1 //===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //===----------------------------------------------------------------------===/
9 // This file implements C++ template instantiation for declarations.
11 //===----------------------------------------------------------------------===/
12 #include "clang/Sema/SemaInternal.h"
13 #include "clang/AST/ASTConsumer.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/ASTMutationListener.h"
16 #include "clang/AST/DeclTemplate.h"
17 #include "clang/AST/DeclVisitor.h"
18 #include "clang/AST/DependentDiagnostic.h"
19 #include "clang/AST/Expr.h"
20 #include "clang/AST/ExprCXX.h"
21 #include "clang/AST/TypeLoc.h"
22 #include "clang/Sema/Initialization.h"
23 #include "clang/Sema/Lookup.h"
24 #include "clang/Sema/PrettyDeclStackTrace.h"
25 #include "clang/Sema/Template.h"
27 using namespace clang;
29 static bool isDeclWithinFunction(const Decl *D) {
30 const DeclContext *DC = D->getDeclContext();
31 if (DC->isFunctionOrMethod())
35 return cast<CXXRecordDecl>(DC)->isLocalClass();
40 template<typename DeclT>
41 static bool SubstQualifier(Sema &SemaRef, const DeclT *OldDecl, DeclT *NewDecl,
42 const MultiLevelTemplateArgumentList &TemplateArgs) {
43 if (!OldDecl->getQualifierLoc())
46 assert((NewDecl->getFriendObjectKind() ||
47 !OldDecl->getLexicalDeclContext()->isDependentContext()) &&
48 "non-friend with qualified name defined in dependent context");
49 Sema::ContextRAII SavedContext(
51 const_cast<DeclContext *>(NewDecl->getFriendObjectKind()
52 ? NewDecl->getLexicalDeclContext()
53 : OldDecl->getLexicalDeclContext()));
55 NestedNameSpecifierLoc NewQualifierLoc
56 = SemaRef.SubstNestedNameSpecifierLoc(OldDecl->getQualifierLoc(),
62 NewDecl->setQualifierInfo(NewQualifierLoc);
66 bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
67 DeclaratorDecl *NewDecl) {
68 return ::SubstQualifier(SemaRef, OldDecl, NewDecl, TemplateArgs);
71 bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
73 return ::SubstQualifier(SemaRef, OldDecl, NewDecl, TemplateArgs);
76 // Include attribute instantiation code.
77 #include "clang/Sema/AttrTemplateInstantiate.inc"
79 static void instantiateDependentAlignedAttr(
80 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
81 const AlignedAttr *Aligned, Decl *New, bool IsPackExpansion) {
82 if (Aligned->isAlignmentExpr()) {
83 // The alignment expression is a constant expression.
84 EnterExpressionEvaluationContext Unevaluated(
85 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
86 ExprResult Result = S.SubstExpr(Aligned->getAlignmentExpr(), TemplateArgs);
87 if (!Result.isInvalid())
88 S.AddAlignedAttr(Aligned->getLocation(), New, Result.getAs<Expr>(),
89 Aligned->getSpellingListIndex(), IsPackExpansion);
91 TypeSourceInfo *Result = S.SubstType(Aligned->getAlignmentType(),
92 TemplateArgs, Aligned->getLocation(),
95 S.AddAlignedAttr(Aligned->getLocation(), New, Result,
96 Aligned->getSpellingListIndex(), IsPackExpansion);
100 static void instantiateDependentAlignedAttr(
101 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
102 const AlignedAttr *Aligned, Decl *New) {
103 if (!Aligned->isPackExpansion()) {
104 instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
108 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
109 if (Aligned->isAlignmentExpr())
110 S.collectUnexpandedParameterPacks(Aligned->getAlignmentExpr(),
113 S.collectUnexpandedParameterPacks(Aligned->getAlignmentType()->getTypeLoc(),
115 assert(!Unexpanded.empty() && "Pack expansion without parameter packs?");
117 // Determine whether we can expand this attribute pack yet.
118 bool Expand = true, RetainExpansion = false;
119 Optional<unsigned> NumExpansions;
120 // FIXME: Use the actual location of the ellipsis.
121 SourceLocation EllipsisLoc = Aligned->getLocation();
122 if (S.CheckParameterPacksForExpansion(EllipsisLoc, Aligned->getRange(),
123 Unexpanded, TemplateArgs, Expand,
124 RetainExpansion, NumExpansions))
128 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, -1);
129 instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, true);
131 for (unsigned I = 0; I != *NumExpansions; ++I) {
132 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, I);
133 instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
138 static void instantiateDependentAssumeAlignedAttr(
139 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
140 const AssumeAlignedAttr *Aligned, Decl *New) {
141 // The alignment expression is a constant expression.
142 EnterExpressionEvaluationContext Unevaluated(
143 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
145 Expr *E, *OE = nullptr;
146 ExprResult Result = S.SubstExpr(Aligned->getAlignment(), TemplateArgs);
147 if (Result.isInvalid())
149 E = Result.getAs<Expr>();
151 if (Aligned->getOffset()) {
152 Result = S.SubstExpr(Aligned->getOffset(), TemplateArgs);
153 if (Result.isInvalid())
155 OE = Result.getAs<Expr>();
158 S.AddAssumeAlignedAttr(Aligned->getLocation(), New, E, OE,
159 Aligned->getSpellingListIndex());
162 static void instantiateDependentAlignValueAttr(
163 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
164 const AlignValueAttr *Aligned, Decl *New) {
165 // The alignment expression is a constant expression.
166 EnterExpressionEvaluationContext Unevaluated(
167 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
168 ExprResult Result = S.SubstExpr(Aligned->getAlignment(), TemplateArgs);
169 if (!Result.isInvalid())
170 S.AddAlignValueAttr(Aligned->getLocation(), New, Result.getAs<Expr>(),
171 Aligned->getSpellingListIndex());
174 static void instantiateDependentAllocAlignAttr(
175 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
176 const AllocAlignAttr *Align, Decl *New) {
177 Expr *Param = IntegerLiteral::Create(
178 S.getASTContext(), llvm::APInt(64, Align->getParamIndex()),
179 S.getASTContext().UnsignedLongLongTy, Align->getLocation());
180 S.AddAllocAlignAttr(Align->getLocation(), New, Param,
181 Align->getSpellingListIndex());
184 static Expr *instantiateDependentFunctionAttrCondition(
185 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
186 const Attr *A, Expr *OldCond, const Decl *Tmpl, FunctionDecl *New) {
187 Expr *Cond = nullptr;
189 Sema::ContextRAII SwitchContext(S, New);
190 EnterExpressionEvaluationContext Unevaluated(
191 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
192 ExprResult Result = S.SubstExpr(OldCond, TemplateArgs);
193 if (Result.isInvalid())
195 Cond = Result.getAs<Expr>();
197 if (!Cond->isTypeDependent()) {
198 ExprResult Converted = S.PerformContextuallyConvertToBool(Cond);
199 if (Converted.isInvalid())
201 Cond = Converted.get();
204 SmallVector<PartialDiagnosticAt, 8> Diags;
205 if (OldCond->isValueDependent() && !Cond->isValueDependent() &&
206 !Expr::isPotentialConstantExprUnevaluated(Cond, New, Diags)) {
207 S.Diag(A->getLocation(), diag::err_attr_cond_never_constant_expr) << A;
208 for (const auto &P : Diags)
209 S.Diag(P.first, P.second);
215 static void instantiateDependentEnableIfAttr(
216 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
217 const EnableIfAttr *EIA, const Decl *Tmpl, FunctionDecl *New) {
218 Expr *Cond = instantiateDependentFunctionAttrCondition(
219 S, TemplateArgs, EIA, EIA->getCond(), Tmpl, New);
222 New->addAttr(new (S.getASTContext()) EnableIfAttr(
223 EIA->getLocation(), S.getASTContext(), Cond, EIA->getMessage(),
224 EIA->getSpellingListIndex()));
227 static void instantiateDependentDiagnoseIfAttr(
228 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
229 const DiagnoseIfAttr *DIA, const Decl *Tmpl, FunctionDecl *New) {
230 Expr *Cond = instantiateDependentFunctionAttrCondition(
231 S, TemplateArgs, DIA, DIA->getCond(), Tmpl, New);
234 New->addAttr(new (S.getASTContext()) DiagnoseIfAttr(
235 DIA->getLocation(), S.getASTContext(), Cond, DIA->getMessage(),
236 DIA->getDiagnosticType(), DIA->getArgDependent(), New,
237 DIA->getSpellingListIndex()));
240 // Constructs and adds to New a new instance of CUDALaunchBoundsAttr using
241 // template A as the base and arguments from TemplateArgs.
242 static void instantiateDependentCUDALaunchBoundsAttr(
243 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
244 const CUDALaunchBoundsAttr &Attr, Decl *New) {
245 // The alignment expression is a constant expression.
246 EnterExpressionEvaluationContext Unevaluated(
247 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
249 ExprResult Result = S.SubstExpr(Attr.getMaxThreads(), TemplateArgs);
250 if (Result.isInvalid())
252 Expr *MaxThreads = Result.getAs<Expr>();
254 Expr *MinBlocks = nullptr;
255 if (Attr.getMinBlocks()) {
256 Result = S.SubstExpr(Attr.getMinBlocks(), TemplateArgs);
257 if (Result.isInvalid())
259 MinBlocks = Result.getAs<Expr>();
262 S.AddLaunchBoundsAttr(Attr.getLocation(), New, MaxThreads, MinBlocks,
263 Attr.getSpellingListIndex());
267 instantiateDependentModeAttr(Sema &S,
268 const MultiLevelTemplateArgumentList &TemplateArgs,
269 const ModeAttr &Attr, Decl *New) {
270 S.AddModeAttr(Attr.getRange(), New, Attr.getMode(),
271 Attr.getSpellingListIndex(), /*InInstantiation=*/true);
274 /// Instantiation of 'declare simd' attribute and its arguments.
275 static void instantiateOMPDeclareSimdDeclAttr(
276 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
277 const OMPDeclareSimdDeclAttr &Attr, Decl *New) {
278 // Allow 'this' in clauses with varlists.
279 if (auto *FTD = dyn_cast<FunctionTemplateDecl>(New))
280 New = FTD->getTemplatedDecl();
281 auto *FD = cast<FunctionDecl>(New);
282 auto *ThisContext = dyn_cast_or_null<CXXRecordDecl>(FD->getDeclContext());
283 SmallVector<Expr *, 4> Uniforms, Aligneds, Alignments, Linears, Steps;
284 SmallVector<unsigned, 4> LinModifiers;
286 auto &&Subst = [&](Expr *E) -> ExprResult {
287 if (auto *DRE = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()))
288 if (auto *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl())) {
289 Sema::ContextRAII SavedContext(S, FD);
290 LocalInstantiationScope Local(S);
291 if (FD->getNumParams() > PVD->getFunctionScopeIndex())
292 Local.InstantiatedLocal(
293 PVD, FD->getParamDecl(PVD->getFunctionScopeIndex()));
294 return S.SubstExpr(E, TemplateArgs);
296 Sema::CXXThisScopeRAII ThisScope(S, ThisContext, /*TypeQuals=*/0,
297 FD->isCXXInstanceMember());
298 return S.SubstExpr(E, TemplateArgs);
302 if (auto *E = Attr.getSimdlen())
305 if (Attr.uniforms_size() > 0) {
306 for(auto *E : Attr.uniforms()) {
307 ExprResult Inst = Subst(E);
308 if (Inst.isInvalid())
310 Uniforms.push_back(Inst.get());
314 auto AI = Attr.alignments_begin();
315 for (auto *E : Attr.aligneds()) {
316 ExprResult Inst = Subst(E);
317 if (Inst.isInvalid())
319 Aligneds.push_back(Inst.get());
322 Inst = S.SubstExpr(*AI, TemplateArgs);
323 Alignments.push_back(Inst.get());
327 auto SI = Attr.steps_begin();
328 for (auto *E : Attr.linears()) {
329 ExprResult Inst = Subst(E);
330 if (Inst.isInvalid())
332 Linears.push_back(Inst.get());
335 Inst = S.SubstExpr(*SI, TemplateArgs);
336 Steps.push_back(Inst.get());
339 LinModifiers.append(Attr.modifiers_begin(), Attr.modifiers_end());
340 (void)S.ActOnOpenMPDeclareSimdDirective(
341 S.ConvertDeclToDeclGroup(New), Attr.getBranchState(), Simdlen.get(),
342 Uniforms, Aligneds, Alignments, Linears, LinModifiers, Steps,
346 static bool DeclContainsAttr(const Decl *D, const Attr *NewAttr) {
347 if (!D->hasAttrs() || NewAttr->duplicatesAllowed())
349 return llvm::find_if(D->getAttrs(), [NewAttr](const Attr *Attr) {
350 return Attr->getKind() == NewAttr->getKind();
351 }) != D->getAttrs().end();
354 void Sema::InstantiateAttrsForDecl(
355 const MultiLevelTemplateArgumentList &TemplateArgs, const Decl *Tmpl,
356 Decl *New, LateInstantiatedAttrVec *LateAttrs,
357 LocalInstantiationScope *OuterMostScope) {
358 if (NamedDecl *ND = dyn_cast<NamedDecl>(New)) {
359 for (const auto *TmplAttr : Tmpl->attrs()) {
360 // FIXME: If any of the special case versions from InstantiateAttrs become
361 // applicable to template declaration, we'll need to add them here.
362 CXXThisScopeRAII ThisScope(
363 *this, dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext()),
364 /*TypeQuals*/ 0, ND->isCXXInstanceMember());
366 Attr *NewAttr = sema::instantiateTemplateAttributeForDecl(
367 TmplAttr, Context, *this, TemplateArgs);
368 if (NewAttr && !DeclContainsAttr(New, NewAttr))
369 New->addAttr(NewAttr);
374 void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
375 const Decl *Tmpl, Decl *New,
376 LateInstantiatedAttrVec *LateAttrs,
377 LocalInstantiationScope *OuterMostScope) {
378 for (const auto *TmplAttr : Tmpl->attrs()) {
379 // FIXME: This should be generalized to more than just the AlignedAttr.
380 const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr);
381 if (Aligned && Aligned->isAlignmentDependent()) {
382 instantiateDependentAlignedAttr(*this, TemplateArgs, Aligned, New);
386 const AssumeAlignedAttr *AssumeAligned = dyn_cast<AssumeAlignedAttr>(TmplAttr);
388 instantiateDependentAssumeAlignedAttr(*this, TemplateArgs, AssumeAligned, New);
392 const AlignValueAttr *AlignValue = dyn_cast<AlignValueAttr>(TmplAttr);
394 instantiateDependentAlignValueAttr(*this, TemplateArgs, AlignValue, New);
398 if (const auto *AllocAlign = dyn_cast<AllocAlignAttr>(TmplAttr)) {
399 instantiateDependentAllocAlignAttr(*this, TemplateArgs, AllocAlign, New);
404 if (const auto *EnableIf = dyn_cast<EnableIfAttr>(TmplAttr)) {
405 instantiateDependentEnableIfAttr(*this, TemplateArgs, EnableIf, Tmpl,
406 cast<FunctionDecl>(New));
410 if (const auto *DiagnoseIf = dyn_cast<DiagnoseIfAttr>(TmplAttr)) {
411 instantiateDependentDiagnoseIfAttr(*this, TemplateArgs, DiagnoseIf, Tmpl,
412 cast<FunctionDecl>(New));
416 if (const CUDALaunchBoundsAttr *CUDALaunchBounds =
417 dyn_cast<CUDALaunchBoundsAttr>(TmplAttr)) {
418 instantiateDependentCUDALaunchBoundsAttr(*this, TemplateArgs,
419 *CUDALaunchBounds, New);
423 if (const ModeAttr *Mode = dyn_cast<ModeAttr>(TmplAttr)) {
424 instantiateDependentModeAttr(*this, TemplateArgs, *Mode, New);
428 if (const auto *OMPAttr = dyn_cast<OMPDeclareSimdDeclAttr>(TmplAttr)) {
429 instantiateOMPDeclareSimdDeclAttr(*this, TemplateArgs, *OMPAttr, New);
433 // Existing DLL attribute on the instantiation takes precedence.
434 if (TmplAttr->getKind() == attr::DLLExport ||
435 TmplAttr->getKind() == attr::DLLImport) {
436 if (New->hasAttr<DLLExportAttr>() || New->hasAttr<DLLImportAttr>()) {
441 if (auto ABIAttr = dyn_cast<ParameterABIAttr>(TmplAttr)) {
442 AddParameterABIAttr(ABIAttr->getRange(), New, ABIAttr->getABI(),
443 ABIAttr->getSpellingListIndex());
447 if (isa<NSConsumedAttr>(TmplAttr) || isa<CFConsumedAttr>(TmplAttr)) {
448 AddNSConsumedAttr(TmplAttr->getRange(), New,
449 TmplAttr->getSpellingListIndex(),
450 isa<NSConsumedAttr>(TmplAttr),
451 /*template instantiation*/ true);
455 assert(!TmplAttr->isPackExpansion());
456 if (TmplAttr->isLateParsed() && LateAttrs) {
457 // Late parsed attributes must be instantiated and attached after the
458 // enclosing class has been instantiated. See Sema::InstantiateClass.
459 LocalInstantiationScope *Saved = nullptr;
460 if (CurrentInstantiationScope)
461 Saved = CurrentInstantiationScope->cloneScopes(OuterMostScope);
462 LateAttrs->push_back(LateInstantiatedAttribute(TmplAttr, Saved, New));
464 // Allow 'this' within late-parsed attributes.
465 NamedDecl *ND = dyn_cast<NamedDecl>(New);
466 CXXRecordDecl *ThisContext =
467 dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext());
468 CXXThisScopeRAII ThisScope(*this, ThisContext, /*TypeQuals*/0,
469 ND && ND->isCXXInstanceMember());
471 Attr *NewAttr = sema::instantiateTemplateAttribute(TmplAttr, Context,
472 *this, TemplateArgs);
474 if (NewAttr && !DeclContainsAttr(New, NewAttr))
475 New->addAttr(NewAttr);
480 /// Get the previous declaration of a declaration for the purposes of template
481 /// instantiation. If this finds a previous declaration, then the previous
482 /// declaration of the instantiation of D should be an instantiation of the
483 /// result of this function.
484 template<typename DeclT>
485 static DeclT *getPreviousDeclForInstantiation(DeclT *D) {
486 DeclT *Result = D->getPreviousDecl();
488 // If the declaration is within a class, and the previous declaration was
489 // merged from a different definition of that class, then we don't have a
490 // previous declaration for the purpose of template instantiation.
491 if (Result && isa<CXXRecordDecl>(D->getDeclContext()) &&
492 D->getLexicalDeclContext() != Result->getLexicalDeclContext())
499 TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
500 llvm_unreachable("Translation units cannot be instantiated");
504 TemplateDeclInstantiator::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
505 llvm_unreachable("pragma comment cannot be instantiated");
508 Decl *TemplateDeclInstantiator::VisitPragmaDetectMismatchDecl(
509 PragmaDetectMismatchDecl *D) {
510 llvm_unreachable("pragma comment cannot be instantiated");
514 TemplateDeclInstantiator::VisitExternCContextDecl(ExternCContextDecl *D) {
515 llvm_unreachable("extern \"C\" context cannot be instantiated");
519 TemplateDeclInstantiator::VisitLabelDecl(LabelDecl *D) {
520 LabelDecl *Inst = LabelDecl::Create(SemaRef.Context, Owner, D->getLocation(),
522 Owner->addDecl(Inst);
527 TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
528 llvm_unreachable("Namespaces cannot be instantiated");
532 TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
533 NamespaceAliasDecl *Inst
534 = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
535 D->getNamespaceLoc(),
538 D->getQualifierLoc(),
539 D->getTargetNameLoc(),
541 Owner->addDecl(Inst);
545 Decl *TemplateDeclInstantiator::InstantiateTypedefNameDecl(TypedefNameDecl *D,
547 bool Invalid = false;
548 TypeSourceInfo *DI = D->getTypeSourceInfo();
549 if (DI->getType()->isInstantiationDependentType() ||
550 DI->getType()->isVariablyModifiedType()) {
551 DI = SemaRef.SubstType(DI, TemplateArgs,
552 D->getLocation(), D->getDeclName());
555 DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
558 SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
561 // HACK: g++ has a bug where it gets the value kind of ?: wrong.
562 // libstdc++ relies upon this bug in its implementation of common_type.
563 // If we happen to be processing that implementation, fake up the g++ ?:
564 // semantics. See LWG issue 2141 for more information on the bug.
565 const DecltypeType *DT = DI->getType()->getAs<DecltypeType>();
566 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D->getDeclContext());
567 if (DT && RD && isa<ConditionalOperator>(DT->getUnderlyingExpr()) &&
568 DT->isReferenceType() &&
569 RD->getEnclosingNamespaceContext() == SemaRef.getStdNamespace() &&
570 RD->getIdentifier() && RD->getIdentifier()->isStr("common_type") &&
571 D->getIdentifier() && D->getIdentifier()->isStr("type") &&
572 SemaRef.getSourceManager().isInSystemHeader(D->getLocStart()))
573 // Fold it to the (non-reference) type which g++ would have produced.
574 DI = SemaRef.Context.getTrivialTypeSourceInfo(
575 DI->getType().getNonReferenceType());
577 // Create the new typedef
578 TypedefNameDecl *Typedef;
580 Typedef = TypeAliasDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
581 D->getLocation(), D->getIdentifier(), DI);
583 Typedef = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
584 D->getLocation(), D->getIdentifier(), DI);
586 Typedef->setInvalidDecl();
588 // If the old typedef was the name for linkage purposes of an anonymous
589 // tag decl, re-establish that relationship for the new typedef.
590 if (const TagType *oldTagType = D->getUnderlyingType()->getAs<TagType>()) {
591 TagDecl *oldTag = oldTagType->getDecl();
592 if (oldTag->getTypedefNameForAnonDecl() == D && !Invalid) {
593 TagDecl *newTag = DI->getType()->castAs<TagType>()->getDecl();
594 assert(!newTag->hasNameForLinkage());
595 newTag->setTypedefNameForAnonDecl(Typedef);
599 if (TypedefNameDecl *Prev = getPreviousDeclForInstantiation(D)) {
600 NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
605 TypedefNameDecl *InstPrevTypedef = cast<TypedefNameDecl>(InstPrev);
607 // If the typedef types are not identical, reject them.
608 SemaRef.isIncompatibleTypedef(InstPrevTypedef, Typedef);
610 Typedef->setPreviousDecl(InstPrevTypedef);
613 SemaRef.InstantiateAttrs(TemplateArgs, D, Typedef);
615 Typedef->setAccess(D->getAccess());
620 Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
621 Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/false);
623 Owner->addDecl(Typedef);
627 Decl *TemplateDeclInstantiator::VisitTypeAliasDecl(TypeAliasDecl *D) {
628 Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/true);
630 Owner->addDecl(Typedef);
635 TemplateDeclInstantiator::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
636 // Create a local instantiation scope for this type alias template, which
637 // will contain the instantiations of the template parameters.
