def->setTemplateSpecializationKind(Var->getTemplateSpecializationKind(),
4422 PointOfInstantiation);
4426 InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
4427 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
4429 PrettyDeclStackTraceEntry CrashInfo(Context, Var, SourceLocation(),
4430 "instantiating variable definition");
4432 // If we're performing recursive template instantiation, create our own
4433 // queue of pending implicit instantiations that we will instantiate later,
4434 // while we're still within our own instantiation context.
4435 GlobalEagerInstantiationScope GlobalInstantiations(*this,
4436 /*Enabled=*/Recursive);
4438 // Enter the scope of this instantiation. We don't use
4439 // PushDeclContext because we don't have a scope.
4440 ContextRAII PreviousContext(*this, Var->getDeclContext());
4441 LocalInstantiationScope Local(*this);
4443 LocalEagerInstantiationScope LocalInstantiations(*this);
4445 VarDecl *OldVar = Var;
4446 if (Def->isStaticDataMember() && !Def->isOutOfLine()) {
4447 // We're instantiating an inline static data member whose definition was
4448 // provided inside the class.
4449 InstantiateVariableInitializer(Var, Def, TemplateArgs);
4450 } else if (!VarSpec) {
4451 Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
4453 } else if (Var->isStaticDataMember() &&
4454 Var->getLexicalDeclContext()->isRecord()) {
4455 // We need to instantiate the definition of a static data member template,
4456 // and all we have is the in-class declaration of it. Instantiate a separate
4457 // declaration of the definition.
4458 TemplateDeclInstantiator Instantiator(*this, Var->getDeclContext(),
4460 Var = cast_or_null<VarDecl>(Instantiator.VisitVarTemplateSpecializationDecl(
4461 VarSpec->getSpecializedTemplate(), Def, nullptr,
4462 VarSpec->getTemplateArgsInfo(), VarSpec->getTemplateArgs().asArray()));
4464 llvm::PointerUnion<VarTemplateDecl *,
4465 VarTemplatePartialSpecializationDecl *> PatternPtr =
4466 VarSpec->getSpecializedTemplateOrPartial();
4467 if (VarTemplatePartialSpecializationDecl *Partial =
4468 PatternPtr.dyn_cast<VarTemplatePartialSpecializationDecl *>())
4469 cast<VarTemplateSpecializationDecl>(Var)->setInstantiationOf(
4470 Partial, &VarSpec->getTemplateInstantiationArgs());
4472 // Merge the definition with the declaration.
4473 LookupResult R(*this, Var->getDeclName(), Var->getLocation(),
4474 LookupOrdinaryName, forRedeclarationInCurContext());
4476 MergeVarDecl(Var, R);
4478 // Attach the initializer.
4479 InstantiateVariableInitializer(Var, Def, TemplateArgs);
4482 // Complete the existing variable's definition with an appropriately
4483 // substituted type and initializer.
4484 Var = CompleteVarTemplateSpecializationDecl(VarSpec, Def, TemplateArgs);
4486 PreviousContext.pop();
4489 PassToConsumerRAII.Var = Var;
4490 Var->setTemplateSpecializationKind(OldVar->getTemplateSpecializationKind(),
4491 OldVar->getPointOfInstantiation());
4494 // This variable may have local implicit instantiations that need to be
4495 // instantiated within this scope.
4496 LocalInstantiations.perform();
4498 GlobalInstantiations.perform();
4502 Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
4503 const CXXConstructorDecl *Tmpl,
4504 const MultiLevelTemplateArgumentList &TemplateArgs) {
4506 SmallVector<CXXCtorInitializer*, 4> NewInits;
4507 bool AnyErrors = Tmpl->isInvalidDecl();
4509 // Instantiate all the initializers.
4510 for (const auto *Init : Tmpl->inits()) {
4511 // Only instantiate written initializers, let Sema re-construct implicit
4513 if (!Init->isWritten())
4516 SourceLocation EllipsisLoc;
4518 if (Init->isPackExpansion()) {
4519 // This is a pack expansion. We should expand it now.
