1 //===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //===----------------------------------------------------------------------===/
9 // This file implements C++ template instantiation for declarations.
11 //===----------------------------------------------------------------------===/
12 #include "clang/Sema/SemaInternal.h"
13 #include "clang/AST/ASTConsumer.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/ASTMutationListener.h"
16 #include "clang/AST/DeclTemplate.h"
17 #include "clang/AST/DeclVisitor.h"
18 #include "clang/AST/DependentDiagnostic.h"
19 #include "clang/AST/Expr.h"
20 #include "clang/AST/ExprCXX.h"
21 #include "clang/AST/TypeLoc.h"
22 #include "clang/Sema/Initialization.h"
23 #include "clang/Sema/Lookup.h"
24 #include "clang/Sema/PrettyDeclStackTrace.h"
25 #include "clang/Sema/Template.h"
27 using namespace clang;
29 static bool isDeclWithinFunction(const Decl *D) {
30 const DeclContext *DC = D->getDeclContext();
31 if (DC->isFunctionOrMethod())
35 return cast<CXXRecordDecl>(DC)->isLocalClass();
40 template<typename DeclT>
41 static bool SubstQualifier(Sema &SemaRef, const DeclT *OldDecl, DeclT *NewDecl,
42 const MultiLevelTemplateArgumentList &TemplateArgs) {
43 if (!OldDecl->getQualifierLoc())
46 assert((NewDecl->getFriendObjectKind() ||
47 !OldDecl->getLexicalDeclContext()->isDependentContext()) &&
48 "non-friend with qualified name defined in dependent context");
49 Sema::ContextRAII SavedContext(
51 const_cast<DeclContext *>(NewDecl->getFriendObjectKind()
52 ? NewDecl->getLexicalDeclContext()
53 : OldDecl->getLexicalDeclContext()));
55 NestedNameSpecifierLoc NewQualifierLoc
56 = SemaRef.SubstNestedNameSpecifierLoc(OldDecl->getQualifierLoc(),
62 NewDecl->setQualifierInfo(NewQualifierLoc);
66 bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl,
67 DeclaratorDecl *NewDecl) {
68 return ::SubstQualifier(SemaRef, OldDecl, NewDecl, TemplateArgs);
71 bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl,
73 return ::SubstQualifier(SemaRef, OldDecl, NewDecl, TemplateArgs);
76 // Include attribute instantiation code.
77 #include "clang/Sema/AttrTemplateInstantiate.inc"
79 static void instantiateDependentAlignedAttr(
80 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
81 const AlignedAttr *Aligned, Decl *New, bool IsPackExpansion) {
82 if (Aligned->isAlignmentExpr()) {
83 // The alignment expression is a constant expression.
84 EnterExpressionEvaluationContext Unevaluated(
85 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
86 ExprResult Result = S.SubstExpr(Aligned->getAlignmentExpr(), TemplateArgs);
87 if (!Result.isInvalid())
88 S.AddAlignedAttr(Aligned->getLocation(), New, Result.getAs<Expr>(),
89 Aligned->getSpellingListIndex(), IsPackExpansion);
91 TypeSourceInfo *Result = S.SubstType(Aligned->getAlignmentType(),
92 TemplateArgs, Aligned->getLocation(),
95 S.AddAlignedAttr(Aligned->getLocation(), New, Result,
96 Aligned->getSpellingListIndex(), IsPackExpansion);
100 static void instantiateDependentAlignedAttr(
101 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
102 const AlignedAttr *Aligned, Decl *New) {
103 if (!Aligned->isPackExpansion()) {
104 instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
108 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
109 if (Aligned->isAlignmentExpr())
110 S.collectUnexpandedParameterPacks(Aligned->getAlignmentExpr(),
113 S.collectUnexpandedParameterPacks(Aligned->getAlignmentType()->getTypeLoc(),
115 assert(!Unexpanded.empty() && "Pack expansion without parameter packs?");
117 // Determine whether we can expand this attribute pack yet.
118 bool Expand = true, RetainExpansion = false;
119 Optional<unsigned> NumExpansions;
120 // FIXME: Use the actual location of the ellipsis.
121 SourceLocation EllipsisLoc = Aligned->getLocation();
122 if (S.CheckParameterPacksForExpansion(EllipsisLoc, Aligned->getRange(),
123 Unexpanded, TemplateArgs, Expand,
124 RetainExpansion, NumExpansions))
128 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, -1);
129 instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, true);
131 for (unsigned I = 0; I != *NumExpansions; ++I) {
132 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, I);
133 instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
138 static void instantiateDependentAssumeAlignedAttr(
139 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
140 const AssumeAlignedAttr *Aligned, Decl *New) {
141 // The alignment expression is a constant expression.
142 EnterExpressionEvaluationContext Unevaluated(
143 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
145 Expr *E, *OE = nullptr;
146 ExprResult Result = S.SubstExpr(Aligned->getAlignment(), TemplateArgs);
147 if (Result.isInvalid())
149 E = Result.getAs<Expr>();
151 if (Aligned->getOffset()) {
152 Result = S.SubstExpr(Aligned->getOffset(), TemplateArgs);
153 if (Result.isInvalid())
155 OE = Result.getAs<Expr>();
158 S.AddAssumeAlignedAttr(Aligned->getLocation(), New, E, OE,
159 Aligned->getSpellingListIndex());
162 static void instantiateDependentAlignValueAttr(
163 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
164 const AlignValueAttr *Aligned, Decl *New) {
165 // The alignment expression is a constant expression.
166 EnterExpressionEvaluationContext Unevaluated(
167 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
168 ExprResult Result = S.SubstExpr(Aligned->getAlignment(), TemplateArgs);
169 if (!Result.isInvalid())
170 S.AddAlignValueAttr(Aligned->getLocation(), New, Result.getAs<Expr>(),
171 Aligned->getSpellingListIndex());
174 static void instantiateDependentAllocAlignAttr(
175 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
176 const AllocAlignAttr *Align, Decl *New) {
177 Expr *Param = IntegerLiteral::Create(
178 S.getASTContext(), llvm::APInt(64, Align->getParamIndex()),
179 S.getASTContext().UnsignedLongLongTy, Align->getLocation());
180 S.AddAllocAlignAttr(Align->getLocation(), New, Param,
181 Align->getSpellingListIndex());
184 static Expr *instantiateDependentFunctionAttrCondition(
185 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
186 const Attr *A, Expr *OldCond, const Decl *Tmpl, FunctionDecl *New) {
187 Expr *Cond = nullptr;
189 Sema::ContextRAII SwitchContext(S, New);
190 EnterExpressionEvaluationContext Unevaluated(
191 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
192 ExprResult Result = S.SubstExpr(OldCond, TemplateArgs);
193 if (Result.isInvalid())
195 Cond = Result.getAs<Expr>();
197 if (!Cond->isTypeDependent()) {
198 ExprResult Converted = S.PerformContextuallyConvertToBool(Cond);
199 if (Converted.isInvalid())
201 Cond = Converted.get();
204 SmallVector<PartialDiagnosticAt, 8> Diags;
205 if (OldCond->isValueDependent() && !Cond->isValueDependent() &&
206 !Expr::isPotentialConstantExprUnevaluated(Cond, New, Diags)) {
207 S.Diag(A->getLocation(), diag::err_attr_cond_never_constant_expr) << A;
208 for (const auto &P : Diags)
209 S.Diag(P.first, P.second);
215 static void instantiateDependentEnableIfAttr(
216 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
217 const EnableIfAttr *EIA, const Decl *Tmpl, FunctionDecl *New) {
218 Expr *Cond = instantiateDependentFunctionAttrCondition(
219 S, TemplateArgs, EIA, EIA->getCond(), Tmpl, New);
222 New->addAttr(new (S.getASTContext()) EnableIfAttr(
223 EIA->getLocation(), S.getASTContext(), Cond, EIA->getMessage(),
224 EIA->getSpellingListIndex()));
227 static void instantiateDependentDiagnoseIfAttr(
228 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
229 const DiagnoseIfAttr *DIA, const Decl *Tmpl, FunctionDecl *New) {
230 Expr *Cond = instantiateDependentFunctionAttrCondition(
231 S, TemplateArgs, DIA, DIA->getCond(), Tmpl, New);
234 New->addAttr(new (S.getASTContext()) DiagnoseIfAttr(
235 DIA->getLocation(), S.getASTContext(), Cond, DIA->getMessage(),
236 DIA->getDiagnosticType(), DIA->getArgDependent(), New,
237 DIA->getSpellingListIndex()));
240 // Constructs and adds to New a new instance of CUDALaunchBoundsAttr using
241 // template A as the base and arguments from TemplateArgs.
242 static void instantiateDependentCUDALaunchBoundsAttr(
243 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
244 const CUDALaunchBoundsAttr &Attr, Decl *New) {
245 // The alignment expression is a constant expression.
246 EnterExpressionEvaluationContext Unevaluated(
247 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
249 ExprResult Result = S.SubstExpr(Attr.getMaxThreads(), TemplateArgs);
250 if (Result.isInvalid())
252 Expr *MaxThreads = Result.getAs<Expr>();
254 Expr *MinBlocks = nullptr;
255 if (Attr.getMinBlocks()) {
256 Result = S.SubstExpr(Attr.getMinBlocks(), TemplateArgs);
257 if (Result.isInvalid())
259 MinBlocks = Result.getAs<Expr>();
262 S.AddLaunchBoundsAttr(Attr.getLocation(), New, MaxThreads, MinBlocks,
263 Attr.getSpellingListIndex());
267 instantiateDependentModeAttr(Sema &S,
268 const MultiLevelTemplateArgumentList &TemplateArgs,
269 const ModeAttr &Attr, Decl *New) {
270 S.AddModeAttr(Attr.getRange(), New, Attr.getMode(),
271 Attr.getSpellingListIndex(), /*InInstantiation=*/true);
274 /// Instantiation of 'declare simd' attribute and its arguments.
275 static void instantiateOMPDeclareSimdDeclAttr(
276 Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
277 const OMPDeclareSimdDeclAttr &Attr, Decl *New) {
278 // Allow 'this' in clauses with varlists.
279 if (auto *FTD = dyn_cast<FunctionTemplateDecl>(New))
280 New = FTD->getTemplatedDecl();
281 auto *FD = cast<FunctionDecl>(New);
282 auto *ThisContext = dyn_cast_or_null<CXXRecordDecl>(FD->getDeclContext());
283 SmallVector<Expr *, 4> Uniforms, Aligneds, Alignments, Linears, Steps;
284 SmallVector<unsigned, 4> LinModifiers;
286 auto &&Subst = [&](Expr *E) -> ExprResult {
287 if (auto *DRE = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()))
288 if (auto *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl())) {
289 Sema::ContextRAII SavedContext(S, FD);
290 LocalInstantiationScope Local(S);
291 if (FD->getNumParams() > PVD->getFunctionScopeIndex())
292 Local.InstantiatedLocal(
293 PVD, FD->getParamDecl(PVD->getFunctionScopeIndex()));
294 return S.SubstExpr(E, TemplateArgs);
296 Sema::CXXThisScopeRAII ThisScope(S, ThisContext, /*TypeQuals=*/0,
297 FD->isCXXInstanceMember());
298 return S.SubstExpr(E, TemplateArgs);
302 if (auto *E = Attr.getSimdlen())
305 if (Attr.uniforms_size() > 0) {
306 for(auto *E : Attr.uniforms()) {
307 ExprResult Inst = Subst(E);
308 if (Inst.isInvalid())
310 Uniforms.push_back(Inst.get());
314 auto AI = Attr.alignments_begin();
315 for (auto *E : Attr.aligneds()) {
316 ExprResult Inst = Subst(E);
317 if (Inst.isInvalid())
319 Aligneds.push_back(Inst.get());
322 Inst = S.SubstExpr(*AI, TemplateArgs);
323 Alignments.push_back(Inst.get());
327 auto SI = Attr.steps_begin();
328 for (auto *E : Attr.linears()) {
329 ExprResult Inst = Subst(E);
330 if (Inst.isInvalid())
332 Linears.push_back(Inst.get());
335 Inst = S.SubstExpr(*SI, TemplateArgs);
336 Steps.push_back(Inst.get());
339 LinModifiers.append(Attr.modifiers_begin(), Attr.modifiers_end());
340 (void)S.ActOnOpenMPDeclareSimdDirective(
341 S.ConvertDeclToDeclGroup(New), Attr.getBranchState(), Simdlen.get(),
342 Uniforms, Aligneds, Alignments, Linears, LinModifiers, Steps,
346 static bool DeclContainsAttr(const Decl *D, const Attr *NewAttr) {
347 if (!D->hasAttrs() || NewAttr->duplicatesAllowed())
349 return llvm::find_if(D->getAttrs(), [NewAttr](const Attr *Attr) {
350 return Attr->getKind() == NewAttr->getKind();
351 }) != D->getAttrs().end();
354 void Sema::InstantiateAttrsForDecl(
355 const MultiLevelTemplateArgumentList &TemplateArgs, const Decl *Tmpl,
356 Decl *New, LateInstantiatedAttrVec *LateAttrs,
357 LocalInstantiationScope *OuterMostScope) {
358 if (NamedDecl *ND = dyn_cast<NamedDecl>(New)) {
359 for (const auto *TmplAttr : Tmpl->attrs()) {
360 // FIXME: If any of the special case versions from InstantiateAttrs become
361 // applicable to template declaration, we'll need to add them here.
362 CXXThisScopeRAII ThisScope(
363 *this, dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext()),
364 /*TypeQuals*/ 0, ND->isCXXInstanceMember());
366 Attr *NewAttr = sema::instantiateTemplateAttributeForDecl(
367 TmplAttr, Context, *this, TemplateArgs);
368 if (NewAttr && !DeclContainsAttr(New, NewAttr))
369 New->addAttr(NewAttr);
374 void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
375 const Decl *Tmpl, Decl *New,
376 LateInstantiatedAttrVec *LateAttrs,
377 LocalInstantiationScope *OuterMostScope) {
378 for (const auto *TmplAttr : Tmpl->attrs()) {
379 // FIXME: This should be generalized to more than just the AlignedAttr.
380 const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr);
381 if (Aligned && Aligned->isAlignmentDependent()) {
382 instantiateDependentAlignedAttr(*this, TemplateArgs, Aligned, New);
386 const AssumeAlignedAttr *AssumeAligned = dyn_cast<AssumeAlignedAttr>(TmplAttr);
388 instantiateDependentAssumeAlignedAttr(*this, TemplateArgs, AssumeAligned, New);
392 const AlignValueAttr *AlignValue = dyn_cast<AlignValueAttr>(TmplAttr);
394 instantiateDependentAlignValueAttr(*this, TemplateArgs, AlignValue, New);
398 if (const auto *AllocAlign = dyn_cast<AllocAlignAttr>(TmplAttr)) {
399 instantiateDependentAllocAlignAttr(*this, TemplateArgs, AllocAlign, New);
404 if (const auto *EnableIf = dyn_cast<EnableIfAttr>(TmplAttr)) {
405 instantiateDependentEnableIfAttr(*this, TemplateArgs, EnableIf, Tmpl,
406 cast<FunctionDecl>(New));
410 if (const auto *DiagnoseIf = dyn_cast<DiagnoseIfAttr>(TmplAttr)) {
411 instantiateDependentDiagnoseIfAttr(*this, TemplateArgs, DiagnoseIf, Tmpl,
412 cast<FunctionDecl>(New));
416 if (const CUDALaunchBoundsAttr *CUDALaunchBounds =
417 dyn_cast<CUDALaunchBoundsAttr>(TmplAttr)) {
418 instantiateDependentCUDALaunchBoundsAttr(*this, TemplateArgs,
419 *CUDALaunchBounds, New);
423 if (const ModeAttr *Mode = dyn_cast<ModeAttr>(TmplAttr)) {
424 instantiateDependentModeAttr(*this, TemplateArgs, *Mode, New);
428 if (const auto *OMPAttr = dyn_cast<OMPDeclareSimdDeclAttr>(TmplAttr)) {
429 instantiateOMPDeclareSimdDeclAttr(*this, TemplateArgs, *OMPAttr, New);
433 // Existing DLL attribute on the instantiation takes precedence.
434 if (TmplAttr->getKind() == attr::DLLExport ||
435 TmplAttr->getKind() == attr::DLLImport) {
436 if (New->hasAttr<DLLExportAttr>() || New->hasAttr<DLLImportAttr>()) {
441 if (auto ABIAttr = dyn_cast<ParameterABIAttr>(TmplAttr)) {
442 AddParameterABIAttr(ABIAttr->getRange(), New, ABIAttr->getABI(),
443 ABIAttr->getSpellingListIndex());
447 if (isa<NSConsumedAttr>(TmplAttr) || isa<CFConsumedAttr>(TmplAttr)) {
448 AddNSConsumedAttr(TmplAttr->getRange(), New,
449 TmplAttr->getSpellingListIndex(),
450 isa<NSConsumedAttr>(TmplAttr),
451 /*template instantiation*/ true);
455 assert(!TmplAttr->isPackExpansion());
456 if (TmplAttr->isLateParsed() && LateAttrs) {
457 // Late parsed attributes must be instantiated and attached after the
458 // enclosing class has been instantiated. See Sema::InstantiateClass.
459 LocalInstantiationScope *Saved = nullptr;
460 if (CurrentInstantiationScope)
461 Saved = CurrentInstantiationScope->cloneScopes(OuterMostScope);
462 LateAttrs->push_back(LateInstantiatedAttribute(TmplAttr, Saved, New));
464 // Allow 'this' within late-parsed attributes.
465 NamedDecl *ND = dyn_cast<NamedDecl>(New);
466 CXXRecordDecl *ThisContext =
467 dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext());
468 CXXThisScopeRAII ThisScope(*this, ThisContext, /*TypeQuals*/0,
469 ND && ND->isCXXInstanceMember());
471 Attr *NewAttr = sema::instantiateTemplateAttribute(TmplAttr, Context,
472 *this, TemplateArgs);
474 if (NewAttr && !DeclContainsAttr(New, NewAttr))
475 New->addAttr(NewAttr);
480 /// Get the previous declaration of a declaration for the purposes of template
481 /// instantiation. If this finds a previous declaration, then the previous
482 /// declaration of the instantiation of D should be an instantiation of the
483 /// result of this function.
484 template<typename DeclT>
485 static DeclT *getPreviousDeclForInstantiation(DeclT *D) {
486 DeclT *Result = D->getPreviousDecl();
488 // If the declaration is within a class, and the previous declaration was
489 // merged from a different definition of that class, then we don't have a
490 // previous declaration for the purpose of template instantiation.
491 if (Result && isa<CXXRecordDecl>(D->getDeclContext()) &&
492 D->getLexicalDeclContext() != Result->getLexicalDeclContext())
499 TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
500 llvm_unreachable("Translation units cannot be instantiated");
504 TemplateDeclInstantiator::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
505 llvm_unreachable("pragma comment cannot be instantiated");
508 Decl *TemplateDeclInstantiator::VisitPragmaDetectMismatchDecl(
509 PragmaDetectMismatchDecl *D) {
510 llvm_unreachable("pragma comment cannot be instantiated");
514 TemplateDeclInstantiator::VisitExternCContextDecl(ExternCContextDecl *D) {
515 llvm_unreachable("extern \"C\" context cannot be instantiated");
519 TemplateDeclInstantiator::VisitLabelDecl(LabelDecl *D) {
520 LabelDecl *Inst = LabelDecl::Create(SemaRef.Context, Owner, D->getLocation(),
522 Owner->addDecl(Inst);
527 TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
528 llvm_unreachable("Namespaces cannot be instantiated");
532 TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
533 NamespaceAliasDecl *Inst
534 = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
535 D->getNamespaceLoc(),
538 D->getQualifierLoc(),
539 D->getTargetNameLoc(),
541 Owner->addDecl(Inst);
545 Decl *TemplateDeclInstantiator::InstantiateTypedefNameDecl(TypedefNameDecl *D,
547 bool Invalid = false;
548 TypeSourceInfo *DI = D->getTypeSourceInfo();
549 if (DI->getType()->isInstantiationDependentType() ||
550 DI->getType()->isVariablyModifiedType()) {
551 DI = SemaRef.SubstType(DI, TemplateArgs,
552 D->getLocation(), D->getDeclName());
555 DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
558 SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
561 // HACK: g++ has a bug where it gets the value kind of ?: wrong.
562 // libstdc++ relies upon this bug in its implementation of common_type.
563 // If we happen to be processing that implementation, fake up the g++ ?:
564 // semantics. See LWG issue 2141 for more information on the bug.
565 const DecltypeType *DT = DI->getType()->getAs<DecltypeType>();
566 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D->getDeclContext());
567 if (DT && RD && isa<ConditionalOperator>(DT->getUnderlyingExpr()) &&
568 DT->isReferenceType() &&
569 RD->getEnclosingNamespaceContext() == SemaRef.getStdNamespace() &&
570 RD->getIdentifier() && RD->getIdentifier()->isStr("common_type") &&
571 D->getIdentifier() && D->getIdentifier()->isStr("type") &&
572 SemaRef.getSourceManager().isInSystemHeader(D->getLocStart()))
573 // Fold it to the (non-reference) type which g++ would have produced.
574 DI = SemaRef.Context.getTrivialTypeSourceInfo(
575 DI->getType().getNonReferenceType());
577 // Create the new typedef
578 TypedefNameDecl *Typedef;
580 Typedef = TypeAliasDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
581 D->getLocation(), D->getIdentifier(), DI);
583 Typedef = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
584 D->getLocation(), D->getIdentifier(), DI);
586 Typedef->setInvalidDecl();
588 // If the old typedef was the name for linkage purposes of an anonymous
589 // tag decl, re-establish that relationship for the new typedef.
590 if (const TagType *oldTagType = D->getUnderlyingType()->getAs<TagType>()) {
591 TagDecl *oldTag = oldTagType->getDecl();
592 if (oldTag->getTypedefNameForAnonDecl() == D && !Invalid) {
593 TagDecl *newTag = DI->getType()->castAs<TagType>()->getDecl();
594 assert(!newTag->hasNameForLinkage());
595 newTag->setTypedefNameForAnonDecl(Typedef);
599 if (TypedefNameDecl *Prev = getPreviousDeclForInstantiation(D)) {
600 NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
605 TypedefNameDecl *InstPrevTypedef = cast<TypedefNameDecl>(InstPrev);
607 // If the typedef types are not identical, reject them.
608 SemaRef.isIncompatibleTypedef(InstPrevTypedef, Typedef);
610 Typedef->setPreviousDecl(InstPrevTypedef);
613 SemaRef.InstantiateAttrs(TemplateArgs, D, Typedef);
615 Typedef->setAccess(D->getAccess());
620 Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
621 Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/false);
623 Owner->addDecl(Typedef);
627 Decl *TemplateDeclInstantiator::VisitTypeAliasDecl(TypeAliasDecl *D) {
628 Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/true);
630 Owner->addDecl(Typedef);
635 TemplateDeclInstantiator::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
636 // Create a local instantiation scope for this type alias template, which
637 // will contain the instantiations of the template parameters.