638 LocalInstantiationScope Scope(SemaRef);
640 TemplateParameterList *TempParams = D->getTemplateParameters();
641 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
645 TypeAliasDecl *Pattern = D->getTemplatedDecl();
647 TypeAliasTemplateDecl *PrevAliasTemplate = nullptr;
648 if (getPreviousDeclForInstantiation<TypedefNameDecl>(Pattern)) {
649 DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
650 if (!Found.empty()) {
651 PrevAliasTemplate = dyn_cast<TypeAliasTemplateDecl>(Found.front());
655 TypeAliasDecl *AliasInst = cast_or_null<TypeAliasDecl>(
656 InstantiateTypedefNameDecl(Pattern, /*IsTypeAlias=*/true));
660 TypeAliasTemplateDecl *Inst
661 = TypeAliasTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
662 D->getDeclName(), InstParams, AliasInst);
663 AliasInst->setDescribedAliasTemplate(Inst);
664 if (PrevAliasTemplate)
665 Inst->setPreviousDecl(PrevAliasTemplate);
667 Inst->setAccess(D->getAccess());
669 if (!PrevAliasTemplate)
670 Inst->setInstantiatedFromMemberTemplate(D);
672 Owner->addDecl(Inst);
677 Decl *TemplateDeclInstantiator::VisitBindingDecl(BindingDecl *D) {
678 auto *NewBD = BindingDecl::Create(SemaRef.Context, Owner, D->getLocation(),
680 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewBD);
684 Decl *TemplateDeclInstantiator::VisitDecompositionDecl(DecompositionDecl *D) {
685 // Transform the bindings first.
686 SmallVector<BindingDecl*, 16> NewBindings;
687 for (auto *OldBD : D->bindings())
688 NewBindings.push_back(cast<BindingDecl>(VisitBindingDecl(OldBD)));
689 ArrayRef<BindingDecl*> NewBindingArray = NewBindings;
691 auto *NewDD = cast_or_null<DecompositionDecl>(
692 VisitVarDecl(D, /*InstantiatingVarTemplate=*/false, &NewBindingArray));
694 if (!NewDD || NewDD->isInvalidDecl())
695 for (auto *NewBD : NewBindings)
696 NewBD->setInvalidDecl();
701 Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
702 return VisitVarDecl(D, /*InstantiatingVarTemplate=*/false);
705 Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D,
706 bool InstantiatingVarTemplate,
707 ArrayRef<BindingDecl*> *Bindings) {
709 // Do substitution on the type of the declaration
710 TypeSourceInfo *DI = SemaRef.SubstType(
711 D->getTypeSourceInfo(), TemplateArgs, D->getTypeSpecStartLoc(),
712 D->getDeclName(), /*AllowDeducedTST*/true);
716 if (DI->getType()->isFunctionType()) {
717 SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
718 << D->isStaticDataMember() << DI->getType();
722 DeclContext *DC = Owner;
723 if (D->isLocalExternDecl())
724 SemaRef.adjustContextForLocalExternDecl(DC);
726 // Build the instantiated declaration.
729 Var = DecompositionDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
730 D->getLocation(), DI->getType(), DI,
731 D->getStorageClass(), *Bindings);
733 Var = VarDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
734 D->getLocation(), D->getIdentifier(), DI->getType(),
735 DI, D->getStorageClass());
737 // In ARC, infer 'retaining' for variables of retainable type.
738 if (SemaRef.getLangOpts().ObjCAutoRefCount &&
739 SemaRef.inferObjCARCLifetime(Var))
740 Var->setInvalidDecl();
742 // Substitute the nested name specifier, if any.
743 if (SubstQualifier(D, Var))
746 SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs, Owner,
747 StartingScope, InstantiatingVarTemplate);
749 if (D->isNRVOVariable()) {
750 QualType ReturnType = cast<FunctionDecl>(DC)->getReturnType();
751 if (SemaRef.isCopyElisionCandidate(ReturnType, Var, false))
752 Var->setNRVOVariable(true);
755 Var->setImplicit(D->isImplicit());
760 Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
762 = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
763 D->getAccessSpecifierLoc(), D->getColonLoc());
764 Owner->addHiddenDecl(AD);
768 Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
769 bool Invalid = false;
770 TypeSourceInfo *DI = D->getTypeSourceInfo();
771 if (DI->getType()->isInstantiationDependentType() ||
772 DI->getType()->isVariablyModifiedType()) {
773 DI = SemaRef.SubstType(DI, TemplateArgs,
774 D->getLocation(), D->getDeclName());
776 DI = D->getTypeSourceInfo();
778 } else if (DI->getType()->isFunctionType()) {
779 // C++ [temp.arg.type]p3:
780 // If a declaration acquires a function type through a type
781 // dependent on a template-parameter and this causes a
782 // declaration that does not use the syntactic form of a
783 // function declarator to have function type, the program is
785 SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
790 SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
793 Expr *BitWidth = D->getBitWidth();
797 // The bit-width expression is a constant expression.
798 EnterExpressionEvaluationContext Unevaluated(
799 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
801 ExprResult InstantiatedBitWidth
802 = SemaRef.SubstExpr(BitWidth, TemplateArgs);
803 if (InstantiatedBitWidth.isInvalid()) {
807 BitWidth = InstantiatedBitWidth.getAs<Expr>();
810 FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
812 cast<RecordDecl>(Owner),
816 D->getInClassInitStyle(),
817 D->getInnerLocStart(),
821 cast<Decl>(Owner)->setInvalidDecl();
825 SemaRef.InstantiateAttrs(TemplateArgs, D, Field, LateAttrs, StartingScope);
827 if (Field->hasAttrs())
828 SemaRef.CheckAlignasUnderalignment(Field);
831 Field->setInvalidDecl();
833 if (!Field->getDeclName()) {
834 // Keep track of where this decl came from.
835 SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
837 if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
838 if (Parent->isAnonymousStructOrUnion() &&
839 Parent->getRedeclContext()->isFunctionOrMethod())
840 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
843 Field->setImplicit(D->isImplicit());
844 Field->setAccess(D->getAccess());
845 Owner->addDecl(Field);
850 Decl *TemplateDeclInstantiator::VisitMSPropertyDecl(MSPropertyDecl *D) {
851 bool Invalid = false;
852 TypeSourceInfo *DI = D->getTypeSourceInfo();
854 if (DI->getType()->isVariablyModifiedType()) {
855 SemaRef.Diag(D->getLocation(), diag::err_property_is_variably_modified)
858 } else if (DI->getType()->isInstantiationDependentType()) {
859 DI = SemaRef.SubstType(DI, TemplateArgs,
860 D->getLocation(), D->getDeclName());
862 DI = D->getTypeSourceInfo();
864 } else if (DI->getType()->isFunctionType()) {
865 // C++ [temp.arg.type]p3:
866 // If a declaration acquires a function type through a type
867 // dependent on a template-parameter and this causes a
868 // declaration that does not use the syntactic form of a
869 // function declarator to have function type, the program is
871 SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
876 SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
879 MSPropertyDecl *Property = MSPropertyDecl::Create(
880 SemaRef.Context, Owner, D->getLocation(), D->getDeclName(), DI->getType(),
881 DI, D->getLocStart(), D->getGetterId(), D->getSetterId());
883 SemaRef.InstantiateAttrs(TemplateArgs, D, Property, LateAttrs,
887 Property->setInvalidDecl();
889 Property->setAccess(D->getAccess());
890 Owner->addDecl(Property);
895 Decl *TemplateDeclInstantiator::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
896 NamedDecl **NamedChain =
897 new (SemaRef.Context)NamedDecl*[D->getChainingSize()];
900 for (auto *PI : D->chain()) {
901 NamedDecl *Next = SemaRef.FindInstantiatedDecl(D->getLocation(), PI,
906 NamedChain[i++] = Next;
909 QualType T = cast<FieldDecl>(NamedChain[i-1])->getType();
910 IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
911 SemaRef.Context, Owner, D->getLocation(), D->getIdentifier(), T,
912 {NamedChain, D->getChainingSize()});
914 for (const auto *Attr : D->attrs())
915 IndirectField->addAttr(Attr->clone(SemaRef.Context));
917 IndirectField->setImplicit(D->isImplicit());
918 IndirectField->setAccess(D->getAccess());
919 Owner->addDecl(IndirectField);
920 return IndirectField;
923 Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
924 // Handle friend type expressions by simply substituting template
925 // parameters into the pattern type and checking the result.
926 if (TypeSourceInfo *Ty = D->getFriendType()) {
927 TypeSourceInfo *InstTy;
928 // If this is an unsupported friend, don't bother substituting template
929 // arguments into it. The actual type referred to won't be used by any
930 // parts of Clang, and may not be valid for instantiating. Just use the
931 // same info for the instantiated friend.
932 if (D->isUnsupportedFriend()) {
935 InstTy = SemaRef.SubstType(Ty, TemplateArgs,
936 D->getLocation(), DeclarationName());
941 FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getLocStart(),
942 D->getFriendLoc(), InstTy);
946 FD->setAccess(AS_public);
947 FD->setUnsupportedFriend(D->isUnsupportedFriend());
952 NamedDecl *ND = D->getFriendDecl();
953 assert(ND && "friend decl must be a decl or a type!");
955 // All of the Visit implementations for the various potential friend
956 // declarations have to be carefully written to work for friend
957 // objects, with the most important detail being that the target
958 // decl should almost certainly not be placed in Owner.
959 Decl *NewND = Visit(ND);
960 if (!NewND) return nullptr;
963 FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
964 cast<NamedDecl>(NewND), D->getFriendLoc());
965 FD->setAccess(AS_public);
966 FD->setUnsupportedFriend(D->isUnsupportedFriend());
971 Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
972 Expr *AssertExpr = D->getAssertExpr();
974 // The expression in a static assertion is a constant expression.
975 EnterExpressionEvaluationContext Unevaluated(
976 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
978 ExprResult InstantiatedAssertExpr
979 = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
980 if (InstantiatedAssertExpr.isInvalid())
983 return SemaRef.BuildStaticAssertDeclaration(D->getLocation(),
984 InstantiatedAssertExpr.get(),
990 Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
991 EnumDecl *PrevDecl = nullptr;
992 if (EnumDecl *PatternPrev = getPreviousDeclForInstantiation(D)) {
993 NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
996 if (!Prev) return nullptr;
997 PrevDecl = cast<EnumDecl>(Prev);
1000 EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
1001 D->getLocation(), D->getIdentifier(),
1002 PrevDecl, D->isScoped(),
1003 D->isScopedUsingClassTag(), D->isFixed());
1005 if (TypeSourceInfo *TI = D->getIntegerTypeSourceInfo()) {
1006 // If we have type source information for the underlying type, it means it
1007 // has been explicitly set by the user. Perform substitution on it before
1009 SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
1010 TypeSourceInfo *NewTI = SemaRef.SubstType(TI, TemplateArgs, UnderlyingLoc,
1012 if (!NewTI || SemaRef.CheckEnumUnderlyingType(NewTI))
1013 Enum->setIntegerType(SemaRef.Context.IntTy);
1015 Enum->setIntegerTypeSourceInfo(NewTI);
1017 assert(!D->getIntegerType()->isDependentType()
1018 && "Dependent type without type source info");
1019 Enum->setIntegerType(D->getIntegerType());
1023 SemaRef.InstantiateAttrs(TemplateArgs, D, Enum);
1025 Enum->setInstantiationOfMemberEnum(D, TSK_ImplicitInstantiation);
1026 Enum->setAccess(D->getAccess());
1027 // Forward the mangling number from the template to the instantiated decl.
1028 SemaRef.Context.setManglingNumber(Enum, SemaRef.Context.getManglingNumber(D));
1029 // See if the old tag was defined along with a declarator.
1030 // If it did, mark the new tag as being associated with that declarator.
1031 if (DeclaratorDecl *DD = SemaRef.Context.getDeclaratorForUnnamedTagDecl(D))
1032 SemaRef.Context.addDeclaratorForUnnamedTagDecl(Enum, DD);
1033 // See if the old tag was defined along with a typedef.
1034 // If it did, mark the new tag as being associated with that typedef.
1035 if (TypedefNameDecl *TND = SemaRef.Context.getTypedefNameForUnnamedTagDecl(D))
1036 SemaRef.Context.addTypedefNameForUnnamedTagDecl(Enum, TND);
1037 if (SubstQualifier(D, Enum)) return nullptr;
1038 Owner->addDecl(Enum);
1040 EnumDecl *Def = D->getDefinition();
1041 if (Def && Def != D) {
1042 // If this is an out-of-line definition of an enum member template, check
1043 // that the underlying types match in the instantiation of both
1045 if (TypeSourceInfo *TI = Def->getIntegerTypeSourceInfo()) {
1046 SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
1047 QualType DefnUnderlying =
1048 SemaRef.SubstType(TI->getType(), TemplateArgs,
1049 UnderlyingLoc, DeclarationName());
1050 SemaRef.CheckEnumRedeclaration(Def->getLocation(), Def->isScoped(),
1052 /*EnumUnderlyingIsImplicit=*/false, Enum);
1056 // C++11 [temp.inst]p1: The implicit instantiation of a class template
1057 // specialization causes the implicit instantiation of the declarations, but
1058 // not the definitions of scoped member enumerations.
1060 // DR1484 clarifies that enumeration definitions inside of a template
1061 // declaration aren't considered entities that can be separately instantiated
1062 // from the rest of the entity they are declared inside of.
1063 if (isDeclWithinFunction(D) ? D == Def : Def && !Enum->isScoped()) {
1064 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
1065 InstantiateEnumDefinition(Enum, Def);
1071 void TemplateDeclInstantiator::InstantiateEnumDefinition(
1072 EnumDecl *Enum, EnumDecl *Pattern) {
1073 Enum->startDefinition();
1075 // Update the location to refer to the definition.
1076 Enum->setLocation(Pattern->getLocation());
1078 SmallVector<Decl*, 4> Enumerators;
1080 EnumConstantDecl *LastEnumConst = nullptr;
1081 for (auto *EC : Pattern->enumerators()) {
1082 // The specified value for the enumerator.
1083 ExprResult Value((Expr *)nullptr);
1084 if (Expr *UninstValue = EC->getInitExpr()) {
1085 // The enumerator's value expression is a constant expression.
1086 EnterExpressionEvaluationContext Unevaluated(
1087 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
1089 Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
1092 // Drop the initial value and continue.
1093 bool isInvalid = false;
1094 if (Value.isInvalid()) {
1099 EnumConstantDecl *EnumConst
1100 = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
1101 EC->getLocation(), EC->getIdentifier(),
1106 EnumConst->setInvalidDecl();
1107 Enum->setInvalidDecl();
1111 SemaRef.InstantiateAttrs(TemplateArgs, EC, EnumConst);
1113 EnumConst->setAccess(Enum->getAccess());
1114 Enum->addDecl(EnumConst);
1115 Enumerators.push_back(EnumConst);
1116 LastEnumConst = EnumConst;
1118 if (Pattern->getDeclContext()->isFunctionOrMethod() &&
1119 !Enum->isScoped()) {
1120 // If the enumeration is within a function or method, record the enum
1121 // constant as a local.
1122 SemaRef.CurrentInstantiationScope->InstantiatedLocal(EC, EnumConst);
1127 SemaRef.ActOnEnumBody(Enum->getLocation(), Enum->getBraceRange(), Enum,
1132 Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
1133 llvm_unreachable("EnumConstantDecls can only occur within EnumDecls.");
1137 TemplateDeclInstantiator::VisitBuiltinTemplateDecl(BuiltinTemplateDecl *D) {
1138 llvm_unreachable("BuiltinTemplateDecls cannot be instantiated.");
1141 Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1142 bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1144 // Create a local instantiation scope for this class template, which
1145 // will contain the instantiations of the template parameters.
1146 LocalInstantiationScope Scope(SemaRef);
1147 TemplateParameterList *TempParams = D->getTemplateParameters();
1148 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1152 CXXRecordDecl *Pattern = D->getTemplatedDecl();
1154 // Instantiate the qualifier. We have to do this first in case
1155 // we're a friend declaration, because if we are then we need to put
1156 // the new declaration in the appropriate context.
1157 NestedNameSpecifierLoc QualifierLoc = Pattern->getQualifierLoc();
1159 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1165 CXXRecordDecl *PrevDecl = nullptr;
1166 ClassTemplateDecl *PrevClassTemplate = nullptr;
1168 if (!isFriend && getPreviousDeclForInstantiation(Pattern)) {
1169 DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
1170 if (!Found.empty()) {
1171 PrevClassTemplate = dyn_cast<ClassTemplateDecl>(Found.front());
1172 if (PrevClassTemplate)
1173 PrevDecl = PrevClassTemplate->getTemplatedDecl();
1177 // If this isn't a friend, then it's a member template, in which
1178 // case we just want to build the instantiation in the
1179 // specialization. If it is a friend, we want to build it in
1180 // the appropriate context.
1181 DeclContext *DC = Owner;
1185 SS.Adopt(QualifierLoc);
1186 DC = SemaRef.computeDeclContext(SS);
1187 if (!DC) return nullptr;
1189 DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
1190 Pattern->getDeclContext(),
1194 // Look for a previous declaration of the template in the owning
1196 LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
1197 Sema::LookupOrdinaryName, Sema::ForRedeclaration);
1198 SemaRef.LookupQualifiedName(R, DC);
1200 if (R.isSingleResult()) {
1201 PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
1202 if (PrevClassTemplate)
1203 PrevDecl = PrevClassTemplate->getTemplatedDecl();
1206 if (!PrevClassTemplate && QualifierLoc) {
1207 SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
1208 << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
1209 << QualifierLoc.getSourceRange();
1213 bool AdoptedPreviousTemplateParams = false;
1214 if (PrevClassTemplate) {
1215 bool Complain = true;
1217 // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
1218 // template for struct std::tr1::__detail::_Map_base, where the
1219 // template parameters of the friend declaration don't match the
1220 // template parameters of the original declaration. In this one
1221 // case, we don't complain about the ill-formed friend
1223 if (isFriend && Pattern->getIdentifier() &&
1224 Pattern->getIdentifier()->isStr("_Map_base") &&
1225 DC->isNamespace() &&
1226 cast<NamespaceDecl>(DC)->getIdentifier() &&
1227 cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
1228 DeclContext *DCParent = DC->getParent();
1229 if (DCParent->isNamespace() &&
1230 cast<NamespaceDecl>(DCParent)->getIdentifier() &&
1231 cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
1232 if (cast<Decl>(DCParent)->isInStdNamespace())
1237 TemplateParameterList *PrevParams
1238 = PrevClassTemplate->getTemplateParameters();
1240 // Make sure the parameter lists match.
1241 if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
1243 Sema::TPL_TemplateMatch)) {
1247 AdoptedPreviousTemplateParams = true;
1248 InstParams = PrevParams;
1251 // Do some additional validation, then merge default arguments
1252 // from the existing declarations.
1253 if (!AdoptedPreviousTemplateParams &&
1254 SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
1255 Sema::TPC_ClassTemplate))
1260 CXXRecordDecl *RecordInst
1261 = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
1262 Pattern->getLocStart(), Pattern->getLocation(),
1263 Pattern->getIdentifier(), PrevDecl,
1264 /*DelayTypeCreation=*/true);
1267 RecordInst->setQualifierInfo(QualifierLoc);
1269 ClassTemplateDecl *Inst
1270 = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
1271 D->getIdentifier(), InstParams, RecordInst);
1272 assert(!(isFriend && Owner->isDependentContext()));
1273 Inst->setPreviousDecl(PrevClassTemplate);
1275 RecordInst->setDescribedClassTemplate(Inst);
1278 if (PrevClassTemplate)
1279 Inst->setAccess(PrevClassTemplate->getAccess());
1281 Inst->setAccess(D->getAccess());
1283 Inst->setObjectOfFriendDecl();
1284 // TODO: do we want to track the instantiation progeny of this
1285 // friend target decl?
1287 Inst->setAccess(D->getAccess());
1288 if (!PrevClassTemplate)
1289 Inst->setInstantiatedFromMemberTemplate(D);
1292 // Trigger creation of the type for the instantiation.
1293 SemaRef.Context.getInjectedClassNameType(RecordInst,
1294 Inst->getInjectedClassNameSpecialization());
1296 // Finish handling of friends.
1298 DC->makeDeclVisibleInContext(Inst);
1299 Inst->setLexicalDeclContext(Owner);
1300 RecordInst->setLexicalDeclContext(Owner);
1304 if (D->isOutOfLine()) {
1305 Inst->setLexicalDeclContext(D->getLexicalDeclContext());
1306 RecordInst->setLexicalDeclContext(D->getLexicalDeclContext());
1309 Owner->addDecl(Inst);
1311 if (!PrevClassTemplate) {
1312 // Queue up any out-of-line partial specializations of this member
1313 // class template; the client will force their instantiation once
1314 // the enclosing class has been instantiated.
1315 SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
1316 D->getPartialSpecializations(PartialSpecs);
1317 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
1318 if (PartialSpecs[I]->getFirstDecl()->isOutOfLine())
1319 OutOfLinePartialSpecs.push_back(std::make_pair(Inst, PartialSpecs[I]));
1326 TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
1327 ClassTemplatePartialSpecializationDecl *D) {
1328 ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
1330 // Lookup the already-instantiated declaration in the instantiation
1331 // of the class template and return that.
1332 DeclContext::lookup_result Found
1333 = Owner->lookup(ClassTemplate->getDeclName());
1337 ClassTemplateDecl *InstClassTemplate
1338 = dyn_cast<ClassTemplateDecl>(Found.front());
1339 if (!InstClassTemplate)
1342 if (ClassTemplatePartialSpecializationDecl *Result
1343 = InstClassTemplate->findPartialSpecInstantiatedFromMember(D))
1346 return InstantiateClassTemplatePartialSpecialization(InstClassTemplate, D);
1349 Decl *TemplateDeclInstantiator::VisitVarTemplateDecl(VarTemplateDecl *D) {
1350 assert(D->getTemplatedDecl()->isStaticDataMember() &&
1351 "Only static data member templates are allowed.");
1353 // Create a local instantiation scope for this variable template, which
1354 // will contain the instantiations of the template parameters.