4520 TypeLoc BaseTL = Init->getTypeSourceInfo()->getTypeLoc();
4521 SmallVector<UnexpandedParameterPack, 4> Unexpanded;
4522 collectUnexpandedParameterPacks(BaseTL, Unexpanded);
4523 collectUnexpandedParameterPacks(Init->getInit(), Unexpanded);
4524 bool ShouldExpand = false;
4525 bool RetainExpansion = false;
4526 Optional<unsigned> NumExpansions;
4527 if (CheckParameterPacksForExpansion(Init->getEllipsisLoc(),
4528 BaseTL.getSourceRange(),
4530 TemplateArgs, ShouldExpand,
4534 New->setInvalidDecl();
4537 assert(ShouldExpand && "Partial instantiation of base initializer?");
4539 // Loop over all of the arguments in the argument pack(s),
4540 for (unsigned I = 0; I != *NumExpansions; ++I) {
4541 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, I);
4543 // Instantiate the initializer.
4544 ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs,
4545 /*CXXDirectInit=*/true);
4546 if (TempInit.isInvalid()) {
4551 // Instantiate the base type.
4552 TypeSourceInfo *BaseTInfo = SubstType(Init->getTypeSourceInfo(),
4554 Init->getSourceLocation(),
4555 New->getDeclName());
4561 // Build the initializer.
4562 MemInitResult NewInit = BuildBaseInitializer(BaseTInfo->getType(),
4563 BaseTInfo, TempInit.get(),
4566 if (NewInit.isInvalid()) {
4571 NewInits.push_back(NewInit.get());
4577 // Instantiate the initializer.
4578 ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs,
4579 /*CXXDirectInit=*/true);
4580 if (TempInit.isInvalid()) {
4585 MemInitResult NewInit;
4586 if (Init->isDelegatingInitializer() || Init->isBaseInitializer()) {
4587 TypeSourceInfo *TInfo = SubstType(Init->getTypeSourceInfo(),
4589 Init->getSourceLocation(),
4590 New->getDeclName());
4593 New->setInvalidDecl();
4597 if (Init->isBaseInitializer())
4598 NewInit = BuildBaseInitializer(TInfo->getType(), TInfo, TempInit.get(),
4599 New->getParent(), EllipsisLoc);
4601 NewInit = BuildDelegatingInitializer(TInfo, TempInit.get(),
4602 cast<CXXRecordDecl>(CurContext->getParent()));
4603 } else if (Init->isMemberInitializer()) {
4604 FieldDecl *Member = cast_or_null<FieldDecl>(FindInstantiatedDecl(
4605 Init->getMemberLocation(),
4610 New->setInvalidDecl();
4614 NewInit = BuildMemberInitializer(Member, TempInit.get(),
4615 Init->getSourceLocation());
4616 } else if (Init->isIndirectMemberInitializer()) {
4617 IndirectFieldDecl *IndirectMember =
4618 cast_or_null<IndirectFieldDecl>(FindInstantiatedDecl(
4619 Init->getMemberLocation(),
4620 Init->getIndirectMember(), TemplateArgs));
4622 if (!IndirectMember) {
4624 New->setInvalidDecl();
4628 NewInit = BuildMemberInitializer(IndirectMember, TempInit.get(),
4629 Init->getSourceLocation());
4632 if (NewInit.isInvalid()) {
4634 New->setInvalidDecl();
4636 NewInits.push_back(NewInit.get());
4640 // Assign all the initializers to the new constructor.
4641 ActOnMemInitializers(New,
4642 /*FIXME: ColonLoc */
4648 // TODO: this could be templated if the various decl types used the
4649 // same method name.