638 LocalInstantiationScope Scope(SemaRef);
640 TemplateParameterList *TempParams = D->getTemplateParameters();
641 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
645 TypeAliasDecl *Pattern = D->getTemplatedDecl();
647 TypeAliasTemplateDecl *PrevAliasTemplate = nullptr;
648 if (getPreviousDeclForInstantiation<TypedefNameDecl>(Pattern)) {
649 DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
650 if (!Found.empty()) {
651 PrevAliasTemplate = dyn_cast<TypeAliasTemplateDecl>(Found.front());
655 TypeAliasDecl *AliasInst = cast_or_null<TypeAliasDecl>(
656 InstantiateTypedefNameDecl(Pattern, /*IsTypeAlias=*/true));
660 TypeAliasTemplateDecl *Inst
661 = TypeAliasTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
662 D->getDeclName(), InstParams, AliasInst);
663 AliasInst->setDescribedAliasTemplate(Inst);
664 if (PrevAliasTemplate)
665 Inst->setPreviousDecl(PrevAliasTemplate);
667 Inst->setAccess(D->getAccess());
669 if (!PrevAliasTemplate)
670 Inst->setInstantiatedFromMemberTemplate(D);
672 Owner->addDecl(Inst);
677 Decl *TemplateDeclInstantiator::VisitBindingDecl(BindingDecl *D) {
678 auto *NewBD = BindingDecl::Create(SemaRef.Context, Owner, D->getLocation(),
680 NewBD->setReferenced(D->isReferenced());
681 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewBD);
685 Decl *TemplateDeclInstantiator::VisitDecompositionDecl(DecompositionDecl *D) {
686 // Transform the bindings first.
687 SmallVector<BindingDecl*, 16> NewBindings;
688 for (auto *OldBD : D->bindings())
689 NewBindings.push_back(cast<BindingDecl>(VisitBindingDecl(OldBD)));
690 ArrayRef<BindingDecl*> NewBindingArray = NewBindings;
692 auto *NewDD = cast_or_null<DecompositionDecl>(
693 VisitVarDecl(D, /*InstantiatingVarTemplate=*/false, &NewBindingArray));
695 if (!NewDD || NewDD->isInvalidDecl())
696 for (auto *NewBD : NewBindings)
697 NewBD->setInvalidDecl();
702 Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
703 return VisitVarDecl(D, /*InstantiatingVarTemplate=*/false);
706 Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D,
707 bool InstantiatingVarTemplate,
708 ArrayRef<BindingDecl*> *Bindings) {
710 // Do substitution on the type of the declaration
711 TypeSourceInfo *DI = SemaRef.SubstType(
712 D->getTypeSourceInfo(), TemplateArgs, D->getTypeSpecStartLoc(),
713 D->getDeclName(), /*AllowDeducedTST*/true);
717 if (DI->getType()->isFunctionType()) {
718 SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
719 << D->isStaticDataMember() << DI->getType();
723 DeclContext *DC = Owner;
724 if (D->isLocalExternDecl())
725 SemaRef.adjustContextForLocalExternDecl(DC);
727 // Build the instantiated declaration.
730 Var = DecompositionDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
731 D->getLocation(), DI->getType(), DI,
732 D->getStorageClass(), *Bindings);
734 Var = VarDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
735 D->getLocation(), D->getIdentifier(), DI->getType(),
736 DI, D->getStorageClass());
738 // In ARC, infer 'retaining' for variables of retainable type.
739 if (SemaRef.getLangOpts().ObjCAutoRefCount &&
740 SemaRef.inferObjCARCLifetime(Var))
741 Var->setInvalidDecl();
743 // Substitute the nested name specifier, if any.
744 if (SubstQualifier(D, Var))
747 SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs, Owner,
748 StartingScope, InstantiatingVarTemplate);
750 if (D->isNRVOVariable()) {
751 QualType ReturnType = cast<FunctionDecl>(DC)->getReturnType();
752 if (SemaRef.isCopyElisionCandidate(ReturnType, Var, false))
753 Var->setNRVOVariable(true);
756 Var->setImplicit(D->isImplicit());
761 Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
763 = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
764 D->getAccessSpecifierLoc(), D->getColonLoc());
765 Owner->addHiddenDecl(AD);
769 Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
770 bool Invalid = false;
771 TypeSourceInfo *DI = D->getTypeSourceInfo();
772 if (DI->getType()->isInstantiationDependentType() ||
773 DI->getType()->isVariablyModifiedType()) {
774 DI = SemaRef.SubstType(DI, TemplateArgs,
775 D->getLocation(), D->getDeclName());
777 DI = D->getTypeSourceInfo();
779 } else if (DI->getType()->isFunctionType()) {
780 // C++ [temp.arg.type]p3:
781 // If a declaration acquires a function type through a type
782 // dependent on a template-parameter and this causes a
783 // declaration that does not use the syntactic form of a
784 // function declarator to have function type, the program is
786 SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
791 SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
794 Expr *BitWidth = D->getBitWidth();
798 // The bit-width expression is a constant expression.
799 EnterExpressionEvaluationContext Unevaluated(
800 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
802 ExprResult InstantiatedBitWidth
803 = SemaRef.SubstExpr(BitWidth, TemplateArgs);
804 if (InstantiatedBitWidth.isInvalid()) {
808 BitWidth = InstantiatedBitWidth.getAs<Expr>();
811 FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
813 cast<RecordDecl>(Owner),
817 D->getInClassInitStyle(),
818 D->getInnerLocStart(),
822 cast<Decl>(Owner)->setInvalidDecl();
826 SemaRef.InstantiateAttrs(TemplateArgs, D, Field, LateAttrs, StartingScope);
828 if (Field->hasAttrs())
829 SemaRef.CheckAlignasUnderalignment(Field);
832 Field->setInvalidDecl();
834 if (!Field->getDeclName()) {
835 // Keep track of where this decl came from.
836 SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D);
838 if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
839 if (Parent->isAnonymousStructOrUnion() &&
840 Parent->getRedeclContext()->isFunctionOrMethod())
841 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
844 Field->setImplicit(D->isImplicit());
845 Field->setAccess(D->getAccess());
846 Owner->addDecl(Field);
851 Decl *TemplateDeclInstantiator::VisitMSPropertyDecl(MSPropertyDecl *D) {
852 bool Invalid = false;
853 TypeSourceInfo *DI = D->getTypeSourceInfo();
855 if (DI->getType()->isVariablyModifiedType()) {
856 SemaRef.Diag(D->getLocation(), diag::err_property_is_variably_modified)
859 } else if (DI->getType()->isInstantiationDependentType()) {
860 DI = SemaRef.SubstType(DI, TemplateArgs,
861 D->getLocation(), D->getDeclName());
863 DI = D->getTypeSourceInfo();
865 } else if (DI->getType()->isFunctionType()) {
866 // C++ [temp.arg.type]p3:
867 // If a declaration acquires a function type through a type
868 // dependent on a template-parameter and this causes a
869 // declaration that does not use the syntactic form of a
870 // function declarator to have function type, the program is
872 SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
877 SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType());
880 MSPropertyDecl *Property = MSPropertyDecl::Create(
881 SemaRef.Context, Owner, D->getLocation(), D->getDeclName(), DI->getType(),
882 DI, D->getLocStart(), D->getGetterId(), D->getSetterId());
884 SemaRef.InstantiateAttrs(TemplateArgs, D, Property, LateAttrs,
888 Property->setInvalidDecl();
890 Property->setAccess(D->getAccess());
891 Owner->addDecl(Property);
896 Decl *TemplateDeclInstantiator::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
897 NamedDecl **NamedChain =
898 new (SemaRef.Context)NamedDecl*[D->getChainingSize()];
901 for (auto *PI : D->chain()) {
902 NamedDecl *Next = SemaRef.FindInstantiatedDecl(D->getLocation(), PI,
907 NamedChain[i++] = Next;
910 QualType T = cast<FieldDecl>(NamedChain[i-1])->getType();
911 IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
912 SemaRef.Context, Owner, D->getLocation(), D->getIdentifier(), T,
913 {NamedChain, D->getChainingSize()});
915 for (const auto *Attr : D->attrs())
916 IndirectField->addAttr(Attr->clone(SemaRef.Context));
918 IndirectField->setImplicit(D->isImplicit());
919 IndirectField->setAccess(D->getAccess());
920 Owner->addDecl(IndirectField);
921 return IndirectField;
924 Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
925 // Handle friend type expressions by simply substituting template
926 // parameters into the pattern type and checking the result.
927 if (TypeSourceInfo *Ty = D->getFriendType()) {
928 TypeSourceInfo *InstTy;
929 // If this is an unsupported friend, don't bother substituting template
930 // arguments into it. The actual type referred to won't be used by any
931 // parts of Clang, and may not be valid for instantiating. Just use the
932 // same info for the instantiated friend.
933 if (D->isUnsupportedFriend()) {
936 InstTy = SemaRef.SubstType(Ty, TemplateArgs,
937 D->getLocation(), DeclarationName());
942 FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getLocStart(),
943 D->getFriendLoc(), InstTy);
947 FD->setAccess(AS_public);
948 FD->setUnsupportedFriend(D->isUnsupportedFriend());
953 NamedDecl *ND = D->getFriendDecl();
954 assert(ND && "friend decl must be a decl or a type!");
956 // All of the Visit implementations for the various potential friend
957 // declarations have to be carefully written to work for friend
958 // objects, with the most important detail being that the target
959 // decl should almost certainly not be placed in Owner.
960 Decl *NewND = Visit(ND);
961 if (!NewND) return nullptr;
964 FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
965 cast<NamedDecl>(NewND), D->getFriendLoc());
966 FD->setAccess(AS_public);
967 FD->setUnsupportedFriend(D->isUnsupportedFriend());
972 Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
973 Expr *AssertExpr = D->getAssertExpr();
975 // The expression in a static assertion is a constant expression.
976 EnterExpressionEvaluationContext Unevaluated(
977 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
979 ExprResult InstantiatedAssertExpr
980 = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
981 if (InstantiatedAssertExpr.isInvalid())
984 return SemaRef.BuildStaticAssertDeclaration(D->getLocation(),
985 InstantiatedAssertExpr.get(),
991 Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
992 EnumDecl *PrevDecl = nullptr;
993 if (EnumDecl *PatternPrev = getPreviousDeclForInstantiation(D)) {
994 NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
997 if (!Prev) return nullptr;
998 PrevDecl = cast<EnumDecl>(Prev);
1001 EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner, D->getLocStart(),
1002 D->getLocation(), D->getIdentifier(),
1003 PrevDecl, D->isScoped(),
1004 D->isScopedUsingClassTag(), D->isFixed());
1006 if (TypeSourceInfo *TI = D->getIntegerTypeSourceInfo()) {
1007 // If we have type source information for the underlying type, it means it
1008 // has been explicitly set by the user. Perform substitution on it before
1010 SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
1011 TypeSourceInfo *NewTI = SemaRef.SubstType(TI, TemplateArgs, UnderlyingLoc,
1013 if (!NewTI || SemaRef.CheckEnumUnderlyingType(NewTI))
1014 Enum->setIntegerType(SemaRef.Context.IntTy);
1016 Enum->setIntegerTypeSourceInfo(NewTI);
1018 assert(!D->getIntegerType()->isDependentType()
1019 && "Dependent type without type source info");
1020 Enum->setIntegerType(D->getIntegerType());
1024 SemaRef.InstantiateAttrs(TemplateArgs, D, Enum);
1026 Enum->setInstantiationOfMemberEnum(D, TSK_ImplicitInstantiation);
1027 Enum->setAccess(D->getAccess());
1028 // Forward the mangling number from the template to the instantiated decl.
1029 SemaRef.Context.setManglingNumber(Enum, SemaRef.Context.getManglingNumber(D));
1030 // See if the old tag was defined along with a declarator.
1031 // If it did, mark the new tag as being associated with that declarator.
1032 if (DeclaratorDecl *DD = SemaRef.Context.getDeclaratorForUnnamedTagDecl(D))
1033 SemaRef.Context.addDeclaratorForUnnamedTagDecl(Enum, DD);
1034 // See if the old tag was defined along with a typedef.
1035 // If it did, mark the new tag as being associated with that typedef.
1036 if (TypedefNameDecl *TND = SemaRef.Context.getTypedefNameForUnnamedTagDecl(D))
1037 SemaRef.Context.addTypedefNameForUnnamedTagDecl(Enum, TND);
1038 if (SubstQualifier(D, Enum)) return nullptr;
1039 Owner->addDecl(Enum);
1041 EnumDecl *Def = D->getDefinition();
1042 if (Def && Def != D) {
1043 // If this is an out-of-line definition of an enum member template, check
1044 // that the underlying types match in the instantiation of both
1046 if (TypeSourceInfo *TI = Def->getIntegerTypeSourceInfo()) {
1047 SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
1048 QualType DefnUnderlying =
1049 SemaRef.SubstType(TI->getType(), TemplateArgs,
1050 UnderlyingLoc, DeclarationName());
1051 SemaRef.CheckEnumRedeclaration(Def->getLocation(), Def->isScoped(),
1053 /*EnumUnderlyingIsImplicit=*/false, Enum);
1057 // C++11 [temp.inst]p1: The implicit instantiation of a class template
1058 // specialization causes the implicit instantiation of the declarations, but
1059 // not the definitions of scoped member enumerations.
1061 // DR1484 clarifies that enumeration definitions inside of a template
1062 // declaration aren't considered entities that can be separately instantiated
1063 // from the rest of the entity they are declared inside of.
1064 if (isDeclWithinFunction(D) ? D == Def : Def && !Enum->isScoped()) {
1065 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
1066 InstantiateEnumDefinition(Enum, Def);
1072 void TemplateDeclInstantiator::InstantiateEnumDefinition(
1073 EnumDecl *Enum, EnumDecl *Pattern) {
1074 Enum->startDefinition();
1076 // Update the location to refer to the definition.
1077 Enum->setLocation(Pattern->getLocation());
1079 SmallVector<Decl*, 4> Enumerators;
1081 EnumConstantDecl *LastEnumConst = nullptr;
1082 for (auto *EC : Pattern->enumerators()) {
1083 // The specified value for the enumerator.
1084 ExprResult Value((Expr *)nullptr);
1085 if (Expr *UninstValue = EC->getInitExpr()) {
1086 // The enumerator's value expression is a constant expression.
1087 EnterExpressionEvaluationContext Unevaluated(
1088 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
1090 Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
1093 // Drop the initial value and continue.
1094 bool isInvalid = false;
1095 if (Value.isInvalid()) {
1100 EnumConstantDecl *EnumConst
1101 = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
1102 EC->getLocation(), EC->getIdentifier(),
1107 EnumConst->setInvalidDecl();
1108 Enum->setInvalidDecl();
1112 SemaRef.InstantiateAttrs(TemplateArgs, EC, EnumConst);
1114 EnumConst->setAccess(Enum->getAccess());
1115 Enum->addDecl(EnumConst);
1116 Enumerators.push_back(EnumConst);
1117 LastEnumConst = EnumConst;
1119 if (Pattern->getDeclContext()->isFunctionOrMethod() &&
1120 !Enum->isScoped()) {
1121 // If the enumeration is within a function or method, record the enum
1122 // constant as a local.
1123 SemaRef.CurrentInstantiationScope->InstantiatedLocal(EC, EnumConst);
1128 SemaRef.ActOnEnumBody(Enum->getLocation(), Enum->getBraceRange(), Enum,
1133 Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
1134 llvm_unreachable("EnumConstantDecls can only occur within EnumDecls.");
1138 TemplateDeclInstantiator::VisitBuiltinTemplateDecl(BuiltinTemplateDecl *D) {
1139 llvm_unreachable("BuiltinTemplateDecls cannot be instantiated.");
1142 Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1143 bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1145 // Create a local instantiation scope for this class template, which
1146 // will contain the instantiations of the template parameters.
1147 LocalInstantiationScope Scope(SemaRef);
1148 TemplateParameterList *TempParams = D->getTemplateParameters();
1149 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1153 CXXRecordDecl *Pattern = D->getTemplatedDecl();
1155 // Instantiate the qualifier. We have to do this first in case
1156 // we're a friend declaration, because if we are then we need to put
1157 // the new declaration in the appropriate context.
1158 NestedNameSpecifierLoc QualifierLoc = Pattern->getQualifierLoc();
1160 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1166 CXXRecordDecl *PrevDecl = nullptr;
1167 ClassTemplateDecl *PrevClassTemplate = nullptr;
1169 if (!isFriend && getPreviousDeclForInstantiation(Pattern)) {
1170 DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
1171 if (!Found.empty()) {
1172 PrevClassTemplate = dyn_cast<ClassTemplateDecl>(Found.front());
1173 if (PrevClassTemplate)
1174 PrevDecl = PrevClassTemplate->getTemplatedDecl();
1178 // If this isn't a friend, then it's a member template, in which
1179 // case we just want to build the instantiation in the
1180 // specialization. If it is a friend, we want to build it in
1181 // the appropriate context.
1182 DeclContext *DC = Owner;
1186 SS.Adopt(QualifierLoc);
1187 DC = SemaRef.computeDeclContext(SS);
1188 if (!DC) return nullptr;
1190 DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
1191 Pattern->getDeclContext(),
1195 // Look for a previous declaration of the template in the owning
1197 LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
1198 Sema::LookupOrdinaryName,
1199 SemaRef.forRedeclarationInCurContext());
1200 SemaRef.LookupQualifiedName(R, DC);
1202 if (R.isSingleResult()) {
1203 PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
1204 if (PrevClassTemplate)
1205 PrevDecl = PrevClassTemplate->getTemplatedDecl();
1208 if (!PrevClassTemplate && QualifierLoc) {
1209 SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
1210 << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
1211 << QualifierLoc.getSourceRange();
1215 bool AdoptedPreviousTemplateParams = false;
1216 if (PrevClassTemplate) {
1217 bool Complain = true;
1219 // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
1220 // template for struct std::tr1::__detail::_Map_base, where the
1221 // template parameters of the friend declaration don't match the
1222 // template parameters of the original declaration. In this one
1223 // case, we don't complain about the ill-formed friend
1225 if (isFriend && Pattern->getIdentifier() &&
1226 Pattern->getIdentifier()->isStr("_Map_base") &&
1227 DC->isNamespace() &&
1228 cast<NamespaceDecl>(DC)->getIdentifier() &&
1229 cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
1230 DeclContext *DCParent = DC->getParent();
1231 if (DCParent->isNamespace() &&
1232 cast<NamespaceDecl>(DCParent)->getIdentifier() &&
1233 cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
1234 if (cast<Decl>(DCParent)->isInStdNamespace())
1239 TemplateParameterList *PrevParams
1240 = PrevClassTemplate->getTemplateParameters();
1242 // Make sure the parameter lists match.
1243 if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
1245 Sema::TPL_TemplateMatch)) {
1249 AdoptedPreviousTemplateParams = true;
1250 InstParams = PrevParams;
1253 // Do some additional validation, then merge default arguments
1254 // from the existing declarations.
1255 if (!AdoptedPreviousTemplateParams &&
1256 SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
1257 Sema::TPC_ClassTemplate))
1262 CXXRecordDecl *RecordInst
1263 = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC,
1264 Pattern->getLocStart(), Pattern->getLocation(),
1265 Pattern->getIdentifier(), PrevDecl,
1266 /*DelayTypeCreation=*/true);
1269 RecordInst->setQualifierInfo(QualifierLoc);
1271 ClassTemplateDecl *Inst
1272 = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
1273 D->getIdentifier(), InstParams, RecordInst);
1274 assert(!(isFriend && Owner->isDependentContext()));
1275 Inst->setPreviousDecl(PrevClassTemplate);
1277 RecordInst->setDescribedClassTemplate(Inst);
1280 if (PrevClassTemplate)
1281 Inst->setAccess(PrevClassTemplate->getAccess());
1283 Inst->setAccess(D->getAccess());
1285 Inst->setObjectOfFriendDecl();
1286 // TODO: do we want to track the instantiation progeny of this
1287 // friend target decl?
1289 Inst->setAccess(D->getAccess());
1290 if (!PrevClassTemplate)
1291 Inst->setInstantiatedFromMemberTemplate(D);
1294 // Trigger creation of the type for the instantiation.
1295 SemaRef.Context.getInjectedClassNameType(RecordInst,
1296 Inst->getInjectedClassNameSpecialization());
1298 // Finish handling of friends.
1300 DC->makeDeclVisibleInContext(Inst);
1301 Inst->setLexicalDeclContext(Owner);
1302 RecordInst->setLexicalDeclContext(Owner);
1306 if (D->isOutOfLine()) {
1307 Inst->setLexicalDeclContext(D->getLexicalDeclContext());
1308 RecordInst->setLexicalDeclContext(D->getLexicalDeclContext());
1311 Owner->addDecl(Inst);
1313 if (!PrevClassTemplate) {
1314 // Queue up any out-of-line partial specializations of this member
1315 // class template; the client will force their instantiation once
1316 // the enclosing class has been instantiated.
1317 SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
1318 D->getPartialSpecializations(PartialSpecs);
1319 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
1320 if (PartialSpecs[I]->getFirstDecl()->isOutOfLine())
1321 OutOfLinePartialSpecs.push_back(std::make_pair(Inst, PartialSpecs[I]));
1328 TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
1329 ClassTemplatePartialSpecializationDecl *D) {
1330 ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
1332 // Lookup the already-instantiated declaration in the instantiation
1333 // of the class template and return that.
1334 DeclContext::lookup_result Found
1335 = Owner->lookup(ClassTemplate->getDeclName());
1339 ClassTemplateDecl *InstClassTemplate
1340 = dyn_cast<ClassTemplateDecl>(Found.front());
1341 if (!InstClassTemplate)
1344 if (ClassTemplatePartialSpecializationDecl *Result
1345 = InstClassTemplate->findPartialSpecInstantiatedFromMember(D))
1348 return InstantiateClassTemplatePartialSpecialization(InstClassTemplate, D);
1351 Decl *TemplateDeclInstantiator::VisitVarTemplateDecl(VarTemplateDecl *D) {
1352 assert(D->getTemplatedDecl()->isStaticDataMember() &&
1353 "Only static data member templates are allowed.");
1355 // Create a local instantiation scope for this variable template, which
1356 // will contain the instantiations of the template parameters.
