1 //===------- SemaTemplateInstantiate.cpp - C++ Template 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.
11 //===----------------------------------------------------------------------===/
13 #include "clang/Sema/SemaInternal.h"
14 #include "TreeTransform.h"
15 #include "clang/AST/ASTConsumer.h"
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/ASTLambda.h"
18 #include "clang/AST/ASTMutationListener.h"
19 #include "clang/AST/DeclTemplate.h"
20 #include "clang/AST/Expr.h"
21 #include "clang/AST/PrettyDeclStackTrace.h"
22 #include "clang/Basic/LangOptions.h"
23 #include "clang/Sema/DeclSpec.h"
24 #include "clang/Sema/Initialization.h"
25 #include "clang/Sema/Lookup.h"
26 #include "clang/Sema/Template.h"
27 #include "clang/Sema/TemplateDeduction.h"
28 #include "clang/Sema/TemplateInstCallback.h"
30 using namespace clang;
33 //===----------------------------------------------------------------------===/
34 // Template Instantiation Support
35 //===----------------------------------------------------------------------===/
37 /// Retrieve the template argument list(s) that should be used to
38 /// instantiate the definition of the given declaration.
40 /// \param D the declaration for which we are computing template instantiation
43 /// \param Innermost if non-NULL, the innermost template argument list.
45 /// \param RelativeToPrimary true if we should get the template
46 /// arguments relative to the primary template, even when we're
47 /// dealing with a specialization. This is only relevant for function
48 /// template specializations.
50 /// \param Pattern If non-NULL, indicates the pattern from which we will be
51 /// instantiating the definition of the given declaration, \p D. This is
52 /// used to determine the proper set of template instantiation arguments for
53 /// friend function template specializations.
54 MultiLevelTemplateArgumentList
55 Sema::getTemplateInstantiationArgs(NamedDecl *D,
56 const TemplateArgumentList *Innermost,
57 bool RelativeToPrimary,
58 const FunctionDecl *Pattern) {
59 // Accumulate the set of template argument lists in this structure.
60 MultiLevelTemplateArgumentList Result;
63 Result.addOuterTemplateArguments(Innermost);
65 DeclContext *Ctx = dyn_cast<DeclContext>(D);
67 Ctx = D->getDeclContext();
69 // Add template arguments from a variable template instantiation.
70 if (VarTemplateSpecializationDecl *Spec =
71 dyn_cast<VarTemplateSpecializationDecl>(D)) {
72 // We're done when we hit an explicit specialization.
73 if (Spec->getSpecializationKind() == TSK_ExplicitSpecialization &&
74 !isa<VarTemplatePartialSpecializationDecl>(Spec))
77 Result.addOuterTemplateArguments(&Spec->getTemplateInstantiationArgs());
79 // If this variable template specialization was instantiated from a
80 // specialized member that is a variable template, we're done.
81 assert(Spec->getSpecializedTemplate() && "No variable template?");
82 llvm::PointerUnion<VarTemplateDecl*,
83 VarTemplatePartialSpecializationDecl*> Specialized
84 = Spec->getSpecializedTemplateOrPartial();
85 if (VarTemplatePartialSpecializationDecl *Partial =
86 Specialized.dyn_cast<VarTemplatePartialSpecializationDecl *>()) {
87 if (Partial->isMemberSpecialization())
90 VarTemplateDecl *Tmpl = Specialized.get<VarTemplateDecl *>();
91 if (Tmpl->isMemberSpecialization())
96 // If we have a template template parameter with translation unit context,
97 // then we're performing substitution into a default template argument of
98 // this template template parameter before we've constructed the template
99 // that will own this template template parameter. In this case, we
100 // use empty template parameter lists for all of the outer templates
101 // to avoid performing any substitutions.
102 if (Ctx->isTranslationUnit()) {
103 if (TemplateTemplateParmDecl *TTP
104 = dyn_cast<TemplateTemplateParmDecl>(D)) {
105 for (unsigned I = 0, N = TTP->getDepth() + 1; I != N; ++I)
106 Result.addOuterTemplateArguments(None);
112 while (!Ctx->isFileContext()) {
113 // Add template arguments from a class template instantiation.
114 if (ClassTemplateSpecializationDecl *Spec
115 = dyn_cast<ClassTemplateSpecializationDecl>(Ctx)) {
116 // We're done when we hit an explicit specialization.
117 if (Spec->getSpecializationKind() == TSK_ExplicitSpecialization &&
118 !isa<ClassTemplatePartialSpecializationDecl>(Spec))
121 Result.addOuterTemplateArguments(&Spec->getTemplateInstantiationArgs());
123 // If this class template specialization was instantiated from a
124 // specialized member that is a class template, we're done.
125 assert(Spec->getSpecializedTemplate() && "No class template?");
126 if (Spec->getSpecializedTemplate()->isMemberSpecialization())
129 // Add template arguments from a function template specialization.
130 else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Ctx)) {
131 if (!RelativeToPrimary &&
132 (Function->getTemplateSpecializationKind() ==
133 TSK_ExplicitSpecialization &&
134 !Function->getClassScopeSpecializationPattern()))
137 if (const TemplateArgumentList *TemplateArgs
138 = Function->getTemplateSpecializationArgs()) {
139 // Add the template arguments for this specialization.
140 Result.addOuterTemplateArguments(TemplateArgs);
142 // If this function was instantiated from a specialized member that is
143 // a function template, we're done.
144 assert(Function->getPrimaryTemplate() && "No function template?");
145 if (Function->getPrimaryTemplate()->isMemberSpecialization())
148 // If this function is a generic lambda specialization, we are done.
149 if (isGenericLambdaCallOperatorSpecialization(Function))
152 } else if (FunctionTemplateDecl *FunTmpl
153 = Function->getDescribedFunctionTemplate()) {
154 // Add the "injected" template arguments.
155 Result.addOuterTemplateArguments(FunTmpl->getInjectedTemplateArgs());
158 // If this is a friend declaration and it declares an entity at
159 // namespace scope, take arguments from its lexical parent
160 // instead of its semantic parent, unless of course the pattern we're
161 // instantiating actually comes from the file's context!
162 if (Function->getFriendObjectKind() &&
163 Function->getDeclContext()->isFileContext() &&
164 (!Pattern || !Pattern->getLexicalDeclContext()->isFileContext())) {
165 Ctx = Function->getLexicalDeclContext();
166 RelativeToPrimary = false;
169 } else if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Ctx)) {
170 if (ClassTemplateDecl *ClassTemplate = Rec->getDescribedClassTemplate()) {
171 QualType T = ClassTemplate->getInjectedClassNameSpecialization();
172 const TemplateSpecializationType *TST =
173 cast<TemplateSpecializationType>(Context.getCanonicalType(T));
174 Result.addOuterTemplateArguments(
175 llvm::makeArrayRef(TST->getArgs(), TST->getNumArgs()));
176 if (ClassTemplate->isMemberSpecialization())
181 Ctx = Ctx->getParent();
182 RelativeToPrimary = false;
188 bool Sema::CodeSynthesisContext::isInstantiationRecord() const {
190 case TemplateInstantiation:
191 case ExceptionSpecInstantiation:
192 case DefaultTemplateArgumentInstantiation:
193 case DefaultFunctionArgumentInstantiation:
194 case ExplicitTemplateArgumentSubstitution:
195 case DeducedTemplateArgumentSubstitution:
196 case PriorTemplateArgumentSubstitution:
199 case DefaultTemplateArgumentChecking:
200 case DeclaringSpecialMember:
201 case DefiningSynthesizedFunction:
204 // This function should never be called when Kind's value is Memoization.
209 llvm_unreachable("Invalid SynthesisKind!");
212 Sema::InstantiatingTemplate::InstantiatingTemplate(
213 Sema &SemaRef, CodeSynthesisContext::SynthesisKind Kind,
214 SourceLocation PointOfInstantiation, SourceRange InstantiationRange,
215 Decl *Entity, NamedDecl *Template, ArrayRef<TemplateArgument> TemplateArgs,
216 sema::TemplateDeductionInfo *DeductionInfo)
218 // Don't allow further instantiation if a fatal error and an uncompilable
219 // error have occurred. Any diagnostics we might have raised will not be
220 // visible, and we do not need to construct a correct AST.
221 if (SemaRef.Diags.hasFatalErrorOccurred() &&
222 SemaRef.Diags.hasUncompilableErrorOccurred()) {
226 Invalid = CheckInstantiationDepth(PointOfInstantiation, InstantiationRange);
228 CodeSynthesisContext Inst;
230 Inst.PointOfInstantiation = PointOfInstantiation;
231 Inst.Entity = Entity;
232 Inst.Template = Template;
233 Inst.TemplateArgs = TemplateArgs.data();
234 Inst.NumTemplateArgs = TemplateArgs.size();
235 Inst.DeductionInfo = DeductionInfo;
236 Inst.InstantiationRange = InstantiationRange;
237 SemaRef.pushCodeSynthesisContext(Inst);
239 AlreadyInstantiating =
240 !SemaRef.InstantiatingSpecializations
241 .insert(std::make_pair(Inst.Entity->getCanonicalDecl(), Inst.Kind))
243 atTemplateBegin(SemaRef.TemplateInstCallbacks, SemaRef, Inst);
247 Sema::InstantiatingTemplate::InstantiatingTemplate(
248 Sema &SemaRef, SourceLocation PointOfInstantiation, Decl *Entity,
249 SourceRange InstantiationRange)
250 : InstantiatingTemplate(SemaRef,
251 CodeSynthesisContext::TemplateInstantiation,
252 PointOfInstantiation, InstantiationRange, Entity) {}
254 Sema::InstantiatingTemplate::InstantiatingTemplate(
255 Sema &SemaRef, SourceLocation PointOfInstantiation, FunctionDecl *Entity,
256 ExceptionSpecification, SourceRange InstantiationRange)
257 : InstantiatingTemplate(
258 SemaRef, CodeSynthesisContext::ExceptionSpecInstantiation,
259 PointOfInstantiation, InstantiationRange, Entity) {}
261 Sema::InstantiatingTemplate::InstantiatingTemplate(
262 Sema &SemaRef, SourceLocation PointOfInstantiation, TemplateParameter Param,
263 TemplateDecl *Template, ArrayRef<TemplateArgument> TemplateArgs,
264 SourceRange InstantiationRange)
265 : InstantiatingTemplate(
267 CodeSynthesisContext::DefaultTemplateArgumentInstantiation,
268 PointOfInstantiation, InstantiationRange, getAsNamedDecl(Param),
269 Template, TemplateArgs) {}
271 Sema::InstantiatingTemplate::InstantiatingTemplate(
272 Sema &SemaRef, SourceLocation PointOfInstantiation,
273 FunctionTemplateDecl *FunctionTemplate,
274 ArrayRef<TemplateArgument> TemplateArgs,
275 CodeSynthesisContext::SynthesisKind Kind,
276 sema::TemplateDeductionInfo &DeductionInfo, SourceRange InstantiationRange)
277 : InstantiatingTemplate(SemaRef, Kind, PointOfInstantiation,
278 InstantiationRange, FunctionTemplate, nullptr,
279 TemplateArgs, &DeductionInfo) {
281 Kind == CodeSynthesisContext::ExplicitTemplateArgumentSubstitution ||
282 Kind == CodeSynthesisContext::DeducedTemplateArgumentSubstitution);
285 Sema::InstantiatingTemplate::InstantiatingTemplate(
286 Sema &SemaRef, SourceLocation PointOfInstantiation,
287 TemplateDecl *Template,
288 ArrayRef<TemplateArgument> TemplateArgs,
289 sema::TemplateDeductionInfo &DeductionInfo, SourceRange InstantiationRange)
290 : InstantiatingTemplate(
292 CodeSynthesisContext::DeducedTemplateArgumentSubstitution,
293 PointOfInstantiation, InstantiationRange, Template, nullptr,
294 TemplateArgs, &DeductionInfo) {}
296 Sema::InstantiatingTemplate::InstantiatingTemplate(
297 Sema &SemaRef, SourceLocation PointOfInstantiation,
298 ClassTemplatePartialSpecializationDecl *PartialSpec,
299 ArrayRef<TemplateArgument> TemplateArgs,
300 sema::TemplateDeductionInfo &DeductionInfo, SourceRange InstantiationRange)
301 : InstantiatingTemplate(
303 CodeSynthesisContext::DeducedTemplateArgumentSubstitution,
304 PointOfInstantiation, InstantiationRange, PartialSpec, nullptr,
305 TemplateArgs, &DeductionInfo) {}
307 Sema::InstantiatingTemplate::InstantiatingTemplate(
308 Sema &SemaRef, SourceLocation PointOfInstantiation,
309 VarTemplatePartialSpecializationDecl *PartialSpec,
310 ArrayRef<TemplateArgument> TemplateArgs,
311 sema::TemplateDeductionInfo &DeductionInfo, SourceRange InstantiationRange)
312 : InstantiatingTemplate(
314 CodeSynthesisContext::DeducedTemplateArgumentSubstitution,
315 PointOfInstantiation, InstantiationRange, PartialSpec, nullptr,
316 TemplateArgs, &DeductionInfo) {}
318 Sema::InstantiatingTemplate::InstantiatingTemplate(
319 Sema &SemaRef, SourceLocation PointOfInstantiation, ParmVarDecl *Param,
320 ArrayRef<TemplateArgument> TemplateArgs, SourceRange InstantiationRange)
321 : InstantiatingTemplate(
323 CodeSynthesisContext::DefaultFunctionArgumentInstantiation,
324 PointOfInstantiation, InstantiationRange, Param, nullptr,
327 Sema::InstantiatingTemplate::InstantiatingTemplate(
328 Sema &SemaRef, SourceLocation PointOfInstantiation, NamedDecl *Template,
329 NonTypeTemplateParmDecl *Param, ArrayRef<TemplateArgument> TemplateArgs,
330 SourceRange InstantiationRange)
331 : InstantiatingTemplate(
333 CodeSynthesisContext::PriorTemplateArgumentSubstitution,
334 PointOfInstantiation, InstantiationRange, Param, Template,
337 Sema::InstantiatingTemplate::InstantiatingTemplate(
338 Sema &SemaRef, SourceLocation PointOfInstantiation, NamedDecl *Template,
339 TemplateTemplateParmDecl *Param, ArrayRef<TemplateArgument> TemplateArgs,
340 SourceRange InstantiationRange)
341 : InstantiatingTemplate(
343 CodeSynthesisContext::PriorTemplateArgumentSubstitution,
344 PointOfInstantiation, InstantiationRange, Param, Template,
347 Sema::InstantiatingTemplate::InstantiatingTemplate(
348 Sema &SemaRef, SourceLocation PointOfInstantiation, TemplateDecl *Template,
349 NamedDecl *Param, ArrayRef<TemplateArgument> TemplateArgs,
350 SourceRange InstantiationRange)
351 : InstantiatingTemplate(
352 SemaRef, CodeSynthesisContext::DefaultTemplateArgumentChecking,
353 PointOfInstantiation, InstantiationRange, Param, Template,
356 void Sema::pushCodeSynthesisContext(CodeSynthesisContext Ctx) {
357 Ctx.SavedInNonInstantiationSFINAEContext = InNonInstantiationSFINAEContext;
358 InNonInstantiationSFINAEContext = false;
360 CodeSynthesisContexts.push_back(Ctx);
362 if (!Ctx.isInstantiationRecord())
363 ++NonInstantiationEntries;
366 void Sema::popCodeSynthesisContext() {
367 auto &Active = CodeSynthesisContexts.back();
368 if (!Active.isInstantiationRecord()) {
369 assert(NonInstantiationEntries > 0);
370 --NonInstantiationEntries;
373 InNonInstantiationSFINAEContext = Active.SavedInNonInstantiationSFINAEContext;
375 // Name lookup no longer looks in this template's defining module.