4650 static bool isInstantiationOf(ClassTemplateDecl *Pattern,
4651 ClassTemplateDecl *Instance) {
4652 Pattern = Pattern->getCanonicalDecl();
4655 Instance = Instance->getCanonicalDecl();
4656 if (Pattern == Instance) return true;
4657 Instance = Instance->getInstantiatedFromMemberTemplate();
4663 static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
4664 FunctionTemplateDecl *Instance) {
4665 Pattern = Pattern->getCanonicalDecl();
4668 Instance = Instance->getCanonicalDecl();
4669 if (Pattern == Instance) return true;
4670 Instance = Instance->getInstantiatedFromMemberTemplate();
4677 isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
4678 ClassTemplatePartialSpecializationDecl *Instance) {
4680 = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
4682 Instance = cast<ClassTemplatePartialSpecializationDecl>(
4683 Instance->getCanonicalDecl());
4684 if (Pattern == Instance)
4686 Instance = Instance->getInstantiatedFromMember();
4692 static bool isInstantiationOf(CXXRecordDecl *Pattern,
4693 CXXRecordDecl *Instance) {
4694 Pattern = Pattern->getCanonicalDecl();
4697 Instance = Instance->getCanonicalDecl();
4698 if (Pattern == Instance) return true;
4699 Instance = Instance->getInstantiatedFromMemberClass();
4705 static bool isInstantiationOf(FunctionDecl *Pattern,
4706 FunctionDecl *Instance) {
4707 Pattern = Pattern->getCanonicalDecl();
4710 Instance = Instance->getCanonicalDecl();
4711 if (Pattern == Instance) return true;
4712 Instance = Instance->getInstantiatedFromMemberFunction();
4718 static bool isInstantiationOf(EnumDecl *Pattern,
4719 EnumDecl *Instance) {
4720 Pattern = Pattern->getCanonicalDecl();
4723 Instance = Instance->getCanonicalDecl();
4724 if (Pattern == Instance) return true;
4725 Instance = Instance->getInstantiatedFromMemberEnum();
4731 static bool isInstantiationOf(UsingShadowDecl *Pattern,
4732 UsingShadowDecl *Instance,
4734 return declaresSameEntity(C.getInstantiatedFromUsingShadowDecl(Instance),
4738 static bool isInstantiationOf(UsingDecl *Pattern, UsingDecl *Instance,
4740 return declaresSameEntity(C.getInstantiatedFromUsingDecl(Instance), Pattern);
4743 template<typename T>
4744 static bool isInstantiationOfUnresolvedUsingDecl(T *Pattern, Decl *Other,
4746 // An unresolved using declaration can instantiate to an unresolved using
4747 // declaration, or to a using declaration or a using declaration pack.
4749 // Multiple declarations can claim to be instantiated from an unresolved
4750 // using declaration if it's a pack expansion. We want the UsingPackDecl
4751 // in that case, not the individual UsingDecls within the pack.
4752 bool OtherIsPackExpansion;
4753 NamedDecl *OtherFrom;
4754 if (auto *OtherUUD = dyn_cast<T>(Other)) {
4755 OtherIsPackExpansion = OtherUUD->isPackExpansion();
4756 OtherFrom = Ctx.getInstantiatedFromUsingDecl(OtherUUD);
4757 } else if (auto *OtherUPD = dyn_cast<UsingPackDecl>(Other)) {
4758 OtherIsPackExpansion = true;
4759 OtherFrom = OtherUPD->getInstantiatedFromUsingDecl();
4760 } else if (auto *OtherUD = dyn_cast<UsingDecl>(Other)) {
4761 OtherIsPackExpansion = false;
4762 OtherFrom = Ctx.getInstantiatedFromUsingDecl(OtherUD);
4766 return Pattern->isPackExpansion() == OtherIsPackExpansion &&
4767 declaresSameEntity(OtherFrom, Pattern);
4770 static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
4771 VarDecl *Instance) {
4772 assert(Instance->isStaticDataMember());
4774 Pattern = Pattern->getCanonicalDecl();
4777 Instance = Instance->getCanonicalDecl();
4778 if (Pattern == Instance) return true;
4779 Instance = Instance->getInstantiatedFromStaticDataMember();
4785 // Other is the prospective instantiation
4786 // D is the prospective pattern
4787 static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
4788 if (auto *UUD = dyn_cast<UnresolvedUsingTypenameDecl>(D))
4789 return isInstantiationOfUnresolvedUsingDecl(UUD, Other, Ctx);
4791 if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(D))
4792 return isInstantiationOfUnresolvedUsingDecl(UUD, Other, Ctx);
4794 if (D->getKind() != Other->getKind())
4797 if (auto *Record = dyn_cast<CXXRecordDecl>(Other))
4798 return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
4800 if (auto *Function = dyn_cast<FunctionDecl>(Other))
4801 return isInstantiationOf(cast<FunctionDecl>(D), Function);
4803 if (auto *Enum = dyn_cast<EnumDecl>(Other))
4804 return isInstantiationOf(cast<EnumDecl>(D), Enum);
4806 if (auto *Var = dyn_cast<VarDecl>(Other))
4807 if (Var->isStaticDataMember())
4808 return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
4810 if (auto *Temp = dyn_cast<ClassTemplateDecl>(Other))
4811 return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
4813 if (auto *Temp = dyn_cast<FunctionTemplateDecl>(Other))
4814 return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
4816 if (auto *PartialSpec =
4817 dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
4818 return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
4821 if (auto *Field = dyn_cast<FieldDecl>(Other)) {
4822 if (!Field->getDeclName()) {
4823 // This is an unnamed field.