1357 LocalInstantiationScope Scope(SemaRef);
1358 TemplateParameterList *TempParams = D->getTemplateParameters();
1359 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1363 VarDecl *Pattern = D->getTemplatedDecl();
1364 VarTemplateDecl *PrevVarTemplate = nullptr;
1366 if (getPreviousDeclForInstantiation(Pattern)) {
1367 DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
1369 PrevVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
1373 cast_or_null<VarDecl>(VisitVarDecl(Pattern,
1374 /*InstantiatingVarTemplate=*/true));
1375 if (!VarInst) return nullptr;
1377 DeclContext *DC = Owner;
1379 VarTemplateDecl *Inst = VarTemplateDecl::Create(
1380 SemaRef.Context, DC, D->getLocation(), D->getIdentifier(), InstParams,
1382 VarInst->setDescribedVarTemplate(Inst);
1383 Inst->setPreviousDecl(PrevVarTemplate);
1385 Inst->setAccess(D->getAccess());
1386 if (!PrevVarTemplate)
1387 Inst->setInstantiatedFromMemberTemplate(D);
1389 if (D->isOutOfLine()) {
1390 Inst->setLexicalDeclContext(D->getLexicalDeclContext());
1391 VarInst->setLexicalDeclContext(D->getLexicalDeclContext());
1394 Owner->addDecl(Inst);
1396 if (!PrevVarTemplate) {
1397 // Queue up any out-of-line partial specializations of this member
1398 // variable template; the client will force their instantiation once
1399 // the enclosing class has been instantiated.
1400 SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
1401 D->getPartialSpecializations(PartialSpecs);
1402 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
1403 if (PartialSpecs[I]->getFirstDecl()->isOutOfLine())
1404 OutOfLineVarPartialSpecs.push_back(
1405 std::make_pair(Inst, PartialSpecs[I]));
1411 Decl *TemplateDeclInstantiator::VisitVarTemplatePartialSpecializationDecl(
1412 VarTemplatePartialSpecializationDecl *D) {
1413 assert(D->isStaticDataMember() &&
1414 "Only static data member templates are allowed.");
1416 VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
1418 // Lookup the already-instantiated declaration and return that.
1419 DeclContext::lookup_result Found = Owner->lookup(VarTemplate->getDeclName());
1420 assert(!Found.empty() && "Instantiation found nothing?");
1422 VarTemplateDecl *InstVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
1423 assert(InstVarTemplate && "Instantiation did not find a variable template?");
1425 if (VarTemplatePartialSpecializationDecl *Result =
1426 InstVarTemplate->findPartialSpecInstantiatedFromMember(D))
1429 return InstantiateVarTemplatePartialSpecialization(InstVarTemplate, D);
1433 TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1434 // Create a local instantiation scope for this function template, which
1435 // will contain the instantiations of the template parameters and then get
1436 // merged with the local instantiation scope for the function template
1438 LocalInstantiationScope Scope(SemaRef);
1440 TemplateParameterList *TempParams = D->getTemplateParameters();
1441 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1445 FunctionDecl *Instantiated = nullptr;
1446 if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
1447 Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
1450 Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
1451 D->getTemplatedDecl(),
1457 // Link the instantiated function template declaration to the function
1458 // template from which it was instantiated.
1459 FunctionTemplateDecl *InstTemplate
1460 = Instantiated->getDescribedFunctionTemplate();
1461 InstTemplate->setAccess(D->getAccess());
1462 assert(InstTemplate &&
1463 "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
1465 bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
1467 // Link the instantiation back to the pattern *unless* this is a
1468 // non-definition friend declaration.
1469 if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
1470 !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
1471 InstTemplate->setInstantiatedFromMemberTemplate(D);
1473 // Make declarations visible in the appropriate context.
1475 Owner->addDecl(InstTemplate);
1476 } else if (InstTemplate->getDeclContext()->isRecord() &&
1477 !getPreviousDeclForInstantiation(D)) {
1478 SemaRef.CheckFriendAccess(InstTemplate);
1481 return InstTemplate;
1484 Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
1485 CXXRecordDecl *PrevDecl = nullptr;
1486 if (D->isInjectedClassName())
1487 PrevDecl = cast<CXXRecordDecl>(Owner);
1488 else if (CXXRecordDecl *PatternPrev = getPreviousDeclForInstantiation(D)) {
1489 NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
1492 if (!Prev) return nullptr;
1493 PrevDecl = cast<CXXRecordDecl>(Prev);
1496 CXXRecordDecl *Record
1497 = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner,
1498 D->getLocStart(), D->getLocation(),
1499 D->getIdentifier(), PrevDecl);
1501 // Substitute the nested name specifier, if any.
1502 if (SubstQualifier(D, Record))
1505 Record->setImplicit(D->isImplicit());
1506 // FIXME: Check against AS_none is an ugly hack to work around the issue that
1507 // the tag decls introduced by friend class declarations don't have an access
1508 // specifier. Remove once this area of the code gets sorted out.
1509 if (D->getAccess() != AS_none)
1510 Record->setAccess(D->getAccess());
1511 if (!D->isInjectedClassName())
1512 Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
1514 // If the original function was part of a friend declaration,
1515 // inherit its namespace state.
1516 if (D->getFriendObjectKind())
1517 Record->setObjectOfFriendDecl();
1519 // Make sure that anonymous structs and unions are recorded.
1520 if (D->isAnonymousStructOrUnion())
1521 Record->setAnonymousStructOrUnion(true);
1523 if (D->isLocalClass())
1524 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
1526 // Forward the mangling number from the template to the instantiated decl.
1527 SemaRef.Context.setManglingNumber(Record,
1528 SemaRef.Context.getManglingNumber(D));
1530 // See if the old tag was defined along with a declarator.
1531 // If it did, mark the new tag as being associated with that declarator.
1532 if (DeclaratorDecl *DD = SemaRef.Context.getDeclaratorForUnnamedTagDecl(D))
1533 SemaRef.Context.addDeclaratorForUnnamedTagDecl(Record, DD);
1535 // See if the old tag was defined along with a typedef.
1536 // If it did, mark the new tag as being associated with that typedef.
1537 if (TypedefNameDecl *TND = SemaRef.Context.getTypedefNameForUnnamedTagDecl(D))
1538 SemaRef.Context.addTypedefNameForUnnamedTagDecl(Record, TND);
1540 Owner->addDecl(Record);
1542 // DR1484 clarifies that the members of a local class are instantiated as part
1543 // of the instantiation of their enclosing entity.
1544 if (D->isCompleteDefinition() && D->isLocalClass()) {
1545 Sema::LocalEagerInstantiationScope LocalInstantiations(SemaRef);
1547 SemaRef.InstantiateClass(D->getLocation(), Record, D, TemplateArgs,
1548 TSK_ImplicitInstantiation,
1551 // For nested local classes, we will instantiate the members when we
1552 // reach the end of the outermost (non-nested) local class.
1553 if (!D->isCXXClassMember())
1554 SemaRef.InstantiateClassMembers(D->getLocation(), Record, TemplateArgs,
1555 TSK_ImplicitInstantiation);
1557 // This class may have local implicit instantiations that need to be
1558 // performed within this scope.
1559 LocalInstantiations.perform();
1562 SemaRef.DiagnoseUnusedNestedTypedefs(Record);
1567 /// \brief Adjust the given function type for an instantiation of the
1568 /// given declaration, to cope with modifications to the function's type that
1569 /// aren't reflected in the type-source information.
1571 /// \param D The declaration we're instantiating.
1572 /// \param TInfo The already-instantiated type.
1573 static QualType adjustFunctionTypeForInstantiation(ASTContext &Context,
1575 TypeSourceInfo *TInfo) {
1576 const FunctionProtoType *OrigFunc
1577 = D->getType()->castAs<FunctionProtoType>();
1578 const FunctionProtoType *NewFunc
1579 = TInfo->getType()->castAs<FunctionProtoType>();
1580 if (OrigFunc->getExtInfo() == NewFunc->getExtInfo())
1581 return TInfo->getType();
1583 FunctionProtoType::ExtProtoInfo NewEPI = NewFunc->getExtProtoInfo();
1584 NewEPI.ExtInfo = OrigFunc->getExtInfo();
1585 return Context.getFunctionType(NewFunc->getReturnType(),
1586 NewFunc->getParamTypes(), NewEPI);
1589 /// Normal class members are of more specific types and therefore
1590 /// don't make it here. This function serves two purposes:
1591 /// 1) instantiating function templates
1592 /// 2) substituting friend declarations
1593 Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
1594 TemplateParameterList *TemplateParams) {
1595 // Check whether there is already a function template specialization for
1596 // this declaration.
1597 FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1598 if (FunctionTemplate && !TemplateParams) {
1599 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1601 void *InsertPos = nullptr;
1602 FunctionDecl *SpecFunc
1603 = FunctionTemplate->findSpecialization(Innermost, InsertPos);
1605 // If we already have a function template specialization, return it.
1611 if (FunctionTemplate)
1612 isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1614 isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1616 bool MergeWithParentScope = (TemplateParams != nullptr) ||
1617 Owner->isFunctionOrMethod() ||
1618 !(isa<Decl>(Owner) &&
1619 cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1620 LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1622 SmallVector<ParmVarDecl *, 4> Params;
1623 TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
1626 QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
1628 NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1630 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1636 // If we're instantiating a local function declaration, put the result
1637 // in the enclosing namespace; otherwise we need to find the instantiated
1640 if (D->isLocalExternDecl()) {
1642 SemaRef.adjustContextForLocalExternDecl(DC);
1643 } else if (isFriend && QualifierLoc) {
1645 SS.Adopt(QualifierLoc);
1646 DC = SemaRef.computeDeclContext(SS);
1647 if (!DC) return nullptr;
1649 DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1653 FunctionDecl *Function;
1654 if (auto *DGuide = dyn_cast<CXXDeductionGuideDecl>(D)) {
1655 Function = CXXDeductionGuideDecl::Create(
1656 SemaRef.Context, DC, D->getInnerLocStart(), DGuide->isExplicit(),
1657 D->getNameInfo(), T, TInfo, D->getSourceRange().getEnd());
1658 if (DGuide->isCopyDeductionCandidate())
1659 cast<CXXDeductionGuideDecl>(Function)->setIsCopyDeductionCandidate();
1661 Function = FunctionDecl::Create(
1662 SemaRef.Context, DC, D->getInnerLocStart(), D->getNameInfo(), T, TInfo,
1663 D->getCanonicalDecl()->getStorageClass(), D->isInlineSpecified(),
1664 D->hasWrittenPrototype(), D->isConstexpr());
1665 Function->setRangeEnd(D->getSourceRange().getEnd());
1669 Function->setImplicitlyInline();
1672 Function->setQualifierInfo(QualifierLoc);
1674 if (D->isLocalExternDecl())
1675 Function->setLocalExternDecl();
1677 DeclContext *LexicalDC = Owner;
1678 if (!isFriend && D->isOutOfLine() && !D->isLocalExternDecl()) {
1679 assert(D->getDeclContext()->isFileContext());
1680 LexicalDC = D->getDeclContext();
1683 Function->setLexicalDeclContext(LexicalDC);
1685 // Attach the parameters
1686 for (unsigned P = 0; P < Params.size(); ++P)
1688 Params[P]->setOwningFunction(Function);
1689 Function->setParams(Params);
1691 if (TemplateParams) {
1692 // Our resulting instantiation is actually a function template, since we
1693 // are substituting only the outer template parameters. For example, given
1695 // template<typename T>
1697 // template<typename U> friend void f(T, U);
1702 // We are instantiating the friend function template "f" within X<int>,
1703 // which means substituting int for T, but leaving "f" as a friend function
1705 // Build the function template itself.
1706 FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1707 Function->getLocation(),
1708 Function->getDeclName(),
1709 TemplateParams, Function);
1710 Function->setDescribedFunctionTemplate(FunctionTemplate);
1712 FunctionTemplate->setLexicalDeclContext(LexicalDC);
1714 if (isFriend && D->isThisDeclarationADefinition()) {
1715 FunctionTemplate->setInstantiatedFromMemberTemplate(
1716 D->getDescribedFunctionTemplate());
1718 } else if (FunctionTemplate) {
1719 // Record this function template specialization.
1720 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1721 Function->setFunctionTemplateSpecialization(FunctionTemplate,
1722 TemplateArgumentList::CreateCopy(SemaRef.Context,
1724 /*InsertPos=*/nullptr);
1725 } else if (isFriend && D->isThisDeclarationADefinition()) {
1726 // Do not connect the friend to the template unless it's actually a
1727 // definition. We don't want non-template functions to be marked as being
1728 // template instantiations.
1729 Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1732 if (InitFunctionInstantiation(Function, D))
1733 Function->setInvalidDecl();
1735 bool isExplicitSpecialization = false;
1737 LookupResult Previous(
1738 SemaRef, Function->getDeclName(), SourceLocation(),
1739 D->isLocalExternDecl() ? Sema::LookupRedeclarationWithLinkage
1740 : Sema::LookupOrdinaryName,
1741 D->isLocalExternDecl() ? Sema::ForExternalRedeclaration
1742 : SemaRef.forRedeclarationInCurContext());
1744 if (DependentFunctionTemplateSpecializationInfo *Info
1745 = D->getDependentSpecializationInfo()) {
1746 assert(isFriend && "non-friend has dependent specialization info?");
1748 // This needs to be set now for future sanity.
1749 Function->setObjectOfFriendDecl();
1751 // Instantiate the explicit template arguments.
1752 TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1753 Info->getRAngleLoc());
1754 if (SemaRef.Subst(Info->getTemplateArgs(), Info->getNumTemplateArgs(),
1755 ExplicitArgs, TemplateArgs))
1758 // Map the candidate templates to their instantiations.
1759 for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1760 Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1761 Info->getTemplate(I),
1763 if (!Temp) return nullptr;
1765 Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1768 if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1771 Function->setInvalidDecl();
1773 isExplicitSpecialization = true;
1775 } else if (TemplateParams || !FunctionTemplate) {
1776 // Look only into the namespace where the friend would be declared to
1777 // find a previous declaration. This is the innermost enclosing namespace,
1778 // as described in ActOnFriendFunctionDecl.
1779 SemaRef.LookupQualifiedName(Previous, DC);
1781 // In C++, the previous declaration we find might be a tag type
1782 // (class or enum). In this case, the new declaration will hide the
1783 // tag type. Note that this does does not apply if we're declaring a
1784 // typedef (C++ [dcl.typedef]p4).
1785 if (Previous.isSingleTagDecl())
1790 Function->setObjectOfFriendDecl();
1792 SemaRef.CheckFunctionDeclaration(/*Scope*/ nullptr, Function, Previous,
1793 isExplicitSpecialization);
1795 NamedDecl *PrincipalDecl = (TemplateParams
1796 ? cast<NamedDecl>(FunctionTemplate)
1799 // If the original function was part of a friend declaration,
1800 // inherit its namespace state and add it to the owner.
1802 PrincipalDecl->setObjectOfFriendDecl();
1803 DC->makeDeclVisibleInContext(PrincipalDecl);
1805 bool QueuedInstantiation = false;
1807 // C++11 [temp.friend]p4 (DR329):
1808 // When a function is defined in a friend function declaration in a class
1809 // template, the function is instantiated when the function is odr-used.
1810 // The same restrictions on multiple declarations and definitions that
1811 // apply to non-template function declarations and definitions also apply
1812 // to these implicit definitions.
1813 if (D->isThisDeclarationADefinition()) {
1814 // Check for a function body.
1815 const FunctionDecl *Definition = nullptr;
1816 if (Function->isDefined(Definition) &&
1817 Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
1818 SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1819 << Function->getDeclName();
1820 SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
1822 // Check for redefinitions due to other instantiations of this or
1823 // a similar friend function.
1824 else for (auto R : Function->redecls()) {
1828 // If some prior declaration of this function has been used, we need
1829 // to instantiate its definition.
1830 if (!QueuedInstantiation && R->isUsed(false)) {
1831 if (MemberSpecializationInfo *MSInfo =
1832 Function->getMemberSpecializationInfo()) {
1833 if (MSInfo->getPointOfInstantiation().isInvalid()) {
1834 SourceLocation Loc = R->getLocation(); // FIXME
1835 MSInfo->setPointOfInstantiation(Loc);
1836 SemaRef.PendingLocalImplicitInstantiations.push_back(
1837 std::make_pair(Function, Loc));
1838 QueuedInstantiation = true;
1843 // If some prior declaration of this function was a friend with an
1844 // uninstantiated definition, reject it.
1845 if (R->getFriendObjectKind()) {
1846 if (const FunctionDecl *RPattern =
1847 R->getTemplateInstantiationPattern()) {
1848 if (RPattern->isDefined(RPattern)) {
1849 SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
1850 << Function->getDeclName();
1851 SemaRef.Diag(R->getLocation(), diag::note_previous_definition);
1859 // Check the template parameter list against the previous declaration. The
1860 // goal here is to pick up default arguments added since the friend was
1861 // declared; we know the template parameter lists match, since otherwise
1862 // we would not have picked this template as the previous declaration.
1863 if (TemplateParams && FunctionTemplate->getPreviousDecl()) {
1864 SemaRef.CheckTemplateParameterList(
1866 FunctionTemplate->getPreviousDecl()->getTemplateParameters(),
1867 Function->isThisDeclarationADefinition()
1868 ? Sema::TPC_FriendFunctionTemplateDefinition
1869 : Sema::TPC_FriendFunctionTemplate);
1873 if (Function->isLocalExternDecl() && !Function->getPreviousDecl())
1874 DC->makeDeclVisibleInContext(PrincipalDecl);
1876 if (Function->isOverloadedOperator() && !DC->isRecord() &&
1877 PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
1878 PrincipalDecl->setNonMemberOperator();
1880 assert(!D->isDefaulted() && "only methods should be defaulted");
1885 TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D,
1886 TemplateParameterList *TemplateParams,
1887 bool IsClassScopeSpecialization) {
1888 FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1889 if (FunctionTemplate && !TemplateParams) {
1890 // We are creating a function template specialization from a function
1891 // template. Check whether there is already a function template
1892 // specialization for this particular set of template arguments.
1893 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1895 void *InsertPos = nullptr;
1896 FunctionDecl *SpecFunc
1897 = FunctionTemplate->findSpecialization(Innermost, InsertPos);
1899 // If we already have a function template specialization, return it.
1905 if (FunctionTemplate)
1906 isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1908 isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1910 bool MergeWithParentScope = (TemplateParams != nullptr) ||
1911 !(isa<Decl>(Owner) &&
1912 cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1913 LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1915 // Instantiate enclosing template arguments for friends.
1916 SmallVector<TemplateParameterList *, 4> TempParamLists;
1917 unsigned NumTempParamLists = 0;
1918 if (isFriend && (NumTempParamLists = D->getNumTemplateParameterLists())) {
1919 TempParamLists.resize(NumTempParamLists);
1920 for (unsigned I = 0; I != NumTempParamLists; ++I) {
1921 TemplateParameterList *TempParams = D->getTemplateParameterList(I);
1922 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1925 TempParamLists[I] = InstParams;
1929 SmallVector<ParmVarDecl *, 4> Params;
1930 TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
1933 QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
1935 NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1937 QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1943 DeclContext *DC = Owner;
1947 SS.Adopt(QualifierLoc);
1948 DC = SemaRef.computeDeclContext(SS);
1950 if (DC && SemaRef.RequireCompleteDeclContext(SS, DC))
1953 DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1954 D->getDeclContext(),
1957 if (!DC) return nullptr;
1960 // Build the instantiated method declaration.
1961 CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1962 CXXMethodDecl *Method = nullptr;
1964 SourceLocation StartLoc = D->getInnerLocStart();
1965 DeclarationNameInfo NameInfo
1966 = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1967 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1968 Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1969 StartLoc, NameInfo, T, TInfo,
1970 Constructor->isExplicit(),
1971 Constructor->isInlineSpecified(),
1972 false, Constructor->isConstexpr());
1973 Method->setRangeEnd(Constructor->getLocEnd());
1974 } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1975 Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1976 StartLoc, NameInfo, T, TInfo,
1977 Destructor->isInlineSpecified(),
1979 Method->setRangeEnd(Destructor->getLocEnd());
1980 } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1981 Method = CXXConversionDecl::Create(SemaRef.Context, Record,
1982 StartLoc, NameInfo, T, TInfo,
1983 Conversion->isInlineSpecified(),
1984 Conversion->isExplicit(),
1985 Conversion->isConstexpr(),
1986 Conversion->getLocEnd());
1988 StorageClass SC = D->isStatic() ? SC_Static : SC_None;
1989 Method = CXXMethodDecl::Create(SemaRef.Context, Record,
1990 StartLoc, NameInfo, T, TInfo,
1991 SC, D->isInlineSpecified(),
1992 D->isConstexpr(), D->getLocEnd());
1996 Method->setImplicitlyInline();
1999 Method->setQualifierInfo(QualifierLoc);
2001 if (TemplateParams) {
2002 // Our resulting instantiation is actually a function template, since we
2003 // are substituting only the outer template parameters. For example, given
2005 // template<typename T>
2007 // template<typename U> void f(T, U);
2012 // We are instantiating the member template "f" within X<int>, which means
2013 // substituting int for T, but leaving "f" as a member function template.
2014 // Build the function template itself.
2015 FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
2016 Method->getLocation(),
2017 Method->getDeclName(),
2018 TemplateParams, Method);
2020 FunctionTemplate->setLexicalDeclContext(Owner);
2021 FunctionTemplate->setObjectOfFriendDecl();
2022 } else if (D->isOutOfLine())
2023 FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
2024 Method->setDescribedFunctionTemplate(FunctionTemplate);
2025 } else if (FunctionTemplate) {
2026 // Record this function template specialization.
2027 ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
2028 Method->setFunctionTemplateSpecialization(FunctionTemplate,
2029 TemplateArgumentList::CreateCopy(SemaRef.Context,
2031 /*InsertPos=*/nullptr);
2032 } else if (!isFriend) {
2033 // Record that this is an instantiation of a member function.
2034 Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
2037 // If we are instantiating a member function defined
2038 // out-of-line, the instantiation will have the same lexical
2039 // context (which will be a namespace scope) as the template.
2041 if (NumTempParamLists)
2042 Method->setTemplateParameterListsInfo(
2044 llvm::makeArrayRef(TempParamLists.data(), NumTempParamLists));
2046 Method->setLexicalDeclContext(Owner);
2047 Method->setObjectOfFriendDecl();
2048 } else if (D->isOutOfLine())
2049 Method->setLexicalDeclContext(D->getLexicalDeclContext());
2051 // Attach the parameters
2052 for (unsigned P = 0; P < Params.size(); ++P)
2053 Params[P]->setOwningFunction(Method);
2054 Method->setParams(Params);
2056 if (InitMethodInstantiation(Method, D))
2057 Method->setInvalidDecl();
2059 LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
2060 Sema::ForExternalRedeclaration);
2062 if (!FunctionTemplate || TemplateParams || isFriend) {
2063 SemaRef.LookupQualifiedName(Previous, Record);
2065 // In C++, the previous declaration we find might be a tag type
2066 // (class or enum). In this case, the new declaration will hide the
2067 // tag type. Note that this does does not apply if we're declaring a
2068 // typedef (C++ [dcl.typedef]p4).
2069 if (Previous.isSingleTagDecl())
2073 if (!IsClassScopeSpecialization)
2074 SemaRef.CheckFunctionDeclaration(nullptr, Method, Previous, false);
2077 SemaRef.CheckPureMethod(Method, SourceRange());
2079 // Propagate access. For a non-friend declaration, the access is
2080 // whatever we're propagating from. For a friend, it should be the
2081 // previous declaration we just found.
