1 //===------- SemaTemplateInstantiate.cpp - C++ Template Instantiation ------===/
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //===----------------------------------------------------------------------===/
7 //
8 // This file implements C++ template instantiation.
9 //
10 //===----------------------------------------------------------------------===/
11
12 #include "TreeTransform.h"
13 #include "clang/AST/ASTConsumer.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/ASTLambda.h"
16 #include "clang/AST/ASTMutationListener.h"
17 #include "clang/AST/DeclTemplate.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/AST/PrettyDeclStackTrace.h"
20 #include "clang/AST/TypeVisitor.h"
21 #include "clang/Basic/LangOptions.h"
22 #include "clang/Basic/Stack.h"
23 #include "clang/Basic/TargetInfo.h"
24 #include "clang/Sema/DeclSpec.h"
25 #include "clang/Sema/Initialization.h"
26 #include "clang/Sema/Lookup.h"
27 #include "clang/Sema/SemaConcept.h"
28 #include "clang/Sema/SemaInternal.h"
29 #include "clang/Sema/Template.h"
30 #include "clang/Sema/TemplateDeduction.h"
31 #include "clang/Sema/TemplateInstCallback.h"
32 #include "llvm/Support/TimeProfiler.h"
33
34 using namespace clang;
35 using namespace sema;
36
37 //===----------------------------------------------------------------------===/
38 // Template Instantiation Support
39 //===----------------------------------------------------------------------===/
40
41 /// Retrieve the template argument list(s) that should be used to
42 /// instantiate the definition of the given declaration.
43 ///
44 /// \param D the declaration for which we are computing template instantiation
45 /// arguments.
46 ///
47 /// \param Innermost if non-NULL, the innermost template argument list.
48 ///
49 /// \param RelativeToPrimary true if we should get the template
50 /// arguments relative to the primary template, even when we're
51 /// dealing with a specialization. This is only relevant for function
52 /// template specializations.
53 ///
54 /// \param Pattern If non-NULL, indicates the pattern from which we will be
55 /// instantiating the definition of the given declaration, \p D. This is
56 /// used to determine the proper set of template instantiation arguments for
57 /// friend function template specializations.
58 MultiLevelTemplateArgumentList
getTemplateInstantiationArgs(NamedDecl * D,const TemplateArgumentList * Innermost,bool RelativeToPrimary,const FunctionDecl * Pattern)59 Sema::getTemplateInstantiationArgs(NamedDecl *D,
60 const TemplateArgumentList *Innermost,
61 bool RelativeToPrimary,
62 const FunctionDecl *Pattern) {
63 // Accumulate the set of template argument lists in this structure.
64 MultiLevelTemplateArgumentList Result;
65
66 if (Innermost)
67 Result.addOuterTemplateArguments(Innermost);
68
69 DeclContext *Ctx = dyn_cast<DeclContext>(D);
70 if (!Ctx) {
71 Ctx = D->getDeclContext();
72
73 // Add template arguments from a variable template instantiation. For a
74 // class-scope explicit specialization, there are no template arguments
75 // at this level, but there may be enclosing template arguments.
76 VarTemplateSpecializationDecl *Spec =
77 dyn_cast<VarTemplateSpecializationDecl>(D);
78 if (Spec && !Spec->isClassScopeExplicitSpecialization()) {
79 // We're done when we hit an explicit specialization.
80 if (Spec->getSpecializationKind() == TSK_ExplicitSpecialization &&
81 !isa<VarTemplatePartialSpecializationDecl>(Spec))
82 return Result;
83
84 Result.addOuterTemplateArguments(&Spec->getTemplateInstantiationArgs());
85
86 // If this variable template specialization was instantiated from a
87 // specialized member that is a variable template, we're done.
