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 NewBD->setReferenced(D->isReferenced());
681 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewBD);
685 Decl *TemplateDeclInstantiator::VisitDecompositionDecl(DecompositionDecl *D) {
686 // Transform the bindings first.
687 SmallVector<BindingDecl*, 16> NewBindings;
688 for (auto *OldBD : D->bindings())
689 NewBindings.push_back(cast<BindingDecl>(VisitBindingDecl(OldBD)));
690 ArrayRef<BindingDecl*> NewBindingArray = NewBindings;
692 auto *NewDD = cast_or_null<DecompositionDecl>(
693 VisitVarDecl(D, /*InstantiatingVarTemplate=*/false, &NewBindingArray));
695 if (!NewDD || NewDD->isInvalidDecl())
696 for (auto *NewBD : NewBindings)
697 NewBD->setInvalidDecl();
702 Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
703 return VisitVarDecl(D, /*InstantiatingVarTemplate=*/false);
706 Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D,
707 bool InstantiatingVarTemplate,
708 ArrayRef<BindingDecl*> *Bindings) {
710 // Do substitution on the type of the declaration
711 TypeSourceInfo *DI = SemaRef.SubstType(
712 D->getTypeSourceInfo(), TemplateArgs, D->getTypeSpecStartLoc(),
713 D->getDeclName(), /*AllowDeducedTST*/true);
717 if (DI->getType()->isFunctionType()) {
718 SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
719 << D->isStaticDataMember() << DI->getType();
723 DeclContext *DC = Owner;
724 if (D->isLocalExternDecl())
725 SemaRef.adjustContextForLocalExternDecl(DC);
727 // Build the instantiated declaration.
730 Var = DecompositionDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
731 D->getLocation(), DI->getType(), DI,
732 D->getStorageClass(), *Bindings);
734 Var = VarDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
735 D->getLocation(), D->getIdentifier(), DI->getType(),
736 DI, D->getStorageClass());
738 // In ARC, infer 'retaining' for variables of retainable type.
739 if (SemaRef.getLangOpts().ObjCAutoRefCount &&
740 SemaRef.inferObjCARCLifetime(Var))
741 Var->setInvalidDecl();
743 // Substitute the nested name specifier, if any.
744 if (SubstQualifier(D, Var))
747 SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs, Owner,
748 StartingScope, InstantiatingVarTemplate);
750 if (D->isNRVOVariable()) {
751 QualType ReturnType = cast<FunctionDecl>(DC)->getReturnType();
752 if (SemaRef.isCopyElisionCandidate(ReturnType, Var, false))
753 Var->setNRVOVariable(true);
756 Var->setImplicit(D->isImplicit());
761 Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
763 = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
764 D->getAccessSpecifierLoc(), D->getColonLoc());
765 Owner->addHiddenDecl(AD);
769 Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
770 bool Invalid = false;
771 TypeSourceInfo *DI = D->getTypeSourceInfo();
772 if (DI->getType()->isInstantiationDependentType() ||
773 DI->getType()->isVariablyModifiedType()) {
774 DI = SemaRef.SubstType(DI, TemplateArgs,
775 D->getLocation(), D->getDeclName());
777 DI = D->getTypeSourceInfo();
779 } else if (DI->getType()->isFunctionType()) {
780 // C++ [temp.arg.type]p3:
781 // If a declaration acquires a function type through a type
782 // dependent on a template-parameter and this causes a
783 // declaration that does not use the syntactic form of a
784 // function declarator to have function type, the program is
786 SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
791 SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
794 Expr *BitWidth = D->getBitWidth();
798 // The bit-width expression is a constant expression.
799 EnterExpressionEvaluationContext Unevaluated(
800 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
802 ExprResult InstantiatedBitWidth
803 = SemaRef.SubstExpr(BitWidth, TemplateArgs);
804 if (InstantiatedBitWidth.isInvalid()) {
808 BitWidth = InstantiatedBitWidth.getAs<Expr>();
811 FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
813 cast<RecordDecl>(Owner),
817 D->getInClassInitStyle(),
818 D->getInnerLocStart(),
822 cast<Decl>(Owner)->setInvalidDecl();
826 SemaRef.InstantiateAttrs(TemplateArgs, D, Field, LateAttrs, StartingScope);
828 if (Field->hasAttrs())
829 SemaRef.CheckAlignasUnderalignment(Field);
832 Field->setInvalidDecl();
834 if (!Field->getDeclName()) {
835 // Keep track of where this decl came from.
836 SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
838 if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
839 if (Parent->isAnonymousStructOrUnion() &&
840 Parent->getRedeclContext()->isFunctionOrMethod())
841 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
844 Field->setImplicit(D->isImplicit());
845 Field->setAccess(D->getAccess());
846 Owner->addDecl(Field);
851 Decl *TemplateDeclInstantiator::VisitMSPropertyDecl(MSPropertyDecl *D) {
852 bool Invalid = false;
853 TypeSourceInfo *DI = D->getTypeSourceInfo();
855 if (DI->getType()->isVariablyModifiedType()) {
856 SemaRef.Diag(D->getLocation(), diag::err_property_is_variably_modified)
859 } else if (DI->getType()->isInstantiationDependentType()) {
860 DI = SemaRef.SubstType(DI, TemplateArgs,
861 D->getLocation(), D->getDeclName());
863 DI = D->getTypeSourceInfo();
865 } else if (DI->getType()->isFunctionType()) {
866 // C++ [temp.arg.type]p3:
867 // If a declaration acquires a function type through a type
868 // dependent on a template-parameter and this causes a
869 // declaration that does not use the syntactic form of a
870 // function declarator to have function type, the program is
872 SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
877 SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
880 MSPropertyDecl *Property = MSPropertyDecl::Create(
881 SemaRef.Context, Owner, D->getLocation(), D->getDeclName(), DI->getType(),
882 DI, D->getLocStart(), D->getGetterId(), D->getSetterId());
884 SemaRef.InstantiateAttrs(TemplateArgs, D, Property, LateAttrs,
888 Property->setInvalidDecl();
890 Property->setAccess(D->getAccess());
891 Owner->addDecl(Property);
896 Decl *TemplateDeclInstantiator::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
897 NamedDecl **NamedChain =
898 new (SemaRef.Context)NamedDecl*[D->getChainingSize()];
901 for (auto *PI : D->chain()) {
902 NamedDecl *Next = SemaRef.FindInstantiatedDecl(D->getLocation(), PI,
907 NamedChain[i++] = Next;
910 QualType T = cast<FieldDecl>(NamedChain[i-1])->getType();
911 IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
912 SemaRef.Context, Owner, D->getLocation(), D->getIdentifier(), T,
913 {NamedChain, D->getChainingSize()});
915 for (const auto *Attr : D->attrs())
916 IndirectField->addAttr(Attr->clone(SemaRef.Context));
918 IndirectField->setImplicit(D->isImplicit());
919 IndirectField->setAccess(D->getAccess());
920 Owner->addDecl(IndirectField);
921 return IndirectField;
924 Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
925 // Handle friend type expressions by simply substituting template
926 // parameters into the pattern type and checking the result.
927 if (TypeSourceInfo *Ty = D->getFriendType()) {
928 TypeSourceInfo *InstTy;
929 // If this is an unsupported friend, don't bother substituting template
930 // arguments into it. The actual type referred to won't be used by any
931 // parts of Clang, and may not be valid for instantiating. Just use the
932 // same info for the instantiated friend.
933 if (D->isUnsupportedFriend()) {
936 InstTy = SemaRef.SubstType(Ty, TemplateArgs,
937 D->getLocation(), DeclarationName());
942 FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getLocStart(),
943 D->getFriendLoc(), InstTy);
947 FD->setAccess(AS_public);
948 FD->setUnsupportedFriend(D->isUnsupportedFriend());
953 NamedDecl *ND = D->getFriendDecl();
954 assert(ND && "friend decl must be a decl or a type!");
956 // All of the Visit implementations for the various potential friend
957 // declarations have to be carefully written to work for friend
958 // objects, with the most important detail being that the target
959 // decl should almost certainly not be placed in Owner.
960 Decl *NewND = Visit(ND);
961 if (!NewND) return nullptr;
964 FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
965 cast<NamedDecl>(NewND), D->getFriendLoc());
966 FD->setAccess(AS_public);
967 FD->setUnsupportedFriend(D->isUnsupportedFriend());
972 Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
973 Expr *AssertExpr = D->getAssertExpr();
975 // The expression in a static assertion is a constant expression.
976 EnterExpressionEvaluationContext Unevaluated(
977 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
979 ExprResult InstantiatedAssertExpr
980 = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
981 if (InstantiatedAssertExpr.isInvalid())
984 return SemaRef.BuildStaticAssertDeclaration(D->getLocation(),
985 InstantiatedAssertExpr.get(),
991 Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
992 EnumDecl *PrevDecl = nullptr;
993 if (EnumDecl *PatternPrev = getPreviousDeclForInstantiation(D)) {
994 NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
997 if (!Prev) return nullptr;
998 PrevDecl = cast<EnumDecl>(Prev);
1001 EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
1002 D->getLocation(), D->getIdentifier(),
1003 PrevDecl, D->isScoped(),
1004 D->isScopedUsingClassTag(), D->isFixed());
1006 if (TypeSourceInfo *TI = D->getIntegerTypeSourceInfo()) {
1007 // If we have type source information for the underlying type, it means it
1008 // has been explicitly set by the user. Perform substitution on it before
1010 SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
1011 TypeSourceInfo *NewTI = SemaRef.SubstType(TI, TemplateArgs, UnderlyingLoc,
1013 if (!NewTI || SemaRef.CheckEnumUnderlyingType(NewTI))
1014 Enum->setIntegerType(SemaRef.Context.IntTy);
1016 Enum->setIntegerTypeSourceInfo(NewTI);
1018 assert(!D->getIntegerType()->isDependentType()
1019 && "Dependent type without type source info");
1020 Enum->setIntegerType(D->getIntegerType());
1024 SemaRef.InstantiateAttrs(TemplateArgs, D, Enum);
1026 Enum->setInstantiationOfMemberEnum(D, TSK_ImplicitInstantiation);
1027 Enum->setAccess(D->getAccess());
1028 // Forward the mangling number from the template to the instantiated decl.
1029 SemaRef.Context.setManglingNumber(Enum, SemaRef.Context.getManglingNumber(D));
1030 // See if the old tag was defined along with a declarator.
1031 // If it did, mark the new tag as being associated with that declarator.
1032 if (DeclaratorDecl *DD = SemaRef.Context.getDeclaratorForUnnamedTagDecl(D))
1033 SemaRef.Context.addDeclaratorForUnnamedTagDecl(Enum, DD);
1034 // See if the old tag was defined along with a typedef.
1035 // If it did, mark the new tag as being associated with that typedef.
1036 if (TypedefNameDecl *TND = SemaRef.Context.getTypedefNameForUnnamedTagDecl(D))
1037 SemaRef.Context.addTypedefNameForUnnamedTagDecl(Enum, TND);
1038 if (SubstQualifier(D, Enum)) return nullptr;
1039 Owner->addDecl(Enum);
1041 EnumDecl *Def = D->getDefinition();
1042 if (Def && Def != D) {
1043 // If this is an out-of-line definition of an enum member template, check
1044 // that the underlying types match in the instantiation of both
1046 if (TypeSourceInfo *TI = Def->getIntegerTypeSourceInfo()) {
1047 SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
1048 QualType DefnUnderlying =
1049 SemaRef.SubstType(TI->getType(), TemplateArgs,
1050 UnderlyingLoc, DeclarationName());
1051 SemaRef.CheckEnumRedeclaration(Def->getLocation(), Def->isScoped(),
1053 /*EnumUnderlyingIsImplicit=*/false, Enum);
1057 // C++11 [temp.inst]p1: The implicit instantiation of a class template
1058 // specialization causes the implicit instantiation of the declarations, but
1059 // not the definitions of scoped member enumerations.
1061 // DR1484 clarifies that enumeration definitions inside of a template
1062 // declaration aren't considered entities that can be separately instantiated
1063 // from the rest of the entity they are declared inside of.
1064 if (isDeclWithinFunction(D) ? D == Def : Def && !Enum->isScoped()) {
1065 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
1066 InstantiateEnumDefinition(Enum, Def);
1072 void TemplateDeclInstantiator::InstantiateEnumDefinition(
1073 EnumDecl *Enum, EnumDecl *Pattern) {
1074 Enum->startDefinition();
1076 // Update the location to refer to the definition.
1077 Enum->setLocation(Pattern->getLocation());
1079 SmallVector<Decl*, 4> Enumerators;
1081 EnumConstantDecl *LastEnumConst = nullptr;
1082 for (auto *EC : Pattern->enumerators()) {
1083 // The specified value for the enumerator.
1084 ExprResult Value((Expr *)nullptr);
1085 if (Expr *UninstValue = EC->getInitExpr()) {
1086 // The enumerator's value expression is a constant expression.
1087 EnterExpressionEvaluationContext Unevaluated(
1088 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
1090 Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
1093 // Drop the initial value and continue.
1094 bool isInvalid = false;
1095 if (Value.isInvalid()) {
1100 EnumConstantDecl *EnumConst
1101 = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
1102 EC->getLocation(), EC->getIdentifier(),
1107 EnumConst->setInvalidDecl();
1108 Enum->setInvalidDecl();
1112 SemaRef.InstantiateAttrs(TemplateArgs, EC, EnumConst);
1114 EnumConst->setAccess(Enum->getAccess());
1115 Enum->addDecl(EnumConst);
1116 Enumerators.push_back(EnumConst);
1117 LastEnumConst = EnumConst;
1119 if (Pattern->getDeclContext()->isFunctionOrMethod() &&
1120 !Enum->isScoped()) {
1121 // If the enumeration is within a function or method, record the enum
1122 // constant as a local.
1123 SemaRef.CurrentInstantiationScope->InstantiatedLocal(EC, EnumConst);
1128 SemaRef.ActOnEnumBody(Enum->getLocation(), Enum->getBraceRange(), Enum,
1133 Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
1134 llvm_unreachable("EnumConstantDecls can only occur within EnumDecls.");
1138 TemplateDeclInstantiator::VisitBuiltinTemplateDecl(BuiltinTemplateDecl *D) {
1139 llvm_unreachable("BuiltinTemplateDecls cannot be instantiated.");
1142 Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1143 bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1145 // Create a local instantiation scope for this class template, which
1146 // will contain the instantiations of the template parameters.
1147 LocalInstantiationScope Scope(SemaRef);
1148 TemplateParameterList *TempParams = D->getTemplateParameters();
1149 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1153 CXXRecordDecl *Pattern = D->getTemplatedDecl();
1155 // Instantiate the qualifier. We have to do this first in case
1156 // we're a friend declaration, because if we are then we need to put
1157 // the new declaration in the appropriate context.
1158 NestedNameSpecifierLoc QualifierLoc = Pattern->getQualifierLoc();
1160 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1166 CXXRecordDecl *PrevDecl = nullptr;
1167 ClassTemplateDecl *PrevClassTemplate = nullptr;
1169 if (!isFriend && getPreviousDeclForInstantiation(Pattern)) {
1170 DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
1171 if (!Found.empty()) {
1172 PrevClassTemplate = dyn_cast<ClassTemplateDecl>(Found.front());
1173 if (PrevClassTemplate)
1174 PrevDecl = PrevClassTemplate->getTemplatedDecl();
1178 // If this isn't a friend, then it's a member template, in which
1179 // case we just want to build the instantiation in the
1180 // specialization. If it is a friend, we want to build it in
1181 // the appropriate context.
1182 DeclContext *DC = Owner;
1186 SS.Adopt(QualifierLoc);
1187 DC = SemaRef.computeDeclContext(SS);
1188 if (!DC) return nullptr;
1190 DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
1191 Pattern->getDeclContext(),
1195 // Look for a previous declaration of the template in the owning
1197 LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
1198 Sema::LookupOrdinaryName,
1199 SemaRef.forRedeclarationInCurContext());
1200 SemaRef.LookupQualifiedName(R, DC);
1202 if (R.isSingleResult()) {
1203 PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
1204 if (PrevClassTemplate)
1205 PrevDecl = PrevClassTemplate->getTemplatedDecl();
1208 if (!PrevClassTemplate && QualifierLoc) {
1209 SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
1210 << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
1211 << QualifierLoc.getSourceRange();
1215 bool AdoptedPreviousTemplateParams = false;
1216 if (PrevClassTemplate) {
1217 bool Complain = true;
1219 // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
1220 // template for struct std::tr1::__detail::_Map_base, where the
1221 // template parameters of the friend declaration don't match the
1222 // template parameters of the original declaration. In this one
1223 // case, we don't complain about the ill-formed friend
1225 if (isFriend && Pattern->getIdentifier() &&
1226 Pattern->getIdentifier()->isStr("_Map_base") &&
1227 DC->isNamespace() &&
1228 cast<NamespaceDecl>(DC)->getIdentifier() &&
1229 cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
1230 DeclContext *DCParent = DC->getParent();
1231 if (DCParent->isNamespace() &&
1232 cast<NamespaceDecl>(DCParent)->getIdentifier() &&
1233 cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
1234 if (cast<Decl>(DCParent)->isInStdNamespace())
1239 TemplateParameterList *PrevParams
1240 = PrevClassTemplate->getTemplateParameters();
1242 // Make sure the parameter lists match.
1243 if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
1245 Sema::TPL_TemplateMatch)) {
1249 AdoptedPreviousTemplateParams = true;
1250 InstParams = PrevParams;
1253 // Do some additional validation, then merge default arguments
1254 // from the existing declarations.
1255 if (!AdoptedPreviousTemplateParams &&
1256 SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
1257 Sema::TPC_ClassTemplate))
1262 CXXRecordDecl *RecordInst
1263 = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
1264 Pattern->getLocStart(), Pattern->getLocation(),
1265 Pattern->getIdentifier(), PrevDecl,
1266 /*DelayTypeCreation=*/true);
1269 RecordInst->setQualifierInfo(QualifierLoc);
1271 ClassTemplateDecl *Inst
1272 = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
1273 D->getIdentifier(), InstParams, RecordInst);
1274 assert(!(isFriend && Owner->isDependentContext()));
1275 Inst->setPreviousDecl(PrevClassTemplate);
1277 RecordInst->setDescribedClassTemplate(Inst);
1280 if (PrevClassTemplate)
1281 Inst->setAccess(PrevClassTemplate->getAccess());
1283 Inst->setAccess(D->getAccess());
1285 Inst->setObjectOfFriendDecl();
1286 // TODO: do we want to track the instantiation progeny of this
1287 // friend target decl?
1289 Inst->setAccess(D->getAccess());
1290 if (!PrevClassTemplate)
1291 Inst->setInstantiatedFromMemberTemplate(D);
1294 // Trigger creation of the type for the instantiation.
1295 SemaRef.Context.getInjectedClassNameType(RecordInst,
1296 Inst->getInjectedClassNameSpecialization());
1298 // Finish handling of friends.
1300 DC->makeDeclVisibleInContext(Inst);
1301 Inst->setLexicalDeclContext(Owner);
1302 RecordInst->setLexicalDeclContext(Owner);
1306 if (D->isOutOfLine()) {
1307 Inst->setLexicalDeclContext(D->getLexicalDeclContext());
1308 RecordInst->setLexicalDeclContext(D->getLexicalDeclContext());
1311 Owner->addDecl(Inst);
1313 if (!PrevClassTemplate) {
1314 // Queue up any out-of-line partial specializations of this member
1315 // class template; the client will force their instantiation once
1316 // the enclosing class has been instantiated.
1317 SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
1318 D->getPartialSpecializations(PartialSpecs);
1319 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
1320 if (PartialSpecs[I]->getFirstDecl()->isOutOfLine())
1321 OutOfLinePartialSpecs.push_back(std::make_pair(Inst, PartialSpecs[I]));
1328 TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
1329 ClassTemplatePartialSpecializationDecl *D) {
1330 ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
1332 // Lookup the already-instantiated declaration in the instantiation
1333 // of the class template and return that.