2082 if (isFriend && Method->getPreviousDecl())
2083 Method->setAccess(Method->getPreviousDecl()->getAccess());
2085 Method->setAccess(D->getAccess());
2086 if (FunctionTemplate)
2087 FunctionTemplate->setAccess(Method->getAccess());
2089 SemaRef.CheckOverrideControl(Method);
2091 // If a function is defined as defaulted or deleted, mark it as such now.
2092 if (D->isExplicitlyDefaulted())
2093 SemaRef.SetDeclDefaulted(Method, Method->getLocation());
2094 if (D->isDeletedAsWritten())
2095 SemaRef.SetDeclDeleted(Method, Method->getLocation());
2097 // If there's a function template, let our caller handle it.
2098 if (FunctionTemplate) {
2101 // Don't hide a (potentially) valid declaration with an invalid one.
2102 } else if (Method->isInvalidDecl() && !Previous.empty()) {
2105 // Otherwise, check access to friends and make them visible.
2106 } else if (isFriend) {
2107 // We only need to re-check access for methods which we didn't
2108 // manage to match during parsing.
2109 if (!D->getPreviousDecl())
2110 SemaRef.CheckFriendAccess(Method);
2112 Record->makeDeclVisibleInContext(Method);
2114 // Otherwise, add the declaration. We don't need to do this for
2115 // class-scope specializations because we'll have matched them with
2116 // the appropriate template.
2117 } else if (!IsClassScopeSpecialization) {
2118 Owner->addDecl(Method);
2124 Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
2125 return VisitCXXMethodDecl(D);
2128 Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
2129 return VisitCXXMethodDecl(D);
2132 Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
2133 return VisitCXXMethodDecl(D);
2136 Decl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
2137 return SemaRef.SubstParmVarDecl(D, TemplateArgs, /*indexAdjustment*/ 0, None,
2138 /*ExpectParameterPack=*/ false);
2141 Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
2142 TemplateTypeParmDecl *D) {
2143 // TODO: don't always clone when decls are refcounted.
2144 assert(D->getTypeForDecl()->isTemplateTypeParmType());
2146 TemplateTypeParmDecl *Inst = TemplateTypeParmDecl::Create(
2147 SemaRef.Context, Owner, D->getLocStart(), D->getLocation(),
2148 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(), D->getIndex(),
2149 D->getIdentifier(), D->wasDeclaredWithTypename(), D->isParameterPack());
2150 Inst->setAccess(AS_public);
2152 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2153 TypeSourceInfo *InstantiatedDefaultArg =
2154 SemaRef.SubstType(D->getDefaultArgumentInfo(), TemplateArgs,
2155 D->getDefaultArgumentLoc(), D->getDeclName());
2156 if (InstantiatedDefaultArg)
2157 Inst->setDefaultArgument(InstantiatedDefaultArg);
2160 // Introduce this template parameter's instantiation into the instantiation
2162 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
2167 Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
2168 NonTypeTemplateParmDecl *D) {
2169 // Substitute into the type of the non-type template parameter.
2170 TypeLoc TL = D->getTypeSourceInfo()->getTypeLoc();
2171 SmallVector<TypeSourceInfo *, 4> ExpandedParameterPackTypesAsWritten;
2172 SmallVector<QualType, 4> ExpandedParameterPackTypes;
2173 bool IsExpandedParameterPack = false;
2176 bool Invalid = false;
2178 if (D->isExpandedParameterPack()) {
2179 // The non-type template parameter pack is an already-expanded pack
2180 // expansion of types. Substitute into each of the expanded types.
2181 ExpandedParameterPackTypes.reserve(D->getNumExpansionTypes());
2182 ExpandedParameterPackTypesAsWritten.reserve(D->getNumExpansionTypes());
2183 for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
2184 TypeSourceInfo *NewDI =
2185 SemaRef.SubstType(D->getExpansionTypeSourceInfo(I), TemplateArgs,
2186 D->getLocation(), D->getDeclName());
2191 SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
2195 ExpandedParameterPackTypesAsWritten.push_back(NewDI);
2196 ExpandedParameterPackTypes.push_back(NewT);
2199 IsExpandedParameterPack = true;
2200 DI = D->getTypeSourceInfo();
2202 } else if (D->isPackExpansion()) {
2203 // The non-type template parameter pack's type is a pack expansion of types.
2204 // Determine whether we need to expand this parameter pack into separate
2206 PackExpansionTypeLoc Expansion = TL.castAs<PackExpansionTypeLoc>();
2207 TypeLoc Pattern = Expansion.getPatternLoc();
2208 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2209 SemaRef.collectUnexpandedParameterPacks(Pattern, Unexpanded);
2211 // Determine whether the set of unexpanded parameter packs can and should
2214 bool RetainExpansion = false;
2215 Optional<unsigned> OrigNumExpansions
2216 = Expansion.getTypePtr()->getNumExpansions();
2217 Optional<unsigned> NumExpansions = OrigNumExpansions;
2218 if (SemaRef.CheckParameterPacksForExpansion(Expansion.getEllipsisLoc(),
2219 Pattern.getSourceRange(),
2222 Expand, RetainExpansion,
2227 for (unsigned I = 0; I != *NumExpansions; ++I) {
2228 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2229 TypeSourceInfo *NewDI = SemaRef.SubstType(Pattern, TemplateArgs,
2236 SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
2240 ExpandedParameterPackTypesAsWritten.push_back(NewDI);
2241 ExpandedParameterPackTypes.push_back(NewT);
2244 // Note that we have an expanded parameter pack. The "type" of this
2245 // expanded parameter pack is the original expansion type, but callers
2246 // will end up using the expanded parameter pack types for type-checking.
2247 IsExpandedParameterPack = true;
2248 DI = D->getTypeSourceInfo();
2251 // We cannot fully expand the pack expansion now, so substitute into the
2252 // pattern and create a new pack expansion type.
2253 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2254 TypeSourceInfo *NewPattern = SemaRef.SubstType(Pattern, TemplateArgs,
2260 SemaRef.CheckNonTypeTemplateParameterType(NewPattern, D->getLocation());
2261 DI = SemaRef.CheckPackExpansion(NewPattern, Expansion.getEllipsisLoc(),
2269 // Simple case: substitution into a parameter that is not a parameter pack.
2270 DI = SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
2271 D->getLocation(), D->getDeclName());
2275 // Check that this type is acceptable for a non-type template parameter.
2276 T = SemaRef.CheckNonTypeTemplateParameterType(DI, D->getLocation());
2278 T = SemaRef.Context.IntTy;
2283 NonTypeTemplateParmDecl *Param;
2284 if (IsExpandedParameterPack)
2285 Param = NonTypeTemplateParmDecl::Create(
2286 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
2287 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2288 D->getPosition(), D->getIdentifier(), T, DI, ExpandedParameterPackTypes,
2289 ExpandedParameterPackTypesAsWritten);
2291 Param = NonTypeTemplateParmDecl::Create(
2292 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
2293 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2294 D->getPosition(), D->getIdentifier(), T, D->isParameterPack(), DI);
2296 Param->setAccess(AS_public);
2298 Param->setInvalidDecl();
2300 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2301 EnterExpressionEvaluationContext ConstantEvaluated(
2302 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
2303 ExprResult Value = SemaRef.SubstExpr(D->getDefaultArgument(), TemplateArgs);
2304 if (!Value.isInvalid())
2305 Param->setDefaultArgument(Value.get());
2308 // Introduce this template parameter's instantiation into the instantiation
2310 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
2314 static void collectUnexpandedParameterPacks(
2316 TemplateParameterList *Params,
2317 SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) {
2318 for (const auto &P : *Params) {
2319 if (P->isTemplateParameterPack())
2321 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P))
2322 S.collectUnexpandedParameterPacks(NTTP->getTypeSourceInfo()->getTypeLoc(),
2324 if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(P))
2325 collectUnexpandedParameterPacks(S, TTP->getTemplateParameters(),
2331 TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
2332 TemplateTemplateParmDecl *D) {
2333 // Instantiate the template parameter list of the template template parameter.
2334 TemplateParameterList *TempParams = D->getTemplateParameters();
2335 TemplateParameterList *InstParams;
2336 SmallVector<TemplateParameterList*, 8> ExpandedParams;
2338 bool IsExpandedParameterPack = false;
2340 if (D->isExpandedParameterPack()) {
2341 // The template template parameter pack is an already-expanded pack
2342 // expansion of template parameters. Substitute into each of the expanded
2344 ExpandedParams.reserve(D->getNumExpansionTemplateParameters());
2345 for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
2347 LocalInstantiationScope Scope(SemaRef);
2348 TemplateParameterList *Expansion =
2349 SubstTemplateParams(D->getExpansionTemplateParameters(I));
2352 ExpandedParams.push_back(Expansion);
2355 IsExpandedParameterPack = true;
2356 InstParams = TempParams;
2357 } else if (D->isPackExpansion()) {
2358 // The template template parameter pack expands to a pack of template
2359 // template parameters. Determine whether we need to expand this parameter
2360 // pack into separate parameters.
2361 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2362 collectUnexpandedParameterPacks(SemaRef, D->getTemplateParameters(),
2365 // Determine whether the set of unexpanded parameter packs can and should
2368 bool RetainExpansion = false;
2369 Optional<unsigned> NumExpansions;
2370 if (SemaRef.CheckParameterPacksForExpansion(D->getLocation(),
2371 TempParams->getSourceRange(),
2374 Expand, RetainExpansion,
2379 for (unsigned I = 0; I != *NumExpansions; ++I) {
2380 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2381 LocalInstantiationScope Scope(SemaRef);
2382 TemplateParameterList *Expansion = SubstTemplateParams(TempParams);
2385 ExpandedParams.push_back(Expansion);
2388 // Note that we have an expanded parameter pack. The "type" of this
2389 // expanded parameter pack is the original expansion type, but callers
2390 // will end up using the expanded parameter pack types for type-checking.
2391 IsExpandedParameterPack = true;
2392 InstParams = TempParams;
2394 // We cannot fully expand the pack expansion now, so just substitute
2395 // into the pattern.
2396 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2398 LocalInstantiationScope Scope(SemaRef);
2399 InstParams = SubstTemplateParams(TempParams);
2404 // Perform the actual substitution of template parameters within a new,
2405 // local instantiation scope.
2406 LocalInstantiationScope Scope(SemaRef);
2407 InstParams = SubstTemplateParams(TempParams);
2412 // Build the template template parameter.
2413 TemplateTemplateParmDecl *Param;
2414 if (IsExpandedParameterPack)
2415 Param = TemplateTemplateParmDecl::Create(
2416 SemaRef.Context, Owner, D->getLocation(),
2417 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2418 D->getPosition(), D->getIdentifier(), InstParams, ExpandedParams);
2420 Param = TemplateTemplateParmDecl::Create(
2421 SemaRef.Context, Owner, D->getLocation(),
2422 D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2423 D->getPosition(), D->isParameterPack(), D->getIdentifier(), InstParams);
2424 if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2425 NestedNameSpecifierLoc QualifierLoc =
2426 D->getDefaultArgument().getTemplateQualifierLoc();
2428 SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgs);
2429 TemplateName TName = SemaRef.SubstTemplateName(
2430 QualifierLoc, D->getDefaultArgument().getArgument().getAsTemplate(),
2431 D->getDefaultArgument().getTemplateNameLoc(), TemplateArgs);
2432 if (!TName.isNull())
2433 Param->setDefaultArgument(
2435 TemplateArgumentLoc(TemplateArgument(TName),
2436 D->getDefaultArgument().getTemplateQualifierLoc(),
2437 D->getDefaultArgument().getTemplateNameLoc()));
2439 Param->setAccess(AS_public);
2441 // Introduce this template parameter's instantiation into the instantiation
2443 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
2448 Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
2449 // Using directives are never dependent (and never contain any types or
2450 // expressions), so they require no explicit instantiation work.
2452 UsingDirectiveDecl *Inst
2453 = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
2454 D->getNamespaceKeyLocation(),
2455 D->getQualifierLoc(),
2456 D->getIdentLocation(),
2457 D->getNominatedNamespace(),
2458 D->getCommonAncestor());
2460 // Add the using directive to its declaration context
2461 // only if this is not a function or method.
2462 if (!Owner->isFunctionOrMethod())
2463 Owner->addDecl(Inst);
2468 Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
2470 // The nested name specifier may be dependent, for example
2471 // template <typename T> struct t {
2472 // struct s1 { T f1(); };
2473 // struct s2 : s1 { using s1::f1; };
2475 // template struct t<int>;
2476 // Here, in using s1::f1, s1 refers to t<T>::s1;
2477 // we need to substitute for t<int>::s1.
2478 NestedNameSpecifierLoc QualifierLoc
2479 = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
2484 // For an inheriting constructor declaration, the name of the using
2485 // declaration is the name of a constructor in this class, not in the
2487 DeclarationNameInfo NameInfo = D->getNameInfo();
2488 if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName)
2489 if (auto *RD = dyn_cast<CXXRecordDecl>(SemaRef.CurContext))
2490 NameInfo.setName(SemaRef.Context.DeclarationNames.getCXXConstructorName(
2491 SemaRef.Context.getCanonicalType(SemaRef.Context.getRecordType(RD))));
2493 // We only need to do redeclaration lookups if we're in a class
2494 // scope (in fact, it's not really even possible in non-class
2496 bool CheckRedeclaration = Owner->isRecord();
2498 LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
2499 Sema::ForVisibleRedeclaration);
2501 UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
2508 SS.Adopt(QualifierLoc);
2509 if (CheckRedeclaration) {
2510 Prev.setHideTags(false);
2511 SemaRef.LookupQualifiedName(Prev, Owner);
2513 // Check for invalid redeclarations.
2514 if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLoc(),
2515 D->hasTypename(), SS,
2516 D->getLocation(), Prev))
2517 NewUD->setInvalidDecl();
2521 if (!NewUD->isInvalidDecl() &&
2522 SemaRef.CheckUsingDeclQualifier(D->getUsingLoc(), D->hasTypename(),
2523 SS, NameInfo, D->getLocation()))
2524 NewUD->setInvalidDecl();
2526 SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
2527 NewUD->setAccess(D->getAccess());
2528 Owner->addDecl(NewUD);
2530 // Don't process the shadow decls for an invalid decl.
2531 if (NewUD->isInvalidDecl())
2534 if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName)
2535 SemaRef.CheckInheritingConstructorUsingDecl(NewUD);
2537 bool isFunctionScope = Owner->isFunctionOrMethod();
2539 // Process the shadow decls.
2540 for (auto *Shadow : D->shadows()) {
2541 // FIXME: UsingShadowDecl doesn't preserve its immediate target, so
2542 // reconstruct it in the case where it matters.
2543 NamedDecl *OldTarget = Shadow->getTargetDecl();
2544 if (auto *CUSD = dyn_cast<ConstructorUsingShadowDecl>(Shadow))
2545 if (auto *BaseShadow = CUSD->getNominatedBaseClassShadowDecl())
2546 OldTarget = BaseShadow;
2548 NamedDecl *InstTarget =
2549 cast_or_null<NamedDecl>(SemaRef.FindInstantiatedDecl(
2550 Shadow->getLocation(), OldTarget, TemplateArgs));
2554 UsingShadowDecl *PrevDecl = nullptr;
2555 if (CheckRedeclaration) {
2556 if (SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev, PrevDecl))
2558 } else if (UsingShadowDecl *OldPrev =
2559 getPreviousDeclForInstantiation(Shadow)) {
2560 PrevDecl = cast_or_null<UsingShadowDecl>(SemaRef.FindInstantiatedDecl(
2561 Shadow->getLocation(), OldPrev, TemplateArgs));
2564 UsingShadowDecl *InstShadow =
2565 SemaRef.BuildUsingShadowDecl(/*Scope*/nullptr, NewUD, InstTarget,
2567 SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
2569 if (isFunctionScope)
2570 SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
2576 Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
2577 // Ignore these; we handle them in bulk when processing the UsingDecl.
2581 Decl *TemplateDeclInstantiator::VisitConstructorUsingShadowDecl(
2582 ConstructorUsingShadowDecl *D) {
2583 // Ignore these; we handle them in bulk when processing the UsingDecl.
2587 template <typename T>
2588 Decl *TemplateDeclInstantiator::instantiateUnresolvedUsingDecl(
2589 T *D, bool InstantiatingPackElement) {
2590 // If this is a pack expansion, expand it now.
2591 if (D->isPackExpansion() && !InstantiatingPackElement) {
2592 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2593 SemaRef.collectUnexpandedParameterPacks(D->getQualifierLoc(), Unexpanded);
2594 SemaRef.collectUnexpandedParameterPacks(D->getNameInfo(), Unexpanded);
2596 // Determine whether the set of unexpanded parameter packs can and should
2599 bool RetainExpansion = false;
2600 Optional<unsigned> NumExpansions;
2601 if (SemaRef.CheckParameterPacksForExpansion(
2602 D->getEllipsisLoc(), D->getSourceRange(), Unexpanded, TemplateArgs,
2603 Expand, RetainExpansion, NumExpansions))
2606 // This declaration cannot appear within a function template signature,
2607 // so we can't have a partial argument list for a parameter pack.
2608 assert(!RetainExpansion &&
2609 "should never need to retain an expansion for UsingPackDecl");
2612 // We cannot fully expand the pack expansion now, so substitute into the
2613 // pattern and create a new pack expansion.
2614 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2615 return instantiateUnresolvedUsingDecl(D, true);
2618 // Within a function, we don't have any normal way to check for conflicts
2619 // between shadow declarations from different using declarations in the
2620 // same pack expansion, but this is always ill-formed because all expansions
2621 // must produce (conflicting) enumerators.
2623 // Sadly we can't just reject this in the template definition because it
2624 // could be valid if the pack is empty or has exactly one expansion.
2625 if (D->getDeclContext()->isFunctionOrMethod() && *NumExpansions > 1) {
2626 SemaRef.Diag(D->getEllipsisLoc(),
2627 diag::err_using_decl_redeclaration_expansion);
2631 // Instantiate the slices of this pack and build a UsingPackDecl.
2632 SmallVector<NamedDecl*, 8> Expansions;
2633 for (unsigned I = 0; I != *NumExpansions; ++I) {
2634 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2635 Decl *Slice = instantiateUnresolvedUsingDecl(D, true);
2638 // Note that we can still get unresolved using declarations here, if we
2639 // had arguments for all packs but the pattern also contained other
2640 // template arguments (this only happens during partial substitution, eg
2641 // into the body of a generic lambda in a function template).
2642 Expansions.push_back(cast<NamedDecl>(Slice));
2645 auto *NewD = SemaRef.BuildUsingPackDecl(D, Expansions);
2646 if (isDeclWithinFunction(D))
2647 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewD);
2651 UnresolvedUsingTypenameDecl *TD = dyn_cast<UnresolvedUsingTypenameDecl>(D);
2652 SourceLocation TypenameLoc = TD ? TD->getTypenameLoc() : SourceLocation();
2654 NestedNameSpecifierLoc QualifierLoc
2655 = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
2661 SS.Adopt(QualifierLoc);
2663 DeclarationNameInfo NameInfo
2664 = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
2666 // Produce a pack expansion only if we're not instantiating a particular
2667 // slice of a pack expansion.
2668 bool InstantiatingSlice = D->getEllipsisLoc().isValid() &&
2669 SemaRef.ArgumentPackSubstitutionIndex != -1;
2670 SourceLocation EllipsisLoc =
2671 InstantiatingSlice ? SourceLocation() : D->getEllipsisLoc();
2673 NamedDecl *UD = SemaRef.BuildUsingDeclaration(
2674 /*Scope*/ nullptr, D->getAccess(), D->getUsingLoc(),
2675 /*HasTypename*/ TD, TypenameLoc, SS, NameInfo, EllipsisLoc, nullptr,
2676 /*IsInstantiation*/ true);
2678 SemaRef.Context.setInstantiatedFromUsingDecl(UD, D);
2683 Decl *TemplateDeclInstantiator::VisitUnresolvedUsingTypenameDecl(
2684 UnresolvedUsingTypenameDecl *D) {
2685 return instantiateUnresolvedUsingDecl(D);
2688 Decl *TemplateDeclInstantiator::VisitUnresolvedUsingValueDecl(
2689 UnresolvedUsingValueDecl *D) {
2690 return instantiateUnresolvedUsingDecl(D);
2693 Decl *TemplateDeclInstantiator::VisitUsingPackDecl(UsingPackDecl *D) {
2694 SmallVector<NamedDecl*, 8> Expansions;
2695 for (auto *UD : D->expansions()) {
2697 SemaRef.FindInstantiatedDecl(D->getLocation(), UD, TemplateArgs))
2698 Expansions.push_back(cast<NamedDecl>(NewUD));
2703 auto *NewD = SemaRef.BuildUsingPackDecl(D, Expansions);
2704 if (isDeclWithinFunction(D))
2705 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewD);
2709 Decl *TemplateDeclInstantiator::VisitClassScopeFunctionSpecializationDecl(
2710 ClassScopeFunctionSpecializationDecl *Decl) {
2711 CXXMethodDecl *OldFD = Decl->getSpecialization();
2712 CXXMethodDecl *NewFD =
2713 cast_or_null<CXXMethodDecl>(VisitCXXMethodDecl(OldFD, nullptr, true));
2717 LookupResult Previous(SemaRef, NewFD->getNameInfo(), Sema::LookupOrdinaryName,
2718 Sema::ForExternalRedeclaration);
2720 TemplateArgumentListInfo TemplateArgs;
2721 TemplateArgumentListInfo *TemplateArgsPtr = nullptr;
2722 if (Decl->hasExplicitTemplateArgs()) {
2723 TemplateArgs = Decl->templateArgs();
2724 TemplateArgsPtr = &TemplateArgs;
2727 SemaRef.LookupQualifiedName(Previous, SemaRef.CurContext);
2728 if (SemaRef.CheckFunctionTemplateSpecialization(NewFD, TemplateArgsPtr,
2730 NewFD->setInvalidDecl();
2734 // Associate the specialization with the pattern.
2735 FunctionDecl *Specialization = cast<FunctionDecl>(Previous.getFoundDecl());
2736 assert(Specialization && "Class scope Specialization is null");
2737 SemaRef.Context.setClassScopeSpecializationPattern(Specialization, OldFD);
2742 Decl *TemplateDeclInstantiator::VisitOMPThreadPrivateDecl(
2743 OMPThreadPrivateDecl *D) {
2744 SmallVector<Expr *, 5> Vars;
2745 for (auto *I : D->varlists()) {
2746 Expr *Var = SemaRef.SubstExpr(I, TemplateArgs).get();
2747 assert(isa<DeclRefExpr>(Var) && "threadprivate arg is not a DeclRefExpr");
2748 Vars.push_back(Var);
2751 OMPThreadPrivateDecl *TD =
2752 SemaRef.CheckOMPThreadPrivateDecl(D->getLocation(), Vars);
2754 TD->setAccess(AS_public);
2760 Decl *TemplateDeclInstantiator::VisitOMPDeclareReductionDecl(
2761 OMPDeclareReductionDecl *D) {
2762 // Instantiate type and check if it is allowed.