4824 return declaresSameEntity(Ctx.getInstantiatedFromUnnamedFieldDecl(Field),
4825 cast<FieldDecl>(D));
4829 if (auto *Using = dyn_cast<UsingDecl>(Other))
4830 return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
4832 if (auto *Shadow = dyn_cast<UsingShadowDecl>(Other))
4833 return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
4835 return D->getDeclName() &&
4836 D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
4839 template<typename ForwardIterator>
4840 static NamedDecl *findInstantiationOf(ASTContext &Ctx,
4842 ForwardIterator first,
4843 ForwardIterator last) {
4844 for (; first != last; ++first)
4845 if (isInstantiationOf(Ctx, D, *first))
4846 return cast<NamedDecl>(*first);
4851 /// Finds the instantiation of the given declaration context
4852 /// within the current instantiation.
4854 /// \returns NULL if there was an error
4855 DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
4856 const MultiLevelTemplateArgumentList &TemplateArgs) {
4857 if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
4858 Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs, true);
4859 return cast_or_null<DeclContext>(ID);
4863 /// Find the instantiation of the given declaration within the
4864 /// current instantiation.
4866 /// This routine is intended to be used when \p D is a declaration
4867 /// referenced from within a template, that needs to mapped into the
4868 /// corresponding declaration within an instantiation. For example,
4872 /// template<typename T>
4875 /// KnownValue = sizeof(T)
4878 /// bool getKind() const { return KnownValue; }
4881 /// template struct X<int>;
4884 /// In the instantiation of <tt>X<int>::getKind()</tt>, we need to map the
4885 /// \p EnumConstantDecl for \p KnownValue (which refers to
4886 /// <tt>X<T>::<Kind>::KnownValue</tt>) to its instantiation
4887 /// (<tt>X<int>::<Kind>::KnownValue</tt>). \p FindInstantiatedDecl performs
4888 /// this mapping from within the instantiation of <tt>X<int></tt>.
4889 NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
4890 const MultiLevelTemplateArgumentList &TemplateArgs,
4891 bool FindingInstantiatedContext) {
4892 DeclContext *ParentDC = D->getDeclContext();
4893 // FIXME: Parmeters of pointer to functions (y below) that are themselves
4894 // parameters (p below) can have their ParentDC set to the translation-unit
4895 // - thus we can not consistently check if the ParentDC of such a parameter
4896 // is Dependent or/and a FunctionOrMethod.
4897 // For e.g. this code, during Template argument deduction tries to
4898 // find an instantiated decl for (T y) when the ParentDC for y is
4899 // the translation unit.
4900 // e.g. template <class T> void Foo(auto (*p)(T y) -> decltype(y())) {}
4901 // float baz(float(*)()) { return 0.0; }
4903 // The better fix here is perhaps to ensure that a ParmVarDecl, by the time
4904 // it gets here, always has a FunctionOrMethod as its ParentDC??
4906 // - as long as we have a ParmVarDecl whose parent is non-dependent and
4907 // whose type is not instantiation dependent, do nothing to the decl
4908 // - otherwise find its instantiated decl.
4909 if (isa<ParmVarDecl>(D) && !ParentDC->isDependentContext() &&
4910 !cast<ParmVarDecl>(D)->getType()->isInstantiationDependentType())
4912 if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
4913 isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
4914 (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext()) ||
4915 (isa<CXXRecordDecl>(D) && cast<CXXRecordDecl>(D)->isLambda())) {
4916 // D is a local of some kind. Look into the map of local
4917 // declarations to their instantiations.
4918 if (CurrentInstantiationScope) {
4919 if (auto Found = CurrentInstantiationScope->findInstantiationOf(D)) {
4920 if (Decl *FD = Found->dyn_cast<Decl *>())
4921 return cast<NamedDecl>(FD);
4923 int PackIdx = ArgumentPackSubstitutionIndex;
4924 assert(PackIdx != -1 &&
4925 "found declaration pack but not pack expanding");
4926 typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack;
4927 return cast<NamedDecl>((*Found->get<DeclArgumentPack *>())[PackIdx]);
4931 // If we're performing a partial substitution during template argument
4932 // deduction, we may not have values for template parameters yet. They
4933 // just map to themselves.