1334 DeclContext::lookup_result Found
1335 = Owner->lookup(ClassTemplate->getDeclName());
1339 ClassTemplateDecl *InstClassTemplate
1340 = dyn_cast<ClassTemplateDecl>(Found.front());
1341 if (!InstClassTemplate)
1344 if (ClassTemplatePartialSpecializationDecl *Result
1345 = InstClassTemplate->findPartialSpecInstantiatedFromMember(D))
1348 return InstantiateClassTemplatePartialSpecialization(InstClassTemplate, D);
1351 Decl *TemplateDeclInstantiator::VisitVarTemplateDecl(VarTemplateDecl *D) {
1352 assert(D->getTemplatedDecl()->isStaticDataMember() &&
1353 "Only static data member templates are allowed.");
1355 // Create a local instantiation scope for this variable template, which
1356 // will contain the instantiations of the template parameters.
1357 LocalInstantiationScope Scope(SemaRef);
1358 TemplateParameterList *TempParams = D->getTemplateParameters();
1359 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1363 VarDecl *Pattern = D->getTemplatedDecl();
1364 VarTemplateDecl *PrevVarTemplate = nullptr;
1366 if (getPreviousDeclForInstantiation(Pattern)) {
1367 DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
1369 PrevVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
1373 cast_or_null<VarDecl>(VisitVarDecl(Pattern,
1374 /*InstantiatingVarTemplate=*/true));
1375 if (!VarInst) return nullptr;
1377 DeclContext *DC = Owner;
1379 VarTemplateDecl *Inst = VarTemplateDecl::Create(
1380 SemaRef.Context, DC, D->getLocation(), D->getIdentifier(), InstParams,
1382 VarInst->setDescribedVarTemplate(Inst);
1383 Inst->setPreviousDecl(PrevVarTemplate);
1385 Inst->setAccess(D->getAccess());
1386 if (!PrevVarTemplate)
1387 Inst->setInstantiatedFromMemberTemplate(D);
1389 if (D->isOutOfLine()) {
1390 Inst->setLexicalDeclContext(D->getLexicalDeclContext());
1391 VarInst->setLexicalDeclContext(D->getLexicalDeclContext());
1394 Owner->addDecl(Inst);
1396 if (!PrevVarTemplate) {
1397 // Queue up any out-of-line partial specializations of this member
1398 // variable template; the client will force their instantiation once
1399 // the enclosing class has been instantiated.
1400 SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
1401 D->getPartialSpecializations(PartialSpecs);
1402 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
1403 if (PartialSpecs[I]->getFirstDecl()->isOutOfLine())
1404 OutOfLineVarPartialSpecs.push_back(
1405 std::make_pair(Inst, PartialSpecs[I]));
1411 Decl *TemplateDeclInstantiator::VisitVarTemplatePartialSpecializationDecl(
1412 VarTemplatePartialSpecializationDecl *D) {
1413 assert(D->isStaticDataMember() &&
1414 "Only static data member templates are allowed.");
1416 VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
1418 // Lookup the already-instantiated declaration and return that.
1419 DeclContext::lookup_result Found = Owner->lookup(VarTemplate->getDeclName());
1420 assert(!Found.empty() && "Instantiation found nothing?");
1422 VarTemplateDecl *InstVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
1423 assert(InstVarTemplate && "Instantiation did not find a variable template?");
1425 if (VarTemplatePartialSpecializationDecl *Result =
1426 InstVarTemplate->findPartialSpecInstantiatedFromMember(D))
1429 return InstantiateVarTemplatePartialSpecialization(InstVarTemplate, D);
1433 TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1434 // Create a local instantiation scope for this function template, which
1435 // will contain the instantiations of the template parameters and then get
1436 // merged with the local instantiation scope for the function template
1438 LocalInstantiationScope Scope(SemaRef);
1440 TemplateParameterList *TempParams = D->getTemplateParameters();
1441 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1445 FunctionDecl *Instantiated = nullptr;
1446 if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
1447 Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
1450 Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
1451 D->getTemplatedDecl(),
1457 // Link the instantiated function template declaration to the function
1458 // template from which it was instantiated.
1459 FunctionTemplateDecl *InstTemplate
1460 = Instantiated->getDescribedFunctionTemplate();
1461 InstTemplate->setAccess(D->getAccess());
1462 assert(InstTemplate &&
1463 "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
1465 bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
1467 // Link the instantiation back to the pattern *unless* this is a
1468 // non-definition friend declaration.
1469 if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
1470 !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
1471 InstTemplate->setInstantiatedFromMemberTemplate(D);
1473 // Make declarations visible in the appropriate context.
1475 Owner->addDecl(InstTemplate);
1476 } else if (InstTemplate->getDeclContext()->isRecord() &&
1477 !getPreviousDeclForInstantiation(D)) {
1478 SemaRef.CheckFriendAccess(InstTemplate);
1481 return InstTemplate;
1484 Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
1485 CXXRecordDecl *PrevDecl = nullptr;
1486 if (D->isInjectedClassName())
1487 PrevDecl = cast<CXXRecordDecl>(Owner);
1488 else if (CXXRecordDecl *PatternPrev = getPreviousDeclForInstantiation(D)) {
1489 NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
1492 if (!Prev) return nullptr;
1493 PrevDecl = cast<CXXRecordDecl>(Prev);
1496 CXXRecordDecl *Record
1497 = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
1498 D->getLocStart(), D->getLocation(),
1499 D->getIdentifier(), PrevDecl);
1501 // Substitute the nested name specifier, if any.
1502 if (SubstQualifier(D, Record))
1505 Record->setImplicit(D->isImplicit());
1506 // FIXME: Check against AS_none is an ugly hack to work around the issue that
1507 // the tag decls introduced by friend class declarations don't have an access
1508 // specifier. Remove once this area of the code gets sorted out.
1509 if (D->getAccess() != AS_none)
1510 Record->setAccess(D->getAccess());
1511 if (!D->isInjectedClassName())
1512 Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
1514 // If the original function was part of a friend declaration,
1515 // inherit its namespace state.
1516 if (D->getFriendObjectKind())
1517 Record->setObjectOfFriendDecl();
1519 // Make sure that anonymous structs and unions are recorded.
1520 if (D->isAnonymousStructOrUnion())
1521 Record->setAnonymousStructOrUnion(true);
1523 if (D->isLocalClass())
1524 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
1526 // Forward the mangling number from the template to the instantiated decl.
1527 SemaRef.Context.setManglingNumber(Record,
1528 SemaRef.Context.getManglingNumber(D));
1530 // See if the old tag was defined along with a declarator.
1531 // If it did, mark the new tag as being associated with that declarator.
1532 if (DeclaratorDecl *DD = SemaRef.Context.getDeclaratorForUnnamedTagDecl(D))
1533 SemaRef.Context.addDeclaratorForUnnamedTagDecl(Record, DD);
1535 // See if the old tag was defined along with a typedef.
1536 // If it did, mark the new tag as being associated with that typedef.
1537 if (TypedefNameDecl *TND = SemaRef.Context.getTypedefNameForUnnamedTagDecl(D))
1538 SemaRef.Context.addTypedefNameForUnnamedTagDecl(Record, TND);
1540 Owner->addDecl(Record);
1542 // DR1484 clarifies that the members of a local class are instantiated as part
1543 // of the instantiation of their enclosing entity.
1544 if (D->isCompleteDefinition() && D->isLocalClass()) {
1545 Sema::LocalEagerInstantiationScope LocalInstantiations(SemaRef);
1547 SemaRef.InstantiateClass(D->getLocation(), Record, D, TemplateArgs,
1548 TSK_ImplicitInstantiation,
1551 // For nested local classes, we will instantiate the members when we
1552 // reach the end of the outermost (non-nested) local class.
1553 if (!D->isCXXClassMember())
1554 SemaRef.InstantiateClassMembers(D->getLocation(), Record, TemplateArgs,
1555 TSK_ImplicitInstantiation);
1557 // This class may have local implicit instantiations that need to be
1558 // performed within this scope.
1559 LocalInstantiations.perform();
1562 SemaRef.DiagnoseUnusedNestedTypedefs(Record);
1567 /// \brief Adjust the given function type for an instantiation of the
1568 /// given declaration, to cope with modifications to the function's type that
1569 /// aren't reflected in the type-source information.
1571 /// \param D The declaration we're instantiating.
1572 /// \param TInfo The already-instantiated type.
1573 static QualType adjustFunctionTypeForInstantiation(ASTContext &Context,
1575 TypeSourceInfo *TInfo) {
1576 const FunctionProtoType *OrigFunc
1577 = D->getType()->castAs<FunctionProtoType>();
1578 const FunctionProtoType *NewFunc
1579 = TInfo->getType()->castAs<FunctionProtoType>();
1580 if (OrigFunc->getExtInfo() == NewFunc->getExtInfo())
1581 return TInfo->getType();
1583 FunctionProtoType::ExtProtoInfo NewEPI = NewFunc->getExtProtoInfo();
1584 NewEPI.ExtInfo = OrigFunc->getExtInfo();
1585 return Context.getFunctionType(NewFunc->getReturnType(),
1586 NewFunc->getParamTypes(), NewEPI);
1589 /// Normal class members are of more specific types and therefore
1590 /// don't make it here. This function serves three purposes:
1591 /// 1) instantiating function templates
1592 /// 2) substituting friend declarations
1593 /// 3) substituting deduction guide declarations for nested class templates
1594 Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
1595 TemplateParameterList *TemplateParams) {
1596 // Check whether there is already a function template specialization for
1597 // this declaration.
1598 FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1599 if (FunctionTemplate && !TemplateParams) {
1600 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1602 void *InsertPos = nullptr;
1603 FunctionDecl *SpecFunc
1604 = FunctionTemplate->findSpecialization(Innermost, InsertPos);
1606 // If we already have a function template specialization, return it.
1612 if (FunctionTemplate)
1613 isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1615 isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1617 bool MergeWithParentScope = (TemplateParams != nullptr) ||
1618 Owner->isFunctionOrMethod() ||
1619 !(isa<Decl>(Owner) &&
1620 cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1621 LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1623 SmallVector<ParmVarDecl *, 4> Params;
1624 TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
1627 QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
1629 NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1631 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1637 // If we're instantiating a local function declaration, put the result
1638 // in the enclosing namespace; otherwise we need to find the instantiated
1641 if (D->isLocalExternDecl()) {
1643 SemaRef.adjustContextForLocalExternDecl(DC);
1644 } else if (isFriend && QualifierLoc) {
1646 SS.Adopt(QualifierLoc);
1647 DC = SemaRef.computeDeclContext(SS);
1648 if (!DC) return nullptr;
1650 DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1654 DeclarationNameInfo NameInfo
1655 = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1657 FunctionDecl *Function;
1658 if (auto *DGuide = dyn_cast<CXXDeductionGuideDecl>(D)) {
1659 Function = CXXDeductionGuideDecl::Create(
1660 SemaRef.Context, DC, D->getInnerLocStart(), DGuide->isExplicit(),
1661 NameInfo, T, TInfo, D->getSourceRange().getEnd());
1662 if (DGuide->isCopyDeductionCandidate())
1663 cast<CXXDeductionGuideDecl>(Function)->setIsCopyDeductionCandidate();
1665 Function = FunctionDecl::Create(
1666 SemaRef.Context, DC, D->getInnerLocStart(), NameInfo, T, TInfo,
1667 D->getCanonicalDecl()->getStorageClass(), D->isInlineSpecified(),
1668 D->hasWrittenPrototype(), D->isConstexpr());
1669 Function->setRangeEnd(D->getSourceRange().getEnd());
1673 Function->setImplicitlyInline();
1676 Function->setQualifierInfo(QualifierLoc);
1678 if (D->isLocalExternDecl())
1679 Function->setLocalExternDecl();
1681 DeclContext *LexicalDC = Owner;
1682 if (!isFriend && D->isOutOfLine() && !D->isLocalExternDecl()) {
1683 assert(D->getDeclContext()->isFileContext());
1684 LexicalDC = D->getDeclContext();
1687 Function->setLexicalDeclContext(LexicalDC);
1689 // Attach the parameters
1690 for (unsigned P = 0; P < Params.size(); ++P)
1692 Params[P]->setOwningFunction(Function);
1693 Function->setParams(Params);
1695 if (TemplateParams) {
1696 // Our resulting instantiation is actually a function template, since we
1697 // are substituting only the outer template parameters. For example, given
1699 // template<typename T>
1701 // template<typename U> friend void f(T, U);
1706 // We are instantiating the friend function template "f" within X<int>,
1707 // which means substituting int for T, but leaving "f" as a friend function
1709 // Build the function template itself.
1710 FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1711 Function->getLocation(),
1712 Function->getDeclName(),
1713 TemplateParams, Function);
1714 Function->setDescribedFunctionTemplate(FunctionTemplate);
1716 FunctionTemplate->setLexicalDeclContext(LexicalDC);
1718 if (isFriend && D->isThisDeclarationADefinition()) {
1719 FunctionTemplate->setInstantiatedFromMemberTemplate(
1720 D->getDescribedFunctionTemplate());
1722 } else if (FunctionTemplate) {
1723 // Record this function template specialization.
1724 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1725 Function->setFunctionTemplateSpecialization(FunctionTemplate,
1726 TemplateArgumentList::CreateCopy(SemaRef.Context,
1728 /*InsertPos=*/nullptr);
1729 } else if (isFriend && D->isThisDeclarationADefinition()) {
1730 // Do not connect the friend to the template unless it's actually a
1731 // definition. We don't want non-template functions to be marked as being
1732 // template instantiations.
1733 Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1736 if (InitFunctionInstantiation(Function, D))
1737 Function->setInvalidDecl();
1739 bool isExplicitSpecialization = false;
1741 LookupResult Previous(
1742 SemaRef, Function->getDeclName(), SourceLocation(),
1743 D->isLocalExternDecl() ? Sema::LookupRedeclarationWithLinkage
1744 : Sema::LookupOrdinaryName,
1745 D->isLocalExternDecl() ? Sema::ForExternalRedeclaration
1746 : SemaRef.forRedeclarationInCurContext());
1748 if (DependentFunctionTemplateSpecializationInfo *Info
1749 = D->getDependentSpecializationInfo()) {
1750 assert(isFriend && "non-friend has dependent specialization info?");
1752 // This needs to be set now for future sanity.
1753 Function->setObjectOfFriendDecl();
1755 // Instantiate the explicit template arguments.
1756 TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1757 Info->getRAngleLoc());
1758 if (SemaRef.Subst(Info->getTemplateArgs(), Info->getNumTemplateArgs(),
1759 ExplicitArgs, TemplateArgs))
1762 // Map the candidate templates to their instantiations.
1763 for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1764 Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1765 Info->getTemplate(I),
1767 if (!Temp) return nullptr;
1769 Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1772 if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1775 Function->setInvalidDecl();
1777 isExplicitSpecialization = true;
1779 } else if (TemplateParams || !FunctionTemplate) {
1780 // Look only into the namespace where the friend would be declared to
1781 // find a previous declaration. This is the innermost enclosing namespace,
1782 // as described in ActOnFriendFunctionDecl.
1783 SemaRef.LookupQualifiedName(Previous, DC);
1785 // In C++, the previous declaration we find might be a tag type
1786 // (class or enum). In this case, the new declaration will hide the
1787 // tag type. Note that this does does not apply if we're declaring a
1788 // typedef (C++ [dcl.typedef]p4).
1789 if (Previous.isSingleTagDecl())
1794 Function->setObjectOfFriendDecl();
1796 SemaRef.CheckFunctionDeclaration(/*Scope*/ nullptr, Function, Previous,
1797 isExplicitSpecialization);
1799 NamedDecl *PrincipalDecl = (TemplateParams
1800 ? cast<NamedDecl>(FunctionTemplate)
1803 // If the original function was part of a friend declaration,
1804 // inherit its namespace state and add it to the owner.
1806 PrincipalDecl->setObjectOfFriendDecl();
1807 DC->makeDeclVisibleInContext(PrincipalDecl);
1809 bool QueuedInstantiation = false;
1811 // C++11 [temp.friend]p4 (DR329):
1812 // When a function is defined in a friend function declaration in a class
1813 // template, the function is instantiated when the function is odr-used.
1814 // The same restrictions on multiple declarations and definitions that
1815 // apply to non-template function declarations and definitions also apply
1816 // to these implicit definitions.
1817 if (D->isThisDeclarationADefinition()) {
1818 // Check for a function body.
1819 const FunctionDecl *Definition = nullptr;
1820 if (Function->isDefined(Definition) &&
1821 Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1822 SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1823 << Function->getDeclName();
1824 SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1826 // Check for redefinitions due to other instantiations of this or
1827 // a similar friend function.
1828 else for (auto R : Function->redecls()) {
1832 // If some prior declaration of this function has been used, we need
1833 // to instantiate its definition.
1834 if (!QueuedInstantiation && R->isUsed(false)) {
1835 if (MemberSpecializationInfo *MSInfo =
1836 Function->getMemberSpecializationInfo()) {
1837 if (MSInfo->getPointOfInstantiation().isInvalid()) {
1838 SourceLocation Loc = R->getLocation(); // FIXME
1839 MSInfo->setPointOfInstantiation(Loc);
1840 SemaRef.PendingLocalImplicitInstantiations.push_back(
1841 std::make_pair(Function, Loc));
1842 QueuedInstantiation = true;
1847 // If some prior declaration of this function was a friend with an
1848 // uninstantiated definition, reject it.
1849 if (R->getFriendObjectKind()) {
1850 if (const FunctionDecl *RPattern =
1851 R->getTemplateInstantiationPattern()) {
1852 if (RPattern->isDefined(RPattern)) {
1853 SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1854 << Function->getDeclName();
1855 SemaRef.Diag(R->getLocation(), diag::note_previous_definition);
1863 // Check the template parameter list against the previous declaration. The
1864 // goal here is to pick up default arguments added since the friend was
1865 // declared; we know the template parameter lists match, since otherwise
1866 // we would not have picked this template as the previous declaration.
1867 if (TemplateParams && FunctionTemplate->getPreviousDecl()) {
1868 SemaRef.CheckTemplateParameterList(
1870 FunctionTemplate->getPreviousDecl()->getTemplateParameters(),
1871 Function->isThisDeclarationADefinition()
1872 ? Sema::TPC_FriendFunctionTemplateDefinition
1873 : Sema::TPC_FriendFunctionTemplate);
1877 if (Function->isLocalExternDecl() && !Function->getPreviousDecl())
1878 DC->makeDeclVisibleInContext(PrincipalDecl);
1880 if (Function->isOverloadedOperator() && !DC->isRecord() &&
1881 PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1882 PrincipalDecl->setNonMemberOperator();
1884 assert(!D->isDefaulted() && "only methods should be defaulted");
1889 TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1890 TemplateParameterList *TemplateParams,
1891 bool IsClassScopeSpecialization) {
1892 FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1893 if (FunctionTemplate && !TemplateParams) {
1894 // We are creating a function template specialization from a function
1895 // template. Check whether there is already a function template
1896 // specialization for this particular set of template arguments.
1897 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1899 void *InsertPos = nullptr;
1900 FunctionDecl *SpecFunc
1901 = FunctionTemplate->findSpecialization(Innermost, InsertPos);
1903 // If we already have a function template specialization, return it.
1909 if (FunctionTemplate)
1910 isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1912 isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1914 bool MergeWithParentScope = (TemplateParams != nullptr) ||
1915 !(isa<Decl>(Owner) &&
1916 cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1917 LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1919 // Instantiate enclosing template arguments for friends.
1920 SmallVector<TemplateParameterList *, 4> TempParamLists;
1921 unsigned NumTempParamLists = 0;
1922 if (isFriend && (NumTempParamLists = D->getNumTemplateParameterLists())) {
1923 TempParamLists.resize(NumTempParamLists);
1924 for (unsigned I = 0; I != NumTempParamLists; ++I) {
1925 TemplateParameterList *TempParams = D->getTemplateParameterList(I);
1926 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1929 TempParamLists[I] = InstParams;
1933 SmallVector<ParmVarDecl *, 4> Params;
1934 TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
1937 QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
1939 NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1941 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1947 DeclContext *DC = Owner;
1951 SS.Adopt(QualifierLoc);
1952 DC = SemaRef.computeDeclContext(SS);
1954 if (DC && SemaRef.RequireCompleteDeclContext(SS, DC))
1957 DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1958 D->getDeclContext(),
1961 if (!DC) return nullptr;
1964 // Build the instantiated method declaration.
