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/TypeLoc.h"
22 #include "clang/Sema/Initialization.h"
23 #include "clang/Sema/Lookup.h"
24 #include "clang/Sema/PrettyDeclStackTrace.h"
25 #include "clang/Sema/Template.h"
27 using namespace clang;
29 static bool isDeclWithinFunction(const Decl *D) {
30 const DeclContext *DC = D->getDeclContext();
31 if (DC->isFunctionOrMethod())
35 return cast<CXXRecordDecl>(DC)->isLocalClass();
40 template<typename DeclT>
41 static bool SubstQualifier(Sema &SemaRef, const DeclT *OldDecl, DeclT *NewDecl,
42 const MultiLevelTemplateArgumentList &TemplateArgs) {
43 if (!OldDecl->getQualifierLoc())
46 assert((NewDecl->getFriendObjectKind() ||
47 !OldDecl->getLexicalDeclContext()->isDependentContext()) &&
48 "non-friend with qualified name defined in dependent context");
49 Sema::ContextRAII SavedContext(
51 const_cast<DeclContext *>(NewDecl->getFriendObjectKind()
52 ? NewDecl->getLexicalDeclContext()
53 : OldDecl->getLexicalDeclContext()));
55 NestedNameSpecifierLoc NewQualifierLoc
56 = SemaRef.SubstNestedNameSpecifierLoc(OldDecl->getQualifierLoc(),
62 NewDecl->setQualifierInfo(NewQualifierLoc);
66 bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
67 DeclaratorDecl *NewDecl) {
68 return ::SubstQualifier(SemaRef, OldDecl, NewDecl, TemplateArgs);
71 bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
73 return ::SubstQualifier(SemaRef, OldDecl, NewDecl, TemplateArgs);
76 // Include attribute instantiation code.
77 #include "clang/Sema/AttrTemplateInstantiate.inc"
79 static void instantiateDependentAlignedAttr(
80 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
81 const AlignedAttr *Aligned, Decl *New, bool IsPackExpansion) {
82 if (Aligned->isAlignmentExpr()) {
83 // The alignment expression is a constant expression.
84 EnterExpressionEvaluationContext Unevaluated(
85 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
86 ExprResult Result = S.SubstExpr(Aligned->getAlignmentExpr(), TemplateArgs);
87 if (!Result.isInvalid())
88 S.AddAlignedAttr(Aligned->getLocation(), New, Result.getAs<Expr>(),
89 Aligned->getSpellingListIndex(), IsPackExpansion);
91 TypeSourceInfo *Result = S.SubstType(Aligned->getAlignmentType(),
92 TemplateArgs, Aligned->getLocation(),
95 S.AddAlignedAttr(Aligned->getLocation(), New, Result,
96 Aligned->getSpellingListIndex(), IsPackExpansion);
100 static void instantiateDependentAlignedAttr(
101 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
102 const AlignedAttr *Aligned, Decl *New) {
103 if (!Aligned->isPackExpansion()) {
104 instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
108 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
109 if (Aligned->isAlignmentExpr())
110 S.collectUnexpandedParameterPacks(Aligned->getAlignmentExpr(),
113 S.collectUnexpandedParameterPacks(Aligned->getAlignmentType()->getTypeLoc(),
115 assert(!Unexpanded.empty() && "Pack expansion without parameter packs?");
117 // Determine whether we can expand this attribute pack yet.
118 bool Expand = true, RetainExpansion = false;
119 Optional<unsigned> NumExpansions;
120 // FIXME: Use the actual location of the ellipsis.
121 SourceLocation EllipsisLoc = Aligned->getLocation();
122 if (S.CheckParameterPacksForExpansion(EllipsisLoc, Aligned->getRange(),
123 Unexpanded, TemplateArgs, Expand,
124 RetainExpansion, NumExpansions))
128 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, -1);
129 instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, true);
131 for (unsigned I = 0; I != *NumExpansions; ++I) {
132 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, I);
133 instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
138 static void instantiateDependentAssumeAlignedAttr(
139 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
140 const AssumeAlignedAttr *Aligned, Decl *New) {
141 // The alignment expression is a constant expression.
142 EnterExpressionEvaluationContext Unevaluated(
143 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
145 Expr *E, *OE = nullptr;
146 ExprResult Result = S.SubstExpr(Aligned->getAlignment(), TemplateArgs);
147 if (Result.isInvalid())
149 E = Result.getAs<Expr>();
151 if (Aligned->getOffset()) {
152 Result = S.SubstExpr(Aligned->getOffset(), TemplateArgs);
153 if (Result.isInvalid())
155 OE = Result.getAs<Expr>();
158 S.AddAssumeAlignedAttr(Aligned->getLocation(), New, E, OE,
159 Aligned->getSpellingListIndex());
162 static void instantiateDependentAlignValueAttr(
163 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
164 const AlignValueAttr *Aligned, Decl *New) {
165 // The alignment expression is a constant expression.
166 EnterExpressionEvaluationContext Unevaluated(
167 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
168 ExprResult Result = S.SubstExpr(Aligned->getAlignment(), TemplateArgs);
169 if (!Result.isInvalid())
170 S.AddAlignValueAttr(Aligned->getLocation(), New, Result.getAs<Expr>(),
171 Aligned->getSpellingListIndex());
174 static void instantiateDependentAllocAlignAttr(
175 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
176 const AllocAlignAttr *Align, Decl *New) {
177 Expr *Param = IntegerLiteral::Create(
178 S.getASTContext(), llvm::APInt(64, Align->getParamIndex()),
179 S.getASTContext().UnsignedLongLongTy, Align->getLocation());
180 S.AddAllocAlignAttr(Align->getLocation(), New, Param,
181 Align->getSpellingListIndex());
184 static Expr *instantiateDependentFunctionAttrCondition(
185 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
186 const Attr *A, Expr *OldCond, const Decl *Tmpl, FunctionDecl *New) {
187 Expr *Cond = nullptr;
189 Sema::ContextRAII SwitchContext(S, New);
190 EnterExpressionEvaluationContext Unevaluated(
191 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
192 ExprResult Result = S.SubstExpr(OldCond, TemplateArgs);
193 if (Result.isInvalid())
195 Cond = Result.getAs<Expr>();
197 if (!Cond->isTypeDependent()) {
198 ExprResult Converted = S.PerformContextuallyConvertToBool(Cond);
199 if (Converted.isInvalid())
201 Cond = Converted.get();
204 SmallVector<PartialDiagnosticAt, 8> Diags;
205 if (OldCond->isValueDependent() && !Cond->isValueDependent() &&
206 !Expr::isPotentialConstantExprUnevaluated(Cond, New, Diags)) {
207 S.Diag(A->getLocation(), diag::err_attr_cond_never_constant_expr) << A;
208 for (const auto &P : Diags)
209 S.Diag(P.first, P.second);
215 static void instantiateDependentEnableIfAttr(
216 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
217 const EnableIfAttr *EIA, const Decl *Tmpl, FunctionDecl *New) {
218 Expr *Cond = instantiateDependentFunctionAttrCondition(
219 S, TemplateArgs, EIA, EIA->getCond(), Tmpl, New);
222 New->addAttr(new (S.getASTContext()) EnableIfAttr(
223 EIA->getLocation(), S.getASTContext(), Cond, EIA->getMessage(),
224 EIA->getSpellingListIndex()));
227 static void instantiateDependentDiagnoseIfAttr(
228 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
229 const DiagnoseIfAttr *DIA, const Decl *Tmpl, FunctionDecl *New) {
230 Expr *Cond = instantiateDependentFunctionAttrCondition(
231 S, TemplateArgs, DIA, DIA->getCond(), Tmpl, New);
234 New->addAttr(new (S.getASTContext()) DiagnoseIfAttr(
235 DIA->getLocation(), S.getASTContext(), Cond, DIA->getMessage(),
236 DIA->getDiagnosticType(), DIA->getArgDependent(), New,
237 DIA->getSpellingListIndex()));
240 // Constructs and adds to New a new instance of CUDALaunchBoundsAttr using
241 // template A as the base and arguments from TemplateArgs.
242 static void instantiateDependentCUDALaunchBoundsAttr(
243 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
244 const CUDALaunchBoundsAttr &Attr, Decl *New) {
245 // The alignment expression is a constant expression.
246 EnterExpressionEvaluationContext Unevaluated(
247 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
249 ExprResult Result = S.SubstExpr(Attr.getMaxThreads(), TemplateArgs);
250 if (Result.isInvalid())
252 Expr *MaxThreads = Result.getAs<Expr>();
254 Expr *MinBlocks = nullptr;
255 if (Attr.getMinBlocks()) {
256 Result = S.SubstExpr(Attr.getMinBlocks(), TemplateArgs);
257 if (Result.isInvalid())
259 MinBlocks = Result.getAs<Expr>();
262 S.AddLaunchBoundsAttr(Attr.getLocation(), New, MaxThreads, MinBlocks,
263 Attr.getSpellingListIndex());
267 instantiateDependentModeAttr(Sema &S,
268 const MultiLevelTemplateArgumentList &TemplateArgs,
269 const ModeAttr &Attr, Decl *New) {
270 S.AddModeAttr(Attr.getRange(), New, Attr.getMode(),
271 Attr.getSpellingListIndex(), /*InInstantiation=*/true);
274 /// Instantiation of 'declare simd' attribute and its arguments.
275 static void instantiateOMPDeclareSimdDeclAttr(
276 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
277 const OMPDeclareSimdDeclAttr &Attr, Decl *New) {
278 // Allow 'this' in clauses with varlists.
279 if (auto *FTD = dyn_cast<FunctionTemplateDecl>(New))
280 New = FTD->getTemplatedDecl();
281 auto *FD = cast<FunctionDecl>(New);
282 auto *ThisContext = dyn_cast_or_null<CXXRecordDecl>(FD->getDeclContext());
283 SmallVector<Expr *, 4> Uniforms, Aligneds, Alignments, Linears, Steps;
284 SmallVector<unsigned, 4> LinModifiers;
286 auto &&Subst = [&](Expr *E) -> ExprResult {
287 if (auto *DRE = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()))
288 if (auto *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl())) {
289 Sema::ContextRAII SavedContext(S, FD);
290 LocalInstantiationScope Local(S);
291 if (FD->getNumParams() > PVD->getFunctionScopeIndex())
292 Local.InstantiatedLocal(
293 PVD, FD->getParamDecl(PVD->getFunctionScopeIndex()));
294 return S.SubstExpr(E, TemplateArgs);
296 Sema::CXXThisScopeRAII ThisScope(S, ThisContext, /*TypeQuals=*/0,
297 FD->isCXXInstanceMember());
298 return S.SubstExpr(E, TemplateArgs);
302 if (auto *E = Attr.getSimdlen())
305 if (Attr.uniforms_size() > 0) {
306 for(auto *E : Attr.uniforms()) {
307 ExprResult Inst = Subst(E);
308 if (Inst.isInvalid())
310 Uniforms.push_back(Inst.get());
314 auto AI = Attr.alignments_begin();
315 for (auto *E : Attr.aligneds()) {
316 ExprResult Inst = Subst(E);
317 if (Inst.isInvalid())
319 Aligneds.push_back(Inst.get());
322 Inst = S.SubstExpr(*AI, TemplateArgs);
323 Alignments.push_back(Inst.get());
327 auto SI = Attr.steps_begin();
328 for (auto *E : Attr.linears()) {
329 ExprResult Inst = Subst(E);
330 if (Inst.isInvalid())
332 Linears.push_back(Inst.get());
335 Inst = S.SubstExpr(*SI, TemplateArgs);
336 Steps.push_back(Inst.get());
339 LinModifiers.append(Attr.modifiers_begin(), Attr.modifiers_end());
340 (void)S.ActOnOpenMPDeclareSimdDirective(
341 S.ConvertDeclToDeclGroup(New), Attr.getBranchState(), Simdlen.get(),
342 Uniforms, Aligneds, Alignments, Linears, LinModifiers, Steps,
346 static bool DeclContainsAttr(const Decl *D, const Attr *NewAttr) {
347 if (!D->hasAttrs() || NewAttr->duplicatesAllowed())
349 return llvm::find_if(D->getAttrs(), [NewAttr](const Attr *Attr) {
350 return Attr->getKind() == NewAttr->getKind();
351 }) != D->getAttrs().end();
354 void Sema::InstantiateAttrsForDecl(
355 const MultiLevelTemplateArgumentList &TemplateArgs, const Decl *Tmpl,
356 Decl *New, LateInstantiatedAttrVec *LateAttrs,
357 LocalInstantiationScope *OuterMostScope) {
358 if (NamedDecl *ND = dyn_cast<NamedDecl>(New)) {
359 for (const auto *TmplAttr : Tmpl->attrs()) {
360 // FIXME: If any of the special case versions from InstantiateAttrs become
361 // applicable to template declaration, we'll need to add them here.
362 CXXThisScopeRAII ThisScope(
363 *this, dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext()),
364 /*TypeQuals*/ 0, ND->isCXXInstanceMember());
366 Attr *NewAttr = sema::instantiateTemplateAttributeForDecl(
367 TmplAttr, Context, *this, TemplateArgs);
368 if (NewAttr && !DeclContainsAttr(New, NewAttr))
369 New->addAttr(NewAttr);
374 void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
375 const Decl *Tmpl, Decl *New,
376 LateInstantiatedAttrVec *LateAttrs,
377 LocalInstantiationScope *OuterMostScope) {
378 for (const auto *TmplAttr : Tmpl->attrs()) {
379 // FIXME: This should be generalized to more than just the AlignedAttr.
380 const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr);
381 if (Aligned && Aligned->isAlignmentDependent()) {
382 instantiateDependentAlignedAttr(*this, TemplateArgs, Aligned, New);
386 const AssumeAlignedAttr *AssumeAligned = dyn_cast<AssumeAlignedAttr>(TmplAttr);
388 instantiateDependentAssumeAlignedAttr(*this, TemplateArgs, AssumeAligned, New);
392 const AlignValueAttr *AlignValue = dyn_cast<AlignValueAttr>(TmplAttr);
394 instantiateDependentAlignValueAttr(*this, TemplateArgs, AlignValue, New);
398 if (const auto *AllocAlign = dyn_cast<AllocAlignAttr>(TmplAttr)) {
399 instantiateDependentAllocAlignAttr(*this, TemplateArgs, AllocAlign, New);
404 if (const auto *EnableIf = dyn_cast<EnableIfAttr>(TmplAttr)) {
405 instantiateDependentEnableIfAttr(*this, TemplateArgs, EnableIf, Tmpl,
406 cast<FunctionDecl>(New));
410 if (const auto *DiagnoseIf = dyn_cast<DiagnoseIfAttr>(TmplAttr)) {
411 instantiateDependentDiagnoseIfAttr(*this, TemplateArgs, DiagnoseIf, Tmpl,
412 cast<FunctionDecl>(New));
416 if (const CUDALaunchBoundsAttr *CUDALaunchBounds =
417 dyn_cast<CUDALaunchBoundsAttr>(TmplAttr)) {
418 instantiateDependentCUDALaunchBoundsAttr(*this, TemplateArgs,
419 *CUDALaunchBounds, New);
423 if (const ModeAttr *Mode = dyn_cast<ModeAttr>(TmplAttr)) {
424 instantiateDependentModeAttr(*this, TemplateArgs, *Mode, New);
428 if (const auto *OMPAttr = dyn_cast<OMPDeclareSimdDeclAttr>(TmplAttr)) {
429 instantiateOMPDeclareSimdDeclAttr(*this, TemplateArgs, *OMPAttr, New);
433 // Existing DLL attribute on the instantiation takes precedence.
434 if (TmplAttr->getKind() == attr::DLLExport ||
435 TmplAttr->getKind() == attr::DLLImport) {
436 if (New->hasAttr<DLLExportAttr>() || New->hasAttr<DLLImportAttr>()) {
441 if (auto ABIAttr = dyn_cast<ParameterABIAttr>(TmplAttr)) {
442 AddParameterABIAttr(ABIAttr->getRange(), New, ABIAttr->getABI(),
443 ABIAttr->getSpellingListIndex());
447 if (isa<NSConsumedAttr>(TmplAttr) || isa<CFConsumedAttr>(TmplAttr)) {
448 AddNSConsumedAttr(TmplAttr->getRange(), New,
449 TmplAttr->getSpellingListIndex(),
450 isa<NSConsumedAttr>(TmplAttr),
451 /*template instantiation*/ true);
455 assert(!TmplAttr->isPackExpansion());
456 if (TmplAttr->isLateParsed() && LateAttrs) {
457 // Late parsed attributes must be instantiated and attached after the
458 // enclosing class has been instantiated. See Sema::InstantiateClass.
459 LocalInstantiationScope *Saved = nullptr;
460 if (CurrentInstantiationScope)
461 Saved = CurrentInstantiationScope->cloneScopes(OuterMostScope);
462 LateAttrs->push_back(LateInstantiatedAttribute(TmplAttr, Saved, New));
464 // Allow 'this' within late-parsed attributes.
465 NamedDecl *ND = dyn_cast<NamedDecl>(New);
466 CXXRecordDecl *ThisContext =
467 dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext());
468 CXXThisScopeRAII ThisScope(*this, ThisContext, /*TypeQuals*/0,
469 ND && ND->isCXXInstanceMember());
471 Attr *NewAttr = sema::instantiateTemplateAttribute(TmplAttr, Context,
472 *this, TemplateArgs);
474 if (NewAttr && !DeclContainsAttr(New, NewAttr))
475 New->addAttr(NewAttr);
480 /// Get the previous declaration of a declaration for the purposes of template
481 /// instantiation. If this finds a previous declaration, then the previous
482 /// declaration of the instantiation of D should be an instantiation of the
483 /// result of this function.
484 template<typename DeclT>
485 static DeclT *getPreviousDeclForInstantiation(DeclT *D) {
486 DeclT *Result = D->getPreviousDecl();
488 // If the declaration is within a class, and the previous declaration was
489 // merged from a different definition of that class, then we don't have a
490 // previous declaration for the purpose of template instantiation.
491 if (Result && isa<CXXRecordDecl>(D->getDeclContext()) &&
492 D->getLexicalDeclContext() != Result->getLexicalDeclContext())
499 TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
500 llvm_unreachable("Translation units cannot be instantiated");
504 TemplateDeclInstantiator::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
505 llvm_unreachable("pragma comment cannot be instantiated");
508 Decl *TemplateDeclInstantiator::VisitPragmaDetectMismatchDecl(
509 PragmaDetectMismatchDecl *D) {
510 llvm_unreachable("pragma comment cannot be instantiated");
514 TemplateDeclInstantiator::VisitExternCContextDecl(ExternCContextDecl *D) {
515 llvm_unreachable("extern \"C\" context cannot be instantiated");
519 TemplateDeclInstantiator::VisitLabelDecl(LabelDecl *D) {
520 LabelDecl *Inst = LabelDecl::Create(SemaRef.Context, Owner, D->getLocation(),
522 Owner->addDecl(Inst);
527 TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
528 llvm_unreachable("Namespaces cannot be instantiated");
532 TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
533 NamespaceAliasDecl *Inst
534 = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
535 D->getNamespaceLoc(),
538 D->getQualifierLoc(),
539 D->getTargetNameLoc(),
541 Owner->addDecl(Inst);
545 Decl *TemplateDeclInstantiator::InstantiateTypedefNameDecl(TypedefNameDecl *D,
547 bool Invalid = false;
548 TypeSourceInfo *DI = D->getTypeSourceInfo();
549 if (DI->getType()->isInstantiationDependentType() ||
550 DI->getType()->isVariablyModifiedType()) {
551 DI = SemaRef.SubstType(DI, TemplateArgs,
552 D->getLocation(), D->getDeclName());
555 DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
558 SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
561 // HACK: g++ has a bug where it gets the value kind of ?: wrong.
562 // libstdc++ relies upon this bug in its implementation of common_type.
563 // If we happen to be processing that implementation, fake up the g++ ?:
564 // semantics. See LWG issue 2141 for more information on the bug.
565 const DecltypeType *DT = DI->getType()->getAs<DecltypeType>();
566 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D->getDeclContext());
567 if (DT && RD && isa<ConditionalOperator>(DT->getUnderlyingExpr()) &&
568 DT->isReferenceType() &&
569 RD->getEnclosingNamespaceContext() == SemaRef.getStdNamespace() &&
570 RD->getIdentifier() && RD->getIdentifier()->isStr("common_type") &&
571 D->getIdentifier() && D->getIdentifier()->isStr("type") &&
572 SemaRef.getSourceManager().isInSystemHeader(D->getLocStart()))
573 // Fold it to the (non-reference) type which g++ would have produced.
574 DI = SemaRef.Context.getTrivialTypeSourceInfo(
575 DI->getType().getNonReferenceType());
577 // Create the new typedef
578 TypedefNameDecl *Typedef;
580 Typedef = TypeAliasDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
581 D->getLocation(), D->getIdentifier(), DI);
583 Typedef = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
584 D->getLocation(), D->getIdentifier(), DI);
586 Typedef->setInvalidDecl();
588 // If the old typedef was the name for linkage purposes of an anonymous
589 // tag decl, re-establish that relationship for the new typedef.
590 if (const TagType *oldTagType = D->getUnderlyingType()->getAs<TagType>()) {
591 TagDecl *oldTag = oldTagType->getDecl();
592 if (oldTag->getTypedefNameForAnonDecl() == D && !Invalid) {
593 TagDecl *newTag = DI->getType()->castAs<TagType>()->getDecl();
594 assert(!newTag->hasNameForLinkage());
595 newTag->setTypedefNameForAnonDecl(Typedef);
599 if (TypedefNameDecl *Prev = getPreviousDeclForInstantiation(D)) {
600 NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
605 TypedefNameDecl *InstPrevTypedef = cast<TypedefNameDecl>(InstPrev);
607 // If the typedef types are not identical, reject them.
608 SemaRef.isIncompatibleTypedef(InstPrevTypedef, Typedef);
610 Typedef->setPreviousDecl(InstPrevTypedef);
613 SemaRef.InstantiateAttrs(TemplateArgs, D, Typedef);
615 Typedef->setAccess(D->getAccess());
620 Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
621 Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/false);
623 Owner->addDecl(Typedef);
627 Decl *TemplateDeclInstantiator::VisitTypeAliasDecl(TypeAliasDecl *D) {
628 Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/true);
630 Owner->addDecl(Typedef);
635 TemplateDeclInstantiator::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
636 // Create a local instantiation scope for this type alias template, which
637 // will contain the instantiations of the template parameters.