4934 if (isa<NonTypeTemplateParmDecl>(D) || isa<TemplateTypeParmDecl>(D) ||
4935 isa<TemplateTemplateParmDecl>(D))
4938 if (D->isInvalidDecl())
4941 // Normally this function only searches for already instantiated declaration
4942 // however we have to make an exclusion for local types used before
4943 // definition as in the code:
4945 // template<typename T> void f1() {
4946 // void g1(struct x1);
4950 // In this case instantiation of the type of 'g1' requires definition of
4951 // 'x1', which is defined later. Error recovery may produce an enum used
4952 // before definition. In these cases we need to instantiate relevant
4953 // declarations here.
4954 bool NeedInstantiate = false;
4955 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D))
4956 NeedInstantiate = RD->isLocalClass();
4958 NeedInstantiate = isa<EnumDecl>(D);
4959 if (NeedInstantiate) {
4960 Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
4961 CurrentInstantiationScope->InstantiatedLocal(D, Inst);
4962 return cast<TypeDecl>(Inst);
4965 // If we didn't find the decl, then we must have a label decl that hasn't
4966 // been found yet. Lazily instantiate it and return it now.
4967 assert(isa<LabelDecl>(D));
4969 Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
4970 assert(Inst && "Failed to instantiate label??");
4972 CurrentInstantiationScope->InstantiatedLocal(D, Inst);
4973 return cast<LabelDecl>(Inst);
4976 // For variable template specializations, update those that are still
4978 if (VarTemplateSpecializationDecl *VarSpec =
4979 dyn_cast<VarTemplateSpecializationDecl>(D)) {
4980 bool InstantiationDependent = false;
4981 const TemplateArgumentListInfo &VarTemplateArgs =
4982 VarSpec->getTemplateArgsInfo();
4983 if (TemplateSpecializationType::anyDependentTemplateArguments(
4984 VarTemplateArgs, InstantiationDependent))
4985 D = cast<NamedDecl>(
4986 SubstDecl(D, VarSpec->getDeclContext(), TemplateArgs));
4990 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
4991 if (!Record->isDependentContext())
4994 // Determine whether this record is the "templated" declaration describing
4995 // a class template or class template partial specialization.
4996 ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
4998 ClassTemplate = ClassTemplate->getCanonicalDecl();
4999 else if (ClassTemplatePartialSpecializationDecl *PartialSpec
5000 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record))
5001 ClassTemplate = PartialSpec->getSpecializedTemplate()->getCanonicalDecl();
5003 // Walk the current context to find either the record or an instantiation of
5005 DeclContext *DC = CurContext;
5006 while (!DC->isFileContext()) {
5007 // If we're performing substitution while we're inside the template
5008 // definition, we'll find our own context. We're done.
5009 if (DC->Equals(Record))
5012 if (CXXRecordDecl *InstRecord = dyn_cast<CXXRecordDecl>(DC)) {
5013 // Check whether we're in the process of instantiating a class template
5014 // specialization of the template we're mapping.
5015 if (ClassTemplateSpecializationDecl *InstSpec
5016 = dyn_cast<ClassTemplateSpecializationDecl>(InstRecord)){
5017 ClassTemplateDecl *SpecTemplate = InstSpec->getSpecializedTemplate();
5018 if (ClassTemplate && isInstantiationOf(ClassTemplate, SpecTemplate))
5022 // Check whether we're in the process of instantiating a member class.
5023 if (isInstantiationOf(Record, InstRecord))
5027 // Move to the outer template scope.
5028 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) {
5029 if (FD->getFriendObjectKind() && FD->getDeclContext()->isFileContext()){
5030 DC = FD->getLexicalDeclContext();
5033 // An implicit deduction guide acts as if it's within the class template
5034 // specialization described by its name and first N template params.
5035 auto *Guide = dyn_cast<CXXDeductionGuideDecl>(FD);
5036 if (Guide && Guide->isImplicit()) {
5037 TemplateDecl *TD = Guide->getDeducedTemplate();
5038 // Convert the arguments to an "as-written" list.