2763 QualType SubstReductionType = SemaRef.ActOnOpenMPDeclareReductionType(
2765 ParsedType::make(SemaRef.SubstType(D->getType(), TemplateArgs,
2766 D->getLocation(), DeclarationName())));
2767 if (SubstReductionType.isNull())
2769 bool IsCorrect = !SubstReductionType.isNull();
2770 // Create instantiated copy.
2771 std::pair<QualType, SourceLocation> ReductionTypes[] = {
2772 std::make_pair(SubstReductionType, D->getLocation())};
2773 auto *PrevDeclInScope = D->getPrevDeclInScope();
2774 if (PrevDeclInScope && !PrevDeclInScope->isInvalidDecl()) {
2775 PrevDeclInScope = cast<OMPDeclareReductionDecl>(
2776 SemaRef.CurrentInstantiationScope->findInstantiationOf(PrevDeclInScope)
2779 auto DRD = SemaRef.ActOnOpenMPDeclareReductionDirectiveStart(
2780 /*S=*/nullptr, Owner, D->getDeclName(), ReductionTypes, D->getAccess(),
2782 auto *NewDRD = cast<OMPDeclareReductionDecl>(DRD.get().getSingleDecl());
2783 if (isDeclWithinFunction(NewDRD))
2784 SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewDRD);
2785 Expr *SubstCombiner = nullptr;
2786 Expr *SubstInitializer = nullptr;
2787 // Combiners instantiation sequence.
2788 if (D->getCombiner()) {
2789 SemaRef.ActOnOpenMPDeclareReductionCombinerStart(
2790 /*S=*/nullptr, NewDRD);
2791 const char *Names[] = {"omp_in", "omp_out"};
2792 for (auto &Name : Names) {
2793 DeclarationName DN(&SemaRef.Context.Idents.get(Name));
2794 auto OldLookup = D->lookup(DN);
2795 auto Lookup = NewDRD->lookup(DN);
2796 if (!OldLookup.empty() && !Lookup.empty()) {
2797 assert(Lookup.size() == 1 && OldLookup.size() == 1);
2798 SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldLookup.front(),
2802 SubstCombiner = SemaRef.SubstExpr(D->getCombiner(), TemplateArgs).get();
2803 SemaRef.ActOnOpenMPDeclareReductionCombinerEnd(NewDRD, SubstCombiner);
2804 // Initializers instantiation sequence.
2805 if (D->getInitializer()) {
2806 VarDecl *OmpPrivParm =
2807 SemaRef.ActOnOpenMPDeclareReductionInitializerStart(
2808 /*S=*/nullptr, NewDRD);
2809 const char *Names[] = {"omp_orig", "omp_priv"};
2810 for (auto &Name : Names) {
2811 DeclarationName DN(&SemaRef.Context.Idents.get(Name));
2812 auto OldLookup = D->lookup(DN);
2813 auto Lookup = NewDRD->lookup(DN);
2814 if (!OldLookup.empty() && !Lookup.empty()) {
2815 assert(Lookup.size() == 1 && OldLookup.size() == 1);
2816 auto *OldVD = cast<VarDecl>(OldLookup.front());
2817 auto *NewVD = cast<VarDecl>(Lookup.front());
2818 SemaRef.InstantiateVariableInitializer(NewVD, OldVD, TemplateArgs);
2819 SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldVD, NewVD);
2822 if (D->getInitializerKind() == OMPDeclareReductionDecl::CallInit) {
2824 SemaRef.SubstExpr(D->getInitializer(), TemplateArgs).get();
2826 IsCorrect = IsCorrect && OmpPrivParm->hasInit();
2828 SemaRef.ActOnOpenMPDeclareReductionInitializerEnd(
2829 NewDRD, SubstInitializer, OmpPrivParm);
2832 IsCorrect && SubstCombiner &&
2833 (!D->getInitializer() ||
2834 (D->getInitializerKind() == OMPDeclareReductionDecl::CallInit &&
2835 SubstInitializer) ||
2836 (D->getInitializerKind() != OMPDeclareReductionDecl::CallInit &&
2837 !SubstInitializer && !SubstInitializer));
2841 (void)SemaRef.ActOnOpenMPDeclareReductionDirectiveEnd(/*S=*/nullptr, DRD,
2847 Decl *TemplateDeclInstantiator::VisitOMPCapturedExprDecl(
2848 OMPCapturedExprDecl * /*D*/) {
2849 llvm_unreachable("Should not be met in templates");
2852 Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D) {
2853 return VisitFunctionDecl(D, nullptr);
2857 TemplateDeclInstantiator::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
2858 return VisitFunctionDecl(D, nullptr);
2861 Decl *TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D) {
2862 return VisitCXXMethodDecl(D, nullptr);
2865 Decl *TemplateDeclInstantiator::VisitRecordDecl(RecordDecl *D) {
2866 llvm_unreachable("There are only CXXRecordDecls in C++");
2870 TemplateDeclInstantiator::VisitClassTemplateSpecializationDecl(
2871 ClassTemplateSpecializationDecl *D) {
2872 // As a MS extension, we permit class-scope explicit specialization
2873 // of member class templates.
2874 ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
2875 assert(ClassTemplate->getDeclContext()->isRecord() &&
2876 D->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
2877 "can only instantiate an explicit specialization "
2878 "for a member class template");
2880 // Lookup the already-instantiated declaration in the instantiation
2881 // of the class template. FIXME: Diagnose or assert if this fails?
2882 DeclContext::lookup_result Found
2883 = Owner->lookup(ClassTemplate->getDeclName());
2886 ClassTemplateDecl *InstClassTemplate
2887 = dyn_cast<ClassTemplateDecl>(Found.front());
2888 if (!InstClassTemplate)
2891 // Substitute into the template arguments of the class template explicit
2893 TemplateSpecializationTypeLoc Loc = D->getTypeAsWritten()->getTypeLoc().
2894 castAs<TemplateSpecializationTypeLoc>();
2895 TemplateArgumentListInfo InstTemplateArgs(Loc.getLAngleLoc(),
2896 Loc.getRAngleLoc());
2897 SmallVector<TemplateArgumentLoc, 4> ArgLocs;
2898 for (unsigned I = 0; I != Loc.getNumArgs(); ++I)
2899 ArgLocs.push_back(Loc.getArgLoc(I));
2900 if (SemaRef.Subst(ArgLocs.data(), ArgLocs.size(),
2901 InstTemplateArgs, TemplateArgs))
2904 // Check that the template argument list is well-formed for this
2906 SmallVector<TemplateArgument, 4> Converted;
2907 if (SemaRef.CheckTemplateArgumentList(InstClassTemplate,
2914 // Figure out where to insert this class template explicit specialization
2915 // in the member template's set of class template explicit specializations.
2916 void *InsertPos = nullptr;
2917 ClassTemplateSpecializationDecl *PrevDecl =
2918 InstClassTemplate->findSpecialization(Converted, InsertPos);
2920 // Check whether we've already seen a conflicting instantiation of this
2921 // declaration (for instance, if there was a prior implicit instantiation).
2924 SemaRef.CheckSpecializationInstantiationRedecl(D->getLocation(),
2925 D->getSpecializationKind(),
2927 PrevDecl->getSpecializationKind(),
2928 PrevDecl->getPointOfInstantiation(),
2932 // If PrevDecl was a definition and D is also a definition, diagnose.
2933 // This happens in cases like:
2935 // template<typename T, typename U>
2937 // template<typename X> struct Inner;
2938 // template<> struct Inner<T> {};
2939 // template<> struct Inner<U> {};
2942 // Outer<int, int> outer; // error: the explicit specializations of Inner
2943 // // have the same signature.
2944 if (PrevDecl && PrevDecl->getDefinition() &&
2945 D->isThisDeclarationADefinition()) {
2946 SemaRef.Diag(D->getLocation(), diag::err_redefinition) << PrevDecl;
2947 SemaRef.Diag(PrevDecl->getDefinition()->getLocation(),
2948 diag::note_previous_definition);
2952 // Create the class template partial specialization declaration.
2953 ClassTemplateSpecializationDecl *InstD
2954 = ClassTemplateSpecializationDecl::Create(SemaRef.Context,
2963 // Add this partial specialization to the set of class template partial
2966 InstClassTemplate->AddSpecialization(InstD, InsertPos);
2968 // Substitute the nested name specifier, if any.
2969 if (SubstQualifier(D, InstD))
2972 // Build the canonical type that describes the converted template
2973 // arguments of the class template explicit specialization.
2974 QualType CanonType = SemaRef.Context.getTemplateSpecializationType(
2975 TemplateName(InstClassTemplate), Converted,
2976 SemaRef.Context.getRecordType(InstD));
2978 // Build the fully-sugared type for this class template
2979 // specialization as the user wrote in the specialization
2980 // itself. This means that we'll pretty-print the type retrieved
2981 // from the specialization's declaration the way that the user
2982 // actually wrote the specialization, rather than formatting the
2983 // name based on the "canonical" representation used to store the
2984 // template arguments in the specialization.
2985 TypeSourceInfo *WrittenTy = SemaRef.Context.getTemplateSpecializationTypeInfo(
2986 TemplateName(InstClassTemplate), D->getLocation(), InstTemplateArgs,
2989 InstD->setAccess(D->getAccess());
2990 InstD->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
2991 InstD->setSpecializationKind(D->getSpecializationKind());
2992 InstD->setTypeAsWritten(WrittenTy);
2993 InstD->setExternLoc(D->getExternLoc());
2994 InstD->setTemplateKeywordLoc(D->getTemplateKeywordLoc());
2996 Owner->addDecl(InstD);
2998 // Instantiate the members of the class-scope explicit specialization eagerly.
2999 // We don't have support for lazy instantiation of an explicit specialization
3000 // yet, and MSVC eagerly instantiates in this case.
3001 if (D->isThisDeclarationADefinition() &&
3002 SemaRef.InstantiateClass(D->getLocation(), InstD, D, TemplateArgs,
3003 TSK_ImplicitInstantiation,
3010 Decl *TemplateDeclInstantiator::VisitVarTemplateSpecializationDecl(
3011 VarTemplateSpecializationDecl *D) {
3013 TemplateArgumentListInfo VarTemplateArgsInfo;
3014 VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
3015 assert(VarTemplate &&
3016 "A template specialization without specialized template?");
3018 // Substitute the current template arguments.
3019 const TemplateArgumentListInfo &TemplateArgsInfo = D->getTemplateArgsInfo();
3020 VarTemplateArgsInfo.setLAngleLoc(TemplateArgsInfo.getLAngleLoc());
3021 VarTemplateArgsInfo.setRAngleLoc(TemplateArgsInfo.getRAngleLoc());
3023 if (SemaRef.Subst(TemplateArgsInfo.getArgumentArray(),
3024 TemplateArgsInfo.size(), VarTemplateArgsInfo, TemplateArgs))
3027 // Check that the template argument list is well-formed for this template.
3028 SmallVector<TemplateArgument, 4> Converted;
3029 if (SemaRef.CheckTemplateArgumentList(
3030 VarTemplate, VarTemplate->getLocStart(),
3031 const_cast<TemplateArgumentListInfo &>(VarTemplateArgsInfo), false,
3035 // Find the variable template specialization declaration that
3036 // corresponds to these arguments.
3037 void *InsertPos = nullptr;
3038 if (VarTemplateSpecializationDecl *VarSpec = VarTemplate->findSpecialization(
3039 Converted, InsertPos))
3040 // If we already have a variable template specialization, return it.
3043 return VisitVarTemplateSpecializationDecl(VarTemplate, D, InsertPos,
3044 VarTemplateArgsInfo, Converted);
3047 Decl *TemplateDeclInstantiator::VisitVarTemplateSpecializationDecl(
3048 VarTemplateDecl *VarTemplate, VarDecl *D, void *InsertPos,
3049 const TemplateArgumentListInfo &TemplateArgsInfo,
3050 ArrayRef<TemplateArgument> Converted) {
3052 // Do substitution on the type of the declaration
3053 TypeSourceInfo *DI =
3054 SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
3055 D->getTypeSpecStartLoc(), D->getDeclName());
3059 if (DI->getType()->isFunctionType()) {
3060 SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
3061 << D->isStaticDataMember() << DI->getType();
3065 // Build the instantiated declaration
3066 VarTemplateSpecializationDecl *Var = VarTemplateSpecializationDecl::Create(
3067 SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
3068 VarTemplate, DI->getType(), DI, D->getStorageClass(), Converted);
3069 Var->setTemplateArgsInfo(TemplateArgsInfo);
3071 VarTemplate->AddSpecialization(Var, InsertPos);
3073 // Substitute the nested name specifier, if any.
3074 if (SubstQualifier(D, Var))
3077 SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs,
3078 Owner, StartingScope);
3083 Decl *TemplateDeclInstantiator::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
3084 llvm_unreachable("@defs is not supported in Objective-C++");
3087 Decl *TemplateDeclInstantiator::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
3088 // FIXME: We need to be able to instantiate FriendTemplateDecls.
3089 unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
3090 DiagnosticsEngine::Error,
3091 "cannot instantiate %0 yet");
3092 SemaRef.Diag(D->getLocation(), DiagID)
3093 << D->getDeclKindName();
3098 Decl *TemplateDeclInstantiator::VisitDecl(Decl *D) {
3099 llvm_unreachable("Unexpected decl");
3102 Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
3103 const MultiLevelTemplateArgumentList &TemplateArgs) {
3104 TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
3105 if (D->isInvalidDecl())
3108 return Instantiator.Visit(D);
3111 /// \brief Instantiates a nested template parameter list in the current
3112 /// instantiation context.
3114 /// \param L The parameter list to instantiate
3116 /// \returns NULL if there was an error
3117 TemplateParameterList *
3118 TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) {
3119 // Get errors for all the parameters before bailing out.
3120 bool Invalid = false;
3122 unsigned N = L->size();
3123 typedef SmallVector<NamedDecl *, 8> ParamVector;
3126 for (auto &P : *L) {
3127 NamedDecl *D = cast_or_null<NamedDecl>(Visit(P));
3128 Params.push_back(D);
3129 Invalid = Invalid || !D || D->isInvalidDecl();
3132 // Clean up if we had an error.
3136 // Note: we substitute into associated constraints later
3137 Expr *const UninstantiatedRequiresClause = L->getRequiresClause();
3139 TemplateParameterList *InstL
3140 = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
3141 L->getLAngleLoc(), Params,
3143 UninstantiatedRequiresClause);
3147 /// \brief Instantiate the declaration of a class template partial
3150 /// \param ClassTemplate the (instantiated) class template that is partially
3151 // specialized by the instantiation of \p PartialSpec.
3153 /// \param PartialSpec the (uninstantiated) class template partial
3154 /// specialization that we are instantiating.
3156 /// \returns The instantiated partial specialization, if successful; otherwise,
3157 /// NULL to indicate an error.
3158 ClassTemplatePartialSpecializationDecl *
3159 TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization(
3160 ClassTemplateDecl *ClassTemplate,
3161 ClassTemplatePartialSpecializationDecl *PartialSpec) {
3162 // Create a local instantiation scope for this class template partial
3163 // specialization, which will contain the instantiations of the template
3165 LocalInstantiationScope Scope(SemaRef);
3167 // Substitute into the template parameters of the class template partial
3169 TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
3170 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
3174 // Substitute into the template arguments of the class template partial
3176 const ASTTemplateArgumentListInfo *TemplArgInfo
3177 = PartialSpec->getTemplateArgsAsWritten();
3178 TemplateArgumentListInfo InstTemplateArgs(TemplArgInfo->LAngleLoc,
3179 TemplArgInfo->RAngleLoc);
3180 if (SemaRef.Subst(TemplArgInfo->getTemplateArgs(),
3181 TemplArgInfo->NumTemplateArgs,
3182 InstTemplateArgs, TemplateArgs))
3185 // Check that the template argument list is well-formed for this
3187 SmallVector<TemplateArgument, 4> Converted;
3188 if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
3189 PartialSpec->getLocation(),
3195 // Check these arguments are valid for a template partial specialization.
3196 if (SemaRef.CheckTemplatePartialSpecializationArgs(
3197 PartialSpec->getLocation(), ClassTemplate, InstTemplateArgs.size(),
3201 // Figure out where to insert this class template partial specialization
3202 // in the member template's set of class template partial specializations.
3203 void *InsertPos = nullptr;
3204 ClassTemplateSpecializationDecl *PrevDecl
3205 = ClassTemplate->findPartialSpecialization(Converted, InsertPos);
3207 // Build the canonical type that describes the converted template
3208 // arguments of the class template partial specialization.
3210 = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
3213 // Build the fully-sugared type for this class template
3214 // specialization as the user wrote in the specialization
3215 // itself. This means that we'll pretty-print the type retrieved
3216 // from the specialization's declaration the way that the user
3217 // actually wrote the specialization, rather than formatting the
3218 // name based on the "canonical" representation used to store the
3219 // template arguments in the specialization.
3220 TypeSourceInfo *WrittenTy
3221 = SemaRef.Context.getTemplateSpecializationTypeInfo(
3222 TemplateName(ClassTemplate),
3223 PartialSpec->getLocation(),
3228 // We've already seen a partial specialization with the same template
3229 // parameters and template arguments. This can happen, for example, when
3230 // substituting the outer template arguments ends up causing two
3231 // class template partial specializations of a member class template
3232 // to have identical forms, e.g.,
3234 // template<typename T, typename U>
3236 // template<typename X, typename Y> struct Inner;
3237 // template<typename Y> struct Inner<T, Y>;
3238 // template<typename Y> struct Inner<U, Y>;
3241 // Outer<int, int> outer; // error: the partial specializations of Inner
3242 // // have the same signature.
3243 SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
3244 << WrittenTy->getType();
3245 SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
3246 << SemaRef.Context.getTypeDeclType(PrevDecl);
3251 // Create the class template partial specialization declaration.
3252 ClassTemplatePartialSpecializationDecl *InstPartialSpec
3253 = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context,
3254 PartialSpec->getTagKind(),
3256 PartialSpec->getLocStart(),
3257 PartialSpec->getLocation(),
3264 // Substitute the nested name specifier, if any.
3265 if (SubstQualifier(PartialSpec, InstPartialSpec))
3268 InstPartialSpec->setInstantiatedFromMember(PartialSpec);
3269 InstPartialSpec->setTypeAsWritten(WrittenTy);
3271 // Check the completed partial specialization.
3272 SemaRef.CheckTemplatePartialSpecialization(InstPartialSpec);
3274 // Add this partial specialization to the set of class template partial
3276 ClassTemplate->AddPartialSpecialization(InstPartialSpec,
3277 /*InsertPos=*/nullptr);
3278 return InstPartialSpec;
3281 /// \brief Instantiate the declaration of a variable template partial
3284 /// \param VarTemplate the (instantiated) variable template that is partially
3285 /// specialized by the instantiation of \p PartialSpec.
3287 /// \param PartialSpec the (uninstantiated) variable template partial
3288 /// specialization that we are instantiating.
3290 /// \returns The instantiated partial specialization, if successful; otherwise,
3291 /// NULL to indicate an error.
3292 VarTemplatePartialSpecializationDecl *
3293 TemplateDeclInstantiator::InstantiateVarTemplatePartialSpecialization(
3294 VarTemplateDecl *VarTemplate,
3295 VarTemplatePartialSpecializationDecl *PartialSpec) {
3296 // Create a local instantiation scope for this variable template partial
3297 // specialization, which will contain the instantiations of the template
3299 LocalInstantiationScope Scope(SemaRef);
3301 // Substitute into the template parameters of the variable template partial
3303 TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
3304 TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
3308 // Substitute into the template arguments of the variable template partial
3310 const ASTTemplateArgumentListInfo *TemplArgInfo
3311 = PartialSpec->getTemplateArgsAsWritten();
3312 TemplateArgumentListInfo InstTemplateArgs(TemplArgInfo->LAngleLoc,
3313 TemplArgInfo->RAngleLoc);
3314 if (SemaRef.Subst(TemplArgInfo->getTemplateArgs(),
3315 TemplArgInfo->NumTemplateArgs,
3316 InstTemplateArgs, TemplateArgs))
3319 // Check that the template argument list is well-formed for this
3321 SmallVector<TemplateArgument, 4> Converted;
3322 if (SemaRef.CheckTemplateArgumentList(VarTemplate, PartialSpec->getLocation(),
3323 InstTemplateArgs, false, Converted))
3326 // Check these arguments are valid for a template partial specialization.
3327 if (SemaRef.CheckTemplatePartialSpecializationArgs(
3328 PartialSpec->getLocation(), VarTemplate, InstTemplateArgs.size(),
3332 // Figure out where to insert this variable template partial specialization
3333 // in the member template's set of variable template partial specializations.
3334 void *InsertPos = nullptr;
3335 VarTemplateSpecializationDecl *PrevDecl =
3336 VarTemplate->findPartialSpecialization(Converted, InsertPos);
3338 // Build the canonical type that describes the converted template
3339 // arguments of the variable template partial specialization.
3340 QualType CanonType = SemaRef.Context.getTemplateSpecializationType(
3341 TemplateName(VarTemplate), Converted);
3343 // Build the fully-sugared type for this variable template
3344 // specialization as the user wrote in the specialization
3345 // itself. This means that we'll pretty-print the type retrieved
3346 // from the specialization's declaration the way that the user
3347 // actually wrote the specialization, rather than formatting the
3348 // name based on the "canonical" representation used to store the
3349 // template arguments in the specialization.
3350 TypeSourceInfo *WrittenTy = SemaRef.Context.getTemplateSpecializationTypeInfo(
3351 TemplateName(VarTemplate), PartialSpec->getLocation(), InstTemplateArgs,
3355 // We've already seen a partial specialization with the same template
3356 // parameters and template arguments. This can happen, for example, when
3357 // substituting the outer template arguments ends up causing two
3358 // variable template partial specializations of a member variable template
3359 // to have identical forms, e.g.,
3361 // template<typename T, typename U>
3363 // template<typename X, typename Y> pair<X,Y> p;
3364 // template<typename Y> pair<T, Y> p;
3365 // template<typename Y> pair<U, Y> p;
3368 // Outer<int, int> outer; // error: the partial specializations of Inner
3369 // // have the same signature.
3370 SemaRef.Diag(PartialSpec->getLocation(),
3371 diag::err_var_partial_spec_redeclared)
3372 << WrittenTy->getType();
3373 SemaRef.Diag(PrevDecl->getLocation(),
3374 diag::note_var_prev_partial_spec_here);
3378 // Do substitution on the type of the declaration
3379 TypeSourceInfo *DI = SemaRef.SubstType(
3380 PartialSpec->getTypeSourceInfo(), TemplateArgs,
3381 PartialSpec->getTypeSpecStartLoc(), PartialSpec->getDeclName());
3385 if (DI->getType()->isFunctionType()) {
3386 SemaRef.Diag(PartialSpec->getLocation(),
3387 diag::err_variable_instantiates_to_function)
3388 << PartialSpec->isStaticDataMember() << DI->getType();
3392 // Create the variable template partial specialization declaration.