638 LocalInstantiationScope Scope(SemaRef);
640 TemplateParameterList *TempParams = D->getTemplateParameters();
641 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
645 TypeAliasDecl *Pattern = D->getTemplatedDecl();
647 TypeAliasTemplateDecl *PrevAliasTemplate = nullptr;
648 if (getPreviousDeclForInstantiation<TypedefNameDecl>(Pattern)) {
649 DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
650 if (!Found.empty()) {
651 PrevAliasTemplate = dyn_cast<TypeAliasTemplateDecl>(Found.front());
655 TypeAliasDecl *AliasInst = cast_or_null<TypeAliasDecl>(
656 InstantiateTypedefNameDecl(Pattern, /*IsTypeAlias=*/true));
660 TypeAliasTemplateDecl *Inst
661 = TypeAliasTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
662 D->getDeclName(), InstParams, AliasInst);
663 AliasInst->setDescribedAliasTemplate(Inst);
664 if (PrevAliasTemplate)
665 Inst->setPreviousDecl(PrevAliasTemplate);
667 Inst->setAccess(D->getAccess());
669 if (!PrevAliasTemplate)
670 Inst->setInstantiatedFromMemberTemplate(D);
672 Owner->addDecl(Inst);
677 Decl *TemplateDeclInstantiator::VisitBindingDecl(BindingDecl *D) {
678 auto *NewBD = BindingDecl::Create(SemaRef.Context, Owner, D->getLocation(),
680 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewBD);
684 Decl *TemplateDeclInstantiator::VisitDecompositionDecl(DecompositionDecl *D) {
685 // Transform the bindings first.
686 SmallVector<BindingDecl*, 16> NewBindings;
687 for (auto *OldBD : D->bindings())
688 NewBindings.push_back(cast<BindingDecl>(VisitBindingDecl(OldBD)));
689 ArrayRef<BindingDecl*> NewBindingArray = NewBindings;
691 auto *NewDD = cast_or_null<DecompositionDecl>(
692 VisitVarDecl(D, /*InstantiatingVarTemplate=*/false, &NewBindingArray));
694 if (!NewDD || NewDD->isInvalidDecl())
695 for (auto *NewBD : NewBindings)
696 NewBD->setInvalidDecl();
701 Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
702 return VisitVarDecl(D, /*InstantiatingVarTemplate=*/false);
705 Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D,
706 bool InstantiatingVarTemplate,
707 ArrayRef<BindingDecl*> *Bindings) {
709 // Do substitution on the type of the declaration
710 TypeSourceInfo *DI = SemaRef.SubstType(
711 D->getTypeSourceInfo(), TemplateArgs, D->getTypeSpecStartLoc(),
712 D->getDeclName(), /*AllowDeducedTST*/true);
716 if (DI->getType()->isFunctionType()) {
717 SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
718 << D->isStaticDataMember() << DI->getType();
722 DeclContext *DC = Owner;
723 if (D->isLocalExternDecl())
724 SemaRef.adjustContextForLocalExternDecl(DC);
726 // Build the instantiated declaration.
729 Var = DecompositionDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
730 D->getLocation(), DI->getType(), DI,
731 D->getStorageClass(), *Bindings);
733 Var = VarDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
734 D->getLocation(), D->getIdentifier(), DI->getType(),
735 DI, D->getStorageClass());
737 // In ARC, infer 'retaining' for variables of retainable type.
738 if (SemaRef.getLangOpts().ObjCAutoRefCount &&
739 SemaRef.inferObjCARCLifetime(Var))
740 Var->setInvalidDecl();
742 // Substitute the nested name specifier, if any.
743 if (SubstQualifier(D, Var))
746 SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs, Owner,
747 StartingScope, InstantiatingVarTemplate);
749 if (D->isNRVOVariable()) {
750 QualType ReturnType = cast<FunctionDecl>(DC)->getReturnType();
751 if (SemaRef.isCopyElisionCandidate(ReturnType, Var, false))
752 Var->setNRVOVariable(true);
755 Var->setImplicit(D->isImplicit());
760 Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
762 = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
763 D->getAccessSpecifierLoc(), D->getColonLoc());
764 Owner->addHiddenDecl(AD);
768 Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
769 bool Invalid = false;
770 TypeSourceInfo *DI = D->getTypeSourceInfo();
771 if (DI->getType()->isInstantiationDependentType() ||
772 DI->getType()->isVariablyModifiedType()) {
773 DI = SemaRef.SubstType(DI, TemplateArgs,
774 D->getLocation(), D->getDeclName());
776 DI = D->getTypeSourceInfo();
778 } else if (DI->getType()->isFunctionType()) {
779 // C++ [temp.arg.type]p3:
780 // If a declaration acquires a function type through a type
781 // dependent on a template-parameter and this causes a
782 // declaration that does not use the syntactic form of a
783 // function declarator to have function type, the program is
785 SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
790 SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
793 Expr *BitWidth = D->getBitWidth();
797 // The bit-width expression is a constant expression.
798 EnterExpressionEvaluationContext Unevaluated(
799 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
801 ExprResult InstantiatedBitWidth
802 = SemaRef.SubstExpr(BitWidth, TemplateArgs);
803 if (InstantiatedBitWidth.isInvalid()) {
807 BitWidth = InstantiatedBitWidth.getAs<Expr>();
810 FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
812 cast<RecordDecl>(Owner),
816 D->getInClassInitStyle(),
817 D->getInnerLocStart(),
821 cast<Decl>(Owner)->setInvalidDecl();
825 SemaRef.InstantiateAttrs(TemplateArgs, D, Field, LateAttrs, StartingScope);
827 if (Field->hasAttrs())
828 SemaRef.CheckAlignasUnderalignment(Field);
831 Field->setInvalidDecl();
833 if (!Field->getDeclName()) {
834 // Keep track of where this decl came from.
835 SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
837 if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
838 if (Parent->isAnonymousStructOrUnion() &&
839 Parent->getRedeclContext()->isFunctionOrMethod())
840 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
843 Field->setImplicit(D->isImplicit());
844 Field->setAccess(D->getAccess());
845 Owner->addDecl(Field);
850 Decl *TemplateDeclInstantiator::VisitMSPropertyDecl(MSPropertyDecl *D) {
851 bool Invalid = false;
852 TypeSourceInfo *DI = D->getTypeSourceInfo();
854 if (DI->getType()->isVariablyModifiedType()) {
855 SemaRef.Diag(D->getLocation(), diag::err_property_is_variably_modified)
858 } else if (DI->getType()->isInstantiationDependentType()) {
859 DI = SemaRef.SubstType(DI, TemplateArgs,
860 D->getLocation(), D->getDeclName());
862 DI = D->getTypeSourceInfo();
864 } else if (DI->getType()->isFunctionType()) {
865 // C++ [temp.arg.type]p3:
866 // If a declaration acquires a function type through a type
867 // dependent on a template-parameter and this causes a
868 // declaration that does not use the syntactic form of a
869 // function declarator to have function type, the program is
871 SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
876 SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
879 MSPropertyDecl *Property = MSPropertyDecl::Create(
880 SemaRef.Context, Owner, D->getLocation(), D->getDeclName(), DI->getType(),
881 DI, D->getLocStart(), D->getGetterId(), D->getSetterId());
883 SemaRef.InstantiateAttrs(TemplateArgs, D, Property, LateAttrs,
887 Property->setInvalidDecl();
889 Property->setAccess(D->getAccess());
890 Owner->addDecl(Property);
895 Decl *TemplateDeclInstantiator::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
896 NamedDecl **NamedChain =
897 new (SemaRef.Context)NamedDecl*[D->getChainingSize()];
900 for (auto *PI : D->chain()) {
901 NamedDecl *Next = SemaRef.FindInstantiatedDecl(D->getLocation(), PI,
906 NamedChain[i++] = Next;
909 QualType T = cast<FieldDecl>(NamedChain[i-1])->getType();
910 IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
911 SemaRef.Context, Owner, D->getLocation(), D->getIdentifier(), T,
912 {NamedChain, D->getChainingSize()});
914 for (const auto *Attr : D->attrs())
915 IndirectField->addAttr(Attr->clone(SemaRef.Context));
917 IndirectField->setImplicit(D->isImplicit());
918 IndirectField->setAccess(D->getAccess());
919 Owner->addDecl(IndirectField);
920 return IndirectField;
923 Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
924 // Handle friend type expressions by simply substituting template
925 // parameters into the pattern type and checking the result.
926 if (TypeSourceInfo *Ty = D->getFriendType()) {
927 TypeSourceInfo *InstTy;
928 // If this is an unsupported friend, don't bother substituting template
929 // arguments into it. The actual type referred to won't be used by any
930 // parts of Clang, and may not be valid for instantiating. Just use the
931 // same info for the instantiated friend.
932 if (D->isUnsupportedFriend()) {
935 InstTy = SemaRef.SubstType(Ty, TemplateArgs,
936 D->getLocation(), DeclarationName());
941 FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getLocStart(),
942 D->getFriendLoc(), InstTy);
946 FD->setAccess(AS_public);
947 FD->setUnsupportedFriend(D->isUnsupportedFriend());
952 NamedDecl *ND = D->getFriendDecl();
953 assert(ND && "friend decl must be a decl or a type!");
955 // All of the Visit implementations for the various potential friend
956 // declarations have to be carefully written to work for friend
957 // objects, with the most important detail being that the target
958 // decl should almost certainly not be placed in Owner.
959 Decl *NewND = Visit(ND);
960 if (!NewND) return nullptr;
963 FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
964 cast<NamedDecl>(NewND), D->getFriendLoc());
965 FD->setAccess(AS_public);
966 FD->setUnsupportedFriend(D->isUnsupportedFriend());
971 Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
972 Expr *AssertExpr = D->getAssertExpr();
974 // The expression in a static assertion is a constant expression.
975 EnterExpressionEvaluationContext Unevaluated(
976 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
978 ExprResult InstantiatedAssertExpr
979 = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
980 if (InstantiatedAssertExpr.isInvalid())
983 return SemaRef.BuildStaticAssertDeclaration(D->getLocation(),
984 InstantiatedAssertExpr.get(),
990 Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
991 EnumDecl *PrevDecl = nullptr;
992 if (EnumDecl *PatternPrev = getPreviousDeclForInstantiation(D)) {
993 NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
996 if (!Prev) return nullptr;
997 PrevDecl = cast<EnumDecl>(Prev);
1000 EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
1001 D->getLocation(), D->getIdentifier(),
1002 PrevDecl, D->isScoped(),
1003 D->isScopedUsingClassTag(), D->isFixed());
1005 if (TypeSourceInfo *TI = D->getIntegerTypeSourceInfo()) {
1006 // If we have type source information for the underlying type, it means it
1007 // has been explicitly set by the user. Perform substitution on it before
1009 SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
1010 TypeSourceInfo *NewTI = SemaRef.SubstType(TI, TemplateArgs, UnderlyingLoc,
1012 if (!NewTI || SemaRef.CheckEnumUnderlyingType(NewTI))
1013 Enum->setIntegerType(SemaRef.Context.IntTy);
1015 Enum->setIntegerTypeSourceInfo(NewTI);
1017 assert(!D->getIntegerType()->isDependentType()
1018 && "Dependent type without type source info");
1019 Enum->setIntegerType(D->getIntegerType());
1023 SemaRef.InstantiateAttrs(TemplateArgs, D, Enum);
1025 Enum->setInstantiationOfMemberEnum(D, TSK_ImplicitInstantiation);
1026 Enum->setAccess(D->getAccess());
1027 // Forward the mangling number from the template to the instantiated decl.
1028 SemaRef.Context.setManglingNumber(Enum, SemaRef.Context.getManglingNumber(D));
1029 // See if the old tag was defined along with a declarator.
1030 // If it did, mark the new tag as being associated with that declarator.
1031 if (DeclaratorDecl *DD = SemaRef.Context.getDeclaratorForUnnamedTagDecl(D))
1032 SemaRef.Context.addDeclaratorForUnnamedTagDecl(Enum, DD);
1033 // See if the old tag was defined along with a typedef.
1034 // If it did, mark the new tag as being associated with that typedef.
1035 if (TypedefNameDecl *TND = SemaRef.Context.getTypedefNameForUnnamedTagDecl(D))
1036 SemaRef.Context.addTypedefNameForUnnamedTagDecl(Enum, TND);
1037 if (SubstQualifier(D, Enum)) return nullptr;
1038 Owner->addDecl(Enum);
1040 EnumDecl *Def = D->getDefinition();
1041 if (Def && Def != D) {
1042 // If this is an out-of-line definition of an enum member template, check
1043 // that the underlying types match in the instantiation of both
1045 if (TypeSourceInfo *TI = Def->getIntegerTypeSourceInfo()) {
1046 SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
1047 QualType DefnUnderlying =
1048 SemaRef.SubstType(TI->getType(), TemplateArgs,
1049 UnderlyingLoc, DeclarationName());
1050 SemaRef.CheckEnumRedeclaration(Def->getLocation(), Def->isScoped(),
1052 /*EnumUnderlyingIsImplicit=*/false, Enum);
1056 // C++11 [temp.inst]p1: The implicit instantiation of a class template
1057 // specialization causes the implicit instantiation of the declarations, but
1058 // not the definitions of scoped member enumerations.
1060 // DR1484 clarifies that enumeration definitions inside of a template
1061 // declaration aren't considered entities that can be separately instantiated
1062 // from the rest of the entity they are declared inside of.
1063 if (isDeclWithinFunction(D) ? D == Def : Def && !Enum->isScoped()) {
1064 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
1065 InstantiateEnumDefinition(Enum, Def);
1071 void TemplateDeclInstantiator::InstantiateEnumDefinition(
1072 EnumDecl *Enum, EnumDecl *Pattern) {
1073 Enum->startDefinition();
1075 // Update the location to refer to the definition.
1076 Enum->setLocation(Pattern->getLocation());
1078 SmallVector<Decl*, 4> Enumerators;
1080 EnumConstantDecl *LastEnumConst = nullptr;
1081 for (auto *EC : Pattern->enumerators()) {
1082 // The specified value for the enumerator.
1083 ExprResult Value((Expr *)nullptr);
1084 if (Expr *UninstValue = EC->getInitExpr()) {
1085 // The enumerator's value expression is a constant expression.
1086 EnterExpressionEvaluationContext Unevaluated(
1087 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
1089 Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
1092 // Drop the initial value and continue.
1093 bool isInvalid = false;
1094 if (Value.isInvalid()) {
1099 EnumConstantDecl *EnumConst
1100 = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
1101 EC->getLocation(), EC->getIdentifier(),
1106 EnumConst->setInvalidDecl();
1107 Enum->setInvalidDecl();
1111 SemaRef.InstantiateAttrs(TemplateArgs, EC, EnumConst);
1113 EnumConst->setAccess(Enum->getAccess());
1114 Enum->addDecl(EnumConst);
1115 Enumerators.push_back(EnumConst);
1116 LastEnumConst = EnumConst;
1118 if (Pattern->getDeclContext()->isFunctionOrMethod() &&
1119 !Enum->isScoped()) {
1120 // If the enumeration is within a function or method, record the enum
1121 // constant as a local.
1122 SemaRef.CurrentInstantiationScope->InstantiatedLocal(EC, EnumConst);
1127 SemaRef.ActOnEnumBody(Enum->getLocation(), Enum->getBraceRange(), Enum,
1132 Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
1133 llvm_unreachable("EnumConstantDecls can only occur within EnumDecls.");
1137 TemplateDeclInstantiator::VisitBuiltinTemplateDecl(BuiltinTemplateDecl *D) {
1138 llvm_unreachable("BuiltinTemplateDecls cannot be instantiated.");
1141 Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1142 bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1144 // Create a local instantiation scope for this class template, which
1145 // will contain the instantiations of the template parameters.
1146 LocalInstantiationScope Scope(SemaRef);
1147 TemplateParameterList *TempParams = D->getTemplateParameters();
1148 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1152 CXXRecordDecl *Pattern = D->getTemplatedDecl();
1154 // Instantiate the qualifier. We have to do this first in case
1155 // we're a friend declaration, because if we are then we need to put
1156 // the new declaration in the appropriate context.
1157 NestedNameSpecifierLoc QualifierLoc = Pattern->getQualifierLoc();
1159 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1165 CXXRecordDecl *PrevDecl = nullptr;
1166 ClassTemplateDecl *PrevClassTemplate = nullptr;
1168 if (!isFriend && getPreviousDeclForInstantiation(Pattern)) {
1169 DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
1170 if (!Found.empty()) {
1171 PrevClassTemplate = dyn_cast<ClassTemplateDecl>(Found.front());
1172 if (PrevClassTemplate)
1173 PrevDecl = PrevClassTemplate->getTemplatedDecl();
1177 // If this isn't a friend, then it's a member template, in which
1178 // case we just want to build the instantiation in the
1179 // specialization. If it is a friend, we want to build it in
1180 // the appropriate context.
1181 DeclContext *DC = Owner;
1185 SS.Adopt(QualifierLoc);
1186 DC = SemaRef.computeDeclContext(SS);
1187 if (!DC) return nullptr;
1189 DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
1190 Pattern->getDeclContext(),
1194 // Look for a previous declaration of the template in the owning
1196 LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
1197 Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1198 SemaRef.LookupQualifiedName(R, DC);
1200 if (R.isSingleResult()) {
1201 PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
1202 if (PrevClassTemplate)
1203 PrevDecl = PrevClassTemplate->getTemplatedDecl();
1206 if (!PrevClassTemplate && QualifierLoc) {
1207 SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
1208 << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
1209 << QualifierLoc.getSourceRange();
1213 bool AdoptedPreviousTemplateParams = false;
1214 if (PrevClassTemplate) {
1215 bool Complain = true;
1217 // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
1218 // template for struct std::tr1::__detail::_Map_base, where the
1219 // template parameters of the friend declaration don't match the
1220 // template parameters of the original declaration. In this one
1221 // case, we don't complain about the ill-formed friend
1223 if (isFriend && Pattern->getIdentifier() &&
1224 Pattern->getIdentifier()->isStr("_Map_base") &&
1225 DC->isNamespace() &&
1226 cast<NamespaceDecl>(DC)->getIdentifier() &&
1227 cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
1228 DeclContext *DCParent = DC->getParent();
1229 if (DCParent->isNamespace() &&
1230 cast<NamespaceDecl>(DCParent)->getIdentifier() &&
1231 cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
1232 if (cast<Decl>(DCParent)->isInStdNamespace())
1237 TemplateParameterList *PrevParams
1238 = PrevClassTemplate->getTemplateParameters();
1240 // Make sure the parameter lists match.
1241 if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
1243 Sema::TPL_TemplateMatch)) {
1247 AdoptedPreviousTemplateParams = true;
1248 InstParams = PrevParams;
1251 // Do some additional validation, then merge default arguments
1252 // from the existing declarations.
1253 if (!AdoptedPreviousTemplateParams &&
1254 SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
1255 Sema::TPC_ClassTemplate))
1260 CXXRecordDecl *RecordInst
1261 = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
1262 Pattern->getLocStart(), Pattern->getLocation(),
1263 Pattern->getIdentifier(), PrevDecl,
1264 /*DelayTypeCreation=*/true);
1267 RecordInst->setQualifierInfo(QualifierLoc);
1269 ClassTemplateDecl *Inst
1270 = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
1271 D->getIdentifier(), InstParams, RecordInst);
1272 assert(!(isFriend && Owner->isDependentContext()));
1273 Inst->setPreviousDecl(PrevClassTemplate);
1275 RecordInst->setDescribedClassTemplate(Inst);
1278 if (PrevClassTemplate)
1279 Inst->setAccess(PrevClassTemplate->getAccess());
1281 Inst->setAccess(D->getAccess());
1283 Inst->setObjectOfFriendDecl();
1284 // TODO: do we want to track the instantiation progeny of this
1285 // friend target decl?
1287 Inst->setAccess(D->getAccess());
1288 if (!PrevClassTemplate)
1289 Inst->setInstantiatedFromMemberTemplate(D);
1292 // Trigger creation of the type for the instantiation.
1293 SemaRef.Context.getInjectedClassNameType(RecordInst,
1294 Inst->getInjectedClassNameSpecialization());
1296 // Finish handling of friends.
1298 DC->makeDeclVisibleInContext(Inst);
1299 Inst->setLexicalDeclContext(Owner);
1300 RecordInst->setLexicalDeclContext(Owner);
1304 if (D->isOutOfLine()) {
1305 Inst->setLexicalDeclContext(D->getLexicalDeclContext());
1306 RecordInst->setLexicalDeclContext(D->getLexicalDeclContext());
1309 Owner->addDecl(Inst);
1311 if (!PrevClassTemplate) {
1312 // Queue up any out-of-line partial specializations of this member
1313 // class template; the client will force their instantiation once
1314 // the enclosing class has been instantiated.
1315 SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
1316 D->getPartialSpecializations(PartialSpecs);
1317 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
1318 if (PartialSpecs[I]->getFirstDecl()->isOutOfLine())
1319 OutOfLinePartialSpecs.push_back(std::make_pair(Inst, PartialSpecs[I]));
1326 TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
1327 ClassTemplatePartialSpecializationDecl *D) {
1328 ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
1330 // Lookup the already-instantiated declaration in the instantiation
1331 // of the class template and return that.
1332 DeclContext::lookup_result Found
1333 = Owner->lookup(ClassTemplate->getDeclName());
1337 ClassTemplateDecl *InstClassTemplate
1338 = dyn_cast<ClassTemplateDecl>(Found.front());
1339 if (!InstClassTemplate)
1342 if (ClassTemplatePartialSpecializationDecl *Result
1343 = InstClassTemplate->findPartialSpecInstantiatedFromMember(D))
1346 return InstantiateClassTemplatePartialSpecialization(InstClassTemplate, D);
1349 Decl *TemplateDeclInstantiator::VisitVarTemplateDecl(VarTemplateDecl *D) {
1350 assert(D->getTemplatedDecl()->isStaticDataMember() &&
1351 "Only static data member templates are allowed.");
1353 // Create a local instantiation scope for this variable template, which
1354 // will contain the instantiations of the template parameters.
1355 LocalInstantiationScope Scope(SemaRef);
1356 TemplateParameterList *TempParams = D->getTemplateParameters();
1357 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1361 VarDecl *Pattern = D->getTemplatedDecl();
1362 VarTemplateDecl *PrevVarTemplate = nullptr;
1364 if (getPreviousDeclForInstantiation(Pattern)) {
1365 DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
1367 PrevVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
1371 cast_or_null<VarDecl>(VisitVarDecl(Pattern,
1372 /*InstantiatingVarTemplate=*/true));
1373 if (!VarInst) return nullptr;
1375 DeclContext *DC = Owner;
1377 VarTemplateDecl *Inst = VarTemplateDecl::Create(
1378 SemaRef.Context, DC, D->getLocation(), D->getIdentifier(), InstParams,
1380 VarInst->setDescribedVarTemplate(Inst);
1381 Inst->setPreviousDecl(PrevVarTemplate);
1383 Inst->setAccess(D->getAccess());
1384 if (!PrevVarTemplate)
1385 Inst->setInstantiatedFromMemberTemplate(D);
1387 if (D->isOutOfLine()) {
1388 Inst->setLexicalDeclContext(D->getLexicalDeclContext());
1389 VarInst->setLexicalDeclContext(D->getLexicalDeclContext());
1392 Owner->addDecl(Inst);
1394 if (!PrevVarTemplate) {
1395 // Queue up any out-of-line partial specializations of this member
1396 // variable template; the client will force their instantiation once
1397 // the enclosing class has been instantiated.