376 assert(CodeSynthesisContexts.size() >=
377 CodeSynthesisContextLookupModules.size() &&
378 "forgot to remove a lookup module for a template instantiation");
379 if (CodeSynthesisContexts.size() ==
380 CodeSynthesisContextLookupModules.size()) {
381 if (Module *M = CodeSynthesisContextLookupModules.back())
382 LookupModulesCache.erase(M);
383 CodeSynthesisContextLookupModules.pop_back();
386 // If we've left the code synthesis context for the current context stack,
387 // stop remembering that we've emitted that stack.
388 if (CodeSynthesisContexts.size() ==
389 LastEmittedCodeSynthesisContextDepth)
390 LastEmittedCodeSynthesisContextDepth = 0;
392 CodeSynthesisContexts.pop_back();
395 void Sema::InstantiatingTemplate::Clear() {
397 if (!AlreadyInstantiating) {
398 auto &Active = SemaRef.CodeSynthesisContexts.back();
399 SemaRef.InstantiatingSpecializations.erase(
400 std::make_pair(Active.Entity, Active.Kind));
403 atTemplateEnd(SemaRef.TemplateInstCallbacks, SemaRef,
404 SemaRef.CodeSynthesisContexts.back());
406 SemaRef.popCodeSynthesisContext();
411 bool Sema::InstantiatingTemplate::CheckInstantiationDepth(
412 SourceLocation PointOfInstantiation,
413 SourceRange InstantiationRange) {
414 assert(SemaRef.NonInstantiationEntries <=
415 SemaRef.CodeSynthesisContexts.size());
416 if ((SemaRef.CodeSynthesisContexts.size() -
417 SemaRef.NonInstantiationEntries)
418 <= SemaRef.getLangOpts().InstantiationDepth)
421 SemaRef.Diag(PointOfInstantiation,
422 diag::err_template_recursion_depth_exceeded)
423 << SemaRef.getLangOpts().InstantiationDepth
424 << InstantiationRange;
425 SemaRef.Diag(PointOfInstantiation, diag::note_template_recursion_depth)
426 << SemaRef.getLangOpts().InstantiationDepth;
430 /// Prints the current instantiation stack through a series of
432 void Sema::PrintInstantiationStack() {
433 // Determine which template instantiations to skip, if any.
434 unsigned SkipStart = CodeSynthesisContexts.size(), SkipEnd = SkipStart;
435 unsigned Limit = Diags.getTemplateBacktraceLimit();
436 if (Limit && Limit < CodeSynthesisContexts.size()) {
437 SkipStart = Limit / 2 + Limit % 2;
438 SkipEnd = CodeSynthesisContexts.size() - Limit / 2;
441 // FIXME: In all of these cases, we need to show the template arguments
442 unsigned InstantiationIdx = 0;
443 for (SmallVectorImpl<CodeSynthesisContext>::reverse_iterator
444 Active = CodeSynthesisContexts.rbegin(),
445 ActiveEnd = CodeSynthesisContexts.rend();
447 ++Active, ++InstantiationIdx) {
448 // Skip this instantiation?
449 if (InstantiationIdx >= SkipStart && InstantiationIdx < SkipEnd) {
450 if (InstantiationIdx == SkipStart) {
451 // Note that we're skipping instantiations.
452 Diags.Report(Active->PointOfInstantiation,
453 diag::note_instantiation_contexts_suppressed)
454 << unsigned(CodeSynthesisContexts.size() - Limit);
459 switch (Active->Kind) {
460 case CodeSynthesisContext::TemplateInstantiation: {
461 Decl *D = Active->Entity;
462 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
463 unsigned DiagID = diag::note_template_member_class_here;
464 if (isa<ClassTemplateSpecializationDecl>(Record))
465 DiagID = diag::note_template_class_instantiation_here;
466 Diags.Report(Active->PointOfInstantiation, DiagID)
467 << Record << Active->InstantiationRange;
468 } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) {
470 if (Function->getPrimaryTemplate())
471 DiagID = diag::note_function_template_spec_here;
473 DiagID = diag::note_template_member_function_here;
474 Diags.Report(Active->PointOfInstantiation, DiagID)
476 << Active->InstantiationRange;
477 } else if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
478 Diags.Report(Active->PointOfInstantiation,
479 VD->isStaticDataMember()?
480 diag::note_template_static_data_member_def_here
481 : diag::note_template_variable_def_here)
483 << Active->InstantiationRange;
484 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(D)) {
485 Diags.Report(Active->PointOfInstantiation,
486 diag::note_template_enum_def_here)
488 << Active->InstantiationRange;
489 } else if (FieldDecl *FD = dyn_cast<FieldDecl>(D)) {
490 Diags.Report(Active->PointOfInstantiation,
491 diag::note_template_nsdmi_here)
492 << FD << Active->InstantiationRange;
494 Diags.Report(Active->PointOfInstantiation,
495 diag::note_template_type_alias_instantiation_here)
496 << cast<TypeAliasTemplateDecl>(D)
497 << Active->InstantiationRange;
502 case CodeSynthesisContext::DefaultTemplateArgumentInstantiation: {
503 TemplateDecl *Template = cast<TemplateDecl>(Active->Template);
504 SmallVector<char, 128> TemplateArgsStr;
505 llvm::raw_svector_ostream OS(TemplateArgsStr);
506 Template->printName(OS);
507 printTemplateArgumentList(OS, Active->template_arguments(),
508 getPrintingPolicy());
509 Diags.Report(Active->PointOfInstantiation,
510 diag::note_default_arg_instantiation_here)
512 << Active->InstantiationRange;
516 case CodeSynthesisContext::ExplicitTemplateArgumentSubstitution: {
517 FunctionTemplateDecl *FnTmpl = cast<FunctionTemplateDecl>(Active->Entity);
518 Diags.Report(Active->PointOfInstantiation,
519 diag::note_explicit_template_arg_substitution_here)
521 << getTemplateArgumentBindingsText(FnTmpl->getTemplateParameters(),
522 Active->TemplateArgs,
523 Active->NumTemplateArgs)
524 << Active->InstantiationRange;
528 case CodeSynthesisContext::DeducedTemplateArgumentSubstitution: {
529 if (FunctionTemplateDecl *FnTmpl =
530 dyn_cast<FunctionTemplateDecl>(Active->Entity)) {
531 Diags.Report(Active->PointOfInstantiation,
532 diag::note_function_template_deduction_instantiation_here)
534 << getTemplateArgumentBindingsText(FnTmpl->getTemplateParameters(),
535 Active->TemplateArgs,
536 Active->NumTemplateArgs)
537 << Active->InstantiationRange;
539 bool IsVar = isa<VarTemplateDecl>(Active->Entity) ||
540 isa<VarTemplateSpecializationDecl>(Active->Entity);
541 bool IsTemplate = false;
542 TemplateParameterList *Params;
543 if (auto *D = dyn_cast<TemplateDecl>(Active->Entity)) {
545 Params = D->getTemplateParameters();
546 } else if (auto *D = dyn_cast<ClassTemplatePartialSpecializationDecl>(
548 Params = D->getTemplateParameters();
549 } else if (auto *D = dyn_cast<VarTemplatePartialSpecializationDecl>(
551 Params = D->getTemplateParameters();
553 llvm_unreachable("unexpected template kind");
556 Diags.Report(Active->PointOfInstantiation,
557 diag::note_deduced_template_arg_substitution_here)
558 << IsVar << IsTemplate << cast<NamedDecl>(Active->Entity)
559 << getTemplateArgumentBindingsText(Params, Active->TemplateArgs,
560 Active->NumTemplateArgs)
561 << Active->InstantiationRange;
566 case CodeSynthesisContext::DefaultFunctionArgumentInstantiation: {
567 ParmVarDecl *Param = cast<ParmVarDecl>(Active->Entity);
568 FunctionDecl *FD = cast<FunctionDecl>(Param->getDeclContext());
570 SmallVector<char, 128> TemplateArgsStr;
571 llvm::raw_svector_ostream OS(TemplateArgsStr);
573 printTemplateArgumentList(OS, Active->template_arguments(),
574 getPrintingPolicy());
575 Diags.Report(Active->PointOfInstantiation,
576 diag::note_default_function_arg_instantiation_here)
578 << Active->InstantiationRange;
582 case CodeSynthesisContext::PriorTemplateArgumentSubstitution: {
583 NamedDecl *Parm = cast<NamedDecl>(Active->Entity);
585 if (!Parm->getName().empty())
586 Name = std::string(" '") + Parm->getName().str() + "'";
588 TemplateParameterList *TemplateParams = nullptr;
589 if (TemplateDecl *Template = dyn_cast<TemplateDecl>(Active->Template))
590 TemplateParams = Template->getTemplateParameters();
593 cast<ClassTemplatePartialSpecializationDecl>(Active->Template)
594 ->getTemplateParameters();
595 Diags.Report(Active->PointOfInstantiation,
596 diag::note_prior_template_arg_substitution)
597 << isa<TemplateTemplateParmDecl>(Parm)
599 << getTemplateArgumentBindingsText(TemplateParams,
600 Active->TemplateArgs,
601 Active->NumTemplateArgs)
602 << Active->InstantiationRange;
606 case CodeSynthesisContext::DefaultTemplateArgumentChecking: {
607 TemplateParameterList *TemplateParams = nullptr;
608 if (TemplateDecl *Template = dyn_cast<TemplateDecl>(Active->Template))
609 TemplateParams = Template->getTemplateParameters();
612 cast<ClassTemplatePartialSpecializationDecl>(Active->Template)
613 ->getTemplateParameters();
615 Diags.Report(Active->PointOfInstantiation,
616 diag::note_template_default_arg_checking)
617 << getTemplateArgumentBindingsText(TemplateParams,
618 Active->TemplateArgs,
619 Active->NumTemplateArgs)
620 << Active->InstantiationRange;
624 case CodeSynthesisContext::ExceptionSpecInstantiation:
625 Diags.Report(Active->PointOfInstantiation,
626 diag::note_template_exception_spec_instantiation_here)
627 << cast<FunctionDecl>(Active->Entity)
628 << Active->InstantiationRange;
631 case CodeSynthesisContext::DeclaringSpecialMember:
632 Diags.Report(Active->PointOfInstantiation,
633 diag::note_in_declaration_of_implicit_special_member)
634 << cast<CXXRecordDecl>(Active->Entity) << Active->SpecialMember;
637 case CodeSynthesisContext::DefiningSynthesizedFunction: {
638 // FIXME: For synthesized members other than special members, produce a note.
639 auto *MD = dyn_cast<CXXMethodDecl>(Active->Entity);
640 auto CSM = MD ? getSpecialMember(MD) : CXXInvalid;
641 if (CSM != CXXInvalid) {
642 Diags.Report(Active->PointOfInstantiation,
643 diag::note_member_synthesized_at)
644 << CSM << Context.getTagDeclType(MD->getParent());
649 case CodeSynthesisContext::Memoization:
655 Optional<TemplateDeductionInfo *> Sema::isSFINAEContext() const {
656 if (InNonInstantiationSFINAEContext)
657 return Optional<TemplateDeductionInfo *>(nullptr);
659 for (SmallVectorImpl<CodeSynthesisContext>::const_reverse_iterator
660 Active = CodeSynthesisContexts.rbegin(),
661 ActiveEnd = CodeSynthesisContexts.rend();
665 switch (Active->Kind) {
666 case CodeSynthesisContext::TemplateInstantiation:
667 // An instantiation of an alias template may or may not be a SFINAE
668 // context, depending on what else is on the stack.
669 if (isa<TypeAliasTemplateDecl>(Active->Entity))
672 case CodeSynthesisContext::DefaultFunctionArgumentInstantiation:
673 case CodeSynthesisContext::ExceptionSpecInstantiation:
674 // This is a template instantiation, so there is no SFINAE.
677 case CodeSynthesisContext::DefaultTemplateArgumentInstantiation:
678 case CodeSynthesisContext::PriorTemplateArgumentSubstitution:
679 case CodeSynthesisContext::DefaultTemplateArgumentChecking:
680 // A default template argument instantiation and substitution into
681 // template parameters with arguments for prior parameters may or may
682 // not be a SFINAE context; look further up the stack.
685 case CodeSynthesisContext::ExplicitTemplateArgumentSubstitution:
686 case CodeSynthesisContext::DeducedTemplateArgumentSubstitution:
687 // We're either substitution explicitly-specified template arguments
688 // or deduced template arguments, so SFINAE applies.
689 assert(Active->DeductionInfo && "Missing deduction info pointer");
690 return Active->DeductionInfo;
692 case CodeSynthesisContext::DeclaringSpecialMember:
693 case CodeSynthesisContext::DefiningSynthesizedFunction:
694 // This happens in a context unrelated to template instantiation, so
695 // there is no SFINAE.
698 case CodeSynthesisContext::Memoization:
702 // The inner context was transparent for SFINAE. If it occurred within a
703 // non-instantiation SFINAE context, then SFINAE applies.
704 if (Active->SavedInNonInstantiationSFINAEContext)
705 return Optional<TemplateDeductionInfo *>(nullptr);
711 //===----------------------------------------------------------------------===/
712 // Template Instantiation for Types
713 //===----------------------------------------------------------------------===/
715 class TemplateInstantiator : public TreeTransform<TemplateInstantiator> {
716 const MultiLevelTemplateArgumentList &TemplateArgs;
718 DeclarationName Entity;
721 typedef TreeTransform<TemplateInstantiator> inherited;
723 TemplateInstantiator(Sema &SemaRef,
724 const MultiLevelTemplateArgumentList &TemplateArgs,
726 DeclarationName Entity)
727 : inherited(SemaRef), TemplateArgs(TemplateArgs), Loc(Loc),
730 /// Determine whether the given type \p T has already been
733 /// For the purposes of template instantiation, a type has already been
734 /// transformed if it is NULL or if it is not dependent.