88 assert(Spec->getSpecializedTemplate() && "No variable template?");
89 llvm::PointerUnion<VarTemplateDecl*,
90 VarTemplatePartialSpecializationDecl*> Specialized
91 = Spec->getSpecializedTemplateOrPartial();
92 if (VarTemplatePartialSpecializationDecl *Partial =
93 Specialized.dyn_cast<VarTemplatePartialSpecializationDecl *>()) {
94 if (Partial->isMemberSpecialization())
95 return Result;
96 } else {
97 VarTemplateDecl *Tmpl = Specialized.get<VarTemplateDecl *>();
98 if (Tmpl->isMemberSpecialization())
99 return Result;
100 }
101 }
102
103 // If we have a template template parameter with translation unit context,
104 // then we're performing substitution into a default template argument of
105 // this template template parameter before we've constructed the template
106 // that will own this template template parameter. In this case, we
107 // use empty template parameter lists for all of the outer templates
108 // to avoid performing any substitutions.
109 if (Ctx->isTranslationUnit()) {
110 if (TemplateTemplateParmDecl *TTP
111 = dyn_cast<TemplateTemplateParmDecl>(D)) {
112 for (unsigned I = 0, N = TTP->getDepth() + 1; I != N; ++I)
113 Result.addOuterTemplateArguments(None);
114 return Result;
115 }
116 }
117 }
118
119 while (!Ctx->isFileContext()) {
120 // Add template arguments from a class template instantiation.
121 ClassTemplateSpecializationDecl *Spec
122 = dyn_cast<ClassTemplateSpecializationDecl>(Ctx);
123 if (Spec && !Spec->isClassScopeExplicitSpecialization()) {
124 // We're done when we hit an explicit specialization.
125 if (Spec->getSpecializationKind() == TSK_ExplicitSpecialization &&
126 !isa<ClassTemplatePartialSpecializationDecl>(Spec))
127 break;
128
129 Result.addOuterTemplateArguments(&Spec->getTemplateInstantiationArgs());
130
131 // If this class template specialization was instantiated from a
132 // specialized member that is a class template, we're done.
133 assert(Spec->getSpecializedTemplate() && "No class template?");
134 if (Spec->getSpecializedTemplate()->isMemberSpecialization())
135 break;
136 }
137 // Add template arguments from a function template specialization.
138 else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Ctx)) {
139 if (!RelativeToPrimary &&
140 Function->getTemplateSpecializationKindForInstantiation() ==
141 TSK_ExplicitSpecialization)
142 break;
143
144 if (!RelativeToPrimary && Function->getTemplateSpecializationKind() ==
145 TSK_ExplicitSpecialization) {
146 // This is an implicit instantiation of an explicit specialization. We
147 // don't get any template arguments from this function but might get
148 // some from an enclosing template.
149 } else if (const TemplateArgumentList *TemplateArgs
150 = Function->getTemplateSpecializationArgs()) {
151 // Add the template arguments for this specialization.
152 Result.addOuterTemplateArguments(TemplateArgs);
153
154 // If this function was instantiated from a specialized member that is
155 // a function template, we're done.
156 assert(Function->getPrimaryTemplate() && "No function template?");
157 if (Function->getPrimaryTemplate()->isMemberSpecialization())
158 break;
159
160 // If this function is a generic lambda specialization, we are done.
161 if (isGenericLambdaCallOperatorOrStaticInvokerSpecialization(Function))
162 break;
163
164 } else if (FunctionTemplateDecl *FunTmpl
165 = Function->getDescribedFunctionTemplate()) {
166 // Add the "injected" template arguments.
167 Result.addOuterTemplateArguments(FunTmpl->getInjectedTemplateArgs());
168 }
169
170 // If this is a friend declaration and it declares an entity at
171 // namespace scope, take arguments from its lexical parent
172 // instead of its semantic parent, unless of course the pattern we're
173 // instantiating actually comes from the file's context!