1355 LocalInstantiationScope Scope(SemaRef);
1356 TemplateParameterList *TempParams = D->getTemplateParameters();
1357 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1361 VarDecl *Pattern = D->getTemplatedDecl();
1362 VarTemplateDecl *PrevVarTemplate = nullptr;
1364 if (getPreviousDeclForInstantiation(Pattern)) {
1365 DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
1367 PrevVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
1371 cast_or_null<VarDecl>(VisitVarDecl(Pattern,
1372 /*InstantiatingVarTemplate=*/true));
1373 if (!VarInst) return nullptr;
1375 DeclContext *DC = Owner;
1377 VarTemplateDecl *Inst = VarTemplateDecl::Create(
1378 SemaRef.Context, DC, D->getLocation(), D->getIdentifier(), InstParams,
1380 VarInst->setDescribedVarTemplate(Inst);
1381 Inst->setPreviousDecl(PrevVarTemplate);
1383 Inst->setAccess(D->getAccess());
1384 if (!PrevVarTemplate)
1385 Inst->setInstantiatedFromMemberTemplate(D);
1387 if (D->isOutOfLine()) {
1388 Inst->setLexicalDeclContext(D->getLexicalDeclContext());
1389 VarInst->setLexicalDeclContext(D->getLexicalDeclContext());
1392 Owner->addDecl(Inst);
1394 if (!PrevVarTemplate) {
1395 // Queue up any out-of-line partial specializations of this member
1396 // variable template; the client will force their instantiation once
1397 // the enclosing class has been instantiated.
1398 SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
1399 D->getPartialSpecializations(PartialSpecs);
1400 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
1401 if (PartialSpecs[I]->getFirstDecl()->isOutOfLine())
1402 OutOfLineVarPartialSpecs.push_back(
1403 std::make_pair(Inst, PartialSpecs[I]));
1409 Decl *TemplateDeclInstantiator::VisitVarTemplatePartialSpecializationDecl(
1410 VarTemplatePartialSpecializationDecl *D) {
1411 assert(D->isStaticDataMember() &&
1412 "Only static data member templates are allowed.");
1414 VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
1416 // Lookup the already-instantiated declaration and return that.
1417 DeclContext::lookup_result Found = Owner->lookup(VarTemplate->getDeclName());
1418 assert(!Found.empty() && "Instantiation found nothing?");
1420 VarTemplateDecl *InstVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
1421 assert(InstVarTemplate && "Instantiation did not find a variable template?");
1423 if (VarTemplatePartialSpecializationDecl *Result =
1424 InstVarTemplate->findPartialSpecInstantiatedFromMember(D))
1427 return InstantiateVarTemplatePartialSpecialization(InstVarTemplate, D);
1431 TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1432 // Create a local instantiation scope for this function template, which
1433 // will contain the instantiations of the template parameters and then get
1434 // merged with the local instantiation scope for the function template
1436 LocalInstantiationScope Scope(SemaRef);
1438 TemplateParameterList *TempParams = D->getTemplateParameters();
1439 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1443 FunctionDecl *Instantiated = nullptr;
1444 if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
1445 Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
1448 Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
1449 D->getTemplatedDecl(),
1455 // Link the instantiated function template declaration to the function
1456 // template from which it was instantiated.
1457 FunctionTemplateDecl *InstTemplate
1458 = Instantiated->getDescribedFunctionTemplate();
1459 InstTemplate->setAccess(D->getAccess());
1460 assert(InstTemplate &&
1461 "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
1463 bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
1465 // Link the instantiation back to the pattern *unless* this is a
1466 // non-definition friend declaration.
1467 if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
1468 !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
1469 InstTemplate->setInstantiatedFromMemberTemplate(D);
1471 // Make declarations visible in the appropriate context.
1473 Owner->addDecl(InstTemplate);
1474 } else if (InstTemplate->getDeclContext()->isRecord() &&
1475 !getPreviousDeclForInstantiation(D)) {
1476 SemaRef.CheckFriendAccess(InstTemplate);
1479 return InstTemplate;
1482 Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
1483 CXXRecordDecl *PrevDecl = nullptr;
1484 if (D->isInjectedClassName())
1485 PrevDecl = cast<CXXRecordDecl>(Owner);
1486 else if (CXXRecordDecl *PatternPrev = getPreviousDeclForInstantiation(D)) {
1487 NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
1490 if (!Prev) return nullptr;
1491 PrevDecl = cast<CXXRecordDecl>(Prev);
1494 CXXRecordDecl *Record
1495 = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
1496 D->getLocStart(), D->getLocation(),
1497 D->getIdentifier(), PrevDecl);
1499 // Substitute the nested name specifier, if any.
1500 if (SubstQualifier(D, Record))
1503 Record->setImplicit(D->isImplicit());
1504 // FIXME: Check against AS_none is an ugly hack to work around the issue that
1505 // the tag decls introduced by friend class declarations don't have an access
1506 // specifier. Remove once this area of the code gets sorted out.
1507 if (D->getAccess() != AS_none)
1508 Record->setAccess(D->getAccess());
1509 if (!D->isInjectedClassName())
1510 Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
1512 // If the original function was part of a friend declaration,
1513 // inherit its namespace state.
1514 if (D->getFriendObjectKind())
1515 Record->setObjectOfFriendDecl();
1517 // Make sure that anonymous structs and unions are recorded.
1518 if (D->isAnonymousStructOrUnion())
1519 Record->setAnonymousStructOrUnion(true);
1521 if (D->isLocalClass())
1522 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
1524 // Forward the mangling number from the template to the instantiated decl.
1525 SemaRef.Context.setManglingNumber(Record,
1526 SemaRef.Context.getManglingNumber(D));
1528 // See if the old tag was defined along with a declarator.
1529 // If it did, mark the new tag as being associated with that declarator.
1530 if (DeclaratorDecl *DD = SemaRef.Context.getDeclaratorForUnnamedTagDecl(D))
1531 SemaRef.Context.addDeclaratorForUnnamedTagDecl(Record, DD);
1533 // See if the old tag was defined along with a typedef.
1534 // If it did, mark the new tag as being associated with that typedef.
1535 if (TypedefNameDecl *TND = SemaRef.Context.getTypedefNameForUnnamedTagDecl(D))
1536 SemaRef.Context.addTypedefNameForUnnamedTagDecl(Record, TND);
1538 Owner->addDecl(Record);
1540 // DR1484 clarifies that the members of a local class are instantiated as part
1541 // of the instantiation of their enclosing entity.
1542 if (D->isCompleteDefinition() && D->isLocalClass()) {
1543 Sema::LocalEagerInstantiationScope LocalInstantiations(SemaRef);
1545 SemaRef.InstantiateClass(D->getLocation(), Record, D, TemplateArgs,
1546 TSK_ImplicitInstantiation,
1549 // For nested local classes, we will instantiate the members when we
1550 // reach the end of the outermost (non-nested) local class.
1551 if (!D->isCXXClassMember())
1552 SemaRef.InstantiateClassMembers(D->getLocation(), Record, TemplateArgs,
1553 TSK_ImplicitInstantiation);
1555 // This class may have local implicit instantiations that need to be
1556 // performed within this scope.
1557 LocalInstantiations.perform();
1560 SemaRef.DiagnoseUnusedNestedTypedefs(Record);
1565 /// \brief Adjust the given function type for an instantiation of the
1566 /// given declaration, to cope with modifications to the function's type that
1567 /// aren't reflected in the type-source information.
1569 /// \param D The declaration we're instantiating.
1570 /// \param TInfo The already-instantiated type.
1571 static QualType adjustFunctionTypeForInstantiation(ASTContext &Context,
1573 TypeSourceInfo *TInfo) {
1574 const FunctionProtoType *OrigFunc
1575 = D->getType()->castAs<FunctionProtoType>();
1576 const FunctionProtoType *NewFunc
1577 = TInfo->getType()->castAs<FunctionProtoType>();
1578 if (OrigFunc->getExtInfo() == NewFunc->getExtInfo())
1579 return TInfo->getType();
1581 FunctionProtoType::ExtProtoInfo NewEPI = NewFunc->getExtProtoInfo();
1582 NewEPI.ExtInfo = OrigFunc->getExtInfo();
1583 return Context.getFunctionType(NewFunc->getReturnType(),
1584 NewFunc->getParamTypes(), NewEPI);
1587 /// Normal class members are of more specific types and therefore
1588 /// don't make it here. This function serves two purposes:
1589 /// 1) instantiating function templates
1590 /// 2) substituting friend declarations
1591 Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
1592 TemplateParameterList *TemplateParams) {
1593 // Check whether there is already a function template specialization for
1594 // this declaration.
1595 FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1596 if (FunctionTemplate && !TemplateParams) {
1597 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1599 void *InsertPos = nullptr;
1600 FunctionDecl *SpecFunc
1601 = FunctionTemplate->findSpecialization(Innermost, InsertPos);
1603 // If we already have a function template specialization, return it.
1609 if (FunctionTemplate)
1610 isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1612 isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1614 bool MergeWithParentScope = (TemplateParams != nullptr) ||
1615 Owner->isFunctionOrMethod() ||
1616 !(isa<Decl>(Owner) &&
1617 cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1618 LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1620 SmallVector<ParmVarDecl *, 4> Params;
1621 TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
1624 QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
1626 NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1628 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1634 // If we're instantiating a local function declaration, put the result
1635 // in the enclosing namespace; otherwise we need to find the instantiated
1638 if (D->isLocalExternDecl()) {
1640 SemaRef.adjustContextForLocalExternDecl(DC);
1641 } else if (isFriend && QualifierLoc) {
1643 SS.Adopt(QualifierLoc);
1644 DC = SemaRef.computeDeclContext(SS);
1645 if (!DC) return nullptr;
1647 DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1651 FunctionDecl *Function;
1652 if (auto *DGuide = dyn_cast<CXXDeductionGuideDecl>(D))
1653 Function = CXXDeductionGuideDecl::Create(
1654 SemaRef.Context, DC, D->getInnerLocStart(), DGuide->isExplicit(),
1655 D->getNameInfo(), T, TInfo, D->getSourceRange().getEnd());
1657 Function = FunctionDecl::Create(
1658 SemaRef.Context, DC, D->getInnerLocStart(), D->getNameInfo(), T, TInfo,
1659 D->getCanonicalDecl()->getStorageClass(), D->isInlineSpecified(),
1660 D->hasWrittenPrototype(), D->isConstexpr());
1661 Function->setRangeEnd(D->getSourceRange().getEnd());
1665 Function->setImplicitlyInline();
1668 Function->setQualifierInfo(QualifierLoc);
1670 if (D->isLocalExternDecl())
1671 Function->setLocalExternDecl();
1673 DeclContext *LexicalDC = Owner;
1674 if (!isFriend && D->isOutOfLine() && !D->isLocalExternDecl()) {
1675 assert(D->getDeclContext()->isFileContext());
1676 LexicalDC = D->getDeclContext();
1679 Function->setLexicalDeclContext(LexicalDC);
1681 // Attach the parameters
1682 for (unsigned P = 0; P < Params.size(); ++P)
1684 Params[P]->setOwningFunction(Function);
1685 Function->setParams(Params);
1687 SourceLocation InstantiateAtPOI;
1688 if (TemplateParams) {
1689 // Our resulting instantiation is actually a function template, since we
1690 // are substituting only the outer template parameters. For example, given
1692 // template<typename T>
1694 // template<typename U> friend void f(T, U);
1699 // We are instantiating the friend function template "f" within X<int>,
1700 // which means substituting int for T, but leaving "f" as a friend function
1702 // Build the function template itself.
1703 FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1704 Function->getLocation(),
1705 Function->getDeclName(),
1706 TemplateParams, Function);
1707 Function->setDescribedFunctionTemplate(FunctionTemplate);
1709 FunctionTemplate->setLexicalDeclContext(LexicalDC);
1711 if (isFriend && D->isThisDeclarationADefinition()) {
1712 FunctionTemplate->setInstantiatedFromMemberTemplate(
1713 D->getDescribedFunctionTemplate());
1715 } else if (FunctionTemplate) {
1716 // Record this function template specialization.
1717 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1718 Function->setFunctionTemplateSpecialization(FunctionTemplate,
1719 TemplateArgumentList::CreateCopy(SemaRef.Context,
1721 /*InsertPos=*/nullptr);
1722 } else if (isFriend && D->isThisDeclarationADefinition()) {
1723 // Do not connect the friend to the template unless it's actually a
1724 // definition. We don't want non-template functions to be marked as being
1725 // template instantiations.
1726 Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1729 if (InitFunctionInstantiation(Function, D))
1730 Function->setInvalidDecl();
1732 bool isExplicitSpecialization = false;
1734 LookupResult Previous(
1735 SemaRef, Function->getDeclName(), SourceLocation(),
1736 D->isLocalExternDecl() ? Sema::LookupRedeclarationWithLinkage
1737 : Sema::LookupOrdinaryName,
1738 Sema::ForRedeclaration);
1740 if (DependentFunctionTemplateSpecializationInfo *Info
1741 = D->getDependentSpecializationInfo()) {
1742 assert(isFriend && "non-friend has dependent specialization info?");
1744 // This needs to be set now for future sanity.
1745 Function->setObjectOfFriendDecl();
1747 // Instantiate the explicit template arguments.
1748 TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1749 Info->getRAngleLoc());
1750 if (SemaRef.Subst(Info->getTemplateArgs(), Info->getNumTemplateArgs(),
1751 ExplicitArgs, TemplateArgs))
1754 // Map the candidate templates to their instantiations.
1755 for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1756 Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1757 Info->getTemplate(I),
1759 if (!Temp) return nullptr;
1761 Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1764 if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1767 Function->setInvalidDecl();
1769 isExplicitSpecialization = true;
1771 } else if (TemplateParams || !FunctionTemplate) {
1772 // Look only into the namespace where the friend would be declared to
1773 // find a previous declaration. This is the innermost enclosing namespace,
1774 // as described in ActOnFriendFunctionDecl.
1775 SemaRef.LookupQualifiedName(Previous, DC);
1777 // In C++, the previous declaration we find might be a tag type
1778 // (class or enum). In this case, the new declaration will hide the
1779 // tag type. Note that this does does not apply if we're declaring a
1780 // typedef (C++ [dcl.typedef]p4).
1781 if (Previous.isSingleTagDecl())
1786 Function->setObjectOfFriendDecl();
1788 SemaRef.CheckFunctionDeclaration(/*Scope*/ nullptr, Function, Previous,
1789 isExplicitSpecialization);
1791 NamedDecl *PrincipalDecl = (TemplateParams
1792 ? cast<NamedDecl>(FunctionTemplate)
1795 // If the original function was part of a friend declaration,
1796 // inherit its namespace state and add it to the owner.
1798 PrincipalDecl->setObjectOfFriendDecl();
1799 DC->makeDeclVisibleInContext(PrincipalDecl);
1801 bool QueuedInstantiation = false;
1803 // C++11 [temp.friend]p4 (DR329):
1804 // When a function is defined in a friend function declaration in a class
1805 // template, the function is instantiated when the function is odr-used.
1806 // The same restrictions on multiple declarations and definitions that
1807 // apply to non-template function declarations and definitions also apply
1808 // to these implicit definitions.
1809 if (D->isThisDeclarationADefinition()) {
1810 // Check for a function body.
1811 const FunctionDecl *Definition = nullptr;
1812 if (Function->isDefined(Definition) &&
1813 Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1814 SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1815 << Function->getDeclName();
1816 SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1818 // Check for redefinitions due to other instantiations of this or
1819 // a similar friend function.
1820 else for (auto R : Function->redecls()) {
1824 // If some prior declaration of this function has been used, we need
1825 // to instantiate its definition.
1826 if (!QueuedInstantiation && R->isUsed(false)) {
1827 if (MemberSpecializationInfo *MSInfo =
1828 Function->getMemberSpecializationInfo()) {
1829 if (MSInfo->getPointOfInstantiation().isInvalid()) {
1830 SourceLocation Loc = R->getLocation(); // FIXME
1831 MSInfo->setPointOfInstantiation(Loc);
1832 SemaRef.PendingLocalImplicitInstantiations.push_back(
1833 std::make_pair(Function, Loc));
1834 QueuedInstantiation = true;
1839 // If some prior declaration of this function was a friend with an
1840 // uninstantiated definition, reject it.
1841 if (R->getFriendObjectKind()) {
1842 if (const FunctionDecl *RPattern =
1843 R->getTemplateInstantiationPattern()) {
1844 if (RPattern->isDefined(RPattern)) {
1845 SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1846 << Function->getDeclName();
1847 SemaRef.Diag(R->getLocation(), diag::note_previous_definition);
1855 // Check the template parameter list against the previous declaration. The
1856 // goal here is to pick up default arguments added since the friend was
1857 // declared; we know the template parameter lists match, since otherwise
1858 // we would not have picked this template as the previous declaration.
1859 if (TemplateParams && FunctionTemplate->getPreviousDecl()) {
1860 SemaRef.CheckTemplateParameterList(
1862 FunctionTemplate->getPreviousDecl()->getTemplateParameters(),
1863 Function->isThisDeclarationADefinition()
1864 ? Sema::TPC_FriendFunctionTemplateDefinition
1865 : Sema::TPC_FriendFunctionTemplate);
1869 if (Function->isLocalExternDecl() && !Function->getPreviousDecl())
1870 DC->makeDeclVisibleInContext(PrincipalDecl);
1872 if (Function->isOverloadedOperator() && !DC->isRecord() &&
1873 PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1874 PrincipalDecl->setNonMemberOperator();
1876 assert(!D->isDefaulted() && "only methods should be defaulted");
1881 TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1882 TemplateParameterList *TemplateParams,
1883 bool IsClassScopeSpecialization) {
1884 FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1885 if (FunctionTemplate && !TemplateParams) {
1886 // We are creating a function template specialization from a function
1887 // template. Check whether there is already a function template
1888 // specialization for this particular set of template arguments.
1889 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1891 void *InsertPos = nullptr;
1892 FunctionDecl *SpecFunc
1893 = FunctionTemplate->findSpecialization(Innermost, InsertPos);
1895 // If we already have a function template specialization, return it.
1901 if (FunctionTemplate)
1902 isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1904 isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1906 bool MergeWithParentScope = (TemplateParams != nullptr) ||
1907 !(isa<Decl>(Owner) &&
1908 cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1909 LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1911 // Instantiate enclosing template arguments for friends.
1912 SmallVector<TemplateParameterList *, 4> TempParamLists;
1913 unsigned NumTempParamLists = 0;
1914 if (isFriend && (NumTempParamLists = D->getNumTemplateParameterLists())) {
1915 TempParamLists.resize(NumTempParamLists);
1916 for (unsigned I = 0; I != NumTempParamLists; ++I) {
1917 TemplateParameterList *TempParams = D->getTemplateParameterList(I);
1918 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1921 TempParamLists[I] = InstParams;
1925 SmallVector<ParmVarDecl *, 4> Params;
1926 TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
1929 QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
1931 NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1933 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1939 DeclContext *DC = Owner;
1943 SS.Adopt(QualifierLoc);
1944 DC = SemaRef.computeDeclContext(SS);
1946 if (DC && SemaRef.RequireCompleteDeclContext(SS, DC))
1949 DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1950 D->getDeclContext(),
1953 if (!DC) return nullptr;
1956 // Build the instantiated method declaration.
1957 CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1958 CXXMethodDecl *Method = nullptr;
1960 SourceLocation StartLoc = D->getInnerLocStart();
1961 DeclarationNameInfo NameInfo
1962 = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1963 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1964 Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1965 StartLoc, NameInfo, T, TInfo,
1966 Constructor->isExplicit(),
1967 Constructor->isInlineSpecified(),
1968 false, Constructor->isConstexpr());
1969 Method->setRangeEnd(Constructor->getLocEnd());
1970 } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1971 Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1972 StartLoc, NameInfo, T, TInfo,
1973 Destructor->isInlineSpecified(),
1975 Method->setRangeEnd(Destructor->getLocEnd());
1976 } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1977 Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1978 StartLoc, NameInfo, T, TInfo,
1979 Conversion->isInlineSpecified(),
1980 Conversion->isExplicit(),
1981 Conversion->isConstexpr(),
1982 Conversion->getLocEnd());
1984 StorageClass SC = D->isStatic() ? SC_Static : SC_None;
1985 Method = CXXMethodDecl::Create(SemaRef.Context, Record,
1986 StartLoc, NameInfo, T, TInfo,
1987 SC, D->isInlineSpecified(),
1988 D->isConstexpr(), D->getLocEnd());
1992 Method->setImplicitlyInline();
1995 Method->setQualifierInfo(QualifierLoc);
1997 if (TemplateParams) {
1998 // Our resulting instantiation is actually a function template, since we
1999 // are substituting only the outer template parameters. For example, given
2001 // template<typename T>
2003 // template<typename U> void f(T, U);
2008 // We are instantiating the member template "f" within X<int>, which means
2009 // substituting int for T, but leaving "f" as a member function template.
2010 // Build the function template itself.
2011 FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
2012 Method->getLocation(),
2013 Method->getDeclName(),
2014 TemplateParams, Method);
2016 FunctionTemplate->setLexicalDeclContext(Owner);
2017 FunctionTemplate->setObjectOfFriendDecl();
2018 } else if (D->isOutOfLine())
2019 FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
2020 Method->setDescribedFunctionTemplate(FunctionTemplate);
2021 } else if (FunctionTemplate) {
2022 // Record this function template specialization.
2023 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
2024 Method->setFunctionTemplateSpecialization(FunctionTemplate,
2025 TemplateArgumentList::CreateCopy(SemaRef.Context,
2027 /*InsertPos=*/nullptr);
2028 } else if (!isFriend) {
2029 // Record that this is an instantiation of a member function.
2030 Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
2033 // If we are instantiating a member function defined
2034 // out-of-line, the instantiation will have the same lexical
2035 // context (which will be a namespace scope) as the template.
2037 if (NumTempParamLists)
2038 Method->setTemplateParameterListsInfo(
2040 llvm::makeArrayRef(TempParamLists.data(), NumTempParamLists));
2042 Method->setLexicalDeclContext(Owner);
2043 Method->setObjectOfFriendDecl();
2044 } else if (D->isOutOfLine())
2045 Method->setLexicalDeclContext(D->getLexicalDeclContext());
2047 // Attach the parameters
2048 for (unsigned P = 0; P < Params.size(); ++P)
2049 Params[P]->setOwningFunction(Method);
2050 Method->setParams(Params);
2052 if (InitMethodInstantiation(Method, D))
2053 Method->setInvalidDecl();
2055 LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
2056 Sema::ForRedeclaration);
2058 if (!FunctionTemplate || TemplateParams || isFriend) {
2059 SemaRef.LookupQualifiedName(Previous, Record);
2061 // In C++, the previous declaration we find might be a tag type
2062 // (class or enum). In this case, the new declaration will hide the
2063 // tag type. Note that this does does not apply if we're declaring a
2064 // typedef (C++ [dcl.typedef]p4).
2065 if (Previous.isSingleTagDecl())
2069 if (!IsClassScopeSpecialization)
2070 SemaRef.CheckFunctionDeclaration(nullptr, Method, Previous, false);
2073 SemaRef.CheckPureMethod(Method, SourceRange());
2075 // Propagate access. For a non-friend declaration, the access is
2076 // whatever we're propagating from. For a friend, it should be the
2077 // previous declaration we just found.