735 bool AlreadyTransformed(QualType T);
737 /// Returns the location of the entity being instantiated, if known.
738 SourceLocation getBaseLocation() { return Loc; }
740 /// Returns the name of the entity being instantiated, if any.
741 DeclarationName getBaseEntity() { return Entity; }
743 /// Sets the "base" location and entity when that
744 /// information is known based on another transformation.
745 void setBase(SourceLocation Loc, DeclarationName Entity) {
747 this->Entity = Entity;
750 bool TryExpandParameterPacks(SourceLocation EllipsisLoc,
751 SourceRange PatternRange,
752 ArrayRef<UnexpandedParameterPack> Unexpanded,
753 bool &ShouldExpand, bool &RetainExpansion,
754 Optional<unsigned> &NumExpansions) {
755 return getSema().CheckParameterPacksForExpansion(EllipsisLoc,
756 PatternRange, Unexpanded,
763 void ExpandingFunctionParameterPack(ParmVarDecl *Pack) {
764 SemaRef.CurrentInstantiationScope->MakeInstantiatedLocalArgPack(Pack);
767 TemplateArgument ForgetPartiallySubstitutedPack() {
768 TemplateArgument Result;
769 if (NamedDecl *PartialPack
770 = SemaRef.CurrentInstantiationScope->getPartiallySubstitutedPack()){
771 MultiLevelTemplateArgumentList &TemplateArgs
772 = const_cast<MultiLevelTemplateArgumentList &>(this->TemplateArgs);
773 unsigned Depth, Index;
774 std::tie(Depth, Index) = getDepthAndIndex(PartialPack);
775 if (TemplateArgs.hasTemplateArgument(Depth, Index)) {
776 Result = TemplateArgs(Depth, Index);
777 TemplateArgs.setArgument(Depth, Index, TemplateArgument());
784 void RememberPartiallySubstitutedPack(TemplateArgument Arg) {
788 if (NamedDecl *PartialPack
789 = SemaRef.CurrentInstantiationScope->getPartiallySubstitutedPack()){
790 MultiLevelTemplateArgumentList &TemplateArgs
791 = const_cast<MultiLevelTemplateArgumentList &>(this->TemplateArgs);
792 unsigned Depth, Index;
793 std::tie(Depth, Index) = getDepthAndIndex(PartialPack);
794 TemplateArgs.setArgument(Depth, Index, Arg);
798 /// Transform the given declaration by instantiating a reference to
799 /// this declaration.
800 Decl *TransformDecl(SourceLocation Loc, Decl *D);
802 void transformAttrs(Decl *Old, Decl *New) {
803 SemaRef.InstantiateAttrs(TemplateArgs, Old, New);
806 void transformedLocalDecl(Decl *Old, Decl *New) {
807 // If we've instantiated the call operator of a lambda or the call
808 // operator template of a generic lambda, update the "instantiation of"
810 auto *NewMD = dyn_cast<CXXMethodDecl>(New);
811 if (NewMD && isLambdaCallOperator(NewMD)) {
812 auto *OldMD = dyn_cast<CXXMethodDecl>(Old);
813 if (auto *NewTD = NewMD->getDescribedFunctionTemplate())
814 NewTD->setInstantiatedFromMemberTemplate(
815 OldMD->getDescribedFunctionTemplate());
817 NewMD->setInstantiationOfMemberFunction(OldMD,
818 TSK_ImplicitInstantiation);
821 SemaRef.CurrentInstantiationScope->InstantiatedLocal(Old, New);
823 // We recreated a local declaration, but not by instantiating it. There
824 // may be pending dependent diagnostics to produce.
825 if (auto *DC = dyn_cast<DeclContext>(Old))
826 SemaRef.PerformDependentDiagnostics(DC, TemplateArgs);
829 /// Transform the definition of the given declaration by
830 /// instantiating it.
831 Decl *TransformDefinition(SourceLocation Loc, Decl *D);
833 /// Transform the first qualifier within a scope by instantiating the
835 NamedDecl *TransformFirstQualifierInScope(NamedDecl *D, SourceLocation Loc);
837 /// Rebuild the exception declaration and register the declaration
838 /// as an instantiated local.
839 VarDecl *RebuildExceptionDecl(VarDecl *ExceptionDecl,
840 TypeSourceInfo *Declarator,
841 SourceLocation StartLoc,
842 SourceLocation NameLoc,
843 IdentifierInfo *Name);
845 /// Rebuild the Objective-C exception declaration and register the
846 /// declaration as an instantiated local.
847 VarDecl *RebuildObjCExceptionDecl(VarDecl *ExceptionDecl,
848 TypeSourceInfo *TSInfo, QualType T);
850 /// Check for tag mismatches when instantiating an
852 QualType RebuildElaboratedType(SourceLocation KeywordLoc,
853 ElaboratedTypeKeyword Keyword,
854 NestedNameSpecifierLoc QualifierLoc,
858 TransformTemplateName(CXXScopeSpec &SS, TemplateName Name,
859 SourceLocation NameLoc,
860 QualType ObjectType = QualType(),
861 NamedDecl *FirstQualifierInScope = nullptr,
862 bool AllowInjectedClassName = false);
864 const LoopHintAttr *TransformLoopHintAttr(const LoopHintAttr *LH);
866 ExprResult TransformPredefinedExpr(PredefinedExpr *E);
867 ExprResult TransformDeclRefExpr(DeclRefExpr *E);
868 ExprResult TransformCXXDefaultArgExpr(CXXDefaultArgExpr *E);
870 ExprResult TransformTemplateParmRefExpr(DeclRefExpr *E,
871 NonTypeTemplateParmDecl *D);
872 ExprResult TransformSubstNonTypeTemplateParmPackExpr(
873 SubstNonTypeTemplateParmPackExpr *E);
875 /// Rebuild a DeclRefExpr for a ParmVarDecl reference.
876 ExprResult RebuildParmVarDeclRefExpr(ParmVarDecl *PD, SourceLocation Loc);
878 /// Transform a reference to a function parameter pack.
879 ExprResult TransformFunctionParmPackRefExpr(DeclRefExpr *E,
882 /// Transform a FunctionParmPackExpr which was built when we couldn't
883 /// expand a function parameter pack reference which refers to an expanded
885 ExprResult TransformFunctionParmPackExpr(FunctionParmPackExpr *E);
887 QualType TransformFunctionProtoType(TypeLocBuilder &TLB,
888 FunctionProtoTypeLoc TL) {
889 // Call the base version; it will forward to our overridden version below.
890 return inherited::TransformFunctionProtoType(TLB, TL);
893 template<typename Fn>
894 QualType TransformFunctionProtoType(TypeLocBuilder &TLB,
895 FunctionProtoTypeLoc TL,
896 CXXRecordDecl *ThisContext,
897 unsigned ThisTypeQuals,
898 Fn TransformExceptionSpec);
900 ParmVarDecl *TransformFunctionTypeParam(ParmVarDecl *OldParm,
902 Optional<unsigned> NumExpansions,
903 bool ExpectParameterPack);
905 /// Transforms a template type parameter type by performing
906 /// substitution of the corresponding template type argument.
907 QualType TransformTemplateTypeParmType(TypeLocBuilder &TLB,
908 TemplateTypeParmTypeLoc TL);
910 /// Transforms an already-substituted template type parameter pack
911 /// into either itself (if we aren't substituting into its pack expansion)
912 /// or the appropriate substituted argument.
913 QualType TransformSubstTemplateTypeParmPackType(TypeLocBuilder &TLB,
914 SubstTemplateTypeParmPackTypeLoc TL);
916 ExprResult TransformLambdaExpr(LambdaExpr *E) {
917 LocalInstantiationScope Scope(SemaRef, /*CombineWithOuterScope=*/true);
918 return TreeTransform<TemplateInstantiator>::TransformLambdaExpr(E);
921 TemplateParameterList *TransformTemplateParameterList(
922 TemplateParameterList *OrigTPL) {
923 if (!OrigTPL || !OrigTPL->size()) return OrigTPL;
925 DeclContext *Owner = OrigTPL->getParam(0)->getDeclContext();
926 TemplateDeclInstantiator DeclInstantiator(getSema(),
927 /* DeclContext *Owner */ Owner, TemplateArgs);
928 return DeclInstantiator.SubstTemplateParams(OrigTPL);
931 ExprResult transformNonTypeTemplateParmRef(NonTypeTemplateParmDecl *parm,
933 TemplateArgument arg);
937 bool TemplateInstantiator::AlreadyTransformed(QualType T) {
941 if (T->isInstantiationDependentType() || T->isVariablyModifiedType())
944 getSema().MarkDeclarationsReferencedInType(Loc, T);
948 static TemplateArgument
949 getPackSubstitutedTemplateArgument(Sema &S, TemplateArgument Arg) {
950 assert(S.ArgumentPackSubstitutionIndex >= 0);
951 assert(S.ArgumentPackSubstitutionIndex < (int)Arg.pack_size());
952 Arg = Arg.pack_begin()[S.ArgumentPackSubstitutionIndex];
953 if (Arg.isPackExpansion())
954 Arg = Arg.getPackExpansionPattern();
958 Decl *TemplateInstantiator::TransformDecl(SourceLocation Loc, Decl *D) {
962 if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(D)) {
963 if (TTP->getDepth() < TemplateArgs.getNumLevels()) {
964 // If the corresponding template argument is NULL or non-existent, it's
965 // because we are performing instantiation from explicitly-specified
966 // template arguments in a function template, but there were some
967 // arguments left unspecified.
968 if (!TemplateArgs.hasTemplateArgument(TTP->getDepth(),
972 TemplateArgument Arg = TemplateArgs(TTP->getDepth(), TTP->getPosition());
974 if (TTP->isParameterPack()) {
975 assert(Arg.getKind() == TemplateArgument::Pack &&
976 "Missing argument pack");
977 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
980 TemplateName Template = Arg.getAsTemplate().getNameToSubstitute();
981 assert(!Template.isNull() && Template.getAsTemplateDecl() &&
982 "Wrong kind of template template argument");
983 return Template.getAsTemplateDecl();
986 // Fall through to find the instantiated declaration for this template
987 // template parameter.
990 return SemaRef.FindInstantiatedDecl(Loc, cast<NamedDecl>(D), TemplateArgs);
993 Decl *TemplateInstantiator::TransformDefinition(SourceLocation Loc, Decl *D) {
994 Decl *Inst = getSema().SubstDecl(D, getSema().CurContext, TemplateArgs);
998 getSema().CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1003 TemplateInstantiator::TransformFirstQualifierInScope(NamedDecl *D,
1004 SourceLocation Loc) {
1005 // If the first part of the nested-name-specifier was a template type
1006 // parameter, instantiate that type parameter down to a tag type.
1007 if (TemplateTypeParmDecl *TTPD = dyn_cast_or_null<TemplateTypeParmDecl>(D)) {
1008 const TemplateTypeParmType *TTP
1009 = cast<TemplateTypeParmType>(getSema().Context.getTypeDeclType(TTPD));
1011 if (TTP->getDepth() < TemplateArgs.getNumLevels()) {
1012 // FIXME: This needs testing w/ member access expressions.
1013 TemplateArgument Arg = TemplateArgs(TTP->getDepth(), TTP->getIndex());
1015 if (TTP->isParameterPack()) {
1016 assert(Arg.getKind() == TemplateArgument::Pack &&
1017 "Missing argument pack");
1019 if (getSema().ArgumentPackSubstitutionIndex == -1)
1022 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1025 QualType T = Arg.getAsType();
1027 return cast_or_null<NamedDecl>(TransformDecl(Loc, D));
1029 if (const TagType *Tag = T->getAs<TagType>())
1030 return Tag->getDecl();
1032 // The resulting type is not a tag; complain.
1033 getSema().Diag(Loc, diag::err_nested_name_spec_non_tag) << T;
1038 return cast_or_null<NamedDecl>(TransformDecl(Loc, D));
1042 TemplateInstantiator::RebuildExceptionDecl(VarDecl *ExceptionDecl,
1043 TypeSourceInfo *Declarator,
1044 SourceLocation StartLoc,
1045 SourceLocation NameLoc,
1046 IdentifierInfo *Name) {
1047 VarDecl *Var = inherited::RebuildExceptionDecl(ExceptionDecl, Declarator,
1048 StartLoc, NameLoc, Name);
1050 getSema().CurrentInstantiationScope->InstantiatedLocal(ExceptionDecl, Var);
1054 VarDecl *TemplateInstantiator::RebuildObjCExceptionDecl(VarDecl *ExceptionDecl,
1055 TypeSourceInfo *TSInfo,
1057 VarDecl *Var = inherited::RebuildObjCExceptionDecl(ExceptionDecl, TSInfo, T);
1059 getSema().CurrentInstantiationScope->InstantiatedLocal(ExceptionDecl, Var);
1064 TemplateInstantiator::RebuildElaboratedType(SourceLocation KeywordLoc,
1065 ElaboratedTypeKeyword Keyword,
1066 NestedNameSpecifierLoc QualifierLoc,
1068 if (const TagType *TT = T->getAs<TagType>()) {
1069 TagDecl* TD = TT->getDecl();
1071 SourceLocation TagLocation = KeywordLoc;
1073 IdentifierInfo *Id = TD->getIdentifier();
1075 // TODO: should we even warn on struct/class mismatches for this? Seems
1076 // like it's likely to produce a lot of spurious errors.
1077 if (Id && Keyword != ETK_None && Keyword != ETK_Typename) {
1078 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForKeyword(Keyword);
1079 if (!SemaRef.isAcceptableTagRedeclaration(TD, Kind, /*isDefinition*/false,
1081 SemaRef.Diag(TagLocation, diag::err_use_with_wrong_tag)
1083 << FixItHint::CreateReplacement(SourceRange(TagLocation),
1085 SemaRef.Diag(TD->getLocation(), diag::note_previous_use);
1090 return TreeTransform<TemplateInstantiator>::RebuildElaboratedType(KeywordLoc,
1096 TemplateName TemplateInstantiator::TransformTemplateName(
1097 CXXScopeSpec &SS, TemplateName Name, SourceLocation NameLoc,
1098 QualType ObjectType, NamedDecl *FirstQualifierInScope,
1099 bool AllowInjectedClassName) {
1100 if (TemplateTemplateParmDecl *TTP
1101 = dyn_cast_or_null<TemplateTemplateParmDecl>(Name.getAsTemplateDecl())) {
1102 if (TTP->getDepth() < TemplateArgs.getNumLevels()) {
1103 // If the corresponding template argument is NULL or non-existent, it's
1104 // because we are performing instantiation from explicitly-specified
1105 // template arguments in a function template, but there were some
1106 // arguments left unspecified.