174 if (Function->getFriendObjectKind() &&
175 Function->getDeclContext()->isFileContext() &&
176 (!Pattern || !Pattern->getLexicalDeclContext()->isFileContext())) {
177 Ctx = Function->getLexicalDeclContext();
178 RelativeToPrimary = false;
179 continue;
180 }
181 } else if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Ctx)) {
182 if (ClassTemplateDecl *ClassTemplate = Rec->getDescribedClassTemplate()) {
183 QualType T = ClassTemplate->getInjectedClassNameSpecialization();
184 const TemplateSpecializationType *TST =
185 cast<TemplateSpecializationType>(Context.getCanonicalType(T));
186 Result.addOuterTemplateArguments(
187 llvm::makeArrayRef(TST->getArgs(), TST->getNumArgs()));
188 if (ClassTemplate->isMemberSpecialization())
189 break;
190 }
191 }
192
193 Ctx = Ctx->getParent();
194 RelativeToPrimary = false;
195 }
196
197 return Result;
198 }
199
isInstantiationRecord() const200 bool Sema::CodeSynthesisContext::isInstantiationRecord() const {
201 switch (Kind) {
202 case TemplateInstantiation:
203 case ExceptionSpecInstantiation:
204 case DefaultTemplateArgumentInstantiation:
205 case DefaultFunctionArgumentInstantiation:
206 case ExplicitTemplateArgumentSubstitution:
207 case DeducedTemplateArgumentSubstitution:
208 case PriorTemplateArgumentSubstitution:
209 case ConstraintsCheck:
210 case NestedRequirementConstraintsCheck:
211 return true;
212
213 case RequirementInstantiation:
214 case DefaultTemplateArgumentChecking:
215 case DeclaringSpecialMember:
216 case DeclaringImplicitEqualityComparison:
217 case DefiningSynthesizedFunction:
218 case ExceptionSpecEvaluation:
219 case ConstraintSubstitution:
220 case ParameterMappingSubstitution:
221 case ConstraintNormalization:
222 case RewritingOperatorAsSpaceship:
223 case InitializingStructuredBinding:
224 case MarkingClassDllexported:
225 return false;
226
227 // This function should never be called when Kind's value is Memoization.
228 case Memoization:
229 break;
230 }
231
232 llvm_unreachable("Invalid SynthesisKind!");
233 }
234
InstantiatingTemplate(Sema & SemaRef,CodeSynthesisContext::SynthesisKind Kind,SourceLocation PointOfInstantiation,SourceRange InstantiationRange,Decl * Entity,NamedDecl * Template,ArrayRef<TemplateArgument> TemplateArgs,sema::TemplateDeductionInfo * DeductionInfo)235 Sema::InstantiatingTemplate::InstantiatingTemplate(
236 Sema &SemaRef, CodeSynthesisContext::SynthesisKind Kind,
237 SourceLocation PointOfInstantiation, SourceRange InstantiationRange,
238 Decl *Entity, NamedDecl *Template, ArrayRef<TemplateArgument> TemplateArgs,
239 sema::TemplateDeductionInfo *DeductionInfo)
240 : SemaRef(SemaRef) {
241 // Don't allow further instantiation if a fatal error and an uncompilable
242 // error have occurred. Any diagnostics we might have raised will not be
243 // visible, and we do not need to construct a correct AST.
244 if (SemaRef.Diags.hasFatalErrorOccurred() &&
245 SemaRef.hasUncompilableErrorOccurred()) {
246 Invalid = true;
247 return;
248 }
249 Invalid = CheckInstantiationDepth(PointOfInstantiation, InstantiationRange);
250 if (!Invalid) {
251 CodeSynthesisContext Inst;
252 Inst.Kind = Kind;
253 Inst.PointOfInstantiation = PointOfInstantiation;
254 Inst.Entity = Entity;
255 Inst.Template = Template;
256 Inst.TemplateArgs = TemplateArgs.data();
257 Inst.NumTemplateArgs = TemplateArgs.size();
258 Inst.DeductionInfo = DeductionInfo;
259 Inst.InstantiationRange = InstantiationRange;
260 SemaRef.pushCodeSynthesisContext(Inst);
261
262 AlreadyInstantiating = !Inst.Entity ? false :
263 !SemaRef.InstantiatingSpecializations
264 .insert({Inst.Entity->getCanonicalDecl(), Inst.Kind})