1965 CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1966 CXXMethodDecl *Method = nullptr;
1968 SourceLocation StartLoc = D->getInnerLocStart();
1969 DeclarationNameInfo NameInfo
1970 = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1971 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1972 Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1973 StartLoc, NameInfo, T, TInfo,
1974 Constructor->isExplicit(),
1975 Constructor->isInlineSpecified(),
1976 false, Constructor->isConstexpr());
1977 Method->setRangeEnd(Constructor->getLocEnd());
1978 } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1979 Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1980 StartLoc, NameInfo, T, TInfo,
1981 Destructor->isInlineSpecified(),
1983 Method->setRangeEnd(Destructor->getLocEnd());
1984 } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1985 Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1986 StartLoc, NameInfo, T, TInfo,
1987 Conversion->isInlineSpecified(),
1988 Conversion->isExplicit(),
1989 Conversion->isConstexpr(),
1990 Conversion->getLocEnd());
1992 StorageClass SC = D->isStatic() ? SC_Static : SC_None;
1993 Method = CXXMethodDecl::Create(SemaRef.Context, Record,
1994 StartLoc, NameInfo, T, TInfo,
1995 SC, D->isInlineSpecified(),
1996 D->isConstexpr(), D->getLocEnd());
2000 Method->setImplicitlyInline();
2003 Method->setQualifierInfo(QualifierLoc);
2005 if (TemplateParams) {
2006 // Our resulting instantiation is actually a function template, since we
2007 // are substituting only the outer template parameters. For example, given
2009 // template<typename T>
2011 // template<typename U> void f(T, U);
2016 // We are instantiating the member template "f" within X<int>, which means
2017 // substituting int for T, but leaving "f" as a member function template.
2018 // Build the function template itself.
2019 FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
2020 Method->getLocation(),
2021 Method->getDeclName(),
2022 TemplateParams, Method);
2024 FunctionTemplate->setLexicalDeclContext(Owner);
2025 FunctionTemplate->setObjectOfFriendDecl();
2026 } else if (D->isOutOfLine())
2027 FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
2028 Method->setDescribedFunctionTemplate(FunctionTemplate);
2029 } else if (FunctionTemplate) {
2030 // Record this function template specialization.
2031 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
2032 Method->setFunctionTemplateSpecialization(FunctionTemplate,
2033 TemplateArgumentList::CreateCopy(SemaRef.Context,
2035 /*InsertPos=*/nullptr);
2036 } else if (!isFriend) {
2037 // Record that this is an instantiation of a member function.
2038 Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
2041 // If we are instantiating a member function defined
2042 // out-of-line, the instantiation will have the same lexical
2043 // context (which will be a namespace scope) as the template.
2045 if (NumTempParamLists)
2046 Method->setTemplateParameterListsInfo(
2048 llvm::makeArrayRef(TempParamLists.data(), NumTempParamLists));
2050 Method->setLexicalDeclContext(Owner);
2051 Method->setObjectOfFriendDecl();
2052 } else if (D->isOutOfLine())
2053 Method->setLexicalDeclContext(D->getLexicalDeclContext());
2055 // Attach the parameters
2056 for (unsigned P = 0; P < Params.size(); ++P)
2057 Params[P]->setOwningFunction(Method);
2058 Method->setParams(Params);
2060 if (InitMethodInstantiation(Method, D))
2061 Method->setInvalidDecl();
2063 LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
2064 Sema::ForExternalRedeclaration);
2066 if (!FunctionTemplate || TemplateParams || isFriend) {
2067 SemaRef.LookupQualifiedName(Previous, Record);
2069 // In C++, the previous declaration we find might be a tag type
2070 // (class or enum). In this case, the new declaration will hide the
2071 // tag type. Note that this does does not apply if we're declaring a
2072 // typedef (C++ [dcl.typedef]p4).
2073 if (Previous.isSingleTagDecl())
2077 if (!IsClassScopeSpecialization)
2078 SemaRef.CheckFunctionDeclaration(nullptr, Method, Previous, false);
2081 SemaRef.CheckPureMethod(Method, SourceRange());
2083 // Propagate access. For a non-friend declaration, the access is
2084 // whatever we're propagating from. For a friend, it should be the
2085 // previous declaration we just found.
2086 if (isFriend && Method->getPreviousDecl())
2087 Method->setAccess(Method->getPreviousDecl()->getAccess());
2089 Method->setAccess(D->getAccess());
2090 if (FunctionTemplate)
2091 FunctionTemplate->setAccess(Method->getAccess());
2093 SemaRef.CheckOverrideControl(Method);
2095 // If a function is defined as defaulted or deleted, mark it as such now.
2096 if (D->isExplicitlyDefaulted())
2097 SemaRef.SetDeclDefaulted(Method, Method->getLocation());
2098 if (D->isDeletedAsWritten())
2099 SemaRef.SetDeclDeleted(Method, Method->getLocation());
2101 // If there's a function template, let our caller handle it.
2102 if (FunctionTemplate) {
2105 // Don't hide a (potentially) valid declaration with an invalid one.
2106 } else if (Method->isInvalidDecl() && !Previous.empty()) {
2109 // Otherwise, check access to friends and make them visible.
2110 } else if (isFriend) {
2111 // We only need to re-check access for methods which we didn't
2112 // manage to match during parsing.
2113 if (!D->getPreviousDecl())
2114 SemaRef.CheckFriendAccess(Method);
2116 Record->makeDeclVisibleInContext(Method);
2118 // Otherwise, add the declaration. We don't need to do this for
2119 // class-scope specializations because we'll have matched them with
2120 // the appropriate template.
2121 } else if (!IsClassScopeSpecialization) {
2122 Owner->addDecl(Method);
2128 Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
2129 return VisitCXXMethodDecl(D);
2132 Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
2133 return VisitCXXMethodDecl(D);
2136 Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
2137 return VisitCXXMethodDecl(D);
2140 Decl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
2141 return SemaRef.SubstParmVarDecl(D, TemplateArgs, /*indexAdjustment*/ 0, None,
2142 /*ExpectParameterPack=*/ false);
2145 Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
2146 TemplateTypeParmDecl *D) {
2147 // TODO: don't always clone when decls are refcounted.
2148 assert(D->getTypeForDecl()->isTemplateTypeParmType());
2150 TemplateTypeParmDecl *Inst = TemplateTypeParmDecl::Create(
2151 SemaRef.Context, Owner, D->getLocStart(), D->getLocation(),
2152 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(), D->getIndex(),
2153 D->getIdentifier(), D->wasDeclaredWithTypename(), D->isParameterPack());
2154 Inst->setAccess(AS_public);
2156 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2157 TypeSourceInfo *InstantiatedDefaultArg =
2158 SemaRef.SubstType(D->getDefaultArgumentInfo(), TemplateArgs,
2159 D->getDefaultArgumentLoc(), D->getDeclName());
2160 if (InstantiatedDefaultArg)
2161 Inst->setDefaultArgument(InstantiatedDefaultArg);
2164 // Introduce this template parameter's instantiation into the instantiation
2166 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
2171 Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
2172 NonTypeTemplateParmDecl *D) {
2173 // Substitute into the type of the non-type template parameter.
2174 TypeLoc TL = D->getTypeSourceInfo()->getTypeLoc();
2175 SmallVector<TypeSourceInfo *, 4> ExpandedParameterPackTypesAsWritten;
2176 SmallVector<QualType, 4> ExpandedParameterPackTypes;
2177 bool IsExpandedParameterPack = false;
2180 bool Invalid = false;
2182 if (D->isExpandedParameterPack()) {
2183 // The non-type template parameter pack is an already-expanded pack
2184 // expansion of types. Substitute into each of the expanded types.
2185 ExpandedParameterPackTypes.reserve(D->getNumExpansionTypes());
2186 ExpandedParameterPackTypesAsWritten.reserve(D->getNumExpansionTypes());
2187 for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
2188 TypeSourceInfo *NewDI =
2189 SemaRef.SubstType(D->getExpansionTypeSourceInfo(I), TemplateArgs,
2190 D->getLocation(), D->getDeclName());
2195 SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
2199 ExpandedParameterPackTypesAsWritten.push_back(NewDI);
2200 ExpandedParameterPackTypes.push_back(NewT);
2203 IsExpandedParameterPack = true;
2204 DI = D->getTypeSourceInfo();
2206 } else if (D->isPackExpansion()) {
2207 // The non-type template parameter pack's type is a pack expansion of types.
2208 // Determine whether we need to expand this parameter pack into separate
2210 PackExpansionTypeLoc Expansion = TL.castAs<PackExpansionTypeLoc>();
2211 TypeLoc Pattern = Expansion.getPatternLoc();
2212 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2213 SemaRef.collectUnexpandedParameterPacks(Pattern, Unexpanded);
2215 // Determine whether the set of unexpanded parameter packs can and should
2218 bool RetainExpansion = false;
2219 Optional<unsigned> OrigNumExpansions
2220 = Expansion.getTypePtr()->getNumExpansions();
2221 Optional<unsigned> NumExpansions = OrigNumExpansions;
2222 if (SemaRef.CheckParameterPacksForExpansion(Expansion.getEllipsisLoc(),
2223 Pattern.getSourceRange(),
2226 Expand, RetainExpansion,
2231 for (unsigned I = 0; I != *NumExpansions; ++I) {
2232 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2233 TypeSourceInfo *NewDI = SemaRef.SubstType(Pattern, TemplateArgs,
2240 SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
2244 ExpandedParameterPackTypesAsWritten.push_back(NewDI);
2245 ExpandedParameterPackTypes.push_back(NewT);
2248 // Note that we have an expanded parameter pack. The "type" of this
2249 // expanded parameter pack is the original expansion type, but callers
2250 // will end up using the expanded parameter pack types for type-checking.
2251 IsExpandedParameterPack = true;
2252 DI = D->getTypeSourceInfo();
2255 // We cannot fully expand the pack expansion now, so substitute into the
2256 // pattern and create a new pack expansion type.
2257 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2258 TypeSourceInfo *NewPattern = SemaRef.SubstType(Pattern, TemplateArgs,
2264 SemaRef.CheckNonTypeTemplateParameterType(NewPattern, D->getLocation());
2265 DI = SemaRef.CheckPackExpansion(NewPattern, Expansion.getEllipsisLoc(),
2273 // Simple case: substitution into a parameter that is not a parameter pack.
2274 DI = SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
2275 D->getLocation(), D->getDeclName());
2279 // Check that this type is acceptable for a non-type template parameter.
2280 T = SemaRef.CheckNonTypeTemplateParameterType(DI, D->getLocation());
2282 T = SemaRef.Context.IntTy;
2287 NonTypeTemplateParmDecl *Param;
2288 if (IsExpandedParameterPack)
2289 Param = NonTypeTemplateParmDecl::Create(
2290 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
2291 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2292 D->getPosition(), D->getIdentifier(), T, DI, ExpandedParameterPackTypes,
2293 ExpandedParameterPackTypesAsWritten);
2295 Param = NonTypeTemplateParmDecl::Create(
2296 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
2297 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2298 D->getPosition(), D->getIdentifier(), T, D->isParameterPack(), DI);
2300 Param->setAccess(AS_public);
2302 Param->setInvalidDecl();
2304 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2305 EnterExpressionEvaluationContext ConstantEvaluated(
2306 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
2307 ExprResult Value = SemaRef.SubstExpr(D->getDefaultArgument(), TemplateArgs);
2308 if (!Value.isInvalid())
2309 Param->setDefaultArgument(Value.get());
2312 // Introduce this template parameter's instantiation into the instantiation
2314 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
2318 static void collectUnexpandedParameterPacks(
2320 TemplateParameterList *Params,
2321 SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) {
2322 for (const auto &P : *Params) {
2323 if (P->isTemplateParameterPack())
2325 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P))
2326 S.collectUnexpandedParameterPacks(NTTP->getTypeSourceInfo()->getTypeLoc(),
2328 if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(P))
2329 collectUnexpandedParameterPacks(S, TTP->getTemplateParameters(),
2335 TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
2336 TemplateTemplateParmDecl *D) {
2337 // Instantiate the template parameter list of the template template parameter.
2338 TemplateParameterList *TempParams = D->getTemplateParameters();
2339 TemplateParameterList *InstParams;
2340 SmallVector<TemplateParameterList*, 8> ExpandedParams;
2342 bool IsExpandedParameterPack = false;
2344 if (D->isExpandedParameterPack()) {
2345 // The template template parameter pack is an already-expanded pack
2346 // expansion of template parameters. Substitute into each of the expanded
2348 ExpandedParams.reserve(D->getNumExpansionTemplateParameters());
2349 for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
2351 LocalInstantiationScope Scope(SemaRef);
2352 TemplateParameterList *Expansion =
2353 SubstTemplateParams(D->getExpansionTemplateParameters(I));
2356 ExpandedParams.push_back(Expansion);
2359 IsExpandedParameterPack = true;
2360 InstParams = TempParams;
2361 } else if (D->isPackExpansion()) {
2362 // The template template parameter pack expands to a pack of template
2363 // template parameters. Determine whether we need to expand this parameter
2364 // pack into separate parameters.
2365 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2366 collectUnexpandedParameterPacks(SemaRef, D->getTemplateParameters(),
2369 // Determine whether the set of unexpanded parameter packs can and should
2372 bool RetainExpansion = false;
2373 Optional<unsigned> NumExpansions;
2374 if (SemaRef.CheckParameterPacksForExpansion(D->getLocation(),
2375 TempParams->getSourceRange(),
2378 Expand, RetainExpansion,
2383 for (unsigned I = 0; I != *NumExpansions; ++I) {
2384 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2385 LocalInstantiationScope Scope(SemaRef);
2386 TemplateParameterList *Expansion = SubstTemplateParams(TempParams);
2389 ExpandedParams.push_back(Expansion);
2392 // Note that we have an expanded parameter pack. The "type" of this
2393 // expanded parameter pack is the original expansion type, but callers
2394 // will end up using the expanded parameter pack types for type-checking.
2395 IsExpandedParameterPack = true;
2396 InstParams = TempParams;
2398 // We cannot fully expand the pack expansion now, so just substitute
2399 // into the pattern.
2400 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2402 LocalInstantiationScope Scope(SemaRef);
2403 InstParams = SubstTemplateParams(TempParams);
2408 // Perform the actual substitution of template parameters within a new,
2409 // local instantiation scope.
2410 LocalInstantiationScope Scope(SemaRef);
2411 InstParams = SubstTemplateParams(TempParams);
2416 // Build the template template parameter.
2417 TemplateTemplateParmDecl *Param;
2418 if (IsExpandedParameterPack)
2419 Param = TemplateTemplateParmDecl::Create(
2420 SemaRef.Context, Owner, D->getLocation(),
2421 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2422 D->getPosition(), D->getIdentifier(), InstParams, ExpandedParams);
2424 Param = TemplateTemplateParmDecl::Create(
2425 SemaRef.Context, Owner, D->getLocation(),
2426 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2427 D->getPosition(), D->isParameterPack(), D->getIdentifier(), InstParams);
2428 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2429 NestedNameSpecifierLoc QualifierLoc =
2430 D->getDefaultArgument().getTemplateQualifierLoc();
2432 SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgs);
2433 TemplateName TName = SemaRef.SubstTemplateName(
2434 QualifierLoc, D->getDefaultArgument().getArgument().getAsTemplate(),
2435 D->getDefaultArgument().getTemplateNameLoc(), TemplateArgs);
2436 if (!TName.isNull())
2437 Param->setDefaultArgument(
2439 TemplateArgumentLoc(TemplateArgument(TName),
2440 D->getDefaultArgument().getTemplateQualifierLoc(),
2441 D->getDefaultArgument().getTemplateNameLoc()));
2443 Param->setAccess(AS_public);
2445 // Introduce this template parameter's instantiation into the instantiation
2447 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
2452 Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
2453 // Using directives are never dependent (and never contain any types or
2454 // expressions), so they require no explicit instantiation work.
2456 UsingDirectiveDecl *Inst
2457 = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
2458 D->getNamespaceKeyLocation(),
2459 D->getQualifierLoc(),
2460 D->getIdentLocation(),
2461 D->getNominatedNamespace(),
2462 D->getCommonAncestor());
2464 // Add the using directive to its declaration context
2465 // only if this is not a function or method.
2466 if (!Owner->isFunctionOrMethod())
2467 Owner->addDecl(Inst);
2472 Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
2474 // The nested name specifier may be dependent, for example
2475 // template <typename T> struct t {
2476 // struct s1 { T f1(); };
2477 // struct s2 : s1 { using s1::f1; };
2479 // template struct t<int>;
2480 // Here, in using s1::f1, s1 refers to t<T>::s1;
2481 // we need to substitute for t<int>::s1.
2482 NestedNameSpecifierLoc QualifierLoc
2483 = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
2488 // For an inheriting constructor declaration, the name of the using
2489 // declaration is the name of a constructor in this class, not in the
2491 DeclarationNameInfo NameInfo = D->getNameInfo();
2492 if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName)
2493 if (auto *RD = dyn_cast<CXXRecordDecl>(SemaRef.CurContext))
2494 NameInfo.setName(SemaRef.Context.DeclarationNames.getCXXConstructorName(
2495 SemaRef.Context.getCanonicalType(SemaRef.Context.getRecordType(RD))));
2497 // We only need to do redeclaration lookups if we're in a class
2498 // scope (in fact, it's not really even possible in non-class
2500 bool CheckRedeclaration = Owner->isRecord();
2502 LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
2503 Sema::ForVisibleRedeclaration);
2505 UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
2512 SS.Adopt(QualifierLoc);
2513 if (CheckRedeclaration) {
2514 Prev.setHideTags(false);
2515 SemaRef.LookupQualifiedName(Prev, Owner);
2517 // Check for invalid redeclarations.
2518 if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLoc(),
2519 D->hasTypename(), SS,
2520 D->getLocation(), Prev))
2521 NewUD->setInvalidDecl();
2525 if (!NewUD->isInvalidDecl() &&
2526 SemaRef.CheckUsingDeclQualifier(D->getUsingLoc(), D->hasTypename(),
2527 SS, NameInfo, D->getLocation()))
2528 NewUD->setInvalidDecl();
2530 SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
2531 NewUD->setAccess(D->getAccess());
2532 Owner->addDecl(NewUD);
2534 // Don't process the shadow decls for an invalid decl.
2535 if (NewUD->isInvalidDecl())
2538 if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName)
2539 SemaRef.CheckInheritingConstructorUsingDecl(NewUD);
2541 bool isFunctionScope = Owner->isFunctionOrMethod();
2543 // Process the shadow decls.
2544 for (auto *Shadow : D->shadows()) {
2545 // FIXME: UsingShadowDecl doesn't preserve its immediate target, so
2546 // reconstruct it in the case where it matters.
2547 NamedDecl *OldTarget = Shadow->getTargetDecl();
2548 if (auto *CUSD = dyn_cast<ConstructorUsingShadowDecl>(Shadow))
2549 if (auto *BaseShadow = CUSD->getNominatedBaseClassShadowDecl())
2550 OldTarget = BaseShadow;
2552 NamedDecl *InstTarget =
2553 cast_or_null<NamedDecl>(SemaRef.FindInstantiatedDecl(
2554 Shadow->getLocation(), OldTarget, TemplateArgs));
2558 UsingShadowDecl *PrevDecl = nullptr;
2559 if (CheckRedeclaration) {
2560 if (SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev, PrevDecl))
2562 } else if (UsingShadowDecl *OldPrev =
2563 getPreviousDeclForInstantiation(Shadow)) {
2564 PrevDecl = cast_or_null<UsingShadowDecl>(SemaRef.FindInstantiatedDecl(
2565 Shadow->getLocation(), OldPrev, TemplateArgs));
2568 UsingShadowDecl *InstShadow =
2569 SemaRef.BuildUsingShadowDecl(/*Scope*/nullptr, NewUD, InstTarget,
2571 SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
2573 if (isFunctionScope)
2574 SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
2580 Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
2581 // Ignore these; we handle them in bulk when processing the UsingDecl.