1107 if (!TemplateArgs.hasTemplateArgument(TTP->getDepth(),
1108 TTP->getPosition()))
1111 TemplateArgument Arg = TemplateArgs(TTP->getDepth(), TTP->getPosition());
1113 if (TTP->isParameterPack()) {
1114 assert(Arg.getKind() == TemplateArgument::Pack &&
1115 "Missing argument pack");
1117 if (getSema().ArgumentPackSubstitutionIndex == -1) {
1118 // We have the template argument pack to substitute, but we're not
1119 // actually expanding the enclosing pack expansion yet. So, just
1120 // keep the entire argument pack.
1121 return getSema().Context.getSubstTemplateTemplateParmPack(TTP, Arg);
1124 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1127 TemplateName Template = Arg.getAsTemplate().getNameToSubstitute();
1128 assert(!Template.isNull() && "Null template template argument");
1129 assert(!Template.getAsQualifiedTemplateName() &&
1130 "template decl to substitute is qualified?");
1132 Template = getSema().Context.getSubstTemplateTemplateParm(TTP, Template);
1137 if (SubstTemplateTemplateParmPackStorage *SubstPack
1138 = Name.getAsSubstTemplateTemplateParmPack()) {
1139 if (getSema().ArgumentPackSubstitutionIndex == -1)
1142 TemplateArgument Arg = SubstPack->getArgumentPack();
1143 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1144 return Arg.getAsTemplate().getNameToSubstitute();
1147 return inherited::TransformTemplateName(SS, Name, NameLoc, ObjectType,
1148 FirstQualifierInScope,
1149 AllowInjectedClassName);
1153 TemplateInstantiator::TransformPredefinedExpr(PredefinedExpr *E) {
1154 if (!E->isTypeDependent())
1157 return getSema().BuildPredefinedExpr(E->getLocation(), E->getIdentType());
1161 TemplateInstantiator::TransformTemplateParmRefExpr(DeclRefExpr *E,
1162 NonTypeTemplateParmDecl *NTTP) {
1163 // If the corresponding template argument is NULL or non-existent, it's
1164 // because we are performing instantiation from explicitly-specified
1165 // template arguments in a function template, but there were some
1166 // arguments left unspecified.
1167 if (!TemplateArgs.hasTemplateArgument(NTTP->getDepth(),
1168 NTTP->getPosition()))
1171 TemplateArgument Arg = TemplateArgs(NTTP->getDepth(), NTTP->getPosition());
1173 if (TemplateArgs.getNumLevels() != TemplateArgs.getNumSubstitutedLevels()) {
1174 // We're performing a partial substitution, so the substituted argument
1175 // could be dependent. As a result we can't create a SubstNonType*Expr
1176 // node now, since that represents a fully-substituted argument.
1177 // FIXME: We should have some AST representation for this.
1178 if (Arg.getKind() == TemplateArgument::Pack) {
1179 // FIXME: This won't work for alias templates.
1180 assert(Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion() &&
1181 "unexpected pack arguments in partial substitution");
1182 Arg = Arg.pack_begin()->getPackExpansionPattern();
1184 assert(Arg.getKind() == TemplateArgument::Expression &&
1185 "unexpected nontype template argument kind in partial substitution");
1186 return Arg.getAsExpr();
1189 if (NTTP->isParameterPack()) {
1190 assert(Arg.getKind() == TemplateArgument::Pack &&
1191 "Missing argument pack");
1193 if (getSema().ArgumentPackSubstitutionIndex == -1) {
1194 // We have an argument pack, but we can't select a particular argument
1195 // out of it yet. Therefore, we'll build an expression to hold on to that
1197 QualType TargetType = SemaRef.SubstType(NTTP->getType(), TemplateArgs,
1199 NTTP->getDeclName());
1200 if (TargetType.isNull())
1203 return new (SemaRef.Context) SubstNonTypeTemplateParmPackExpr(
1204 TargetType.getNonLValueExprType(SemaRef.Context),
1205 TargetType->isReferenceType() ? VK_LValue : VK_RValue, NTTP,
1206 E->getLocation(), Arg);
1209 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1212 return transformNonTypeTemplateParmRef(NTTP, E->getLocation(), Arg);
1215 const LoopHintAttr *
1216 TemplateInstantiator::TransformLoopHintAttr(const LoopHintAttr *LH) {
1217 Expr *TransformedExpr = getDerived().TransformExpr(LH->getValue()).get();
1219 if (TransformedExpr == LH->getValue())
1222 // Generate error if there is a problem with the value.
1223 if (getSema().CheckLoopHintExpr(TransformedExpr, LH->getLocation()))
1226 // Create new LoopHintValueAttr with integral expression in place of the
1227 // non-type template parameter.
1228 return LoopHintAttr::CreateImplicit(
1229 getSema().Context, LH->getSemanticSpelling(), LH->getOption(),
1230 LH->getState(), TransformedExpr, LH->getRange());
1233 ExprResult TemplateInstantiator::transformNonTypeTemplateParmRef(
1234 NonTypeTemplateParmDecl *parm,
1236 TemplateArgument arg) {
1240 // The template argument itself might be an expression, in which
1241 // case we just return that expression.
1242 if (arg.getKind() == TemplateArgument::Expression) {
1243 Expr *argExpr = arg.getAsExpr();
1245 type = argExpr->getType();
1247 } else if (arg.getKind() == TemplateArgument::Declaration ||
1248 arg.getKind() == TemplateArgument::NullPtr) {
1250 if (arg.getKind() == TemplateArgument::Declaration) {
1251 VD = arg.getAsDecl();
1253 // Find the instantiation of the template argument. This is
1254 // required for nested templates.
1255 VD = cast_or_null<ValueDecl>(
1256 getSema().FindInstantiatedDecl(loc, VD, TemplateArgs));
1260 // Propagate NULL template argument.
1264 // Derive the type we want the substituted decl to have. This had
1265 // better be non-dependent, or these checks will have serious problems.
1266 if (parm->isExpandedParameterPack()) {
1267 type = parm->getExpansionType(SemaRef.ArgumentPackSubstitutionIndex);
1268 } else if (parm->isParameterPack() &&
1269 isa<PackExpansionType>(parm->getType())) {
1270 type = SemaRef.SubstType(
1271 cast<PackExpansionType>(parm->getType())->getPattern(),
1272 TemplateArgs, loc, parm->getDeclName());
1274 type = SemaRef.SubstType(VD ? arg.getParamTypeForDecl() : arg.getNullPtrType(),
1275 TemplateArgs, loc, parm->getDeclName());
1277 assert(!type.isNull() && "type substitution failed for param type");
1278 assert(!type->isDependentType() && "param type still dependent");
1279 result = SemaRef.BuildExpressionFromDeclTemplateArgument(arg, type, loc);
1281 if (!result.isInvalid()) type = result.get()->getType();
1283 result = SemaRef.BuildExpressionFromIntegralTemplateArgument(arg, loc);
1285 // Note that this type can be different from the type of 'result',
1286 // e.g. if it's an enum type.
1287 type = arg.getIntegralType();
1289 if (result.isInvalid()) return ExprError();
1291 Expr *resultExpr = result.get();
1292 return new (SemaRef.Context) SubstNonTypeTemplateParmExpr(
1293 type, resultExpr->getValueKind(), loc, parm, resultExpr);
1297 TemplateInstantiator::TransformSubstNonTypeTemplateParmPackExpr(
1298 SubstNonTypeTemplateParmPackExpr *E) {
1299 if (getSema().ArgumentPackSubstitutionIndex == -1) {
1300 // We aren't expanding the parameter pack, so just return ourselves.
1304 TemplateArgument Arg = E->getArgumentPack();
1305 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1306 return transformNonTypeTemplateParmRef(E->getParameterPack(),
1307 E->getParameterPackLocation(),
1312 TemplateInstantiator::RebuildParmVarDeclRefExpr(ParmVarDecl *PD,
1313 SourceLocation Loc) {
1314 DeclarationNameInfo NameInfo(PD->getDeclName(), Loc);
1315 return getSema().BuildDeclarationNameExpr(CXXScopeSpec(), NameInfo, PD);
1319 TemplateInstantiator::TransformFunctionParmPackExpr(FunctionParmPackExpr *E) {
1320 if (getSema().ArgumentPackSubstitutionIndex != -1) {
1321 // We can expand this parameter pack now.
1322 ParmVarDecl *D = E->getExpansion(getSema().ArgumentPackSubstitutionIndex);
1323 ValueDecl *VD = cast_or_null<ValueDecl>(TransformDecl(E->getExprLoc(), D));
1326 return RebuildParmVarDeclRefExpr(cast<ParmVarDecl>(VD), E->getExprLoc());
1329 QualType T = TransformType(E->getType());
1333 // Transform each of the parameter expansions into the corresponding
1334 // parameters in the instantiation of the function decl.
1335 SmallVector<ParmVarDecl *, 8> Parms;
1336 Parms.reserve(E->getNumExpansions());
1337 for (FunctionParmPackExpr::iterator I = E->begin(), End = E->end();
1340 cast_or_null<ParmVarDecl>(TransformDecl(E->getExprLoc(), *I));
1346 return FunctionParmPackExpr::Create(getSema().Context, T,
1347 E->getParameterPack(),
1348 E->getParameterPackLocation(), Parms);
1352 TemplateInstantiator::TransformFunctionParmPackRefExpr(DeclRefExpr *E,
1354 typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack;
1355 llvm::PointerUnion<Decl *, DeclArgumentPack *> *Found
1356 = getSema().CurrentInstantiationScope->findInstantiationOf(PD);
1357 assert(Found && "no instantiation for parameter pack");
1359 Decl *TransformedDecl;
1360 if (DeclArgumentPack *Pack = Found->dyn_cast<DeclArgumentPack *>()) {
1361 // If this is a reference to a function parameter pack which we can
1362 // substitute but can't yet expand, build a FunctionParmPackExpr for it.
1363 if (getSema().ArgumentPackSubstitutionIndex == -1) {
1364 QualType T = TransformType(E->getType());
1367 return FunctionParmPackExpr::Create(getSema().Context, T, PD,
1368 E->getExprLoc(), *Pack);
1371 TransformedDecl = (*Pack)[getSema().ArgumentPackSubstitutionIndex];
1373 TransformedDecl = Found->get<Decl*>();
1376 // We have either an unexpanded pack or a specific expansion.
1377 return RebuildParmVarDeclRefExpr(cast<ParmVarDecl>(TransformedDecl),
1382 TemplateInstantiator::TransformDeclRefExpr(DeclRefExpr *E) {
1383 NamedDecl *D = E->getDecl();
1385 // Handle references to non-type template parameters and non-type template
1387 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(D)) {
1388 if (NTTP->getDepth() < TemplateArgs.getNumLevels())
1389 return TransformTemplateParmRefExpr(E, NTTP);
1391 // We have a non-type template parameter that isn't fully substituted;
1392 // FindInstantiatedDecl will find it in the local instantiation scope.
1395 // Handle references to function parameter packs.
1396 if (ParmVarDecl *PD = dyn_cast<ParmVarDecl>(D))
1397 if (PD->isParameterPack())
1398 return TransformFunctionParmPackRefExpr(E, PD);
1400 return TreeTransform<TemplateInstantiator>::TransformDeclRefExpr(E);
1403 ExprResult TemplateInstantiator::TransformCXXDefaultArgExpr(
1404 CXXDefaultArgExpr *E) {
1405 assert(!cast<FunctionDecl>(E->getParam()->getDeclContext())->
1406 getDescribedFunctionTemplate() &&
1407 "Default arg expressions are never formed in dependent cases.");
1408 return SemaRef.BuildCXXDefaultArgExpr(E->getUsedLocation(),
1409 cast<FunctionDecl>(E->getParam()->getDeclContext()),
1413 template<typename Fn>
1414 QualType TemplateInstantiator::TransformFunctionProtoType(TypeLocBuilder &TLB,
1415 FunctionProtoTypeLoc TL,
1416 CXXRecordDecl *ThisContext,
1417 unsigned ThisTypeQuals,
1418 Fn TransformExceptionSpec) {
1419 // We need a local instantiation scope for this function prototype.
1420 LocalInstantiationScope Scope(SemaRef, /*CombineWithOuterScope=*/true);
1421 return inherited::TransformFunctionProtoType(
1422 TLB, TL, ThisContext, ThisTypeQuals, TransformExceptionSpec);
1426 TemplateInstantiator::TransformFunctionTypeParam(ParmVarDecl *OldParm,
1427 int indexAdjustment,
1428 Optional<unsigned> NumExpansions,
1429 bool ExpectParameterPack) {
1430 return SemaRef.SubstParmVarDecl(OldParm, TemplateArgs, indexAdjustment,
1431 NumExpansions, ExpectParameterPack);
1435 TemplateInstantiator::TransformTemplateTypeParmType(TypeLocBuilder &TLB,
1436 TemplateTypeParmTypeLoc TL) {
1437 const TemplateTypeParmType *T = TL.getTypePtr();
1438 if (T->getDepth() < TemplateArgs.getNumLevels()) {
1439 // Replace the template type parameter with its corresponding
1440 // template argument.
1442 // If the corresponding template argument is NULL or doesn't exist, it's
1443 // because we are performing instantiation from explicitly-specified
1444 // template arguments in a function template class, but there were some
1445 // arguments left unspecified.
1446 if (!TemplateArgs.hasTemplateArgument(T->getDepth(), T->getIndex())) {
1447 TemplateTypeParmTypeLoc NewTL
1448 = TLB.push<TemplateTypeParmTypeLoc>(TL.getType());
1449 NewTL.setNameLoc(TL.getNameLoc());
1450 return TL.getType();
1453 TemplateArgument Arg = TemplateArgs(T->getDepth(), T->getIndex());
1455 if (T->isParameterPack()) {
1456 assert(Arg.getKind() == TemplateArgument::Pack &&
1457 "Missing argument pack");
1459 if (getSema().ArgumentPackSubstitutionIndex == -1) {
1460 // We have the template argument pack, but we're not expanding the
1461 // enclosing pack expansion yet. Just save the template argument
1462 // pack for later substitution.
1464 = getSema().Context.getSubstTemplateTypeParmPackType(T, Arg);
1465 SubstTemplateTypeParmPackTypeLoc NewTL
1466 = TLB.push<SubstTemplateTypeParmPackTypeLoc>(Result);
1467 NewTL.setNameLoc(TL.getNameLoc());
1471 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1474 assert(Arg.getKind() == TemplateArgument::Type &&
1475 "Template argument kind mismatch");
1477 QualType Replacement = Arg.getAsType();
1479 // TODO: only do this uniquing once, at the start of instantiation.
1481 = getSema().Context.getSubstTemplateTypeParmType(T, Replacement);
1482 SubstTemplateTypeParmTypeLoc NewTL
1483 = TLB.push<SubstTemplateTypeParmTypeLoc>(Result);
1484 NewTL.setNameLoc(TL.getNameLoc());
1488 // The template type parameter comes from an inner template (e.g.,
1489 // the template parameter list of a member template inside the
1490 // template we are instantiating). Create a new template type
1491 // parameter with the template "level" reduced by one.