2078 if (isFriend && Method->getPreviousDecl())
2079 Method->setAccess(Method->getPreviousDecl()->getAccess());
2081 Method->setAccess(D->getAccess());
2082 if (FunctionTemplate)
2083 FunctionTemplate->setAccess(Method->getAccess());
2085 SemaRef.CheckOverrideControl(Method);
2087 // If a function is defined as defaulted or deleted, mark it as such now.
2088 if (D->isExplicitlyDefaulted())
2089 SemaRef.SetDeclDefaulted(Method, Method->getLocation());
2090 if (D->isDeletedAsWritten())
2091 SemaRef.SetDeclDeleted(Method, Method->getLocation());
2093 // If there's a function template, let our caller handle it.
2094 if (FunctionTemplate) {
2097 // Don't hide a (potentially) valid declaration with an invalid one.
2098 } else if (Method->isInvalidDecl() && !Previous.empty()) {
2101 // Otherwise, check access to friends and make them visible.
2102 } else if (isFriend) {
2103 // We only need to re-check access for methods which we didn't
2104 // manage to match during parsing.
2105 if (!D->getPreviousDecl())
2106 SemaRef.CheckFriendAccess(Method);
2108 Record->makeDeclVisibleInContext(Method);
2110 // Otherwise, add the declaration. We don't need to do this for
2111 // class-scope specializations because we'll have matched them with
2112 // the appropriate template.
2113 } else if (!IsClassScopeSpecialization) {
2114 Owner->addDecl(Method);
2120 Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
2121 return VisitCXXMethodDecl(D);
2124 Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
2125 return VisitCXXMethodDecl(D);
2128 Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
2129 return VisitCXXMethodDecl(D);
2132 Decl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
2133 return SemaRef.SubstParmVarDecl(D, TemplateArgs, /*indexAdjustment*/ 0, None,
2134 /*ExpectParameterPack=*/ false);
2137 Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
2138 TemplateTypeParmDecl *D) {
2139 // TODO: don't always clone when decls are refcounted.
2140 assert(D->getTypeForDecl()->isTemplateTypeParmType());
2142 TemplateTypeParmDecl *Inst = TemplateTypeParmDecl::Create(
2143 SemaRef.Context, Owner, D->getLocStart(), D->getLocation(),
2144 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(), D->getIndex(),
2145 D->getIdentifier(), D->wasDeclaredWithTypename(), D->isParameterPack());
2146 Inst->setAccess(AS_public);
2148 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2149 TypeSourceInfo *InstantiatedDefaultArg =
2150 SemaRef.SubstType(D->getDefaultArgumentInfo(), TemplateArgs,
2151 D->getDefaultArgumentLoc(), D->getDeclName());
2152 if (InstantiatedDefaultArg)
2153 Inst->setDefaultArgument(InstantiatedDefaultArg);
2156 // Introduce this template parameter's instantiation into the instantiation
2158 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
2163 Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
2164 NonTypeTemplateParmDecl *D) {
2165 // Substitute into the type of the non-type template parameter.
2166 TypeLoc TL = D->getTypeSourceInfo()->getTypeLoc();
2167 SmallVector<TypeSourceInfo *, 4> ExpandedParameterPackTypesAsWritten;
2168 SmallVector<QualType, 4> ExpandedParameterPackTypes;
2169 bool IsExpandedParameterPack = false;
2172 bool Invalid = false;
2174 if (D->isExpandedParameterPack()) {
2175 // The non-type template parameter pack is an already-expanded pack
2176 // expansion of types. Substitute into each of the expanded types.
2177 ExpandedParameterPackTypes.reserve(D->getNumExpansionTypes());
2178 ExpandedParameterPackTypesAsWritten.reserve(D->getNumExpansionTypes());
2179 for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
2180 TypeSourceInfo *NewDI =
2181 SemaRef.SubstType(D->getExpansionTypeSourceInfo(I), TemplateArgs,
2182 D->getLocation(), D->getDeclName());
2187 SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
2191 ExpandedParameterPackTypesAsWritten.push_back(NewDI);
2192 ExpandedParameterPackTypes.push_back(NewT);
2195 IsExpandedParameterPack = true;
2196 DI = D->getTypeSourceInfo();
2198 } else if (D->isPackExpansion()) {
2199 // The non-type template parameter pack's type is a pack expansion of types.
2200 // Determine whether we need to expand this parameter pack into separate
2202 PackExpansionTypeLoc Expansion = TL.castAs<PackExpansionTypeLoc>();
2203 TypeLoc Pattern = Expansion.getPatternLoc();
2204 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2205 SemaRef.collectUnexpandedParameterPacks(Pattern, Unexpanded);
2207 // Determine whether the set of unexpanded parameter packs can and should
2210 bool RetainExpansion = false;
2211 Optional<unsigned> OrigNumExpansions
2212 = Expansion.getTypePtr()->getNumExpansions();
2213 Optional<unsigned> NumExpansions = OrigNumExpansions;
2214 if (SemaRef.CheckParameterPacksForExpansion(Expansion.getEllipsisLoc(),
2215 Pattern.getSourceRange(),
2218 Expand, RetainExpansion,
2223 for (unsigned I = 0; I != *NumExpansions; ++I) {
2224 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2225 TypeSourceInfo *NewDI = SemaRef.SubstType(Pattern, TemplateArgs,
2232 SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
2236 ExpandedParameterPackTypesAsWritten.push_back(NewDI);
2237 ExpandedParameterPackTypes.push_back(NewT);
2240 // Note that we have an expanded parameter pack. The "type" of this
2241 // expanded parameter pack is the original expansion type, but callers
2242 // will end up using the expanded parameter pack types for type-checking.
2243 IsExpandedParameterPack = true;
2244 DI = D->getTypeSourceInfo();
2247 // We cannot fully expand the pack expansion now, so substitute into the
2248 // pattern and create a new pack expansion type.
2249 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2250 TypeSourceInfo *NewPattern = SemaRef.SubstType(Pattern, TemplateArgs,
2256 SemaRef.CheckNonTypeTemplateParameterType(NewPattern, D->getLocation());
2257 DI = SemaRef.CheckPackExpansion(NewPattern, Expansion.getEllipsisLoc(),
2265 // Simple case: substitution into a parameter that is not a parameter pack.
2266 DI = SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
2267 D->getLocation(), D->getDeclName());
2271 // Check that this type is acceptable for a non-type template parameter.
2272 T = SemaRef.CheckNonTypeTemplateParameterType(DI, D->getLocation());
2274 T = SemaRef.Context.IntTy;
2279 NonTypeTemplateParmDecl *Param;
2280 if (IsExpandedParameterPack)
2281 Param = NonTypeTemplateParmDecl::Create(
2282 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
2283 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2284 D->getPosition(), D->getIdentifier(), T, DI, ExpandedParameterPackTypes,
2285 ExpandedParameterPackTypesAsWritten);
2287 Param = NonTypeTemplateParmDecl::Create(
2288 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
2289 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2290 D->getPosition(), D->getIdentifier(), T, D->isParameterPack(), DI);
2292 Param->setAccess(AS_public);
2294 Param->setInvalidDecl();
2296 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2297 EnterExpressionEvaluationContext ConstantEvaluated(
2298 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
2299 ExprResult Value = SemaRef.SubstExpr(D->getDefaultArgument(), TemplateArgs);
2300 if (!Value.isInvalid())
2301 Param->setDefaultArgument(Value.get());
2304 // Introduce this template parameter's instantiation into the instantiation
2306 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
2310 static void collectUnexpandedParameterPacks(
2312 TemplateParameterList *Params,
2313 SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) {
2314 for (const auto &P : *Params) {
2315 if (P->isTemplateParameterPack())
2317 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P))
2318 S.collectUnexpandedParameterPacks(NTTP->getTypeSourceInfo()->getTypeLoc(),
2320 if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(P))
2321 collectUnexpandedParameterPacks(S, TTP->getTemplateParameters(),
2327 TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
2328 TemplateTemplateParmDecl *D) {
2329 // Instantiate the template parameter list of the template template parameter.
2330 TemplateParameterList *TempParams = D->getTemplateParameters();
2331 TemplateParameterList *InstParams;
2332 SmallVector<TemplateParameterList*, 8> ExpandedParams;
2334 bool IsExpandedParameterPack = false;
2336 if (D->isExpandedParameterPack()) {
2337 // The template template parameter pack is an already-expanded pack
2338 // expansion of template parameters. Substitute into each of the expanded
2340 ExpandedParams.reserve(D->getNumExpansionTemplateParameters());
2341 for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
2343 LocalInstantiationScope Scope(SemaRef);
2344 TemplateParameterList *Expansion =
2345 SubstTemplateParams(D->getExpansionTemplateParameters(I));
2348 ExpandedParams.push_back(Expansion);
2351 IsExpandedParameterPack = true;
2352 InstParams = TempParams;
2353 } else if (D->isPackExpansion()) {
2354 // The template template parameter pack expands to a pack of template
2355 // template parameters. Determine whether we need to expand this parameter
2356 // pack into separate parameters.
2357 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2358 collectUnexpandedParameterPacks(SemaRef, D->getTemplateParameters(),
2361 // Determine whether the set of unexpanded parameter packs can and should
2364 bool RetainExpansion = false;
2365 Optional<unsigned> NumExpansions;
2366 if (SemaRef.CheckParameterPacksForExpansion(D->getLocation(),
2367 TempParams->getSourceRange(),
2370 Expand, RetainExpansion,
2375 for (unsigned I = 0; I != *NumExpansions; ++I) {
2376 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2377 LocalInstantiationScope Scope(SemaRef);
2378 TemplateParameterList *Expansion = SubstTemplateParams(TempParams);
2381 ExpandedParams.push_back(Expansion);
2384 // Note that we have an expanded parameter pack. The "type" of this
2385 // expanded parameter pack is the original expansion type, but callers
2386 // will end up using the expanded parameter pack types for type-checking.
2387 IsExpandedParameterPack = true;
2388 InstParams = TempParams;
2390 // We cannot fully expand the pack expansion now, so just substitute
2391 // into the pattern.
2392 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2394 LocalInstantiationScope Scope(SemaRef);
2395 InstParams = SubstTemplateParams(TempParams);
2400 // Perform the actual substitution of template parameters within a new,
2401 // local instantiation scope.
2402 LocalInstantiationScope Scope(SemaRef);
2403 InstParams = SubstTemplateParams(TempParams);
2408 // Build the template template parameter.
2409 TemplateTemplateParmDecl *Param;
2410 if (IsExpandedParameterPack)
2411 Param = TemplateTemplateParmDecl::Create(
2412 SemaRef.Context, Owner, D->getLocation(),
2413 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2414 D->getPosition(), D->getIdentifier(), InstParams, ExpandedParams);
2416 Param = TemplateTemplateParmDecl::Create(
2417 SemaRef.Context, Owner, D->getLocation(),
2418 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2419 D->getPosition(), D->isParameterPack(), D->getIdentifier(), InstParams);
2420 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2421 NestedNameSpecifierLoc QualifierLoc =
2422 D->getDefaultArgument().getTemplateQualifierLoc();
2424 SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgs);
2425 TemplateName TName = SemaRef.SubstTemplateName(
2426 QualifierLoc, D->getDefaultArgument().getArgument().getAsTemplate(),
2427 D->getDefaultArgument().getTemplateNameLoc(), TemplateArgs);
2428 if (!TName.isNull())
2429 Param->setDefaultArgument(
2431 TemplateArgumentLoc(TemplateArgument(TName),
2432 D->getDefaultArgument().getTemplateQualifierLoc(),
2433 D->getDefaultArgument().getTemplateNameLoc()));
2435 Param->setAccess(AS_public);
2437 // Introduce this template parameter's instantiation into the instantiation
2439 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
2444 Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
2445 // Using directives are never dependent (and never contain any types or
2446 // expressions), so they require no explicit instantiation work.
2448 UsingDirectiveDecl *Inst
2449 = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
2450 D->getNamespaceKeyLocation(),
2451 D->getQualifierLoc(),
2452 D->getIdentLocation(),
2453 D->getNominatedNamespace(),
2454 D->getCommonAncestor());
2456 // Add the using directive to its declaration context
2457 // only if this is not a function or method.
2458 if (!Owner->isFunctionOrMethod())
2459 Owner->addDecl(Inst);
2464 Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
2466 // The nested name specifier may be dependent, for example
2467 // template <typename T> struct t {
2468 // struct s1 { T f1(); };
2469 // struct s2 : s1 { using s1::f1; };
2471 // template struct t<int>;
2472 // Here, in using s1::f1, s1 refers to t<T>::s1;
2473 // we need to substitute for t<int>::s1.
2474 NestedNameSpecifierLoc QualifierLoc
2475 = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
2480 // For an inheriting constructor declaration, the name of the using
2481 // declaration is the name of a constructor in this class, not in the
2483 DeclarationNameInfo NameInfo = D->getNameInfo();
2484 if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName)
2485 if (auto *RD = dyn_cast<CXXRecordDecl>(SemaRef.CurContext))
2486 NameInfo.setName(SemaRef.Context.DeclarationNames.getCXXConstructorName(
2487 SemaRef.Context.getCanonicalType(SemaRef.Context.getRecordType(RD))));
2489 // We only need to do redeclaration lookups if we're in a class
2490 // scope (in fact, it's not really even possible in non-class
2492 bool CheckRedeclaration = Owner->isRecord();
2494 LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
2495 Sema::ForRedeclaration);
2497 UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
2504 SS.Adopt(QualifierLoc);
2505 if (CheckRedeclaration) {
2506 Prev.setHideTags(false);
2507 SemaRef.LookupQualifiedName(Prev, Owner);
2509 // Check for invalid redeclarations.
2510 if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLoc(),
2511 D->hasTypename(), SS,
2512 D->getLocation(), Prev))
2513 NewUD->setInvalidDecl();
2517 if (!NewUD->isInvalidDecl() &&
2518 SemaRef.CheckUsingDeclQualifier(D->getUsingLoc(), D->hasTypename(),
2519 SS, NameInfo, D->getLocation()))
2520 NewUD->setInvalidDecl();
2522 SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
2523 NewUD->setAccess(D->getAccess());
2524 Owner->addDecl(NewUD);
2526 // Don't process the shadow decls for an invalid decl.
2527 if (NewUD->isInvalidDecl())
2530 if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName)
2531 SemaRef.CheckInheritingConstructorUsingDecl(NewUD);
2533 bool isFunctionScope = Owner->isFunctionOrMethod();
2535 // Process the shadow decls.
2536 for (auto *Shadow : D->shadows()) {
2537 // FIXME: UsingShadowDecl doesn't preserve its immediate target, so
2538 // reconstruct it in the case where it matters.
2539 NamedDecl *OldTarget = Shadow->getTargetDecl();
2540 if (auto *CUSD = dyn_cast<ConstructorUsingShadowDecl>(Shadow))
2541 if (auto *BaseShadow = CUSD->getNominatedBaseClassShadowDecl())
2542 OldTarget = BaseShadow;
2544 NamedDecl *InstTarget =
2545 cast_or_null<NamedDecl>(SemaRef.FindInstantiatedDecl(
2546 Shadow->getLocation(), OldTarget, TemplateArgs));
2550 UsingShadowDecl *PrevDecl = nullptr;
2551 if (CheckRedeclaration) {
2552 if (SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev, PrevDecl))
2554 } else if (UsingShadowDecl *OldPrev =
2555 getPreviousDeclForInstantiation(Shadow)) {
2556 PrevDecl = cast_or_null<UsingShadowDecl>(SemaRef.FindInstantiatedDecl(
2557 Shadow->getLocation(), OldPrev, TemplateArgs));
2560 UsingShadowDecl *InstShadow =
2561 SemaRef.BuildUsingShadowDecl(/*Scope*/nullptr, NewUD, InstTarget,
2563 SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
2565 if (isFunctionScope)
2566 SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
2572 Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
2573 // Ignore these; we handle them in bulk when processing the UsingDecl.
2577 Decl *TemplateDeclInstantiator::VisitConstructorUsingShadowDecl(
2578 ConstructorUsingShadowDecl *D) {
2579 // Ignore these; we handle them in bulk when processing the UsingDecl.
2583 template <typename T>
2584 Decl *TemplateDeclInstantiator::instantiateUnresolvedUsingDecl(
2585 T *D, bool InstantiatingPackElement) {
2586 // If this is a pack expansion, expand it now.
2587 if (D->isPackExpansion() && !InstantiatingPackElement) {
2588 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2589 SemaRef.collectUnexpandedParameterPacks(D->getQualifierLoc(), Unexpanded);
2590 SemaRef.collectUnexpandedParameterPacks(D->getNameInfo(), Unexpanded);
2592 // Determine whether the set of unexpanded parameter packs can and should
2595 bool RetainExpansion = false;
2596 Optional<unsigned> NumExpansions;
2597 if (SemaRef.CheckParameterPacksForExpansion(
2598 D->getEllipsisLoc(), D->getSourceRange(), Unexpanded, TemplateArgs,
2599 Expand, RetainExpansion, NumExpansions))
2602 // This declaration cannot appear within a function template signature,
2603 // so we can't have a partial argument list for a parameter pack.
2604 assert(!RetainExpansion &&
2605 "should never need to retain an expansion for UsingPackDecl");
2608 // We cannot fully expand the pack expansion now, so substitute into the
2609 // pattern and create a new pack expansion.
2610 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2611 return instantiateUnresolvedUsingDecl(D, true);
2614 // Within a function, we don't have any normal way to check for conflicts
2615 // between shadow declarations from different using declarations in the
2616 // same pack expansion, but this is always ill-formed because all expansions
2617 // must produce (conflicting) enumerators.
2619 // Sadly we can't just reject this in the template definition because it
2620 // could be valid if the pack is empty or has exactly one expansion.
2621 if (D->getDeclContext()->isFunctionOrMethod() && *NumExpansions > 1) {
2622 SemaRef.Diag(D->getEllipsisLoc(),
2623 diag::err_using_decl_redeclaration_expansion);
2627 // Instantiate the slices of this pack and build a UsingPackDecl.
2628 SmallVector<NamedDecl*, 8> Expansions;
2629 for (unsigned I = 0; I != *NumExpansions; ++I) {
2630 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2631 Decl *Slice = instantiateUnresolvedUsingDecl(D, true);
2634 // Note that we can still get unresolved using declarations here, if we
2635 // had arguments for all packs but the pattern also contained other
2636 // template arguments (this only happens during partial substitution, eg
2637 // into the body of a generic lambda in a function template).
2638 Expansions.push_back(cast<NamedDecl>(Slice));
2641 auto *NewD = SemaRef.BuildUsingPackDecl(D, Expansions);
2642 if (isDeclWithinFunction(D))
2643 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewD);
2647 UnresolvedUsingTypenameDecl *TD = dyn_cast<UnresolvedUsingTypenameDecl>(D);
2648 SourceLocation TypenameLoc = TD ? TD->getTypenameLoc() : SourceLocation();
2650 NestedNameSpecifierLoc QualifierLoc
2651 = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
2657 SS.Adopt(QualifierLoc);
2659 DeclarationNameInfo NameInfo
2660 = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
2662 // Produce a pack expansion only if we're not instantiating a particular
2663 // slice of a pack expansion.
2664 bool InstantiatingSlice = D->getEllipsisLoc().isValid() &&
2665 SemaRef.ArgumentPackSubstitutionIndex != -1;
2666 SourceLocation EllipsisLoc =
2667 InstantiatingSlice ? SourceLocation() : D->getEllipsisLoc();
2669 NamedDecl *UD = SemaRef.BuildUsingDeclaration(
2670 /*Scope*/ nullptr, D->getAccess(), D->getUsingLoc(),
2671 /*HasTypename*/ TD, TypenameLoc, SS, NameInfo, EllipsisLoc, nullptr,
2672 /*IsInstantiation*/ true);
2674 SemaRef.Context.setInstantiatedFromUsingDecl(UD, D);
2679 Decl *TemplateDeclInstantiator::VisitUnresolvedUsingTypenameDecl(
2680 UnresolvedUsingTypenameDecl *D) {
2681 return instantiateUnresolvedUsingDecl(D);
2684 Decl *TemplateDeclInstantiator::VisitUnresolvedUsingValueDecl(
2685 UnresolvedUsingValueDecl *D) {
2686 return instantiateUnresolvedUsingDecl(D);
2689 Decl *TemplateDeclInstantiator::VisitUsingPackDecl(UsingPackDecl *D) {
2690 SmallVector<NamedDecl*, 8> Expansions;
2691 for (auto *UD : D->expansions()) {
2693 SemaRef.FindInstantiatedDecl(D->getLocation(), UD, TemplateArgs))
2694 Expansions.push_back(cast<NamedDecl>(NewUD));
2699 auto *NewD = SemaRef.BuildUsingPackDecl(D, Expansions);
2700 if (isDeclWithinFunction(D))
2701 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewD);
2705 Decl *TemplateDeclInstantiator::VisitClassScopeFunctionSpecializationDecl(
2706 ClassScopeFunctionSpecializationDecl *Decl) {
2707 CXXMethodDecl *OldFD = Decl->getSpecialization();
2708 CXXMethodDecl *NewFD =
2709 cast_or_null<CXXMethodDecl>(VisitCXXMethodDecl(OldFD, nullptr, true));
2713 LookupResult Previous(SemaRef, NewFD->getNameInfo(), Sema::LookupOrdinaryName,
2714 Sema::ForRedeclaration);
2716 TemplateArgumentListInfo TemplateArgs;
2717 TemplateArgumentListInfo *TemplateArgsPtr = nullptr;
2718 if (Decl->hasExplicitTemplateArgs()) {
2719 TemplateArgs = Decl->templateArgs();
2720 TemplateArgsPtr = &TemplateArgs;
2723 SemaRef.LookupQualifiedName(Previous, SemaRef.CurContext);
2724 if (SemaRef.CheckFunctionTemplateSpecialization(NewFD, TemplateArgsPtr,
2726 NewFD->setInvalidDecl();
2730 // Associate the specialization with the pattern.
2731 FunctionDecl *Specialization = cast<FunctionDecl>(Previous.getFoundDecl());
2732 assert(Specialization && "Class scope Specialization is null");
2733 SemaRef.Context.setClassScopeSpecializationPattern(Specialization, OldFD);
2738 Decl *TemplateDeclInstantiator::VisitOMPThreadPrivateDecl(
2739 OMPThreadPrivateDecl *D) {
2740 SmallVector<Expr *, 5> Vars;
2741 for (auto *I : D->varlists()) {
2742 Expr *Var = SemaRef.SubstExpr(I, TemplateArgs).get();
2743 assert(isa<DeclRefExpr>(Var) && "threadprivate arg is not a DeclRefExpr");
2744 Vars.push_back(Var);
2747 OMPThreadPrivateDecl *TD =
2748 SemaRef.CheckOMPThreadPrivateDecl(D->getLocation(), Vars);
2750 TD->setAccess(AS_public);
2756 Decl *TemplateDeclInstantiator::VisitOMPDeclareReductionDecl(
2757 OMPDeclareReductionDecl *D) {
2758 // Instantiate type and check if it is allowed.