265 .second;
266 atTemplateBegin(SemaRef.TemplateInstCallbacks, SemaRef, Inst);
267 }
268 }
269
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,Decl * Entity,SourceRange InstantiationRange)270 Sema::InstantiatingTemplate::InstantiatingTemplate(
271 Sema &SemaRef, SourceLocation PointOfInstantiation, Decl *Entity,
272 SourceRange InstantiationRange)
273 : InstantiatingTemplate(SemaRef,
274 CodeSynthesisContext::TemplateInstantiation,
275 PointOfInstantiation, InstantiationRange, Entity) {}
276
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,FunctionDecl * Entity,ExceptionSpecification,SourceRange InstantiationRange)277 Sema::InstantiatingTemplate::InstantiatingTemplate(
278 Sema &SemaRef, SourceLocation PointOfInstantiation, FunctionDecl *Entity,
279 ExceptionSpecification, SourceRange InstantiationRange)
280 : InstantiatingTemplate(
281 SemaRef, CodeSynthesisContext::ExceptionSpecInstantiation,
282 PointOfInstantiation, InstantiationRange, Entity) {}
283
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,TemplateParameter Param,TemplateDecl * Template,ArrayRef<TemplateArgument> TemplateArgs,SourceRange InstantiationRange)284 Sema::InstantiatingTemplate::InstantiatingTemplate(
285 Sema &SemaRef, SourceLocation PointOfInstantiation, TemplateParameter Param,
286 TemplateDecl *Template, ArrayRef<TemplateArgument> TemplateArgs,
287 SourceRange InstantiationRange)
288 : InstantiatingTemplate(
289 SemaRef,
290 CodeSynthesisContext::DefaultTemplateArgumentInstantiation,
291 PointOfInstantiation, InstantiationRange, getAsNamedDecl(Param),
292 Template, TemplateArgs) {}
293
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,FunctionTemplateDecl * FunctionTemplate,ArrayRef<TemplateArgument> TemplateArgs,CodeSynthesisContext::SynthesisKind Kind,sema::TemplateDeductionInfo & DeductionInfo,SourceRange InstantiationRange)294 Sema::InstantiatingTemplate::InstantiatingTemplate(
295 Sema &SemaRef, SourceLocation PointOfInstantiation,
296 FunctionTemplateDecl *FunctionTemplate,
297 ArrayRef<TemplateArgument> TemplateArgs,
298 CodeSynthesisContext::SynthesisKind Kind,
299 sema::TemplateDeductionInfo &DeductionInfo, SourceRange InstantiationRange)
300 : InstantiatingTemplate(SemaRef, Kind, PointOfInstantiation,
301 InstantiationRange, FunctionTemplate, nullptr,
302 TemplateArgs, &DeductionInfo) {
303 assert(
304 Kind == CodeSynthesisContext::ExplicitTemplateArgumentSubstitution ||
305 Kind == CodeSynthesisContext::DeducedTemplateArgumentSubstitution);
306 }
307
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,TemplateDecl * Template,ArrayRef<TemplateArgument> TemplateArgs,sema::TemplateDeductionInfo & DeductionInfo,SourceRange InstantiationRange)308 Sema::InstantiatingTemplate::InstantiatingTemplate(
309 Sema &SemaRef, SourceLocation PointOfInstantiation,
310 TemplateDecl *Template,
311 ArrayRef<TemplateArgument> TemplateArgs,
312 sema::TemplateDeductionInfo &DeductionInfo, SourceRange InstantiationRange)
313 : InstantiatingTemplate(
314 SemaRef,
315 CodeSynthesisContext::DeducedTemplateArgumentSubstitution,
316 PointOfInstantiation, InstantiationRange, Template, nullptr,
317 TemplateArgs, &DeductionInfo) {}
318
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,ClassTemplatePartialSpecializationDecl * PartialSpec,ArrayRef<TemplateArgument> TemplateArgs,sema::TemplateDeductionInfo & DeductionInfo,SourceRange InstantiationRange)319 Sema::InstantiatingTemplate::InstantiatingTemplate(
320 Sema &SemaRef, SourceLocation PointOfInstantiation,
321 ClassTemplatePartialSpecializationDecl *PartialSpec,
322 ArrayRef<TemplateArgument> TemplateArgs,