2585 Decl *TemplateDeclInstantiator::VisitConstructorUsingShadowDecl(
2586 ConstructorUsingShadowDecl *D) {
2587 // Ignore these; we handle them in bulk when processing the UsingDecl.
2591 template <typename T>
2592 Decl *TemplateDeclInstantiator::instantiateUnresolvedUsingDecl(
2593 T *D, bool InstantiatingPackElement) {
2594 // If this is a pack expansion, expand it now.
2595 if (D->isPackExpansion() && !InstantiatingPackElement) {
2596 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2597 SemaRef.collectUnexpandedParameterPacks(D->getQualifierLoc(), Unexpanded);
2598 SemaRef.collectUnexpandedParameterPacks(D->getNameInfo(), Unexpanded);
2600 // Determine whether the set of unexpanded parameter packs can and should
2603 bool RetainExpansion = false;
2604 Optional<unsigned> NumExpansions;
2605 if (SemaRef.CheckParameterPacksForExpansion(
2606 D->getEllipsisLoc(), D->getSourceRange(), Unexpanded, TemplateArgs,
2607 Expand, RetainExpansion, NumExpansions))
2610 // This declaration cannot appear within a function template signature,
2611 // so we can't have a partial argument list for a parameter pack.
2612 assert(!RetainExpansion &&
2613 "should never need to retain an expansion for UsingPackDecl");
2616 // We cannot fully expand the pack expansion now, so substitute into the
2617 // pattern and create a new pack expansion.
2618 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2619 return instantiateUnresolvedUsingDecl(D, true);
2622 // Within a function, we don't have any normal way to check for conflicts
2623 // between shadow declarations from different using declarations in the
2624 // same pack expansion, but this is always ill-formed because all expansions
2625 // must produce (conflicting) enumerators.
2627 // Sadly we can't just reject this in the template definition because it
2628 // could be valid if the pack is empty or has exactly one expansion.
2629 if (D->getDeclContext()->isFunctionOrMethod() && *NumExpansions > 1) {
2630 SemaRef.Diag(D->getEllipsisLoc(),
2631 diag::err_using_decl_redeclaration_expansion);
2635 // Instantiate the slices of this pack and build a UsingPackDecl.
2636 SmallVector<NamedDecl*, 8> Expansions;
2637 for (unsigned I = 0; I != *NumExpansions; ++I) {
2638 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2639 Decl *Slice = instantiateUnresolvedUsingDecl(D, true);
2642 // Note that we can still get unresolved using declarations here, if we
2643 // had arguments for all packs but the pattern also contained other
2644 // template arguments (this only happens during partial substitution, eg
2645 // into the body of a generic lambda in a function template).
2646 Expansions.push_back(cast<NamedDecl>(Slice));
2649 auto *NewD = SemaRef.BuildUsingPackDecl(D, Expansions);
2650 if (isDeclWithinFunction(D))
2651 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewD);
2655 UnresolvedUsingTypenameDecl *TD = dyn_cast<UnresolvedUsingTypenameDecl>(D);
2656 SourceLocation TypenameLoc = TD ? TD->getTypenameLoc() : SourceLocation();
2658 NestedNameSpecifierLoc QualifierLoc
2659 = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
2665 SS.Adopt(QualifierLoc);
2667 DeclarationNameInfo NameInfo
2668 = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
2670 // Produce a pack expansion only if we're not instantiating a particular
2671 // slice of a pack expansion.
2672 bool InstantiatingSlice = D->getEllipsisLoc().isValid() &&
2673 SemaRef.ArgumentPackSubstitutionIndex != -1;
2674 SourceLocation EllipsisLoc =
2675 InstantiatingSlice ? SourceLocation() : D->getEllipsisLoc();
2677 NamedDecl *UD = SemaRef.BuildUsingDeclaration(
2678 /*Scope*/ nullptr, D->getAccess(), D->getUsingLoc(),
2679 /*HasTypename*/ TD, TypenameLoc, SS, NameInfo, EllipsisLoc, nullptr,
2680 /*IsInstantiation*/ true);
2682 SemaRef.Context.setInstantiatedFromUsingDecl(UD, D);
2687 Decl *TemplateDeclInstantiator::VisitUnresolvedUsingTypenameDecl(
2688 UnresolvedUsingTypenameDecl *D) {
2689 return instantiateUnresolvedUsingDecl(D);
2692 Decl *TemplateDeclInstantiator::VisitUnresolvedUsingValueDecl(
2693 UnresolvedUsingValueDecl *D) {
2694 return instantiateUnresolvedUsingDecl(D);
2697 Decl *TemplateDeclInstantiator::VisitUsingPackDecl(UsingPackDecl *D) {
2698 SmallVector<NamedDecl*, 8> Expansions;
2699 for (auto *UD : D->expansions()) {
2701 SemaRef.FindInstantiatedDecl(D->getLocation(), UD, TemplateArgs))
2702 Expansions.push_back(cast<NamedDecl>(NewUD));
2707 auto *NewD = SemaRef.BuildUsingPackDecl(D, Expansions);
2708 if (isDeclWithinFunction(D))
2709 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewD);
2713 Decl *TemplateDeclInstantiator::VisitClassScopeFunctionSpecializationDecl(
2714 ClassScopeFunctionSpecializationDecl *Decl) {
2715 CXXMethodDecl *OldFD = Decl->getSpecialization();
2716 CXXMethodDecl *NewFD =
2717 cast_or_null<CXXMethodDecl>(VisitCXXMethodDecl(OldFD, nullptr, true));
2721 LookupResult Previous(SemaRef, NewFD->getNameInfo(), Sema::LookupOrdinaryName,
2722 Sema::ForExternalRedeclaration);
2724 TemplateArgumentListInfo TemplateArgs;
2725 TemplateArgumentListInfo *TemplateArgsPtr = nullptr;
2726 if (Decl->hasExplicitTemplateArgs()) {
2727 TemplateArgs = Decl->templateArgs();
2728 TemplateArgsPtr = &TemplateArgs;
2731 SemaRef.LookupQualifiedName(Previous, SemaRef.CurContext);
2732 if (SemaRef.CheckFunctionTemplateSpecialization(NewFD, TemplateArgsPtr,
2734 NewFD->setInvalidDecl();
2738 // Associate the specialization with the pattern.
2739 FunctionDecl *Specialization = cast<FunctionDecl>(Previous.getFoundDecl());
2740 assert(Specialization && "Class scope Specialization is null");
2741 SemaRef.Context.setClassScopeSpecializationPattern(Specialization, OldFD);
2746 Decl *TemplateDeclInstantiator::VisitOMPThreadPrivateDecl(
2747 OMPThreadPrivateDecl *D) {
2748 SmallVector<Expr *, 5> Vars;
2749 for (auto *I : D->varlists()) {
2750 Expr *Var = SemaRef.SubstExpr(I, TemplateArgs).get();
2751 assert(isa<DeclRefExpr>(Var) && "threadprivate arg is not a DeclRefExpr");
2752 Vars.push_back(Var);
2755 OMPThreadPrivateDecl *TD =
2756 SemaRef.CheckOMPThreadPrivateDecl(D->getLocation(), Vars);
2758 TD->setAccess(AS_public);
2764 Decl *TemplateDeclInstantiator::VisitOMPDeclareReductionDecl(
2765 OMPDeclareReductionDecl *D) {
2766 // Instantiate type and check if it is allowed.
2767 QualType SubstReductionType = SemaRef.ActOnOpenMPDeclareReductionType(
2769 ParsedType::make(SemaRef.SubstType(D->getType(), TemplateArgs,
2770 D->getLocation(), DeclarationName())));
2771 if (SubstReductionType.isNull())
2773 bool IsCorrect = !SubstReductionType.isNull();
2774 // Create instantiated copy.
2775 std::pair<QualType, SourceLocation> ReductionTypes[] = {
2776 std::make_pair(SubstReductionType, D->getLocation())};
2777 auto *PrevDeclInScope = D->getPrevDeclInScope();
2778 if (PrevDeclInScope && !PrevDeclInScope->isInvalidDecl()) {
2779 PrevDeclInScope = cast<OMPDeclareReductionDecl>(
2780 SemaRef.CurrentInstantiationScope->findInstantiationOf(PrevDeclInScope)
2783 auto DRD = SemaRef.ActOnOpenMPDeclareReductionDirectiveStart(
2784 /*S=*/nullptr, Owner, D->getDeclName(), ReductionTypes, D->getAccess(),
2786 auto *NewDRD = cast<OMPDeclareReductionDecl>(DRD.get().getSingleDecl());
2787 if (isDeclWithinFunction(NewDRD))
2788 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewDRD);
2789 Expr *SubstCombiner = nullptr;
2790 Expr *SubstInitializer = nullptr;
2791 // Combiners instantiation sequence.
2792 if (D->getCombiner()) {
2793 SemaRef.ActOnOpenMPDeclareReductionCombinerStart(
2794 /*S=*/nullptr, NewDRD);
2795 const char *Names[] = {"omp_in", "omp_out"};
2796 for (auto &Name : Names) {
2797 DeclarationName DN(&SemaRef.Context.Idents.get(Name));
2798 auto OldLookup = D->lookup(DN);
2799 auto Lookup = NewDRD->lookup(DN);
2800 if (!OldLookup.empty() && !Lookup.empty()) {
2801 assert(Lookup.size() == 1 && OldLookup.size() == 1);
2802 SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldLookup.front(),
2806 SubstCombiner = SemaRef.SubstExpr(D->getCombiner(), TemplateArgs).get();
2807 SemaRef.ActOnOpenMPDeclareReductionCombinerEnd(NewDRD, SubstCombiner);
2808 // Initializers instantiation sequence.
2809 if (D->getInitializer()) {
2810 VarDecl *OmpPrivParm =
2811 SemaRef.ActOnOpenMPDeclareReductionInitializerStart(
2812 /*S=*/nullptr, NewDRD);
2813 const char *Names[] = {"omp_orig", "omp_priv"};
2814 for (auto &Name : Names) {
2815 DeclarationName DN(&SemaRef.Context.Idents.get(Name));
2816 auto OldLookup = D->lookup(DN);
2817 auto Lookup = NewDRD->lookup(DN);
2818 if (!OldLookup.empty() && !Lookup.empty()) {
2819 assert(Lookup.size() == 1 && OldLookup.size() == 1);
2820 auto *OldVD = cast<VarDecl>(OldLookup.front());
2821 auto *NewVD = cast<VarDecl>(Lookup.front());
2822 SemaRef.InstantiateVariableInitializer(NewVD, OldVD, TemplateArgs);
2823 SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldVD, NewVD);
2826 if (D->getInitializerKind() == OMPDeclareReductionDecl::CallInit) {
2828 SemaRef.SubstExpr(D->getInitializer(), TemplateArgs).get();
2830 IsCorrect = IsCorrect && OmpPrivParm->hasInit();
2832 SemaRef.ActOnOpenMPDeclareReductionInitializerEnd(
2833 NewDRD, SubstInitializer, OmpPrivParm);
2836 IsCorrect && SubstCombiner &&
2837 (!D->getInitializer() ||
2838 (D->getInitializerKind() == OMPDeclareReductionDecl::CallInit &&
2839 SubstInitializer) ||
2840 (D->getInitializerKind() != OMPDeclareReductionDecl::CallInit &&
2841 !SubstInitializer && !SubstInitializer));
2845 (void)SemaRef.ActOnOpenMPDeclareReductionDirectiveEnd(/*S=*/nullptr, DRD,
2851 Decl *TemplateDeclInstantiator::VisitOMPCapturedExprDecl(
2852 OMPCapturedExprDecl * /*D*/) {
2853 llvm_unreachable("Should not be met in templates");
2856 Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D) {
2857 return VisitFunctionDecl(D, nullptr);
2861 TemplateDeclInstantiator::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
2862 return VisitFunctionDecl(D, nullptr);
2865 Decl *TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D) {
2866 return VisitCXXMethodDecl(D, nullptr);
2869 Decl *TemplateDeclInstantiator::VisitRecordDecl(RecordDecl *D) {
2870 llvm_unreachable("There are only CXXRecordDecls in C++");
2874 TemplateDeclInstantiator::VisitClassTemplateSpecializationDecl(
2875 ClassTemplateSpecializationDecl *D) {
2876 // As a MS extension, we permit class-scope explicit specialization
2877 // of member class templates.
2878 ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
2879 assert(ClassTemplate->getDeclContext()->isRecord() &&
2880 D->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
2881 "can only instantiate an explicit specialization "
2882 "for a member class template");
2884 // Lookup the already-instantiated declaration in the instantiation
2885 // of the class template. FIXME: Diagnose or assert if this fails?
2886 DeclContext::lookup_result Found
2887 = Owner->lookup(ClassTemplate->getDeclName());
2890 ClassTemplateDecl *InstClassTemplate
2891 = dyn_cast<ClassTemplateDecl>(Found.front());
2892 if (!InstClassTemplate)
2895 // Substitute into the template arguments of the class template explicit
2897 TemplateSpecializationTypeLoc Loc = D->getTypeAsWritten()->getTypeLoc().
2898 castAs<TemplateSpecializationTypeLoc>();
2899 TemplateArgumentListInfo InstTemplateArgs(Loc.getLAngleLoc(),
2900 Loc.getRAngleLoc());
2901 SmallVector<TemplateArgumentLoc, 4> ArgLocs;
2902 for (unsigned I = 0; I != Loc.getNumArgs(); ++I)
2903 ArgLocs.push_back(Loc.getArgLoc(I));
2904 if (SemaRef.Subst(ArgLocs.data(), ArgLocs.size(),
2905 InstTemplateArgs, TemplateArgs))
2908 // Check that the template argument list is well-formed for this
2910 SmallVector<TemplateArgument, 4> Converted;
2911 if (SemaRef.CheckTemplateArgumentList(InstClassTemplate,
2918 // Figure out where to insert this class template explicit specialization
2919 // in the member template's set of class template explicit specializations.
2920 void *InsertPos = nullptr;
2921 ClassTemplateSpecializationDecl *PrevDecl =
2922 InstClassTemplate->findSpecialization(Converted, InsertPos);
2924 // Check whether we've already seen a conflicting instantiation of this
2925 // declaration (for instance, if there was a prior implicit instantiation).
2928 SemaRef.CheckSpecializationInstantiationRedecl(D->getLocation(),
2929 D->getSpecializationKind(),
2931 PrevDecl->getSpecializationKind(),
2932 PrevDecl->getPointOfInstantiation(),
2936 // If PrevDecl was a definition and D is also a definition, diagnose.
2937 // This happens in cases like:
2939 // template<typename T, typename U>
2941 // template<typename X> struct Inner;
2942 // template<> struct Inner<T> {};
2943 // template<> struct Inner<U> {};
2946 // Outer<int, int> outer; // error: the explicit specializations of Inner
2947 // // have the same signature.
2948 if (PrevDecl && PrevDecl->getDefinition() &&
2949 D->isThisDeclarationADefinition()) {
2950 SemaRef.Diag(D->getLocation(), diag::err_redefinition) << PrevDecl;
2951 SemaRef.Diag(PrevDecl->getDefinition()->getLocation(),
2952 diag::note_previous_definition);
2956 // Create the class template partial specialization declaration.
2957 ClassTemplateSpecializationDecl *InstD
2958 = ClassTemplateSpecializationDecl::Create(SemaRef.Context,
2967 // Add this partial specialization to the set of class template partial
2970 InstClassTemplate->AddSpecialization(InstD, InsertPos);
2972 // Substitute the nested name specifier, if any.
2973 if (SubstQualifier(D, InstD))
2976 // Build the canonical type that describes the converted template
2977 // arguments of the class template explicit specialization.
2978 QualType CanonType = SemaRef.Context.getTemplateSpecializationType(
2979 TemplateName(InstClassTemplate), Converted,
2980 SemaRef.Context.getRecordType(InstD));
2982 // Build the fully-sugared type for this class template
2983 // specialization as the user wrote in the specialization
2984 // itself. This means that we'll pretty-print the type retrieved
2985 // from the specialization's declaration the way that the user
2986 // actually wrote the specialization, rather than formatting the
2987 // name based on the "canonical" representation used to store the
2988 // template arguments in the specialization.
2989 TypeSourceInfo *WrittenTy = SemaRef.Context.getTemplateSpecializationTypeInfo(
2990 TemplateName(InstClassTemplate), D->getLocation(), InstTemplateArgs,
2993 InstD->setAccess(D->getAccess());
2994 InstD->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
2995 InstD->setSpecializationKind(D->getSpecializationKind());
2996 InstD->setTypeAsWritten(WrittenTy);
2997 InstD->setExternLoc(D->getExternLoc());
2998 InstD->setTemplateKeywordLoc(D->getTemplateKeywordLoc());
3000 Owner->addDecl(InstD);
3002 // Instantiate the members of the class-scope explicit specialization eagerly.
3003 // We don't have support for lazy instantiation of an explicit specialization
3004 // yet, and MSVC eagerly instantiates in this case.
3005 if (D->isThisDeclarationADefinition() &&
3006 SemaRef.InstantiateClass(D->getLocation(), InstD, D, TemplateArgs,
3007 TSK_ImplicitInstantiation,
3014 Decl *TemplateDeclInstantiator::VisitVarTemplateSpecializationDecl(
3015 VarTemplateSpecializationDecl *D) {
3017 TemplateArgumentListInfo VarTemplateArgsInfo;
3018 VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
3019 assert(VarTemplate &&
3020 "A template specialization without specialized template?");
3022 // Substitute the current template arguments.
3023 const TemplateArgumentListInfo &TemplateArgsInfo = D->getTemplateArgsInfo();
3024 VarTemplateArgsInfo.setLAngleLoc(TemplateArgsInfo.getLAngleLoc());
3025 VarTemplateArgsInfo.setRAngleLoc(TemplateArgsInfo.getRAngleLoc());
3027 if (SemaRef.Subst(TemplateArgsInfo.getArgumentArray(),
3028 TemplateArgsInfo.size(), VarTemplateArgsInfo, TemplateArgs))
3031 // Check that the template argument list is well-formed for this template.
3032 SmallVector<TemplateArgument, 4> Converted;
3033 if (SemaRef.CheckTemplateArgumentList(
3034 VarTemplate, VarTemplate->getLocStart(),
3035 const_cast<TemplateArgumentListInfo &>(VarTemplateArgsInfo), false,
3039 // Find the variable template specialization declaration that
3040 // corresponds to these arguments.
3041 void *InsertPos = nullptr;
3042 if (VarTemplateSpecializationDecl *VarSpec = VarTemplate->findSpecialization(
3043 Converted, InsertPos))
3044 // If we already have a variable template specialization, return it.
3047 return VisitVarTemplateSpecializationDecl(VarTemplate, D, InsertPos,
3048 VarTemplateArgsInfo, Converted);
3051 Decl *TemplateDeclInstantiator::VisitVarTemplateSpecializationDecl(
3052 VarTemplateDecl *VarTemplate, VarDecl *D, void *InsertPos,
3053 const TemplateArgumentListInfo &TemplateArgsInfo,
3054 ArrayRef<TemplateArgument> Converted) {
3056 // Do substitution on the type of the declaration
3057 TypeSourceInfo *DI =
3058 SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
3059 D->getTypeSpecStartLoc(), D->getDeclName());
3063 if (DI->getType()->isFunctionType()) {
3064 SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
3065 << D->isStaticDataMember() << DI->getType();
3069 // Build the instantiated declaration
3070 VarTemplateSpecializationDecl *Var = VarTemplateSpecializationDecl::Create(
3071 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
3072 VarTemplate, DI->getType(), DI, D->getStorageClass(), Converted);
3073 Var->setTemplateArgsInfo(TemplateArgsInfo);
3075 VarTemplate->AddSpecialization(Var, InsertPos);
3077 // Substitute the nested name specifier, if any.
3078 if (SubstQualifier(D, Var))
3081 SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs,
3082 Owner, StartingScope);
3087 Decl *TemplateDeclInstantiator::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
3088 llvm_unreachable("@defs is not supported in Objective-C++");
3091 Decl *TemplateDeclInstantiator::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
3092 // FIXME: We need to be able to instantiate FriendTemplateDecls.