2759 QualType SubstReductionType = SemaRef.ActOnOpenMPDeclareReductionType(
2761 ParsedType::make(SemaRef.SubstType(D->getType(), TemplateArgs,
2762 D->getLocation(), DeclarationName())));
2763 if (SubstReductionType.isNull())
2765 bool IsCorrect = !SubstReductionType.isNull();
2766 // Create instantiated copy.
2767 std::pair<QualType, SourceLocation> ReductionTypes[] = {
2768 std::make_pair(SubstReductionType, D->getLocation())};
2769 auto *PrevDeclInScope = D->getPrevDeclInScope();
2770 if (PrevDeclInScope && !PrevDeclInScope->isInvalidDecl()) {
2771 PrevDeclInScope = cast<OMPDeclareReductionDecl>(
2772 SemaRef.CurrentInstantiationScope->findInstantiationOf(PrevDeclInScope)
2775 auto DRD = SemaRef.ActOnOpenMPDeclareReductionDirectiveStart(
2776 /*S=*/nullptr, Owner, D->getDeclName(), ReductionTypes, D->getAccess(),
2778 auto *NewDRD = cast<OMPDeclareReductionDecl>(DRD.get().getSingleDecl());
2779 if (isDeclWithinFunction(NewDRD))
2780 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewDRD);
2781 Expr *SubstCombiner = nullptr;
2782 Expr *SubstInitializer = nullptr;
2783 // Combiners instantiation sequence.
2784 if (D->getCombiner()) {
2785 SemaRef.ActOnOpenMPDeclareReductionCombinerStart(
2786 /*S=*/nullptr, NewDRD);
2787 const char *Names[] = {"omp_in", "omp_out"};
2788 for (auto &Name : Names) {
2789 DeclarationName DN(&SemaRef.Context.Idents.get(Name));
2790 auto OldLookup = D->lookup(DN);
2791 auto Lookup = NewDRD->lookup(DN);
2792 if (!OldLookup.empty() && !Lookup.empty()) {
2793 assert(Lookup.size() == 1 && OldLookup.size() == 1);
2794 SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldLookup.front(),
2798 SubstCombiner = SemaRef.SubstExpr(D->getCombiner(), TemplateArgs).get();
2799 SemaRef.ActOnOpenMPDeclareReductionCombinerEnd(NewDRD, SubstCombiner);
2800 // Initializers instantiation sequence.
2801 if (D->getInitializer()) {
2802 SemaRef.ActOnOpenMPDeclareReductionInitializerStart(
2803 /*S=*/nullptr, NewDRD);
2804 const char *Names[] = {"omp_orig", "omp_priv"};
2805 for (auto &Name : Names) {
2806 DeclarationName DN(&SemaRef.Context.Idents.get(Name));
2807 auto OldLookup = D->lookup(DN);
2808 auto Lookup = NewDRD->lookup(DN);
2809 if (!OldLookup.empty() && !Lookup.empty()) {
2810 assert(Lookup.size() == 1 && OldLookup.size() == 1);
2811 SemaRef.CurrentInstantiationScope->InstantiatedLocal(
2812 OldLookup.front(), Lookup.front());
2816 SemaRef.SubstExpr(D->getInitializer(), TemplateArgs).get();
2817 SemaRef.ActOnOpenMPDeclareReductionInitializerEnd(NewDRD,
2820 IsCorrect = IsCorrect && SubstCombiner &&
2821 (!D->getInitializer() || SubstInitializer);
2825 (void)SemaRef.ActOnOpenMPDeclareReductionDirectiveEnd(/*S=*/nullptr, DRD,
2831 Decl *TemplateDeclInstantiator::VisitOMPCapturedExprDecl(
2832 OMPCapturedExprDecl * /*D*/) {
2833 llvm_unreachable("Should not be met in templates");
2836 Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D) {
2837 return VisitFunctionDecl(D, nullptr);
2841 TemplateDeclInstantiator::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
2842 return VisitFunctionDecl(D, nullptr);
2845 Decl *TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D) {
2846 return VisitCXXMethodDecl(D, nullptr);
2849 Decl *TemplateDeclInstantiator::VisitRecordDecl(RecordDecl *D) {
2850 llvm_unreachable("There are only CXXRecordDecls in C++");
2854 TemplateDeclInstantiator::VisitClassTemplateSpecializationDecl(
2855 ClassTemplateSpecializationDecl *D) {
2856 // As a MS extension, we permit class-scope explicit specialization
2857 // of member class templates.
2858 ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
2859 assert(ClassTemplate->getDeclContext()->isRecord() &&
2860 D->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
2861 "can only instantiate an explicit specialization "
2862 "for a member class template");
2864 // Lookup the already-instantiated declaration in the instantiation
2865 // of the class template. FIXME: Diagnose or assert if this fails?
2866 DeclContext::lookup_result Found
2867 = Owner->lookup(ClassTemplate->getDeclName());
2870 ClassTemplateDecl *InstClassTemplate
2871 = dyn_cast<ClassTemplateDecl>(Found.front());
2872 if (!InstClassTemplate)
2875 // Substitute into the template arguments of the class template explicit
2877 TemplateSpecializationTypeLoc Loc = D->getTypeAsWritten()->getTypeLoc().
2878 castAs<TemplateSpecializationTypeLoc>();
2879 TemplateArgumentListInfo InstTemplateArgs(Loc.getLAngleLoc(),
2880 Loc.getRAngleLoc());
2881 SmallVector<TemplateArgumentLoc, 4> ArgLocs;
2882 for (unsigned I = 0; I != Loc.getNumArgs(); ++I)
2883 ArgLocs.push_back(Loc.getArgLoc(I));
2884 if (SemaRef.Subst(ArgLocs.data(), ArgLocs.size(),
2885 InstTemplateArgs, TemplateArgs))
2888 // Check that the template argument list is well-formed for this
2890 SmallVector<TemplateArgument, 4> Converted;
2891 if (SemaRef.CheckTemplateArgumentList(InstClassTemplate,
2898 // Figure out where to insert this class template explicit specialization
2899 // in the member template's set of class template explicit specializations.
2900 void *InsertPos = nullptr;
2901 ClassTemplateSpecializationDecl *PrevDecl =
2902 InstClassTemplate->findSpecialization(Converted, InsertPos);
2904 // Check whether we've already seen a conflicting instantiation of this
2905 // declaration (for instance, if there was a prior implicit instantiation).
2908 SemaRef.CheckSpecializationInstantiationRedecl(D->getLocation(),
2909 D->getSpecializationKind(),
2911 PrevDecl->getSpecializationKind(),
2912 PrevDecl->getPointOfInstantiation(),
2916 // If PrevDecl was a definition and D is also a definition, diagnose.
2917 // This happens in cases like:
2919 // template<typename T, typename U>
2921 // template<typename X> struct Inner;
2922 // template<> struct Inner<T> {};
2923 // template<> struct Inner<U> {};
2926 // Outer<int, int> outer; // error: the explicit specializations of Inner
2927 // // have the same signature.
2928 if (PrevDecl && PrevDecl->getDefinition() &&
2929 D->isThisDeclarationADefinition()) {
2930 SemaRef.Diag(D->getLocation(), diag::err_redefinition) << PrevDecl;
2931 SemaRef.Diag(PrevDecl->getDefinition()->getLocation(),
2932 diag::note_previous_definition);
2936 // Create the class template partial specialization declaration.
2937 ClassTemplateSpecializationDecl *InstD
2938 = ClassTemplateSpecializationDecl::Create(SemaRef.Context,
2947 // Add this partial specialization to the set of class template partial
2950 InstClassTemplate->AddSpecialization(InstD, InsertPos);
2952 // Substitute the nested name specifier, if any.
2953 if (SubstQualifier(D, InstD))
2956 // Build the canonical type that describes the converted template
2957 // arguments of the class template explicit specialization.
2958 QualType CanonType = SemaRef.Context.getTemplateSpecializationType(
2959 TemplateName(InstClassTemplate), Converted,
2960 SemaRef.Context.getRecordType(InstD));
2962 // Build the fully-sugared type for this class template
2963 // specialization as the user wrote in the specialization
2964 // itself. This means that we'll pretty-print the type retrieved
2965 // from the specialization's declaration the way that the user
2966 // actually wrote the specialization, rather than formatting the
2967 // name based on the "canonical" representation used to store the
2968 // template arguments in the specialization.
2969 TypeSourceInfo *WrittenTy = SemaRef.Context.getTemplateSpecializationTypeInfo(
2970 TemplateName(InstClassTemplate), D->getLocation(), InstTemplateArgs,
2973 InstD->setAccess(D->getAccess());
2974 InstD->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
2975 InstD->setSpecializationKind(D->getSpecializationKind());
2976 InstD->setTypeAsWritten(WrittenTy);
2977 InstD->setExternLoc(D->getExternLoc());
2978 InstD->setTemplateKeywordLoc(D->getTemplateKeywordLoc());
2980 Owner->addDecl(InstD);
2982 // Instantiate the members of the class-scope explicit specialization eagerly.
2983 // We don't have support for lazy instantiation of an explicit specialization
2984 // yet, and MSVC eagerly instantiates in this case.
2985 if (D->isThisDeclarationADefinition() &&
2986 SemaRef.InstantiateClass(D->getLocation(), InstD, D, TemplateArgs,
2987 TSK_ImplicitInstantiation,
2994 Decl *TemplateDeclInstantiator::VisitVarTemplateSpecializationDecl(
2995 VarTemplateSpecializationDecl *D) {
2997 TemplateArgumentListInfo VarTemplateArgsInfo;
2998 VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
2999 assert(VarTemplate &&
3000 "A template specialization without specialized template?");
3002 // Substitute the current template arguments.
3003 const TemplateArgumentListInfo &TemplateArgsInfo = D->getTemplateArgsInfo();
3004 VarTemplateArgsInfo.setLAngleLoc(TemplateArgsInfo.getLAngleLoc());
3005 VarTemplateArgsInfo.setRAngleLoc(TemplateArgsInfo.getRAngleLoc());
3007 if (SemaRef.Subst(TemplateArgsInfo.getArgumentArray(),
3008 TemplateArgsInfo.size(), VarTemplateArgsInfo, TemplateArgs))
3011 // Check that the template argument list is well-formed for this template.
3012 SmallVector<TemplateArgument, 4> Converted;
3013 if (SemaRef.CheckTemplateArgumentList(
3014 VarTemplate, VarTemplate->getLocStart(),
3015 const_cast<TemplateArgumentListInfo &>(VarTemplateArgsInfo), false,
3019 // Find the variable template specialization declaration that
3020 // corresponds to these arguments.
3021 void *InsertPos = nullptr;
3022 if (VarTemplateSpecializationDecl *VarSpec = VarTemplate->findSpecialization(
3023 Converted, InsertPos))
3024 // If we already have a variable template specialization, return it.
3027 return VisitVarTemplateSpecializationDecl(VarTemplate, D, InsertPos,
3028 VarTemplateArgsInfo, Converted);
3031 Decl *TemplateDeclInstantiator::VisitVarTemplateSpecializationDecl(
3032 VarTemplateDecl *VarTemplate, VarDecl *D, void *InsertPos,
3033 const TemplateArgumentListInfo &TemplateArgsInfo,
3034 ArrayRef<TemplateArgument> Converted) {
3036 // Do substitution on the type of the declaration
3037 TypeSourceInfo *DI =
3038 SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
3039 D->getTypeSpecStartLoc(), D->getDeclName());
3043 if (DI->getType()->isFunctionType()) {
3044 SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
3045 << D->isStaticDataMember() << DI->getType();
3049 // Build the instantiated declaration
3050 VarTemplateSpecializationDecl *Var = VarTemplateSpecializationDecl::Create(
3051 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
3052 VarTemplate, DI->getType(), DI, D->getStorageClass(), Converted);
3053 Var->setTemplateArgsInfo(TemplateArgsInfo);
3055 VarTemplate->AddSpecialization(Var, InsertPos);
3057 // Substitute the nested name specifier, if any.
3058 if (SubstQualifier(D, Var))
3061 SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs,
3062 Owner, StartingScope);
3067 Decl *TemplateDeclInstantiator::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
3068 llvm_unreachable("@defs is not supported in Objective-C++");
3071 Decl *TemplateDeclInstantiator::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
3072 // FIXME: We need to be able to instantiate FriendTemplateDecls.
3073 unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
3074 DiagnosticsEngine::Error,
3075 "cannot instantiate %0 yet");
3076 SemaRef.Diag(D->getLocation(), DiagID)
3077 << D->getDeclKindName();
3082 Decl *TemplateDeclInstantiator::VisitDecl(Decl *D) {
3083 llvm_unreachable("Unexpected decl");
3086 Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
3087 const MultiLevelTemplateArgumentList &TemplateArgs) {
3088 TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
3089 if (D->isInvalidDecl())
3092 return Instantiator.Visit(D);
3095 /// \brief Instantiates a nested template parameter list in the current
3096 /// instantiation context.
3098 /// \param L The parameter list to instantiate
3100 /// \returns NULL if there was an error
3101 TemplateParameterList *
3102 TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
3103 // Get errors for all the parameters before bailing out.
3104 bool Invalid = false;
3106 unsigned N = L->size();
3107 typedef SmallVector<NamedDecl *, 8> ParamVector;
3110 for (auto &P : *L) {
3111 NamedDecl *D = cast_or_null<NamedDecl>(Visit(P));
3112 Params.push_back(D);
3113 Invalid = Invalid || !D || D->isInvalidDecl();
3116 // Clean up if we had an error.
3120 // Note: we substitute into associated constraints later
3121 Expr *const UninstantiatedRequiresClause = L->getRequiresClause();
3123 TemplateParameterList *InstL
3124 = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
3125 L->getLAngleLoc(), Params,
3127 UninstantiatedRequiresClause);
3131 /// \brief Instantiate the declaration of a class template partial
3134 /// \param ClassTemplate the (instantiated) class template that is partially
3135 // specialized by the instantiation of \p PartialSpec.
3137 /// \param PartialSpec the (uninstantiated) class template partial
3138 /// specialization that we are instantiating.
3140 /// \returns The instantiated partial specialization, if successful; otherwise,
3141 /// NULL to indicate an error.
3142 ClassTemplatePartialSpecializationDecl *
3143 TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
3144 ClassTemplateDecl *ClassTemplate,
3145 ClassTemplatePartialSpecializationDecl *PartialSpec) {
3146 // Create a local instantiation scope for this class template partial
3147 // specialization, which will contain the instantiations of the template
3149 LocalInstantiationScope Scope(SemaRef);
3151 // Substitute into the template parameters of the class template partial
3153 TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
3154 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
3158 // Substitute into the template arguments of the class template partial
3160 const ASTTemplateArgumentListInfo *TemplArgInfo
3161 = PartialSpec->getTemplateArgsAsWritten();
3162 TemplateArgumentListInfo InstTemplateArgs(TemplArgInfo->LAngleLoc,
3163 TemplArgInfo->RAngleLoc);
3164 if (SemaRef.Subst(TemplArgInfo->getTemplateArgs(),
3165 TemplArgInfo->NumTemplateArgs,
3166 InstTemplateArgs, TemplateArgs))
3169 // Check that the template argument list is well-formed for this
3171 SmallVector<TemplateArgument, 4> Converted;
3172 if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
3173 PartialSpec->getLocation(),
3179 // Check these arguments are valid for a template partial specialization.
3180 if (SemaRef.CheckTemplatePartialSpecializationArgs(
3181 PartialSpec->getLocation(), ClassTemplate, InstTemplateArgs.size(),
3185 // Figure out where to insert this class template partial specialization
3186 // in the member template's set of class template partial specializations.
3187 void *InsertPos = nullptr;
3188 ClassTemplateSpecializationDecl *PrevDecl
3189 = ClassTemplate->findPartialSpecialization(Converted, InsertPos);
3191 // Build the canonical type that describes the converted template
3192 // arguments of the class template partial specialization.
3194 = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
3197 // Build the fully-sugared type for this class template
3198 // specialization as the user wrote in the specialization
3199 // itself. This means that we'll pretty-print the type retrieved
3200 // from the specialization's declaration the way that the user
3201 // actually wrote the specialization, rather than formatting the
3202 // name based on the "canonical" representation used to store the
3203 // template arguments in the specialization.
3204 TypeSourceInfo *WrittenTy
3205 = SemaRef.Context.getTemplateSpecializationTypeInfo(
3206 TemplateName(ClassTemplate),
3207 PartialSpec->getLocation(),
3212 // We've already seen a partial specialization with the same template
3213 // parameters and template arguments. This can happen, for example, when
3214 // substituting the outer template arguments ends up causing two
3215 // class template partial specializations of a member class template
3216 // to have identical forms, e.g.,
3218 // template<typename T, typename U>
3220 // template<typename X, typename Y> struct Inner;
3221 // template<typename Y> struct Inner<T, Y>;
3222 // template<typename Y> struct Inner<U, Y>;
3225 // Outer<int, int> outer; // error: the partial specializations of Inner
3226 // // have the same signature.
3227 SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
3228 << WrittenTy->getType();
3229 SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
3230 << SemaRef.Context.getTypeDeclType(PrevDecl);
3235 // Create the class template partial specialization declaration.
3236 ClassTemplatePartialSpecializationDecl *InstPartialSpec
3237 = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
3238 PartialSpec->getTagKind(),
3240 PartialSpec->getLocStart(),
3241 PartialSpec->getLocation(),
3248 // Substitute the nested name specifier, if any.
3249 if (SubstQualifier(PartialSpec, InstPartialSpec))
3252 InstPartialSpec->setInstantiatedFromMember(PartialSpec);
3253 InstPartialSpec->setTypeAsWritten(WrittenTy);
3255 // Check the completed partial specialization.
3256 SemaRef.CheckTemplatePartialSpecialization(InstPartialSpec);
3258 // Add this partial specialization to the set of class template partial
3260 ClassTemplate->AddPartialSpecialization(InstPartialSpec,
3261 /*InsertPos=*/nullptr);
3262 return InstPartialSpec;
3265 /// \brief Instantiate the declaration of a variable template partial
3268 /// \param VarTemplate the (instantiated) variable template that is partially
3269 /// specialized by the instantiation of \p PartialSpec.
3271 /// \param PartialSpec the (uninstantiated) variable template partial
3272 /// specialization that we are instantiating.
3274 /// \returns The instantiated partial specialization, if successful; otherwise,
3275 /// NULL to indicate an error.
3276 VarTemplatePartialSpecializationDecl *
3277 TemplateDeclInstantiator::InstantiateVarTemplatePartialSpecialization(
3278 VarTemplateDecl *VarTemplate,
3279 VarTemplatePartialSpecializationDecl *PartialSpec) {
3280 // Create a local instantiation scope for this variable template partial
3281 // specialization, which will contain the instantiations of the template
3283 LocalInstantiationScope Scope(SemaRef);
3285 // Substitute into the template parameters of the variable template partial
3287 TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
3288 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
3292 // Substitute into the template arguments of the variable template partial
3294 const ASTTemplateArgumentListInfo *TemplArgInfo
3295 = PartialSpec->getTemplateArgsAsWritten();
3296 TemplateArgumentListInfo InstTemplateArgs(TemplArgInfo->LAngleLoc,
3297 TemplArgInfo->RAngleLoc);
3298 if (SemaRef.Subst(TemplArgInfo->getTemplateArgs(),
3299 TemplArgInfo->NumTemplateArgs,
3300 InstTemplateArgs, TemplateArgs))
3303 // Check that the template argument list is well-formed for this
3305 SmallVector<TemplateArgument, 4> Converted;
3306 if (SemaRef.CheckTemplateArgumentList(VarTemplate, PartialSpec->getLocation(),
3307 InstTemplateArgs, false, Converted))
3310 // Check these arguments are valid for a template partial specialization.
3311 if (SemaRef.CheckTemplatePartialSpecializationArgs(
3312 PartialSpec->getLocation(), VarTemplate, InstTemplateArgs.size(),
3316 // Figure out where to insert this variable template partial specialization
3317 // in the member template's set of variable template partial specializations.
3318 void *InsertPos = nullptr;
3319 VarTemplateSpecializationDecl *PrevDecl =
3320 VarTemplate->findPartialSpecialization(Converted, InsertPos);
3322 // Build the canonical type that describes the converted template
3323 // arguments of the variable template partial specialization.
3324 QualType CanonType = SemaRef.Context.getTemplateSpecializationType(
3325 TemplateName(VarTemplate), Converted);
3327 // Build the fully-sugared type for this variable template
3328 // specialization as the user wrote in the specialization
3329 // itself. This means that we'll pretty-print the type retrieved
3330 // from the specialization's declaration the way that the user
3331 // actually wrote the specialization, rather than formatting the
3332 // name based on the "canonical" representation used to store the
3333 // template arguments in the specialization.
3334 TypeSourceInfo *WrittenTy = SemaRef.Context.getTemplateSpecializationTypeInfo(
3335 TemplateName(VarTemplate), PartialSpec->getLocation(), InstTemplateArgs,
3339 // We've already seen a partial specialization with the same template
3340 // parameters and template arguments. This can happen, for example, when
3341 // substituting the outer template arguments ends up causing two
3342 // variable template partial specializations of a member variable template
3343 // to have identical forms, e.g.,
3345 // template<typename T, typename U>
3347 // template<typename X, typename Y> pair<X,Y> p;
3348 // template<typename Y> pair<T, Y> p;
3349 // template<typename Y> pair<U, Y> p;
3352 // Outer<int, int> outer; // error: the partial specializations of Inner
3353 // // have the same signature.
3354 SemaRef.Diag(PartialSpec->getLocation(),
3355 diag::err_var_partial_spec_redeclared)
3356 << WrittenTy->getType();
3357 SemaRef.Diag(PrevDecl->getLocation(),
3358 diag::note_var_prev_partial_spec_here);
3362 // Do substitution on the type of the declaration
3363 TypeSourceInfo *DI = SemaRef.SubstType(
3364 PartialSpec->getTypeSourceInfo(), TemplateArgs,
3365 PartialSpec->getTypeSpecStartLoc(), PartialSpec->getDeclName());
3369 if (DI->getType()->isFunctionType()) {
3370 SemaRef.Diag(PartialSpec->getLocation(),
3371 diag::err_variable_instantiates_to_function)
3372 << PartialSpec->isStaticDataMember() << DI->getType();
3376 // Create the variable template partial specialization declaration.
3377 VarTemplatePartialSpecializationDecl *InstPartialSpec =
3378 VarTemplatePartialSpecializationDecl::Create(
3379 SemaRef.Context, Owner, PartialSpec->getInnerLocStart(),
3380 PartialSpec->getLocation(), InstParams, VarTemplate, DI->getType(),
3381 DI, PartialSpec->getStorageClass(), Converted, InstTemplateArgs);
3383 // Substitute the nested name specifier, if any.