3393 VarTemplatePartialSpecializationDecl *InstPartialSpec =
3394 VarTemplatePartialSpecializationDecl::Create(
3395 SemaRef.Context, Owner, PartialSpec->getInnerLocStart(),
3396 PartialSpec->getLocation(), InstParams, VarTemplate, DI->getType(),
3397 DI, PartialSpec->getStorageClass(), Converted, InstTemplateArgs);
3399 // Substitute the nested name specifier, if any.
3400 if (SubstQualifier(PartialSpec, InstPartialSpec))
3403 InstPartialSpec->setInstantiatedFromMember(PartialSpec);
3404 InstPartialSpec->setTypeAsWritten(WrittenTy);
3406 // Check the completed partial specialization.
3407 SemaRef.CheckTemplatePartialSpecialization(InstPartialSpec);
3409 // Add this partial specialization to the set of variable template partial
3410 // specializations. The instantiation of the initializer is not necessary.
3411 VarTemplate->AddPartialSpecialization(InstPartialSpec, /*InsertPos=*/nullptr);
3413 SemaRef.BuildVariableInstantiation(InstPartialSpec, PartialSpec, TemplateArgs,
3414 LateAttrs, Owner, StartingScope);
3416 return InstPartialSpec;
3420 TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D,
3421 SmallVectorImpl<ParmVarDecl *> &Params) {
3422 TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
3423 assert(OldTInfo && "substituting function without type source info");
3424 assert(Params.empty() && "parameter vector is non-empty at start");
3426 CXXRecordDecl *ThisContext = nullptr;
3427 unsigned ThisTypeQuals = 0;
3428 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
3429 ThisContext = cast<CXXRecordDecl>(Owner);
3430 ThisTypeQuals = Method->getTypeQualifiers();
3433 TypeSourceInfo *NewTInfo
3434 = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
3435 D->getTypeSpecStartLoc(),
3437 ThisContext, ThisTypeQuals);
3441 TypeLoc OldTL = OldTInfo->getTypeLoc().IgnoreParens();
3442 if (FunctionProtoTypeLoc OldProtoLoc = OldTL.getAs<FunctionProtoTypeLoc>()) {
3443 if (NewTInfo != OldTInfo) {
3444 // Get parameters from the new type info.
3445 TypeLoc NewTL = NewTInfo->getTypeLoc().IgnoreParens();
3446 FunctionProtoTypeLoc NewProtoLoc = NewTL.castAs<FunctionProtoTypeLoc>();
3447 unsigned NewIdx = 0;
3448 for (unsigned OldIdx = 0, NumOldParams = OldProtoLoc.getNumParams();
3449 OldIdx != NumOldParams; ++OldIdx) {
3450 ParmVarDecl *OldParam = OldProtoLoc.getParam(OldIdx);
3451 LocalInstantiationScope *Scope = SemaRef.CurrentInstantiationScope;
3453 Optional<unsigned> NumArgumentsInExpansion;
3454 if (OldParam->isParameterPack())
3455 NumArgumentsInExpansion =
3456 SemaRef.getNumArgumentsInExpansion(OldParam->getType(),
3458 if (!NumArgumentsInExpansion) {
3459 // Simple case: normal parameter, or a parameter pack that's
3460 // instantiated to a (still-dependent) parameter pack.
3461 ParmVarDecl *NewParam = NewProtoLoc.getParam(NewIdx++);
3462 Params.push_back(NewParam);
3463 Scope->InstantiatedLocal(OldParam, NewParam);
3465 // Parameter pack expansion: make the instantiation an argument pack.
3466 Scope->MakeInstantiatedLocalArgPack(OldParam);
3467 for (unsigned I = 0; I != *NumArgumentsInExpansion; ++I) {
3468 ParmVarDecl *NewParam = NewProtoLoc.getParam(NewIdx++);
3469 Params.push_back(NewParam);
3470 Scope->InstantiatedLocalPackArg(OldParam, NewParam);
3475 // The function type itself was not dependent and therefore no
3476 // substitution occurred. However, we still need to instantiate
3477 // the function parameters themselves.
3478 const FunctionProtoType *OldProto =
3479 cast<FunctionProtoType>(OldProtoLoc.getType());
3480 for (unsigned i = 0, i_end = OldProtoLoc.getNumParams(); i != i_end;
3482 ParmVarDecl *OldParam = OldProtoLoc.getParam(i);
3484 Params.push_back(SemaRef.BuildParmVarDeclForTypedef(
3485 D, D->getLocation(), OldProto->getParamType(i)));
3490 cast_or_null<ParmVarDecl>(VisitParmVarDecl(OldParam));
3493 Params.push_back(Parm);
3497 // If the type of this function, after ignoring parentheses, is not
3498 // *directly* a function type, then we're instantiating a function that
3499 // was declared via a typedef or with attributes, e.g.,
3501 // typedef int functype(int, int);
3503 // int __cdecl meth(int, int);
3505 // In this case, we'll just go instantiate the ParmVarDecls that we
3506 // synthesized in the method declaration.
3507 SmallVector<QualType, 4> ParamTypes;
3508 Sema::ExtParameterInfoBuilder ExtParamInfos;
3509 if (SemaRef.SubstParmTypes(D->getLocation(), D->parameters(), nullptr,
3510 TemplateArgs, ParamTypes, &Params,
3518 /// Introduce the instantiated function parameters into the local
3519 /// instantiation scope, and set the parameter names to those used
3520 /// in the template.
3521 static bool addInstantiatedParametersToScope(Sema &S, FunctionDecl *Function,
3522 const FunctionDecl *PatternDecl,
3523 LocalInstantiationScope &Scope,
3524 const MultiLevelTemplateArgumentList &TemplateArgs) {
3525 unsigned FParamIdx = 0;
3526 for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
3527 const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
3528 if (!PatternParam->isParameterPack()) {
3529 // Simple case: not a parameter pack.
3530 assert(FParamIdx < Function->getNumParams());
3531 ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
3532 FunctionParam->setDeclName(PatternParam->getDeclName());
3533 // If the parameter's type is not dependent, update it to match the type
3534 // in the pattern. They can differ in top-level cv-qualifiers, and we want
3535 // the pattern's type here. If the type is dependent, they can't differ,
3536 // per core issue 1668. Substitute into the type from the pattern, in case
3537 // it's instantiation-dependent.
3538 // FIXME: Updating the type to work around this is at best fragile.
3539 if (!PatternDecl->getType()->isDependentType()) {
3540 QualType T = S.SubstType(PatternParam->getType(), TemplateArgs,
3541 FunctionParam->getLocation(),
3542 FunctionParam->getDeclName());
3545 FunctionParam->setType(T);
3548 Scope.InstantiatedLocal(PatternParam, FunctionParam);
3553 // Expand the parameter pack.
3554 Scope.MakeInstantiatedLocalArgPack(PatternParam);
3555 Optional<unsigned> NumArgumentsInExpansion
3556 = S.getNumArgumentsInExpansion(PatternParam->getType(), TemplateArgs);
3557 assert(NumArgumentsInExpansion &&
3558 "should only be called when all template arguments are known");
3559 QualType PatternType =
3560 PatternParam->getType()->castAs<PackExpansionType>()->getPattern();
3561 for (unsigned Arg = 0; Arg < *NumArgumentsInExpansion; ++Arg) {
3562 ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
3563 FunctionParam->setDeclName(PatternParam->getDeclName());
3564 if (!PatternDecl->getType()->isDependentType()) {
3565 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, Arg);
3566 QualType T = S.SubstType(PatternType, TemplateArgs,
3567 FunctionParam->getLocation(),
3568 FunctionParam->getDeclName());
3571 FunctionParam->setType(T);
3574 Scope.InstantiatedLocalPackArg(PatternParam, FunctionParam);
3582 void Sema::InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
3583 FunctionDecl *Decl) {
3584 const FunctionProtoType *Proto = Decl->getType()->castAs<FunctionProtoType>();
3585 if (Proto->getExceptionSpecType() != EST_Uninstantiated)
3588 InstantiatingTemplate Inst(*this, PointOfInstantiation, Decl,
3589 InstantiatingTemplate::ExceptionSpecification());
3590 if (Inst.isInvalid()) {
3591 // We hit the instantiation depth limit. Clear the exception specification
3592 // so that our callers don't have to cope with EST_Uninstantiated.
3593 UpdateExceptionSpec(Decl, EST_None);
3596 if (Inst.isAlreadyInstantiating()) {
3597 // This exception specification indirectly depends on itself. Reject.
3598 // FIXME: Corresponding rule in the standard?
3599 Diag(PointOfInstantiation, diag::err_exception_spec_cycle) << Decl;
3600 UpdateExceptionSpec(Decl, EST_None);
3604 // Enter the scope of this instantiation. We don't use
3605 // PushDeclContext because we don't have a scope.
3606 Sema::ContextRAII savedContext(*this, Decl);
3607 LocalInstantiationScope Scope(*this);
3609 MultiLevelTemplateArgumentList TemplateArgs =
3610 getTemplateInstantiationArgs(Decl, nullptr, /*RelativeToPrimary*/true);
3612 FunctionDecl *Template = Proto->getExceptionSpecTemplate();
3613 if (addInstantiatedParametersToScope(*this, Decl, Template, Scope,
3615 UpdateExceptionSpec(Decl, EST_None);
3619 SubstExceptionSpec(Decl, Template->getType()->castAs<FunctionProtoType>(),
3623 /// \brief Initializes the common fields of an instantiation function
3624 /// declaration (New) from the corresponding fields of its template (Tmpl).
3626 /// \returns true if there was an error
3628 TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
3629 FunctionDecl *Tmpl) {
3630 if (Tmpl->isDeleted())
3631 New->setDeletedAsWritten();
3633 New->setImplicit(Tmpl->isImplicit());
3635 // Forward the mangling number from the template to the instantiated decl.
3636 SemaRef.Context.setManglingNumber(New,
3637 SemaRef.Context.getManglingNumber(Tmpl));
3639 // If we are performing substituting explicitly-specified template arguments
3640 // or deduced template arguments into a function template and we reach this
3641 // point, we are now past the point where SFINAE applies and have committed
3642 // to keeping the new function template specialization. We therefore
3643 // convert the active template instantiation for the function template
3644 // into a template instantiation for this specific function template
3645 // specialization, which is not a SFINAE context, so that we diagnose any
3646 // further errors in the declaration itself.
3647 typedef Sema::CodeSynthesisContext ActiveInstType;
3648 ActiveInstType &ActiveInst = SemaRef.CodeSynthesisContexts.back();
3649 if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
3650 ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
3651 if (FunctionTemplateDecl *FunTmpl
3652 = dyn_cast<FunctionTemplateDecl>(ActiveInst.Entity)) {
3653 assert(FunTmpl->getTemplatedDecl() == Tmpl &&
3654 "Deduction from the wrong function template?");
3656 ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
3657 ActiveInst.Entity = New;
3661 const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
3662 assert(Proto && "Function template without prototype?");
3664 if (Proto->hasExceptionSpec() || Proto->getNoReturnAttr()) {
3665 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
3667 // DR1330: In C++11, defer instantiation of a non-trivial
3668 // exception specification.
3669 // DR1484: Local classes and their members are instantiated along with the
3670 // containing function.
3671 if (SemaRef.getLangOpts().CPlusPlus11 &&
3672 EPI.ExceptionSpec.Type != EST_None &&
3673 EPI.ExceptionSpec.Type != EST_DynamicNone &&
3674 EPI.ExceptionSpec.Type != EST_BasicNoexcept &&
3675 !Tmpl->isLexicallyWithinFunctionOrMethod()) {
3676 FunctionDecl *ExceptionSpecTemplate = Tmpl;
3677 if (EPI.ExceptionSpec.Type == EST_Uninstantiated)
3678 ExceptionSpecTemplate = EPI.ExceptionSpec.SourceTemplate;
3679 ExceptionSpecificationType NewEST = EST_Uninstantiated;
3680 if (EPI.ExceptionSpec.Type == EST_Unevaluated)
3681 NewEST = EST_Unevaluated;
3683 // Mark the function has having an uninstantiated exception specification.
3684 const FunctionProtoType *NewProto
3685 = New->getType()->getAs<FunctionProtoType>();
3686 assert(NewProto && "Template instantiation without function prototype?");
3687 EPI = NewProto->getExtProtoInfo();
3688 EPI.ExceptionSpec.Type = NewEST;
3689 EPI.ExceptionSpec.SourceDecl = New;
3690 EPI.ExceptionSpec.SourceTemplate = ExceptionSpecTemplate;
3691 New->setType(SemaRef.Context.getFunctionType(
3692 NewProto->getReturnType(), NewProto->getParamTypes(), EPI));
3694 Sema::ContextRAII SwitchContext(SemaRef, New);
3695 SemaRef.SubstExceptionSpec(New, Proto, TemplateArgs);
3699 // Get the definition. Leaves the variable unchanged if undefined.
3700 const FunctionDecl *Definition = Tmpl;
3701 Tmpl->isDefined(Definition);
3703 SemaRef.InstantiateAttrs(TemplateArgs, Definition, New,
3704 LateAttrs, StartingScope);
3709 /// \brief Initializes common fields of an instantiated method
3710 /// declaration (New) from the corresponding fields of its template
3713 /// \returns true if there was an error
3715 TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
3716 CXXMethodDecl *Tmpl) {
3717 if (InitFunctionInstantiation(New, Tmpl))
3720 New->setAccess(Tmpl->getAccess());
3721 if (Tmpl->isVirtualAsWritten())
3722 New->setVirtualAsWritten(true);
3724 // FIXME: New needs a pointer to Tmpl
3728 /// In the MS ABI, we need to instantiate default arguments of dllexported
3729 /// default constructors along with the constructor definition. This allows IR
3730 /// gen to emit a constructor closure which calls the default constructor with
3731 /// its default arguments.
3732 static void InstantiateDefaultCtorDefaultArgs(Sema &S,
3733 CXXConstructorDecl *Ctor) {
3734 assert(S.Context.getTargetInfo().getCXXABI().isMicrosoft() &&
3735 Ctor->isDefaultConstructor());
3736 unsigned NumParams = Ctor->getNumParams();
3739 DLLExportAttr *Attr = Ctor->getAttr<DLLExportAttr>();
3742 for (unsigned I = 0; I != NumParams; ++I) {
3743 (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), Ctor,
3744 Ctor->getParamDecl(I));
3745 S.DiscardCleanupsInEvaluationContext();
3749 /// \brief Instantiate the definition of the given function from its
3752 /// \param PointOfInstantiation the point at which the instantiation was
3753 /// required. Note that this is not precisely a "point of instantiation"
3754 /// for the function, but it's close.
3756 /// \param Function the already-instantiated declaration of a
3757 /// function template specialization or member function of a class template
3760 /// \param Recursive if true, recursively instantiates any functions that
3761 /// are required by this instantiation.
3763 /// \param DefinitionRequired if true, then we are performing an explicit
3764 /// instantiation where the body of the function is required. Complain if
3765 /// there is no such body.
3766 void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
3767 FunctionDecl *Function,
3769 bool DefinitionRequired,
3771 if (Function->isInvalidDecl() || Function->isDefined() ||
3772 isa<CXXDeductionGuideDecl>(Function))
3775 // Never instantiate an explicit specialization except if it is a class scope
3776 // explicit specialization.
3777 TemplateSpecializationKind TSK = Function->getTemplateSpecializationKind();
3778 if (TSK == TSK_ExplicitSpecialization &&
3779 !Function->getClassScopeSpecializationPattern())
3782 // Find the function body that we'll be substituting.
3783 const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
3784 assert(PatternDecl && "instantiating a non-template");
3786 const FunctionDecl *PatternDef = PatternDecl->getDefinition();
3787 Stmt *Pattern = nullptr;
3789 Pattern = PatternDef->getBody(PatternDef);
3790 PatternDecl = PatternDef;
3791 if (PatternDef->willHaveBody())
3792 PatternDef = nullptr;
3795 // FIXME: We need to track the instantiation stack in order to know which
3796 // definitions should be visible within this instantiation.
3797 if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Function,
3798 Function->getInstantiatedFromMemberFunction(),
3799 PatternDecl, PatternDef, TSK,
3800 /*Complain*/DefinitionRequired)) {
3801 if (DefinitionRequired)
3802 Function->setInvalidDecl();
3803 else if (TSK == TSK_ExplicitInstantiationDefinition) {
3804 // Try again at the end of the translation unit (at which point a
3805 // definition will be required).
3807 Function->setInstantiationIsPending(true);
3808 PendingInstantiations.push_back(
3809 std::make_pair(Function, PointOfInstantiation));
3810 } else if (TSK == TSK_ImplicitInstantiation) {
3811 if (AtEndOfTU && !getDiagnostics().hasErrorOccurred()) {
3812 Diag(PointOfInstantiation, diag::warn_func_template_missing)
3814 Diag(PatternDecl->getLocation(), diag::note_forward_template_decl);
3815 if (getLangOpts().CPlusPlus11)
3816 Diag(PointOfInstantiation, diag::note_inst_declaration_hint)
3824 // Postpone late parsed template instantiations.
3825 if (PatternDecl->isLateTemplateParsed() &&
3826 !LateTemplateParser) {
3827 Function->setInstantiationIsPending(true);
3828 PendingInstantiations.push_back(
3829 std::make_pair(Function, PointOfInstantiation));
3833 // If we're performing recursive template instantiation, create our own
3834 // queue of pending implicit instantiations that we will instantiate later,
3835 // while we're still within our own instantiation context.
3836 // This has to happen before LateTemplateParser below is called, so that
3837 // it marks vtables used in late parsed templates as used.
3838 GlobalEagerInstantiationScope GlobalInstantiations(*this,
3839 /*Enabled=*/Recursive);
3840 LocalEagerInstantiationScope LocalInstantiations(*this);
3842 // Call the LateTemplateParser callback if there is a need to late parse
3843 // a templated function definition.
3844 if (!Pattern && PatternDecl->isLateTemplateParsed() &&
3845 LateTemplateParser) {
3846 // FIXME: Optimize to allow individual templates to be deserialized.
3847 if (PatternDecl->isFromASTFile())
3848 ExternalSource->ReadLateParsedTemplates(LateParsedTemplateMap);
3850 auto LPTIter = LateParsedTemplateMap.find(PatternDecl);
3851 assert(LPTIter != LateParsedTemplateMap.end() &&
3852 "missing LateParsedTemplate");
3853 LateTemplateParser(OpaqueParser, *LPTIter->second);
3854 Pattern = PatternDecl->getBody(PatternDecl);
3857 // Note, we should never try to instantiate a deleted function template.
3858 assert((Pattern || PatternDecl->isDefaulted()) &&
3859 "unexpected kind of function template definition");
3861 // C++1y [temp.explicit]p10:
3862 // Except for inline functions, declarations with types deduced from their
3863 // initializer or return value, and class template specializations, other
3864 // explicit instantiation declarations have the effect of suppressing the
3865 // implicit instantiation of the entity to which they refer.
3866 if (TSK == TSK_ExplicitInstantiationDeclaration &&
3867 !PatternDecl->isInlined() &&
3868 !PatternDecl->getReturnType()->getContainedAutoType())
3871 if (PatternDecl->isInlined()) {
3872 // Function, and all later redeclarations of it (from imported modules,
3873 // for instance), are now implicitly inline.
3874 for (auto *D = Function->getMostRecentDecl(); /**/;
3875 D = D->getPreviousDecl()) {
3876 D->setImplicitlyInline();
3882 InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
3883 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
3885 PrettyDeclStackTraceEntry CrashInfo(*this, Function, SourceLocation(),
3886 "instantiating function definition");
3888 // The instantiation is visible here, even if it was first declared in an
3889 // unimported module.
3890 Function->setVisibleDespiteOwningModule();
3892 // Copy the inner loc start from the pattern.
3893 Function->setInnerLocStart(PatternDecl->getInnerLocStart());
3895 EnterExpressionEvaluationContext EvalContext(
3896 *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
3898 // Introduce a new scope where local variable instantiations will be
3899 // recorded, unless we're actually a member function within a local
3900 // class, in which case we need to merge our results with the parent
3901 // scope (of the enclosing function).
3902 bool MergeWithParentScope = false;
3903 if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
3904 MergeWithParentScope = Rec->isLocalClass();
3906 LocalInstantiationScope Scope(*this, MergeWithParentScope);
3908 if (PatternDecl->isDefaulted())
3909 SetDeclDefaulted(Function, PatternDecl->getLocation());
3911 MultiLevelTemplateArgumentList TemplateArgs =
3912 getTemplateInstantiationArgs(Function, nullptr, false, PatternDecl);
3914 // Substitute into the qualifier; we can get a substitution failure here
3915 // through evil use of alias templates.
3916 // FIXME: Is CurContext correct for this? Should we go to the (instantiation
3917 // of the) lexical context of the pattern?
3918 SubstQualifier(*this, PatternDecl, Function, TemplateArgs);
3920 ActOnStartOfFunctionDef(nullptr, Function);
3922 // Enter the scope of this instantiation. We don't use
3923 // PushDeclContext because we don't have a scope.
3924 Sema::ContextRAII savedContext(*this, Function);
3926 if (addInstantiatedParametersToScope(*this, Function, PatternDecl, Scope,
3930 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Function)) {
3931 // If this is a constructor, instantiate the member initializers.
3932 InstantiateMemInitializers(Ctor, cast<CXXConstructorDecl>(PatternDecl),
3935 // If this is an MS ABI dllexport default constructor, instantiate any
3936 // default arguments.
3937 if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
3938 Ctor->isDefaultConstructor()) {
3939 InstantiateDefaultCtorDefaultArgs(*this, Ctor);
3943 // Instantiate the function body.
3944 StmtResult Body = SubstStmt(Pattern, TemplateArgs);
3946 if (Body.isInvalid())
3947 Function->setInvalidDecl();
3949 // FIXME: finishing the function body while in an expression evaluation
3950 // context seems wrong. Investigate more.
3951 ActOnFinishFunctionBody(Function, Body.get(),
3952 /*IsInstantiation=*/true);
3954 PerformDependentDiagnostics(PatternDecl, TemplateArgs);
3956 if (auto *Listener = getASTMutationListener())
3957 Listener->FunctionDefinitionInstantiated(Function);
3962 DeclGroupRef DG(Function);
3963 Consumer.HandleTopLevelDecl(DG);
3965 // This class may have local implicit instantiations that need to be
3966 // instantiation within this scope.
3967 LocalInstantiations.perform();
3969 GlobalInstantiations.perform();
3972 VarTemplateSpecializationDecl *Sema::BuildVarTemplateInstantiation(
3973 VarTemplateDecl *VarTemplate, VarDecl *FromVar,
3974 const TemplateArgumentList &TemplateArgList,
3975 const TemplateArgumentListInfo &TemplateArgsInfo,
3976 SmallVectorImpl<TemplateArgument> &Converted,
3977 SourceLocation PointOfInstantiation, void *InsertPos,
3978 LateInstantiatedAttrVec *LateAttrs,
3979 LocalInstantiationScope *StartingScope) {
3980 if (FromVar->isInvalidDecl())
3983 InstantiatingTemplate Inst(*this, PointOfInstantiation, FromVar);
3984 if (Inst.isInvalid())
3987 MultiLevelTemplateArgumentList TemplateArgLists;
3988 TemplateArgLists.addOuterTemplateArguments(&TemplateArgList);
3990 // Instantiate the first declaration of the variable template: for a partial
3991 // specialization of a static data member template, the first declaration may
3992 // or may not be the declaration in the class; if it's in the class, we want
3993 // to instantiate a member in the class (a declaration), and if it's outside,
3994 // we want to instantiate a definition.