3093 unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
3094 DiagnosticsEngine::Error,
3095 "cannot instantiate %0 yet");
3096 SemaRef.Diag(D->getLocation(), DiagID)
3097 << D->getDeclKindName();
3102 Decl *TemplateDeclInstantiator::VisitDecl(Decl *D) {
3103 llvm_unreachable("Unexpected decl");
3106 Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
3107 const MultiLevelTemplateArgumentList &TemplateArgs) {
3108 TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
3109 if (D->isInvalidDecl())
3112 return Instantiator.Visit(D);
3115 /// \brief Instantiates a nested template parameter list in the current
3116 /// instantiation context.
3118 /// \param L The parameter list to instantiate
3120 /// \returns NULL if there was an error
3121 TemplateParameterList *
3122 TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
3123 // Get errors for all the parameters before bailing out.
3124 bool Invalid = false;
3126 unsigned N = L->size();
3127 typedef SmallVector<NamedDecl *, 8> ParamVector;
3130 for (auto &P : *L) {
3131 NamedDecl *D = cast_or_null<NamedDecl>(Visit(P));
3132 Params.push_back(D);
3133 Invalid = Invalid || !D || D->isInvalidDecl();
3136 // Clean up if we had an error.
3140 // Note: we substitute into associated constraints later
3141 Expr *const UninstantiatedRequiresClause = L->getRequiresClause();
3143 TemplateParameterList *InstL
3144 = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
3145 L->getLAngleLoc(), Params,
3147 UninstantiatedRequiresClause);
3151 /// \brief Instantiate the declaration of a class template partial
3154 /// \param ClassTemplate the (instantiated) class template that is partially
3155 // specialized by the instantiation of \p PartialSpec.
3157 /// \param PartialSpec the (uninstantiated) class template partial
3158 /// specialization that we are instantiating.
3160 /// \returns The instantiated partial specialization, if successful; otherwise,
3161 /// NULL to indicate an error.
3162 ClassTemplatePartialSpecializationDecl *
3163 TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
3164 ClassTemplateDecl *ClassTemplate,
3165 ClassTemplatePartialSpecializationDecl *PartialSpec) {
3166 // Create a local instantiation scope for this class template partial
3167 // specialization, which will contain the instantiations of the template
3169 LocalInstantiationScope Scope(SemaRef);
3171 // Substitute into the template parameters of the class template partial
3173 TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
3174 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
3178 // Substitute into the template arguments of the class template partial
3180 const ASTTemplateArgumentListInfo *TemplArgInfo
3181 = PartialSpec->getTemplateArgsAsWritten();
3182 TemplateArgumentListInfo InstTemplateArgs(TemplArgInfo->LAngleLoc,
3183 TemplArgInfo->RAngleLoc);
3184 if (SemaRef.Subst(TemplArgInfo->getTemplateArgs(),
3185 TemplArgInfo->NumTemplateArgs,
3186 InstTemplateArgs, TemplateArgs))
3189 // Check that the template argument list is well-formed for this
3191 SmallVector<TemplateArgument, 4> Converted;
3192 if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
3193 PartialSpec->getLocation(),
3199 // Check these arguments are valid for a template partial specialization.
3200 if (SemaRef.CheckTemplatePartialSpecializationArgs(
3201 PartialSpec->getLocation(), ClassTemplate, InstTemplateArgs.size(),
3205 // Figure out where to insert this class template partial specialization
3206 // in the member template's set of class template partial specializations.
3207 void *InsertPos = nullptr;
3208 ClassTemplateSpecializationDecl *PrevDecl
3209 = ClassTemplate->findPartialSpecialization(Converted, InsertPos);
3211 // Build the canonical type that describes the converted template
3212 // arguments of the class template partial specialization.
3214 = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
3217 // Build the fully-sugared type for this class template
3218 // specialization as the user wrote in the specialization
3219 // itself. This means that we'll pretty-print the type retrieved
3220 // from the specialization's declaration the way that the user
3221 // actually wrote the specialization, rather than formatting the
3222 // name based on the "canonical" representation used to store the
3223 // template arguments in the specialization.
3224 TypeSourceInfo *WrittenTy
3225 = SemaRef.Context.getTemplateSpecializationTypeInfo(
3226 TemplateName(ClassTemplate),
3227 PartialSpec->getLocation(),
3232 // We've already seen a partial specialization with the same template
3233 // parameters and template arguments. This can happen, for example, when
3234 // substituting the outer template arguments ends up causing two
3235 // class template partial specializations of a member class template
3236 // to have identical forms, e.g.,
3238 // template<typename T, typename U>
3240 // template<typename X, typename Y> struct Inner;
3241 // template<typename Y> struct Inner<T, Y>;
3242 // template<typename Y> struct Inner<U, Y>;
3245 // Outer<int, int> outer; // error: the partial specializations of Inner
3246 // // have the same signature.
3247 SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
3248 << WrittenTy->getType();
3249 SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
3250 << SemaRef.Context.getTypeDeclType(PrevDecl);
3255 // Create the class template partial specialization declaration.
3256 ClassTemplatePartialSpecializationDecl *InstPartialSpec
3257 = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
3258 PartialSpec->getTagKind(),
3260 PartialSpec->getLocStart(),
3261 PartialSpec->getLocation(),
3268 // Substitute the nested name specifier, if any.
3269 if (SubstQualifier(PartialSpec, InstPartialSpec))
3272 InstPartialSpec->setInstantiatedFromMember(PartialSpec);
3273 InstPartialSpec->setTypeAsWritten(WrittenTy);
3275 // Check the completed partial specialization.
3276 SemaRef.CheckTemplatePartialSpecialization(InstPartialSpec);
3278 // Add this partial specialization to the set of class template partial
3280 ClassTemplate->AddPartialSpecialization(InstPartialSpec,
3281 /*InsertPos=*/nullptr);
3282 return InstPartialSpec;
3285 /// \brief Instantiate the declaration of a variable template partial
3288 /// \param VarTemplate the (instantiated) variable template that is partially
3289 /// specialized by the instantiation of \p PartialSpec.
3291 /// \param PartialSpec the (uninstantiated) variable template partial
3292 /// specialization that we are instantiating.
3294 /// \returns The instantiated partial specialization, if successful; otherwise,
3295 /// NULL to indicate an error.
3296 VarTemplatePartialSpecializationDecl *
3297 TemplateDeclInstantiator::InstantiateVarTemplatePartialSpecialization(
3298 VarTemplateDecl *VarTemplate,
3299 VarTemplatePartialSpecializationDecl *PartialSpec) {
3300 // Create a local instantiation scope for this variable template partial
3301 // specialization, which will contain the instantiations of the template
3303 LocalInstantiationScope Scope(SemaRef);
3305 // Substitute into the template parameters of the variable template partial
3307 TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
3308 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
3312 // Substitute into the template arguments of the variable template partial
3314 const ASTTemplateArgumentListInfo *TemplArgInfo
3315 = PartialSpec->getTemplateArgsAsWritten();
3316 TemplateArgumentListInfo InstTemplateArgs(TemplArgInfo->LAngleLoc,
3317 TemplArgInfo->RAngleLoc);
3318 if (SemaRef.Subst(TemplArgInfo->getTemplateArgs(),
3319 TemplArgInfo->NumTemplateArgs,
3320 InstTemplateArgs, TemplateArgs))
3323 // Check that the template argument list is well-formed for this
3325 SmallVector<TemplateArgument, 4> Converted;
3326 if (SemaRef.CheckTemplateArgumentList(VarTemplate, PartialSpec->getLocation(),
3327 InstTemplateArgs, false, Converted))
3330 // Check these arguments are valid for a template partial specialization.
3331 if (SemaRef.CheckTemplatePartialSpecializationArgs(
3332 PartialSpec->getLocation(), VarTemplate, InstTemplateArgs.size(),
3336 // Figure out where to insert this variable template partial specialization
3337 // in the member template's set of variable template partial specializations.
3338 void *InsertPos = nullptr;
3339 VarTemplateSpecializationDecl *PrevDecl =
3340 VarTemplate->findPartialSpecialization(Converted, InsertPos);
3342 // Build the canonical type that describes the converted template
3343 // arguments of the variable template partial specialization.
3344 QualType CanonType = SemaRef.Context.getTemplateSpecializationType(
3345 TemplateName(VarTemplate), Converted);
3347 // Build the fully-sugared type for this variable template
3348 // specialization as the user wrote in the specialization
3349 // itself. This means that we'll pretty-print the type retrieved
3350 // from the specialization's declaration the way that the user
3351 // actually wrote the specialization, rather than formatting the
3352 // name based on the "canonical" representation used to store the
3353 // template arguments in the specialization.
3354 TypeSourceInfo *WrittenTy = SemaRef.Context.getTemplateSpecializationTypeInfo(
3355 TemplateName(VarTemplate), PartialSpec->getLocation(), InstTemplateArgs,
3359 // We've already seen a partial specialization with the same template
3360 // parameters and template arguments. This can happen, for example, when
3361 // substituting the outer template arguments ends up causing two
3362 // variable template partial specializations of a member variable template
3363 // to have identical forms, e.g.,
3365 // template<typename T, typename U>
3367 // template<typename X, typename Y> pair<X,Y> p;
3368 // template<typename Y> pair<T, Y> p;
3369 // template<typename Y> pair<U, Y> p;
3372 // Outer<int, int> outer; // error: the partial specializations of Inner
3373 // // have the same signature.
3374 SemaRef.Diag(PartialSpec->getLocation(),
3375 diag::err_var_partial_spec_redeclared)
3376 << WrittenTy->getType();
3377 SemaRef.Diag(PrevDecl->getLocation(),
3378 diag::note_var_prev_partial_spec_here);
3382 // Do substitution on the type of the declaration
3383 TypeSourceInfo *DI = SemaRef.SubstType(
3384 PartialSpec->getTypeSourceInfo(), TemplateArgs,
3385 PartialSpec->getTypeSpecStartLoc(), PartialSpec->getDeclName());
3389 if (DI->getType()->isFunctionType()) {
3390 SemaRef.Diag(PartialSpec->getLocation(),
3391 diag::err_variable_instantiates_to_function)
3392 << PartialSpec->isStaticDataMember() << DI->getType();
3396 // Create the variable template partial specialization declaration.
3397 VarTemplatePartialSpecializationDecl *InstPartialSpec =
3398 VarTemplatePartialSpecializationDecl::Create(
3399 SemaRef.Context, Owner, PartialSpec->getInnerLocStart(),
3400 PartialSpec->getLocation(), InstParams, VarTemplate, DI->getType(),
3401 DI, PartialSpec->getStorageClass(), Converted, InstTemplateArgs);
3403 // Substitute the nested name specifier, if any.
3404 if (SubstQualifier(PartialSpec, InstPartialSpec))
3407 InstPartialSpec->setInstantiatedFromMember(PartialSpec);
3408 InstPartialSpec->setTypeAsWritten(WrittenTy);
3410 // Check the completed partial specialization.
3411 SemaRef.CheckTemplatePartialSpecialization(InstPartialSpec);
3413 // Add this partial specialization to the set of variable template partial
3414 // specializations. The instantiation of the initializer is not necessary.
3415 VarTemplate->AddPartialSpecialization(InstPartialSpec, /*InsertPos=*/nullptr);
3417 SemaRef.BuildVariableInstantiation(InstPartialSpec, PartialSpec, TemplateArgs,
3418 LateAttrs, Owner, StartingScope);
3420 return InstPartialSpec;
3424 TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
3425 SmallVectorImpl<ParmVarDecl *> &Params) {
3426 TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
3427 assert(OldTInfo && "substituting function without type source info");
3428 assert(Params.empty() && "parameter vector is non-empty at start");
3430 CXXRecordDecl *ThisContext = nullptr;
3431 unsigned ThisTypeQuals = 0;
3432 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
3433 ThisContext = cast<CXXRecordDecl>(Owner);
3434 ThisTypeQuals = Method->getTypeQualifiers();
3437 TypeSourceInfo *NewTInfo
3438 = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
3439 D->getTypeSpecStartLoc(),
3441 ThisContext, ThisTypeQuals);
3445 TypeLoc OldTL = OldTInfo->getTypeLoc().IgnoreParens();
3446 if (FunctionProtoTypeLoc OldProtoLoc = OldTL.getAs<FunctionProtoTypeLoc>()) {
3447 if (NewTInfo != OldTInfo) {
3448 // Get parameters from the new type info.
3449 TypeLoc NewTL = NewTInfo->getTypeLoc().IgnoreParens();
3450 FunctionProtoTypeLoc NewProtoLoc = NewTL.castAs<FunctionProtoTypeLoc>();
3451 unsigned NewIdx = 0;
3452 for (unsigned OldIdx = 0, NumOldParams = OldProtoLoc.getNumParams();
3453 OldIdx != NumOldParams; ++OldIdx) {
3454 ParmVarDecl *OldParam = OldProtoLoc.getParam(OldIdx);
3455 LocalInstantiationScope *Scope = SemaRef.CurrentInstantiationScope;
3457 Optional<unsigned> NumArgumentsInExpansion;
3458 if (OldParam->isParameterPack())
3459 NumArgumentsInExpansion =
3460 SemaRef.getNumArgumentsInExpansion(OldParam->getType(),
3462 if (!NumArgumentsInExpansion) {
3463 // Simple case: normal parameter, or a parameter pack that's
3464 // instantiated to a (still-dependent) parameter pack.
3465 ParmVarDecl *NewParam = NewProtoLoc.getParam(NewIdx++);
3466 Params.push_back(NewParam);
3467 Scope->InstantiatedLocal(OldParam, NewParam);
3469 // Parameter pack expansion: make the instantiation an argument pack.
3470 Scope->MakeInstantiatedLocalArgPack(OldParam);
3471 for (unsigned I = 0; I != *NumArgumentsInExpansion; ++I) {
3472 ParmVarDecl *NewParam = NewProtoLoc.getParam(NewIdx++);
3473 Params.push_back(NewParam);
3474 Scope->InstantiatedLocalPackArg(OldParam, NewParam);
3479 // The function type itself was not dependent and therefore no
3480 // substitution occurred. However, we still need to instantiate
3481 // the function parameters themselves.
3482 const FunctionProtoType *OldProto =
3483 cast<FunctionProtoType>(OldProtoLoc.getType());
3484 for (unsigned i = 0, i_end = OldProtoLoc.getNumParams(); i != i_end;
3486 ParmVarDecl *OldParam = OldProtoLoc.getParam(i);
3488 Params.push_back(SemaRef.BuildParmVarDeclForTypedef(
3489 D, D->getLocation(), OldProto->getParamType(i)));
3494 cast_or_null<ParmVarDecl>(VisitParmVarDecl(OldParam));
3497 Params.push_back(Parm);
3501 // If the type of this function, after ignoring parentheses, is not
3502 // *directly* a function type, then we're instantiating a function that
3503 // was declared via a typedef or with attributes, e.g.,
3505 // typedef int functype(int, int);
3507 // int __cdecl meth(int, int);
3509 // In this case, we'll just go instantiate the ParmVarDecls that we
3510 // synthesized in the method declaration.
3511 SmallVector<QualType, 4> ParamTypes;
3512 Sema::ExtParameterInfoBuilder ExtParamInfos;
3513 if (SemaRef.SubstParmTypes(D->getLocation(), D->parameters(), nullptr,
3514 TemplateArgs, ParamTypes, &Params,
3522 /// Introduce the instantiated function parameters into the local
3523 /// instantiation scope, and set the parameter names to those used
3524 /// in the template.
3525 static bool addInstantiatedParametersToScope(Sema &S, FunctionDecl *Function,
3526 const FunctionDecl *PatternDecl,
3527 LocalInstantiationScope &Scope,
3528 const MultiLevelTemplateArgumentList &TemplateArgs) {
3529 unsigned FParamIdx = 0;
3530 for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
3531 const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
3532 if (!PatternParam->isParameterPack()) {
3533 // Simple case: not a parameter pack.
3534 assert(FParamIdx < Function->getNumParams());
3535 ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
3536 FunctionParam->setDeclName(PatternParam->getDeclName());
3537 // If the parameter's type is not dependent, update it to match the type
3538 // in the pattern. They can differ in top-level cv-qualifiers, and we want
3539 // the pattern's type here. If the type is dependent, they can't differ,
3540 // per core issue 1668. Substitute into the type from the pattern, in case
3541 // it's instantiation-dependent.
3542 // FIXME: Updating the type to work around this is at best fragile.
3543 if (!PatternDecl->getType()->isDependentType()) {
3544 QualType T = S.SubstType(PatternParam->getType(), TemplateArgs,
3545 FunctionParam->getLocation(),
3546 FunctionParam->getDeclName());
3549 FunctionParam->setType(T);
3552 Scope.InstantiatedLocal(PatternParam, FunctionParam);
3557 // Expand the parameter pack.
3558 Scope.MakeInstantiatedLocalArgPack(PatternParam);
3559 Optional<unsigned> NumArgumentsInExpansion
3560 = S.getNumArgumentsInExpansion(PatternParam->getType(), TemplateArgs);
3561 assert(NumArgumentsInExpansion &&
3562 "should only be called when all template arguments are known");
3563 QualType PatternType =
3564 PatternParam->getType()->castAs<PackExpansionType>()->getPattern();
3565 for (unsigned Arg = 0; Arg < *NumArgumentsInExpansion; ++Arg) {
3566 ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
3567 FunctionParam->setDeclName(PatternParam->getDeclName());
3568 if (!PatternDecl->getType()->isDependentType()) {
3569 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, Arg);
3570 QualType T = S.SubstType(PatternType, TemplateArgs,
3571 FunctionParam->getLocation(),
3572 FunctionParam->getDeclName());
3575 FunctionParam->setType(T);
3578 Scope.InstantiatedLocalPackArg(PatternParam, FunctionParam);
3586 void Sema::InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
3587 FunctionDecl *Decl) {
3588 const FunctionProtoType *Proto = Decl->getType()->castAs<FunctionProtoType>();
3589 if (Proto->getExceptionSpecType() != EST_Uninstantiated)
3592 InstantiatingTemplate Inst(*this, PointOfInstantiation, Decl,
3593 InstantiatingTemplate::ExceptionSpecification());
3594 if (Inst.isInvalid()) {
3595 // We hit the instantiation depth limit. Clear the exception specification
3596 // so that our callers don't have to cope with EST_Uninstantiated.
3597 UpdateExceptionSpec(Decl, EST_None);
3600 if (Inst.isAlreadyInstantiating()) {
3601 // This exception specification indirectly depends on itself. Reject.
3602 // FIXME: Corresponding rule in the standard?
3603 Diag(PointOfInstantiation, diag::err_exception_spec_cycle) << Decl;
3604 UpdateExceptionSpec(Decl, EST_None);
3608 // Enter the scope of this instantiation. We don't use
3609 // PushDeclContext because we don't have a scope.
3610 Sema::ContextRAII savedContext(*this, Decl);
3611 LocalInstantiationScope Scope(*this);
3613 MultiLevelTemplateArgumentList TemplateArgs =
3614 getTemplateInstantiationArgs(Decl, nullptr, /*RelativeToPrimary*/true);
3616 FunctionDecl *Template = Proto->getExceptionSpecTemplate();
3617 if (addInstantiatedParametersToScope(*this, Decl, Template, Scope,
3619 UpdateExceptionSpec(Decl, EST_None);
3623 SubstExceptionSpec(Decl, Template->getType()->castAs<FunctionProtoType>(),
3627 /// \brief Initializes the common fields of an instantiation function
3628 /// declaration (New) from the corresponding fields of its template (Tmpl).
3630 /// \returns true if there was an error
3632 TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
3633 FunctionDecl *Tmpl) {
3634 if (Tmpl->isDeleted())
3635 New->setDeletedAsWritten();
3637 New->setImplicit(Tmpl->isImplicit());
3639 // Forward the mangling number from the template to the instantiated decl.