3384 if (SubstQualifier(PartialSpec, InstPartialSpec))
3387 InstPartialSpec->setInstantiatedFromMember(PartialSpec);
3388 InstPartialSpec->setTypeAsWritten(WrittenTy);
3390 // Check the completed partial specialization.
3391 SemaRef.CheckTemplatePartialSpecialization(InstPartialSpec);
3393 // Add this partial specialization to the set of variable template partial
3394 // specializations. The instantiation of the initializer is not necessary.
3395 VarTemplate->AddPartialSpecialization(InstPartialSpec, /*InsertPos=*/nullptr);
3397 SemaRef.BuildVariableInstantiation(InstPartialSpec, PartialSpec, TemplateArgs,
3398 LateAttrs, Owner, StartingScope);
3400 return InstPartialSpec;
3404 TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
3405 SmallVectorImpl<ParmVarDecl *> &Params) {
3406 TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
3407 assert(OldTInfo && "substituting function without type source info");
3408 assert(Params.empty() && "parameter vector is non-empty at start");
3410 CXXRecordDecl *ThisContext = nullptr;
3411 unsigned ThisTypeQuals = 0;
3412 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
3413 ThisContext = cast<CXXRecordDecl>(Owner);
3414 ThisTypeQuals = Method->getTypeQualifiers();
3417 TypeSourceInfo *NewTInfo
3418 = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
3419 D->getTypeSpecStartLoc(),
3421 ThisContext, ThisTypeQuals);
3425 TypeLoc OldTL = OldTInfo->getTypeLoc().IgnoreParens();
3426 if (FunctionProtoTypeLoc OldProtoLoc = OldTL.getAs<FunctionProtoTypeLoc>()) {
3427 if (NewTInfo != OldTInfo) {
3428 // Get parameters from the new type info.
3429 TypeLoc NewTL = NewTInfo->getTypeLoc().IgnoreParens();
3430 FunctionProtoTypeLoc NewProtoLoc = NewTL.castAs<FunctionProtoTypeLoc>();
3431 unsigned NewIdx = 0;
3432 for (unsigned OldIdx = 0, NumOldParams = OldProtoLoc.getNumParams();
3433 OldIdx != NumOldParams; ++OldIdx) {
3434 ParmVarDecl *OldParam = OldProtoLoc.getParam(OldIdx);
3435 LocalInstantiationScope *Scope = SemaRef.CurrentInstantiationScope;
3437 Optional<unsigned> NumArgumentsInExpansion;
3438 if (OldParam->isParameterPack())
3439 NumArgumentsInExpansion =
3440 SemaRef.getNumArgumentsInExpansion(OldParam->getType(),
3442 if (!NumArgumentsInExpansion) {
3443 // Simple case: normal parameter, or a parameter pack that's
3444 // instantiated to a (still-dependent) parameter pack.
3445 ParmVarDecl *NewParam = NewProtoLoc.getParam(NewIdx++);
3446 Params.push_back(NewParam);
3447 Scope->InstantiatedLocal(OldParam, NewParam);
3449 // Parameter pack expansion: make the instantiation an argument pack.
3450 Scope->MakeInstantiatedLocalArgPack(OldParam);
3451 for (unsigned I = 0; I != *NumArgumentsInExpansion; ++I) {
3452 ParmVarDecl *NewParam = NewProtoLoc.getParam(NewIdx++);
3453 Params.push_back(NewParam);
3454 Scope->InstantiatedLocalPackArg(OldParam, NewParam);
3459 // The function type itself was not dependent and therefore no
3460 // substitution occurred. However, we still need to instantiate
3461 // the function parameters themselves.
3462 const FunctionProtoType *OldProto =
3463 cast<FunctionProtoType>(OldProtoLoc.getType());
3464 for (unsigned i = 0, i_end = OldProtoLoc.getNumParams(); i != i_end;
3466 ParmVarDecl *OldParam = OldProtoLoc.getParam(i);
3468 Params.push_back(SemaRef.BuildParmVarDeclForTypedef(
3469 D, D->getLocation(), OldProto->getParamType(i)));
3474 cast_or_null<ParmVarDecl>(VisitParmVarDecl(OldParam));
3477 Params.push_back(Parm);
3481 // If the type of this function, after ignoring parentheses, is not
3482 // *directly* a function type, then we're instantiating a function that
3483 // was declared via a typedef or with attributes, e.g.,
3485 // typedef int functype(int, int);
3487 // int __cdecl meth(int, int);
3489 // In this case, we'll just go instantiate the ParmVarDecls that we
3490 // synthesized in the method declaration.
3491 SmallVector<QualType, 4> ParamTypes;
3492 Sema::ExtParameterInfoBuilder ExtParamInfos;
3493 if (SemaRef.SubstParmTypes(D->getLocation(), D->parameters(), nullptr,
3494 TemplateArgs, ParamTypes, &Params,
3502 /// Introduce the instantiated function parameters into the local
3503 /// instantiation scope, and set the parameter names to those used
3504 /// in the template.
3505 static bool addInstantiatedParametersToScope(Sema &S, FunctionDecl *Function,
3506 const FunctionDecl *PatternDecl,
3507 LocalInstantiationScope &Scope,
3508 const MultiLevelTemplateArgumentList &TemplateArgs) {
3509 unsigned FParamIdx = 0;
3510 for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
3511 const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
3512 if (!PatternParam->isParameterPack()) {
3513 // Simple case: not a parameter pack.
3514 assert(FParamIdx < Function->getNumParams());
3515 ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
3516 FunctionParam->setDeclName(PatternParam->getDeclName());
3517 // If the parameter's type is not dependent, update it to match the type
3518 // in the pattern. They can differ in top-level cv-qualifiers, and we want
3519 // the pattern's type here. If the type is dependent, they can't differ,
3520 // per core issue 1668. Substitute into the type from the pattern, in case
3521 // it's instantiation-dependent.
3522 // FIXME: Updating the type to work around this is at best fragile.
3523 if (!PatternDecl->getType()->isDependentType()) {
3524 QualType T = S.SubstType(PatternParam->getType(), TemplateArgs,
3525 FunctionParam->getLocation(),
3526 FunctionParam->getDeclName());
3529 FunctionParam->setType(T);
3532 Scope.InstantiatedLocal(PatternParam, FunctionParam);
3537 // Expand the parameter pack.
3538 Scope.MakeInstantiatedLocalArgPack(PatternParam);
3539 Optional<unsigned> NumArgumentsInExpansion
3540 = S.getNumArgumentsInExpansion(PatternParam->getType(), TemplateArgs);
3541 assert(NumArgumentsInExpansion &&
3542 "should only be called when all template arguments are known");
3543 QualType PatternType =
3544 PatternParam->getType()->castAs<PackExpansionType>()->getPattern();
3545 for (unsigned Arg = 0; Arg < *NumArgumentsInExpansion; ++Arg) {
3546 ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
3547 FunctionParam->setDeclName(PatternParam->getDeclName());
3548 if (!PatternDecl->getType()->isDependentType()) {
3549 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, Arg);
3550 QualType T = S.SubstType(PatternType, TemplateArgs,
3551 FunctionParam->getLocation(),
3552 FunctionParam->getDeclName());
3555 FunctionParam->setType(T);
3558 Scope.InstantiatedLocalPackArg(PatternParam, FunctionParam);
3566 void Sema::InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
3567 FunctionDecl *Decl) {
3568 const FunctionProtoType *Proto = Decl->getType()->castAs<FunctionProtoType>();
3569 if (Proto->getExceptionSpecType() != EST_Uninstantiated)
3572 InstantiatingTemplate Inst(*this, PointOfInstantiation, Decl,
3573 InstantiatingTemplate::ExceptionSpecification());
3574 if (Inst.isInvalid()) {
3575 // We hit the instantiation depth limit. Clear the exception specification
3576 // so that our callers don't have to cope with EST_Uninstantiated.
3577 UpdateExceptionSpec(Decl, EST_None);
3580 if (Inst.isAlreadyInstantiating()) {
3581 // This exception specification indirectly depends on itself. Reject.
3582 // FIXME: Corresponding rule in the standard?
3583 Diag(PointOfInstantiation, diag::err_exception_spec_cycle) << Decl;
3584 UpdateExceptionSpec(Decl, EST_None);
3588 // Enter the scope of this instantiation. We don't use
3589 // PushDeclContext because we don't have a scope.
3590 Sema::ContextRAII savedContext(*this, Decl);
3591 LocalInstantiationScope Scope(*this);
3593 MultiLevelTemplateArgumentList TemplateArgs =
3594 getTemplateInstantiationArgs(Decl, nullptr, /*RelativeToPrimary*/true);
3596 FunctionDecl *Template = Proto->getExceptionSpecTemplate();
3597 if (addInstantiatedParametersToScope(*this, Decl, Template, Scope,
3599 UpdateExceptionSpec(Decl, EST_None);
3603 SubstExceptionSpec(Decl, Template->getType()->castAs<FunctionProtoType>(),
3607 /// \brief Initializes the common fields of an instantiation function
3608 /// declaration (New) from the corresponding fields of its template (Tmpl).
3610 /// \returns true if there was an error
3612 TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
3613 FunctionDecl *Tmpl) {
3614 if (Tmpl->isDeleted())
3615 New->setDeletedAsWritten();
3617 New->setImplicit(Tmpl->isImplicit());
3619 // Forward the mangling number from the template to the instantiated decl.
3620 SemaRef.Context.setManglingNumber(New,
3621 SemaRef.Context.getManglingNumber(Tmpl));
3623 // If we are performing substituting explicitly-specified template arguments
3624 // or deduced template arguments into a function template and we reach this
3625 // point, we are now past the point where SFINAE applies and have committed
3626 // to keeping the new function template specialization. We therefore
3627 // convert the active template instantiation for the function template
3628 // into a template instantiation for this specific function template
3629 // specialization, which is not a SFINAE context, so that we diagnose any
3630 // further errors in the declaration itself.
3631 typedef Sema::CodeSynthesisContext ActiveInstType;
3632 ActiveInstType &ActiveInst = SemaRef.CodeSynthesisContexts.back();
3633 if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
3634 ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
3635 if (FunctionTemplateDecl *FunTmpl
3636 = dyn_cast<FunctionTemplateDecl>(ActiveInst.Entity)) {
3637 assert(FunTmpl->getTemplatedDecl() == Tmpl &&
3638 "Deduction from the wrong function template?");
3640 ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
3641 ActiveInst.Entity = New;
3645 const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
3646 assert(Proto && "Function template without prototype?");
3648 if (Proto->hasExceptionSpec() || Proto->getNoReturnAttr()) {
3649 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
3651 // DR1330: In C++11, defer instantiation of a non-trivial
3652 // exception specification.
3653 // DR1484: Local classes and their members are instantiated along with the
3654 // containing function.
3655 if (SemaRef.getLangOpts().CPlusPlus11 &&
3656 EPI.ExceptionSpec.Type != EST_None &&
3657 EPI.ExceptionSpec.Type != EST_DynamicNone &&
3658 EPI.ExceptionSpec.Type != EST_BasicNoexcept &&
3659 !Tmpl->isLexicallyWithinFunctionOrMethod()) {
3660 FunctionDecl *ExceptionSpecTemplate = Tmpl;
3661 if (EPI.ExceptionSpec.Type == EST_Uninstantiated)
3662 ExceptionSpecTemplate = EPI.ExceptionSpec.SourceTemplate;
3663 ExceptionSpecificationType NewEST = EST_Uninstantiated;
3664 if (EPI.ExceptionSpec.Type == EST_Unevaluated)
3665 NewEST = EST_Unevaluated;
3667 // Mark the function has having an uninstantiated exception specification.
3668 const FunctionProtoType *NewProto
3669 = New->getType()->getAs<FunctionProtoType>();
3670 assert(NewProto && "Template instantiation without function prototype?");
3671 EPI = NewProto->getExtProtoInfo();
3672 EPI.ExceptionSpec.Type = NewEST;
3673 EPI.ExceptionSpec.SourceDecl = New;
3674 EPI.ExceptionSpec.SourceTemplate = ExceptionSpecTemplate;
3675 New->setType(SemaRef.Context.getFunctionType(
3676 NewProto->getReturnType(), NewProto->getParamTypes(), EPI));
3678 Sema::ContextRAII SwitchContext(SemaRef, New);
3679 SemaRef.SubstExceptionSpec(New, Proto, TemplateArgs);
3683 // Get the definition. Leaves the variable unchanged if undefined.
3684 const FunctionDecl *Definition = Tmpl;
3685 Tmpl->isDefined(Definition);
3687 SemaRef.InstantiateAttrs(TemplateArgs, Definition, New,
3688 LateAttrs, StartingScope);
3693 /// \brief Initializes common fields of an instantiated method
3694 /// declaration (New) from the corresponding fields of its template
3697 /// \returns true if there was an error
3699 TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
3700 CXXMethodDecl *Tmpl) {
3701 if (InitFunctionInstantiation(New, Tmpl))
3704 New->setAccess(Tmpl->getAccess());
3705 if (Tmpl->isVirtualAsWritten())
3706 New->setVirtualAsWritten(true);
3708 // FIXME: New needs a pointer to Tmpl
3712 /// In the MS ABI, we need to instantiate default arguments of dllexported
3713 /// default constructors along with the constructor definition. This allows IR
3714 /// gen to emit a constructor closure which calls the default constructor with
3715 /// its default arguments.
3716 static void InstantiateDefaultCtorDefaultArgs(Sema &S,
3717 CXXConstructorDecl *Ctor) {
3718 assert(S.Context.getTargetInfo().getCXXABI().isMicrosoft() &&
3719 Ctor->isDefaultConstructor());
3720 unsigned NumParams = Ctor->getNumParams();
3723 DLLExportAttr *Attr = Ctor->getAttr<DLLExportAttr>();
3726 for (unsigned I = 0; I != NumParams; ++I) {
3727 (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), Ctor,
3728 Ctor->getParamDecl(I));
3729 S.DiscardCleanupsInEvaluationContext();
3733 /// \brief Instantiate the definition of the given function from its
3736 /// \param PointOfInstantiation the point at which the instantiation was
3737 /// required. Note that this is not precisely a "point of instantiation"
3738 /// for the function, but it's close.
3740 /// \param Function the already-instantiated declaration of a
3741 /// function template specialization or member function of a class template
3744 /// \param Recursive if true, recursively instantiates any functions that
3745 /// are required by this instantiation.
3747 /// \param DefinitionRequired if true, then we are performing an explicit
3748 /// instantiation where the body of the function is required. Complain if
3749 /// there is no such body.
3750 void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
3751 FunctionDecl *Function,
3753 bool DefinitionRequired,
3755 if (Function->isInvalidDecl() || Function->isDefined())
3758 // Never instantiate an explicit specialization except if it is a class scope
3759 // explicit specialization.
3760 TemplateSpecializationKind TSK = Function->getTemplateSpecializationKind();
3761 if (TSK == TSK_ExplicitSpecialization &&
3762 !Function->getClassScopeSpecializationPattern())
3765 // Find the function body that we'll be substituting.
3766 const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
3767 assert(PatternDecl && "instantiating a non-template");
3769 const FunctionDecl *PatternDef = PatternDecl->getDefinition();
3770 Stmt *Pattern = nullptr;
3772 Pattern = PatternDef->getBody(PatternDef);
3773 PatternDecl = PatternDef;
3774 if (PatternDef->willHaveBody())
3775 PatternDef = nullptr;
3778 // FIXME: We need to track the instantiation stack in order to know which
3779 // definitions should be visible within this instantiation.
3780 if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Function,
3781 Function->getInstantiatedFromMemberFunction(),
3782 PatternDecl, PatternDef, TSK,
3783 /*Complain*/DefinitionRequired)) {
3784 if (DefinitionRequired)
3785 Function->setInvalidDecl();
3786 else if (TSK == TSK_ExplicitInstantiationDefinition) {
3787 // Try again at the end of the translation unit (at which point a
3788 // definition will be required).
3790 Function->setInstantiationIsPending(true);
3791 PendingInstantiations.push_back(
3792 std::make_pair(Function, PointOfInstantiation));
3793 } else if (TSK == TSK_ImplicitInstantiation) {
3794 if (AtEndOfTU && !getDiagnostics().hasErrorOccurred()) {
3795 Diag(PointOfInstantiation, diag::warn_func_template_missing)
3797 Diag(PatternDecl->getLocation(), diag::note_forward_template_decl);
3798 if (getLangOpts().CPlusPlus11)
3799 Diag(PointOfInstantiation, diag::note_inst_declaration_hint)
3807 // Postpone late parsed template instantiations.
3808 if (PatternDecl->isLateTemplateParsed() &&
3809 !LateTemplateParser) {
3810 Function->setInstantiationIsPending(true);
3811 PendingInstantiations.push_back(
3812 std::make_pair(Function, PointOfInstantiation));
3816 // If we're performing recursive template instantiation, create our own
3817 // queue of pending implicit instantiations that we will instantiate later,
3818 // while we're still within our own instantiation context.
3819 // This has to happen before LateTemplateParser below is called, so that
3820 // it marks vtables used in late parsed templates as used.
3821 GlobalEagerInstantiationScope GlobalInstantiations(*this,
3822 /*Enabled=*/Recursive);
3823 LocalEagerInstantiationScope LocalInstantiations(*this);
3825 // Call the LateTemplateParser callback if there is a need to late parse
3826 // a templated function definition.
3827 if (!Pattern && PatternDecl->isLateTemplateParsed() &&
3828 LateTemplateParser) {
3829 // FIXME: Optimize to allow individual templates to be deserialized.
3830 if (PatternDecl->isFromASTFile())
3831 ExternalSource->ReadLateParsedTemplates(LateParsedTemplateMap);
3833 auto LPTIter = LateParsedTemplateMap.find(PatternDecl);
3834 assert(LPTIter != LateParsedTemplateMap.end() &&
3835 "missing LateParsedTemplate");
3836 LateTemplateParser(OpaqueParser, *LPTIter->second);
3837 Pattern = PatternDecl->getBody(PatternDecl);
3840 // Note, we should never try to instantiate a deleted function template.
3841 assert((Pattern || PatternDecl->isDefaulted()) &&
3842 "unexpected kind of function template definition");
3844 // C++1y [temp.explicit]p10:
3845 // Except for inline functions, declarations with types deduced from their
3846 // initializer or return value, and class template specializations, other
3847 // explicit instantiation declarations have the effect of suppressing the
3848 // implicit instantiation of the entity to which they refer.
3849 if (TSK == TSK_ExplicitInstantiationDeclaration &&
3850 !PatternDecl->isInlined() &&
3851 !PatternDecl->getReturnType()->getContainedAutoType())
3854 if (PatternDecl->isInlined()) {
3855 // Function, and all later redeclarations of it (from imported modules,
3856 // for instance), are now implicitly inline.
3857 for (auto *D = Function->getMostRecentDecl(); /**/;
3858 D = D->getPreviousDecl()) {
3859 D->setImplicitlyInline();
3865 InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
3866 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
3868 PrettyDeclStackTraceEntry CrashInfo(*this, Function, SourceLocation(),
3869 "instantiating function definition");
3871 // The instantiation is visible here, even if it was first declared in an
3872 // unimported module.
3873 Function->setVisibleDespiteOwningModule();
3875 // Copy the inner loc start from the pattern.
3876 Function->setInnerLocStart(PatternDecl->getInnerLocStart());
3878 EnterExpressionEvaluationContext EvalContext(
3879 *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
3881 // Introduce a new scope where local variable instantiations will be
3882 // recorded, unless we're actually a member function within a local
3883 // class, in which case we need to merge our results with the parent
3884 // scope (of the enclosing function).
3885 bool MergeWithParentScope = false;
3886 if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
3887 MergeWithParentScope = Rec->isLocalClass();
3889 LocalInstantiationScope Scope(*this, MergeWithParentScope);
3891 if (PatternDecl->isDefaulted())
3892 SetDeclDefaulted(Function, PatternDecl->getLocation());
3894 MultiLevelTemplateArgumentList TemplateArgs =
3895 getTemplateInstantiationArgs(Function, nullptr, false, PatternDecl);
3897 // Substitute into the qualifier; we can get a substitution failure here
3898 // through evil use of alias templates.
3899 // FIXME: Is CurContext correct for this? Should we go to the (instantiation
3900 // of the) lexical context of the pattern?
3901 SubstQualifier(*this, PatternDecl, Function, TemplateArgs);
3903 ActOnStartOfFunctionDef(nullptr, Function);
3905 // Enter the scope of this instantiation. We don't use
3906 // PushDeclContext because we don't have a scope.
3907 Sema::ContextRAII savedContext(*this, Function);
3909 if (addInstantiatedParametersToScope(*this, Function, PatternDecl, Scope,
3913 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Function)) {
3914 // If this is a constructor, instantiate the member initializers.
3915 InstantiateMemInitializers(Ctor, cast<CXXConstructorDecl>(PatternDecl),
3918 // If this is an MS ABI dllexport default constructor, instantiate any
3919 // default arguments.
3920 if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
3921 Ctor->isDefaultConstructor()) {
3922 InstantiateDefaultCtorDefaultArgs(*this, Ctor);
3926 // Instantiate the function body.
3927 StmtResult Body = SubstStmt(Pattern, TemplateArgs);
3929 if (Body.isInvalid())
3930 Function->setInvalidDecl();
3932 // FIXME: finishing the function body while in an expression evaluation
3933 // context seems wrong. Investigate more.
3934 ActOnFinishFunctionBody(Function, Body.get(),
3935 /*IsInstantiation=*/true);
3937 PerformDependentDiagnostics(PatternDecl, TemplateArgs);
3939 if (auto *Listener = getASTMutationListener())
3940 Listener->FunctionDefinitionInstantiated(Function);
3945 DeclGroupRef DG(Function);
3946 Consumer.HandleTopLevelDecl(DG);
3948 // This class may have local implicit instantiations that need to be
3949 // instantiation within this scope.
3950 LocalInstantiations.perform();
3952 GlobalInstantiations.perform();
3955 VarTemplateSpecializationDecl *Sema::BuildVarTemplateInstantiation(
3956 VarTemplateDecl *VarTemplate, VarDecl *FromVar,
3957 const TemplateArgumentList &TemplateArgList,
3958 const TemplateArgumentListInfo &TemplateArgsInfo,
3959 SmallVectorImpl<TemplateArgument> &Converted,
3960 SourceLocation PointOfInstantiation, void *InsertPos,
3961 LateInstantiatedAttrVec *LateAttrs,
3962 LocalInstantiationScope *StartingScope) {
3963 if (FromVar->isInvalidDecl())
3966 InstantiatingTemplate Inst(*this, PointOfInstantiation, FromVar);
3967 if (Inst.isInvalid())
3970 MultiLevelTemplateArgumentList TemplateArgLists;
3971 TemplateArgLists.addOuterTemplateArguments(&TemplateArgList);
3973 // Instantiate the first declaration of the variable template: for a partial
3974 // specialization of a static data member template, the first declaration may
3975 // or may not be the declaration in the class; if it's in the class, we want
3976 // to instantiate a member in the class (a declaration), and if it's outside,
3977 // we want to instantiate a definition.