3996 // If we're instantiating an explicitly-specialized member template or member
3997 // partial specialization, don't do this. The member specialization completely
3998 // replaces the original declaration in this case.
3999 bool IsMemberSpec = false;
4000 if (VarTemplatePartialSpecializationDecl *PartialSpec =
4001 dyn_cast<VarTemplatePartialSpecializationDecl>(FromVar))
4002 IsMemberSpec = PartialSpec->isMemberSpecialization();
4003 else if (VarTemplateDecl *FromTemplate = FromVar->getDescribedVarTemplate())
4004 IsMemberSpec = FromTemplate->isMemberSpecialization();
4006 FromVar = FromVar->getFirstDecl();
4008 MultiLevelTemplateArgumentList MultiLevelList(TemplateArgList);
4009 TemplateDeclInstantiator Instantiator(*this, FromVar->getDeclContext(),
4012 // TODO: Set LateAttrs and StartingScope ...
4014 return cast_or_null<VarTemplateSpecializationDecl>(
4015 Instantiator.VisitVarTemplateSpecializationDecl(
4016 VarTemplate, FromVar, InsertPos, TemplateArgsInfo, Converted));
4019 /// \brief Instantiates a variable template specialization by completing it
4020 /// with appropriate type information and initializer.
4021 VarTemplateSpecializationDecl *Sema::CompleteVarTemplateSpecializationDecl(
4022 VarTemplateSpecializationDecl *VarSpec, VarDecl *PatternDecl,
4023 const MultiLevelTemplateArgumentList &TemplateArgs) {
4024 assert(PatternDecl->isThisDeclarationADefinition() &&
4025 "don't have a definition to instantiate from");
4027 // Do substitution on the type of the declaration
4028 TypeSourceInfo *DI =
4029 SubstType(PatternDecl->getTypeSourceInfo(), TemplateArgs,
4030 PatternDecl->getTypeSpecStartLoc(), PatternDecl->getDeclName());
4034 // Update the type of this variable template specialization.
4035 VarSpec->setType(DI->getType());
4037 // Convert the declaration into a definition now.
4038 VarSpec->setCompleteDefinition();
4040 // Instantiate the initializer.
4041 InstantiateVariableInitializer(VarSpec, PatternDecl, TemplateArgs);
4046 /// BuildVariableInstantiation - Used after a new variable has been created.
4047 /// Sets basic variable data and decides whether to postpone the
4048 /// variable instantiation.
4049 void Sema::BuildVariableInstantiation(
4050 VarDecl *NewVar, VarDecl *OldVar,
4051 const MultiLevelTemplateArgumentList &TemplateArgs,
4052 LateInstantiatedAttrVec *LateAttrs, DeclContext *Owner,
4053 LocalInstantiationScope *StartingScope,
4054 bool InstantiatingVarTemplate) {
4056 // If we are instantiating a local extern declaration, the
4057 // instantiation belongs lexically to the containing function.
4058 // If we are instantiating a static data member defined
4059 // out-of-line, the instantiation will have the same lexical
4060 // context (which will be a namespace scope) as the template.
4061 if (OldVar->isLocalExternDecl()) {
4062 NewVar->setLocalExternDecl();
4063 NewVar->setLexicalDeclContext(Owner);
4064 } else if (OldVar->isOutOfLine())
4065 NewVar->setLexicalDeclContext(OldVar->getLexicalDeclContext());
4066 NewVar->setTSCSpec(OldVar->getTSCSpec());
4067 NewVar->setInitStyle(OldVar->getInitStyle());
4068 NewVar->setCXXForRangeDecl(OldVar->isCXXForRangeDecl());
4069 NewVar->setConstexpr(OldVar->isConstexpr());
4070 NewVar->setInitCapture(OldVar->isInitCapture());
4071 NewVar->setPreviousDeclInSameBlockScope(
4072 OldVar->isPreviousDeclInSameBlockScope());
4073 NewVar->setAccess(OldVar->getAccess());
4075 if (!OldVar->isStaticDataMember()) {
4076 if (OldVar->isUsed(false))
4077 NewVar->setIsUsed();
4078 NewVar->setReferenced(OldVar->isReferenced());
4081 InstantiateAttrs(TemplateArgs, OldVar, NewVar, LateAttrs, StartingScope);
4083 LookupResult Previous(
4084 *this, NewVar->getDeclName(), NewVar->getLocation(),
4085 NewVar->isLocalExternDecl() ? Sema::LookupRedeclarationWithLinkage
4086 : Sema::LookupOrdinaryName,
4087 NewVar->isLocalExternDecl() ? Sema::ForExternalRedeclaration
4088 : forRedeclarationInCurContext());
4090 if (NewVar->isLocalExternDecl() && OldVar->getPreviousDecl() &&
4091 (!OldVar->getPreviousDecl()->getDeclContext()->isDependentContext() ||
4092 OldVar->getPreviousDecl()->getDeclContext()==OldVar->getDeclContext())) {
4093 // We have a previous declaration. Use that one, so we merge with the
4095 if (NamedDecl *NewPrev = FindInstantiatedDecl(
4096 NewVar->getLocation(), OldVar->getPreviousDecl(), TemplateArgs))
4097 Previous.addDecl(NewPrev);
4098 } else if (!isa<VarTemplateSpecializationDecl>(NewVar) &&
4099 OldVar->hasLinkage())
4100 LookupQualifiedName(Previous, NewVar->getDeclContext(), false);
4101 CheckVariableDeclaration(NewVar, Previous);
4103 if (!InstantiatingVarTemplate) {
4104 NewVar->getLexicalDeclContext()->addHiddenDecl(NewVar);
4105 if (!NewVar->isLocalExternDecl() || !NewVar->getPreviousDecl())
4106 NewVar->getDeclContext()->makeDeclVisibleInContext(NewVar);
4109 if (!OldVar->isOutOfLine()) {
4110 if (NewVar->getDeclContext()->isFunctionOrMethod())
4111 CurrentInstantiationScope->InstantiatedLocal(OldVar, NewVar);
4114 // Link instantiations of static data members back to the template from
4115 // which they were instantiated.
4116 if (NewVar->isStaticDataMember() && !InstantiatingVarTemplate)
4117 NewVar->setInstantiationOfStaticDataMember(OldVar,
4118 TSK_ImplicitInstantiation);
4120 // Forward the mangling number from the template to the instantiated decl.
4121 Context.setManglingNumber(NewVar, Context.getManglingNumber(OldVar));
4122 Context.setStaticLocalNumber(NewVar, Context.getStaticLocalNumber(OldVar));
4124 // Delay instantiation of the initializer for variable templates or inline
4125 // static data members until a definition of the variable is needed. We need
4126 // it right away if the type contains 'auto'.
4127 if ((!isa<VarTemplateSpecializationDecl>(NewVar) &&
4128 !InstantiatingVarTemplate &&
4129 !(OldVar->isInline() && OldVar->isThisDeclarationADefinition())) ||
4130 NewVar->getType()->isUndeducedType())
4131 InstantiateVariableInitializer(NewVar, OldVar, TemplateArgs);
4133 // Diagnose unused local variables with dependent types, where the diagnostic
4134 // will have been deferred.
4135 if (!NewVar->isInvalidDecl() &&
4136 NewVar->getDeclContext()->isFunctionOrMethod() &&
4137 OldVar->getType()->isDependentType())
4138 DiagnoseUnusedDecl(NewVar);
4141 /// \brief Instantiate the initializer of a variable.
4142 void Sema::InstantiateVariableInitializer(
4143 VarDecl *Var, VarDecl *OldVar,
4144 const MultiLevelTemplateArgumentList &TemplateArgs) {
4145 if (ASTMutationListener *L = getASTContext().getASTMutationListener())
4146 L->VariableDefinitionInstantiated(Var);
4148 // We propagate the 'inline' flag with the initializer, because it
4149 // would otherwise imply that the variable is a definition for a
4150 // non-static data member.
4151 if (OldVar->isInlineSpecified())
4152 Var->setInlineSpecified();
4153 else if (OldVar->isInline())
4154 Var->setImplicitlyInline();
4156 if (OldVar->getInit()) {
4157 EnterExpressionEvaluationContext Evaluated(
4158 *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated, Var);
4160 // Instantiate the initializer.
4164 ContextRAII SwitchContext(*this, Var->getDeclContext());
4165 Init = SubstInitializer(OldVar->getInit(), TemplateArgs,
4166 OldVar->getInitStyle() == VarDecl::CallInit);
4169 if (!Init.isInvalid()) {
4170 Expr *InitExpr = Init.get();
4172 if (Var->hasAttr<DLLImportAttr>() &&
4174 !InitExpr->isConstantInitializer(getASTContext(), false))) {
4175 // Do not dynamically initialize dllimport variables.
4176 } else if (InitExpr) {
4177 bool DirectInit = OldVar->isDirectInit();
4178 AddInitializerToDecl(Var, InitExpr, DirectInit);
4180 ActOnUninitializedDecl(Var);
4182 // FIXME: Not too happy about invalidating the declaration
4183 // because of a bogus initializer.
4184 Var->setInvalidDecl();
4187 if (Var->isStaticDataMember()) {
4188 if (!Var->isOutOfLine())
4191 // If the declaration inside the class had an initializer, don't add
4192 // another one to the out-of-line definition.
4193 if (OldVar->getFirstDecl()->hasInit())
4197 // We'll add an initializer to a for-range declaration later.
4198 if (Var->isCXXForRangeDecl())
4201 ActOnUninitializedDecl(Var);
4205 /// \brief Instantiate the definition of the given variable from its
4208 /// \param PointOfInstantiation the point at which the instantiation was
4209 /// required. Note that this is not precisely a "point of instantiation"
4210 /// for the variable, but it's close.
4212 /// \param Var the already-instantiated declaration of a templated variable.
4214 /// \param Recursive if true, recursively instantiates any functions that
4215 /// are required by this instantiation.
4217 /// \param DefinitionRequired if true, then we are performing an explicit
4218 /// instantiation where a definition of the variable is required. Complain
4219 /// if there is no such definition.
4220 void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
4221 VarDecl *Var, bool Recursive,
4222 bool DefinitionRequired, bool AtEndOfTU) {
4223 if (Var->isInvalidDecl())
4226 VarTemplateSpecializationDecl *VarSpec =
4227 dyn_cast<VarTemplateSpecializationDecl>(Var);
4228 VarDecl *PatternDecl = nullptr, *Def = nullptr;
4229 MultiLevelTemplateArgumentList TemplateArgs =
4230 getTemplateInstantiationArgs(Var);
4233 // If this is a variable template specialization, make sure that it is
4234 // non-dependent, then find its instantiation pattern.
4235 bool InstantiationDependent = false;
4236 assert(!TemplateSpecializationType::anyDependentTemplateArguments(
4237 VarSpec->getTemplateArgsInfo(), InstantiationDependent) &&
4238 "Only instantiate variable template specializations that are "
4239 "not type-dependent");
4240 (void)InstantiationDependent;
4242 // Find the variable initialization that we'll be substituting. If the
4243 // pattern was instantiated from a member template, look back further to
4244 // find the real pattern.
4245 assert(VarSpec->getSpecializedTemplate() &&
4246 "Specialization without specialized template?");
4247 llvm::PointerUnion<VarTemplateDecl *,
4248 VarTemplatePartialSpecializationDecl *> PatternPtr =
4249 VarSpec->getSpecializedTemplateOrPartial();
4250 if (PatternPtr.is<VarTemplatePartialSpecializationDecl *>()) {
4251 VarTemplatePartialSpecializationDecl *Tmpl =
4252 PatternPtr.get<VarTemplatePartialSpecializationDecl *>();
4253 while (VarTemplatePartialSpecializationDecl *From =
4254 Tmpl->getInstantiatedFromMember()) {
4255 if (Tmpl->isMemberSpecialization())
4262 VarTemplateDecl *Tmpl = PatternPtr.get<VarTemplateDecl *>();
4263 while (VarTemplateDecl *From =
4264 Tmpl->getInstantiatedFromMemberTemplate()) {
4265 if (Tmpl->isMemberSpecialization())
4270 PatternDecl = Tmpl->getTemplatedDecl();
4273 // If this is a static data member template, there might be an
4274 // uninstantiated initializer on the declaration. If so, instantiate
4277 // FIXME: This largely duplicates what we would do below. The difference
4278 // is that along this path we may instantiate an initializer from an
4279 // in-class declaration of the template and instantiate the definition
4280 // from a separate out-of-class definition.
4281 if (PatternDecl->isStaticDataMember() &&
4282 (PatternDecl = PatternDecl->getFirstDecl())->hasInit() &&
4284 // FIXME: Factor out the duplicated instantiation context setup/tear down
4286 InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
4287 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
4289 PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
4290 "instantiating variable initializer");
4292 // The instantiation is visible here, even if it was first declared in an
4293 // unimported module.
4294 Var->setVisibleDespiteOwningModule();
4296 // If we're performing recursive template instantiation, create our own
4297 // queue of pending implicit instantiations that we will instantiate
4298 // later, while we're still within our own instantiation context.
4299 GlobalEagerInstantiationScope GlobalInstantiations(*this,
4300 /*Enabled=*/Recursive);
4301 LocalInstantiationScope Local(*this);
4302 LocalEagerInstantiationScope LocalInstantiations(*this);
4304 // Enter the scope of this instantiation. We don't use
4305 // PushDeclContext because we don't have a scope.
4306 ContextRAII PreviousContext(*this, Var->getDeclContext());
4307 InstantiateVariableInitializer(Var, PatternDecl, TemplateArgs);
4308 PreviousContext.pop();
4310 // This variable may have local implicit instantiations that need to be
4311 // instantiated within this scope.
4312 LocalInstantiations.perform();
4314 GlobalInstantiations.perform();
4317 // Find actual definition
4318 Def = PatternDecl->getDefinition(getASTContext());
4320 // If this is a static data member, find its out-of-line definition.
4321 assert(Var->isStaticDataMember() && "not a static data member?");
4322 PatternDecl = Var->getInstantiatedFromStaticDataMember();
4324 assert(PatternDecl && "data member was not instantiated from a template?");
4325 assert(PatternDecl->isStaticDataMember() && "not a static data member?");
4326 Def = PatternDecl->getDefinition();
4329 TemplateSpecializationKind TSK = Var->getTemplateSpecializationKind();
4331 // If we don't have a definition of the variable template, we won't perform
4332 // any instantiation. Rather, we rely on the user to instantiate this
4333 // definition (or provide a specialization for it) in another translation
4335 if (!Def && !DefinitionRequired) {
4336 if (TSK == TSK_ExplicitInstantiationDefinition) {
4337 PendingInstantiations.push_back(
4338 std::make_pair(Var, PointOfInstantiation));
4339 } else if (TSK == TSK_ImplicitInstantiation) {
4340 // Warn about missing definition at the end of translation unit.
4341 if (AtEndOfTU && !getDiagnostics().hasErrorOccurred()) {
4342 Diag(PointOfInstantiation, diag::warn_var_template_missing)
4344 Diag(PatternDecl->getLocation(), diag::note_forward_template_decl);
4345 if (getLangOpts().CPlusPlus11)
4346 Diag(PointOfInstantiation, diag::note_inst_declaration_hint) << Var;
4353 // FIXME: We need to track the instantiation stack in order to know which
4354 // definitions should be visible within this instantiation.
4355 // FIXME: Produce diagnostics when Var->getInstantiatedFromStaticDataMember().
4356 if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Var,
4357 /*InstantiatedFromMember*/false,
4358 PatternDecl, Def, TSK,
4359 /*Complain*/DefinitionRequired))
4363 // Never instantiate an explicit specialization.
4364 if (TSK == TSK_ExplicitSpecialization)
4367 // C++11 [temp.explicit]p10:
4368 // Except for inline functions, const variables of literal types, variables
4369 // of reference types, [...] explicit instantiation declarations
4370 // have the effect of suppressing the implicit instantiation of the entity
4371 // to which they refer.
4372 if (TSK == TSK_ExplicitInstantiationDeclaration &&
4373 !Var->isUsableInConstantExpressions(getASTContext()))
4376 // Make sure to pass the instantiated variable to the consumer at the end.
4377 struct PassToConsumerRAII {
4378 ASTConsumer &Consumer;
4381 PassToConsumerRAII(ASTConsumer &Consumer, VarDecl *Var)
4382 : Consumer(Consumer), Var(Var) { }
4384 ~PassToConsumerRAII() {
4385 Consumer.HandleCXXStaticMemberVarInstantiation(Var);
4387 } PassToConsumerRAII(Consumer, Var);
4389 // If we already have a definition, we're done.
4390 if (VarDecl *Def = Var->getDefinition()) {
4391 // We may be explicitly instantiating something we've already implicitly
4393 Def->setTemplateSpecializationKind(Var->getTemplateSpecializationKind(),
4394 PointOfInstantiation);
4398 InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
4399 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
4401 PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
4402 "instantiating variable definition");
4404 // If we're performing recursive template instantiation, create our own
4405 // queue of pending implicit instantiations that we will instantiate later,
4406 // while we're still within our own instantiation context.
4407 GlobalEagerInstantiationScope GlobalInstantiations(*this,
4408 /*Enabled=*/Recursive);
4410 // Enter the scope of this instantiation. We don't use
4411 // PushDeclContext because we don't have a scope.
4412 ContextRAII PreviousContext(*this, Var->getDeclContext());
4413 LocalInstantiationScope Local(*this);
4415 LocalEagerInstantiationScope LocalInstantiations(*this);
4417 VarDecl *OldVar = Var;
4418 if (Def->isStaticDataMember() && !Def->isOutOfLine()) {
4419 // We're instantiating an inline static data member whose definition was
4420 // provided inside the class.
4421 InstantiateVariableInitializer(Var, Def, TemplateArgs);
4422 } else if (!VarSpec) {
4423 Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
4425 } else if (Var->isStaticDataMember() &&
4426 Var->getLexicalDeclContext()->isRecord()) {
4427 // We need to instantiate the definition of a static data member template,
4428 // and all we have is the in-class declaration of it. Instantiate a separate
4429 // declaration of the definition.
4430 TemplateDeclInstantiator Instantiator(*this, Var->getDeclContext(),
4432 Var = cast_or_null<VarDecl>(Instantiator.VisitVarTemplateSpecializationDecl(
4433 VarSpec->getSpecializedTemplate(), Def, nullptr,
4434 VarSpec->getTemplateArgsInfo(), VarSpec->getTemplateArgs().asArray()));
4436 llvm::PointerUnion<VarTemplateDecl *,
4437 VarTemplatePartialSpecializationDecl *> PatternPtr =
4438 VarSpec->getSpecializedTemplateOrPartial();
4439 if (VarTemplatePartialSpecializationDecl *Partial =
4440 PatternPtr.dyn_cast<VarTemplatePartialSpecializationDecl *>())
4441 cast<VarTemplateSpecializationDecl>(Var)->setInstantiationOf(
4442 Partial, &VarSpec->getTemplateInstantiationArgs());
4444 // Merge the definition with the declaration.
4445 LookupResult R(*this, Var->getDeclName(), Var->getLocation(),
4446 LookupOrdinaryName, forRedeclarationInCurContext());
4448 MergeVarDecl(Var, R);
4450 // Attach the initializer.
4451 InstantiateVariableInitializer(Var, Def, TemplateArgs);
4454 // Complete the existing variable's definition with an appropriately
4455 // substituted type and initializer.
4456 Var = CompleteVarTemplateSpecializationDecl(VarSpec, Def, TemplateArgs);
4458 PreviousContext.pop();
4461 PassToConsumerRAII.Var = Var;
4462 Var->setTemplateSpecializationKind(OldVar->getTemplateSpecializationKind(),
4463 OldVar->getPointOfInstantiation());
4466 // This variable may have local implicit instantiations that need to be
4467 // instantiated within this scope.
4468 LocalInstantiations.perform();
4470 GlobalInstantiations.perform();
4474 Sema::InstantiateMemInitializers(CXXConstructorDecl *New,
4475 const CXXConstructorDecl *Tmpl,
4476 const MultiLevelTemplateArgumentList &TemplateArgs) {
4478 SmallVector<CXXCtorInitializer*, 4> NewInits;
4479 bool AnyErrors = Tmpl->isInvalidDecl();
4481 // Instantiate all the initializers.
4482 for (const auto *Init : Tmpl->inits()) {
4483 // Only instantiate written initializers, let Sema re-construct implicit
4485 if (!Init->isWritten())
4488 SourceLocation EllipsisLoc;
4490 if (Init->isPackExpansion()) {
4491 // This is a pack expansion. We should expand it now.
4492 TypeLoc BaseTL = Init->getTypeSourceInfo()->getTypeLoc();
4493 SmallVector<UnexpandedParameterPack, 4> Unexpanded;
4494 collectUnexpandedParameterPacks(BaseTL, Unexpanded);
4495 collectUnexpandedParameterPacks(Init->getInit(), Unexpanded);
4496 bool ShouldExpand = false;
4497 bool RetainExpansion = false;
4498 Optional<unsigned> NumExpansions;
4499 if (CheckParameterPacksForExpansion(Init->getEllipsisLoc(),
4500 BaseTL.getSourceRange(),
4502 TemplateArgs, ShouldExpand,
4506 New->setInvalidDecl();
4509 assert(ShouldExpand && "Partial instantiation of base initializer?");
4511 // Loop over all of the arguments in the argument pack(s),
4512 for (unsigned I = 0; I != *NumExpansions; ++I) {
4513 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, I);
4515 // Instantiate the initializer.
4516 ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs,
4517 /*CXXDirectInit=*/true);
4518 if (TempInit.isInvalid()) {
4523 // Instantiate the base type.
4524 TypeSourceInfo *BaseTInfo = SubstType(Init->getTypeSourceInfo(),
4526 Init->getSourceLocation(),
4527 New->getDeclName());
4533 // Build the initializer.
4534 MemInitResult NewInit = BuildBaseInitializer(BaseTInfo->getType(),
4535 BaseTInfo, TempInit.get(),
4538 if (NewInit.isInvalid()) {
4543 NewInits.push_back(NewInit.get());
4549 // Instantiate the initializer.