1492 TemplateTypeParmDecl *NewTTPDecl = nullptr;
1493 if (TemplateTypeParmDecl *OldTTPDecl = T->getDecl())
1494 NewTTPDecl = cast_or_null<TemplateTypeParmDecl>(
1495 TransformDecl(TL.getNameLoc(), OldTTPDecl));
1497 QualType Result = getSema().Context.getTemplateTypeParmType(
1498 T->getDepth() - TemplateArgs.getNumSubstitutedLevels(), T->getIndex(),
1499 T->isParameterPack(), NewTTPDecl);
1500 TemplateTypeParmTypeLoc NewTL = TLB.push<TemplateTypeParmTypeLoc>(Result);
1501 NewTL.setNameLoc(TL.getNameLoc());
1506 TemplateInstantiator::TransformSubstTemplateTypeParmPackType(
1507 TypeLocBuilder &TLB,
1508 SubstTemplateTypeParmPackTypeLoc TL) {
1509 if (getSema().ArgumentPackSubstitutionIndex == -1) {
1510 // We aren't expanding the parameter pack, so just return ourselves.
1511 SubstTemplateTypeParmPackTypeLoc NewTL
1512 = TLB.push<SubstTemplateTypeParmPackTypeLoc>(TL.getType());
1513 NewTL.setNameLoc(TL.getNameLoc());
1514 return TL.getType();
1517 TemplateArgument Arg = TL.getTypePtr()->getArgumentPack();
1518 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1519 QualType Result = Arg.getAsType();
1521 Result = getSema().Context.getSubstTemplateTypeParmType(
1522 TL.getTypePtr()->getReplacedParameter(),
1524 SubstTemplateTypeParmTypeLoc NewTL
1525 = TLB.push<SubstTemplateTypeParmTypeLoc>(Result);
1526 NewTL.setNameLoc(TL.getNameLoc());
1530 /// Perform substitution on the type T with a given set of template
1533 /// This routine substitutes the given template arguments into the
1534 /// type T and produces the instantiated type.
1536 /// \param T the type into which the template arguments will be
1537 /// substituted. If this type is not dependent, it will be returned
1540 /// \param Args the template arguments that will be
1541 /// substituted for the top-level template parameters within T.
1543 /// \param Loc the location in the source code where this substitution
1544 /// is being performed. It will typically be the location of the
1545 /// declarator (if we're instantiating the type of some declaration)
1546 /// or the location of the type in the source code (if, e.g., we're
1547 /// instantiating the type of a cast expression).
1549 /// \param Entity the name of the entity associated with a declaration
1550 /// being instantiated (if any). May be empty to indicate that there
1551 /// is no such entity (if, e.g., this is a type that occurs as part of
1552 /// a cast expression) or that the entity has no name (e.g., an
1553 /// unnamed function parameter).
1555 /// \param AllowDeducedTST Whether a DeducedTemplateSpecializationType is
1556 /// acceptable as the top level type of the result.
1558 /// \returns If the instantiation succeeds, the instantiated
1559 /// type. Otherwise, produces diagnostics and returns a NULL type.
1560 TypeSourceInfo *Sema::SubstType(TypeSourceInfo *T,
1561 const MultiLevelTemplateArgumentList &Args,
1563 DeclarationName Entity,
1564 bool AllowDeducedTST) {
1565 assert(!CodeSynthesisContexts.empty() &&
1566 "Cannot perform an instantiation without some context on the "
1567 "instantiation stack");
1569 if (!T->getType()->isInstantiationDependentType() &&
1570 !T->getType()->isVariablyModifiedType())
1573 TemplateInstantiator Instantiator(*this, Args, Loc, Entity);
1574 return AllowDeducedTST ? Instantiator.TransformTypeWithDeducedTST(T)
1575 : Instantiator.TransformType(T);
1578 TypeSourceInfo *Sema::SubstType(TypeLoc TL,
1579 const MultiLevelTemplateArgumentList &Args,
1581 DeclarationName Entity) {
1582 assert(!CodeSynthesisContexts.empty() &&
1583 "Cannot perform an instantiation without some context on the "
1584 "instantiation stack");
1586 if (TL.getType().isNull())
1589 if (!TL.getType()->isInstantiationDependentType() &&
1590 !TL.getType()->isVariablyModifiedType()) {
1591 // FIXME: Make a copy of the TypeLoc data here, so that we can
1592 // return a new TypeSourceInfo. Inefficient!
1594 TLB.pushFullCopy(TL);
1595 return TLB.getTypeSourceInfo(Context, TL.getType());
1598 TemplateInstantiator Instantiator(*this, Args, Loc, Entity);
1600 TLB.reserve(TL.getFullDataSize());
1601 QualType Result = Instantiator.TransformType(TLB, TL);
1602 if (Result.isNull())
1605 return TLB.getTypeSourceInfo(Context, Result);
1608 /// Deprecated form of the above.
1609 QualType Sema::SubstType(QualType T,
1610 const MultiLevelTemplateArgumentList &TemplateArgs,
1611 SourceLocation Loc, DeclarationName Entity) {
1612 assert(!CodeSynthesisContexts.empty() &&
1613 "Cannot perform an instantiation without some context on the "
1614 "instantiation stack");
1616 // If T is not a dependent type or a variably-modified type, there
1617 // is nothing to do.
1618 if (!T->isInstantiationDependentType() && !T->isVariablyModifiedType())
1621 TemplateInstantiator Instantiator(*this, TemplateArgs, Loc, Entity);
1622 return Instantiator.TransformType(T);
1625 static bool NeedsInstantiationAsFunctionType(TypeSourceInfo *T) {
1626 if (T->getType()->isInstantiationDependentType() ||
1627 T->getType()->isVariablyModifiedType())
1630 TypeLoc TL = T->getTypeLoc().IgnoreParens();
1631 if (!TL.getAs<FunctionProtoTypeLoc>())
1634 FunctionProtoTypeLoc FP = TL.castAs<FunctionProtoTypeLoc>();
1635 for (ParmVarDecl *P : FP.getParams()) {
1636 // This must be synthesized from a typedef.
1639 // If there are any parameters, a new TypeSourceInfo that refers to the
1640 // instantiated parameters must be built.
1647 /// A form of SubstType intended specifically for instantiating the
1648 /// type of a FunctionDecl. Its purpose is solely to force the
1649 /// instantiation of default-argument expressions and to avoid
1650 /// instantiating an exception-specification.
1651 TypeSourceInfo *Sema::SubstFunctionDeclType(TypeSourceInfo *T,
1652 const MultiLevelTemplateArgumentList &Args,
1654 DeclarationName Entity,
1655 CXXRecordDecl *ThisContext,
1656 unsigned ThisTypeQuals) {
1657 assert(!CodeSynthesisContexts.empty() &&
1658 "Cannot perform an instantiation without some context on the "
1659 "instantiation stack");
1661 if (!NeedsInstantiationAsFunctionType(T))
1664 TemplateInstantiator Instantiator(*this, Args, Loc, Entity);
1668 TypeLoc TL = T->getTypeLoc();
1669 TLB.reserve(TL.getFullDataSize());
1673 if (FunctionProtoTypeLoc Proto =
1674 TL.IgnoreParens().getAs<FunctionProtoTypeLoc>()) {
1675 // Instantiate the type, other than its exception specification. The
1676 // exception specification is instantiated in InitFunctionInstantiation
1677 // once we've built the FunctionDecl.
1678 // FIXME: Set the exception specification to EST_Uninstantiated here,
1679 // instead of rebuilding the function type again later.
1680 Result = Instantiator.TransformFunctionProtoType(
1681 TLB, Proto, ThisContext, ThisTypeQuals,
1682 [](FunctionProtoType::ExceptionSpecInfo &ESI,
1683 bool &Changed) { return false; });
1685 Result = Instantiator.TransformType(TLB, TL);
1687 if (Result.isNull())
1690 return TLB.getTypeSourceInfo(Context, Result);
1693 bool Sema::SubstExceptionSpec(SourceLocation Loc,
1694 FunctionProtoType::ExceptionSpecInfo &ESI,
1695 SmallVectorImpl<QualType> &ExceptionStorage,
1696 const MultiLevelTemplateArgumentList &Args) {
1697 assert(ESI.Type != EST_Uninstantiated);
1699 bool Changed = false;
1700 TemplateInstantiator Instantiator(*this, Args, Loc, DeclarationName());
1701 return Instantiator.TransformExceptionSpec(Loc, ESI, ExceptionStorage,
1705 void Sema::SubstExceptionSpec(FunctionDecl *New, const FunctionProtoType *Proto,
1706 const MultiLevelTemplateArgumentList &Args) {
1707 FunctionProtoType::ExceptionSpecInfo ESI =
1708 Proto->getExtProtoInfo().ExceptionSpec;
1710 SmallVector<QualType, 4> ExceptionStorage;
1711 if (SubstExceptionSpec(New->getTypeSourceInfo()->getTypeLoc().getLocEnd(),
1712 ESI, ExceptionStorage, Args))
1713 // On error, recover by dropping the exception specification.
1714 ESI.Type = EST_None;
1716 UpdateExceptionSpec(New, ESI);
1719 ParmVarDecl *Sema::SubstParmVarDecl(ParmVarDecl *OldParm,
1720 const MultiLevelTemplateArgumentList &TemplateArgs,
1721 int indexAdjustment,
1722 Optional<unsigned> NumExpansions,
1723 bool ExpectParameterPack) {
1724 TypeSourceInfo *OldDI = OldParm->getTypeSourceInfo();
1725 TypeSourceInfo *NewDI = nullptr;
1727 TypeLoc OldTL = OldDI->getTypeLoc();
1728 if (PackExpansionTypeLoc ExpansionTL = OldTL.getAs<PackExpansionTypeLoc>()) {
1730 // We have a function parameter pack. Substitute into the pattern of the
1732 NewDI = SubstType(ExpansionTL.getPatternLoc(), TemplateArgs,
1733 OldParm->getLocation(), OldParm->getDeclName());
1737 if (NewDI->getType()->containsUnexpandedParameterPack()) {
1738 // We still have unexpanded parameter packs, which means that
1739 // our function parameter is still a function parameter pack.
1740 // Therefore, make its type a pack expansion type.
1741 NewDI = CheckPackExpansion(NewDI, ExpansionTL.getEllipsisLoc(),
1743 } else if (ExpectParameterPack) {
1744 // We expected to get a parameter pack but didn't (because the type
1745 // itself is not a pack expansion type), so complain. This can occur when
1746 // the substitution goes through an alias template that "loses" the
1748 Diag(OldParm->getLocation(),
1749 diag::err_function_parameter_pack_without_parameter_packs)
1750 << NewDI->getType();
1754 NewDI = SubstType(OldDI, TemplateArgs, OldParm->getLocation(),
1755 OldParm->getDeclName());
1761 if (NewDI->getType()->isVoidType()) {
1762 Diag(OldParm->getLocation(), diag::err_param_with_void_type);
1766 ParmVarDecl *NewParm = CheckParameter(Context.getTranslationUnitDecl(),
1767 OldParm->getInnerLocStart(),
1768 OldParm->getLocation(),
1769 OldParm->getIdentifier(),
1770 NewDI->getType(), NewDI,
1771 OldParm->getStorageClass());
1775 // Mark the (new) default argument as uninstantiated (if any).
1776 if (OldParm->hasUninstantiatedDefaultArg()) {
1777 Expr *Arg = OldParm->getUninstantiatedDefaultArg();
1778 NewParm->setUninstantiatedDefaultArg(Arg);
1779 } else if (OldParm->hasUnparsedDefaultArg()) {
1780 NewParm->setUnparsedDefaultArg();
1781 UnparsedDefaultArgInstantiations[OldParm].push_back(NewParm);
1782 } else if (Expr *Arg = OldParm->getDefaultArg()) {
1783 FunctionDecl *OwningFunc = cast<FunctionDecl>(OldParm->getDeclContext());
1784 if (OwningFunc->isLexicallyWithinFunctionOrMethod()) {
1785 // Instantiate default arguments for methods of local classes (DR1484)
1786 // and non-defining declarations.
1787 Sema::ContextRAII SavedContext(*this, OwningFunc);
1788 LocalInstantiationScope Local(*this, true);
1789 ExprResult NewArg = SubstExpr(Arg, TemplateArgs);
1790 if (NewArg.isUsable()) {
1791 // It would be nice if we still had this.
1792 SourceLocation EqualLoc = NewArg.get()->getLocStart();
1793 SetParamDefaultArgument(NewParm, NewArg.get(), EqualLoc);
1796 // FIXME: if we non-lazily instantiated non-dependent default args for
1797 // non-dependent parameter types we could remove a bunch of duplicate
1798 // conversion warnings for such arguments.
1799 NewParm->setUninstantiatedDefaultArg(Arg);
1803 NewParm->setHasInheritedDefaultArg(OldParm->hasInheritedDefaultArg());
1805 if (OldParm->isParameterPack() && !NewParm->isParameterPack()) {
1806 // Add the new parameter to the instantiated parameter pack.
1807 CurrentInstantiationScope->InstantiatedLocalPackArg(OldParm, NewParm);
1809 // Introduce an Old -> New mapping
1810 CurrentInstantiationScope->InstantiatedLocal(OldParm, NewParm);
1813 // FIXME: OldParm may come from a FunctionProtoType, in which case CurContext
1814 // can be anything, is this right ?
1815 NewParm->setDeclContext(CurContext);
1817 NewParm->setScopeInfo(OldParm->getFunctionScopeDepth(),
1818 OldParm->getFunctionScopeIndex() + indexAdjustment);
1820 InstantiateAttrs(TemplateArgs, OldParm, NewParm);
1825 /// Substitute the given template arguments into the given set of
1826 /// parameters, producing the set of parameter types that would be generated
1827 /// from such a substitution.
1828 bool Sema::SubstParmTypes(
1829 SourceLocation Loc, ArrayRef<ParmVarDecl *> Params,
1830 const FunctionProtoType::ExtParameterInfo *ExtParamInfos,
1831 const MultiLevelTemplateArgumentList &TemplateArgs,
1832 SmallVectorImpl<QualType> &ParamTypes,
1833 SmallVectorImpl<ParmVarDecl *> *OutParams,
1834 ExtParameterInfoBuilder &ParamInfos) {
1835 assert(!CodeSynthesisContexts.empty() &&
1836 "Cannot perform an instantiation without some context on the "
1837 "instantiation stack");
1839 TemplateInstantiator Instantiator(*this, TemplateArgs, Loc,
1841 return Instantiator.TransformFunctionTypeParams(
1842 Loc, Params, nullptr, ExtParamInfos, ParamTypes, OutParams, ParamInfos);
1845 /// Perform substitution on the base class specifiers of the
1846 /// given class template specialization.