1398 SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
1399 D->getPartialSpecializations(PartialSpecs);
1400 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
1401 if (PartialSpecs[I]->getFirstDecl()->isOutOfLine())
1402 OutOfLineVarPartialSpecs.push_back(
1403 std::make_pair(Inst, PartialSpecs[I]));
1409 Decl *TemplateDeclInstantiator::VisitVarTemplatePartialSpecializationDecl(
1410 VarTemplatePartialSpecializationDecl *D) {
1411 assert(D->isStaticDataMember() &&
1412 "Only static data member templates are allowed.");
1414 VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
1416 // Lookup the already-instantiated declaration and return that.
1417 DeclContext::lookup_result Found = Owner->lookup(VarTemplate->getDeclName());
1418 assert(!Found.empty() && "Instantiation found nothing?");
1420 VarTemplateDecl *InstVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
1421 assert(InstVarTemplate && "Instantiation did not find a variable template?");
1423 if (VarTemplatePartialSpecializationDecl *Result =
1424 InstVarTemplate->findPartialSpecInstantiatedFromMember(D))
1427 return InstantiateVarTemplatePartialSpecialization(InstVarTemplate, D);
1431 TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1432 // Create a local instantiation scope for this function template, which
1433 // will contain the instantiations of the template parameters and then get
1434 // merged with the local instantiation scope for the function template
1436 LocalInstantiationScope Scope(SemaRef);
1438 TemplateParameterList *TempParams = D->getTemplateParameters();
1439 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1443 FunctionDecl *Instantiated = nullptr;
1444 if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
1445 Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
1448 Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
1449 D->getTemplatedDecl(),
1455 // Link the instantiated function template declaration to the function
1456 // template from which it was instantiated.
1457 FunctionTemplateDecl *InstTemplate
1458 = Instantiated->getDescribedFunctionTemplate();
1459 InstTemplate->setAccess(D->getAccess());
1460 assert(InstTemplate &&
1461 "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
1463 bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
1465 // Link the instantiation back to the pattern *unless* this is a
1466 // non-definition friend declaration.
1467 if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
1468 !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
1469 InstTemplate->setInstantiatedFromMemberTemplate(D);
1471 // Make declarations visible in the appropriate context.
1473 Owner->addDecl(InstTemplate);
1474 } else if (InstTemplate->getDeclContext()->isRecord() &&
1475 !getPreviousDeclForInstantiation(D)) {
1476 SemaRef.CheckFriendAccess(InstTemplate);
1479 return InstTemplate;
1482 Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
1483 CXXRecordDecl *PrevDecl = nullptr;
1484 if (D->isInjectedClassName())
1485 PrevDecl = cast<CXXRecordDecl>(Owner);
1486 else if (CXXRecordDecl *PatternPrev = getPreviousDeclForInstantiation(D)) {
1487 NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
1490 if (!Prev) return nullptr;
1491 PrevDecl = cast<CXXRecordDecl>(Prev);
1494 CXXRecordDecl *Record
1495 = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
1496 D->getLocStart(), D->getLocation(),
1497 D->getIdentifier(), PrevDecl);
1499 // Substitute the nested name specifier, if any.
1500 if (SubstQualifier(D, Record))
1503 Record->setImplicit(D->isImplicit());
1504 // FIXME: Check against AS_none is an ugly hack to work around the issue that
1505 // the tag decls introduced by friend class declarations don't have an access
1506 // specifier. Remove once this area of the code gets sorted out.
1507 if (D->getAccess() != AS_none)
1508 Record->setAccess(D->getAccess());
1509 if (!D->isInjectedClassName())
1510 Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
1512 // If the original function was part of a friend declaration,
1513 // inherit its namespace state.
1514 if (D->getFriendObjectKind())
1515 Record->setObjectOfFriendDecl();
1517 // Make sure that anonymous structs and unions are recorded.
1518 if (D->isAnonymousStructOrUnion())
1519 Record->setAnonymousStructOrUnion(true);
1521 if (D->isLocalClass())
1522 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
1524 // Forward the mangling number from the template to the instantiated decl.
1525 SemaRef.Context.setManglingNumber(Record,
1526 SemaRef.Context.getManglingNumber(D));
1528 // See if the old tag was defined along with a declarator.
1529 // If it did, mark the new tag as being associated with that declarator.
1530 if (DeclaratorDecl *DD = SemaRef.Context.getDeclaratorForUnnamedTagDecl(D))
1531 SemaRef.Context.addDeclaratorForUnnamedTagDecl(Record, DD);
1533 // See if the old tag was defined along with a typedef.
1534 // If it did, mark the new tag as being associated with that typedef.
1535 if (TypedefNameDecl *TND = SemaRef.Context.getTypedefNameForUnnamedTagDecl(D))
1536 SemaRef.Context.addTypedefNameForUnnamedTagDecl(Record, TND);
1538 Owner->addDecl(Record);
1540 // DR1484 clarifies that the members of a local class are instantiated as part
1541 // of the instantiation of their enclosing entity.
1542 if (D->isCompleteDefinition() && D->isLocalClass()) {
1543 Sema::SavePendingLocalImplicitInstantiationsRAII
1544 SavedPendingLocalImplicitInstantiations(SemaRef);
1546 SemaRef.InstantiateClass(D->getLocation(), Record, D, TemplateArgs,
1547 TSK_ImplicitInstantiation,
1550 // For nested local classes, we will instantiate the members when we
1551 // reach the end of the outermost (non-nested) local class.
1552 if (!D->isCXXClassMember())
1553 SemaRef.InstantiateClassMembers(D->getLocation(), Record, TemplateArgs,
1554 TSK_ImplicitInstantiation);
1556 // This class may have local implicit instantiations that need to be
1557 // performed within this scope.
1558 SemaRef.PerformPendingInstantiations(/*LocalOnly=*/true);
1561 SemaRef.DiagnoseUnusedNestedTypedefs(Record);
1566 /// \brief Adjust the given function type for an instantiation of the
1567 /// given declaration, to cope with modifications to the function's type that
1568 /// aren't reflected in the type-source information.
1570 /// \param D The declaration we're instantiating.
1571 /// \param TInfo The already-instantiated type.
1572 static QualType adjustFunctionTypeForInstantiation(ASTContext &Context,
1574 TypeSourceInfo *TInfo) {
1575 const FunctionProtoType *OrigFunc
1576 = D->getType()->castAs<FunctionProtoType>();
1577 const FunctionProtoType *NewFunc
1578 = TInfo->getType()->castAs<FunctionProtoType>();
1579 if (OrigFunc->getExtInfo() == NewFunc->getExtInfo())
1580 return TInfo->getType();
1582 FunctionProtoType::ExtProtoInfo NewEPI = NewFunc->getExtProtoInfo();
1583 NewEPI.ExtInfo = OrigFunc->getExtInfo();
1584 return Context.getFunctionType(NewFunc->getReturnType(),
1585 NewFunc->getParamTypes(), NewEPI);
1588 /// Normal class members are of more specific types and therefore
1589 /// don't make it here. This function serves two purposes:
1590 /// 1) instantiating function templates
1591 /// 2) substituting friend declarations
1592 Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
1593 TemplateParameterList *TemplateParams) {
1594 // Check whether there is already a function template specialization for
1595 // this declaration.
1596 FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1597 if (FunctionTemplate && !TemplateParams) {
1598 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1600 void *InsertPos = nullptr;
1601 FunctionDecl *SpecFunc
1602 = FunctionTemplate->findSpecialization(Innermost, InsertPos);
1604 // If we already have a function template specialization, return it.
1610 if (FunctionTemplate)
1611 isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1613 isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1615 bool MergeWithParentScope = (TemplateParams != nullptr) ||
1616 Owner->isFunctionOrMethod() ||
1617 !(isa<Decl>(Owner) &&
1618 cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1619 LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1621 SmallVector<ParmVarDecl *, 4> Params;
1622 TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
1625 QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
1627 NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1629 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1635 // If we're instantiating a local function declaration, put the result
1636 // in the enclosing namespace; otherwise we need to find the instantiated
1639 if (D->isLocalExternDecl()) {
1641 SemaRef.adjustContextForLocalExternDecl(DC);
1642 } else if (isFriend && QualifierLoc) {
1644 SS.Adopt(QualifierLoc);
1645 DC = SemaRef.computeDeclContext(SS);
1646 if (!DC) return nullptr;
1648 DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1652 FunctionDecl *Function;
1653 if (auto *DGuide = dyn_cast<CXXDeductionGuideDecl>(D))
1654 Function = CXXDeductionGuideDecl::Create(
1655 SemaRef.Context, DC, D->getInnerLocStart(), DGuide->isExplicit(),
1656 D->getNameInfo(), T, TInfo, D->getSourceRange().getEnd());
1658 Function = FunctionDecl::Create(
1659 SemaRef.Context, DC, D->getInnerLocStart(), D->getNameInfo(), T, TInfo,
1660 D->getCanonicalDecl()->getStorageClass(), D->isInlineSpecified(),
1661 D->hasWrittenPrototype(), D->isConstexpr());
1662 Function->setRangeEnd(D->getSourceRange().getEnd());
1666 Function->setImplicitlyInline();
1669 Function->setQualifierInfo(QualifierLoc);
1671 if (D->isLocalExternDecl())
1672 Function->setLocalExternDecl();
1674 DeclContext *LexicalDC = Owner;
1675 if (!isFriend && D->isOutOfLine() && !D->isLocalExternDecl()) {
1676 assert(D->getDeclContext()->isFileContext());
1677 LexicalDC = D->getDeclContext();
1680 Function->setLexicalDeclContext(LexicalDC);
1682 // Attach the parameters
1683 for (unsigned P = 0; P < Params.size(); ++P)
1685 Params[P]->setOwningFunction(Function);
1686 Function->setParams(Params);
1688 SourceLocation InstantiateAtPOI;
1689 if (TemplateParams) {
1690 // Our resulting instantiation is actually a function template, since we
1691 // are substituting only the outer template parameters. For example, given
1693 // template<typename T>
1695 // template<typename U> friend void f(T, U);
1700 // We are instantiating the friend function template "f" within X<int>,
1701 // which means substituting int for T, but leaving "f" as a friend function
1703 // Build the function template itself.
1704 FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1705 Function->getLocation(),
1706 Function->getDeclName(),
1707 TemplateParams, Function);
1708 Function->setDescribedFunctionTemplate(FunctionTemplate);
1710 FunctionTemplate->setLexicalDeclContext(LexicalDC);
1712 if (isFriend && D->isThisDeclarationADefinition()) {
1713 FunctionTemplate->setInstantiatedFromMemberTemplate(
1714 D->getDescribedFunctionTemplate());
1716 } else if (FunctionTemplate) {
1717 // Record this function template specialization.
1718 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1719 Function->setFunctionTemplateSpecialization(FunctionTemplate,
1720 TemplateArgumentList::CreateCopy(SemaRef.Context,
1722 /*InsertPos=*/nullptr);
1723 } else if (isFriend && D->isThisDeclarationADefinition()) {
1724 // Do not connect the friend to the template unless it's actually a
1725 // definition. We don't want non-template functions to be marked as being
1726 // template instantiations.
1727 Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1730 if (InitFunctionInstantiation(Function, D))
1731 Function->setInvalidDecl();
1733 bool isExplicitSpecialization = false;
1735 LookupResult Previous(
1736 SemaRef, Function->getDeclName(), SourceLocation(),
1737 D->isLocalExternDecl() ? Sema::LookupRedeclarationWithLinkage
1738 : Sema::LookupOrdinaryName,
1739 Sema::ForRedeclaration);
1741 if (DependentFunctionTemplateSpecializationInfo *Info
1742 = D->getDependentSpecializationInfo()) {
1743 assert(isFriend && "non-friend has dependent specialization info?");
1745 // This needs to be set now for future sanity.
1746 Function->setObjectOfFriendDecl();
1748 // Instantiate the explicit template arguments.
1749 TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1750 Info->getRAngleLoc());
1751 if (SemaRef.Subst(Info->getTemplateArgs(), Info->getNumTemplateArgs(),
1752 ExplicitArgs, TemplateArgs))
1755 // Map the candidate templates to their instantiations.
1756 for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1757 Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1758 Info->getTemplate(I),
1760 if (!Temp) return nullptr;
1762 Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1765 if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1768 Function->setInvalidDecl();
1770 isExplicitSpecialization = true;
1772 } else if (TemplateParams || !FunctionTemplate) {
1773 // Look only into the namespace where the friend would be declared to
1774 // find a previous declaration. This is the innermost enclosing namespace,
1775 // as described in ActOnFriendFunctionDecl.
1776 SemaRef.LookupQualifiedName(Previous, DC);
1778 // In C++, the previous declaration we find might be a tag type
1779 // (class or enum). In this case, the new declaration will hide the
1780 // tag type. Note that this does does not apply if we're declaring a
1781 // typedef (C++ [dcl.typedef]p4).
1782 if (Previous.isSingleTagDecl())
1786 SemaRef.CheckFunctionDeclaration(/*Scope*/ nullptr, Function, Previous,
1787 isExplicitSpecialization);
1789 NamedDecl *PrincipalDecl = (TemplateParams
1790 ? cast<NamedDecl>(FunctionTemplate)
1793 // If the original function was part of a friend declaration,
1794 // inherit its namespace state and add it to the owner.
1796 PrincipalDecl->setObjectOfFriendDecl();
1797 DC->makeDeclVisibleInContext(PrincipalDecl);
1799 bool QueuedInstantiation = false;
1801 // C++11 [temp.friend]p4 (DR329):
1802 // When a function is defined in a friend function declaration in a class
1803 // template, the function is instantiated when the function is odr-used.
1804 // The same restrictions on multiple declarations and definitions that
1805 // apply to non-template function declarations and definitions also apply
1806 // to these implicit definitions.
1807 if (D->isThisDeclarationADefinition()) {
1808 // Check for a function body.
1809 const FunctionDecl *Definition = nullptr;
1810 if (Function->isDefined(Definition) &&
1811 Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1812 SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1813 << Function->getDeclName();
1814 SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1816 // Check for redefinitions due to other instantiations of this or
1817 // a similar friend function.
1818 else for (auto R : Function->redecls()) {
1822 // If some prior declaration of this function has been used, we need
1823 // to instantiate its definition.
1824 if (!QueuedInstantiation && R->isUsed(false)) {
1825 if (MemberSpecializationInfo *MSInfo =
1826 Function->getMemberSpecializationInfo()) {
1827 if (MSInfo->getPointOfInstantiation().isInvalid()) {
1828 SourceLocation Loc = R->getLocation(); // FIXME
1829 MSInfo->setPointOfInstantiation(Loc);
1830 SemaRef.PendingLocalImplicitInstantiations.push_back(
1831 std::make_pair(Function, Loc));
1832 QueuedInstantiation = true;
1837 // If some prior declaration of this function was a friend with an
1838 // uninstantiated definition, reject it.
1839 if (R->getFriendObjectKind()) {
1840 if (const FunctionDecl *RPattern =
1841 R->getTemplateInstantiationPattern()) {
1842 if (RPattern->isDefined(RPattern)) {
1843 SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1844 << Function->getDeclName();
1845 SemaRef.Diag(R->getLocation(), diag::note_previous_definition);
1854 if (Function->isLocalExternDecl() && !Function->getPreviousDecl())
1855 DC->makeDeclVisibleInContext(PrincipalDecl);
1857 if (Function->isOverloadedOperator() && !DC->isRecord() &&
1858 PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1859 PrincipalDecl->setNonMemberOperator();
1861 assert(!D->isDefaulted() && "only methods should be defaulted");
1866 TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1867 TemplateParameterList *TemplateParams,
1868 bool IsClassScopeSpecialization) {
1869 FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1870 if (FunctionTemplate && !TemplateParams) {
1871 // We are creating a function template specialization from a function
1872 // template. Check whether there is already a function template
1873 // specialization for this particular set of template arguments.
1874 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1876 void *InsertPos = nullptr;
1877 FunctionDecl *SpecFunc
1878 = FunctionTemplate->findSpecialization(Innermost, InsertPos);
1880 // If we already have a function template specialization, return it.
1886 if (FunctionTemplate)
1887 isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1889 isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1891 bool MergeWithParentScope = (TemplateParams != nullptr) ||
1892 !(isa<Decl>(Owner) &&
1893 cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1894 LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1896 // Instantiate enclosing template arguments for friends.
1897 SmallVector<TemplateParameterList *, 4> TempParamLists;
1898 unsigned NumTempParamLists = 0;
1899 if (isFriend && (NumTempParamLists = D->getNumTemplateParameterLists())) {
1900 TempParamLists.resize(NumTempParamLists);
1901 for (unsigned I = 0; I != NumTempParamLists; ++I) {
1902 TemplateParameterList *TempParams = D->getTemplateParameterList(I);
1903 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1906 TempParamLists[I] = InstParams;
1910 SmallVector<ParmVarDecl *, 4> Params;
1911 TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
1914 QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
1916 NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1918 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1924 DeclContext *DC = Owner;
1928 SS.Adopt(QualifierLoc);
1929 DC = SemaRef.computeDeclContext(SS);
1931 if (DC && SemaRef.RequireCompleteDeclContext(SS, DC))
1934 DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1935 D->getDeclContext(),
1938 if (!DC) return nullptr;
1941 // Build the instantiated method declaration.
1942 CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1943 CXXMethodDecl *Method = nullptr;
1945 SourceLocation StartLoc = D->getInnerLocStart();
1946 DeclarationNameInfo NameInfo
1947 = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1948 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1949 Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1950 StartLoc, NameInfo, T, TInfo,
1951 Constructor->isExplicit(),
1952 Constructor->isInlineSpecified(),
1953 false, Constructor->isConstexpr());
1954 Method->setRangeEnd(Constructor->getLocEnd());
1955 } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1956 Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1957 StartLoc, NameInfo, T, TInfo,
1958 Destructor->isInlineSpecified(),
1960 Method->setRangeEnd(Destructor->getLocEnd());
1961 } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1962 Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1963 StartLoc, NameInfo, T, TInfo,
1964 Conversion->isInlineSpecified(),
1965 Conversion->isExplicit(),
1966 Conversion->isConstexpr(),
1967 Conversion->getLocEnd());
1969 StorageClass SC = D->isStatic() ? SC_Static : SC_None;
1970 Method = CXXMethodDecl::Create(SemaRef.Context, Record,
1971 StartLoc, NameInfo, T, TInfo,
1972 SC, D->isInlineSpecified(),
1973 D->isConstexpr(), D->getLocEnd());
1977 Method->setImplicitlyInline();
1980 Method->setQualifierInfo(QualifierLoc);
1982 if (TemplateParams) {
1983 // Our resulting instantiation is actually a function template, since we
1984 // are substituting only the outer template parameters. For example, given
1986 // template<typename T>
1988 // template<typename U> void f(T, U);
1993 // We are instantiating the member template "f" within X<int>, which means
1994 // substituting int for T, but leaving "f" as a member function template.
1995 // Build the function template itself.
1996 FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1997 Method->getLocation(),
1998 Method->getDeclName(),
1999 TemplateParams, Method);
2001 FunctionTemplate->setLexicalDeclContext(Owner);
2002 FunctionTemplate->setObjectOfFriendDecl();
2003 } else if (D->isOutOfLine())
2004 FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
2005 Method->setDescribedFunctionTemplate(FunctionTemplate);
2006 } else if (FunctionTemplate) {
2007 // Record this function template specialization.
2008 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
2009 Method->setFunctionTemplateSpecialization(FunctionTemplate,
2010 TemplateArgumentList::CreateCopy(SemaRef.Context,
2012 /*InsertPos=*/nullptr);
2013 } else if (!isFriend) {
2014 // Record that this is an instantiation of a member function.
2015 Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
2018 // If we are instantiating a member function defined
2019 // out-of-line, the instantiation will have the same lexical
2020 // context (which will be a namespace scope) as the template.
2022 if (NumTempParamLists)
2023 Method->setTemplateParameterListsInfo(
2025 llvm::makeArrayRef(TempParamLists.data(), NumTempParamLists));
2027 Method->setLexicalDeclContext(Owner);
2028 Method->setObjectOfFriendDecl();
2029 } else if (D->isOutOfLine())
2030 Method->setLexicalDeclContext(D->getLexicalDeclContext());
2032 // Attach the parameters
2033 for (unsigned P = 0; P < Params.size(); ++P)
2034 Params[P]->setOwningFunction(Method);
2035 Method->setParams(Params);
2037 if (InitMethodInstantiation(Method, D))
2038 Method->setInvalidDecl();
2040 LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
2041 Sema::ForRedeclaration);
2043 if (!FunctionTemplate || TemplateParams || isFriend) {
2044 SemaRef.LookupQualifiedName(Previous, Record);
2046 // In C++, the previous declaration we find might be a tag type
2047 // (class or enum). In this case, the new declaration will hide the
2048 // tag type. Note that this does does not apply if we're declaring a
2049 // typedef (C++ [dcl.typedef]p4).
2050 if (Previous.isSingleTagDecl())
2054 if (!IsClassScopeSpecialization)
2055 SemaRef.CheckFunctionDeclaration(nullptr, Method, Previous, false);
2058 SemaRef.CheckPureMethod(Method, SourceRange());
2060 // Propagate access. For a non-friend declaration, the access is
2061 // whatever we're propagating from. For a friend, it should be the
2062 // previous declaration we just found.
2063 if (isFriend && Method->getPreviousDecl())
2064 Method->setAccess(Method->getPreviousDecl()->getAccess());
2066 Method->setAccess(D->getAccess());
2067 if (FunctionTemplate)
2068 FunctionTemplate->setAccess(Method->getAccess());
2070 SemaRef.CheckOverrideControl(Method);
2072 // If a function is defined as defaulted or deleted, mark it as such now.
2073 if (D->isExplicitlyDefaulted())
2074 SemaRef.SetDeclDefaulted(Method, Method->getLocation());
2075 if (D->isDeletedAsWritten())
2076 SemaRef.SetDeclDeleted(Method, Method->getLocation());
2078 // If there's a function template, let our caller handle it.
2079 if (FunctionTemplate) {
2082 // Don't hide a (potentially) valid declaration with an invalid one.