3640 SemaRef.Context.setManglingNumber(New,
3641 SemaRef.Context.getManglingNumber(Tmpl));
3643 // If we are performing substituting explicitly-specified template arguments
3644 // or deduced template arguments into a function template and we reach this
3645 // point, we are now past the point where SFINAE applies and have committed
3646 // to keeping the new function template specialization. We therefore
3647 // convert the active template instantiation for the function template
3648 // into a template instantiation for this specific function template
3649 // specialization, which is not a SFINAE context, so that we diagnose any
3650 // further errors in the declaration itself.
3651 typedef Sema::CodeSynthesisContext ActiveInstType;
3652 ActiveInstType &ActiveInst = SemaRef.CodeSynthesisContexts.back();
3653 if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
3654 ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
3655 if (FunctionTemplateDecl *FunTmpl
3656 = dyn_cast<FunctionTemplateDecl>(ActiveInst.Entity)) {
3657 assert(FunTmpl->getTemplatedDecl() == Tmpl &&
3658 "Deduction from the wrong function template?");
3660 ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
3661 ActiveInst.Entity = New;
3665 const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
3666 assert(Proto && "Function template without prototype?");
3668 if (Proto->hasExceptionSpec() || Proto->getNoReturnAttr()) {
3669 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
3671 // DR1330: In C++11, defer instantiation of a non-trivial
3672 // exception specification.
3673 // DR1484: Local classes and their members are instantiated along with the
3674 // containing function.
3675 if (SemaRef.getLangOpts().CPlusPlus11 &&
3676 EPI.ExceptionSpec.Type != EST_None &&
3677 EPI.ExceptionSpec.Type != EST_DynamicNone &&
3678 EPI.ExceptionSpec.Type != EST_BasicNoexcept &&
3679 !Tmpl->isLexicallyWithinFunctionOrMethod()) {
3680 FunctionDecl *ExceptionSpecTemplate = Tmpl;
3681 if (EPI.ExceptionSpec.Type == EST_Uninstantiated)
3682 ExceptionSpecTemplate = EPI.ExceptionSpec.SourceTemplate;
3683 ExceptionSpecificationType NewEST = EST_Uninstantiated;
3684 if (EPI.ExceptionSpec.Type == EST_Unevaluated)
3685 NewEST = EST_Unevaluated;
3687 // Mark the function has having an uninstantiated exception specification.
3688 const FunctionProtoType *NewProto
3689 = New->getType()->getAs<FunctionProtoType>();
3690 assert(NewProto && "Template instantiation without function prototype?");
3691 EPI = NewProto->getExtProtoInfo();
3692 EPI.ExceptionSpec.Type = NewEST;
3693 EPI.ExceptionSpec.SourceDecl = New;
3694 EPI.ExceptionSpec.SourceTemplate = ExceptionSpecTemplate;
3695 New->setType(SemaRef.Context.getFunctionType(
3696 NewProto->getReturnType(), NewProto->getParamTypes(), EPI));
3698 Sema::ContextRAII SwitchContext(SemaRef, New);
3699 SemaRef.SubstExceptionSpec(New, Proto, TemplateArgs);
3703 // Get the definition. Leaves the variable unchanged if undefined.
3704 const FunctionDecl *Definition = Tmpl;
3705 Tmpl->isDefined(Definition);
3707 SemaRef.InstantiateAttrs(TemplateArgs, Definition, New,
3708 LateAttrs, StartingScope);
3713 /// \brief Initializes common fields of an instantiated method
3714 /// declaration (New) from the corresponding fields of its template
3717 /// \returns true if there was an error
3719 TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
3720 CXXMethodDecl *Tmpl) {
3721 if (InitFunctionInstantiation(New, Tmpl))
3724 New->setAccess(Tmpl->getAccess());
3725 if (Tmpl->isVirtualAsWritten())
3726 New->setVirtualAsWritten(true);
3728 // FIXME: New needs a pointer to Tmpl
3732 /// Instantiate (or find existing instantiation of) a function template with a
3733 /// given set of template arguments.
3735 /// Usually this should not be used, and template argument deduction should be
3736 /// used in its place.
3738 Sema::InstantiateFunctionDeclaration(FunctionTemplateDecl *FTD,
3739 const TemplateArgumentList *Args,
3740 SourceLocation Loc) {
3741 FunctionDecl *FD = FTD->getTemplatedDecl();
3743 sema::TemplateDeductionInfo Info(Loc);
3744 InstantiatingTemplate Inst(
3745 *this, Loc, FTD, Args->asArray(),
3746 CodeSynthesisContext::ExplicitTemplateArgumentSubstitution, Info);
3747 if (Inst.isInvalid())
3750 ContextRAII SavedContext(*this, FD);
3751 MultiLevelTemplateArgumentList MArgs(*Args);
3753 return cast_or_null<FunctionDecl>(SubstDecl(FD, FD->getParent(), MArgs));
3756 /// In the MS ABI, we need to instantiate default arguments of dllexported
3757 /// default constructors along with the constructor definition. This allows IR
3758 /// gen to emit a constructor closure which calls the default constructor with
3759 /// its default arguments.
3760 static void InstantiateDefaultCtorDefaultArgs(Sema &S,
3761 CXXConstructorDecl *Ctor) {
3762 assert(S.Context.getTargetInfo().getCXXABI().isMicrosoft() &&
3763 Ctor->isDefaultConstructor());
3764 unsigned NumParams = Ctor->getNumParams();
3767 DLLExportAttr *Attr = Ctor->getAttr<DLLExportAttr>();
3770 for (unsigned I = 0; I != NumParams; ++I) {
3771 (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), Ctor,
3772 Ctor->getParamDecl(I));
3773 S.DiscardCleanupsInEvaluationContext();
3777 /// \brief Instantiate the definition of the given function from its
3780 /// \param PointOfInstantiation the point at which the instantiation was
3781 /// required. Note that this is not precisely a "point of instantiation"
3782 /// for the function, but it's close.
3784 /// \param Function the already-instantiated declaration of a
3785 /// function template specialization or member function of a class template
3788 /// \param Recursive if true, recursively instantiates any functions that
3789 /// are required by this instantiation.
3791 /// \param DefinitionRequired if true, then we are performing an explicit
3792 /// instantiation where the body of the function is required. Complain if
3793 /// there is no such body.
3794 void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
3795 FunctionDecl *Function,
3797 bool DefinitionRequired,
3799 if (Function->isInvalidDecl() || Function->isDefined() ||
3800 isa<CXXDeductionGuideDecl>(Function))
3803 // Never instantiate an explicit specialization except if it is a class scope
3804 // explicit specialization.
3805 TemplateSpecializationKind TSK = Function->getTemplateSpecializationKind();
3806 if (TSK == TSK_ExplicitSpecialization &&
3807 !Function->getClassScopeSpecializationPattern())
3810 // Find the function body that we'll be substituting.
3811 const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
3812 assert(PatternDecl && "instantiating a non-template");
3814 const FunctionDecl *PatternDef = PatternDecl->getDefinition();
3815 Stmt *Pattern = nullptr;
3817 Pattern = PatternDef->getBody(PatternDef);
3818 PatternDecl = PatternDef;
3819 if (PatternDef->willHaveBody())
3820 PatternDef = nullptr;
3823 // FIXME: We need to track the instantiation stack in order to know which
3824 // definitions should be visible within this instantiation.
3825 if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Function,
3826 Function->getInstantiatedFromMemberFunction(),
3827 PatternDecl, PatternDef, TSK,
3828 /*Complain*/DefinitionRequired)) {
3829 if (DefinitionRequired)
3830 Function->setInvalidDecl();
3831 else if (TSK == TSK_ExplicitInstantiationDefinition) {
3832 // Try again at the end of the translation unit (at which point a
3833 // definition will be required).
3835 Function->setInstantiationIsPending(true);
3836 PendingInstantiations.push_back(
3837 std::make_pair(Function, PointOfInstantiation));
3838 } else if (TSK == TSK_ImplicitInstantiation) {
3839 if (AtEndOfTU && !getDiagnostics().hasErrorOccurred() &&
3840 !getSourceManager().isInSystemHeader(PatternDecl->getLocStart())) {
3841 Diag(PointOfInstantiation, diag::warn_func_template_missing)
3843 Diag(PatternDecl->getLocation(), diag::note_forward_template_decl);
3844 if (getLangOpts().CPlusPlus11)
3845 Diag(PointOfInstantiation, diag::note_inst_declaration_hint)
3853 // Postpone late parsed template instantiations.
3854 if (PatternDecl->isLateTemplateParsed() &&
3855 !LateTemplateParser) {
3856 Function->setInstantiationIsPending(true);
3857 PendingInstantiations.push_back(
3858 std::make_pair(Function, PointOfInstantiation));
3862 // If we're performing recursive template instantiation, create our own
3863 // queue of pending implicit instantiations that we will instantiate later,
3864 // while we're still within our own instantiation context.
3865 // This has to happen before LateTemplateParser below is called, so that
3866 // it marks vtables used in late parsed templates as used.
3867 GlobalEagerInstantiationScope GlobalInstantiations(*this,
3868 /*Enabled=*/Recursive);
3869 LocalEagerInstantiationScope LocalInstantiations(*this);
3871 // Call the LateTemplateParser callback if there is a need to late parse
3872 // a templated function definition.
3873 if (!Pattern && PatternDecl->isLateTemplateParsed() &&
3874 LateTemplateParser) {
3875 // FIXME: Optimize to allow individual templates to be deserialized.
3876 if (PatternDecl->isFromASTFile())
3877 ExternalSource->ReadLateParsedTemplates(LateParsedTemplateMap);
3879 auto LPTIter = LateParsedTemplateMap.find(PatternDecl);
3880 assert(LPTIter != LateParsedTemplateMap.end() &&
3881 "missing LateParsedTemplate");
3882 LateTemplateParser(OpaqueParser, *LPTIter->second);
3883 Pattern = PatternDecl->getBody(PatternDecl);
3886 // Note, we should never try to instantiate a deleted function template.
3887 assert((Pattern || PatternDecl->isDefaulted() ||
3888 PatternDecl->hasSkippedBody()) &&
3889 "unexpected kind of function template definition");
3891 // C++1y [temp.explicit]p10:
3892 // Except for inline functions, declarations with types deduced from their
3893 // initializer or return value, and class template specializations, other
3894 // explicit instantiation declarations have the effect of suppressing the
3895 // implicit instantiation of the entity to which they refer.
3896 if (TSK == TSK_ExplicitInstantiationDeclaration &&
3897 !PatternDecl->isInlined() &&
3898 !PatternDecl->getReturnType()->getContainedAutoType())
3901 if (PatternDecl->isInlined()) {
3902 // Function, and all later redeclarations of it (from imported modules,
3903 // for instance), are now implicitly inline.
3904 for (auto *D = Function->getMostRecentDecl(); /**/;
3905 D = D->getPreviousDecl()) {
3906 D->setImplicitlyInline();
3912 InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
3913 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
3915 PrettyDeclStackTraceEntry CrashInfo(*this, Function, SourceLocation(),
3916 "instantiating function definition");
3918 // The instantiation is visible here, even if it was first declared in an
3919 // unimported module.
3920 Function->setVisibleDespiteOwningModule();
3922 // Copy the inner loc start from the pattern.
3923 Function->setInnerLocStart(PatternDecl->getInnerLocStart());
3925 EnterExpressionEvaluationContext EvalContext(
3926 *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
3928 // Introduce a new scope where local variable instantiations will be
3929 // recorded, unless we're actually a member function within a local
3930 // class, in which case we need to merge our results with the parent
3931 // scope (of the enclosing function).
3932 bool MergeWithParentScope = false;
3933 if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
3934 MergeWithParentScope = Rec->isLocalClass();
3936 LocalInstantiationScope Scope(*this, MergeWithParentScope);
3938 if (PatternDecl->isDefaulted())
3939 SetDeclDefaulted(Function, PatternDecl->getLocation());
3941 MultiLevelTemplateArgumentList TemplateArgs =
3942 getTemplateInstantiationArgs(Function, nullptr, false, PatternDecl);
3944 // Substitute into the qualifier; we can get a substitution failure here
3945 // through evil use of alias templates.
3946 // FIXME: Is CurContext correct for this? Should we go to the (instantiation
3947 // of the) lexical context of the pattern?
3948 SubstQualifier(*this, PatternDecl, Function, TemplateArgs);
3950 ActOnStartOfFunctionDef(nullptr, Function);
3952 // Enter the scope of this instantiation. We don't use
3953 // PushDeclContext because we don't have a scope.
3954 Sema::ContextRAII savedContext(*this, Function);
3956 if (addInstantiatedParametersToScope(*this, Function, PatternDecl, Scope,
3960 if (PatternDecl->hasSkippedBody()) {
3961 ActOnSkippedFunctionBody(Function);
3963 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Function)) {
3964 // If this is a constructor, instantiate the member initializers.
3965 InstantiateMemInitializers(Ctor, cast<CXXConstructorDecl>(PatternDecl),
3968 // If this is an MS ABI dllexport default constructor, instantiate any
3969 // default arguments.
3970 if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
3971 Ctor->isDefaultConstructor()) {
3972 InstantiateDefaultCtorDefaultArgs(*this, Ctor);
3976 // Instantiate the function body.
3977 StmtResult Body = SubstStmt(Pattern, TemplateArgs);
3979 if (Body.isInvalid())
3980 Function->setInvalidDecl();
3982 // FIXME: finishing the function body while in an expression evaluation
3983 // context seems wrong. Investigate more.
3984 ActOnFinishFunctionBody(Function, Body.get(),
3985 /*IsInstantiation=*/true);
3988 PerformDependentDiagnostics(PatternDecl, TemplateArgs);
3990 if (auto *Listener = getASTMutationListener())
3991 Listener->FunctionDefinitionInstantiated(Function);
3996 DeclGroupRef DG(Function);
3997 Consumer.HandleTopLevelDecl(DG);
3999 // This class may have local implicit instantiations that need to be
4000 // instantiation within this scope.
4001 LocalInstantiations.perform();
4003 GlobalInstantiations.perform();
4006 VarTemplateSpecializationDecl *Sema::BuildVarTemplateInstantiation(
4007 VarTemplateDecl *VarTemplate, VarDecl *FromVar,
4008 const TemplateArgumentList &TemplateArgList,
4009 const TemplateArgumentListInfo &TemplateArgsInfo,
4010 SmallVectorImpl<TemplateArgument> &Converted,
4011 SourceLocation PointOfInstantiation, void *InsertPos,
4012 LateInstantiatedAttrVec *LateAttrs,
4013 LocalInstantiationScope *StartingScope) {
4014 if (FromVar->isInvalidDecl())
4017 InstantiatingTemplate Inst(*this, PointOfInstantiation, FromVar);
4018 if (Inst.isInvalid())
4021 MultiLevelTemplateArgumentList TemplateArgLists;
4022 TemplateArgLists.addOuterTemplateArguments(&TemplateArgList);
4024 // Instantiate the first declaration of the variable template: for a partial
4025 // specialization of a static data member template, the first declaration may
4026 // or may not be the declaration in the class; if it's in the class, we want
4027 // to instantiate a member in the class (a declaration), and if it's outside,
4028 // we want to instantiate a definition.
4030 // If we're instantiating an explicitly-specialized member template or member
4031 // partial specialization, don't do this. The member specialization completely
4032 // replaces the original declaration in this case.
4033 bool IsMemberSpec = false;
4034 if (VarTemplatePartialSpecializationDecl *PartialSpec =
4035 dyn_cast<VarTemplatePartialSpecializationDecl>(FromVar))
4036 IsMemberSpec = PartialSpec->isMemberSpecialization();
4037 else if (VarTemplateDecl *FromTemplate = FromVar->getDescribedVarTemplate())
4038 IsMemberSpec = FromTemplate->isMemberSpecialization();
4040 FromVar = FromVar->getFirstDecl();
4042 MultiLevelTemplateArgumentList MultiLevelList(TemplateArgList);
4043 TemplateDeclInstantiator Instantiator(*this, FromVar->getDeclContext(),
4046 // TODO: Set LateAttrs and StartingScope ...
4048 return cast_or_null<VarTemplateSpecializationDecl>(
4049 Instantiator.VisitVarTemplateSpecializationDecl(
4050 VarTemplate, FromVar, InsertPos, TemplateArgsInfo, Converted));
4053 /// \brief Instantiates a variable template specialization by completing it
4054 /// with appropriate type information and initializer.
4055 VarTemplateSpecializationDecl *Sema::CompleteVarTemplateSpecializationDecl(
4056 VarTemplateSpecializationDecl *VarSpec, VarDecl *PatternDecl,
4057 const MultiLevelTemplateArgumentList &TemplateArgs) {
4058 assert(PatternDecl->isThisDeclarationADefinition() &&
4059 "don't have a definition to instantiate from");
4061 // Do substitution on the type of the declaration
4062 TypeSourceInfo *DI =
4063 SubstType(PatternDecl->getTypeSourceInfo(), TemplateArgs,
4064 PatternDecl->getTypeSpecStartLoc(), PatternDecl->getDeclName());
4068 // Update the type of this variable template specialization.
4069 VarSpec->setType(DI->getType());
4071 // Convert the declaration into a definition now.
4072 VarSpec->setCompleteDefinition();
4074 // Instantiate the initializer.
4075 InstantiateVariableInitializer(VarSpec, PatternDecl, TemplateArgs);
4080 /// BuildVariableInstantiation - Used after a new variable has been created.
4081 /// Sets basic variable data and decides whether to postpone the
4082 /// variable instantiation.
4083 void Sema::BuildVariableInstantiation(
4084 VarDecl *NewVar, VarDecl *OldVar,
4085 const MultiLevelTemplateArgumentList &TemplateArgs,
4086 LateInstantiatedAttrVec *LateAttrs, DeclContext *Owner,
4087 LocalInstantiationScope *StartingScope,
4088 bool InstantiatingVarTemplate) {
4090 // If we are instantiating a local extern declaration, the
4091 // instantiation belongs lexically to the containing function.
4092 // If we are instantiating a static data member defined
4093 // out-of-line, the instantiation will have the same lexical
4094 // context (which will be a namespace scope) as the template.
4095 if (OldVar->isLocalExternDecl()) {
4096 NewVar->setLocalExternDecl();
4097 NewVar->setLexicalDeclContext(Owner);
4098 } else if (OldVar->isOutOfLine())
4099 NewVar->setLexicalDeclContext(OldVar->getLexicalDeclContext());
4100 NewVar->setTSCSpec(OldVar->getTSCSpec());
4101 NewVar->setInitStyle(OldVar->getInitStyle());
4102 NewVar->setCXXForRangeDecl(OldVar->isCXXForRangeDecl());
4103 NewVar->setConstexpr(OldVar->isConstexpr());
4104 NewVar->setInitCapture(OldVar->isInitCapture());
4105 NewVar->setPreviousDeclInSameBlockScope(
4106 OldVar->isPreviousDeclInSameBlockScope());
4107 NewVar->setAccess(OldVar->getAccess());
4109 if (!OldVar->isStaticDataMember()) {
4110 if (OldVar->isUsed(false))
4111 NewVar->setIsUsed();
4112 NewVar->setReferenced(OldVar->isReferenced());
4115 InstantiateAttrs(TemplateArgs, OldVar, NewVar, LateAttrs, StartingScope);
4117 LookupResult Previous(
4118 *this, NewVar->getDeclName(), NewVar->getLocation(),
4119 NewVar->isLocalExternDecl() ? Sema::LookupRedeclarationWithLinkage
4120 : Sema::LookupOrdinaryName,
4121 NewVar->isLocalExternDecl() ? Sema::ForExternalRedeclaration
4122 : forRedeclarationInCurContext());
4124 if (NewVar->isLocalExternDecl() && OldVar->getPreviousDecl() &&
4125 (!OldVar->getPreviousDecl()->getDeclContext()->isDependentContext() ||
4126 OldVar->getPreviousDecl()->getDeclContext()==OldVar->getDeclContext())) {
4127 // We have a previous declaration. Use that one, so we merge with the
4129 if (NamedDecl *NewPrev = FindInstantiatedDecl(
4130 NewVar->getLocation(), OldVar->getPreviousDecl(), TemplateArgs))
4131 Previous.addDecl(NewPrev);
4132 } else if (!isa<VarTemplateSpecializationDecl>(NewVar) &&
4133 OldVar->hasLinkage())
4134 LookupQualifiedName(Previous, NewVar->getDeclContext(), false);
4135 CheckVariableDeclaration(NewVar, Previous);
4137 if (!InstantiatingVarTemplate) {
4138 NewVar->getLexicalDeclContext()->addHiddenDecl(NewVar);
4139 if (!NewVar->isLocalExternDecl() || !NewVar->getPreviousDecl())
4140 NewVar->getDeclContext()->makeDeclVisibleInContext(NewVar);
4143 if (!OldVar->isOutOfLine()) {
4144 if (NewVar->getDeclContext()->isFunctionOrMethod())
4145 CurrentInstantiationScope->InstantiatedLocal(OldVar, NewVar);
4148 // Link instantiations of static data members back to the template from
4149 // which they were instantiated.