1848 /// Produces a diagnostic and returns true on error, returns false and
1849 /// attaches the instantiated base classes to the class template
1850 /// specialization if successful.
1852 Sema::SubstBaseSpecifiers(CXXRecordDecl *Instantiation,
1853 CXXRecordDecl *Pattern,
1854 const MultiLevelTemplateArgumentList &TemplateArgs) {
1855 bool Invalid = false;
1856 SmallVector<CXXBaseSpecifier*, 4> InstantiatedBases;
1857 for (const auto &Base : Pattern->bases()) {
1858 if (!Base.getType()->isDependentType()) {
1859 if (const CXXRecordDecl *RD = Base.getType()->getAsCXXRecordDecl()) {
1860 if (RD->isInvalidDecl())
1861 Instantiation->setInvalidDecl();
1863 InstantiatedBases.push_back(new (Context) CXXBaseSpecifier(Base));
1867 SourceLocation EllipsisLoc;
1868 TypeSourceInfo *BaseTypeLoc;
1869 if (Base.isPackExpansion()) {
1870 // This is a pack expansion. See whether we should expand it now, or
1871 // wait until later.
1872 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
1873 collectUnexpandedParameterPacks(Base.getTypeSourceInfo()->getTypeLoc(),
1875 bool ShouldExpand = false;
1876 bool RetainExpansion = false;
1877 Optional<unsigned> NumExpansions;
1878 if (CheckParameterPacksForExpansion(Base.getEllipsisLoc(),
1879 Base.getSourceRange(),
1881 TemplateArgs, ShouldExpand,
1888 // If we should expand this pack expansion now, do so.
1890 for (unsigned I = 0; I != *NumExpansions; ++I) {
1891 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, I);
1893 TypeSourceInfo *BaseTypeLoc = SubstType(Base.getTypeSourceInfo(),
1895 Base.getSourceRange().getBegin(),
1902 if (CXXBaseSpecifier *InstantiatedBase
1903 = CheckBaseSpecifier(Instantiation,
1904 Base.getSourceRange(),
1906 Base.getAccessSpecifierAsWritten(),
1909 InstantiatedBases.push_back(InstantiatedBase);
1917 // The resulting base specifier will (still) be a pack expansion.
1918 EllipsisLoc = Base.getEllipsisLoc();
1919 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, -1);
1920 BaseTypeLoc = SubstType(Base.getTypeSourceInfo(),
1922 Base.getSourceRange().getBegin(),
1925 BaseTypeLoc = SubstType(Base.getTypeSourceInfo(),
1927 Base.getSourceRange().getBegin(),
1936 if (CXXBaseSpecifier *InstantiatedBase
1937 = CheckBaseSpecifier(Instantiation,
1938 Base.getSourceRange(),
1940 Base.getAccessSpecifierAsWritten(),
1943 InstantiatedBases.push_back(InstantiatedBase);
1948 if (!Invalid && AttachBaseSpecifiers(Instantiation, InstantiatedBases))
1954 // Defined via #include from SemaTemplateInstantiateDecl.cpp
1957 Attr *instantiateTemplateAttribute(const Attr *At, ASTContext &C, Sema &S,
1958 const MultiLevelTemplateArgumentList &TemplateArgs);
1959 Attr *instantiateTemplateAttributeForDecl(
1960 const Attr *At, ASTContext &C, Sema &S,
1961 const MultiLevelTemplateArgumentList &TemplateArgs);
1965 /// Instantiate the definition of a class from a given pattern.
1967 /// \param PointOfInstantiation The point of instantiation within the
1970 /// \param Instantiation is the declaration whose definition is being
1971 /// instantiated. This will be either a class template specialization
1972 /// or a member class of a class template specialization.
1974 /// \param Pattern is the pattern from which the instantiation
1975 /// occurs. This will be either the declaration of a class template or
1976 /// the declaration of a member class of a class template.
1978 /// \param TemplateArgs The template arguments to be substituted into
1981 /// \param TSK the kind of implicit or explicit instantiation to perform.
1983 /// \param Complain whether to complain if the class cannot be instantiated due
1984 /// to the lack of a definition.
1986 /// \returns true if an error occurred, false otherwise.
1988 Sema::InstantiateClass(SourceLocation PointOfInstantiation,
1989 CXXRecordDecl *Instantiation, CXXRecordDecl *Pattern,
1990 const MultiLevelTemplateArgumentList &TemplateArgs,
1991 TemplateSpecializationKind TSK,
1993 CXXRecordDecl *PatternDef
1994 = cast_or_null<CXXRecordDecl>(Pattern->getDefinition());
1995 if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Instantiation,
1996 Instantiation->getInstantiatedFromMemberClass(),
1997 Pattern, PatternDef, TSK, Complain))
1999 Pattern = PatternDef;
2001 // Record the point of instantiation.
2002 if (MemberSpecializationInfo *MSInfo
2003 = Instantiation->getMemberSpecializationInfo()) {
2004 MSInfo->setTemplateSpecializationKind(TSK);
2005 MSInfo->setPointOfInstantiation(PointOfInstantiation);
2006 } else if (ClassTemplateSpecializationDecl *Spec
2007 = dyn_cast<ClassTemplateSpecializationDecl>(Instantiation)) {
2008 Spec->setTemplateSpecializationKind(TSK);
2009 Spec->setPointOfInstantiation(PointOfInstantiation);
2012 InstantiatingTemplate Inst(*this, PointOfInstantiation, Instantiation);
2013 if (Inst.isInvalid())
2015 assert(!Inst.isAlreadyInstantiating() && "should have been caught by caller");
2016 PrettyDeclStackTraceEntry CrashInfo(Context, Instantiation, SourceLocation(),
2017 "instantiating class definition");
2019 // Enter the scope of this instantiation. We don't use
2020 // PushDeclContext because we don't have a scope.
2021 ContextRAII SavedContext(*this, Instantiation);
2022 EnterExpressionEvaluationContext EvalContext(
2023 *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
2025 // If this is an instantiation of a local class, merge this local
2026 // instantiation scope with the enclosing scope. Otherwise, every
2027 // instantiation of a class has its own local instantiation scope.
2028 bool MergeWithParentScope = !Instantiation->isDefinedOutsideFunctionOrMethod();
2029 LocalInstantiationScope Scope(*this, MergeWithParentScope);
2031 // Some class state isn't processed immediately but delayed till class
2032 // instantiation completes. We may not be ready to handle any delayed state
2033 // already on the stack as it might correspond to a different class, so save
2034 // it now and put it back later.
2035 SavePendingParsedClassStateRAII SavedPendingParsedClassState(*this);
2037 // Pull attributes from the pattern onto the instantiation.
2038 InstantiateAttrs(TemplateArgs, Pattern, Instantiation);
2040 // Start the definition of this instantiation.
2041 Instantiation->startDefinition();
2043 // The instantiation is visible here, even if it was first declared in an
2044 // unimported module.
2045 Instantiation->setVisibleDespiteOwningModule();
2047 // FIXME: This loses the as-written tag kind for an explicit instantiation.
2048 Instantiation->setTagKind(Pattern->getTagKind());
2050 // Do substitution on the base class specifiers.
2051 if (SubstBaseSpecifiers(Instantiation, Pattern, TemplateArgs))
2052 Instantiation->setInvalidDecl();
2054 TemplateDeclInstantiator Instantiator(*this, Instantiation, TemplateArgs);
2055 SmallVector<Decl*, 4> Fields;
2056 // Delay instantiation of late parsed attributes.
2057 LateInstantiatedAttrVec LateAttrs;
2058 Instantiator.enableLateAttributeInstantiation(&LateAttrs);
2060 for (auto *Member : Pattern->decls()) {
2061 // Don't instantiate members not belonging in this semantic context.
2064 // template <int i> class A {
2068 // 'class B' has the template as lexical context but semantically it is
2069 // introduced in namespace scope.
2070 if (Member->getDeclContext() != Pattern)
2073 // BlockDecls can appear in a default-member-initializer. They must be the
2074 // child of a BlockExpr, so we only know how to instantiate them from there.
2075 if (isa<BlockDecl>(Member))
2078 if (Member->isInvalidDecl()) {
2079 Instantiation->setInvalidDecl();
2083 Decl *NewMember = Instantiator.Visit(Member);
2085 if (FieldDecl *Field = dyn_cast<FieldDecl>(NewMember)) {
2086 Fields.push_back(Field);
2087 } else if (EnumDecl *Enum = dyn_cast<EnumDecl>(NewMember)) {
2088 // C++11 [temp.inst]p1: The implicit instantiation of a class template
2089 // specialization causes the implicit instantiation of the definitions
2090 // of unscoped member enumerations.
2091 // Record a point of instantiation for this implicit instantiation.
2092 if (TSK == TSK_ImplicitInstantiation && !Enum->isScoped() &&
2093 Enum->isCompleteDefinition()) {
2094 MemberSpecializationInfo *MSInfo =Enum->getMemberSpecializationInfo();
2095 assert(MSInfo && "no spec info for member enum specialization");
2096 MSInfo->setTemplateSpecializationKind(TSK_ImplicitInstantiation);
2097 MSInfo->setPointOfInstantiation(PointOfInstantiation);
2099 } else if (StaticAssertDecl *SA = dyn_cast<StaticAssertDecl>(NewMember)) {
2100 if (SA->isFailed()) {
2101 // A static_assert failed. Bail out; instantiating this
2102 // class is probably not meaningful.
2103 Instantiation->setInvalidDecl();
2108 if (NewMember->isInvalidDecl())
2109 Instantiation->setInvalidDecl();
2111 // FIXME: Eventually, a NULL return will mean that one of the
2112 // instantiations was a semantic disaster, and we'll want to mark the
2113 // declaration invalid.
2114 // For now, we expect to skip some members that we can't yet handle.
2118 // Finish checking fields.
2119 ActOnFields(nullptr, Instantiation->getLocation(), Instantiation, Fields,
2120 SourceLocation(), SourceLocation(), ParsedAttributesView());
2121 CheckCompletedCXXClass(Instantiation);
2123 // Default arguments are parsed, if not instantiated. We can go instantiate
2124 // default arg exprs for default constructors if necessary now.
2125 ActOnFinishCXXNonNestedClass(Instantiation);
2127 // Instantiate late parsed attributes, and attach them to their decls.
2128 // See Sema::InstantiateAttrs
2129 for (LateInstantiatedAttrVec::iterator I = LateAttrs.begin(),
2130 E = LateAttrs.end(); I != E; ++I) {
2131 assert(CurrentInstantiationScope == Instantiator.getStartingScope());
2132 CurrentInstantiationScope = I->Scope;
2134 // Allow 'this' within late-parsed attributes.
2135 NamedDecl *ND = dyn_cast<NamedDecl>(I->NewDecl);
2136 CXXRecordDecl *ThisContext =
2137 dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext());
2138 CXXThisScopeRAII ThisScope(*this, ThisContext, /*TypeQuals*/0,
2139 ND && ND->isCXXInstanceMember());
2142 instantiateTemplateAttribute(I->TmplAttr, Context, *this, TemplateArgs);
2143 I->NewDecl->addAttr(NewAttr);
2144 LocalInstantiationScope::deleteScopes(I->Scope,
2145 Instantiator.getStartingScope());
2147 Instantiator.disableLateAttributeInstantiation();
2150 ActOnFinishDelayedMemberInitializers(Instantiation);
2152 // FIXME: We should do something similar for explicit instantiations so they
2153 // end up in the right module.
2154 if (TSK == TSK_ImplicitInstantiation) {
2155 Instantiation->setLocation(Pattern->getLocation());
2156 Instantiation->setLocStart(Pattern->getInnerLocStart());
2157 Instantiation->setBraceRange(Pattern->getBraceRange());
2160 if (!Instantiation->isInvalidDecl()) {
2161 // Perform any dependent diagnostics from the pattern.
2162 PerformDependentDiagnostics(Pattern, TemplateArgs);
2164 // Instantiate any out-of-line class template partial
2165 // specializations now.
2166 for (TemplateDeclInstantiator::delayed_partial_spec_iterator
2167 P = Instantiator.delayed_partial_spec_begin(),
2168 PEnd = Instantiator.delayed_partial_spec_end();
2170 if (!Instantiator.InstantiateClassTemplatePartialSpecialization(
2171 P->first, P->second)) {
2172 Instantiation->setInvalidDecl();
2177 // Instantiate any out-of-line variable template partial
2178 // specializations now.
2179 for (TemplateDeclInstantiator::delayed_var_partial_spec_iterator
2180 P = Instantiator.delayed_var_partial_spec_begin(),
2181 PEnd = Instantiator.delayed_var_partial_spec_end();
2183 if (!Instantiator.InstantiateVarTemplatePartialSpecialization(
2184 P->first, P->second)) {
2185 Instantiation->setInvalidDecl();
2191 // Exit the scope of this instantiation.
2194 if (!Instantiation->isInvalidDecl()) {
2195 Consumer.HandleTagDeclDefinition(Instantiation);
2197 // Always emit the vtable for an explicit instantiation definition
2198 // of a polymorphic class template specialization.
2199 if (TSK == TSK_ExplicitInstantiationDefinition)
2200 MarkVTableUsed(PointOfInstantiation, Instantiation, true);
2203 return Instantiation->isInvalidDecl();
2206 /// Instantiate the definition of an enum from a given pattern.
2208 /// \param PointOfInstantiation The point of instantiation within the
2210 /// \param Instantiation is the declaration whose definition is being
2211 /// instantiated. This will be a member enumeration of a class
2212 /// temploid specialization, or a local enumeration within a
2213 /// function temploid specialization.
2214 /// \param Pattern The templated declaration from which the instantiation
2216 /// \param TemplateArgs The template arguments to be substituted into
2218 /// \param TSK The kind of implicit or explicit instantiation to perform.
2220 /// \return \c true if an error occurred, \c false otherwise.
2221 bool Sema::InstantiateEnum(SourceLocation PointOfInstantiation,
2222 EnumDecl *Instantiation, EnumDecl *Pattern,
2223 const MultiLevelTemplateArgumentList &TemplateArgs,
2224 TemplateSpecializationKind TSK) {
2225 EnumDecl *PatternDef = Pattern->getDefinition();
2226 if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Instantiation,
2227 Instantiation->getInstantiatedFromMemberEnum(),
2228 Pattern, PatternDef, TSK,/*Complain*/true))
2230 Pattern = PatternDef;
2232 // Record the point of instantiation.