2083 } else if (Method->isInvalidDecl() && !Previous.empty()) {
2086 // Otherwise, check access to friends and make them visible.
2087 } else if (isFriend) {
2088 // We only need to re-check access for methods which we didn't
2089 // manage to match during parsing.
2090 if (!D->getPreviousDecl())
2091 SemaRef.CheckFriendAccess(Method);
2093 Record->makeDeclVisibleInContext(Method);
2095 // Otherwise, add the declaration. We don't need to do this for
2096 // class-scope specializations because we'll have matched them with
2097 // the appropriate template.
2098 } else if (!IsClassScopeSpecialization) {
2099 Owner->addDecl(Method);
2105 Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
2106 return VisitCXXMethodDecl(D);
2109 Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
2110 return VisitCXXMethodDecl(D);
2113 Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
2114 return VisitCXXMethodDecl(D);
2117 Decl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
2118 return SemaRef.SubstParmVarDecl(D, TemplateArgs, /*indexAdjustment*/ 0, None,
2119 /*ExpectParameterPack=*/ false);
2122 Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
2123 TemplateTypeParmDecl *D) {
2124 // TODO: don't always clone when decls are refcounted.
2125 assert(D->getTypeForDecl()->isTemplateTypeParmType());
2127 TemplateTypeParmDecl *Inst = TemplateTypeParmDecl::Create(
2128 SemaRef.Context, Owner, D->getLocStart(), D->getLocation(),
2129 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(), D->getIndex(),
2130 D->getIdentifier(), D->wasDeclaredWithTypename(), D->isParameterPack());
2131 Inst->setAccess(AS_public);
2133 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2134 TypeSourceInfo *InstantiatedDefaultArg =
2135 SemaRef.SubstType(D->getDefaultArgumentInfo(), TemplateArgs,
2136 D->getDefaultArgumentLoc(), D->getDeclName());
2137 if (InstantiatedDefaultArg)
2138 Inst->setDefaultArgument(InstantiatedDefaultArg);
2141 // Introduce this template parameter's instantiation into the instantiation
2143 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
2148 Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
2149 NonTypeTemplateParmDecl *D) {
2150 // Substitute into the type of the non-type template parameter.
2151 TypeLoc TL = D->getTypeSourceInfo()->getTypeLoc();
2152 SmallVector<TypeSourceInfo *, 4> ExpandedParameterPackTypesAsWritten;
2153 SmallVector<QualType, 4> ExpandedParameterPackTypes;
2154 bool IsExpandedParameterPack = false;
2157 bool Invalid = false;
2159 if (D->isExpandedParameterPack()) {
2160 // The non-type template parameter pack is an already-expanded pack
2161 // expansion of types. Substitute into each of the expanded types.
2162 ExpandedParameterPackTypes.reserve(D->getNumExpansionTypes());
2163 ExpandedParameterPackTypesAsWritten.reserve(D->getNumExpansionTypes());
2164 for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
2165 TypeSourceInfo *NewDI =
2166 SemaRef.SubstType(D->getExpansionTypeSourceInfo(I), TemplateArgs,
2167 D->getLocation(), D->getDeclName());
2172 SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
2176 ExpandedParameterPackTypesAsWritten.push_back(NewDI);
2177 ExpandedParameterPackTypes.push_back(NewT);
2180 IsExpandedParameterPack = true;
2181 DI = D->getTypeSourceInfo();
2183 } else if (D->isPackExpansion()) {
2184 // The non-type template parameter pack's type is a pack expansion of types.
2185 // Determine whether we need to expand this parameter pack into separate
2187 PackExpansionTypeLoc Expansion = TL.castAs<PackExpansionTypeLoc>();
2188 TypeLoc Pattern = Expansion.getPatternLoc();
2189 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2190 SemaRef.collectUnexpandedParameterPacks(Pattern, Unexpanded);
2192 // Determine whether the set of unexpanded parameter packs can and should
2195 bool RetainExpansion = false;
2196 Optional<unsigned> OrigNumExpansions
2197 = Expansion.getTypePtr()->getNumExpansions();
2198 Optional<unsigned> NumExpansions = OrigNumExpansions;
2199 if (SemaRef.CheckParameterPacksForExpansion(Expansion.getEllipsisLoc(),
2200 Pattern.getSourceRange(),
2203 Expand, RetainExpansion,
2208 for (unsigned I = 0; I != *NumExpansions; ++I) {
2209 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2210 TypeSourceInfo *NewDI = SemaRef.SubstType(Pattern, TemplateArgs,
2217 SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
2221 ExpandedParameterPackTypesAsWritten.push_back(NewDI);
2222 ExpandedParameterPackTypes.push_back(NewT);
2225 // Note that we have an expanded parameter pack. The "type" of this
2226 // expanded parameter pack is the original expansion type, but callers
2227 // will end up using the expanded parameter pack types for type-checking.
2228 IsExpandedParameterPack = true;
2229 DI = D->getTypeSourceInfo();
2232 // We cannot fully expand the pack expansion now, so substitute into the
2233 // pattern and create a new pack expansion type.
2234 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2235 TypeSourceInfo *NewPattern = SemaRef.SubstType(Pattern, TemplateArgs,
2241 SemaRef.CheckNonTypeTemplateParameterType(NewPattern, D->getLocation());
2242 DI = SemaRef.CheckPackExpansion(NewPattern, Expansion.getEllipsisLoc(),
2250 // Simple case: substitution into a parameter that is not a parameter pack.
2251 DI = SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
2252 D->getLocation(), D->getDeclName());
2256 // Check that this type is acceptable for a non-type template parameter.
2257 T = SemaRef.CheckNonTypeTemplateParameterType(DI, D->getLocation());
2259 T = SemaRef.Context.IntTy;
2264 NonTypeTemplateParmDecl *Param;
2265 if (IsExpandedParameterPack)
2266 Param = NonTypeTemplateParmDecl::Create(
2267 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
2268 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2269 D->getPosition(), D->getIdentifier(), T, DI, ExpandedParameterPackTypes,
2270 ExpandedParameterPackTypesAsWritten);
2272 Param = NonTypeTemplateParmDecl::Create(
2273 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
2274 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2275 D->getPosition(), D->getIdentifier(), T, D->isParameterPack(), DI);
2277 Param->setAccess(AS_public);
2279 Param->setInvalidDecl();
2281 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2282 EnterExpressionEvaluationContext ConstantEvaluated(
2283 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
2284 ExprResult Value = SemaRef.SubstExpr(D->getDefaultArgument(), TemplateArgs);
2285 if (!Value.isInvalid())
2286 Param->setDefaultArgument(Value.get());
2289 // Introduce this template parameter's instantiation into the instantiation
2291 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
2295 static void collectUnexpandedParameterPacks(
2297 TemplateParameterList *Params,
2298 SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) {
2299 for (const auto &P : *Params) {
2300 if (P->isTemplateParameterPack())
2302 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P))
2303 S.collectUnexpandedParameterPacks(NTTP->getTypeSourceInfo()->getTypeLoc(),
2305 if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(P))
2306 collectUnexpandedParameterPacks(S, TTP->getTemplateParameters(),
2312 TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
2313 TemplateTemplateParmDecl *D) {
2314 // Instantiate the template parameter list of the template template parameter.
2315 TemplateParameterList *TempParams = D->getTemplateParameters();
2316 TemplateParameterList *InstParams;
2317 SmallVector<TemplateParameterList*, 8> ExpandedParams;
2319 bool IsExpandedParameterPack = false;
2321 if (D->isExpandedParameterPack()) {
2322 // The template template parameter pack is an already-expanded pack
2323 // expansion of template parameters. Substitute into each of the expanded
2325 ExpandedParams.reserve(D->getNumExpansionTemplateParameters());
2326 for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
2328 LocalInstantiationScope Scope(SemaRef);
2329 TemplateParameterList *Expansion =
2330 SubstTemplateParams(D->getExpansionTemplateParameters(I));
2333 ExpandedParams.push_back(Expansion);
2336 IsExpandedParameterPack = true;
2337 InstParams = TempParams;
2338 } else if (D->isPackExpansion()) {
2339 // The template template parameter pack expands to a pack of template
2340 // template parameters. Determine whether we need to expand this parameter
2341 // pack into separate parameters.
2342 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2343 collectUnexpandedParameterPacks(SemaRef, D->getTemplateParameters(),
2346 // Determine whether the set of unexpanded parameter packs can and should
2349 bool RetainExpansion = false;
2350 Optional<unsigned> NumExpansions;
2351 if (SemaRef.CheckParameterPacksForExpansion(D->getLocation(),
2352 TempParams->getSourceRange(),
2355 Expand, RetainExpansion,
2360 for (unsigned I = 0; I != *NumExpansions; ++I) {
2361 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2362 LocalInstantiationScope Scope(SemaRef);
2363 TemplateParameterList *Expansion = SubstTemplateParams(TempParams);
2366 ExpandedParams.push_back(Expansion);
2369 // Note that we have an expanded parameter pack. The "type" of this
2370 // expanded parameter pack is the original expansion type, but callers
2371 // will end up using the expanded parameter pack types for type-checking.
2372 IsExpandedParameterPack = true;
2373 InstParams = TempParams;
2375 // We cannot fully expand the pack expansion now, so just substitute
2376 // into the pattern.
2377 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2379 LocalInstantiationScope Scope(SemaRef);
2380 InstParams = SubstTemplateParams(TempParams);
2385 // Perform the actual substitution of template parameters within a new,
2386 // local instantiation scope.
2387 LocalInstantiationScope Scope(SemaRef);
2388 InstParams = SubstTemplateParams(TempParams);
2393 // Build the template template parameter.
2394 TemplateTemplateParmDecl *Param;
2395 if (IsExpandedParameterPack)
2396 Param = TemplateTemplateParmDecl::Create(
2397 SemaRef.Context, Owner, D->getLocation(),
2398 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2399 D->getPosition(), D->getIdentifier(), InstParams, ExpandedParams);
2401 Param = TemplateTemplateParmDecl::Create(
2402 SemaRef.Context, Owner, D->getLocation(),
2403 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2404 D->getPosition(), D->isParameterPack(), D->getIdentifier(), InstParams);
2405 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2406 NestedNameSpecifierLoc QualifierLoc =
2407 D->getDefaultArgument().getTemplateQualifierLoc();
2409 SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgs);
2410 TemplateName TName = SemaRef.SubstTemplateName(
2411 QualifierLoc, D->getDefaultArgument().getArgument().getAsTemplate(),
2412 D->getDefaultArgument().getTemplateNameLoc(), TemplateArgs);
2413 if (!TName.isNull())
2414 Param->setDefaultArgument(
2416 TemplateArgumentLoc(TemplateArgument(TName),
2417 D->getDefaultArgument().getTemplateQualifierLoc(),
2418 D->getDefaultArgument().getTemplateNameLoc()));
2420 Param->setAccess(AS_public);
2422 // Introduce this template parameter's instantiation into the instantiation
2424 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
2429 Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
2430 // Using directives are never dependent (and never contain any types or
2431 // expressions), so they require no explicit instantiation work.
2433 UsingDirectiveDecl *Inst
2434 = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
2435 D->getNamespaceKeyLocation(),
2436 D->getQualifierLoc(),
2437 D->getIdentLocation(),
2438 D->getNominatedNamespace(),
2439 D->getCommonAncestor());
2441 // Add the using directive to its declaration context
2442 // only if this is not a function or method.
2443 if (!Owner->isFunctionOrMethod())
2444 Owner->addDecl(Inst);
2449 Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
2451 // The nested name specifier may be dependent, for example
2452 // template <typename T> struct t {
2453 // struct s1 { T f1(); };
2454 // struct s2 : s1 { using s1::f1; };
2456 // template struct t<int>;
2457 // Here, in using s1::f1, s1 refers to t<T>::s1;
2458 // we need to substitute for t<int>::s1.
2459 NestedNameSpecifierLoc QualifierLoc
2460 = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
2465 // For an inheriting constructor declaration, the name of the using
2466 // declaration is the name of a constructor in this class, not in the
2468 DeclarationNameInfo NameInfo = D->getNameInfo();
2469 if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName)
2470 if (auto *RD = dyn_cast<CXXRecordDecl>(SemaRef.CurContext))
2471 NameInfo.setName(SemaRef.Context.DeclarationNames.getCXXConstructorName(
2472 SemaRef.Context.getCanonicalType(SemaRef.Context.getRecordType(RD))));
2474 // We only need to do redeclaration lookups if we're in a class
2475 // scope (in fact, it's not really even possible in non-class
2477 bool CheckRedeclaration = Owner->isRecord();
2479 LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
2480 Sema::ForRedeclaration);
2482 UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
2489 SS.Adopt(QualifierLoc);
2490 if (CheckRedeclaration) {
2491 Prev.setHideTags(false);
2492 SemaRef.LookupQualifiedName(Prev, Owner);
2494 // Check for invalid redeclarations.
2495 if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLoc(),
2496 D->hasTypename(), SS,
2497 D->getLocation(), Prev))
2498 NewUD->setInvalidDecl();
2502 if (!NewUD->isInvalidDecl() &&
2503 SemaRef.CheckUsingDeclQualifier(D->getUsingLoc(), D->hasTypename(),
2504 SS, NameInfo, D->getLocation()))
2505 NewUD->setInvalidDecl();
2507 SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
2508 NewUD->setAccess(D->getAccess());
2509 Owner->addDecl(NewUD);
2511 // Don't process the shadow decls for an invalid decl.
2512 if (NewUD->isInvalidDecl())
2515 if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName)
2516 SemaRef.CheckInheritingConstructorUsingDecl(NewUD);
2518 bool isFunctionScope = Owner->isFunctionOrMethod();
2520 // Process the shadow decls.
2521 for (auto *Shadow : D->shadows()) {
2522 // FIXME: UsingShadowDecl doesn't preserve its immediate target, so
2523 // reconstruct it in the case where it matters.
2524 NamedDecl *OldTarget = Shadow->getTargetDecl();
2525 if (auto *CUSD = dyn_cast<ConstructorUsingShadowDecl>(Shadow))
2526 if (auto *BaseShadow = CUSD->getNominatedBaseClassShadowDecl())
2527 OldTarget = BaseShadow;
2529 NamedDecl *InstTarget =
2530 cast_or_null<NamedDecl>(SemaRef.FindInstantiatedDecl(
2531 Shadow->getLocation(), OldTarget, TemplateArgs));
2535 UsingShadowDecl *PrevDecl = nullptr;
2536 if (CheckRedeclaration) {
2537 if (SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev, PrevDecl))
2539 } else if (UsingShadowDecl *OldPrev =
2540 getPreviousDeclForInstantiation(Shadow)) {
2541 PrevDecl = cast_or_null<UsingShadowDecl>(SemaRef.FindInstantiatedDecl(
2542 Shadow->getLocation(), OldPrev, TemplateArgs));
2545 UsingShadowDecl *InstShadow =
2546 SemaRef.BuildUsingShadowDecl(/*Scope*/nullptr, NewUD, InstTarget,
2548 SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
2550 if (isFunctionScope)
2551 SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
2557 Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
2558 // Ignore these; we handle them in bulk when processing the UsingDecl.
2562 Decl *TemplateDeclInstantiator::VisitConstructorUsingShadowDecl(
2563 ConstructorUsingShadowDecl *D) {
2564 // Ignore these; we handle them in bulk when processing the UsingDecl.
2568 template <typename T>
2569 Decl *TemplateDeclInstantiator::instantiateUnresolvedUsingDecl(
2570 T *D, bool InstantiatingPackElement) {
2571 // If this is a pack expansion, expand it now.
2572 if (D->isPackExpansion() && !InstantiatingPackElement) {
2573 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2574 SemaRef.collectUnexpandedParameterPacks(D->getQualifierLoc(), Unexpanded);
2575 SemaRef.collectUnexpandedParameterPacks(D->getNameInfo(), Unexpanded);
2577 // Determine whether the set of unexpanded parameter packs can and should
2580 bool RetainExpansion = false;
2581 Optional<unsigned> NumExpansions;
2582 if (SemaRef.CheckParameterPacksForExpansion(
2583 D->getEllipsisLoc(), D->getSourceRange(), Unexpanded, TemplateArgs,
2584 Expand, RetainExpansion, NumExpansions))
2587 // This declaration cannot appear within a function template signature,
2588 // so we can't have a partial argument list for a parameter pack.
2589 assert(!RetainExpansion &&
2590 "should never need to retain an expansion for UsingPackDecl");
2593 // We cannot fully expand the pack expansion now, so substitute into the
2594 // pattern and create a new pack expansion.
2595 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2596 return instantiateUnresolvedUsingDecl(D, true);
2599 // Within a function, we don't have any normal way to check for conflicts
2600 // between shadow declarations from different using declarations in the
2601 // same pack expansion, but this is always ill-formed because all expansions
2602 // must produce (conflicting) enumerators.
2604 // Sadly we can't just reject this in the template definition because it
2605 // could be valid if the pack is empty or has exactly one expansion.
2606 if (D->getDeclContext()->isFunctionOrMethod() && *NumExpansions > 1) {
2607 SemaRef.Diag(D->getEllipsisLoc(),
2608 diag::err_using_decl_redeclaration_expansion);
2612 // Instantiate the slices of this pack and build a UsingPackDecl.
2613 SmallVector<NamedDecl*, 8> Expansions;
2614 for (unsigned I = 0; I != *NumExpansions; ++I) {
2615 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2616 Decl *Slice = instantiateUnresolvedUsingDecl(D, true);
2619 // Note that we can still get unresolved using declarations here, if we
2620 // had arguments for all packs but the pattern also contained other
2621 // template arguments (this only happens during partial substitution, eg
2622 // into the body of a generic lambda in a function template).
2623 Expansions.push_back(cast<NamedDecl>(Slice));
2626 auto *NewD = SemaRef.BuildUsingPackDecl(D, Expansions);
2627 if (isDeclWithinFunction(D))
2628 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewD);
2632 UnresolvedUsingTypenameDecl *TD = dyn_cast<UnresolvedUsingTypenameDecl>(D);
2633 SourceLocation TypenameLoc = TD ? TD->getTypenameLoc() : SourceLocation();
2635 NestedNameSpecifierLoc QualifierLoc
2636 = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
2642 SS.Adopt(QualifierLoc);
2644 DeclarationNameInfo NameInfo
2645 = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
2647 // Produce a pack expansion only if we're not instantiating a particular
2648 // slice of a pack expansion.
2649 bool InstantiatingSlice = D->getEllipsisLoc().isValid() &&
2650 SemaRef.ArgumentPackSubstitutionIndex != -1;
2651 SourceLocation EllipsisLoc =
2652 InstantiatingSlice ? SourceLocation() : D->getEllipsisLoc();
2654 NamedDecl *UD = SemaRef.BuildUsingDeclaration(
2655 /*Scope*/ nullptr, D->getAccess(), D->getUsingLoc(),
2656 /*HasTypename*/ TD, TypenameLoc, SS, NameInfo, EllipsisLoc, nullptr,
2657 /*IsInstantiation*/ true);
2659 SemaRef.Context.setInstantiatedFromUsingDecl(UD, D);
2664 Decl *TemplateDeclInstantiator::VisitUnresolvedUsingTypenameDecl(
2665 UnresolvedUsingTypenameDecl *D) {
2666 return instantiateUnresolvedUsingDecl(D);
2669 Decl *TemplateDeclInstantiator::VisitUnresolvedUsingValueDecl(
2670 UnresolvedUsingValueDecl *D) {
2671 return instantiateUnresolvedUsingDecl(D);
2674 Decl *TemplateDeclInstantiator::VisitUsingPackDecl(UsingPackDecl *D) {
2675 SmallVector<NamedDecl*, 8> Expansions;
2676 for (auto *UD : D->expansions()) {
2678 SemaRef.FindInstantiatedDecl(D->getLocation(), UD, TemplateArgs))
2679 Expansions.push_back(cast<NamedDecl>(NewUD));
2684 auto *NewD = SemaRef.BuildUsingPackDecl(D, Expansions);
2685 if (isDeclWithinFunction(D))
2686 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewD);
2690 Decl *TemplateDeclInstantiator::VisitClassScopeFunctionSpecializationDecl(
2691 ClassScopeFunctionSpecializationDecl *Decl) {
2692 CXXMethodDecl *OldFD = Decl->getSpecialization();
2693 CXXMethodDecl *NewFD =
2694 cast_or_null<CXXMethodDecl>(VisitCXXMethodDecl(OldFD, nullptr, true));
2698 LookupResult Previous(SemaRef, NewFD->getNameInfo(), Sema::LookupOrdinaryName,
2699 Sema::ForRedeclaration);
2701 TemplateArgumentListInfo TemplateArgs;
2702 TemplateArgumentListInfo *TemplateArgsPtr = nullptr;
2703 if (Decl->hasExplicitTemplateArgs()) {
2704 TemplateArgs = Decl->templateArgs();
2705 TemplateArgsPtr = &TemplateArgs;
2708 SemaRef.LookupQualifiedName(Previous, SemaRef.CurContext);
2709 if (SemaRef.CheckFunctionTemplateSpecialization(NewFD, TemplateArgsPtr,
2711 NewFD->setInvalidDecl();
2715 // Associate the specialization with the pattern.
2716 FunctionDecl *Specialization = cast<FunctionDecl>(Previous.getFoundDecl());
2717 assert(Specialization && "Class scope Specialization is null");
2718 SemaRef.Context.setClassScopeSpecializationPattern(Specialization, OldFD);
2723 Decl *TemplateDeclInstantiator::VisitOMPThreadPrivateDecl(
2724 OMPThreadPrivateDecl *D) {
2725 SmallVector<Expr *, 5> Vars;
2726 for (auto *I : D->varlists()) {
2727 Expr *Var = SemaRef.SubstExpr(I, TemplateArgs).get();
2728 assert(isa<DeclRefExpr>(Var) && "threadprivate arg is not a DeclRefExpr");
2729 Vars.push_back(Var);
2732 OMPThreadPrivateDecl *TD =
2733 SemaRef.CheckOMPThreadPrivateDecl(D->getLocation(), Vars);
2735 TD->setAccess(AS_public);
2741 Decl *TemplateDeclInstantiator::VisitOMPDeclareReductionDecl(
2742 OMPDeclareReductionDecl *D) {
2743 // Instantiate type and check if it is allowed.
2744 QualType SubstReductionType = SemaRef.ActOnOpenMPDeclareReductionType(
2746 ParsedType::make(SemaRef.SubstType(D->getType(), TemplateArgs,
2747 D->getLocation(), DeclarationName())));
2748 if (SubstReductionType.isNull())
2750 bool IsCorrect = !SubstReductionType.isNull();
2751 // Create instantiated copy.