4550 ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs,
4551 /*CXXDirectInit=*/true);
4552 if (TempInit.isInvalid()) {
4557 MemInitResult NewInit;
4558 if (Init->isDelegatingInitializer() || Init->isBaseInitializer()) {
4559 TypeSourceInfo *TInfo = SubstType(Init->getTypeSourceInfo(),
4561 Init->getSourceLocation(),
4562 New->getDeclName());
4565 New->setInvalidDecl();
4569 if (Init->isBaseInitializer())
4570 NewInit = BuildBaseInitializer(TInfo->getType(), TInfo, TempInit.get(),
4571 New->getParent(), EllipsisLoc);
4573 NewInit = BuildDelegatingInitializer(TInfo, TempInit.get(),
4574 cast<CXXRecordDecl>(CurContext->getParent()));
4575 } else if (Init->isMemberInitializer()) {
4576 FieldDecl *Member = cast_or_null<FieldDecl>(FindInstantiatedDecl(
4577 Init->getMemberLocation(),
4582 New->setInvalidDecl();
4586 NewInit = BuildMemberInitializer(Member, TempInit.get(),
4587 Init->getSourceLocation());
4588 } else if (Init->isIndirectMemberInitializer()) {
4589 IndirectFieldDecl *IndirectMember =
4590 cast_or_null<IndirectFieldDecl>(FindInstantiatedDecl(
4591 Init->getMemberLocation(),
4592 Init->getIndirectMember(), TemplateArgs));
4594 if (!IndirectMember) {
4596 New->setInvalidDecl();
4600 NewInit = BuildMemberInitializer(IndirectMember, TempInit.get(),
4601 Init->getSourceLocation());
4604 if (NewInit.isInvalid()) {
4606 New->setInvalidDecl();
4608 NewInits.push_back(NewInit.get());
4612 // Assign all the initializers to the new constructor.
4613 ActOnMemInitializers(New,
4614 /*FIXME: ColonLoc */
4620 // TODO: this could be templated if the various decl types used the
4621 // same method name.
4622 static bool isInstantiationOf(ClassTemplateDecl *Pattern,
4623 ClassTemplateDecl *Instance) {
4624 Pattern = Pattern->getCanonicalDecl();
4627 Instance = Instance->getCanonicalDecl();
4628 if (Pattern == Instance) return true;
4629 Instance = Instance->getInstantiatedFromMemberTemplate();
4635 static bool isInstantiationOf(FunctionTemplateDecl *Pattern,
4636 FunctionTemplateDecl *Instance) {
4637 Pattern = Pattern->getCanonicalDecl();
4640 Instance = Instance->getCanonicalDecl();
4641 if (Pattern == Instance) return true;
4642 Instance = Instance->getInstantiatedFromMemberTemplate();
4649 isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern,
4650 ClassTemplatePartialSpecializationDecl *Instance) {
4652 = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
4654 Instance = cast<ClassTemplatePartialSpecializationDecl>(
4655 Instance->getCanonicalDecl());
4656 if (Pattern == Instance)
4658 Instance = Instance->getInstantiatedFromMember();
4664 static bool isInstantiationOf(CXXRecordDecl *Pattern,
4665 CXXRecordDecl *Instance) {
4666 Pattern = Pattern->getCanonicalDecl();
4669 Instance = Instance->getCanonicalDecl();
4670 if (Pattern == Instance) return true;
4671 Instance = Instance->getInstantiatedFromMemberClass();
4677 static bool isInstantiationOf(FunctionDecl *Pattern,
4678 FunctionDecl *Instance) {
4679 Pattern = Pattern->getCanonicalDecl();
4682 Instance = Instance->getCanonicalDecl();
4683 if (Pattern == Instance) return true;
4684 Instance = Instance->getInstantiatedFromMemberFunction();
4690 static bool isInstantiationOf(EnumDecl *Pattern,
4691 EnumDecl *Instance) {
4692 Pattern = Pattern->getCanonicalDecl();
4695 Instance = Instance->getCanonicalDecl();
4696 if (Pattern == Instance) return true;
4697 Instance = Instance->getInstantiatedFromMemberEnum();
4703 static bool isInstantiationOf(UsingShadowDecl *Pattern,
4704 UsingShadowDecl *Instance,
4706 return declaresSameEntity(C.getInstantiatedFromUsingShadowDecl(Instance),
4710 static bool isInstantiationOf(UsingDecl *Pattern, UsingDecl *Instance,
4712 return declaresSameEntity(C.getInstantiatedFromUsingDecl(Instance), Pattern);
4715 template<typename T>
4716 static bool isInstantiationOfUnresolvedUsingDecl(T *Pattern, Decl *Other,
4718 // An unresolved using declaration can instantiate to an unresolved using
4719 // declaration, or to a using declaration or a using declaration pack.
4721 // Multiple declarations can claim to be instantiated from an unresolved
4722 // using declaration if it's a pack expansion. We want the UsingPackDecl
4723 // in that case, not the individual UsingDecls within the pack.
4724 bool OtherIsPackExpansion;
4725 NamedDecl *OtherFrom;
4726 if (auto *OtherUUD = dyn_cast<T>(Other)) {
4727 OtherIsPackExpansion = OtherUUD->isPackExpansion();
4728 OtherFrom = Ctx.getInstantiatedFromUsingDecl(OtherUUD);
4729 } else if (auto *OtherUPD = dyn_cast<UsingPackDecl>(Other)) {
4730 OtherIsPackExpansion = true;
4731 OtherFrom = OtherUPD->getInstantiatedFromUsingDecl();
4732 } else if (auto *OtherUD = dyn_cast<UsingDecl>(Other)) {
4733 OtherIsPackExpansion = false;
4734 OtherFrom = Ctx.getInstantiatedFromUsingDecl(OtherUD);
4738 return Pattern->isPackExpansion() == OtherIsPackExpansion &&
4739 declaresSameEntity(OtherFrom, Pattern);
4742 static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
4743 VarDecl *Instance) {
4744 assert(Instance->isStaticDataMember());
4746 Pattern = Pattern->getCanonicalDecl();
4749 Instance = Instance->getCanonicalDecl();
4750 if (Pattern == Instance) return true;
4751 Instance = Instance->getInstantiatedFromStaticDataMember();
4757 // Other is the prospective instantiation
4758 // D is the prospective pattern
4759 static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
4760 if (auto *UUD = dyn_cast<UnresolvedUsingTypenameDecl>(D))
4761 return isInstantiationOfUnresolvedUsingDecl(UUD, Other, Ctx);
4763 if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(D))
4764 return isInstantiationOfUnresolvedUsingDecl(UUD, Other, Ctx);
4766 if (D->getKind() != Other->getKind())
4769 if (auto *Record = dyn_cast<CXXRecordDecl>(Other))
4770 return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
4772 if (auto *Function = dyn_cast<FunctionDecl>(Other))
4773 return isInstantiationOf(cast<FunctionDecl>(D), Function);
4775 if (auto *Enum = dyn_cast<EnumDecl>(Other))
4776 return isInstantiationOf(cast<EnumDecl>(D), Enum);
4778 if (auto *Var = dyn_cast<VarDecl>(Other))
4779 if (Var->isStaticDataMember())
4780 return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
4782 if (auto *Temp = dyn_cast<ClassTemplateDecl>(Other))
4783 return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
4785 if (auto *Temp = dyn_cast<FunctionTemplateDecl>(Other))
4786 return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
4788 if (auto *PartialSpec =
4789 dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
4790 return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
4793 if (auto *Field = dyn_cast<FieldDecl>(Other)) {
4794 if (!Field->getDeclName()) {
4795 // This is an unnamed field.
4796 return declaresSameEntity(Ctx.getInstantiatedFromUnnamedFieldDecl(Field),
4797 cast<FieldDecl>(D));
4801 if (auto *Using = dyn_cast<UsingDecl>(Other))
4802 return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
4804 if (auto *Shadow = dyn_cast<UsingShadowDecl>(Other))
4805 return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
4807 return D->getDeclName() &&
4808 D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
4811 template<typename ForwardIterator>
4812 static NamedDecl *findInstantiationOf(ASTContext &Ctx,
4814 ForwardIterator first,
4815 ForwardIterator last) {
4816 for (; first != last; ++first)
4817 if (isInstantiationOf(Ctx, D, *first))
4818 return cast<NamedDecl>(*first);
4823 /// \brief Finds the instantiation of the given declaration context
4824 /// within the current instantiation.
4826 /// \returns NULL if there was an error
4827 DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
4828 const MultiLevelTemplateArgumentList &TemplateArgs) {
4829 if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
4830 Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs, true);
4831 return cast_or_null<DeclContext>(ID);
4835 /// \brief Find the instantiation of the given declaration within the
4836 /// current instantiation.
4838 /// This routine is intended to be used when \p D is a declaration
4839 /// referenced from within a template, that needs to mapped into the
4840 /// corresponding declaration within an instantiation. For example,
4844 /// template<typename T>
4847 /// KnownValue = sizeof(T)
4850 /// bool getKind() const { return KnownValue; }
4853 /// template struct X<int>;
4856 /// In the instantiation of <tt>X<int>::getKind()</tt>, we need to map the
4857 /// \p EnumConstantDecl for \p KnownValue (which refers to
4858 /// <tt>X<T>::<Kind>::KnownValue</tt>) to its instantiation
4859 /// (<tt>X<int>::<Kind>::KnownValue</tt>). \p FindInstantiatedDecl performs
4860 /// this mapping from within the instantiation of <tt>X<int></tt>.
4861 NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
4862 const MultiLevelTemplateArgumentList &TemplateArgs,
4863 bool FindingInstantiatedContext) {
4864 DeclContext *ParentDC = D->getDeclContext();
4865 // FIXME: Parmeters of pointer to functions (y below) that are themselves
4866 // parameters (p below) can have their ParentDC set to the translation-unit
4867 // - thus we can not consistently check if the ParentDC of such a parameter
4868 // is Dependent or/and a FunctionOrMethod.
4869 // For e.g. this code, during Template argument deduction tries to
4870 // find an instantiated decl for (T y) when the ParentDC for y is
4871 // the translation unit.
4872 // e.g. template <class T> void Foo(auto (*p)(T y) -> decltype(y())) {}
4873 // float baz(float(*)()) { return 0.0; }
4875 // The better fix here is perhaps to ensure that a ParmVarDecl, by the time
4876 // it gets here, always has a FunctionOrMethod as its ParentDC??
4878 // - as long as we have a ParmVarDecl whose parent is non-dependent and
4879 // whose type is not instantiation dependent, do nothing to the decl
4880 // - otherwise find its instantiated decl.
4881 if (isa<ParmVarDecl>(D) && !ParentDC->isDependentContext() &&
4882 !cast<ParmVarDecl>(D)->getType()->isInstantiationDependentType())
4884 if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
4885 isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
4886 (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext()) ||
4887 (isa<CXXRecordDecl>(D) && cast<CXXRecordDecl>(D)->isLambda())) {
4888 // D is a local of some kind. Look into the map of local
4889 // declarations to their instantiations.
4890 if (CurrentInstantiationScope) {
4891 if (auto Found = CurrentInstantiationScope->findInstantiationOf(D)) {
4892 if (Decl *FD = Found->dyn_cast<Decl *>())
4893 return cast<NamedDecl>(FD);
4895 int PackIdx = ArgumentPackSubstitutionIndex;
4896 assert(PackIdx != -1 &&
4897 "found declaration pack but not pack expanding");
4898 typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack;
4899 return cast<NamedDecl>((*Found->get<DeclArgumentPack *>())[PackIdx]);
4903 // If we're performing a partial substitution during template argument
4904 // deduction, we may not have values for template parameters yet. They
4905 // just map to themselves.
4906 if (isa<NonTypeTemplateParmDecl>(D) || isa<TemplateTypeParmDecl>(D) ||
4907 isa<TemplateTemplateParmDecl>(D))
4910 if (D->isInvalidDecl())
4913 // Normally this function only searches for already instantiated declaration
4914 // however we have to make an exclusion for local types used before
4915 // definition as in the code:
4917 // template<typename T> void f1() {
4918 // void g1(struct x1);
4922 // In this case instantiation of the type of 'g1' requires definition of
4923 // 'x1', which is defined later. Error recovery may produce an enum used
4924 // before definition. In these cases we need to instantiate relevant
4925 // declarations here.
4926 bool NeedInstantiate = false;
4927 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D))
4928 NeedInstantiate = RD->isLocalClass();
4930 NeedInstantiate = isa<EnumDecl>(D);
4931 if (NeedInstantiate) {
4932 Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
4933 CurrentInstantiationScope->InstantiatedLocal(D, Inst);
4934 return cast<TypeDecl>(Inst);
4937 // If we didn't find the decl, then we must have a label decl that hasn't
4938 // been found yet. Lazily instantiate it and return it now.
4939 assert(isa<LabelDecl>(D));
4941 Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
4942 assert(Inst && "Failed to instantiate label??");
4944 CurrentInstantiationScope->InstantiatedLocal(D, Inst);
4945 return cast<LabelDecl>(Inst);
4948 // For variable template specializations, update those that are still
4950 if (VarTemplateSpecializationDecl *VarSpec =
4951 dyn_cast<VarTemplateSpecializationDecl>(D)) {
4952 bool InstantiationDependent = false;
4953 const TemplateArgumentListInfo &VarTemplateArgs =
4954 VarSpec->getTemplateArgsInfo();
4955 if (TemplateSpecializationType::anyDependentTemplateArguments(
4956 VarTemplateArgs, InstantiationDependent))
4957 D = cast<NamedDecl>(
4958 SubstDecl(D, VarSpec->getDeclContext(), TemplateArgs));
4962 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
4963 if (!Record->isDependentContext())
4966 // Determine whether this record is the "templated" declaration describing
4967 // a class template or class template partial specialization.
4968 ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
4970 ClassTemplate = ClassTemplate->getCanonicalDecl();
4971 else if (ClassTemplatePartialSpecializationDecl *PartialSpec
4972 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record))
4973 ClassTemplate = PartialSpec->getSpecializedTemplate()->getCanonicalDecl();
4975 // Walk the current context to find either the record or an instantiation of
4977 DeclContext *DC = CurContext;
4978 while (!DC->isFileContext()) {
4979 // If we're performing substitution while we're inside the template
4980 // definition, we'll find our own context. We're done.
4981 if (DC->Equals(Record))
4984 if (CXXRecordDecl *InstRecord = dyn_cast<CXXRecordDecl>(DC)) {
4985 // Check whether we're in the process of instantiating a class template
4986 // specialization of the template we're mapping.
4987 if (ClassTemplateSpecializationDecl *InstSpec
4988 = dyn_cast<ClassTemplateSpecializationDecl>(InstRecord)){
4989 ClassTemplateDecl *SpecTemplate = InstSpec->getSpecializedTemplate();
4990 if (ClassTemplate && isInstantiationOf(ClassTemplate, SpecTemplate))
4994 // Check whether we're in the process of instantiating a member class.
4995 if (isInstantiationOf(Record, InstRecord))
4999 // Move to the outer template scope.
5000 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) {
5001 if (FD->getFriendObjectKind() && FD->getDeclContext()->isFileContext()){
5002 DC = FD->getLexicalDeclContext();
5005 // An implicit deduction guide acts as if it's within the class template
5006 // specialization described by its name and first N template params.
5007 auto *Guide = dyn_cast<CXXDeductionGuideDecl>(FD);
5008 if (Guide && Guide->isImplicit()) {
5009 TemplateDecl *TD = Guide->getDeducedTemplate();
5010 // Convert the arguments to an "as-written" list.
5011 TemplateArgumentListInfo Args(Loc, Loc);
5012 for (TemplateArgument Arg : TemplateArgs.getInnermost().take_front(
5013 TD->getTemplateParameters()->size())) {
5014 ArrayRef<TemplateArgument> Unpacked(Arg);
5015 if (Arg.getKind() == TemplateArgument::Pack)
5016 Unpacked = Arg.pack_elements();
5017 for (TemplateArgument UnpackedArg : Unpacked)
5019 getTrivialTemplateArgumentLoc(UnpackedArg, QualType(), Loc));
5021 QualType T = CheckTemplateIdType(TemplateName(TD), Loc, Args);
5024 auto *SubstRecord = T->getAsCXXRecordDecl();
5025 assert(SubstRecord && "class template id not a class type?");
5026 // Check that this template-id names the primary template and not a
5027 // partial or explicit specialization. (In the latter cases, it's
5028 // meaningless to attempt to find an instantiation of D within the
5030 // FIXME: The standard doesn't say what should happen here.
5031 if (FindingInstantiatedContext &&
5032 usesPartialOrExplicitSpecialization(
5033 Loc, cast<ClassTemplateSpecializationDecl>(SubstRecord))) {
5034 Diag(Loc, diag::err_specialization_not_primary_template)
5035 << T << (SubstRecord->getTemplateSpecializationKind() ==
5036 TSK_ExplicitSpecialization);
5044 DC = DC->getParent();
5047 // Fall through to deal with other dependent record types (e.g.,
5048 // anonymous unions in class templates).
5051 if (!ParentDC->isDependentContext())
5054 ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
5058 if (ParentDC != D->getDeclContext()) {
5059 // We performed some kind of instantiation in the parent context,
5060 // so now we need to look into the instantiated parent context to
5061 // find the instantiation of the declaration D.
5063 // If our context used to be dependent, we may need to instantiate
5064 // it before performing lookup into that context.
5065 bool IsBeingInstantiated = false;
5066 if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
5067 if (!Spec->isDependentContext()) {
5068 QualType T = Context.getTypeDeclType(Spec);
5069 const RecordType *Tag = T->getAs<RecordType>();
5070 assert(Tag && "type of non-dependent record is not a RecordType");
5071 if (Tag->isBeingDefined())
5072 IsBeingInstantiated = true;
5073 if (!Tag->isBeingDefined() &&
5074 RequireCompleteType(Loc, T, diag::err_incomplete_type))
5077 ParentDC = Tag->getDecl();
5081 NamedDecl *Result = nullptr;
5082 // FIXME: If the name is a dependent name, this lookup won't necessarily
5083 // find it. Does that ever matter?
5084 if (auto Name = D->getDeclName()) {
5085 DeclarationNameInfo NameInfo(Name, D->getLocation());
5086 Name = SubstDeclarationNameInfo(NameInfo, TemplateArgs).getName();
5089 DeclContext::lookup_result Found = ParentDC->lookup(Name);
5090 Result = findInstantiationOf(Context, D, Found.begin(), Found.end());
5092 // Since we don't have a name for the entity we're looking for,
5093 // our only option is to walk through all of the declarations to
5094 // find that name. This will occur in a few cases:
5096 // - anonymous struct/union within a template
5097 // - unnamed class/struct/union/enum within a template
5099 // FIXME: Find a better way to find these instantiations!
5100 Result = findInstantiationOf(Context, D,
5101 ParentDC->decls_begin(),
5102 ParentDC->decls_end());
5106 if (isa<UsingShadowDecl>(D)) {
5107 // UsingShadowDecls can instantiate to nothing because of using hiding.
5108 } else if (Diags.hasErrorOccurred()) {
5109 // We've already complained about something, so most likely this
5110 // declaration failed to instantiate. There's no point in complaining
5111 // further, since this is normal in invalid code.
5112 } else if (IsBeingInstantiated) {
5113 // The class in which this member exists is currently being
5114 // instantiated, and we haven't gotten around to instantiating this
5115 // member yet. This can happen when the code uses forward declarations
5116 // of member classes, and introduces ordering dependencies via
5117 // template instantiation.
5118 Diag(Loc, diag::err_member_not_yet_instantiated)
5120 << Context.getTypeDeclType(cast<CXXRecordDecl>(ParentDC));
5121 Diag(D->getLocation(), diag::note_non_instantiated_member_here);
5122 } else if (EnumConstantDecl *ED = dyn_cast<EnumConstantDecl>(D)) {
5123 // This enumeration constant was found when the template was defined,
5124 // but can't be found in the instantiation. This can happen if an
5125 // unscoped enumeration member is explicitly specialized.
5126 EnumDecl *Enum = cast<EnumDecl>(ED->getLexicalDeclContext());
5127 EnumDecl *Spec = cast<EnumDecl>(FindInstantiatedDecl(Loc, Enum,
5129 assert(Spec->getTemplateSpecializationKind() ==
5130 TSK_ExplicitSpecialization);
5131 Diag(Loc, diag::err_enumerator_does_not_exist)
5133 << Context.getTypeDeclType(cast<TypeDecl>(Spec->getDeclContext()));
5134 Diag(Spec->getLocation(), diag::note_enum_specialized_here)
5135 << Context.getTypeDeclType(Spec);
5137 // We should have found something, but didn't.
5138 llvm_unreachable("Unable to find instantiation of declaration!");
5148 /// \brief Performs template instantiation for all implicit template
5149 /// instantiations we have seen until this point.
5150 void Sema::PerformPendingInstantiations(bool LocalOnly) {
5151 while (!PendingLocalImplicitInstantiations.empty() ||
5152 (!LocalOnly && !PendingInstantiations.empty())) {
5153 PendingImplicitInstantiation Inst;
5155 if (PendingLocalImplicitInstantiations.empty()) {
5156 Inst = PendingInstantiations.front();
5157 PendingInstantiations.pop_front();
5159 Inst = PendingLocalImplicitInstantiations.front();
5160 PendingLocalImplicitInstantiations.pop_front();
5163 // Instantiate function definitions
5164 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
5165 bool DefinitionRequired = Function->getTemplateSpecializationKind() ==
5166 TSK_ExplicitInstantiationDefinition;
5167 InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true,
5168 DefinitionRequired, true);
5169 if (Function->isDefined())
5170 Function->setInstantiationIsPending(false);
5174 // Instantiate variable definitions
5175 VarDecl *Var = cast<VarDecl>(Inst.first);
5177 assert((Var->isStaticDataMember() ||
5178 isa<VarTemplateSpecializationDecl>(Var)) &&
5179 "Not a static data member, nor a variable template"
5180 " specialization?");
5182 // Don't try to instantiate declarations if the most recent redeclaration
5184 if (Var->getMostRecentDecl()->isInvalidDecl())
5187 // Check if the most recent declaration has changed the specialization kind
5188 // and removed the need for implicit instantiation.
5189 switch (Var->getMostRecentDecl()->getTemplateSpecializationKind()) {
5190 case TSK_Undeclared:
5191 llvm_unreachable("Cannot instantitiate an undeclared specialization.");
5192 case TSK_ExplicitInstantiationDeclaration:
5193 case TSK_ExplicitSpecialization:
5194 continue; // No longer need to instantiate this type.
5195 case TSK_ExplicitInstantiationDefinition:
5196 // We only need an instantiation if the pending instantiation *is* the
5197 // explicit instantiation.
5198 if (Var != Var->getMostRecentDecl()) continue;
5199 case TSK_ImplicitInstantiation:
5203 PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
5204 "instantiating variable definition");
5205 bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
5206 TSK_ExplicitInstantiationDefinition;
5208 // Instantiate static data member definitions or variable template
5210 InstantiateVariableDefinition(/*FIXME:*/ Inst.second, Var, true,
5211 DefinitionRequired, true);
5215 void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,
5216 const MultiLevelTemplateArgumentList &TemplateArgs) {
5217 for (auto DD : Pattern->ddiags()) {
5218 switch (DD->getKind()) {
5219 case DependentDiagnostic::Access:
5220 HandleDependentAccessCheck(*DD, TemplateArgs);