2233 if (MemberSpecializationInfo *MSInfo
2234 = Instantiation->getMemberSpecializationInfo()) {
2235 MSInfo->setTemplateSpecializationKind(TSK);
2236 MSInfo->setPointOfInstantiation(PointOfInstantiation);
2239 InstantiatingTemplate Inst(*this, PointOfInstantiation, Instantiation);
2240 if (Inst.isInvalid())
2242 if (Inst.isAlreadyInstantiating())
2244 PrettyDeclStackTraceEntry CrashInfo(Context, Instantiation, SourceLocation(),
2245 "instantiating enum definition");
2247 // The instantiation is visible here, even if it was first declared in an
2248 // unimported module.
2249 Instantiation->setVisibleDespiteOwningModule();
2251 // Enter the scope of this instantiation. We don't use
2252 // PushDeclContext because we don't have a scope.
2253 ContextRAII SavedContext(*this, Instantiation);
2254 EnterExpressionEvaluationContext EvalContext(
2255 *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
2257 LocalInstantiationScope Scope(*this, /*MergeWithParentScope*/true);
2259 // Pull attributes from the pattern onto the instantiation.
2260 InstantiateAttrs(TemplateArgs, Pattern, Instantiation);
2262 TemplateDeclInstantiator Instantiator(*this, Instantiation, TemplateArgs);
2263 Instantiator.InstantiateEnumDefinition(Instantiation, Pattern);
2265 // Exit the scope of this instantiation.
2268 return Instantiation->isInvalidDecl();
2272 /// Instantiate the definition of a field from the given pattern.
2274 /// \param PointOfInstantiation The point of instantiation within the
2276 /// \param Instantiation is the declaration whose definition is being
2277 /// instantiated. This will be a class of a class temploid
2278 /// specialization, or a local enumeration within a function temploid
2280 /// \param Pattern The templated declaration from which the instantiation
2282 /// \param TemplateArgs The template arguments to be substituted into
2285 /// \return \c true if an error occurred, \c false otherwise.
2286 bool Sema::InstantiateInClassInitializer(
2287 SourceLocation PointOfInstantiation, FieldDecl *Instantiation,
2288 FieldDecl *Pattern, const MultiLevelTemplateArgumentList &TemplateArgs) {
2289 // If there is no initializer, we don't need to do anything.
2290 if (!Pattern->hasInClassInitializer())
2293 assert(Instantiation->getInClassInitStyle() ==
2294 Pattern->getInClassInitStyle() &&
2295 "pattern and instantiation disagree about init style");
2297 // Error out if we haven't parsed the initializer of the pattern yet because
2298 // we are waiting for the closing brace of the outer class.
2299 Expr *OldInit = Pattern->getInClassInitializer();
2301 RecordDecl *PatternRD = Pattern->getParent();
2302 RecordDecl *OutermostClass = PatternRD->getOuterLexicalRecordContext();
2303 Diag(PointOfInstantiation,
2304 diag::err_in_class_initializer_not_yet_parsed)
2305 << OutermostClass << Pattern;
2306 Diag(Pattern->getLocEnd(), diag::note_in_class_initializer_not_yet_parsed);
2307 Instantiation->setInvalidDecl();
2311 InstantiatingTemplate Inst(*this, PointOfInstantiation, Instantiation);
2312 if (Inst.isInvalid())
2314 if (Inst.isAlreadyInstantiating()) {
2315 // Error out if we hit an instantiation cycle for this initializer.
2316 Diag(PointOfInstantiation, diag::err_in_class_initializer_cycle)
2320 PrettyDeclStackTraceEntry CrashInfo(Context, Instantiation, SourceLocation(),
2321 "instantiating default member init");
2323 // Enter the scope of this instantiation. We don't use PushDeclContext because
2324 // we don't have a scope.
2325 ContextRAII SavedContext(*this, Instantiation->getParent());
2326 EnterExpressionEvaluationContext EvalContext(
2327 *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
2329 LocalInstantiationScope Scope(*this, true);
2331 // Instantiate the initializer.
2332 ActOnStartCXXInClassMemberInitializer();
2333 CXXThisScopeRAII ThisScope(*this, Instantiation->getParent(), /*TypeQuals=*/0);
2335 ExprResult NewInit = SubstInitializer(OldInit, TemplateArgs,
2336 /*CXXDirectInit=*/false);
2337 Expr *Init = NewInit.get();
2338 assert((!Init || !isa<ParenListExpr>(Init)) && "call-style init in class");
2339 ActOnFinishCXXInClassMemberInitializer(
2340 Instantiation, Init ? Init->getLocStart() : SourceLocation(), Init);
2342 if (auto *L = getASTMutationListener())
2343 L->DefaultMemberInitializerInstantiated(Instantiation);
2345 // Return true if the in-class initializer is still missing.
2346 return !Instantiation->getInClassInitializer();
2350 /// A partial specialization whose template arguments have matched
2351 /// a given template-id.
2352 struct PartialSpecMatchResult {
2353 ClassTemplatePartialSpecializationDecl *Partial;
2354 TemplateArgumentList *Args;
2358 bool Sema::usesPartialOrExplicitSpecialization(
2359 SourceLocation Loc, ClassTemplateSpecializationDecl *ClassTemplateSpec) {
2360 if (ClassTemplateSpec->getTemplateSpecializationKind() ==
2361 TSK_ExplicitSpecialization)
2364 SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
2365 ClassTemplateSpec->getSpecializedTemplate()
2366 ->getPartialSpecializations(PartialSpecs);
2367 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) {
2368 TemplateDeductionInfo Info(Loc);
2369 if (!DeduceTemplateArguments(PartialSpecs[I],
2370 ClassTemplateSpec->getTemplateArgs(), Info))
2377 /// Get the instantiation pattern to use to instantiate the definition of a
2378 /// given ClassTemplateSpecializationDecl (either the pattern of the primary
2379 /// template or of a partial specialization).
2380 static CXXRecordDecl *
2381 getPatternForClassTemplateSpecialization(
2382 Sema &S, SourceLocation PointOfInstantiation,
2383 ClassTemplateSpecializationDecl *ClassTemplateSpec,
2384 TemplateSpecializationKind TSK, bool Complain) {
2385 Sema::InstantiatingTemplate Inst(S, PointOfInstantiation, ClassTemplateSpec);
2386 if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
2389 llvm::PointerUnion<ClassTemplateDecl *,
2390 ClassTemplatePartialSpecializationDecl *>
2391 Specialized = ClassTemplateSpec->getSpecializedTemplateOrPartial();
2392 if (!Specialized.is<ClassTemplatePartialSpecializationDecl *>()) {
2393 // Find best matching specialization.
2394 ClassTemplateDecl *Template = ClassTemplateSpec->getSpecializedTemplate();
2396 // C++ [temp.class.spec.match]p1:
2397 // When a class template is used in a context that requires an
2398 // instantiation of the class, it is necessary to determine
2399 // whether the instantiation is to be generated using the primary
2400 // template or one of the partial specializations. This is done by
2401 // matching the template arguments of the class template
2402 // specialization with the template argument lists of the partial
2404 typedef PartialSpecMatchResult MatchResult;
2405 SmallVector<MatchResult, 4> Matched;
2406 SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
2407 Template->getPartialSpecializations(PartialSpecs);
2408 TemplateSpecCandidateSet FailedCandidates(PointOfInstantiation);
2409 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) {
2410 ClassTemplatePartialSpecializationDecl *Partial = PartialSpecs[I];
2411 TemplateDeductionInfo Info(FailedCandidates.getLocation());
2412 if (Sema::TemplateDeductionResult Result = S.DeduceTemplateArguments(
2413 Partial, ClassTemplateSpec->getTemplateArgs(), Info)) {
2414 // Store the failed-deduction information for use in diagnostics, later.
2415 // TODO: Actually use the failed-deduction info?
2416 FailedCandidates.addCandidate().set(
2417 DeclAccessPair::make(Template, AS_public), Partial,
2418 MakeDeductionFailureInfo(S.Context, Result, Info));
2421 Matched.push_back(PartialSpecMatchResult());
2422 Matched.back().Partial = Partial;
2423 Matched.back().Args = Info.take();
2427 // If we're dealing with a member template where the template parameters
2428 // have been instantiated, this provides the original template parameters
2429 // from which the member template's parameters were instantiated.
2431 if (Matched.size() >= 1) {
2432 SmallVectorImpl<MatchResult>::iterator Best = Matched.begin();
2433 if (Matched.size() == 1) {
2434 // -- If exactly one matching specialization is found, the
2435 // instantiation is generated from that specialization.
2436 // We don't need to do anything for this.
2438 // -- If more than one matching specialization is found, the
2439 // partial order rules (14.5.4.2) are used to determine
2440 // whether one of the specializations is more specialized
2441 // than the others. If none of the specializations is more
2442 // specialized than all of the other matching
2443 // specializations, then the use of the class template is
2444 // ambiguous and the program is ill-formed.
2445 for (SmallVectorImpl<MatchResult>::iterator P = Best + 1,
2446 PEnd = Matched.end();
2448 if (S.getMoreSpecializedPartialSpecialization(
2449 P->Partial, Best->Partial, PointOfInstantiation) ==
2454 // Determine if the best partial specialization is more specialized than
2456 bool Ambiguous = false;
2457 for (SmallVectorImpl<MatchResult>::iterator P = Matched.begin(),
2458 PEnd = Matched.end();
2460 if (P != Best && S.getMoreSpecializedPartialSpecialization(
2461 P->Partial, Best->Partial,
2462 PointOfInstantiation) != Best->Partial) {
2469 // Partial ordering did not produce a clear winner. Complain.
2471 ClassTemplateSpec->setInvalidDecl();
2472 S.Diag(PointOfInstantiation,
2473 diag::err_partial_spec_ordering_ambiguous)
2474 << ClassTemplateSpec;
2476 // Print the matching partial specializations.
2477 for (SmallVectorImpl<MatchResult>::iterator P = Matched.begin(),
2478 PEnd = Matched.end();
2480 S.Diag(P->Partial->getLocation(), diag::note_partial_spec_match)
2481 << S.getTemplateArgumentBindingsText(
2482 P->Partial->getTemplateParameters(), *P->Args);
2488 ClassTemplateSpec->setInstantiationOf(Best->Partial, Best->Args);
2490 // -- If no matches are found, the instantiation is generated
2491 // from the primary template.
2495 CXXRecordDecl *Pattern = nullptr;
2496 Specialized = ClassTemplateSpec->getSpecializedTemplateOrPartial();
2497 if (auto *PartialSpec =
2498 Specialized.dyn_cast<ClassTemplatePartialSpecializationDecl *>()) {
2499 // Instantiate using the best class template partial specialization.
2500 while (PartialSpec->getInstantiatedFromMember()) {
2501 // If we've found an explicit specialization of this class template,
2502 // stop here and use that as the pattern.
2503 if (PartialSpec->isMemberSpecialization())
2506 PartialSpec = PartialSpec->getInstantiatedFromMember();
2508 Pattern = PartialSpec;
2510 ClassTemplateDecl *Template = ClassTemplateSpec->getSpecializedTemplate();
2511 while (Template->getInstantiatedFromMemberTemplate()) {
2512 // If we've found an explicit specialization of this class template,
2513 // stop here and use that as the pattern.
2514 if (Template->isMemberSpecialization())
2517 Template = Template->getInstantiatedFromMemberTemplate();
2519 Pattern = Template->getTemplatedDecl();
2525 bool Sema::InstantiateClassTemplateSpecialization(
2526 SourceLocation PointOfInstantiation,
2527 ClassTemplateSpecializationDecl *ClassTemplateSpec,
2528 TemplateSpecializationKind TSK, bool Complain) {
2529 // Perform the actual instantiation on the canonical declaration.
2530 ClassTemplateSpec = cast<ClassTemplateSpecializationDecl>(
2531 ClassTemplateSpec->getCanonicalDecl());
2532 if (ClassTemplateSpec->isInvalidDecl())
2535 CXXRecordDecl *Pattern = getPatternForClassTemplateSpecialization(
2536 *this, PointOfInstantiation, ClassTemplateSpec, TSK, Complain);
2540 return InstantiateClass(PointOfInstantiation, ClassTemplateSpec, Pattern,
2541 getTemplateInstantiationArgs(ClassTemplateSpec), TSK,
2545 /// Instantiates the definitions of all of the member
2546 /// of the given class, which is an instantiation of a class template
2547 /// or a member class of a template.
2549 Sema::InstantiateClassMembers(SourceLocation PointOfInstantiation,
2550 CXXRecordDecl *Instantiation,
2551 const MultiLevelTemplateArgumentList &TemplateArgs,
2552 TemplateSpecializationKind TSK) {
2553 // FIXME: We need to notify the ASTMutationListener that we did all of these
2554 // things, in case we have an explicit instantiation definition in a PCM, a
2555 // module, or preamble, and the declaration is in an imported AST.
2557 (TSK == TSK_ExplicitInstantiationDefinition ||
2558 TSK == TSK_ExplicitInstantiationDeclaration ||
2559 (TSK == TSK_ImplicitInstantiation && Instantiation->isLocalClass())) &&
2560 "Unexpected template specialization kind!");
2561 for (auto *D : Instantiation->decls()) {
2562 bool SuppressNew = false;
2563 if (auto *Function = dyn_cast<FunctionDecl>(D)) {
2564 if (FunctionDecl *Pattern
2565 = Function->getInstantiatedFromMemberFunction()) {
2566 MemberSpecializationInfo *MSInfo
2567 = Function->getMemberSpecializationInfo();
2568 assert(MSInfo && "No member specialization information?");
2569 if (MSInfo->getTemplateSpecializationKind()
2570 == TSK_ExplicitSpecialization)
2573 if (CheckSpecializationInstantiationRedecl(PointOfInstantiation, TSK,
2575 MSInfo->getTemplateSpecializationKind(),
2576 MSInfo->getPointOfInstantiation(),
2581 // C++11 [temp.explicit]p8:
2582 // An explicit instantiation definition that names a class template
2583 // specialization explicitly instantiates the class template
2584 // specialization and is only an explicit instantiation definition
2585 // of members whose definition is visible at the point of
2587 if (TSK == TSK_ExplicitInstantiationDefinition && !Pattern->isDefined())
2590 Function->setTemplateSpecializationKind(TSK, PointOfInstantiation);
2592 if (Function->isDefined()) {
2593 // Let the ASTConsumer know that this function has been explicitly
2594 // instantiated now, and its linkage might have changed.