5039 TemplateArgumentListInfo Args(Loc, Loc);
5040 for (TemplateArgument Arg : TemplateArgs.getInnermost().take_front(
5041 TD->getTemplateParameters()->size())) {
5042 ArrayRef<TemplateArgument> Unpacked(Arg);
5043 if (Arg.getKind() == TemplateArgument::Pack)
5044 Unpacked = Arg.pack_elements();
5045 for (TemplateArgument UnpackedArg : Unpacked)
5047 getTrivialTemplateArgumentLoc(UnpackedArg, QualType(), Loc));
5049 QualType T = CheckTemplateIdType(TemplateName(TD), Loc, Args);
5052 auto *SubstRecord = T->getAsCXXRecordDecl();
5053 assert(SubstRecord && "class template id not a class type?");
5054 // Check that this template-id names the primary template and not a
5055 // partial or explicit specialization. (In the latter cases, it's
5056 // meaningless to attempt to find an instantiation of D within the
5058 // FIXME: The standard doesn't say what should happen here.
5059 if (FindingInstantiatedContext &&
5060 usesPartialOrExplicitSpecialization(
5061 Loc, cast<ClassTemplateSpecializationDecl>(SubstRecord))) {
5062 Diag(Loc, diag::err_specialization_not_primary_template)
5063 << T << (SubstRecord->getTemplateSpecializationKind() ==
5064 TSK_ExplicitSpecialization);
5072 DC = DC->getParent();
5075 // Fall through to deal with other dependent record types (e.g.,
5076 // anonymous unions in class templates).
5079 if (!ParentDC->isDependentContext())
5082 ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
5086 if (ParentDC != D->getDeclContext()) {
5087 // We performed some kind of instantiation in the parent context,
5088 // so now we need to look into the instantiated parent context to
5089 // find the instantiation of the declaration D.
5091 // If our context used to be dependent, we may need to instantiate
5092 // it before performing lookup into that context.
5093 bool IsBeingInstantiated = false;
5094 if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
5095 if (!Spec->isDependentContext()) {
5096 QualType T = Context.getTypeDeclType(Spec);
5097 const RecordType *Tag = T->getAs<RecordType>();
5098 assert(Tag && "type of non-dependent record is not a RecordType");
5099 if (Tag->isBeingDefined())
5100 IsBeingInstantiated = true;
5101 if (!Tag->isBeingDefined() &&
5102 RequireCompleteType(Loc, T, diag::err_incomplete_type))
5105 ParentDC = Tag->getDecl();
5109 NamedDecl *Result = nullptr;
5110 // FIXME: If the name is a dependent name, this lookup won't necessarily
5111 // find it. Does that ever matter?
5112 if (auto Name = D->getDeclName()) {
5113 DeclarationNameInfo NameInfo(Name, D->getLocation());
5114 Name = SubstDeclarationNameInfo(NameInfo, TemplateArgs).getName();
5117 DeclContext::lookup_result Found = ParentDC->lookup(Name);
5118 Result = findInstantiationOf(Context, D, Found.begin(), Found.end());
5120 // Since we don't have a name for the entity we're looking for,
5121 // our only option is to walk through all of the declarations to
5122 // find that name. This will occur in a few cases:
5124 // - anonymous struct/union within a template
5125 // - unnamed class/struct/union/enum within a template
5127 // FIXME: Find a better way to find these instantiations!
5128 Result = findInstantiationOf(Context, D,
5129 ParentDC->decls_begin(),
5130 ParentDC->decls_end());
5134 if (isa<UsingShadowDecl>(D)) {
5135 // UsingShadowDecls can instantiate to nothing because of using hiding.
5136 } else if (Diags.hasErrorOccurred()) {
5137 // We've already complained about something, so most likely this
5138 // declaration failed to instantiate. There's no point in complaining
5139 // further, since this is normal in invalid code.
5140 } else if (IsBeingInstantiated) {
5141 // The class in which this member exists is currently being
5142 // instantiated, and we haven't gotten around to instantiating this
5143 // member yet. This can happen when the code uses forward declarations
5144 // of member classes, and introduces ordering dependencies via
5145 // template instantiation.
5146 Diag(Loc, diag::err_member_not_yet_instantiated)
5148 << Context.getTypeDeclType(cast<CXXRecordDecl>(ParentDC));
5149 Diag(D->getLocation(), diag::note_non_instantiated_member_here);
5150 } else if (EnumConstantDecl *ED = dyn_cast<EnumConstantDecl>(D)) {
5151 // This enumeration constant was found when the template was defined,
5152 // but can't be found in the instantiation. This can happen if an
5153 // unscoped enumeration member is explicitly specialized.