3979 // If we're instantiating an explicitly-specialized member template or member
3980 // partial specialization, don't do this. The member specialization completely
3981 // replaces the original declaration in this case.
3982 bool IsMemberSpec = false;
3983 if (VarTemplatePartialSpecializationDecl *PartialSpec =
3984 dyn_cast<VarTemplatePartialSpecializationDecl>(FromVar))
3985 IsMemberSpec = PartialSpec->isMemberSpecialization();
3986 else if (VarTemplateDecl *FromTemplate = FromVar->getDescribedVarTemplate())
3987 IsMemberSpec = FromTemplate->isMemberSpecialization();
3989 FromVar = FromVar->getFirstDecl();
3991 MultiLevelTemplateArgumentList MultiLevelList(TemplateArgList);
3992 TemplateDeclInstantiator Instantiator(*this, FromVar->getDeclContext(),
3995 // TODO: Set LateAttrs and StartingScope ...
3997 return cast_or_null<VarTemplateSpecializationDecl>(
3998 Instantiator.VisitVarTemplateSpecializationDecl(
3999 VarTemplate, FromVar, InsertPos, TemplateArgsInfo, Converted));
4002 /// \brief Instantiates a variable template specialization by completing it
4003 /// with appropriate type information and initializer.
4004 VarTemplateSpecializationDecl *Sema::CompleteVarTemplateSpecializationDecl(
4005 VarTemplateSpecializationDecl *VarSpec, VarDecl *PatternDecl,
4006 const MultiLevelTemplateArgumentList &TemplateArgs) {
4008 // Do substitution on the type of the declaration
4009 TypeSourceInfo *DI =
4010 SubstType(PatternDecl->getTypeSourceInfo(), TemplateArgs,
4011 PatternDecl->getTypeSpecStartLoc(), PatternDecl->getDeclName());
4015 // Update the type of this variable template specialization.
4016 VarSpec->setType(DI->getType());
4018 // Instantiate the initializer.
4019 InstantiateVariableInitializer(VarSpec, PatternDecl, TemplateArgs);
4024 /// BuildVariableInstantiation - Used after a new variable has been created.
4025 /// Sets basic variable data and decides whether to postpone the
4026 /// variable instantiation.
4027 void Sema::BuildVariableInstantiation(
4028 VarDecl *NewVar, VarDecl *OldVar,
4029 const MultiLevelTemplateArgumentList &TemplateArgs,
4030 LateInstantiatedAttrVec *LateAttrs, DeclContext *Owner,
4031 LocalInstantiationScope *StartingScope,
4032 bool InstantiatingVarTemplate) {
4034 // If we are instantiating a local extern declaration, the
4035 // instantiation belongs lexically to the containing function.
4036 // If we are instantiating a static data member defined
4037 // out-of-line, the instantiation will have the same lexical
4038 // context (which will be a namespace scope) as the template.
4039 if (OldVar->isLocalExternDecl()) {
4040 NewVar->setLocalExternDecl();
4041 NewVar->setLexicalDeclContext(Owner);
4042 } else if (OldVar->isOutOfLine())
4043 NewVar->setLexicalDeclContext(OldVar->getLexicalDeclContext());
4044 NewVar->setTSCSpec(OldVar->getTSCSpec());
4045 NewVar->setInitStyle(OldVar->getInitStyle());
4046 NewVar->setCXXForRangeDecl(OldVar->isCXXForRangeDecl());
4047 NewVar->setConstexpr(OldVar->isConstexpr());
4048 NewVar->setInitCapture(OldVar->isInitCapture());
4049 NewVar->setPreviousDeclInSameBlockScope(
4050 OldVar->isPreviousDeclInSameBlockScope());
4051 NewVar->setAccess(OldVar->getAccess());
4053 if (!OldVar->isStaticDataMember()) {
4054 if (OldVar->isUsed(false))
4055 NewVar->setIsUsed();
4056 NewVar->setReferenced(OldVar->isReferenced());
4059 InstantiateAttrs(TemplateArgs, OldVar, NewVar, LateAttrs, StartingScope);
4061 LookupResult Previous(
4062 *this, NewVar->getDeclName(), NewVar->getLocation(),
4063 NewVar->isLocalExternDecl() ? Sema::LookupRedeclarationWithLinkage
4064 : Sema::LookupOrdinaryName,
4065 Sema::ForRedeclaration);
4067 if (NewVar->isLocalExternDecl() && OldVar->getPreviousDecl() &&
4068 (!OldVar->getPreviousDecl()->getDeclContext()->isDependentContext() ||
4069 OldVar->getPreviousDecl()->getDeclContext()==OldVar->getDeclContext())) {
4070 // We have a previous declaration. Use that one, so we merge with the
4072 if (NamedDecl *NewPrev = FindInstantiatedDecl(
4073 NewVar->getLocation(), OldVar->getPreviousDecl(), TemplateArgs))
4074 Previous.addDecl(NewPrev);
4075 } else if (!isa<VarTemplateSpecializationDecl>(NewVar) &&
4076 OldVar->hasLinkage())
4077 LookupQualifiedName(Previous, NewVar->getDeclContext(), false);
4078 CheckVariableDeclaration(NewVar, Previous);
4080 if (!InstantiatingVarTemplate) {
4081 NewVar->getLexicalDeclContext()->addHiddenDecl(NewVar);
4082 if (!NewVar->isLocalExternDecl() || !NewVar->getPreviousDecl())
4083 NewVar->getDeclContext()->makeDeclVisibleInContext(NewVar);
4086 if (!OldVar->isOutOfLine()) {
4087 if (NewVar->getDeclContext()->isFunctionOrMethod())
4088 CurrentInstantiationScope->InstantiatedLocal(OldVar, NewVar);
4091 // Link instantiations of static data members back to the template from
4092 // which they were instantiated.
4093 if (NewVar->isStaticDataMember() && !InstantiatingVarTemplate)
4094 NewVar->setInstantiationOfStaticDataMember(OldVar,
4095 TSK_ImplicitInstantiation);
4097 // Forward the mangling number from the template to the instantiated decl.
4098 Context.setManglingNumber(NewVar, Context.getManglingNumber(OldVar));
4099 Context.setStaticLocalNumber(NewVar, Context.getStaticLocalNumber(OldVar));
4101 // Delay instantiation of the initializer for variable templates or inline
4102 // static data members until a definition of the variable is needed. We need
4103 // it right away if the type contains 'auto'.
4104 if ((!isa<VarTemplateSpecializationDecl>(NewVar) &&
4105 !InstantiatingVarTemplate &&
4106 !(OldVar->isInline() && OldVar->isThisDeclarationADefinition())) ||
4107 NewVar->getType()->isUndeducedType())
4108 InstantiateVariableInitializer(NewVar, OldVar, TemplateArgs);
4110 // Diagnose unused local variables with dependent types, where the diagnostic
4111 // will have been deferred.
4112 if (!NewVar->isInvalidDecl() &&
4113 NewVar->getDeclContext()->isFunctionOrMethod() &&
4114 OldVar->getType()->isDependentType())
4115 DiagnoseUnusedDecl(NewVar);
4118 /// \brief Instantiate the initializer of a variable.
4119 void Sema::InstantiateVariableInitializer(
4120 VarDecl *Var, VarDecl *OldVar,
4121 const MultiLevelTemplateArgumentList &TemplateArgs) {
4122 // We propagate the 'inline' flag with the initializer, because it
4123 // would otherwise imply that the variable is a definition for a
4124 // non-static data member.
4125 if (OldVar->isInlineSpecified())
4126 Var->setInlineSpecified();
4127 else if (OldVar->isInline())
4128 Var->setImplicitlyInline();
4130 if (OldVar->getInit()) {
4131 if (Var->isStaticDataMember() && !OldVar->isOutOfLine())
4132 PushExpressionEvaluationContext(
4133 Sema::ExpressionEvaluationContext::ConstantEvaluated, OldVar);
4135 PushExpressionEvaluationContext(
4136 Sema::ExpressionEvaluationContext::PotentiallyEvaluated, OldVar);
4138 // Instantiate the initializer.
4142 ContextRAII SwitchContext(*this, Var->getDeclContext());
4143 Init = SubstInitializer(OldVar->getInit(), TemplateArgs,
4144 OldVar->getInitStyle() == VarDecl::CallInit);
4147 if (!Init.isInvalid()) {
4148 Expr *InitExpr = Init.get();
4150 if (Var->hasAttr<DLLImportAttr>() &&
4152 !InitExpr->isConstantInitializer(getASTContext(), false))) {
4153 // Do not dynamically initialize dllimport variables.
4154 } else if (InitExpr) {
4155 bool DirectInit = OldVar->isDirectInit();
4156 AddInitializerToDecl(Var, InitExpr, DirectInit);
4158 ActOnUninitializedDecl(Var);
4160 // FIXME: Not too happy about invalidating the declaration
4161 // because of a bogus initializer.
4162 Var->setInvalidDecl();
4165 PopExpressionEvaluationContext();
4167 if (Var->isStaticDataMember()) {
4168 if (!Var->isOutOfLine())
4171 // If the declaration inside the class had an initializer, don't add
4172 // another one to the out-of-line definition.
4173 if (OldVar->getFirstDecl()->hasInit())
4177 // We'll add an initializer to a for-range declaration later.
4178 if (Var->isCXXForRangeDecl())
4181 ActOnUninitializedDecl(Var);
4185 /// \brief Instantiate the definition of the given variable from its
4188 /// \param PointOfInstantiation the point at which the instantiation was
4189 /// required. Note that this is not precisely a "point of instantiation"
4190 /// for the function, but it's close.
4192 /// \param Var the already-instantiated declaration of a static member
4193 /// variable of a class template specialization.
4195 /// \param Recursive if true, recursively instantiates any functions that
4196 /// are required by this instantiation.
4198 /// \param DefinitionRequired if true, then we are performing an explicit
4199 /// instantiation where an out-of-line definition of the member variable
4200 /// is required. Complain if there is no such definition.
4201 void Sema::InstantiateStaticDataMemberDefinition(
4202 SourceLocation PointOfInstantiation,
4205 bool DefinitionRequired) {
4206 InstantiateVariableDefinition(PointOfInstantiation, Var, Recursive,
4207 DefinitionRequired);
4210 void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
4211 VarDecl *Var, bool Recursive,
4212 bool DefinitionRequired, bool AtEndOfTU) {
4213 if (Var->isInvalidDecl())
4216 VarTemplateSpecializationDecl *VarSpec =
4217 dyn_cast<VarTemplateSpecializationDecl>(Var);
4218 VarDecl *PatternDecl = nullptr, *Def = nullptr;
4219 MultiLevelTemplateArgumentList TemplateArgs =
4220 getTemplateInstantiationArgs(Var);
4223 // If this is a variable template specialization, make sure that it is
4224 // non-dependent, then find its instantiation pattern.
4225 bool InstantiationDependent = false;
4226 assert(!TemplateSpecializationType::anyDependentTemplateArguments(
4227 VarSpec->getTemplateArgsInfo(), InstantiationDependent) &&
4228 "Only instantiate variable template specializations that are "
4229 "not type-dependent");
4230 (void)InstantiationDependent;
4232 // Find the variable initialization that we'll be substituting. If the
4233 // pattern was instantiated from a member template, look back further to
4234 // find the real pattern.
4235 assert(VarSpec->getSpecializedTemplate() &&
4236 "Specialization without specialized template?");
4237 llvm::PointerUnion<VarTemplateDecl *,
4238 VarTemplatePartialSpecializationDecl *> PatternPtr =
4239 VarSpec->getSpecializedTemplateOrPartial();
4240 if (PatternPtr.is<VarTemplatePartialSpecializationDecl *>()) {
4241 VarTemplatePartialSpecializationDecl *Tmpl =
4242 PatternPtr.get<VarTemplatePartialSpecializationDecl *>();
4243 while (VarTemplatePartialSpecializationDecl *From =
4244 Tmpl->getInstantiatedFromMember()) {
4245 if (Tmpl->isMemberSpecialization())
4252 VarTemplateDecl *Tmpl = PatternPtr.get<VarTemplateDecl *>();
4253 while (VarTemplateDecl *From =
4254 Tmpl->getInstantiatedFromMemberTemplate()) {
4255 if (Tmpl->isMemberSpecialization())
4260 PatternDecl = Tmpl->getTemplatedDecl();
4263 // If this is a static data member template, there might be an
4264 // uninstantiated initializer on the declaration. If so, instantiate
4266 if (PatternDecl->isStaticDataMember() &&
4267 (PatternDecl = PatternDecl->getFirstDecl())->hasInit() &&
4269 // FIXME: Factor out the duplicated instantiation context setup/tear down
4271 InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
4272 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
4274 PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
4275 "instantiating variable initializer");
4277 // The instantiation is visible here, even if it was first declared in an
4278 // unimported module.
4279 Var->setVisibleDespiteOwningModule();
4281 // If we're performing recursive template instantiation, create our own
4282 // queue of pending implicit instantiations that we will instantiate
4283 // later, while we're still within our own instantiation context.
4284 GlobalEagerInstantiationScope GlobalInstantiations(*this,
4285 /*Enabled=*/Recursive);
4286 LocalInstantiationScope Local(*this);
4287 LocalEagerInstantiationScope LocalInstantiations(*this);
4289 // Enter the scope of this instantiation. We don't use
4290 // PushDeclContext because we don't have a scope.
4291 ContextRAII PreviousContext(*this, Var->getDeclContext());
4292 InstantiateVariableInitializer(Var, PatternDecl, TemplateArgs);
4293 PreviousContext.pop();
4295 // This variable may have local implicit instantiations that need to be
4296 // instantiated within this scope.
4297 LocalInstantiations.perform();
4299 GlobalInstantiations.perform();
4302 // Find actual definition
4303 Def = PatternDecl->getDefinition(getASTContext());
4305 // If this is a static data member, find its out-of-line definition.
4306 assert(Var->isStaticDataMember() && "not a static data member?");
4307 PatternDecl = Var->getInstantiatedFromStaticDataMember();
4309 assert(PatternDecl && "data member was not instantiated from a template?");
4310 assert(PatternDecl->isStaticDataMember() && "not a static data member?");
4311 Def = PatternDecl->getDefinition();
4314 TemplateSpecializationKind TSK = Var->getTemplateSpecializationKind();
4316 // If we don't have a definition of the variable template, we won't perform
4317 // any instantiation. Rather, we rely on the user to instantiate this
4318 // definition (or provide a specialization for it) in another translation
4320 if (!Def && !DefinitionRequired) {
4321 if (TSK == TSK_ExplicitInstantiationDefinition) {
4322 PendingInstantiations.push_back(
4323 std::make_pair(Var, PointOfInstantiation));
4324 } else if (TSK == TSK_ImplicitInstantiation) {
4325 // Warn about missing definition at the end of translation unit.
4326 if (AtEndOfTU && !getDiagnostics().hasErrorOccurred()) {
4327 Diag(PointOfInstantiation, diag::warn_var_template_missing)
4329 Diag(PatternDecl->getLocation(), diag::note_forward_template_decl);
4330 if (getLangOpts().CPlusPlus11)
4331 Diag(PointOfInstantiation, diag::note_inst_declaration_hint) << Var;
4338 // FIXME: We need to track the instantiation stack in order to know which
4339 // definitions should be visible within this instantiation.
4340 // FIXME: Produce diagnostics when Var->getInstantiatedFromStaticDataMember().
4341 if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Var,
4342 /*InstantiatedFromMember*/false,
4343 PatternDecl, Def, TSK,
4344 /*Complain*/DefinitionRequired))
4348 // Never instantiate an explicit specialization.
4349 if (TSK == TSK_ExplicitSpecialization)
4352 // C++11 [temp.explicit]p10:
4353 // Except for inline functions, [...] explicit instantiation declarations
4354 // have the effect of suppressing the implicit instantiation of the entity
4355 // to which they refer.
4356 if (TSK == TSK_ExplicitInstantiationDeclaration)
4359 // Make sure to pass the instantiated variable to the consumer at the end.
4360 struct PassToConsumerRAII {
4361 ASTConsumer &Consumer;
4364 PassToConsumerRAII(ASTConsumer &Consumer, VarDecl *Var)
4365 : Consumer(Consumer), Var(Var) { }
4367 ~PassToConsumerRAII() {
4368 Consumer.HandleCXXStaticMemberVarInstantiation(Var);
4370 } PassToConsumerRAII(Consumer, Var);
4372 // If we already have a definition, we're done.
4373 if (VarDecl *Def = Var->getDefinition()) {
4374 // We may be explicitly instantiating something we've already implicitly
4376 Def->setTemplateSpecializationKind(Var->getTemplateSpecializationKind(),
4377 PointOfInstantiation);
4381 InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
4382 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
4384 PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
4385 "instantiating variable definition");
4387 // If we're performing recursive template instantiation, create our own
4388 // queue of pending implicit instantiations that we will instantiate later,
4389 // while we're still within our own instantiation context.
4390 GlobalEagerInstantiationScope GlobalInstantiations(*this,
4391 /*Enabled=*/Recursive);
4393 // Enter the scope of this instantiation. We don't use
4394 // PushDeclContext because we don't have a scope.
4395 ContextRAII PreviousContext(*this, Var->getDeclContext());
4396 LocalInstantiationScope Local(*this);
4398 LocalEagerInstantiationScope LocalInstantiations(*this);
4400 VarDecl *OldVar = Var;
4401 if (Def->isStaticDataMember() && !Def->isOutOfLine()) {
4402 // We're instantiating an inline static data member whose definition was
4403 // provided inside the class.
4404 InstantiateVariableInitializer(Var, Def, TemplateArgs);
4405 } else if (!VarSpec) {
4406 Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
4408 } else if (Var->isStaticDataMember() &&
4409 Var->getLexicalDeclContext()->isRecord()) {
4410 // We need to instantiate the definition of a static data member template,
4411 // and all we have is the in-class declaration of it. Instantiate a separate
4412 // declaration of the definition.
4413 TemplateDeclInstantiator Instantiator(*this, Var->getDeclContext(),
4415 Var = cast_or_null<VarDecl>(Instantiator.VisitVarTemplateSpecializationDecl(
4416 VarSpec->getSpecializedTemplate(), Def, nullptr,
4417 VarSpec->getTemplateArgsInfo(), VarSpec->getTemplateArgs().asArray()));
4419 llvm::PointerUnion<VarTemplateDecl *,
4420 VarTemplatePartialSpecializationDecl *> PatternPtr =
4421 VarSpec->getSpecializedTemplateOrPartial();
4422 if (VarTemplatePartialSpecializationDecl *Partial =
4423 PatternPtr.dyn_cast<VarTemplatePartialSpecializationDecl *>())
4424 cast<VarTemplateSpecializationDecl>(Var)->setInstantiationOf(
4425 Partial, &VarSpec->getTemplateInstantiationArgs());
4427 // Merge the definition with the declaration.
4428 LookupResult R(*this, Var->getDeclName(), Var->getLocation(),
4429 LookupOrdinaryName, ForRedeclaration);
4431 MergeVarDecl(Var, R);
4433 // Attach the initializer.
4434 InstantiateVariableInitializer(Var, Def, TemplateArgs);
4437 // Complete the existing variable's definition with an appropriately
4438 // substituted type and initializer.
4439 Var = CompleteVarTemplateSpecializationDecl(VarSpec, Def, TemplateArgs);
4441 PreviousContext.pop();
4444 PassToConsumerRAII.Var = Var;
4445 Var->setTemplateSpecializationKind(OldVar->getTemplateSpecializationKind(),
4446 OldVar->getPointOfInstantiation());
4449 // This variable may have local implicit instantiations that need to be
4450 // instantiated within this scope.
4451 LocalInstantiations.perform();
4453 GlobalInstantiations.perform();
4457 Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
4458 const CXXConstructorDecl *Tmpl,
4459 const MultiLevelTemplateArgumentList &TemplateArgs) {
4461 SmallVector<CXXCtorInitializer*, 4> NewInits;
4462 bool AnyErrors = Tmpl->isInvalidDecl();
4464 // Instantiate all the initializers.
4465 for (const auto *Init : Tmpl->inits()) {
4466 // Only instantiate written initializers, let Sema re-construct implicit
4468 if (!Init->isWritten())
4471 SourceLocation EllipsisLoc;
4473 if (Init->isPackExpansion()) {
4474 // This is a pack expansion. We should expand it now.
4475 TypeLoc BaseTL = Init->getTypeSourceInfo()->getTypeLoc();
4476 SmallVector<UnexpandedParameterPack, 4> Unexpanded;
4477 collectUnexpandedParameterPacks(BaseTL, Unexpanded);
4478 collectUnexpandedParameterPacks(Init->getInit(), Unexpanded);
4479 bool ShouldExpand = false;
4480 bool RetainExpansion = false;
4481 Optional<unsigned> NumExpansions;
4482 if (CheckParameterPacksForExpansion(Init->getEllipsisLoc(),
4483 BaseTL.getSourceRange(),
4485 TemplateArgs, ShouldExpand,
4489 New->setInvalidDecl();
4492 assert(ShouldExpand && "Partial instantiation of base initializer?");
4494 // Loop over all of the arguments in the argument pack(s),
4495 for (unsigned I = 0; I != *NumExpansions; ++I) {
4496 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, I);
4498 // Instantiate the initializer.
4499 ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs,
4500 /*CXXDirectInit=*/true);
4501 if (TempInit.isInvalid()) {
4506 // Instantiate the base type.
4507 TypeSourceInfo *BaseTInfo = SubstType(Init->getTypeSourceInfo(),
4509 Init->getSourceLocation(),
4510 New->getDeclName());
4516 // Build the initializer.
4517 MemInitResult NewInit = BuildBaseInitializer(BaseTInfo->getType(),
4518 BaseTInfo, TempInit.get(),
4521 if (NewInit.isInvalid()) {
4526 NewInits.push_back(NewInit.get());
4532 // Instantiate the initializer.