2752 std::pair<QualType, SourceLocation> ReductionTypes[] = {
2753 std::make_pair(SubstReductionType, D->getLocation())};
2754 auto *PrevDeclInScope = D->getPrevDeclInScope();
2755 if (PrevDeclInScope && !PrevDeclInScope->isInvalidDecl()) {
2756 PrevDeclInScope = cast<OMPDeclareReductionDecl>(
2757 SemaRef.CurrentInstantiationScope->findInstantiationOf(PrevDeclInScope)
2760 auto DRD = SemaRef.ActOnOpenMPDeclareReductionDirectiveStart(
2761 /*S=*/nullptr, Owner, D->getDeclName(), ReductionTypes, D->getAccess(),
2763 auto *NewDRD = cast<OMPDeclareReductionDecl>(DRD.get().getSingleDecl());
2764 if (isDeclWithinFunction(NewDRD))
2765 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewDRD);
2766 Expr *SubstCombiner = nullptr;
2767 Expr *SubstInitializer = nullptr;
2768 // Combiners instantiation sequence.
2769 if (D->getCombiner()) {
2770 SemaRef.ActOnOpenMPDeclareReductionCombinerStart(
2771 /*S=*/nullptr, NewDRD);
2772 const char *Names[] = {"omp_in", "omp_out"};
2773 for (auto &Name : Names) {
2774 DeclarationName DN(&SemaRef.Context.Idents.get(Name));
2775 auto OldLookup = D->lookup(DN);
2776 auto Lookup = NewDRD->lookup(DN);
2777 if (!OldLookup.empty() && !Lookup.empty()) {
2778 assert(Lookup.size() == 1 && OldLookup.size() == 1);
2779 SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldLookup.front(),
2783 SubstCombiner = SemaRef.SubstExpr(D->getCombiner(), TemplateArgs).get();
2784 SemaRef.ActOnOpenMPDeclareReductionCombinerEnd(NewDRD, SubstCombiner);
2785 // Initializers instantiation sequence.
2786 if (D->getInitializer()) {
2787 SemaRef.ActOnOpenMPDeclareReductionInitializerStart(
2788 /*S=*/nullptr, NewDRD);
2789 const char *Names[] = {"omp_orig", "omp_priv"};
2790 for (auto &Name : Names) {
2791 DeclarationName DN(&SemaRef.Context.Idents.get(Name));
2792 auto OldLookup = D->lookup(DN);
2793 auto Lookup = NewDRD->lookup(DN);
2794 if (!OldLookup.empty() && !Lookup.empty()) {
2795 assert(Lookup.size() == 1 && OldLookup.size() == 1);
2796 SemaRef.CurrentInstantiationScope->InstantiatedLocal(
2797 OldLookup.front(), Lookup.front());
2801 SemaRef.SubstExpr(D->getInitializer(), TemplateArgs).get();
2802 SemaRef.ActOnOpenMPDeclareReductionInitializerEnd(NewDRD,
2805 IsCorrect = IsCorrect && SubstCombiner &&
2806 (!D->getInitializer() || SubstInitializer);
2810 (void)SemaRef.ActOnOpenMPDeclareReductionDirectiveEnd(/*S=*/nullptr, DRD,
2816 Decl *TemplateDeclInstantiator::VisitOMPCapturedExprDecl(
2817 OMPCapturedExprDecl * /*D*/) {
2818 llvm_unreachable("Should not be met in templates");
2821 Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D) {
2822 return VisitFunctionDecl(D, nullptr);
2826 TemplateDeclInstantiator::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
2827 return VisitFunctionDecl(D, nullptr);
2830 Decl *TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D) {
2831 return VisitCXXMethodDecl(D, nullptr);
2834 Decl *TemplateDeclInstantiator::VisitRecordDecl(RecordDecl *D) {
2835 llvm_unreachable("There are only CXXRecordDecls in C++");
2839 TemplateDeclInstantiator::VisitClassTemplateSpecializationDecl(
2840 ClassTemplateSpecializationDecl *D) {
2841 // As a MS extension, we permit class-scope explicit specialization
2842 // of member class templates.
2843 ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
2844 assert(ClassTemplate->getDeclContext()->isRecord() &&
2845 D->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
2846 "can only instantiate an explicit specialization "
2847 "for a member class template");
2849 // Lookup the already-instantiated declaration in the instantiation
2850 // of the class template. FIXME: Diagnose or assert if this fails?
2851 DeclContext::lookup_result Found
2852 = Owner->lookup(ClassTemplate->getDeclName());
2855 ClassTemplateDecl *InstClassTemplate
2856 = dyn_cast<ClassTemplateDecl>(Found.front());
2857 if (!InstClassTemplate)
2860 // Substitute into the template arguments of the class template explicit
2862 TemplateSpecializationTypeLoc Loc = D->getTypeAsWritten()->getTypeLoc().
2863 castAs<TemplateSpecializationTypeLoc>();
2864 TemplateArgumentListInfo InstTemplateArgs(Loc.getLAngleLoc(),
2865 Loc.getRAngleLoc());
2866 SmallVector<TemplateArgumentLoc, 4> ArgLocs;
2867 for (unsigned I = 0; I != Loc.getNumArgs(); ++I)
2868 ArgLocs.push_back(Loc.getArgLoc(I));
2869 if (SemaRef.Subst(ArgLocs.data(), ArgLocs.size(),
2870 InstTemplateArgs, TemplateArgs))
2873 // Check that the template argument list is well-formed for this
2875 SmallVector<TemplateArgument, 4> Converted;
2876 if (SemaRef.CheckTemplateArgumentList(InstClassTemplate,
2883 // Figure out where to insert this class template explicit specialization
2884 // in the member template's set of class template explicit specializations.
2885 void *InsertPos = nullptr;
2886 ClassTemplateSpecializationDecl *PrevDecl =
2887 InstClassTemplate->findSpecialization(Converted, InsertPos);
2889 // Check whether we've already seen a conflicting instantiation of this
2890 // declaration (for instance, if there was a prior implicit instantiation).
2893 SemaRef.CheckSpecializationInstantiationRedecl(D->getLocation(),
2894 D->getSpecializationKind(),
2896 PrevDecl->getSpecializationKind(),
2897 PrevDecl->getPointOfInstantiation(),
2901 // If PrevDecl was a definition and D is also a definition, diagnose.
2902 // This happens in cases like:
2904 // template<typename T, typename U>
2906 // template<typename X> struct Inner;
2907 // template<> struct Inner<T> {};
2908 // template<> struct Inner<U> {};
2911 // Outer<int, int> outer; // error: the explicit specializations of Inner
2912 // // have the same signature.
2913 if (PrevDecl && PrevDecl->getDefinition() &&
2914 D->isThisDeclarationADefinition()) {
2915 SemaRef.Diag(D->getLocation(), diag::err_redefinition) << PrevDecl;
2916 SemaRef.Diag(PrevDecl->getDefinition()->getLocation(),
2917 diag::note_previous_definition);
2921 // Create the class template partial specialization declaration.
2922 ClassTemplateSpecializationDecl *InstD
2923 = ClassTemplateSpecializationDecl::Create(SemaRef.Context,
2932 // Add this partial specialization to the set of class template partial
2935 InstClassTemplate->AddSpecialization(InstD, InsertPos);
2937 // Substitute the nested name specifier, if any.
2938 if (SubstQualifier(D, InstD))
2941 // Build the canonical type that describes the converted template
2942 // arguments of the class template explicit specialization.
2943 QualType CanonType = SemaRef.Context.getTemplateSpecializationType(
2944 TemplateName(InstClassTemplate), Converted,
2945 SemaRef.Context.getRecordType(InstD));
2947 // Build the fully-sugared type for this class template
2948 // specialization as the user wrote in the specialization
2949 // itself. This means that we'll pretty-print the type retrieved
2950 // from the specialization's declaration the way that the user
2951 // actually wrote the specialization, rather than formatting the
2952 // name based on the "canonical" representation used to store the
2953 // template arguments in the specialization.
2954 TypeSourceInfo *WrittenTy = SemaRef.Context.getTemplateSpecializationTypeInfo(
2955 TemplateName(InstClassTemplate), D->getLocation(), InstTemplateArgs,
2958 InstD->setAccess(D->getAccess());
2959 InstD->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
2960 InstD->setSpecializationKind(D->getSpecializationKind());
2961 InstD->setTypeAsWritten(WrittenTy);
2962 InstD->setExternLoc(D->getExternLoc());
2963 InstD->setTemplateKeywordLoc(D->getTemplateKeywordLoc());
2965 Owner->addDecl(InstD);
2967 // Instantiate the members of the class-scope explicit specialization eagerly.
2968 // We don't have support for lazy instantiation of an explicit specialization
2969 // yet, and MSVC eagerly instantiates in this case.
2970 if (D->isThisDeclarationADefinition() &&
2971 SemaRef.InstantiateClass(D->getLocation(), InstD, D, TemplateArgs,
2972 TSK_ImplicitInstantiation,
2979 Decl *TemplateDeclInstantiator::VisitVarTemplateSpecializationDecl(
2980 VarTemplateSpecializationDecl *D) {
2982 TemplateArgumentListInfo VarTemplateArgsInfo;
2983 VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
2984 assert(VarTemplate &&
2985 "A template specialization without specialized template?");
2987 // Substitute the current template arguments.
2988 const TemplateArgumentListInfo &TemplateArgsInfo = D->getTemplateArgsInfo();
2989 VarTemplateArgsInfo.setLAngleLoc(TemplateArgsInfo.getLAngleLoc());
2990 VarTemplateArgsInfo.setRAngleLoc(TemplateArgsInfo.getRAngleLoc());
2992 if (SemaRef.Subst(TemplateArgsInfo.getArgumentArray(),
2993 TemplateArgsInfo.size(), VarTemplateArgsInfo, TemplateArgs))
2996 // Check that the template argument list is well-formed for this template.
2997 SmallVector<TemplateArgument, 4> Converted;
2998 if (SemaRef.CheckTemplateArgumentList(
2999 VarTemplate, VarTemplate->getLocStart(),
3000 const_cast<TemplateArgumentListInfo &>(VarTemplateArgsInfo), false,
3004 // Find the variable template specialization declaration that
3005 // corresponds to these arguments.
3006 void *InsertPos = nullptr;
3007 if (VarTemplateSpecializationDecl *VarSpec = VarTemplate->findSpecialization(
3008 Converted, InsertPos))
3009 // If we already have a variable template specialization, return it.
3012 return VisitVarTemplateSpecializationDecl(VarTemplate, D, InsertPos,
3013 VarTemplateArgsInfo, Converted);
3016 Decl *TemplateDeclInstantiator::VisitVarTemplateSpecializationDecl(
3017 VarTemplateDecl *VarTemplate, VarDecl *D, void *InsertPos,
3018 const TemplateArgumentListInfo &TemplateArgsInfo,
3019 ArrayRef<TemplateArgument> Converted) {
3021 // Do substitution on the type of the declaration
3022 TypeSourceInfo *DI =
3023 SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
3024 D->getTypeSpecStartLoc(), D->getDeclName());
3028 if (DI->getType()->isFunctionType()) {
3029 SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
3030 << D->isStaticDataMember() << DI->getType();
3034 // Build the instantiated declaration
3035 VarTemplateSpecializationDecl *Var = VarTemplateSpecializationDecl::Create(
3036 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
3037 VarTemplate, DI->getType(), DI, D->getStorageClass(), Converted);
3038 Var->setTemplateArgsInfo(TemplateArgsInfo);
3040 VarTemplate->AddSpecialization(Var, InsertPos);
3042 // Substitute the nested name specifier, if any.
3043 if (SubstQualifier(D, Var))
3046 SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs,
3047 Owner, StartingScope);
3052 Decl *TemplateDeclInstantiator::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
3053 llvm_unreachable("@defs is not supported in Objective-C++");
3056 Decl *TemplateDeclInstantiator::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
3057 // FIXME: We need to be able to instantiate FriendTemplateDecls.
3058 unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
3059 DiagnosticsEngine::Error,
3060 "cannot instantiate %0 yet");
3061 SemaRef.Diag(D->getLocation(), DiagID)
3062 << D->getDeclKindName();
3067 Decl *TemplateDeclInstantiator::VisitDecl(Decl *D) {
3068 llvm_unreachable("Unexpected decl");
3071 Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
3072 const MultiLevelTemplateArgumentList &TemplateArgs) {
3073 TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
3074 if (D->isInvalidDecl())
3077 return Instantiator.Visit(D);
3080 /// \brief Instantiates a nested template parameter list in the current
3081 /// instantiation context.
3083 /// \param L The parameter list to instantiate
3085 /// \returns NULL if there was an error
3086 TemplateParameterList *
3087 TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
3088 // Get errors for all the parameters before bailing out.
3089 bool Invalid = false;
3091 unsigned N = L->size();
3092 typedef SmallVector<NamedDecl *, 8> ParamVector;
3095 for (auto &P : *L) {
3096 NamedDecl *D = cast_or_null<NamedDecl>(Visit(P));
3097 Params.push_back(D);
3098 Invalid = Invalid || !D || D->isInvalidDecl();
3101 // Clean up if we had an error.
3105 // Note: we substitute into associated constraints later
3106 Expr *const UninstantiatedRequiresClause = L->getRequiresClause();
3108 TemplateParameterList *InstL
3109 = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
3110 L->getLAngleLoc(), Params,
3112 UninstantiatedRequiresClause);
3116 /// \brief Instantiate the declaration of a class template partial
3119 /// \param ClassTemplate the (instantiated) class template that is partially
3120 // specialized by the instantiation of \p PartialSpec.
3122 /// \param PartialSpec the (uninstantiated) class template partial
3123 /// specialization that we are instantiating.
3125 /// \returns The instantiated partial specialization, if successful; otherwise,
3126 /// NULL to indicate an error.
3127 ClassTemplatePartialSpecializationDecl *
3128 TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
3129 ClassTemplateDecl *ClassTemplate,
3130 ClassTemplatePartialSpecializationDecl *PartialSpec) {
3131 // Create a local instantiation scope for this class template partial
3132 // specialization, which will contain the instantiations of the template
3134 LocalInstantiationScope Scope(SemaRef);
3136 // Substitute into the template parameters of the class template partial
3138 TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
3139 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
3143 // Substitute into the template arguments of the class template partial
3145 const ASTTemplateArgumentListInfo *TemplArgInfo
3146 = PartialSpec->getTemplateArgsAsWritten();
3147 TemplateArgumentListInfo InstTemplateArgs(TemplArgInfo->LAngleLoc,
3148 TemplArgInfo->RAngleLoc);
3149 if (SemaRef.Subst(TemplArgInfo->getTemplateArgs(),
3150 TemplArgInfo->NumTemplateArgs,
3151 InstTemplateArgs, TemplateArgs))
3154 // Check that the template argument list is well-formed for this
3156 SmallVector<TemplateArgument, 4> Converted;
3157 if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
3158 PartialSpec->getLocation(),
3164 // Check these arguments are valid for a template partial specialization.
3165 if (SemaRef.CheckTemplatePartialSpecializationArgs(
3166 PartialSpec->getLocation(), ClassTemplate, InstTemplateArgs.size(),
3170 // Figure out where to insert this class template partial specialization
3171 // in the member template's set of class template partial specializations.
3172 void *InsertPos = nullptr;
3173 ClassTemplateSpecializationDecl *PrevDecl
3174 = ClassTemplate->findPartialSpecialization(Converted, InsertPos);
3176 // Build the canonical type that describes the converted template
3177 // arguments of the class template partial specialization.
3179 = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
3182 // Build the fully-sugared type for this class template
3183 // specialization as the user wrote in the specialization
3184 // itself. This means that we'll pretty-print the type retrieved
3185 // from the specialization's declaration the way that the user
3186 // actually wrote the specialization, rather than formatting the
3187 // name based on the "canonical" representation used to store the
3188 // template arguments in the specialization.
3189 TypeSourceInfo *WrittenTy
3190 = SemaRef.Context.getTemplateSpecializationTypeInfo(
3191 TemplateName(ClassTemplate),
3192 PartialSpec->getLocation(),
3197 // We've already seen a partial specialization with the same template
3198 // parameters and template arguments. This can happen, for example, when
3199 // substituting the outer template arguments ends up causing two
3200 // class template partial specializations of a member class template
3201 // to have identical forms, e.g.,
3203 // template<typename T, typename U>
3205 // template<typename X, typename Y> struct Inner;
3206 // template<typename Y> struct Inner<T, Y>;
3207 // template<typename Y> struct Inner<U, Y>;
3210 // Outer<int, int> outer; // error: the partial specializations of Inner
3211 // // have the same signature.
3212 SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
3213 << WrittenTy->getType();
3214 SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
3215 << SemaRef.Context.getTypeDeclType(PrevDecl);
3220 // Create the class template partial specialization declaration.
3221 ClassTemplatePartialSpecializationDecl *InstPartialSpec
3222 = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
3223 PartialSpec->getTagKind(),
3225 PartialSpec->getLocStart(),
3226 PartialSpec->getLocation(),
3233 // Substitute the nested name specifier, if any.
3234 if (SubstQualifier(PartialSpec, InstPartialSpec))
3237 InstPartialSpec->setInstantiatedFromMember(PartialSpec);
3238 InstPartialSpec->setTypeAsWritten(WrittenTy);
3240 // Check the completed partial specialization.
3241 SemaRef.CheckTemplatePartialSpecialization(InstPartialSpec);
3243 // Add this partial specialization to the set of class template partial
3245 ClassTemplate->AddPartialSpecialization(InstPartialSpec,
3246 /*InsertPos=*/nullptr);
3247 return InstPartialSpec;
3250 /// \brief Instantiate the declaration of a variable template partial
3253 /// \param VarTemplate the (instantiated) variable template that is partially
3254 /// specialized by the instantiation of \p PartialSpec.
3256 /// \param PartialSpec the (uninstantiated) variable template partial
3257 /// specialization that we are instantiating.
3259 /// \returns The instantiated partial specialization, if successful; otherwise,
3260 /// NULL to indicate an error.
3261 VarTemplatePartialSpecializationDecl *
3262 TemplateDeclInstantiator::InstantiateVarTemplatePartialSpecialization(
3263 VarTemplateDecl *VarTemplate,
3264 VarTemplatePartialSpecializationDecl *PartialSpec) {
3265 // Create a local instantiation scope for this variable template partial
3266 // specialization, which will contain the instantiations of the template
3268 LocalInstantiationScope Scope(SemaRef);
3270 // Substitute into the template parameters of the variable template partial
3272 TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
3273 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
3277 // Substitute into the template arguments of the variable template partial
3279 const ASTTemplateArgumentListInfo *TemplArgInfo
3280 = PartialSpec->getTemplateArgsAsWritten();
3281 TemplateArgumentListInfo InstTemplateArgs(TemplArgInfo->LAngleLoc,
3282 TemplArgInfo->RAngleLoc);
3283 if (SemaRef.Subst(TemplArgInfo->getTemplateArgs(),
3284 TemplArgInfo->NumTemplateArgs,
3285 InstTemplateArgs, TemplateArgs))
3288 // Check that the template argument list is well-formed for this
3290 SmallVector<TemplateArgument, 4> Converted;
3291 if (SemaRef.CheckTemplateArgumentList(VarTemplate, PartialSpec->getLocation(),
3292 InstTemplateArgs, false, Converted))
3295 // Check these arguments are valid for a template partial specialization.
3296 if (SemaRef.CheckTemplatePartialSpecializationArgs(
3297 PartialSpec->getLocation(), VarTemplate, InstTemplateArgs.size(),
3301 // Figure out where to insert this variable template partial specialization
3302 // in the member template's set of variable template partial specializations.
3303 void *InsertPos = nullptr;
3304 VarTemplateSpecializationDecl *PrevDecl =
3305 VarTemplate->findPartialSpecialization(Converted, InsertPos);
3307 // Build the canonical type that describes the converted template
3308 // arguments of the variable template partial specialization.
3309 QualType CanonType = SemaRef.Context.getTemplateSpecializationType(
3310 TemplateName(VarTemplate), Converted);
3312 // Build the fully-sugared type for this variable template
3313 // specialization as the user wrote in the specialization
3314 // itself. This means that we'll pretty-print the type retrieved
3315 // from the specialization's declaration the way that the user
3316 // actually wrote the specialization, rather than formatting the
3317 // name based on the "canonical" representation used to store the
3318 // template arguments in the specialization.
3319 TypeSourceInfo *WrittenTy = SemaRef.Context.getTemplateSpecializationTypeInfo(
3320 TemplateName(VarTemplate), PartialSpec->getLocation(), InstTemplateArgs,
3324 // We've already seen a partial specialization with the same template
3325 // parameters and template arguments. This can happen, for example, when
3326 // substituting the outer template arguments ends up causing two
3327 // variable template partial specializations of a member variable template
3328 // to have identical forms, e.g.,
3330 // template<typename T, typename U>
3332 // template<typename X, typename Y> pair<X,Y> p;
3333 // template<typename Y> pair<T, Y> p;
3334 // template<typename Y> pair<U, Y> p;
3337 // Outer<int, int> outer; // error: the partial specializations of Inner
3338 // // have the same signature.
3339 SemaRef.Diag(PartialSpec->getLocation(),
3340 diag::err_var_partial_spec_redeclared)
3341 << WrittenTy->getType();
3342 SemaRef.Diag(PrevDecl->getLocation(),
3343 diag::note_var_prev_partial_spec_here);
3347 // Do substitution on the type of the declaration
3348 TypeSourceInfo *DI = SemaRef.SubstType(
3349 PartialSpec->getTypeSourceInfo(), TemplateArgs,
3350 PartialSpec->getTypeSpecStartLoc(), PartialSpec->getDeclName());
3354 if (DI->getType()->isFunctionType()) {
3355 SemaRef.Diag(PartialSpec->getLocation(),
3356 diag::err_variable_instantiates_to_function)
3357 << PartialSpec->isStaticDataMember() << DI->getType();
3361 // Create the variable template partial specialization declaration.
3362 VarTemplatePartialSpecializationDecl *InstPartialSpec =
3363 VarTemplatePartialSpecializationDecl::Create(
3364 SemaRef.Context, Owner, PartialSpec->getInnerLocStart(),
3365 PartialSpec->getLocation(), InstParams, VarTemplate, DI->getType(),
3366 DI, PartialSpec->getStorageClass(), Converted, InstTemplateArgs);
3368 // Substitute the nested name specifier, if any.
3369 if (SubstQualifier(PartialSpec, InstPartialSpec))
3372 InstPartialSpec->setInstantiatedFromMember(PartialSpec);
3373 InstPartialSpec->setTypeAsWritten(WrittenTy);
3375 // Check the completed partial specialization.