4150 if (NewVar->isStaticDataMember() && !InstantiatingVarTemplate)
4151 NewVar->setInstantiationOfStaticDataMember(OldVar,
4152 TSK_ImplicitInstantiation);
4154 // Forward the mangling number from the template to the instantiated decl.
4155 Context.setManglingNumber(NewVar, Context.getManglingNumber(OldVar));
4156 Context.setStaticLocalNumber(NewVar, Context.getStaticLocalNumber(OldVar));
4158 // Delay instantiation of the initializer for variable templates or inline
4159 // static data members until a definition of the variable is needed. We need
4160 // it right away if the type contains 'auto'.
4161 if ((!isa<VarTemplateSpecializationDecl>(NewVar) &&
4162 !InstantiatingVarTemplate &&
4163 !(OldVar->isInline() && OldVar->isThisDeclarationADefinition())) ||
4164 NewVar->getType()->isUndeducedType())
4165 InstantiateVariableInitializer(NewVar, OldVar, TemplateArgs);
4167 // Diagnose unused local variables with dependent types, where the diagnostic
4168 // will have been deferred.
4169 if (!NewVar->isInvalidDecl() &&
4170 NewVar->getDeclContext()->isFunctionOrMethod() &&
4171 OldVar->getType()->isDependentType())
4172 DiagnoseUnusedDecl(NewVar);
4175 /// \brief Instantiate the initializer of a variable.
4176 void Sema::InstantiateVariableInitializer(
4177 VarDecl *Var, VarDecl *OldVar,
4178 const MultiLevelTemplateArgumentList &TemplateArgs) {
4179 if (ASTMutationListener *L = getASTContext().getASTMutationListener())
4180 L->VariableDefinitionInstantiated(Var);
4182 // We propagate the 'inline' flag with the initializer, because it
4183 // would otherwise imply that the variable is a definition for a
4184 // non-static data member.
4185 if (OldVar->isInlineSpecified())
4186 Var->setInlineSpecified();
4187 else if (OldVar->isInline())
4188 Var->setImplicitlyInline();
4190 if (OldVar->getInit()) {
4191 EnterExpressionEvaluationContext Evaluated(
4192 *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated, Var);
4194 // Instantiate the initializer.
4198 ContextRAII SwitchContext(*this, Var->getDeclContext());
4199 Init = SubstInitializer(OldVar->getInit(), TemplateArgs,
4200 OldVar->getInitStyle() == VarDecl::CallInit);
4203 if (!Init.isInvalid()) {
4204 Expr *InitExpr = Init.get();
4206 if (Var->hasAttr<DLLImportAttr>() &&
4208 !InitExpr->isConstantInitializer(getASTContext(), false))) {
4209 // Do not dynamically initialize dllimport variables.
4210 } else if (InitExpr) {
4211 bool DirectInit = OldVar->isDirectInit();
4212 AddInitializerToDecl(Var, InitExpr, DirectInit);
4214 ActOnUninitializedDecl(Var);
4216 // FIXME: Not too happy about invalidating the declaration
4217 // because of a bogus initializer.
4218 Var->setInvalidDecl();
4221 if (Var->isStaticDataMember()) {
4222 if (!Var->isOutOfLine())
4225 // If the declaration inside the class had an initializer, don't add
4226 // another one to the out-of-line definition.
4227 if (OldVar->getFirstDecl()->hasInit())
4231 // We'll add an initializer to a for-range declaration later.
4232 if (Var->isCXXForRangeDecl())
4235 ActOnUninitializedDecl(Var);
4239 /// \brief Instantiate the definition of the given variable from its
4242 /// \param PointOfInstantiation the point at which the instantiation was
4243 /// required. Note that this is not precisely a "point of instantiation"
4244 /// for the variable, but it's close.
4246 /// \param Var the already-instantiated declaration of a templated variable.
4248 /// \param Recursive if true, recursively instantiates any functions that
4249 /// are required by this instantiation.
4251 /// \param DefinitionRequired if true, then we are performing an explicit
4252 /// instantiation where a definition of the variable is required. Complain
4253 /// if there is no such definition.
4254 void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
4255 VarDecl *Var, bool Recursive,
4256 bool DefinitionRequired, bool AtEndOfTU) {
4257 if (Var->isInvalidDecl())
4260 VarTemplateSpecializationDecl *VarSpec =
4261 dyn_cast<VarTemplateSpecializationDecl>(Var);
4262 VarDecl *PatternDecl = nullptr, *Def = nullptr;
4263 MultiLevelTemplateArgumentList TemplateArgs =
4264 getTemplateInstantiationArgs(Var);
4267 // If this is a variable template specialization, make sure that it is
4268 // non-dependent, then find its instantiation pattern.
4269 bool InstantiationDependent = false;
4270 assert(!TemplateSpecializationType::anyDependentTemplateArguments(
4271 VarSpec->getTemplateArgsInfo(), InstantiationDependent) &&
4272 "Only instantiate variable template specializations that are "
4273 "not type-dependent");
4274 (void)InstantiationDependent;
4276 // Find the variable initialization that we'll be substituting. If the
4277 // pattern was instantiated from a member template, look back further to
4278 // find the real pattern.
4279 assert(VarSpec->getSpecializedTemplate() &&
4280 "Specialization without specialized template?");
4281 llvm::PointerUnion<VarTemplateDecl *,
4282 VarTemplatePartialSpecializationDecl *> PatternPtr =
4283 VarSpec->getSpecializedTemplateOrPartial();
4284 if (PatternPtr.is<VarTemplatePartialSpecializationDecl *>()) {
4285 VarTemplatePartialSpecializationDecl *Tmpl =
4286 PatternPtr.get<VarTemplatePartialSpecializationDecl *>();
4287 while (VarTemplatePartialSpecializationDecl *From =
4288 Tmpl->getInstantiatedFromMember()) {
4289 if (Tmpl->isMemberSpecialization())
4296 VarTemplateDecl *Tmpl = PatternPtr.get<VarTemplateDecl *>();
4297 while (VarTemplateDecl *From =
4298 Tmpl->getInstantiatedFromMemberTemplate()) {
4299 if (Tmpl->isMemberSpecialization())
4304 PatternDecl = Tmpl->getTemplatedDecl();
4307 // If this is a static data member template, there might be an
4308 // uninstantiated initializer on the declaration. If so, instantiate
4311 // FIXME: This largely duplicates what we would do below. The difference
4312 // is that along this path we may instantiate an initializer from an
4313 // in-class declaration of the template and instantiate the definition
4314 // from a separate out-of-class definition.
4315 if (PatternDecl->isStaticDataMember() &&
4316 (PatternDecl = PatternDecl->getFirstDecl())->hasInit() &&
4318 // FIXME: Factor out the duplicated instantiation context setup/tear down
4320 InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
4321 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
4323 PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
4324 "instantiating variable initializer");
4326 // The instantiation is visible here, even if it was first declared in an
4327 // unimported module.
4328 Var->setVisibleDespiteOwningModule();
4330 // If we're performing recursive template instantiation, create our own
4331 // queue of pending implicit instantiations that we will instantiate
4332 // later, while we're still within our own instantiation context.
4333 GlobalEagerInstantiationScope GlobalInstantiations(*this,
4334 /*Enabled=*/Recursive);
4335 LocalInstantiationScope Local(*this);
4336 LocalEagerInstantiationScope LocalInstantiations(*this);
4338 // Enter the scope of this instantiation. We don't use
4339 // PushDeclContext because we don't have a scope.
4340 ContextRAII PreviousContext(*this, Var->getDeclContext());
4341 InstantiateVariableInitializer(Var, PatternDecl, TemplateArgs);
4342 PreviousContext.pop();
4344 // This variable may have local implicit instantiations that need to be
4345 // instantiated within this scope.
4346 LocalInstantiations.perform();
4348 GlobalInstantiations.perform();
4351 // Find actual definition
4352 Def = PatternDecl->getDefinition(getASTContext());
4354 // If this is a static data member, find its out-of-line definition.
4355 assert(Var->isStaticDataMember() && "not a static data member?");
4356 PatternDecl = Var->getInstantiatedFromStaticDataMember();
4358 assert(PatternDecl && "data member was not instantiated from a template?");
4359 assert(PatternDecl->isStaticDataMember() && "not a static data member?");
4360 Def = PatternDecl->getDefinition();
4363 TemplateSpecializationKind TSK = Var->getTemplateSpecializationKind();
4365 // If we don't have a definition of the variable template, we won't perform
4366 // any instantiation. Rather, we rely on the user to instantiate this
4367 // definition (or provide a specialization for it) in another translation
4369 if (!Def && !DefinitionRequired) {
4370 if (TSK == TSK_ExplicitInstantiationDefinition) {
4371 PendingInstantiations.push_back(
4372 std::make_pair(Var, PointOfInstantiation));
4373 } else if (TSK == TSK_ImplicitInstantiation) {
4374 // Warn about missing definition at the end of translation unit.
4375 if (AtEndOfTU && !getDiagnostics().hasErrorOccurred() &&
4376 !getSourceManager().isInSystemHeader(PatternDecl->getLocStart())) {
4377 Diag(PointOfInstantiation, diag::warn_var_template_missing)
4379 Diag(PatternDecl->getLocation(), diag::note_forward_template_decl);
4380 if (getLangOpts().CPlusPlus11)
4381 Diag(PointOfInstantiation, diag::note_inst_declaration_hint) << Var;
4388 // FIXME: We need to track the instantiation stack in order to know which
4389 // definitions should be visible within this instantiation.
4390 // FIXME: Produce diagnostics when Var->getInstantiatedFromStaticDataMember().
4391 if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Var,
4392 /*InstantiatedFromMember*/false,
4393 PatternDecl, Def, TSK,
4394 /*Complain*/DefinitionRequired))
4398 // Never instantiate an explicit specialization.
4399 if (TSK == TSK_ExplicitSpecialization)
4402 // C++11 [temp.explicit]p10:
4403 // Except for inline functions, const variables of literal types, variables
4404 // of reference types, [...] explicit instantiation declarations
4405 // have the effect of suppressing the implicit instantiation of the entity
4406 // to which they refer.
4407 if (TSK == TSK_ExplicitInstantiationDeclaration &&
4408 !Var->isUsableInConstantExpressions(getASTContext()))
4411 // Make sure to pass the instantiated variable to the consumer at the end.
4412 struct PassToConsumerRAII {
4413 ASTConsumer &Consumer;
4416 PassToConsumerRAII(ASTConsumer &Consumer, VarDecl *Var)
4417 : Consumer(Consumer), Var(Var) { }
4419 ~PassToConsumerRAII() {
4420 Consumer.HandleCXXStaticMemberVarInstantiation(Var);
4422 } PassToConsumerRAII(Consumer, Var);
4424 // If we already have a definition, we're done.
4425 if (VarDecl *Def = Var->getDefinition()) {
4426 // We may be explicitly instantiating something we've already implicitly
4428 Def->setTemplateSpecializationKind(Var->getTemplateSpecializationKind(),
4429 PointOfInstantiation);
4433 InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
4434 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
4436 PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
4437 "instantiating variable definition");
4439 // If we're performing recursive template instantiation, create our own
4440 // queue of pending implicit instantiations that we will instantiate later,
4441 // while we're still within our own instantiation context.
4442 GlobalEagerInstantiationScope GlobalInstantiations(*this,
4443 /*Enabled=*/Recursive);
4445 // Enter the scope of this instantiation. We don't use
4446 // PushDeclContext because we don't have a scope.
4447 ContextRAII PreviousContext(*this, Var->getDeclContext());
4448 LocalInstantiationScope Local(*this);
4450 LocalEagerInstantiationScope LocalInstantiations(*this);
4452 VarDecl *OldVar = Var;
4453 if (Def->isStaticDataMember() && !Def->isOutOfLine()) {
4454 // We're instantiating an inline static data member whose definition was
4455 // provided inside the class.
4456 InstantiateVariableInitializer(Var, Def, TemplateArgs);
4457 } else if (!VarSpec) {
4458 Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
4460 } else if (Var->isStaticDataMember() &&
4461 Var->getLexicalDeclContext()->isRecord()) {
4462 // We need to instantiate the definition of a static data member template,
4463 // and all we have is the in-class declaration of it. Instantiate a separate
4464 // declaration of the definition.
4465 TemplateDeclInstantiator Instantiator(*this, Var->getDeclContext(),
4467 Var = cast_or_null<VarDecl>(Instantiator.VisitVarTemplateSpecializationDecl(
4468 VarSpec->getSpecializedTemplate(), Def, nullptr,
4469 VarSpec->getTemplateArgsInfo(), VarSpec->getTemplateArgs().asArray()));
4471 llvm::PointerUnion<VarTemplateDecl *,
4472 VarTemplatePartialSpecializationDecl *> PatternPtr =
4473 VarSpec->getSpecializedTemplateOrPartial();
4474 if (VarTemplatePartialSpecializationDecl *Partial =
4475 PatternPtr.dyn_cast<VarTemplatePartialSpecializationDecl *>())
4476 cast<VarTemplateSpecializationDecl>(Var)->setInstantiationOf(
4477 Partial, &VarSpec->getTemplateInstantiationArgs());
4479 // Merge the definition with the declaration.
4480 LookupResult R(*this, Var->getDeclName(), Var->getLocation(),
4481 LookupOrdinaryName, forRedeclarationInCurContext());
4483 MergeVarDecl(Var, R);
4485 // Attach the initializer.
4486 InstantiateVariableInitializer(Var, Def, TemplateArgs);
4489 // Complete the existing variable's definition with an appropriately
4490 // substituted type and initializer.
4491 Var = CompleteVarTemplateSpecializationDecl(VarSpec, Def, TemplateArgs);
4493 PreviousContext.pop();
4496 PassToConsumerRAII.Var = Var;
4497 Var->setTemplateSpecializationKind(OldVar->getTemplateSpecializationKind(),
4498 OldVar->getPointOfInstantiation());
4501 // This variable may have local implicit instantiations that need to be
4502 // instantiated within this scope.
4503 LocalInstantiations.perform();
4505 GlobalInstantiations.perform();
4509 Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
4510 const CXXConstructorDecl *Tmpl,
4511 const MultiLevelTemplateArgumentList &TemplateArgs) {
4513 SmallVector<CXXCtorInitializer*, 4> NewInits;
4514 bool AnyErrors = Tmpl->isInvalidDecl();
4516 // Instantiate all the initializers.
4517 for (const auto *Init : Tmpl->inits()) {
4518 // Only instantiate written initializers, let Sema re-construct implicit
4520 if (!Init->isWritten())
4523 SourceLocation EllipsisLoc;
4525 if (Init->isPackExpansion()) {
4526 // This is a pack expansion. We should expand it now.
4527 TypeLoc BaseTL = Init->getTypeSourceInfo()->getTypeLoc();
4528 SmallVector<UnexpandedParameterPack, 4> Unexpanded;
4529 collectUnexpandedParameterPacks(BaseTL, Unexpanded);
4530 collectUnexpandedParameterPacks(Init->getInit(), Unexpanded);
4531 bool ShouldExpand = false;
4532 bool RetainExpansion = false;
4533 Optional<unsigned> NumExpansions;
4534 if (CheckParameterPacksForExpansion(Init->getEllipsisLoc(),
4535 BaseTL.getSourceRange(),
4537 TemplateArgs, ShouldExpand,
4541 New->setInvalidDecl();
4544 assert(ShouldExpand && "Partial instantiation of base initializer?");
4546 // Loop over all of the arguments in the argument pack(s),
4547 for (unsigned I = 0; I != *NumExpansions; ++I) {
4548 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, I);
4550 // Instantiate the initializer.
4551 ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs,
4552 /*CXXDirectInit=*/true);
4553 if (TempInit.isInvalid()) {
4558 // Instantiate the base type.
4559 TypeSourceInfo *BaseTInfo = SubstType(Init->getTypeSourceInfo(),
4561 Init->getSourceLocation(),
4562 New->getDeclName());
4568 // Build the initializer.
4569 MemInitResult NewInit = BuildBaseInitializer(BaseTInfo->getType(),
4570 BaseTInfo, TempInit.get(),
4573 if (NewInit.isInvalid()) {
4578 NewInits.push_back(NewInit.get());
4584 // Instantiate the initializer.
4585 ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs,
4586 /*CXXDirectInit=*/true);
4587 if (TempInit.isInvalid()) {
4592 MemInitResult NewInit;
4593 if (Init->isDelegatingInitializer() || Init->isBaseInitializer()) {
4594 TypeSourceInfo *TInfo = SubstType(Init->getTypeSourceInfo(),
4596 Init->getSourceLocation(),
4597 New->getDeclName());
4600 New->setInvalidDecl();
4604 if (Init->isBaseInitializer())
4605 NewInit = BuildBaseInitializer(TInfo->getType(), TInfo, TempInit.get(),
4606 New->getParent(), EllipsisLoc);
4608 NewInit = BuildDelegatingInitializer(TInfo, TempInit.get(),
4609 cast<CXXRecordDecl>(CurContext->getParent()));
4610 } else if (Init->isMemberInitializer()) {
4611 FieldDecl *Member = cast_or_null<FieldDecl>(FindInstantiatedDecl(
4612 Init->getMemberLocation(),
4617 New->setInvalidDecl();
4621 NewInit = BuildMemberInitializer(Member, TempInit.get(),
4622 Init->getSourceLocation());
4623 } else if (Init->isIndirectMemberInitializer()) {
4624 IndirectFieldDecl *IndirectMember =
4625 cast_or_null<IndirectFieldDecl>(FindInstantiatedDecl(
4626 Init->getMemberLocation(),
4627 Init->getIndirectMember(), TemplateArgs));
4629 if (!IndirectMember) {
4631 New->setInvalidDecl();
4635 NewInit = BuildMemberInitializer(IndirectMember, TempInit.get(),
4636 Init->getSourceLocation());
4639 if (NewInit.isInvalid()) {
4641 New->setInvalidDecl();
4643 NewInits.push_back(NewInit.get());
4647 // Assign all the initializers to the new constructor.
4648 ActOnMemInitializers(New,
4649 /*FIXME: ColonLoc */
4655 // TODO: this could be templated if the various decl types used the
4656 // same method name.