4533 ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs,
4534 /*CXXDirectInit=*/true);
4535 if (TempInit.isInvalid()) {
4540 MemInitResult NewInit;
4541 if (Init->isDelegatingInitializer() || Init->isBaseInitializer()) {
4542 TypeSourceInfo *TInfo = SubstType(Init->getTypeSourceInfo(),
4544 Init->getSourceLocation(),
4545 New->getDeclName());
4548 New->setInvalidDecl();
4552 if (Init->isBaseInitializer())
4553 NewInit = BuildBaseInitializer(TInfo->getType(), TInfo, TempInit.get(),
4554 New->getParent(), EllipsisLoc);
4556 NewInit = BuildDelegatingInitializer(TInfo, TempInit.get(),
4557 cast<CXXRecordDecl>(CurContext->getParent()));
4558 } else if (Init->isMemberInitializer()) {
4559 FieldDecl *Member = cast_or_null<FieldDecl>(FindInstantiatedDecl(
4560 Init->getMemberLocation(),
4565 New->setInvalidDecl();
4569 NewInit = BuildMemberInitializer(Member, TempInit.get(),
4570 Init->getSourceLocation());
4571 } else if (Init->isIndirectMemberInitializer()) {
4572 IndirectFieldDecl *IndirectMember =
4573 cast_or_null<IndirectFieldDecl>(FindInstantiatedDecl(
4574 Init->getMemberLocation(),
4575 Init->getIndirectMember(), TemplateArgs));
4577 if (!IndirectMember) {
4579 New->setInvalidDecl();
4583 NewInit = BuildMemberInitializer(IndirectMember, TempInit.get(),
4584 Init->getSourceLocation());
4587 if (NewInit.isInvalid()) {
4589 New->setInvalidDecl();
4591 NewInits.push_back(NewInit.get());
4595 // Assign all the initializers to the new constructor.
4596 ActOnMemInitializers(New,
4597 /*FIXME: ColonLoc */
4603 // TODO: this could be templated if the various decl types used the
4604 // same method name.
4605 static bool isInstantiationOf(ClassTemplateDecl *Pattern,
4606 ClassTemplateDecl *Instance) {
4607 Pattern = Pattern->getCanonicalDecl();
4610 Instance = Instance->getCanonicalDecl();
4611 if (Pattern == Instance) return true;
4612 Instance = Instance->getInstantiatedFromMemberTemplate();
4618 static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
4619 FunctionTemplateDecl *Instance) {
4620 Pattern = Pattern->getCanonicalDecl();
4623 Instance = Instance->getCanonicalDecl();
4624 if (Pattern == Instance) return true;
4625 Instance = Instance->getInstantiatedFromMemberTemplate();
4632 isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
4633 ClassTemplatePartialSpecializationDecl *Instance) {
4635 = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
4637 Instance = cast<ClassTemplatePartialSpecializationDecl>(
4638 Instance->getCanonicalDecl());
4639 if (Pattern == Instance)
4641 Instance = Instance->getInstantiatedFromMember();
4647 static bool isInstantiationOf(CXXRecordDecl *Pattern,
4648 CXXRecordDecl *Instance) {
4649 Pattern = Pattern->getCanonicalDecl();
4652 Instance = Instance->getCanonicalDecl();
4653 if (Pattern == Instance) return true;
4654 Instance = Instance->getInstantiatedFromMemberClass();
4660 static bool isInstantiationOf(FunctionDecl *Pattern,
4661 FunctionDecl *Instance) {
4662 Pattern = Pattern->getCanonicalDecl();
4665 Instance = Instance->getCanonicalDecl();
4666 if (Pattern == Instance) return true;
4667 Instance = Instance->getInstantiatedFromMemberFunction();
4673 static bool isInstantiationOf(EnumDecl *Pattern,
4674 EnumDecl *Instance) {
4675 Pattern = Pattern->getCanonicalDecl();
4678 Instance = Instance->getCanonicalDecl();
4679 if (Pattern == Instance) return true;
4680 Instance = Instance->getInstantiatedFromMemberEnum();
4686 static bool isInstantiationOf(UsingShadowDecl *Pattern,
4687 UsingShadowDecl *Instance,
4689 return declaresSameEntity(C.getInstantiatedFromUsingShadowDecl(Instance),
4693 static bool isInstantiationOf(UsingDecl *Pattern, UsingDecl *Instance,
4695 return declaresSameEntity(C.getInstantiatedFromUsingDecl(Instance), Pattern);
4698 template<typename T>
4699 static bool isInstantiationOfUnresolvedUsingDecl(T *Pattern, Decl *Other,
4701 // An unresolved using declaration can instantiate to an unresolved using
4702 // declaration, or to a using declaration or a using declaration pack.
4704 // Multiple declarations can claim to be instantiated from an unresolved
4705 // using declaration if it's a pack expansion. We want the UsingPackDecl
4706 // in that case, not the individual UsingDecls within the pack.
4707 bool OtherIsPackExpansion;
4708 NamedDecl *OtherFrom;
4709 if (auto *OtherUUD = dyn_cast<T>(Other)) {
4710 OtherIsPackExpansion = OtherUUD->isPackExpansion();
4711 OtherFrom = Ctx.getInstantiatedFromUsingDecl(OtherUUD);
4712 } else if (auto *OtherUPD = dyn_cast<UsingPackDecl>(Other)) {
4713 OtherIsPackExpansion = true;
4714 OtherFrom = OtherUPD->getInstantiatedFromUsingDecl();
4715 } else if (auto *OtherUD = dyn_cast<UsingDecl>(Other)) {
4716 OtherIsPackExpansion = false;
4717 OtherFrom = Ctx.getInstantiatedFromUsingDecl(OtherUD);
4721 return Pattern->isPackExpansion() == OtherIsPackExpansion &&
4722 declaresSameEntity(OtherFrom, Pattern);
4725 static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
4726 VarDecl *Instance) {
4727 assert(Instance->isStaticDataMember());
4729 Pattern = Pattern->getCanonicalDecl();
4732 Instance = Instance->getCanonicalDecl();
4733 if (Pattern == Instance) return true;
4734 Instance = Instance->getInstantiatedFromStaticDataMember();
4740 // Other is the prospective instantiation
4741 // D is the prospective pattern
4742 static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
4743 if (auto *UUD = dyn_cast<UnresolvedUsingTypenameDecl>(D))
4744 return isInstantiationOfUnresolvedUsingDecl(UUD, Other, Ctx);
4746 if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(D))
4747 return isInstantiationOfUnresolvedUsingDecl(UUD, Other, Ctx);
4749 if (D->getKind() != Other->getKind())
4752 if (auto *Record = dyn_cast<CXXRecordDecl>(Other))
4753 return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
4755 if (auto *Function = dyn_cast<FunctionDecl>(Other))
4756 return isInstantiationOf(cast<FunctionDecl>(D), Function);
4758 if (auto *Enum = dyn_cast<EnumDecl>(Other))
4759 return isInstantiationOf(cast<EnumDecl>(D), Enum);
4761 if (auto *Var = dyn_cast<VarDecl>(Other))
4762 if (Var->isStaticDataMember())
4763 return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
4765 if (auto *Temp = dyn_cast<ClassTemplateDecl>(Other))
4766 return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
4768 if (auto *Temp = dyn_cast<FunctionTemplateDecl>(Other))
4769 return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
4771 if (auto *PartialSpec =
4772 dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
4773 return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
4776 if (auto *Field = dyn_cast<FieldDecl>(Other)) {
4777 if (!Field->getDeclName()) {
4778 // This is an unnamed field.
4779 return declaresSameEntity(Ctx.getInstantiatedFromUnnamedFieldDecl(Field),
4780 cast<FieldDecl>(D));
4784 if (auto *Using = dyn_cast<UsingDecl>(Other))
4785 return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
4787 if (auto *Shadow = dyn_cast<UsingShadowDecl>(Other))
4788 return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
4790 return D->getDeclName() &&
4791 D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
4794 template<typename ForwardIterator>
4795 static NamedDecl *findInstantiationOf(ASTContext &Ctx,
4797 ForwardIterator first,
4798 ForwardIterator last) {
4799 for (; first != last; ++first)
4800 if (isInstantiationOf(Ctx, D, *first))
4801 return cast<NamedDecl>(*first);
4806 /// \brief Finds the instantiation of the given declaration context
4807 /// within the current instantiation.
4809 /// \returns NULL if there was an error
4810 DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
4811 const MultiLevelTemplateArgumentList &TemplateArgs) {
4812 if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
4813 Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs, true);
4814 return cast_or_null<DeclContext>(ID);
4818 /// \brief Find the instantiation of the given declaration within the
4819 /// current instantiation.
4821 /// This routine is intended to be used when \p D is a declaration
4822 /// referenced from within a template, that needs to mapped into the
4823 /// corresponding declaration within an instantiation. For example,
4827 /// template<typename T>
4830 /// KnownValue = sizeof(T)
4833 /// bool getKind() const { return KnownValue; }
4836 /// template struct X<int>;
4839 /// In the instantiation of <tt>X<int>::getKind()</tt>, we need to map the
4840 /// \p EnumConstantDecl for \p KnownValue (which refers to
4841 /// <tt>X<T>::<Kind>::KnownValue</tt>) to its instantiation
4842 /// (<tt>X<int>::<Kind>::KnownValue</tt>). \p FindInstantiatedDecl performs
4843 /// this mapping from within the instantiation of <tt>X<int></tt>.
4844 NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
4845 const MultiLevelTemplateArgumentList &TemplateArgs,
4846 bool FindingInstantiatedContext) {
4847 DeclContext *ParentDC = D->getDeclContext();
4848 // FIXME: Parmeters of pointer to functions (y below) that are themselves
4849 // parameters (p below) can have their ParentDC set to the translation-unit
4850 // - thus we can not consistently check if the ParentDC of such a parameter
4851 // is Dependent or/and a FunctionOrMethod.
4852 // For e.g. this code, during Template argument deduction tries to
4853 // find an instantiated decl for (T y) when the ParentDC for y is
4854 // the translation unit.
4855 // e.g. template <class T> void Foo(auto (*p)(T y) -> decltype(y())) {}
4856 // float baz(float(*)()) { return 0.0; }
4858 // The better fix here is perhaps to ensure that a ParmVarDecl, by the time
4859 // it gets here, always has a FunctionOrMethod as its ParentDC??
4861 // - as long as we have a ParmVarDecl whose parent is non-dependent and
4862 // whose type is not instantiation dependent, do nothing to the decl
4863 // - otherwise find its instantiated decl.
4864 if (isa<ParmVarDecl>(D) && !ParentDC->isDependentContext() &&
4865 !cast<ParmVarDecl>(D)->getType()->isInstantiationDependentType())
4867 if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
4868 isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
4869 (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext()) ||
4870 (isa<CXXRecordDecl>(D) && cast<CXXRecordDecl>(D)->isLambda())) {
4871 // D is a local of some kind. Look into the map of local
4872 // declarations to their instantiations.
4873 if (CurrentInstantiationScope) {
4874 if (auto Found = CurrentInstantiationScope->findInstantiationOf(D)) {
4875 if (Decl *FD = Found->dyn_cast<Decl *>())
4876 return cast<NamedDecl>(FD);
4878 int PackIdx = ArgumentPackSubstitutionIndex;
4879 assert(PackIdx != -1 &&
4880 "found declaration pack but not pack expanding");
4881 typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack;
4882 return cast<NamedDecl>((*Found->get<DeclArgumentPack *>())[PackIdx]);
4886 // If we're performing a partial substitution during template argument
4887 // deduction, we may not have values for template parameters yet. They
4888 // just map to themselves.
4889 if (isa<NonTypeTemplateParmDecl>(D) || isa<TemplateTypeParmDecl>(D) ||
4890 isa<TemplateTemplateParmDecl>(D))
4893 if (D->isInvalidDecl())
4896 // Normally this function only searches for already instantiated declaration
4897 // however we have to make an exclusion for local types used before
4898 // definition as in the code:
4900 // template<typename T> void f1() {
4901 // void g1(struct x1);
4905 // In this case instantiation of the type of 'g1' requires definition of
4906 // 'x1', which is defined later. Error recovery may produce an enum used
4907 // before definition. In these cases we need to instantiate relevant
4908 // declarations here.
4909 bool NeedInstantiate = false;
4910 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D))
4911 NeedInstantiate = RD->isLocalClass();
4913 NeedInstantiate = isa<EnumDecl>(D);
4914 if (NeedInstantiate) {
4915 Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
4916 CurrentInstantiationScope->InstantiatedLocal(D, Inst);
4917 return cast<TypeDecl>(Inst);
4920 // If we didn't find the decl, then we must have a label decl that hasn't
4921 // been found yet. Lazily instantiate it and return it now.
4922 assert(isa<LabelDecl>(D));
4924 Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
4925 assert(Inst && "Failed to instantiate label??");
4927 CurrentInstantiationScope->InstantiatedLocal(D, Inst);
4928 return cast<LabelDecl>(Inst);
4931 // For variable template specializations, update those that are still
4933 if (VarTemplateSpecializationDecl *VarSpec =
4934 dyn_cast<VarTemplateSpecializationDecl>(D)) {
4935 bool InstantiationDependent = false;
4936 const TemplateArgumentListInfo &VarTemplateArgs =
4937 VarSpec->getTemplateArgsInfo();
4938 if (TemplateSpecializationType::anyDependentTemplateArguments(
4939 VarTemplateArgs, InstantiationDependent))
4940 D = cast<NamedDecl>(
4941 SubstDecl(D, VarSpec->getDeclContext(), TemplateArgs));
4945 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
4946 if (!Record->isDependentContext())
4949 // Determine whether this record is the "templated" declaration describing
4950 // a class template or class template partial specialization.
4951 ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
4953 ClassTemplate = ClassTemplate->getCanonicalDecl();
4954 else if (ClassTemplatePartialSpecializationDecl *PartialSpec
4955 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record))
4956 ClassTemplate = PartialSpec->getSpecializedTemplate()->getCanonicalDecl();
4958 // Walk the current context to find either the record or an instantiation of
4960 DeclContext *DC = CurContext;
4961 while (!DC->isFileContext()) {
4962 // If we're performing substitution while we're inside the template
4963 // definition, we'll find our own context. We're done.
4964 if (DC->Equals(Record))
4967 if (CXXRecordDecl *InstRecord = dyn_cast<CXXRecordDecl>(DC)) {
4968 // Check whether we're in the process of instantiating a class template
4969 // specialization of the template we're mapping.
4970 if (ClassTemplateSpecializationDecl *InstSpec
4971 = dyn_cast<ClassTemplateSpecializationDecl>(InstRecord)){
4972 ClassTemplateDecl *SpecTemplate = InstSpec->getSpecializedTemplate();
4973 if (ClassTemplate && isInstantiationOf(ClassTemplate, SpecTemplate))
4977 // Check whether we're in the process of instantiating a member class.
4978 if (isInstantiationOf(Record, InstRecord))
4982 // Move to the outer template scope.
4983 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) {
4984 if (FD->getFriendObjectKind() && FD->getDeclContext()->isFileContext()){
4985 DC = FD->getLexicalDeclContext();
4988 // An implicit deduction guide acts as if it's within the class template
4989 // specialization described by its name and first N template params.
4990 auto *Guide = dyn_cast<CXXDeductionGuideDecl>(FD);
4991 if (Guide && Guide->isImplicit()) {
4992 TemplateDecl *TD = Guide->getDeducedTemplate();
4993 // Convert the arguments to an "as-written" list.
4994 TemplateArgumentListInfo Args(Loc, Loc);
4995 for (TemplateArgument Arg : TemplateArgs.getInnermost().take_front(
4996 TD->getTemplateParameters()->size())) {
4997 ArrayRef<TemplateArgument> Unpacked(Arg);
4998 if (Arg.getKind() == TemplateArgument::Pack)
4999 Unpacked = Arg.pack_elements();
5000 for (TemplateArgument UnpackedArg : Unpacked)
5002 getTrivialTemplateArgumentLoc(UnpackedArg, QualType(), Loc));
5004 QualType T = CheckTemplateIdType(TemplateName(TD), Loc, Args);
5007 auto *SubstRecord = T->getAsCXXRecordDecl();
5008 assert(SubstRecord && "class template id not a class type?");
5009 // Check that this template-id names the primary template and not a
5010 // partial or explicit specialization. (In the latter cases, it's
5011 // meaningless to attempt to find an instantiation of D within the
5013 // FIXME: The standard doesn't say what should happen here.
5014 if (FindingInstantiatedContext &&
5015 usesPartialOrExplicitSpecialization(
5016 Loc, cast<ClassTemplateSpecializationDecl>(SubstRecord))) {
5017 Diag(Loc, diag::err_specialization_not_primary_template)
5018 << T << (SubstRecord->getTemplateSpecializationKind() ==
5019 TSK_ExplicitSpecialization);
5027 DC = DC->getParent();
5030 // Fall through to deal with other dependent record types (e.g.,
5031 // anonymous unions in class templates).
5034 if (!ParentDC->isDependentContext())
5037 ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
5041 if (ParentDC != D->getDeclContext()) {
5042 // We performed some kind of instantiation in the parent context,
5043 // so now we need to look into the instantiated parent context to
5044 // find the instantiation of the declaration D.
5046 // If our context used to be dependent, we may need to instantiate
5047 // it before performing lookup into that context.
5048 bool IsBeingInstantiated = false;
5049 if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
5050 if (!Spec->isDependentContext()) {
5051 QualType T = Context.getTypeDeclType(Spec);
5052 const RecordType *Tag = T->getAs<RecordType>();
5053 assert(Tag && "type of non-dependent record is not a RecordType");
5054 if (Tag->isBeingDefined())
5055 IsBeingInstantiated = true;
5056 if (!Tag->isBeingDefined() &&
5057 RequireCompleteType(Loc, T, diag::err_incomplete_type))
5060 ParentDC = Tag->getDecl();
5064 NamedDecl *Result = nullptr;
5065 // FIXME: If the name is a dependent name, this lookup won't necessarily
5066 // find it. Does that ever matter?
5067 if (auto Name = D->getDeclName()) {
5068 DeclarationNameInfo NameInfo(Name, D->getLocation());
5069 Name = SubstDeclarationNameInfo(NameInfo, TemplateArgs).getName();
5072 DeclContext::lookup_result Found = ParentDC->lookup(Name);
5073 Result = findInstantiationOf(Context, D, Found.begin(), Found.end());
5075 // Since we don't have a name for the entity we're looking for,
5076 // our only option is to walk through all of the declarations to
5077 // find that name. This will occur in a few cases:
5079 // - anonymous struct/union within a template
5080 // - unnamed class/struct/union/enum within a template
5082 // FIXME: Find a better way to find these instantiations!
5083 Result = findInstantiationOf(Context, D,
5084 ParentDC->decls_begin(),
5085 ParentDC->decls_end());
5089 if (isa<UsingShadowDecl>(D)) {
5090 // UsingShadowDecls can instantiate to nothing because of using hiding.
5091 } else if (Diags.hasErrorOccurred()) {
5092 // We've already complained about something, so most likely this
5093 // declaration failed to instantiate. There's no point in complaining
5094 // further, since this is normal in invalid code.
5095 } else if (IsBeingInstantiated) {
5096 // The class in which this member exists is currently being
5097 // instantiated, and we haven't gotten around to instantiating this
5098 // member yet. This can happen when the code uses forward declarations
5099 // of member classes, and introduces ordering dependencies via
5100 // template instantiation.
5101 Diag(Loc, diag::err_member_not_yet_instantiated)
5103 << Context.getTypeDeclType(cast<CXXRecordDecl>(ParentDC));
5104 Diag(D->getLocation(), diag::note_non_instantiated_member_here);
5105 } else if (EnumConstantDecl *ED = dyn_cast<EnumConstantDecl>(D)) {
5106 // This enumeration constant was found when the template was defined,
5107 // but can't be found in the instantiation. This can happen if an
5108 // unscoped enumeration member is explicitly specialized.
5109 EnumDecl *Enum = cast<EnumDecl>(ED->getLexicalDeclContext());
5110 EnumDecl *Spec = cast<EnumDecl>(FindInstantiatedDecl(Loc, Enum,
5112 assert(Spec->getTemplateSpecializationKind() ==
5113 TSK_ExplicitSpecialization);
5114 Diag(Loc, diag::err_enumerator_does_not_exist)
5116 << Context.getTypeDeclType(cast<TypeDecl>(Spec->getDeclContext()));
5117 Diag(Spec->getLocation(), diag::note_enum_specialized_here)
5118 << Context.getTypeDeclType(Spec);
5120 // We should have found something, but didn't.
5121 llvm_unreachable("Unable to find instantiation of declaration!");
5131 /// \brief Performs template instantiation for all implicit template
5132 /// instantiations we have seen until this point.
5133 void Sema::PerformPendingInstantiations(bool LocalOnly) {
5134 while (!PendingLocalImplicitInstantiations.empty() ||
5135 (!LocalOnly && !PendingInstantiations.empty())) {
5136 PendingImplicitInstantiation Inst;
5138 if (PendingLocalImplicitInstantiations.empty()) {
5139 Inst = PendingInstantiations.front();
5140 PendingInstantiations.pop_front();
5142 Inst = PendingLocalImplicitInstantiations.front();
5143 PendingLocalImplicitInstantiations.pop_front();
5146 // Instantiate function definitions
5147 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
5148 bool DefinitionRequired = Function->getTemplateSpecializationKind() ==
5149 TSK_ExplicitInstantiationDefinition;
5150 InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true,
5151 DefinitionRequired, true);
5152 if (Function->isDefined())
5153 Function->setInstantiationIsPending(false);
5157 // Instantiate variable definitions
5158 VarDecl *Var = cast<VarDecl>(Inst.first);
5160 assert((Var->isStaticDataMember() ||
5161 isa<VarTemplateSpecializationDecl>(Var)) &&
5162 "Not a static data member, nor a variable template"
5163 " specialization?");
5165 // Don't try to instantiate declarations if the most recent redeclaration
5167 if (Var->getMostRecentDecl()->isInvalidDecl())
5170 // Check if the most recent declaration has changed the specialization kind
5171 // and removed the need for implicit instantiation.
5172 switch (Var->getMostRecentDecl()->getTemplateSpecializationKind()) {
5173 case TSK_Undeclared:
5174 llvm_unreachable("Cannot instantitiate an undeclared specialization.");
5175 case TSK_ExplicitInstantiationDeclaration:
5176 case TSK_ExplicitSpecialization:
5177 continue; // No longer need to instantiate this type.
5178 case TSK_ExplicitInstantiationDefinition:
5179 // We only need an instantiation if the pending instantiation *is* the
5180 // explicit instantiation.
5181 if (Var != Var->getMostRecentDecl()) continue;
5182 case TSK_ImplicitInstantiation:
5186 PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
5187 "instantiating variable definition");
5188 bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
5189 TSK_ExplicitInstantiationDefinition;
5191 // Instantiate static data member definitions or variable template
5193 InstantiateVariableDefinition(/*FIXME:*/ Inst.second, Var, true,
5194 DefinitionRequired, true);
5198 void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
5199 const MultiLevelTemplateArgumentList &TemplateArgs) {
5200 for (auto DD : Pattern->ddiags()) {
5201 switch (DD->getKind()) {
5202 case DependentDiagnostic::Access:
5203 HandleDependentAccessCheck(*DD, TemplateArgs);