323 sema::TemplateDeductionInfo &DeductionInfo, SourceRange InstantiationRange)
324 : InstantiatingTemplate(
325 SemaRef,
326 CodeSynthesisContext::DeducedTemplateArgumentSubstitution,
327 PointOfInstantiation, InstantiationRange, PartialSpec, nullptr,
328 TemplateArgs, &DeductionInfo) {}
329
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,VarTemplatePartialSpecializationDecl * PartialSpec,ArrayRef<TemplateArgument> TemplateArgs,sema::TemplateDeductionInfo & DeductionInfo,SourceRange InstantiationRange)330 Sema::InstantiatingTemplate::InstantiatingTemplate(
331 Sema &SemaRef, SourceLocation PointOfInstantiation,
332 VarTemplatePartialSpecializationDecl *PartialSpec,
333 ArrayRef<TemplateArgument> TemplateArgs,
334 sema::TemplateDeductionInfo &DeductionInfo, SourceRange InstantiationRange)
335 : InstantiatingTemplate(
336 SemaRef,
337 CodeSynthesisContext::DeducedTemplateArgumentSubstitution,
338 PointOfInstantiation, InstantiationRange, PartialSpec, nullptr,
339 TemplateArgs, &DeductionInfo) {}
340
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,ParmVarDecl * Param,ArrayRef<TemplateArgument> TemplateArgs,SourceRange InstantiationRange)341 Sema::InstantiatingTemplate::InstantiatingTemplate(
342 Sema &SemaRef, SourceLocation PointOfInstantiation, ParmVarDecl *Param,
343 ArrayRef<TemplateArgument> TemplateArgs, SourceRange InstantiationRange)
344 : InstantiatingTemplate(
345 SemaRef,
346 CodeSynthesisContext::DefaultFunctionArgumentInstantiation,
347 PointOfInstantiation, InstantiationRange, Param, nullptr,
348 TemplateArgs) {}
349
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,NamedDecl * Template,NonTypeTemplateParmDecl * Param,ArrayRef<TemplateArgument> TemplateArgs,SourceRange InstantiationRange)350 Sema::InstantiatingTemplate::InstantiatingTemplate(
351 Sema &SemaRef, SourceLocation PointOfInstantiation, NamedDecl *Template,
352 NonTypeTemplateParmDecl *Param, ArrayRef<TemplateArgument> TemplateArgs,
353 SourceRange InstantiationRange)
354 : InstantiatingTemplate(
355 SemaRef,
356 CodeSynthesisContext::PriorTemplateArgumentSubstitution,
357 PointOfInstantiation, InstantiationRange, Param, Template,
358 TemplateArgs) {}
359
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,NamedDecl * Template,TemplateTemplateParmDecl * Param,ArrayRef<TemplateArgument> TemplateArgs,SourceRange InstantiationRange)360 Sema::InstantiatingTemplate::InstantiatingTemplate(
361 Sema &SemaRef, SourceLocation PointOfInstantiation, NamedDecl *Template,
362 TemplateTemplateParmDecl *Param, ArrayRef<TemplateArgument> TemplateArgs,
363 SourceRange InstantiationRange)
364 : InstantiatingTemplate(
365 SemaRef,
366 CodeSynthesisContext::PriorTemplateArgumentSubstitution,
367 PointOfInstantiation, InstantiationRange, Param, Template,
368 TemplateArgs) {}
369
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,TemplateDecl * Template,NamedDecl * Param,ArrayRef<TemplateArgument> TemplateArgs,SourceRange InstantiationRange)370 Sema::InstantiatingTemplate::InstantiatingTemplate(
371 Sema &SemaRef, SourceLocation PointOfInstantiation, TemplateDecl *Template,
372 NamedDecl *Param, ArrayRef<TemplateArgument> TemplateArgs,
373 SourceRange InstantiationRange)
374 : InstantiatingTemplate(
375 SemaRef, CodeSynthesisContext::DefaultTemplateArgumentChecking,
376 PointOfInstantiation, InstantiationRange, Param, Template,
377 TemplateArgs) {}
378
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,concepts::Requirement * Req,sema::TemplateDeductionInfo & DeductionInfo,SourceRange InstantiationRange)379 Sema::InstantiatingTemplate::InstantiatingTemplate(