3376 SemaRef.CheckTemplatePartialSpecialization(InstPartialSpec);
3378 // Add this partial specialization to the set of variable template partial
3379 // specializations. The instantiation of the initializer is not necessary.
3380 VarTemplate->AddPartialSpecialization(InstPartialSpec, /*InsertPos=*/nullptr);
3382 SemaRef.BuildVariableInstantiation(InstPartialSpec, PartialSpec, TemplateArgs,
3383 LateAttrs, Owner, StartingScope);
3385 return InstPartialSpec;
3389 TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
3390 SmallVectorImpl<ParmVarDecl *> &Params) {
3391 TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
3392 assert(OldTInfo && "substituting function without type source info");
3393 assert(Params.empty() && "parameter vector is non-empty at start");
3395 CXXRecordDecl *ThisContext = nullptr;
3396 unsigned ThisTypeQuals = 0;
3397 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
3398 ThisContext = cast<CXXRecordDecl>(Owner);
3399 ThisTypeQuals = Method->getTypeQualifiers();
3402 TypeSourceInfo *NewTInfo
3403 = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
3404 D->getTypeSpecStartLoc(),
3406 ThisContext, ThisTypeQuals);
3410 TypeLoc OldTL = OldTInfo->getTypeLoc().IgnoreParens();
3411 if (FunctionProtoTypeLoc OldProtoLoc = OldTL.getAs<FunctionProtoTypeLoc>()) {
3412 if (NewTInfo != OldTInfo) {
3413 // Get parameters from the new type info.
3414 TypeLoc NewTL = NewTInfo->getTypeLoc().IgnoreParens();
3415 FunctionProtoTypeLoc NewProtoLoc = NewTL.castAs<FunctionProtoTypeLoc>();
3416 unsigned NewIdx = 0;
3417 for (unsigned OldIdx = 0, NumOldParams = OldProtoLoc.getNumParams();
3418 OldIdx != NumOldParams; ++OldIdx) {
3419 ParmVarDecl *OldParam = OldProtoLoc.getParam(OldIdx);
3420 LocalInstantiationScope *Scope = SemaRef.CurrentInstantiationScope;
3422 Optional<unsigned> NumArgumentsInExpansion;
3423 if (OldParam->isParameterPack())
3424 NumArgumentsInExpansion =
3425 SemaRef.getNumArgumentsInExpansion(OldParam->getType(),
3427 if (!NumArgumentsInExpansion) {
3428 // Simple case: normal parameter, or a parameter pack that's
3429 // instantiated to a (still-dependent) parameter pack.
3430 ParmVarDecl *NewParam = NewProtoLoc.getParam(NewIdx++);
3431 Params.push_back(NewParam);
3432 Scope->InstantiatedLocal(OldParam, NewParam);
3434 // Parameter pack expansion: make the instantiation an argument pack.
3435 Scope->MakeInstantiatedLocalArgPack(OldParam);
3436 for (unsigned I = 0; I != *NumArgumentsInExpansion; ++I) {
3437 ParmVarDecl *NewParam = NewProtoLoc.getParam(NewIdx++);
3438 Params.push_back(NewParam);
3439 Scope->InstantiatedLocalPackArg(OldParam, NewParam);
3444 // The function type itself was not dependent and therefore no
3445 // substitution occurred. However, we still need to instantiate
3446 // the function parameters themselves.
3447 const FunctionProtoType *OldProto =
3448 cast<FunctionProtoType>(OldProtoLoc.getType());
3449 for (unsigned i = 0, i_end = OldProtoLoc.getNumParams(); i != i_end;
3451 ParmVarDecl *OldParam = OldProtoLoc.getParam(i);
3453 Params.push_back(SemaRef.BuildParmVarDeclForTypedef(
3454 D, D->getLocation(), OldProto->getParamType(i)));
3459 cast_or_null<ParmVarDecl>(VisitParmVarDecl(OldParam));
3462 Params.push_back(Parm);
3466 // If the type of this function, after ignoring parentheses, is not
3467 // *directly* a function type, then we're instantiating a function that
3468 // was declared via a typedef or with attributes, e.g.,
3470 // typedef int functype(int, int);
3472 // int __cdecl meth(int, int);
3474 // In this case, we'll just go instantiate the ParmVarDecls that we
3475 // synthesized in the method declaration.
3476 SmallVector<QualType, 4> ParamTypes;
3477 Sema::ExtParameterInfoBuilder ExtParamInfos;
3478 if (SemaRef.SubstParmTypes(D->getLocation(), D->parameters(), nullptr,
3479 TemplateArgs, ParamTypes, &Params,
3487 /// Introduce the instantiated function parameters into the local
3488 /// instantiation scope, and set the parameter names to those used
3489 /// in the template.
3490 static bool addInstantiatedParametersToScope(Sema &S, FunctionDecl *Function,
3491 const FunctionDecl *PatternDecl,
3492 LocalInstantiationScope &Scope,
3493 const MultiLevelTemplateArgumentList &TemplateArgs) {
3494 unsigned FParamIdx = 0;
3495 for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
3496 const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
3497 if (!PatternParam->isParameterPack()) {
3498 // Simple case: not a parameter pack.
3499 assert(FParamIdx < Function->getNumParams());
3500 ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
3501 FunctionParam->setDeclName(PatternParam->getDeclName());
3502 // If the parameter's type is not dependent, update it to match the type
3503 // in the pattern. They can differ in top-level cv-qualifiers, and we want
3504 // the pattern's type here. If the type is dependent, they can't differ,
3505 // per core issue 1668. Substitute into the type from the pattern, in case
3506 // it's instantiation-dependent.
3507 // FIXME: Updating the type to work around this is at best fragile.
3508 if (!PatternDecl->getType()->isDependentType()) {
3509 QualType T = S.SubstType(PatternParam->getType(), TemplateArgs,
3510 FunctionParam->getLocation(),
3511 FunctionParam->getDeclName());
3514 FunctionParam->setType(T);
3517 Scope.InstantiatedLocal(PatternParam, FunctionParam);
3522 // Expand the parameter pack.
3523 Scope.MakeInstantiatedLocalArgPack(PatternParam);
3524 Optional<unsigned> NumArgumentsInExpansion
3525 = S.getNumArgumentsInExpansion(PatternParam->getType(), TemplateArgs);
3526 assert(NumArgumentsInExpansion &&
3527 "should only be called when all template arguments are known");
3528 QualType PatternType =
3529 PatternParam->getType()->castAs<PackExpansionType>()->getPattern();
3530 for (unsigned Arg = 0; Arg < *NumArgumentsInExpansion; ++Arg) {
3531 ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
3532 FunctionParam->setDeclName(PatternParam->getDeclName());
3533 if (!PatternDecl->getType()->isDependentType()) {
3534 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, Arg);
3535 QualType T = S.SubstType(PatternType, TemplateArgs,
3536 FunctionParam->getLocation(),
3537 FunctionParam->getDeclName());
3540 FunctionParam->setType(T);
3543 Scope.InstantiatedLocalPackArg(PatternParam, FunctionParam);
3551 void Sema::InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
3552 FunctionDecl *Decl) {
3553 const FunctionProtoType *Proto = Decl->getType()->castAs<FunctionProtoType>();
3554 if (Proto->getExceptionSpecType() != EST_Uninstantiated)
3557 InstantiatingTemplate Inst(*this, PointOfInstantiation, Decl,
3558 InstantiatingTemplate::ExceptionSpecification());
3559 if (Inst.isInvalid()) {
3560 // We hit the instantiation depth limit. Clear the exception specification
3561 // so that our callers don't have to cope with EST_Uninstantiated.
3562 UpdateExceptionSpec(Decl, EST_None);
3565 if (Inst.isAlreadyInstantiating()) {
3566 // This exception specification indirectly depends on itself. Reject.
3567 // FIXME: Corresponding rule in the standard?
3568 Diag(PointOfInstantiation, diag::err_exception_spec_cycle) << Decl;
3569 UpdateExceptionSpec(Decl, EST_None);
3573 // Enter the scope of this instantiation. We don't use
3574 // PushDeclContext because we don't have a scope.
3575 Sema::ContextRAII savedContext(*this, Decl);
3576 LocalInstantiationScope Scope(*this);
3578 MultiLevelTemplateArgumentList TemplateArgs =
3579 getTemplateInstantiationArgs(Decl, nullptr, /*RelativeToPrimary*/true);
3581 FunctionDecl *Template = Proto->getExceptionSpecTemplate();
3582 if (addInstantiatedParametersToScope(*this, Decl, Template, Scope,
3584 UpdateExceptionSpec(Decl, EST_None);
3588 SubstExceptionSpec(Decl, Template->getType()->castAs<FunctionProtoType>(),
3592 /// \brief Initializes the common fields of an instantiation function
3593 /// declaration (New) from the corresponding fields of its template (Tmpl).
3595 /// \returns true if there was an error
3597 TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
3598 FunctionDecl *Tmpl) {
3599 if (Tmpl->isDeleted())
3600 New->setDeletedAsWritten();
3602 New->setImplicit(Tmpl->isImplicit());
3604 // Forward the mangling number from the template to the instantiated decl.
3605 SemaRef.Context.setManglingNumber(New,
3606 SemaRef.Context.getManglingNumber(Tmpl));
3608 // If we are performing substituting explicitly-specified template arguments
3609 // or deduced template arguments into a function template and we reach this
3610 // point, we are now past the point where SFINAE applies and have committed
3611 // to keeping the new function template specialization. We therefore
3612 // convert the active template instantiation for the function template
3613 // into a template instantiation for this specific function template
3614 // specialization, which is not a SFINAE context, so that we diagnose any
3615 // further errors in the declaration itself.
3616 typedef Sema::CodeSynthesisContext ActiveInstType;
3617 ActiveInstType &ActiveInst = SemaRef.CodeSynthesisContexts.back();
3618 if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
3619 ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
3620 if (FunctionTemplateDecl *FunTmpl
3621 = dyn_cast<FunctionTemplateDecl>(ActiveInst.Entity)) {
3622 assert(FunTmpl->getTemplatedDecl() == Tmpl &&
3623 "Deduction from the wrong function template?");
3625 ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
3626 ActiveInst.Entity = New;
3630 const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
3631 assert(Proto && "Function template without prototype?");
3633 if (Proto->hasExceptionSpec() || Proto->getNoReturnAttr()) {
3634 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
3636 // DR1330: In C++11, defer instantiation of a non-trivial
3637 // exception specification.
3638 // DR1484: Local classes and their members are instantiated along with the
3639 // containing function.
3640 if (SemaRef.getLangOpts().CPlusPlus11 &&
3641 EPI.ExceptionSpec.Type != EST_None &&
3642 EPI.ExceptionSpec.Type != EST_DynamicNone &&
3643 EPI.ExceptionSpec.Type != EST_BasicNoexcept &&
3644 !Tmpl->isLexicallyWithinFunctionOrMethod()) {
3645 FunctionDecl *ExceptionSpecTemplate = Tmpl;
3646 if (EPI.ExceptionSpec.Type == EST_Uninstantiated)
3647 ExceptionSpecTemplate = EPI.ExceptionSpec.SourceTemplate;
3648 ExceptionSpecificationType NewEST = EST_Uninstantiated;
3649 if (EPI.ExceptionSpec.Type == EST_Unevaluated)
3650 NewEST = EST_Unevaluated;
3652 // Mark the function has having an uninstantiated exception specification.
3653 const FunctionProtoType *NewProto
3654 = New->getType()->getAs<FunctionProtoType>();
3655 assert(NewProto && "Template instantiation without function prototype?");
3656 EPI = NewProto->getExtProtoInfo();
3657 EPI.ExceptionSpec.Type = NewEST;
3658 EPI.ExceptionSpec.SourceDecl = New;
3659 EPI.ExceptionSpec.SourceTemplate = ExceptionSpecTemplate;
3660 New->setType(SemaRef.Context.getFunctionType(
3661 NewProto->getReturnType(), NewProto->getParamTypes(), EPI));
3663 SemaRef.SubstExceptionSpec(New, Proto, TemplateArgs);
3667 // Get the definition. Leaves the variable unchanged if undefined.
3668 const FunctionDecl *Definition = Tmpl;
3669 Tmpl->isDefined(Definition);
3671 SemaRef.InstantiateAttrs(TemplateArgs, Definition, New,
3672 LateAttrs, StartingScope);
3677 /// \brief Initializes common fields of an instantiated method
3678 /// declaration (New) from the corresponding fields of its template
3681 /// \returns true if there was an error
3683 TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
3684 CXXMethodDecl *Tmpl) {
3685 if (InitFunctionInstantiation(New, Tmpl))
3688 New->setAccess(Tmpl->getAccess());
3689 if (Tmpl->isVirtualAsWritten())
3690 New->setVirtualAsWritten(true);
3692 // FIXME: New needs a pointer to Tmpl
3696 /// In the MS ABI, we need to instantiate default arguments of dllexported
3697 /// default constructors along with the constructor definition. This allows IR
3698 /// gen to emit a constructor closure which calls the default constructor with
3699 /// its default arguments.
3700 static void InstantiateDefaultCtorDefaultArgs(Sema &S,
3701 CXXConstructorDecl *Ctor) {
3702 assert(S.Context.getTargetInfo().getCXXABI().isMicrosoft() &&
3703 Ctor->isDefaultConstructor());
3704 unsigned NumParams = Ctor->getNumParams();
3707 DLLExportAttr *Attr = Ctor->getAttr<DLLExportAttr>();
3710 for (unsigned I = 0; I != NumParams; ++I) {
3711 (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), Ctor,
3712 Ctor->getParamDecl(I));
3713 S.DiscardCleanupsInEvaluationContext();
3717 /// \brief Instantiate the definition of the given function from its
3720 /// \param PointOfInstantiation the point at which the instantiation was
3721 /// required. Note that this is not precisely a "point of instantiation"
3722 /// for the function, but it's close.
3724 /// \param Function the already-instantiated declaration of a
3725 /// function template specialization or member function of a class template
3728 /// \param Recursive if true, recursively instantiates any functions that
3729 /// are required by this instantiation.
3731 /// \param DefinitionRequired if true, then we are performing an explicit
3732 /// instantiation where the body of the function is required. Complain if
3733 /// there is no such body.
3734 void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
3735 FunctionDecl *Function,
3737 bool DefinitionRequired,
3739 if (Function->isInvalidDecl() || Function->isDefined())
3742 // Never instantiate an explicit specialization except if it is a class scope
3743 // explicit specialization.
3744 TemplateSpecializationKind TSK = Function->getTemplateSpecializationKind();
3745 if (TSK == TSK_ExplicitSpecialization &&
3746 !Function->getClassScopeSpecializationPattern())
3749 // Find the function body that we'll be substituting.
3750 const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
3751 assert(PatternDecl && "instantiating a non-template");
3753 const FunctionDecl *PatternDef = PatternDecl->getDefinition();
3754 Stmt *Pattern = nullptr;
3756 Pattern = PatternDef->getBody(PatternDef);
3757 PatternDecl = PatternDef;
3760 // FIXME: We need to track the instantiation stack in order to know which
3761 // definitions should be visible within this instantiation.
3762 if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Function,
3763 Function->getInstantiatedFromMemberFunction(),
3764 PatternDecl, PatternDef, TSK,
3765 /*Complain*/DefinitionRequired)) {
3766 if (DefinitionRequired)
3767 Function->setInvalidDecl();
3768 else if (TSK == TSK_ExplicitInstantiationDefinition) {
3769 // Try again at the end of the translation unit (at which point a
3770 // definition will be required).
3772 PendingInstantiations.push_back(
3773 std::make_pair(Function, PointOfInstantiation));
3774 } else if (TSK == TSK_ImplicitInstantiation) {
3775 if (AtEndOfTU && !getDiagnostics().hasErrorOccurred()) {
3776 Diag(PointOfInstantiation, diag::warn_func_template_missing)
3778 Diag(PatternDecl->getLocation(), diag::note_forward_template_decl);
3779 if (getLangOpts().CPlusPlus11)
3780 Diag(PointOfInstantiation, diag::note_inst_declaration_hint)
3788 // Postpone late parsed template instantiations.
3789 if (PatternDecl->isLateTemplateParsed() &&
3790 !LateTemplateParser) {
3791 PendingInstantiations.push_back(
3792 std::make_pair(Function, PointOfInstantiation));
3796 // If we're performing recursive template instantiation, create our own
3797 // queue of pending implicit instantiations that we will instantiate later,
3798 // while we're still within our own instantiation context.
3799 // This has to happen before LateTemplateParser below is called, so that
3800 // it marks vtables used in late parsed templates as used.
3801 SavePendingLocalImplicitInstantiationsRAII
3802 SavedPendingLocalImplicitInstantiations(*this);
3803 SavePendingInstantiationsAndVTableUsesRAII
3804 SavePendingInstantiationsAndVTableUses(*this, /*Enabled=*/Recursive);
3806 // Call the LateTemplateParser callback if there is a need to late parse
3807 // a templated function definition.
3808 if (!Pattern && PatternDecl->isLateTemplateParsed() &&
3809 LateTemplateParser) {
3810 // FIXME: Optimize to allow individual templates to be deserialized.
3811 if (PatternDecl->isFromASTFile())
3812 ExternalSource->ReadLateParsedTemplates(LateParsedTemplateMap);
3814 auto LPTIter = LateParsedTemplateMap.find(PatternDecl);
3815 assert(LPTIter != LateParsedTemplateMap.end() &&
3816 "missing LateParsedTemplate");
3817 LateTemplateParser(OpaqueParser, *LPTIter->second);
3818 Pattern = PatternDecl->getBody(PatternDecl);
3821 // Note, we should never try to instantiate a deleted function template.
3822 assert((Pattern || PatternDecl->isDefaulted()) &&
3823 "unexpected kind of function template definition");
3825 // C++1y [temp.explicit]p10:
3826 // Except for inline functions, declarations with types deduced from their
3827 // initializer or return value, and class template specializations, other
3828 // explicit instantiation declarations have the effect of suppressing the
3829 // implicit instantiation of the entity to which they refer.
3830 if (TSK == TSK_ExplicitInstantiationDeclaration &&
3831 !PatternDecl->isInlined() &&
3832 !PatternDecl->getReturnType()->getContainedAutoType())
3835 if (PatternDecl->isInlined()) {
3836 // Function, and all later redeclarations of it (from imported modules,
3837 // for instance), are now implicitly inline.
3838 for (auto *D = Function->getMostRecentDecl(); /**/;
3839 D = D->getPreviousDecl()) {
3840 D->setImplicitlyInline();
3846 InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
3847 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
3849 PrettyDeclStackTraceEntry CrashInfo(*this, Function, SourceLocation(),
3850 "instantiating function definition");
3852 // The instantiation is visible here, even if it was first declared in an
3853 // unimported module.
3854 Function->setHidden(false);
3856 // Copy the inner loc start from the pattern.
3857 Function->setInnerLocStart(PatternDecl->getInnerLocStart());
3859 EnterExpressionEvaluationContext EvalContext(
3860 *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
3862 // Introduce a new scope where local variable instantiations will be
3863 // recorded, unless we're actually a member function within a local
3864 // class, in which case we need to merge our results with the parent
3865 // scope (of the enclosing function).
3866 bool MergeWithParentScope = false;
3867 if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
3868 MergeWithParentScope = Rec->isLocalClass();
3870 LocalInstantiationScope Scope(*this, MergeWithParentScope);
3872 if (PatternDecl->isDefaulted())
3873 SetDeclDefaulted(Function, PatternDecl->getLocation());
3875 MultiLevelTemplateArgumentList TemplateArgs =
3876 getTemplateInstantiationArgs(Function, nullptr, false, PatternDecl);
3878 // Substitute into the qualifier; we can get a substitution failure here
3879 // through evil use of alias templates.
3880 // FIXME: Is CurContext correct for this? Should we go to the (instantiation
3881 // of the) lexical context of the pattern?
3882 SubstQualifier(*this, PatternDecl, Function, TemplateArgs);
3884 ActOnStartOfFunctionDef(nullptr, Function);
3886 // Enter the scope of this instantiation. We don't use
3887 // PushDeclContext because we don't have a scope.
3888 Sema::ContextRAII savedContext(*this, Function);
3890 if (addInstantiatedParametersToScope(*this, Function, PatternDecl, Scope,
3894 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Function)) {
3895 // If this is a constructor, instantiate the member initializers.
3896 InstantiateMemInitializers(Ctor, cast<CXXConstructorDecl>(PatternDecl),
3899 // If this is an MS ABI dllexport default constructor, instantiate any
3900 // default arguments.
3901 if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
3902 Ctor->isDefaultConstructor()) {
3903 InstantiateDefaultCtorDefaultArgs(*this, Ctor);
3907 // Instantiate the function body.
3908 StmtResult Body = SubstStmt(Pattern, TemplateArgs);
3910 if (Body.isInvalid())
3911 Function->setInvalidDecl();
3913 // FIXME: finishing the function body while in an expression evaluation
3914 // context seems wrong. Investigate more.
3915 ActOnFinishFunctionBody(Function, Body.get(),
3916 /*IsInstantiation=*/true);
3918 PerformDependentDiagnostics(PatternDecl, TemplateArgs);
3920 if (auto *Listener = getASTMutationListener())
3921 Listener->FunctionDefinitionInstantiated(Function);
3926 DeclGroupRef DG(Function);
3927 Consumer.HandleTopLevelDecl(DG);
3929 // This class may have local implicit instantiations that need to be
3930 // instantiation within this scope.
3931 PerformPendingInstantiations(/*LocalOnly=*/true);
3935 // Define any pending vtables.
3936 DefineUsedVTables();
3938 // Instantiate any pending implicit instantiations found during the
3939 // instantiation of this template.
3940 PerformPendingInstantiations();
3942 // PendingInstantiations and VTableUses are restored through
3943 // SavePendingInstantiationsAndVTableUses's destructor.
3947 VarTemplateSpecializationDecl *Sema::BuildVarTemplateInstantiation(
3948 VarTemplateDecl *VarTemplate, VarDecl *FromVar,
3949 const TemplateArgumentList &TemplateArgList,
3950 const TemplateArgumentListInfo &TemplateArgsInfo,
3951 SmallVectorImpl<TemplateArgument> &Converted,
3952 SourceLocation PointOfInstantiation, void *InsertPos,
3953 LateInstantiatedAttrVec *LateAttrs,
3954 LocalInstantiationScope *StartingScope) {
3955 if (FromVar->isInvalidDecl())
3958 InstantiatingTemplate Inst(*this, PointOfInstantiation, FromVar);
3959 if (Inst.isInvalid())
3962 MultiLevelTemplateArgumentList TemplateArgLists;
3963 TemplateArgLists.addOuterTemplateArguments(&TemplateArgList);
3965 // Instantiate the first declaration of the variable template: for a partial
3966 // specialization of a static data member template, the first declaration may
3967 // or may not be the declaration in the class; if it's in the class, we want
3968 // to instantiate a member in the class (a declaration), and if it's outside,
3969 // we want to instantiate a definition.