4657 static bool isInstantiationOf(ClassTemplateDecl *Pattern,
4658 ClassTemplateDecl *Instance) {
4659 Pattern = Pattern->getCanonicalDecl();
4662 Instance = Instance->getCanonicalDecl();
4663 if (Pattern == Instance) return true;
4664 Instance = Instance->getInstantiatedFromMemberTemplate();
4670 static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
4671 FunctionTemplateDecl *Instance) {
4672 Pattern = Pattern->getCanonicalDecl();
4675 Instance = Instance->getCanonicalDecl();
4676 if (Pattern == Instance) return true;
4677 Instance = Instance->getInstantiatedFromMemberTemplate();
4684 isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
4685 ClassTemplatePartialSpecializationDecl *Instance) {
4687 = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
4689 Instance = cast<ClassTemplatePartialSpecializationDecl>(
4690 Instance->getCanonicalDecl());
4691 if (Pattern == Instance)
4693 Instance = Instance->getInstantiatedFromMember();
4699 static bool isInstantiationOf(CXXRecordDecl *Pattern,
4700 CXXRecordDecl *Instance) {
4701 Pattern = Pattern->getCanonicalDecl();
4704 Instance = Instance->getCanonicalDecl();
4705 if (Pattern == Instance) return true;
4706 Instance = Instance->getInstantiatedFromMemberClass();
4712 static bool isInstantiationOf(FunctionDecl *Pattern,
4713 FunctionDecl *Instance) {
4714 Pattern = Pattern->getCanonicalDecl();
4717 Instance = Instance->getCanonicalDecl();
4718 if (Pattern == Instance) return true;
4719 Instance = Instance->getInstantiatedFromMemberFunction();
4725 static bool isInstantiationOf(EnumDecl *Pattern,
4726 EnumDecl *Instance) {
4727 Pattern = Pattern->getCanonicalDecl();
4730 Instance = Instance->getCanonicalDecl();
4731 if (Pattern == Instance) return true;
4732 Instance = Instance->getInstantiatedFromMemberEnum();
4738 static bool isInstantiationOf(UsingShadowDecl *Pattern,
4739 UsingShadowDecl *Instance,
4741 return declaresSameEntity(C.getInstantiatedFromUsingShadowDecl(Instance),
4745 static bool isInstantiationOf(UsingDecl *Pattern, UsingDecl *Instance,
4747 return declaresSameEntity(C.getInstantiatedFromUsingDecl(Instance), Pattern);
4750 template<typename T>
4751 static bool isInstantiationOfUnresolvedUsingDecl(T *Pattern, Decl *Other,
4753 // An unresolved using declaration can instantiate to an unresolved using
4754 // declaration, or to a using declaration or a using declaration pack.
4756 // Multiple declarations can claim to be instantiated from an unresolved
4757 // using declaration if it's a pack expansion. We want the UsingPackDecl
4758 // in that case, not the individual UsingDecls within the pack.
4759 bool OtherIsPackExpansion;
4760 NamedDecl *OtherFrom;
4761 if (auto *OtherUUD = dyn_cast<T>(Other)) {
4762 OtherIsPackExpansion = OtherUUD->isPackExpansion();
4763 OtherFrom = Ctx.getInstantiatedFromUsingDecl(OtherUUD);
4764 } else if (auto *OtherUPD = dyn_cast<UsingPackDecl>(Other)) {
4765 OtherIsPackExpansion = true;
4766 OtherFrom = OtherUPD->getInstantiatedFromUsingDecl();
4767 } else if (auto *OtherUD = dyn_cast<UsingDecl>(Other)) {
4768 OtherIsPackExpansion = false;
4769 OtherFrom = Ctx.getInstantiatedFromUsingDecl(OtherUD);
4773 return Pattern->isPackExpansion() == OtherIsPackExpansion &&
4774 declaresSameEntity(OtherFrom, Pattern);
4777 static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
4778 VarDecl *Instance) {
4779 assert(Instance->isStaticDataMember());
4781 Pattern = Pattern->getCanonicalDecl();
4784 Instance = Instance->getCanonicalDecl();
4785 if (Pattern == Instance) return true;
4786 Instance = Instance->getInstantiatedFromStaticDataMember();
4792 // Other is the prospective instantiation
4793 // D is the prospective pattern
4794 static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
4795 if (auto *UUD = dyn_cast<UnresolvedUsingTypenameDecl>(D))
4796 return isInstantiationOfUnresolvedUsingDecl(UUD, Other, Ctx);
4798 if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(D))
4799 return isInstantiationOfUnresolvedUsingDecl(UUD, Other, Ctx);
4801 if (D->getKind() != Other->getKind())
4804 if (auto *Record = dyn_cast<CXXRecordDecl>(Other))
4805 return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
4807 if (auto *Function = dyn_cast<FunctionDecl>(Other))
4808 return isInstantiationOf(cast<FunctionDecl>(D), Function);
4810 if (auto *Enum = dyn_cast<EnumDecl>(Other))
4811 return isInstantiationOf(cast<EnumDecl>(D), Enum);
4813 if (auto *Var = dyn_cast<VarDecl>(Other))
4814 if (Var->isStaticDataMember())
4815 return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
4817 if (auto *Temp = dyn_cast<ClassTemplateDecl>(Other))
4818 return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
4820 if (auto *Temp = dyn_cast<FunctionTemplateDecl>(Other))
4821 return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
4823 if (auto *PartialSpec =
4824 dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
4825 return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
4828 if (auto *Field = dyn_cast<FieldDecl>(Other)) {
4829 if (!Field->getDeclName()) {
4830 // This is an unnamed field.
4831 return declaresSameEntity(Ctx.getInstantiatedFromUnnamedFieldDecl(Field),
4832 cast<FieldDecl>(D));
4836 if (auto *Using = dyn_cast<UsingDecl>(Other))
4837 return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
4839 if (auto *Shadow = dyn_cast<UsingShadowDecl>(Other))
4840 return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
4842 return D->getDeclName() &&
4843 D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
4846 template<typename ForwardIterator>
4847 static NamedDecl *findInstantiationOf(ASTContext &Ctx,
4849 ForwardIterator first,
4850 ForwardIterator last) {
4851 for (; first != last; ++first)
4852 if (isInstantiationOf(Ctx, D, *first))
4853 return cast<NamedDecl>(*first);
4858 /// \brief Finds the instantiation of the given declaration context
4859 /// within the current instantiation.
4861 /// \returns NULL if there was an error
4862 DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
4863 const MultiLevelTemplateArgumentList &TemplateArgs) {
4864 if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
4865 Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs, true);
4866 return cast_or_null<DeclContext>(ID);
4870 /// \brief Find the instantiation of the given declaration within the
4871 /// current instantiation.
4873 /// This routine is intended to be used when \p D is a declaration
4874 /// referenced from within a template, that needs to mapped into the
4875 /// corresponding declaration within an instantiation. For example,
4879 /// template<typename T>
4882 /// KnownValue = sizeof(T)
4885 /// bool getKind() const { return KnownValue; }
4888 /// template struct X<int>;
4891 /// In the instantiation of <tt>X<int>::getKind()</tt>, we need to map the
4892 /// \p EnumConstantDecl for \p KnownValue (which refers to
4893 /// <tt>X<T>::<Kind>::KnownValue</tt>) to its instantiation
4894 /// (<tt>X<int>::<Kind>::KnownValue</tt>). \p FindInstantiatedDecl performs
4895 /// this mapping from within the instantiation of <tt>X<int></tt>.
4896 NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
4897 const MultiLevelTemplateArgumentList &TemplateArgs,
4898 bool FindingInstantiatedContext) {
4899 DeclContext *ParentDC = D->getDeclContext();
4900 // FIXME: Parmeters of pointer to functions (y below) that are themselves
4901 // parameters (p below) can have their ParentDC set to the translation-unit
4902 // - thus we can not consistently check if the ParentDC of such a parameter
4903 // is Dependent or/and a FunctionOrMethod.
4904 // For e.g. this code, during Template argument deduction tries to
4905 // find an instantiated decl for (T y) when the ParentDC for y is
4906 // the translation unit.
4907 // e.g. template <class T> void Foo(auto (*p)(T y) -> decltype(y())) {}
4908 // float baz(float(*)()) { return 0.0; }
4910 // The better fix here is perhaps to ensure that a ParmVarDecl, by the time
4911 // it gets here, always has a FunctionOrMethod as its ParentDC??
4913 // - as long as we have a ParmVarDecl whose parent is non-dependent and
4914 // whose type is not instantiation dependent, do nothing to the decl
4915 // - otherwise find its instantiated decl.
4916 if (isa<ParmVarDecl>(D) && !ParentDC->isDependentContext() &&
4917 !cast<ParmVarDecl>(D)->getType()->isInstantiationDependentType())
4919 if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
4920 isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
4921 (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext()) ||
4922 (isa<CXXRecordDecl>(D) && cast<CXXRecordDecl>(D)->isLambda())) {
4923 // D is a local of some kind. Look into the map of local
4924 // declarations to their instantiations.
4925 if (CurrentInstantiationScope) {
4926 if (auto Found = CurrentInstantiationScope->findInstantiationOf(D)) {
4927 if (Decl *FD = Found->dyn_cast<Decl *>())
4928 return cast<NamedDecl>(FD);
4930 int PackIdx = ArgumentPackSubstitutionIndex;
4931 assert(PackIdx != -1 &&
4932 "found declaration pack but not pack expanding");
4933 typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack;
4934 return cast<NamedDecl>((*Found->get<DeclArgumentPack *>())[PackIdx]);
4938 // If we're performing a partial substitution during template argument
4939 // deduction, we may not have values for template parameters yet. They
4940 // just map to themselves.
4941 if (isa<NonTypeTemplateParmDecl>(D) || isa<TemplateTypeParmDecl>(D) ||
4942 isa<TemplateTemplateParmDecl>(D))
4945 if (D->isInvalidDecl())
4948 // Normally this function only searches for already instantiated declaration
4949 // however we have to make an exclusion for local types used before
4950 // definition as in the code:
4952 // template<typename T> void f1() {
4953 // void g1(struct x1);
4957 // In this case instantiation of the type of 'g1' requires definition of
4958 // 'x1', which is defined later. Error recovery may produce an enum used
4959 // before definition. In these cases we need to instantiate relevant
4960 // declarations here.
4961 bool NeedInstantiate = false;
4962 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D))
4963 NeedInstantiate = RD->isLocalClass();
4965 NeedInstantiate = isa<EnumDecl>(D);
4966 if (NeedInstantiate) {
4967 Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
4968 CurrentInstantiationScope->InstantiatedLocal(D, Inst);
4969 return cast<TypeDecl>(Inst);
4972 // If we didn't find the decl, then we must have a label decl that hasn't
4973 // been found yet. Lazily instantiate it and return it now.
4974 assert(isa<LabelDecl>(D));
4976 Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
4977 assert(Inst && "Failed to instantiate label??");
4979 CurrentInstantiationScope->InstantiatedLocal(D, Inst);
4980 return cast<LabelDecl>(Inst);
4983 // For variable template specializations, update those that are still
4985 if (VarTemplateSpecializationDecl *VarSpec =
4986 dyn_cast<VarTemplateSpecializationDecl>(D)) {
4987 bool InstantiationDependent = false;
4988 const TemplateArgumentListInfo &VarTemplateArgs =
4989 VarSpec->getTemplateArgsInfo();
4990 if (TemplateSpecializationType::anyDependentTemplateArguments(
4991 VarTemplateArgs, InstantiationDependent))
4992 D = cast<NamedDecl>(
4993 SubstDecl(D, VarSpec->getDeclContext(), TemplateArgs));
4997 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
4998 if (!Record->isDependentContext())
5001 // Determine whether this record is the "templated" declaration describing
5002 // a class template or class template partial specialization.
5003 ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
5005 ClassTemplate = ClassTemplate->getCanonicalDecl();
5006 else if (ClassTemplatePartialSpecializationDecl *PartialSpec
5007 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record))
5008 ClassTemplate = PartialSpec->getSpecializedTemplate()->getCanonicalDecl();
5010 // Walk the current context to find either the record or an instantiation of
5012 DeclContext *DC = CurContext;
5013 while (!DC->isFileContext()) {
5014 // If we're performing substitution while we're inside the template
5015 // definition, we'll find our own context. We're done.
5016 if (DC->Equals(Record))
5019 if (CXXRecordDecl *InstRecord = dyn_cast<CXXRecordDecl>(DC)) {
5020 // Check whether we're in the process of instantiating a class template
5021 // specialization of the template we're mapping.
5022 if (ClassTemplateSpecializationDecl *InstSpec
5023 = dyn_cast<ClassTemplateSpecializationDecl>(InstRecord)){
5024 ClassTemplateDecl *SpecTemplate = InstSpec->getSpecializedTemplate();
5025 if (ClassTemplate && isInstantiationOf(ClassTemplate, SpecTemplate))
5029 // Check whether we're in the process of instantiating a member class.
5030 if (isInstantiationOf(Record, InstRecord))
5034 // Move to the outer template scope.
5035 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) {
5036 if (FD->getFriendObjectKind() && FD->getDeclContext()->isFileContext()){
5037 DC = FD->getLexicalDeclContext();
5040 // An implicit deduction guide acts as if it's within the class template
5041 // specialization described by its name and first N template params.
5042 auto *Guide = dyn_cast<CXXDeductionGuideDecl>(FD);
5043 if (Guide && Guide->isImplicit()) {
5044 TemplateDecl *TD = Guide->getDeducedTemplate();
5045 // Convert the arguments to an "as-written" list.
5046 TemplateArgumentListInfo Args(Loc, Loc);
5047 for (TemplateArgument Arg : TemplateArgs.getInnermost().take_front(
5048 TD->getTemplateParameters()->size())) {
5049 ArrayRef<TemplateArgument> Unpacked(Arg);
5050 if (Arg.getKind() == TemplateArgument::Pack)
5051 Unpacked = Arg.pack_elements();
5052 for (TemplateArgument UnpackedArg : Unpacked)
5054 getTrivialTemplateArgumentLoc(UnpackedArg, QualType(), Loc));
5056 QualType T = CheckTemplateIdType(TemplateName(TD), Loc, Args);
5059 auto *SubstRecord = T->getAsCXXRecordDecl();
5060 assert(SubstRecord && "class template id not a class type?");
5061 // Check that this template-id names the primary template and not a
5062 // partial or explicit specialization. (In the latter cases, it's
5063 // meaningless to attempt to find an instantiation of D within the
5065 // FIXME: The standard doesn't say what should happen here.
5066 if (FindingInstantiatedContext &&
5067 usesPartialOrExplicitSpecialization(
5068 Loc, cast<ClassTemplateSpecializationDecl>(SubstRecord))) {
5069 Diag(Loc, diag::err_specialization_not_primary_template)
5070 << T << (SubstRecord->getTemplateSpecializationKind() ==
5071 TSK_ExplicitSpecialization);
5079 DC = DC->getParent();
5082 // Fall through to deal with other dependent record types (e.g.,
5083 // anonymous unions in class templates).
5086 if (!ParentDC->isDependentContext())
5089 ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
5093 if (ParentDC != D->getDeclContext()) {
5094 // We performed some kind of instantiation in the parent context,
5095 // so now we need to look into the instantiated parent context to
5096 // find the instantiation of the declaration D.
5098 // If our context used to be dependent, we may need to instantiate
5099 // it before performing lookup into that context.
5100 bool IsBeingInstantiated = false;
5101 if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
5102 if (!Spec->isDependentContext()) {
5103 QualType T = Context.getTypeDeclType(Spec);
5104 const RecordType *Tag = T->getAs<RecordType>();
5105 assert(Tag && "type of non-dependent record is not a RecordType");
5106 if (Tag->isBeingDefined())
5107 IsBeingInstantiated = true;
5108 if (!Tag->isBeingDefined() &&
5109 RequireCompleteType(Loc, T, diag::err_incomplete_type))
5112 ParentDC = Tag->getDecl();
5116 NamedDecl *Result = nullptr;
5117 // FIXME: If the name is a dependent name, this lookup won't necessarily
5118 // find it. Does that ever matter?
5119 if (auto Name = D->getDeclName()) {
5120 DeclarationNameInfo NameInfo(Name, D->getLocation());
5121 Name = SubstDeclarationNameInfo(NameInfo, TemplateArgs).getName();
5124 DeclContext::lookup_result Found = ParentDC->lookup(Name);
5125 Result = findInstantiationOf(Context, D, Found.begin(), Found.end());
5127 // Since we don't have a name for the entity we're looking for,
5128 // our only option is to walk through all of the declarations to
5129 // find that name. This will occur in a few cases:
5131 // - anonymous struct/union within a template
5132 // - unnamed class/struct/union/enum within a template
5134 // FIXME: Find a better way to find these instantiations!
5135 Result = findInstantiationOf(Context, D,
5136 ParentDC->decls_begin(),
5137 ParentDC->decls_end());
5141 if (isa<UsingShadowDecl>(D)) {
5142 // UsingShadowDecls can instantiate to nothing because of using hiding.
5143 } else if (Diags.hasErrorOccurred()) {
5144 // We've already complained about something, so most likely this
5145 // declaration failed to instantiate. There's no point in complaining
5146 // further, since this is normal in invalid code.
5147 } else if (IsBeingInstantiated) {
5148 // The class in which this member exists is currently being
5149 // instantiated, and we haven't gotten around to instantiating this
5150 // member yet. This can happen when the code uses forward declarations
5151 // of member classes, and introduces ordering dependencies via
5152 // template instantiation.
5153 Diag(Loc, diag::err_member_not_yet_instantiated)
5155 << Context.getTypeDeclType(cast<CXXRecordDecl>(ParentDC));
5156 Diag(D->getLocation(), diag::note_non_instantiated_member_here);
5157 } else if (EnumConstantDecl *ED = dyn_cast<EnumConstantDecl>(D)) {
5158 // This enumeration constant was found when the template was defined,
5159 // but can't be found in the instantiation. This can happen if an
5160 // unscoped enumeration member is explicitly specialized.
5161 EnumDecl *Enum = cast<EnumDecl>(ED->getLexicalDeclContext());
5162 EnumDecl *Spec = cast<EnumDecl>(FindInstantiatedDecl(Loc, Enum,
5164 assert(Spec->getTemplateSpecializationKind() ==
5165 TSK_ExplicitSpecialization);
5166 Diag(Loc, diag::err_enumerator_does_not_exist)
5168 << Context.getTypeDeclType(cast<TypeDecl>(Spec->getDeclContext()));
5169 Diag(Spec->getLocation(), diag::note_enum_specialized_here)
5170 << Context.getTypeDeclType(Spec);
5172 // We should have found something, but didn't.
5173 llvm_unreachable("Unable to find instantiation of declaration!");
5183 /// \brief Performs template instantiation for all implicit template
5184 /// instantiations we have seen until this point.
5185 void Sema::PerformPendingInstantiations(bool LocalOnly) {
5186 while (!PendingLocalImplicitInstantiations.empty() ||
5187 (!LocalOnly && !PendingInstantiations.empty())) {
5188 PendingImplicitInstantiation Inst;
5190 if (PendingLocalImplicitInstantiations.empty()) {
5191 Inst = PendingInstantiations.front();
5192 PendingInstantiations.pop_front();
5194 Inst = PendingLocalImplicitInstantiations.front();
5195 PendingLocalImplicitInstantiations.pop_front();
5198 // Instantiate function definitions
5199 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
5200 bool DefinitionRequired = Function->getTemplateSpecializationKind() ==
5201 TSK_ExplicitInstantiationDefinition;
5202 InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true,
5203 DefinitionRequired, true);
5204 if (Function->isDefined())
5205 Function->setInstantiationIsPending(false);
5209 // Instantiate variable definitions
5210 VarDecl *Var = cast<VarDecl>(Inst.first);
5212 assert((Var->isStaticDataMember() ||
5213 isa<VarTemplateSpecializationDecl>(Var)) &&
5214 "Not a static data member, nor a variable template"
5215 " specialization?");
5217 // Don't try to instantiate declarations if the most recent redeclaration
5219 if (Var->getMostRecentDecl()->isInvalidDecl())
5222 // Check if the most recent declaration has changed the specialization kind
5223 // and removed the need for implicit instantiation.
5224 switch (Var->getMostRecentDecl()->getTemplateSpecializationKind()) {
5225 case TSK_Undeclared:
5226 llvm_unreachable("Cannot instantitiate an undeclared specialization.");
5227 case TSK_ExplicitInstantiationDeclaration:
5228 case TSK_ExplicitSpecialization:
5229 continue; // No longer need to instantiate this type.
5230 case TSK_ExplicitInstantiationDefinition:
5231 // We only need an instantiation if the pending instantiation *is* the
5232 // explicit instantiation.
5233 if (Var != Var->getMostRecentDecl())
5236 case TSK_ImplicitInstantiation:
5240 PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
5241 "instantiating variable definition");
5242 bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
5243 TSK_ExplicitInstantiationDefinition;
5245 // Instantiate static data member definitions or variable template
5247 InstantiateVariableDefinition(/*FIXME:*/ Inst.second, Var, true,
5248 DefinitionRequired, true);
5252 void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
5253 const MultiLevelTemplateArgumentList &TemplateArgs) {
5254 for (auto DD : Pattern->ddiags()) {
5255 switch (DD->getKind()) {
5256 case DependentDiagnostic::Access:
5257 HandleDependentAccessCheck(*DD, TemplateArgs);