380 Sema &SemaRef, SourceLocation PointOfInstantiation,
381 concepts::Requirement *Req, sema::TemplateDeductionInfo &DeductionInfo,
382 SourceRange InstantiationRange)
383 : InstantiatingTemplate(
384 SemaRef, CodeSynthesisContext::RequirementInstantiation,
385 PointOfInstantiation, InstantiationRange, /*Entity=*/nullptr,
386 /*Template=*/nullptr, /*TemplateArgs=*/None, &DeductionInfo) {}
387
388
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,concepts::NestedRequirement * Req,ConstraintsCheck,SourceRange InstantiationRange)389 Sema::InstantiatingTemplate::InstantiatingTemplate(
390 Sema &SemaRef, SourceLocation PointOfInstantiation,
391 concepts::NestedRequirement *Req, ConstraintsCheck,
392 SourceRange InstantiationRange)
393 : InstantiatingTemplate(
394 SemaRef, CodeSynthesisContext::NestedRequirementConstraintsCheck,
395 PointOfInstantiation, InstantiationRange, /*Entity=*/nullptr,
396 /*Template=*/nullptr, /*TemplateArgs=*/None) {}
397
398
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,ConstraintsCheck,NamedDecl * Template,ArrayRef<TemplateArgument> TemplateArgs,SourceRange InstantiationRange)399 Sema::InstantiatingTemplate::InstantiatingTemplate(
400 Sema &SemaRef, SourceLocation PointOfInstantiation,
401 ConstraintsCheck, NamedDecl *Template,
402 ArrayRef<TemplateArgument> TemplateArgs, SourceRange InstantiationRange)
403 : InstantiatingTemplate(
404 SemaRef, CodeSynthesisContext::ConstraintsCheck,
405 PointOfInstantiation, InstantiationRange, Template, nullptr,
406 TemplateArgs) {}
407
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,ConstraintSubstitution,NamedDecl * Template,sema::TemplateDeductionInfo & DeductionInfo,SourceRange InstantiationRange)408 Sema::InstantiatingTemplate::InstantiatingTemplate(
409 Sema &SemaRef, SourceLocation PointOfInstantiation,
410 ConstraintSubstitution, NamedDecl *Template,
411 sema::TemplateDeductionInfo &DeductionInfo, SourceRange InstantiationRange)
412 : InstantiatingTemplate(
413 SemaRef, CodeSynthesisContext::ConstraintSubstitution,
414 PointOfInstantiation, InstantiationRange, Template, nullptr,
415 {}, &DeductionInfo) {}
416
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,ConstraintNormalization,NamedDecl * Template,SourceRange InstantiationRange)417 Sema::InstantiatingTemplate::InstantiatingTemplate(
418 Sema &SemaRef, SourceLocation PointOfInstantiation,
419 ConstraintNormalization, NamedDecl *Template,
420 SourceRange InstantiationRange)
421 : InstantiatingTemplate(
422 SemaRef, CodeSynthesisContext::ConstraintNormalization,
423 PointOfInstantiation, InstantiationRange, Template) {}
424
InstantiatingTemplate(Sema & SemaRef,SourceLocation PointOfInstantiation,ParameterMappingSubstitution,NamedDecl * Template,SourceRange InstantiationRange)425 Sema::InstantiatingTemplate::InstantiatingTemplate(
426 Sema &SemaRef, SourceLocation PointOfInstantiation,
427 ParameterMappingSubstitution, NamedDecl *Template,
428 SourceRange InstantiationRange)
429 : InstantiatingTemplate(
430 SemaRef, CodeSynthesisContext::ParameterMappingSubstitution,
431 PointOfInstantiation, InstantiationRange, Template) {}
432
pushCodeSynthesisContext(CodeSynthesisContext Ctx)433 void Sema::pushCodeSynthesisContext(CodeSynthesisContext Ctx) {
434 Ctx.SavedInNonInstantiationSFINAEContext = InNonInstantiationSFINAEContext;
435 InNonInstantiationSFINAEContext = false;
436
437 CodeSynthesisContexts.push_back(Ctx);
438
439 if (!Ctx.isInstantiationRecord())
440 ++NonInstantiationEntries;
441
442 // Check to see if we're low on stack space. We can't do anything about this
443 // from here, but we can at least warn the user.