5154 EnumDecl *Enum = cast<EnumDecl>(ED->getLexicalDeclContext());
5155 EnumDecl *Spec = cast<EnumDecl>(FindInstantiatedDecl(Loc, Enum,
5157 assert(Spec->getTemplateSpecializationKind() ==
5158 TSK_ExplicitSpecialization);
5159 Diag(Loc, diag::err_enumerator_does_not_exist)
5161 << Context.getTypeDeclType(cast<TypeDecl>(Spec->getDeclContext()));
5162 Diag(Spec->getLocation(), diag::note_enum_specialized_here)
5163 << Context.getTypeDeclType(Spec);
5165 // We should have found something, but didn't.
5166 llvm_unreachable("Unable to find instantiation of declaration!");
5176 /// Performs template instantiation for all implicit template
5177 /// instantiations we have seen until this point.
5178 void Sema::PerformPendingInstantiations(bool LocalOnly) {
5179 while (!PendingLocalImplicitInstantiations.empty() ||
5180 (!LocalOnly && !PendingInstantiations.empty())) {
5181 PendingImplicitInstantiation Inst;
5183 if (PendingLocalImplicitInstantiations.empty()) {
5184 Inst = PendingInstantiations.front();
5185 PendingInstantiations.pop_front();
5187 Inst = PendingLocalImplicitInstantiations.front();
5188 PendingLocalImplicitInstantiations.pop_front();
5191 // Instantiate function definitions
5192 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
5193 bool DefinitionRequired = Function->getTemplateSpecializationKind() ==
5194 TSK_ExplicitInstantiationDefinition;
5195 if (Function->isMultiVersion()) {
5196 getASTContext().forEachMultiversionedFunctionVersion(
5197 Function, [this, Inst, DefinitionRequired](FunctionDecl *CurFD) {
5198 InstantiateFunctionDefinition(/*FIXME:*/ Inst.second, CurFD, true,
5199 DefinitionRequired, true);
5200 if (CurFD->isDefined())
5201 CurFD->setInstantiationIsPending(false);
5204 InstantiateFunctionDefinition(/*FIXME:*/ Inst.second, Function, true,
5205 DefinitionRequired, true);
5206 if (Function->isDefined())
5207 Function->setInstantiationIsPending(false);
5212 // Instantiate variable definitions
5213 VarDecl *Var = cast<VarDecl>(Inst.first);
5215 assert((Var->isStaticDataMember() ||
5216 isa<VarTemplateSpecializationDecl>(Var)) &&
5217 "Not a static data member, nor a variable template"
5218 " specialization?");
5220 // Don't try to instantiate declarations if the most recent redeclaration
5222 if (Var->getMostRecentDecl()->isInvalidDecl())
5225 // Check if the most recent declaration has changed the specialization kind
5226 // and removed the need for implicit instantiation.
5227 switch (Var->getMostRecentDecl()->getTemplateSpecializationKind()) {
5228 case TSK_Undeclared:
5229 llvm_unreachable("Cannot instantitiate an undeclared specialization.");
5230 case TSK_ExplicitInstantiationDeclaration:
5231 case TSK_ExplicitSpecialization:
5232 continue; // No longer need to instantiate this type.
5233 case TSK_ExplicitInstantiationDefinition:
5234 // We only need an instantiation if the pending instantiation *is* the
5235 // explicit instantiation.
5236 if (Var != Var->getMostRecentDecl())
5239 case TSK_ImplicitInstantiation:
5243 PrettyDeclStackTraceEntry CrashInfo(Context, Var, SourceLocation(),
5244 "instantiating variable definition");
5245 bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
5246 TSK_ExplicitInstantiationDefinition;
5248 // Instantiate static data member definitions or variable template
5250 InstantiateVariableDefinition(/*FIXME:*/ Inst.second, Var, true,
5251 DefinitionRequired, true);
5255 void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
5256 const MultiLevelTemplateArgumentList &TemplateArgs) {
5257 for (auto DD : Pattern->ddiags()) {
5258 switch (DD->getKind()) {
5259 case DependentDiagnostic::Access:
5260 HandleDependentAccessCheck(*DD, TemplateArgs);