3971 // If we're instantiating an explicitly-specialized member template or member
3972 // partial specialization, don't do this. The member specialization completely
3973 // replaces the original declaration in this case.
3974 bool IsMemberSpec = false;
3975 if (VarTemplatePartialSpecializationDecl *PartialSpec =
3976 dyn_cast<VarTemplatePartialSpecializationDecl>(FromVar))
3977 IsMemberSpec = PartialSpec->isMemberSpecialization();
3978 else if (VarTemplateDecl *FromTemplate = FromVar->getDescribedVarTemplate())
3979 IsMemberSpec = FromTemplate->isMemberSpecialization();
3981 FromVar = FromVar->getFirstDecl();
3983 MultiLevelTemplateArgumentList MultiLevelList(TemplateArgList);
3984 TemplateDeclInstantiator Instantiator(*this, FromVar->getDeclContext(),
3987 // TODO: Set LateAttrs and StartingScope ...
3989 return cast_or_null<VarTemplateSpecializationDecl>(
3990 Instantiator.VisitVarTemplateSpecializationDecl(
3991 VarTemplate, FromVar, InsertPos, TemplateArgsInfo, Converted));
3994 /// \brief Instantiates a variable template specialization by completing it
3995 /// with appropriate type information and initializer.
3996 VarTemplateSpecializationDecl *Sema::CompleteVarTemplateSpecializationDecl(
3997 VarTemplateSpecializationDecl *VarSpec, VarDecl *PatternDecl,
3998 const MultiLevelTemplateArgumentList &TemplateArgs) {
4000 // Do substitution on the type of the declaration
4001 TypeSourceInfo *DI =
4002 SubstType(PatternDecl->getTypeSourceInfo(), TemplateArgs,
4003 PatternDecl->getTypeSpecStartLoc(), PatternDecl->getDeclName());
4007 // Update the type of this variable template specialization.
4008 VarSpec->setType(DI->getType());
4010 // Instantiate the initializer.
4011 InstantiateVariableInitializer(VarSpec, PatternDecl, TemplateArgs);
4016 /// BuildVariableInstantiation - Used after a new variable has been created.
4017 /// Sets basic variable data and decides whether to postpone the
4018 /// variable instantiation.
4019 void Sema::BuildVariableInstantiation(
4020 VarDecl *NewVar, VarDecl *OldVar,
4021 const MultiLevelTemplateArgumentList &TemplateArgs,
4022 LateInstantiatedAttrVec *LateAttrs, DeclContext *Owner,
4023 LocalInstantiationScope *StartingScope,
4024 bool InstantiatingVarTemplate) {
4026 // If we are instantiating a local extern declaration, the
4027 // instantiation belongs lexically to the containing function.
4028 // If we are instantiating a static data member defined
4029 // out-of-line, the instantiation will have the same lexical
4030 // context (which will be a namespace scope) as the template.
4031 if (OldVar->isLocalExternDecl()) {
4032 NewVar->setLocalExternDecl();
4033 NewVar->setLexicalDeclContext(Owner);
4034 } else if (OldVar->isOutOfLine())
4035 NewVar->setLexicalDeclContext(OldVar->getLexicalDeclContext());
4036 NewVar->setTSCSpec(OldVar->getTSCSpec());
4037 NewVar->setInitStyle(OldVar->getInitStyle());
4038 NewVar->setCXXForRangeDecl(OldVar->isCXXForRangeDecl());
4039 NewVar->setConstexpr(OldVar->isConstexpr());
4040 NewVar->setInitCapture(OldVar->isInitCapture());
4041 NewVar->setPreviousDeclInSameBlockScope(
4042 OldVar->isPreviousDeclInSameBlockScope());
4043 NewVar->setAccess(OldVar->getAccess());
4045 if (!OldVar->isStaticDataMember()) {
4046 if (OldVar->isUsed(false))
4047 NewVar->setIsUsed();
4048 NewVar->setReferenced(OldVar->isReferenced());
4051 InstantiateAttrs(TemplateArgs, OldVar, NewVar, LateAttrs, StartingScope);
4053 LookupResult Previous(
4054 *this, NewVar->getDeclName(), NewVar->getLocation(),
4055 NewVar->isLocalExternDecl() ? Sema::LookupRedeclarationWithLinkage
4056 : Sema::LookupOrdinaryName,
4057 Sema::ForRedeclaration);
4059 if (NewVar->isLocalExternDecl() && OldVar->getPreviousDecl() &&
4060 (!OldVar->getPreviousDecl()->getDeclContext()->isDependentContext() ||
4061 OldVar->getPreviousDecl()->getDeclContext()==OldVar->getDeclContext())) {
4062 // We have a previous declaration. Use that one, so we merge with the
4064 if (NamedDecl *NewPrev = FindInstantiatedDecl(
4065 NewVar->getLocation(), OldVar->getPreviousDecl(), TemplateArgs))
4066 Previous.addDecl(NewPrev);
4067 } else if (!isa<VarTemplateSpecializationDecl>(NewVar) &&
4068 OldVar->hasLinkage())
4069 LookupQualifiedName(Previous, NewVar->getDeclContext(), false);
4070 CheckVariableDeclaration(NewVar, Previous);
4072 if (!InstantiatingVarTemplate) {
4073 NewVar->getLexicalDeclContext()->addHiddenDecl(NewVar);
4074 if (!NewVar->isLocalExternDecl() || !NewVar->getPreviousDecl())
4075 NewVar->getDeclContext()->makeDeclVisibleInContext(NewVar);
4078 if (!OldVar->isOutOfLine()) {
4079 if (NewVar->getDeclContext()->isFunctionOrMethod())
4080 CurrentInstantiationScope->InstantiatedLocal(OldVar, NewVar);
4083 // Link instantiations of static data members back to the template from
4084 // which they were instantiated.
4085 if (NewVar->isStaticDataMember() && !InstantiatingVarTemplate)
4086 NewVar->setInstantiationOfStaticDataMember(OldVar,
4087 TSK_ImplicitInstantiation);
4089 // Forward the mangling number from the template to the instantiated decl.
4090 Context.setManglingNumber(NewVar, Context.getManglingNumber(OldVar));
4091 Context.setStaticLocalNumber(NewVar, Context.getStaticLocalNumber(OldVar));
4093 // Delay instantiation of the initializer for variable templates or inline
4094 // static data members until a definition of the variable is needed. We need
4095 // it right away if the type contains 'auto'.
4096 if ((!isa<VarTemplateSpecializationDecl>(NewVar) &&
4097 !InstantiatingVarTemplate &&
4098 !(OldVar->isInline() && OldVar->isThisDeclarationADefinition())) ||
4099 NewVar->getType()->isUndeducedType())
4100 InstantiateVariableInitializer(NewVar, OldVar, TemplateArgs);
4102 // Diagnose unused local variables with dependent types, where the diagnostic
4103 // will have been deferred.
4104 if (!NewVar->isInvalidDecl() &&
4105 NewVar->getDeclContext()->isFunctionOrMethod() &&
4106 OldVar->getType()->isDependentType())
4107 DiagnoseUnusedDecl(NewVar);
4110 /// \brief Instantiate the initializer of a variable.
4111 void Sema::InstantiateVariableInitializer(
4112 VarDecl *Var, VarDecl *OldVar,
4113 const MultiLevelTemplateArgumentList &TemplateArgs) {
4114 // We propagate the 'inline' flag with the initializer, because it
4115 // would otherwise imply that the variable is a definition for a
4116 // non-static data member.
4117 if (OldVar->isInlineSpecified())
4118 Var->setInlineSpecified();
4119 else if (OldVar->isInline())
4120 Var->setImplicitlyInline();
4122 if (OldVar->getInit()) {
4123 if (Var->isStaticDataMember() && !OldVar->isOutOfLine())
4124 PushExpressionEvaluationContext(
4125 Sema::ExpressionEvaluationContext::ConstantEvaluated, OldVar);
4127 PushExpressionEvaluationContext(
4128 Sema::ExpressionEvaluationContext::PotentiallyEvaluated, OldVar);
4130 // Instantiate the initializer.
4134 ContextRAII SwitchContext(*this, Var->getDeclContext());
4135 Init = SubstInitializer(OldVar->getInit(), TemplateArgs,
4136 OldVar->getInitStyle() == VarDecl::CallInit);
4139 if (!Init.isInvalid()) {
4140 Expr *InitExpr = Init.get();
4142 if (Var->hasAttr<DLLImportAttr>() &&
4144 !InitExpr->isConstantInitializer(getASTContext(), false))) {
4145 // Do not dynamically initialize dllimport variables.
4146 } else if (InitExpr) {
4147 bool DirectInit = OldVar->isDirectInit();
4148 AddInitializerToDecl(Var, InitExpr, DirectInit);
4150 ActOnUninitializedDecl(Var);
4152 // FIXME: Not too happy about invalidating the declaration
4153 // because of a bogus initializer.
4154 Var->setInvalidDecl();
4157 PopExpressionEvaluationContext();
4159 if (Var->isStaticDataMember()) {
4160 if (!Var->isOutOfLine())
4163 // If the declaration inside the class had an initializer, don't add
4164 // another one to the out-of-line definition.
4165 if (OldVar->getFirstDecl()->hasInit())
4169 // We'll add an initializer to a for-range declaration later.
4170 if (Var->isCXXForRangeDecl())
4173 ActOnUninitializedDecl(Var);
4177 /// \brief Instantiate the definition of the given variable from its
4180 /// \param PointOfInstantiation the point at which the instantiation was
4181 /// required. Note that this is not precisely a "point of instantiation"
4182 /// for the function, but it's close.
4184 /// \param Var the already-instantiated declaration of a static member
4185 /// variable of a class template specialization.
4187 /// \param Recursive if true, recursively instantiates any functions that
4188 /// are required by this instantiation.
4190 /// \param DefinitionRequired if true, then we are performing an explicit
4191 /// instantiation where an out-of-line definition of the member variable
4192 /// is required. Complain if there is no such definition.
4193 void Sema::InstantiateStaticDataMemberDefinition(
4194 SourceLocation PointOfInstantiation,
4197 bool DefinitionRequired) {
4198 InstantiateVariableDefinition(PointOfInstantiation, Var, Recursive,
4199 DefinitionRequired);
4202 void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
4203 VarDecl *Var, bool Recursive,
4204 bool DefinitionRequired, bool AtEndOfTU) {
4205 if (Var->isInvalidDecl())
4208 VarTemplateSpecializationDecl *VarSpec =
4209 dyn_cast<VarTemplateSpecializationDecl>(Var);
4210 VarDecl *PatternDecl = nullptr, *Def = nullptr;
4211 MultiLevelTemplateArgumentList TemplateArgs =
4212 getTemplateInstantiationArgs(Var);
4215 // If this is a variable template specialization, make sure that it is
4216 // non-dependent, then find its instantiation pattern.
4217 bool InstantiationDependent = false;
4218 assert(!TemplateSpecializationType::anyDependentTemplateArguments(
4219 VarSpec->getTemplateArgsInfo(), InstantiationDependent) &&
4220 "Only instantiate variable template specializations that are "
4221 "not type-dependent");
4222 (void)InstantiationDependent;
4224 // Find the variable initialization that we'll be substituting. If the
4225 // pattern was instantiated from a member template, look back further to
4226 // find the real pattern.
4227 assert(VarSpec->getSpecializedTemplate() &&
4228 "Specialization without specialized template?");
4229 llvm::PointerUnion<VarTemplateDecl *,
4230 VarTemplatePartialSpecializationDecl *> PatternPtr =
4231 VarSpec->getSpecializedTemplateOrPartial();
4232 if (PatternPtr.is<VarTemplatePartialSpecializationDecl *>()) {
4233 VarTemplatePartialSpecializationDecl *Tmpl =
4234 PatternPtr.get<VarTemplatePartialSpecializationDecl *>();
4235 while (VarTemplatePartialSpecializationDecl *From =
4236 Tmpl->getInstantiatedFromMember()) {
4237 if (Tmpl->isMemberSpecialization())
4244 VarTemplateDecl *Tmpl = PatternPtr.get<VarTemplateDecl *>();
4245 while (VarTemplateDecl *From =
4246 Tmpl->getInstantiatedFromMemberTemplate()) {
4247 if (Tmpl->isMemberSpecialization())
4252 PatternDecl = Tmpl->getTemplatedDecl();
4255 // If this is a static data member template, there might be an
4256 // uninstantiated initializer on the declaration. If so, instantiate
4258 if (PatternDecl->isStaticDataMember() &&
4259 (PatternDecl = PatternDecl->getFirstDecl())->hasInit() &&
4261 // FIXME: Factor out the duplicated instantiation context setup/tear down
4263 InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
4264 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
4266 PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
4267 "instantiating variable initializer");
4269 // The instantiation is visible here, even if it was first declared in an
4270 // unimported module.
4271 Var->setHidden(false);
4273 // If we're performing recursive template instantiation, create our own
4274 // queue of pending implicit instantiations that we will instantiate
4275 // later, while we're still within our own instantiation context.
4276 SavePendingInstantiationsAndVTableUsesRAII
4277 SavePendingInstantiationsAndVTableUses(*this, /*Enabled=*/Recursive);
4279 LocalInstantiationScope Local(*this);
4281 // Enter the scope of this instantiation. We don't use
4282 // PushDeclContext because we don't have a scope.
4283 ContextRAII PreviousContext(*this, Var->getDeclContext());
4284 InstantiateVariableInitializer(Var, PatternDecl, TemplateArgs);
4285 PreviousContext.pop();
4287 // FIXME: Need to inform the ASTConsumer that we instantiated the
4290 // This variable may have local implicit instantiations that need to be
4291 // instantiated within this scope.
4292 PerformPendingInstantiations(/*LocalOnly=*/true);
4297 // Define any newly required vtables.
4298 DefineUsedVTables();
4300 // Instantiate any pending implicit instantiations found during the
4301 // instantiation of this template.
4302 PerformPendingInstantiations();
4304 // PendingInstantiations and VTableUses are restored through
4305 // SavePendingInstantiationsAndVTableUses's destructor.
4309 // Find actual definition
4310 Def = PatternDecl->getDefinition(getASTContext());
4312 // If this is a static data member, find its out-of-line definition.
4313 assert(Var->isStaticDataMember() && "not a static data member?");
4314 PatternDecl = Var->getInstantiatedFromStaticDataMember();
4316 assert(PatternDecl && "data member was not instantiated from a template?");
4317 assert(PatternDecl->isStaticDataMember() && "not a static data member?");
4318 Def = PatternDecl->getDefinition();
4321 TemplateSpecializationKind TSK = Var->getTemplateSpecializationKind();
4323 // If we don't have a definition of the variable template, we won't perform
4324 // any instantiation. Rather, we rely on the user to instantiate this
4325 // definition (or provide a specialization for it) in another translation
4327 if (!Def && !DefinitionRequired) {
4328 if (TSK == TSK_ExplicitInstantiationDefinition) {
4329 PendingInstantiations.push_back(
4330 std::make_pair(Var, PointOfInstantiation));
4331 } else if (TSK == TSK_ImplicitInstantiation) {
4332 // Warn about missing definition at the end of translation unit.
4333 if (AtEndOfTU && !getDiagnostics().hasErrorOccurred()) {
4334 Diag(PointOfInstantiation, diag::warn_var_template_missing)
4336 Diag(PatternDecl->getLocation(), diag::note_forward_template_decl);
4337 if (getLangOpts().CPlusPlus11)
4338 Diag(PointOfInstantiation, diag::note_inst_declaration_hint) << Var;
4345 // FIXME: We need to track the instantiation stack in order to know which
4346 // definitions should be visible within this instantiation.
4347 // FIXME: Produce diagnostics when Var->getInstantiatedFromStaticDataMember().
4348 if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Var,
4349 /*InstantiatedFromMember*/false,
4350 PatternDecl, Def, TSK,
4351 /*Complain*/DefinitionRequired))
4355 // Never instantiate an explicit specialization.
4356 if (TSK == TSK_ExplicitSpecialization)
4359 // C++11 [temp.explicit]p10:
4360 // Except for inline functions, [...] explicit instantiation declarations
4361 // have the effect of suppressing the implicit instantiation of the entity
4362 // to which they refer.
4363 if (TSK == TSK_ExplicitInstantiationDeclaration)
4366 // Make sure to pass the instantiated variable to the consumer at the end.
4367 struct PassToConsumerRAII {
4368 ASTConsumer &Consumer;
4371 PassToConsumerRAII(ASTConsumer &Consumer, VarDecl *Var)
4372 : Consumer(Consumer), Var(Var) { }
4374 ~PassToConsumerRAII() {
4375 Consumer.HandleCXXStaticMemberVarInstantiation(Var);
4377 } PassToConsumerRAII(Consumer, Var);
4379 // If we already have a definition, we're done.
4380 if (VarDecl *Def = Var->getDefinition()) {
4381 // We may be explicitly instantiating something we've already implicitly
4383 Def->setTemplateSpecializationKind(Var->getTemplateSpecializationKind(),
4384 PointOfInstantiation);
4388 InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
4389 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
4391 PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
4392 "instantiating variable definition");
4394 // If we're performing recursive template instantiation, create our own
4395 // queue of pending implicit instantiations that we will instantiate later,
4396 // while we're still within our own instantiation context.
4397 SavePendingLocalImplicitInstantiationsRAII
4398 SavedPendingLocalImplicitInstantiations(*this);
4399 SavePendingInstantiationsAndVTableUsesRAII
4400 SavePendingInstantiationsAndVTableUses(*this, /*Enabled=*/Recursive);
4402 // Enter the scope of this instantiation. We don't use
4403 // PushDeclContext because we don't have a scope.
4404 ContextRAII PreviousContext(*this, Var->getDeclContext());
4405 LocalInstantiationScope Local(*this);
4407 VarDecl *OldVar = Var;
4408 if (Def->isStaticDataMember() && !Def->isOutOfLine()) {
4409 // We're instantiating an inline static data member whose definition was
4410 // provided inside the class.
4411 // FIXME: Update record?
4412 InstantiateVariableInitializer(Var, Def, TemplateArgs);
4413 } else if (!VarSpec) {
4414 Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
4416 } else if (Var->isStaticDataMember() &&
4417 Var->getLexicalDeclContext()->isRecord()) {
4418 // We need to instantiate the definition of a static data member template,
4419 // and all we have is the in-class declaration of it. Instantiate a separate
4420 // declaration of the definition.
4421 TemplateDeclInstantiator Instantiator(*this, Var->getDeclContext(),
4423 Var = cast_or_null<VarDecl>(Instantiator.VisitVarTemplateSpecializationDecl(
4424 VarSpec->getSpecializedTemplate(), Def, nullptr,
4425 VarSpec->getTemplateArgsInfo(), VarSpec->getTemplateArgs().asArray()));
4427 llvm::PointerUnion<VarTemplateDecl *,
4428 VarTemplatePartialSpecializationDecl *> PatternPtr =
4429 VarSpec->getSpecializedTemplateOrPartial();
4430 if (VarTemplatePartialSpecializationDecl *Partial =
4431 PatternPtr.dyn_cast<VarTemplatePartialSpecializationDecl *>())
4432 cast<VarTemplateSpecializationDecl>(Var)->setInstantiationOf(
4433 Partial, &VarSpec->getTemplateInstantiationArgs());
4435 // Merge the definition with the declaration.
4436 LookupResult R(*this, Var->getDeclName(), Var->getLocation(),
4437 LookupOrdinaryName, ForRedeclaration);
4439 MergeVarDecl(Var, R);
4441 // Attach the initializer.
4442 InstantiateVariableInitializer(Var, Def, TemplateArgs);
4445 // Complete the existing variable's definition with an appropriately
4446 // substituted type and initializer.
4447 Var = CompleteVarTemplateSpecializationDecl(VarSpec, Def, TemplateArgs);
4449 PreviousContext.pop();
4452 PassToConsumerRAII.Var = Var;
4453 Var->setTemplateSpecializationKind(OldVar->getTemplateSpecializationKind(),
4454 OldVar->getPointOfInstantiation());
4457 // This variable may have local implicit instantiations that need to be
4458 // instantiated within this scope.
4459 PerformPendingInstantiations(/*LocalOnly=*/true);
4464 // Define any newly required vtables.
4465 DefineUsedVTables();
4467 // Instantiate any pending implicit instantiations found during the
4468 // instantiation of this template.
4469 PerformPendingInstantiations();
4471 // PendingInstantiations and VTableUses are restored through
4472 // SavePendingInstantiationsAndVTableUses's destructor.
4477 Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
4478 const CXXConstructorDecl *Tmpl,
4479 const MultiLevelTemplateArgumentList &TemplateArgs) {
4481 SmallVector<CXXCtorInitializer*, 4> NewInits;
4482 bool AnyErrors = Tmpl->isInvalidDecl();
4484 // Instantiate all the initializers.
4485 for (const auto *Init : Tmpl->inits()) {
4486 // Only instantiate written initializers, let Sema re-construct implicit
4488 if (!Init->isWritten())
4491 SourceLocation EllipsisLoc;
4493 if (Init->isPackExpansion()) {
4494 // This is a pack expansion. We should expand it now.
4495 TypeLoc BaseTL = Init->getTypeSourceInfo()->getTypeLoc();
4496 SmallVector<UnexpandedParameterPack, 4> Unexpanded;
4497 collectUnexpandedParameterPacks(BaseTL, Unexpanded);
4498 collectUnexpandedParameterPacks(Init->getInit(), Unexpanded);
4499 bool ShouldExpand = false;
4500 bool RetainExpansion = false;
4501 Optional<unsigned> NumExpansions;
4502 if (CheckParameterPacksForExpansion(Init->getEllipsisLoc(),
4503 BaseTL.getSourceRange(),
4505 TemplateArgs, ShouldExpand,
4509 New->setInvalidDecl();
4512 assert(ShouldExpand && "Partial instantiation of base initializer?");
4514 // Loop over all of the arguments in the argument pack(s),
4515 for (unsigned I = 0; I != *NumExpansions; ++I) {
4516 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, I);
4518 // Instantiate the initializer.
4519 ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs,
4520 /*CXXDirectInit=*/true);
4521 if (TempInit.isInvalid()) {
4526 // Instantiate the base type.
4527 TypeSourceInfo *BaseTInfo = SubstType(Init->getTypeSourceInfo(),
4529 Init->getSourceLocation(),
4530 New->getDeclName());
4536 // Build the initializer.