2595 Consumer.HandleTopLevelDecl(DeclGroupRef(Function));
2596 } else if (TSK == TSK_ExplicitInstantiationDefinition) {
2597 InstantiateFunctionDefinition(PointOfInstantiation, Function);
2598 } else if (TSK == TSK_ImplicitInstantiation) {
2599 PendingLocalImplicitInstantiations.push_back(
2600 std::make_pair(Function, PointOfInstantiation));
2603 } else if (auto *Var = dyn_cast<VarDecl>(D)) {
2604 if (isa<VarTemplateSpecializationDecl>(Var))
2607 if (Var->isStaticDataMember()) {
2608 MemberSpecializationInfo *MSInfo = Var->getMemberSpecializationInfo();
2609 assert(MSInfo && "No member specialization information?");
2610 if (MSInfo->getTemplateSpecializationKind()
2611 == TSK_ExplicitSpecialization)
2614 if (CheckSpecializationInstantiationRedecl(PointOfInstantiation, TSK,
2616 MSInfo->getTemplateSpecializationKind(),
2617 MSInfo->getPointOfInstantiation(),
2622 if (TSK == TSK_ExplicitInstantiationDefinition) {
2623 // C++0x [temp.explicit]p8:
2624 // An explicit instantiation definition that names a class template
2625 // specialization explicitly instantiates the class template
2626 // specialization and is only an explicit instantiation definition
2627 // of members whose definition is visible at the point of
2629 if (!Var->getInstantiatedFromStaticDataMember()->getDefinition())
2632 Var->setTemplateSpecializationKind(TSK, PointOfInstantiation);
2633 InstantiateVariableDefinition(PointOfInstantiation, Var);
2635 Var->setTemplateSpecializationKind(TSK, PointOfInstantiation);
2638 } else if (auto *Record = dyn_cast<CXXRecordDecl>(D)) {
2639 // Always skip the injected-class-name, along with any
2640 // redeclarations of nested classes, since both would cause us
2641 // to try to instantiate the members of a class twice.
2642 // Skip closure types; they'll get instantiated when we instantiate
2643 // the corresponding lambda-expression.
2644 if (Record->isInjectedClassName() || Record->getPreviousDecl() ||
2648 MemberSpecializationInfo *MSInfo = Record->getMemberSpecializationInfo();
2649 assert(MSInfo && "No member specialization information?");
2651 if (MSInfo->getTemplateSpecializationKind()
2652 == TSK_ExplicitSpecialization)
2655 if ((Context.getTargetInfo().getCXXABI().isMicrosoft() ||
2656 Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment()) &&
2657 TSK == TSK_ExplicitInstantiationDeclaration) {
2658 // In MSVC and Windows Itanium mode, explicit instantiation decl of the
2659 // outer class doesn't affect the inner class.
2663 if (CheckSpecializationInstantiationRedecl(PointOfInstantiation, TSK,
2665 MSInfo->getTemplateSpecializationKind(),
2666 MSInfo->getPointOfInstantiation(),
2671 CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass();
2672 assert(Pattern && "Missing instantiated-from-template information");
2674 if (!Record->getDefinition()) {
2675 if (!Pattern->getDefinition()) {
2676 // C++0x [temp.explicit]p8:
2677 // An explicit instantiation definition that names a class template
2678 // specialization explicitly instantiates the class template
2679 // specialization and is only an explicit instantiation definition
2680 // of members whose definition is visible at the point of
2682 if (TSK == TSK_ExplicitInstantiationDeclaration) {
2683 MSInfo->setTemplateSpecializationKind(TSK);
2684 MSInfo->setPointOfInstantiation(PointOfInstantiation);
2690 InstantiateClass(PointOfInstantiation, Record, Pattern,
2694 if (TSK == TSK_ExplicitInstantiationDefinition &&
2695 Record->getTemplateSpecializationKind() ==
2696 TSK_ExplicitInstantiationDeclaration) {
2697 Record->setTemplateSpecializationKind(TSK);
2698 MarkVTableUsed(PointOfInstantiation, Record, true);
2702 Pattern = cast_or_null<CXXRecordDecl>(Record->getDefinition());
2704 InstantiateClassMembers(PointOfInstantiation, Pattern, TemplateArgs,
2706 } else if (auto *Enum = dyn_cast<EnumDecl>(D)) {
2707 MemberSpecializationInfo *MSInfo = Enum->getMemberSpecializationInfo();
2708 assert(MSInfo && "No member specialization information?");
2710 if (MSInfo->getTemplateSpecializationKind()
2711 == TSK_ExplicitSpecialization)
2714 if (CheckSpecializationInstantiationRedecl(
2715 PointOfInstantiation, TSK, Enum,
2716 MSInfo->getTemplateSpecializationKind(),
2717 MSInfo->getPointOfInstantiation(), SuppressNew) ||
2721 if (Enum->getDefinition())
2724 EnumDecl *Pattern = Enum->getTemplateInstantiationPattern();
2725 assert(Pattern && "Missing instantiated-from-template information");
2727 if (TSK == TSK_ExplicitInstantiationDefinition) {
2728 if (!Pattern->getDefinition())
2731 InstantiateEnum(PointOfInstantiation, Enum, Pattern, TemplateArgs, TSK);
2733 MSInfo->setTemplateSpecializationKind(TSK);
2734 MSInfo->setPointOfInstantiation(PointOfInstantiation);
2736 } else if (auto *Field = dyn_cast<FieldDecl>(D)) {
2737 // No need to instantiate in-class initializers during explicit
2739 if (Field->hasInClassInitializer() && TSK == TSK_ImplicitInstantiation) {
2740 CXXRecordDecl *ClassPattern =
2741 Instantiation->getTemplateInstantiationPattern();
2742 DeclContext::lookup_result Lookup =
2743 ClassPattern->lookup(Field->getDeclName());
2744 FieldDecl *Pattern = cast<FieldDecl>(Lookup.front());
2745 InstantiateInClassInitializer(PointOfInstantiation, Field, Pattern,
2752 /// Instantiate the definitions of all of the members of the
2753 /// given class template specialization, which was named as part of an
2754 /// explicit instantiation.
2756 Sema::InstantiateClassTemplateSpecializationMembers(
2757 SourceLocation PointOfInstantiation,
2758 ClassTemplateSpecializationDecl *ClassTemplateSpec,
2759 TemplateSpecializationKind TSK) {
2760 // C++0x [temp.explicit]p7:
2761 // An explicit instantiation that names a class template
2762 // specialization is an explicit instantion of the same kind
2763 // (declaration or definition) of each of its members (not
2764 // including members inherited from base classes) that has not
2765 // been previously explicitly specialized in the translation unit
2766 // containing the explicit instantiation, except as described
2768 InstantiateClassMembers(PointOfInstantiation, ClassTemplateSpec,
2769 getTemplateInstantiationArgs(ClassTemplateSpec),
2774 Sema::SubstStmt(Stmt *S, const MultiLevelTemplateArgumentList &TemplateArgs) {
2778 TemplateInstantiator Instantiator(*this, TemplateArgs,
2781 return Instantiator.TransformStmt(S);
2785 Sema::SubstExpr(Expr *E, const MultiLevelTemplateArgumentList &TemplateArgs) {
2789 TemplateInstantiator Instantiator(*this, TemplateArgs,
2792 return Instantiator.TransformExpr(E);
2795 ExprResult Sema::SubstInitializer(Expr *Init,
2796 const MultiLevelTemplateArgumentList &TemplateArgs,
2797 bool CXXDirectInit) {
2798 TemplateInstantiator Instantiator(*this, TemplateArgs,
2801 return Instantiator.TransformInitializer(Init, CXXDirectInit);
2804 bool Sema::SubstExprs(ArrayRef<Expr *> Exprs, bool IsCall,
2805 const MultiLevelTemplateArgumentList &TemplateArgs,
2806 SmallVectorImpl<Expr *> &Outputs) {
2810 TemplateInstantiator Instantiator(*this, TemplateArgs,
2813 return Instantiator.TransformExprs(Exprs.data(), Exprs.size(),
2817 NestedNameSpecifierLoc
2818 Sema::SubstNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS,
2819 const MultiLevelTemplateArgumentList &TemplateArgs) {
2821 return NestedNameSpecifierLoc();
2823 TemplateInstantiator Instantiator(*this, TemplateArgs, NNS.getBeginLoc(),
2825 return Instantiator.TransformNestedNameSpecifierLoc(NNS);
2828 /// Do template substitution on declaration name info.
2830 Sema::SubstDeclarationNameInfo(const DeclarationNameInfo &NameInfo,
2831 const MultiLevelTemplateArgumentList &TemplateArgs) {
2832 TemplateInstantiator Instantiator(*this, TemplateArgs, NameInfo.getLoc(),
2833 NameInfo.getName());
2834 return Instantiator.TransformDeclarationNameInfo(NameInfo);
2838 Sema::SubstTemplateName(NestedNameSpecifierLoc QualifierLoc,
2839 TemplateName Name, SourceLocation Loc,
2840 const MultiLevelTemplateArgumentList &TemplateArgs) {
2841 TemplateInstantiator Instantiator(*this, TemplateArgs, Loc,
2844 SS.Adopt(QualifierLoc);
2845 return Instantiator.TransformTemplateName(SS, Name, Loc);
2848 bool Sema::Subst(const TemplateArgumentLoc *Args, unsigned NumArgs,
2849 TemplateArgumentListInfo &Result,
2850 const MultiLevelTemplateArgumentList &TemplateArgs) {
2851 TemplateInstantiator Instantiator(*this, TemplateArgs, SourceLocation(),
2854 return Instantiator.TransformTemplateArguments(Args, NumArgs, Result);
2857 static const Decl *getCanonicalParmVarDecl(const Decl *D) {
2858 // When storing ParmVarDecls in the local instantiation scope, we always
2859 // want to use the ParmVarDecl from the canonical function declaration,
2860 // since the map is then valid for any redeclaration or definition of that
2862 if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(D)) {
2863 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(PV->getDeclContext())) {
2864 unsigned i = PV->getFunctionScopeIndex();
2865 // This parameter might be from a freestanding function type within the
2866 // function and isn't necessarily referring to one of FD's parameters.
2867 if (FD->getParamDecl(i) == PV)
2868 return FD->getCanonicalDecl()->getParamDecl(i);
2875 llvm::PointerUnion<Decl *, LocalInstantiationScope::DeclArgumentPack *> *
2876 LocalInstantiationScope::findInstantiationOf(const Decl *D) {
2877 D = getCanonicalParmVarDecl(D);
2878 for (LocalInstantiationScope *Current = this; Current;
2879 Current = Current->Outer) {
2881 // Check if we found something within this scope.
2882 const Decl *CheckD = D;
2884 LocalDeclsMap::iterator Found = Current->LocalDecls.find(CheckD);
2885 if (Found != Current->LocalDecls.end())
2886 return &Found->second;
2888 // If this is a tag declaration, it's possible that we need to look for
2889 // a previous declaration.
2890 if (const TagDecl *Tag = dyn_cast<TagDecl>(CheckD))
2891 CheckD = Tag->getPreviousDecl();
2896 // If we aren't combined with our outer scope, we're done.
2897 if (!Current->CombineWithOuterScope)
2901 // If we're performing a partial substitution during template argument
2902 // deduction, we may not have values for template parameters yet.
2903 if (isa<NonTypeTemplateParmDecl>(D) || isa<TemplateTypeParmDecl>(D) ||
2904 isa<TemplateTemplateParmDecl>(D))
2907 // Local types referenced prior to definition may require instantiation.
2908 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D))
2909 if (RD->isLocalClass())
2912 // Enumeration types referenced prior to definition may appear as a result of
2914 if (isa<EnumDecl>(D))
2917 // If we didn't find the decl, then we either have a sema bug, or we have a
2918 // forward reference to a label declaration. Return null to indicate that
2919 // we have an uninstantiated label.
2920 assert(isa<LabelDecl>(D) && "declaration not instantiated in this scope");
2924 void LocalInstantiationScope::InstantiatedLocal(const Decl *D, Decl *Inst) {
2925 D = getCanonicalParmVarDecl(D);
2926 llvm::PointerUnion<Decl *, DeclArgumentPack *> &Stored = LocalDecls[D];
2927 if (Stored.isNull()) {
2929 // It should not be present in any surrounding scope either.
2930 LocalInstantiationScope *Current = this;
2931 while (Current->CombineWithOuterScope && Current->Outer) {
2932 Current = Current->Outer;
2933 assert(Current->LocalDecls.find(D) == Current->LocalDecls.end() &&
2934 "Instantiated local in inner and outer scopes");
2938 } else if (DeclArgumentPack *Pack = Stored.dyn_cast<DeclArgumentPack *>()) {
2939 Pack->push_back(cast<ParmVarDecl>(Inst));
2941 assert(Stored.get<Decl *>() == Inst && "Already instantiated this local");
2945 void LocalInstantiationScope::InstantiatedLocalPackArg(const Decl *D,
2946 ParmVarDecl *Inst) {
2947 D = getCanonicalParmVarDecl(D);
2948 DeclArgumentPack *Pack = LocalDecls[D].get<DeclArgumentPack *>();
2949 Pack->push_back(Inst);
2952 void LocalInstantiationScope::MakeInstantiatedLocalArgPack(const Decl *D) {
2954 // This should be the first time we've been told about this decl.
2955 for (LocalInstantiationScope *Current = this;
2956 Current && Current->CombineWithOuterScope; Current = Current->Outer)
2957 assert(Current->LocalDecls.find(D) == Current->LocalDecls.end() &&
2958 "Creating local pack after instantiation of local");
2961 D = getCanonicalParmVarDecl(D);
2962 llvm::PointerUnion<Decl *, DeclArgumentPack *> &Stored = LocalDecls[D];
2963 DeclArgumentPack *Pack = new DeclArgumentPack;
2965 ArgumentPacks.push_back(Pack);
2968 void LocalInstantiationScope::SetPartiallySubstitutedPack(NamedDecl *Pack,
2969 const TemplateArgument *ExplicitArgs,
2970 unsigned NumExplicitArgs) {
2971 assert((!PartiallySubstitutedPack || PartiallySubstitutedPack == Pack) &&
2972 "Already have a partially-substituted pack");
2973 assert((!PartiallySubstitutedPack
2974 || NumArgsInPartiallySubstitutedPack == NumExplicitArgs) &&
2975 "Wrong number of arguments in partially-substituted pack");
2976 PartiallySubstitutedPack = Pack;
2977 ArgsInPartiallySubstitutedPack = ExplicitArgs;
2978 NumArgsInPartiallySubstitutedPack = NumExplicitArgs;
2981 NamedDecl *LocalInstantiationScope::getPartiallySubstitutedPack(
2982 const TemplateArgument **ExplicitArgs,
2983 unsigned *NumExplicitArgs) const {
2985 *ExplicitArgs = nullptr;
2986 if (NumExplicitArgs)
2987 *NumExplicitArgs = 0;
2989 for (const LocalInstantiationScope *Current = this; Current;
2990 Current = Current->Outer) {
2991 if (Current->PartiallySubstitutedPack) {
2993 *ExplicitArgs = Current->ArgsInPartiallySubstitutedPack;
2994 if (NumExplicitArgs)
2995 *NumExplicitArgs = Current->NumArgsInPartiallySubstitutedPack;
2997 return Current->PartiallySubstitutedPack;
3000 if (!Current->CombineWithOuterScope)