4537 MemInitResult NewInit = BuildBaseInitializer(BaseTInfo->getType(),
4538 BaseTInfo, TempInit.get(),
4541 if (NewInit.isInvalid()) {
4546 NewInits.push_back(NewInit.get());
4552 // Instantiate the initializer.
4553 ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs,
4554 /*CXXDirectInit=*/true);
4555 if (TempInit.isInvalid()) {
4560 MemInitResult NewInit;
4561 if (Init->isDelegatingInitializer() || Init->isBaseInitializer()) {
4562 TypeSourceInfo *TInfo = SubstType(Init->getTypeSourceInfo(),
4564 Init->getSourceLocation(),
4565 New->getDeclName());
4568 New->setInvalidDecl();
4572 if (Init->isBaseInitializer())
4573 NewInit = BuildBaseInitializer(TInfo->getType(), TInfo, TempInit.get(),
4574 New->getParent(), EllipsisLoc);
4576 NewInit = BuildDelegatingInitializer(TInfo, TempInit.get(),
4577 cast<CXXRecordDecl>(CurContext->getParent()));
4578 } else if (Init->isMemberInitializer()) {
4579 FieldDecl *Member = cast_or_null<FieldDecl>(FindInstantiatedDecl(
4580 Init->getMemberLocation(),
4585 New->setInvalidDecl();
4589 NewInit = BuildMemberInitializer(Member, TempInit.get(),
4590 Init->getSourceLocation());
4591 } else if (Init->isIndirectMemberInitializer()) {
4592 IndirectFieldDecl *IndirectMember =
4593 cast_or_null<IndirectFieldDecl>(FindInstantiatedDecl(
4594 Init->getMemberLocation(),
4595 Init->getIndirectMember(), TemplateArgs));
4597 if (!IndirectMember) {
4599 New->setInvalidDecl();
4603 NewInit = BuildMemberInitializer(IndirectMember, TempInit.get(),
4604 Init->getSourceLocation());
4607 if (NewInit.isInvalid()) {
4609 New->setInvalidDecl();
4611 NewInits.push_back(NewInit.get());
4615 // Assign all the initializers to the new constructor.
4616 ActOnMemInitializers(New,
4617 /*FIXME: ColonLoc */
4623 // TODO: this could be templated if the various decl types used the
4624 // same method name.
4625 static bool isInstantiationOf(ClassTemplateDecl *Pattern,
4626 ClassTemplateDecl *Instance) {
4627 Pattern = Pattern->getCanonicalDecl();
4630 Instance = Instance->getCanonicalDecl();
4631 if (Pattern == Instance) return true;
4632 Instance = Instance->getInstantiatedFromMemberTemplate();
4638 static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
4639 FunctionTemplateDecl *Instance) {
4640 Pattern = Pattern->getCanonicalDecl();
4643 Instance = Instance->getCanonicalDecl();
4644 if (Pattern == Instance) return true;
4645 Instance = Instance->getInstantiatedFromMemberTemplate();
4652 isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
4653 ClassTemplatePartialSpecializationDecl *Instance) {
4655 = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
4657 Instance = cast<ClassTemplatePartialSpecializationDecl>(
4658 Instance->getCanonicalDecl());
4659 if (Pattern == Instance)
4661 Instance = Instance->getInstantiatedFromMember();
4667 static bool isInstantiationOf(CXXRecordDecl *Pattern,
4668 CXXRecordDecl *Instance) {
4669 Pattern = Pattern->getCanonicalDecl();
4672 Instance = Instance->getCanonicalDecl();
4673 if (Pattern == Instance) return true;
4674 Instance = Instance->getInstantiatedFromMemberClass();
4680 static bool isInstantiationOf(FunctionDecl *Pattern,
4681 FunctionDecl *Instance) {
4682 Pattern = Pattern->getCanonicalDecl();
4685 Instance = Instance->getCanonicalDecl();
4686 if (Pattern == Instance) return true;
4687 Instance = Instance->getInstantiatedFromMemberFunction();
4693 static bool isInstantiationOf(EnumDecl *Pattern,
4694 EnumDecl *Instance) {
4695 Pattern = Pattern->getCanonicalDecl();
4698 Instance = Instance->getCanonicalDecl();
4699 if (Pattern == Instance) return true;
4700 Instance = Instance->getInstantiatedFromMemberEnum();
4706 static bool isInstantiationOf(UsingShadowDecl *Pattern,
4707 UsingShadowDecl *Instance,
4709 return declaresSameEntity(C.getInstantiatedFromUsingShadowDecl(Instance),
4713 static bool isInstantiationOf(UsingDecl *Pattern, UsingDecl *Instance,
4715 return declaresSameEntity(C.getInstantiatedFromUsingDecl(Instance), Pattern);
4718 template<typename T>
4719 static bool isInstantiationOfUnresolvedUsingDecl(T *Pattern, Decl *Other,
4721 // An unresolved using declaration can instantiate to an unresolved using
4722 // declaration, or to a using declaration or a using declaration pack.
4724 // Multiple declarations can claim to be instantiated from an unresolved
4725 // using declaration if it's a pack expansion. We want the UsingPackDecl
4726 // in that case, not the individual UsingDecls within the pack.
4727 bool OtherIsPackExpansion;
4728 NamedDecl *OtherFrom;
4729 if (auto *OtherUUD = dyn_cast<T>(Other)) {
4730 OtherIsPackExpansion = OtherUUD->isPackExpansion();
4731 OtherFrom = Ctx.getInstantiatedFromUsingDecl(OtherUUD);
4732 } else if (auto *OtherUPD = dyn_cast<UsingPackDecl>(Other)) {
4733 OtherIsPackExpansion = true;
4734 OtherFrom = OtherUPD->getInstantiatedFromUsingDecl();
4735 } else if (auto *OtherUD = dyn_cast<UsingDecl>(Other)) {
4736 OtherIsPackExpansion = false;
4737 OtherFrom = Ctx.getInstantiatedFromUsingDecl(OtherUD);
4741 return Pattern->isPackExpansion() == OtherIsPackExpansion &&
4742 declaresSameEntity(OtherFrom, Pattern);
4745 static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
4746 VarDecl *Instance) {
4747 assert(Instance->isStaticDataMember());
4749 Pattern = Pattern->getCanonicalDecl();
4752 Instance = Instance->getCanonicalDecl();
4753 if (Pattern == Instance) return true;
4754 Instance = Instance->getInstantiatedFromStaticDataMember();
4760 // Other is the prospective instantiation
4761 // D is the prospective pattern
4762 static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
4763 if (auto *UUD = dyn_cast<UnresolvedUsingTypenameDecl>(D))
4764 return isInstantiationOfUnresolvedUsingDecl(UUD, Other, Ctx);
4766 if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(D))
4767 return isInstantiationOfUnresolvedUsingDecl(UUD, Other, Ctx);
4769 if (D->getKind() != Other->getKind())
4772 if (auto *Record = dyn_cast<CXXRecordDecl>(Other))
4773 return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
4775 if (auto *Function = dyn_cast<FunctionDecl>(Other))
4776 return isInstantiationOf(cast<FunctionDecl>(D), Function);
4778 if (auto *Enum = dyn_cast<EnumDecl>(Other))
4779 return isInstantiationOf(cast<EnumDecl>(D), Enum);
4781 if (auto *Var = dyn_cast<VarDecl>(Other))
4782 if (Var->isStaticDataMember())
4783 return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
4785 if (auto *Temp = dyn_cast<ClassTemplateDecl>(Other))
4786 return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
4788 if (auto *Temp = dyn_cast<FunctionTemplateDecl>(Other))
4789 return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
4791 if (auto *PartialSpec =
4792 dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
4793 return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
4796 if (auto *Field = dyn_cast<FieldDecl>(Other)) {
4797 if (!Field->getDeclName()) {
4798 // This is an unnamed field.
4799 return declaresSameEntity(Ctx.getInstantiatedFromUnnamedFieldDecl(Field),
4800 cast<FieldDecl>(D));
4804 if (auto *Using = dyn_cast<UsingDecl>(Other))
4805 return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
4807 if (auto *Shadow = dyn_cast<UsingShadowDecl>(Other))
4808 return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
4810 return D->getDeclName() &&
4811 D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
4814 template<typename ForwardIterator>
4815 static NamedDecl *findInstantiationOf(ASTContext &Ctx,
4817 ForwardIterator first,
4818 ForwardIterator last) {
4819 for (; first != last; ++first)
4820 if (isInstantiationOf(Ctx, D, *first))
4821 return cast<NamedDecl>(*first);
4826 /// \brief Finds the instantiation of the given declaration context
4827 /// within the current instantiation.
4829 /// \returns NULL if there was an error
4830 DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
4831 const MultiLevelTemplateArgumentList &TemplateArgs) {
4832 if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
4833 Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
4834 return cast_or_null<DeclContext>(ID);
4838 /// \brief Find the instantiation of the given declaration within the
4839 /// current instantiation.
4841 /// This routine is intended to be used when \p D is a declaration
4842 /// referenced from within a template, that needs to mapped into the
4843 /// corresponding declaration within an instantiation. For example,
4847 /// template<typename T>
4850 /// KnownValue = sizeof(T)
4853 /// bool getKind() const { return KnownValue; }
4856 /// template struct X<int>;
4859 /// In the instantiation of <tt>X<int>::getKind()</tt>, we need to map the
4860 /// \p EnumConstantDecl for \p KnownValue (which refers to
4861 /// <tt>X<T>::<Kind>::KnownValue</tt>) to its instantiation
4862 /// (<tt>X<int>::<Kind>::KnownValue</tt>). \p FindInstantiatedDecl performs
4863 /// this mapping from within the instantiation of <tt>X<int></tt>.
4864 NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
4865 const MultiLevelTemplateArgumentList &TemplateArgs) {
4866 DeclContext *ParentDC = D->getDeclContext();
4867 // FIXME: Parmeters of pointer to functions (y below) that are themselves
4868 // parameters (p below) can have their ParentDC set to the translation-unit
4869 // - thus we can not consistently check if the ParentDC of such a parameter
4870 // is Dependent or/and a FunctionOrMethod.
4871 // For e.g. this code, during Template argument deduction tries to
4872 // find an instantiated decl for (T y) when the ParentDC for y is
4873 // the translation unit.
4874 // e.g. template <class T> void Foo(auto (*p)(T y) -> decltype(y())) {}
4875 // float baz(float(*)()) { return 0.0; }
4877 // The better fix here is perhaps to ensure that a ParmVarDecl, by the time
4878 // it gets here, always has a FunctionOrMethod as its ParentDC??
4880 // - as long as we have a ParmVarDecl whose parent is non-dependent and
4881 // whose type is not instantiation dependent, do nothing to the decl
4882 // - otherwise find its instantiated decl.
4883 if (isa<ParmVarDecl>(D) && !ParentDC->isDependentContext() &&
4884 !cast<ParmVarDecl>(D)->getType()->isInstantiationDependentType())
4886 if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
4887 isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
4888 (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext()) ||
4889 (isa<CXXRecordDecl>(D) && cast<CXXRecordDecl>(D)->isLambda())) {
4890 // D is a local of some kind. Look into the map of local
4891 // declarations to their instantiations.
4892 if (CurrentInstantiationScope) {
4893 if (auto Found = CurrentInstantiationScope->findInstantiationOf(D)) {
4894 if (Decl *FD = Found->dyn_cast<Decl *>())
4895 return cast<NamedDecl>(FD);
4897 int PackIdx = ArgumentPackSubstitutionIndex;
4898 assert(PackIdx != -1 &&
4899 "found declaration pack but not pack expanding");
4900 typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack;
4901 return cast<NamedDecl>((*Found->get<DeclArgumentPack *>())[PackIdx]);
4905 // If we're performing a partial substitution during template argument
4906 // deduction, we may not have values for template parameters yet. They
4907 // just map to themselves.
4908 if (isa<NonTypeTemplateParmDecl>(D) || isa<TemplateTypeParmDecl>(D) ||
4909 isa<TemplateTemplateParmDecl>(D))
4912 if (D->isInvalidDecl())
4915 // Normally this function only searches for already instantiated declaration
4916 // however we have to make an exclusion for local types used before
4917 // definition as in the code:
4919 // template<typename T> void f1() {
4920 // void g1(struct x1);
4924 // In this case instantiation of the type of 'g1' requires definition of
4925 // 'x1', which is defined later. Error recovery may produce an enum used
4926 // before definition. In these cases we need to instantiate relevant
4927 // declarations here.
4928 bool NeedInstantiate = false;
4929 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D))
4930 NeedInstantiate = RD->isLocalClass();
4932 NeedInstantiate = isa<EnumDecl>(D);
4933 if (NeedInstantiate) {
4934 Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
4935 CurrentInstantiationScope->InstantiatedLocal(D, Inst);
4936 return cast<TypeDecl>(Inst);
4939 // If we didn't find the decl, then we must have a label decl that hasn't
4940 // been found yet. Lazily instantiate it and return it now.
4941 assert(isa<LabelDecl>(D));
4943 Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
4944 assert(Inst && "Failed to instantiate label??");
4946 CurrentInstantiationScope->InstantiatedLocal(D, Inst);
4947 return cast<LabelDecl>(Inst);
4950 // For variable template specializations, update those that are still
4952 if (VarTemplateSpecializationDecl *VarSpec =
4953 dyn_cast<VarTemplateSpecializationDecl>(D)) {
4954 bool InstantiationDependent = false;
4955 const TemplateArgumentListInfo &VarTemplateArgs =
4956 VarSpec->getTemplateArgsInfo();
4957 if (TemplateSpecializationType::anyDependentTemplateArguments(
4958 VarTemplateArgs, InstantiationDependent))
4959 D = cast<NamedDecl>(
4960 SubstDecl(D, VarSpec->getDeclContext(), TemplateArgs));
4964 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
4965 if (!Record->isDependentContext())
4968 // Determine whether this record is the "templated" declaration describing
4969 // a class template or class template partial specialization.
4970 ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
4972 ClassTemplate = ClassTemplate->getCanonicalDecl();
4973 else if (ClassTemplatePartialSpecializationDecl *PartialSpec
4974 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record))
4975 ClassTemplate = PartialSpec->getSpecializedTemplate()->getCanonicalDecl();
4977 // Walk the current context to find either the record or an instantiation of
4979 DeclContext *DC = CurContext;
4980 while (!DC->isFileContext()) {
4981 // If we're performing substitution while we're inside the template
4982 // definition, we'll find our own context. We're done.
4983 if (DC->Equals(Record))
4986 if (CXXRecordDecl *InstRecord = dyn_cast<CXXRecordDecl>(DC)) {
4987 // Check whether we're in the process of instantiating a class template
4988 // specialization of the template we're mapping.
4989 if (ClassTemplateSpecializationDecl *InstSpec
4990 = dyn_cast<ClassTemplateSpecializationDecl>(InstRecord)){
4991 ClassTemplateDecl *SpecTemplate = InstSpec->getSpecializedTemplate();
4992 if (ClassTemplate && isInstantiationOf(ClassTemplate, SpecTemplate))
4996 // Check whether we're in the process of instantiating a member class.
4997 if (isInstantiationOf(Record, InstRecord))
5001 // Move to the outer template scope.
5002 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) {
5003 if (FD->getFriendObjectKind() && FD->getDeclContext()->isFileContext()){
5004 DC = FD->getLexicalDeclContext();
5007 // An implicit deduction guide acts as if it's within the class template
5008 // specialization described by its name and first N template params.
5009 auto *Guide = dyn_cast<CXXDeductionGuideDecl>(FD);
5010 if (Guide && Guide->isImplicit()) {
5011 TemplateDecl *TD = Guide->getDeducedTemplate();
5012 // Convert the arguments to an "as-written" list.
5013 TemplateArgumentListInfo Args(Loc, Loc);
5014 for (TemplateArgument Arg : TemplateArgs.getInnermost().take_front(
5015 TD->getTemplateParameters()->size())) {
5016 ArrayRef<TemplateArgument> Unpacked(Arg);
5017 if (Arg.getKind() == TemplateArgument::Pack)
5018 Unpacked = Arg.pack_elements();
5019 for (TemplateArgument UnpackedArg : Unpacked)
5021 getTrivialTemplateArgumentLoc(UnpackedArg, QualType(), Loc));
5023 QualType T = CheckTemplateIdType(TemplateName(TD), Loc, Args);
5026 DC = T->getAsCXXRecordDecl();
5031 DC = DC->getParent();
5034 // Fall through to deal with other dependent record types (e.g.,
5035 // anonymous unions in class templates).
5038 if (!ParentDC->isDependentContext())
5041 ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
5045 if (ParentDC != D->getDeclContext()) {
5046 // We performed some kind of instantiation in the parent context,
5047 // so now we need to look into the instantiated parent context to
5048 // find the instantiation of the declaration D.
5050 // If our context used to be dependent, we may need to instantiate
5051 // it before performing lookup into that context.
5052 bool IsBeingInstantiated = false;
5053 if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
5054 if (!Spec->isDependentContext()) {
5055 QualType T = Context.getTypeDeclType(Spec);
5056 const RecordType *Tag = T->getAs<RecordType>();
5057 assert(Tag && "type of non-dependent record is not a RecordType");
5058 if (Tag->isBeingDefined())
5059 IsBeingInstantiated = true;
5060 if (!Tag->isBeingDefined() &&
5061 RequireCompleteType(Loc, T, diag::err_incomplete_type))
5064 ParentDC = Tag->getDecl();
5068 NamedDecl *Result = nullptr;
5069 // FIXME: If the name is a dependent name, this lookup won't necessarily
5070 // find it. Does that ever matter?
5071 if (auto Name = D->getDeclName()) {
5072 DeclarationNameInfo NameInfo(Name, D->getLocation());
5073 Name = SubstDeclarationNameInfo(NameInfo, TemplateArgs).getName();
5076 DeclContext::lookup_result Found = ParentDC->lookup(Name);
5077 Result = findInstantiationOf(Context, D, Found.begin(), Found.end());
5079 // Since we don't have a name for the entity we're looking for,
5080 // our only option is to walk through all of the declarations to
5081 // find that name. This will occur in a few cases:
5083 // - anonymous struct/union within a template
5084 // - unnamed class/struct/union/enum within a template
5086 // FIXME: Find a better way to find these instantiations!
5087 Result = findInstantiationOf(Context, D,
5088 ParentDC->decls_begin(),
5089 ParentDC->decls_end());
5093 if (isa<UsingShadowDecl>(D)) {
5094 // UsingShadowDecls can instantiate to nothing because of using hiding.
5095 } else if (Diags.hasErrorOccurred()) {
5096 // We've already complained about something, so most likely this
5097 // declaration failed to instantiate. There's no point in complaining
5098 // further, since this is normal in invalid code.
5099 } else if (IsBeingInstantiated) {
5100 // The class in which this member exists is currently being
5101 // instantiated, and we haven't gotten around to instantiating this
5102 // member yet. This can happen when the code uses forward declarations
5103 // of member classes, and introduces ordering dependencies via
5104 // template instantiation.
5105 Diag(Loc, diag::err_member_not_yet_instantiated)
5107 << Context.getTypeDeclType(cast<CXXRecordDecl>(ParentDC));
5108 Diag(D->getLocation(), diag::note_non_instantiated_member_here);
5109 } else if (EnumConstantDecl *ED = dyn_cast<EnumConstantDecl>(D)) {
5110 // This enumeration constant was found when the template was defined,
5111 // but can't be found in the instantiation. This can happen if an
5112 // unscoped enumeration member is explicitly specialized.
5113 EnumDecl *Enum = cast<EnumDecl>(ED->getLexicalDeclContext());
5114 EnumDecl *Spec = cast<EnumDecl>(FindInstantiatedDecl(Loc, Enum,
5116 assert(Spec->getTemplateSpecializationKind() ==
5117 TSK_ExplicitSpecialization);
5118 Diag(Loc, diag::err_enumerator_does_not_exist)
5120 << Context.getTypeDeclType(cast<TypeDecl>(Spec->getDeclContext()));
5121 Diag(Spec->getLocation(), diag::note_enum_specialized_here)
5122 << Context.getTypeDeclType(Spec);
5124 // We should have found something, but didn't.
5125 llvm_unreachable("Unable to find instantiation of declaration!");
5135 /// \brief Performs template instantiation for all implicit template
5136 /// instantiations we have seen until this point.
5137 void Sema::PerformPendingInstantiations(bool LocalOnly) {
5138 while (!PendingLocalImplicitInstantiations.empty() ||
5139 (!LocalOnly && !PendingInstantiations.empty())) {
5140 PendingImplicitInstantiation Inst;
5142 if (PendingLocalImplicitInstantiations.empty()) {
5143 Inst = PendingInstantiations.front();
5144 PendingInstantiations.pop_front();
5146 Inst = PendingLocalImplicitInstantiations.front();
5147 PendingLocalImplicitInstantiations.pop_front();
5150 // Instantiate function definitions
5151 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
5152 bool DefinitionRequired = Function->getTemplateSpecializationKind() ==
5153 TSK_ExplicitInstantiationDefinition;
5154 InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true,
5155 DefinitionRequired, true);
5159 // Instantiate variable definitions
5160 VarDecl *Var = cast<VarDecl>(Inst.first);
5162 assert((Var->isStaticDataMember() ||
5163 isa<VarTemplateSpecializationDecl>(Var)) &&
5164 "Not a static data member, nor a variable template"
5165 " specialization?");
5167 // Don't try to instantiate declarations if the most recent redeclaration
5169 if (Var->getMostRecentDecl()->isInvalidDecl())
5172 // Check if the most recent declaration has changed the specialization kind
5173 // and removed the need for implicit instantiation.
5174 switch (Var->getMostRecentDecl()->getTemplateSpecializationKind()) {
5175 case TSK_Undeclared:
5176 llvm_unreachable("Cannot instantitiate an undeclared specialization.");
5177 case TSK_ExplicitInstantiationDeclaration:
5178 case TSK_ExplicitSpecialization:
5179 continue; // No longer need to instantiate this type.
5180 case TSK_ExplicitInstantiationDefinition:
5181 // We only need an instantiation if the pending instantiation *is* the
5182 // explicit instantiation.
5183 if (Var != Var->getMostRecentDecl()) continue;
5184 case TSK_ImplicitInstantiation:
5188 PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
5189 "instantiating variable definition");
5190 bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
5191 TSK_ExplicitInstantiationDefinition;
5193 // Instantiate static data member definitions or variable template
5195 InstantiateVariableDefinition(/*FIXME:*/ Inst.second, Var, true,
5196 DefinitionRequired, true);
5200 void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
5201 const MultiLevelTemplateArgumentList &TemplateArgs) {
5202 for (auto DD : Pattern->ddiags()) {
5203 switch (DD->getKind()) {
5204 case DependentDiagnostic::Access:
5205 HandleDependentAccessCheck(*DD, TemplateArgs);