444 if (isStackNearlyExhausted())
445 warnStackExhausted(Ctx.PointOfInstantiation);
446 }
447
popCodeSynthesisContext()448 void Sema::popCodeSynthesisContext() {
449 auto &Active = CodeSynthesisContexts.back();
450 if (!Active.isInstantiationRecord()) {
451 assert(NonInstantiationEntries > 0);
452 --NonInstantiationEntries;
453 }
454
455 InNonInstantiationSFINAEContext = Active.SavedInNonInstantiationSFINAEContext;
456
457 // Name lookup no longer looks in this template's defining module.
458 assert(CodeSynthesisContexts.size() >=
459 CodeSynthesisContextLookupModules.size() &&
460 "forgot to remove a lookup module for a template instantiation");
461 if (CodeSynthesisContexts.size() ==
462 CodeSynthesisContextLookupModules.size()) {
463 if (Module *M = CodeSynthesisContextLookupModules.back())
464 LookupModulesCache.erase(M);
465 CodeSynthesisContextLookupModules.pop_back();
466 }
467
468 // If we've left the code synthesis context for the current context stack,
469 // stop remembering that we've emitted that stack.
470 if (CodeSynthesisContexts.size() ==
471 LastEmittedCodeSynthesisContextDepth)
472 LastEmittedCodeSynthesisContextDepth = 0;
473
474 CodeSynthesisContexts.pop_back();
475 }
476
Clear()477 void Sema::InstantiatingTemplate::Clear() {
478 if (!Invalid) {
479 if (!AlreadyInstantiating) {
480 auto &Active = SemaRef.CodeSynthesisContexts.back();
481 if (Active.Entity)
482 SemaRef.InstantiatingSpecializations.erase(
483 {Active.Entity->getCanonicalDecl(), Active.Kind});
484 }
485
486 atTemplateEnd(SemaRef.TemplateInstCallbacks, SemaRef,
487 SemaRef.CodeSynthesisContexts.back());
488
489 SemaRef.popCodeSynthesisContext();
490 Invalid = true;
491 }
492 }
493
CheckInstantiationDepth(SourceLocation PointOfInstantiation,SourceRange InstantiationRange)494 bool Sema::InstantiatingTemplate::CheckInstantiationDepth(
495 SourceLocation PointOfInstantiation,
496 SourceRange InstantiationRange) {
497 assert(SemaRef.NonInstantiationEntries <=
498 SemaRef.CodeSynthesisContexts.size());
499 if ((SemaRef.CodeSynthesisContexts.size() -
500 SemaRef.NonInstantiationEntries)
501 <= SemaRef.getLangOpts().InstantiationDepth)
502 return false;
503
504 SemaRef.Diag(PointOfInstantiation,
505 diag::err_template_recursion_depth_exceeded)
506 << SemaRef.getLangOpts().InstantiationDepth
507 << InstantiationRange;
508 SemaRef.Diag(PointOfInstantiation, diag::note_template_recursion_depth)
509 << SemaRef.getLangOpts().InstantiationDepth;
510 return true;
511 }
512
513 /// Prints the current instantiation stack through a series of
514 /// notes.
PrintInstantiationStack()515 void Sema::PrintInstantiationStack() {
516 // Determine which template instantiations to skip, if any.
517 unsigned SkipStart = CodeSynthesisContexts.size(), SkipEnd = SkipStart;
518 unsigned Limit = Diags.getTemplateBacktraceLimit();
519 if (Limit && Limit < CodeSynthesisContexts.size()) {
520 SkipStart = Limit / 2 + Limit % 2;
521 SkipEnd = CodeSynthesisContexts.size() - Limit / 2;
522 }
523
524 // FIXME: In all of these cases, we need to show the template arguments
525 unsigned InstantiationIdx = 0;
526 for (SmallVectorImpl<CodeSynthesisContext>::reverse_iterator
527 Active = CodeSynthesisContexts.rbegin(),
528 ActiveEnd = CodeSynthesisContexts.rend();
529 Active != ActiveEnd;
530 ++Active, ++InstantiationIdx) {
531 // Skip this instantiation?
532 if (InstantiationIdx >= SkipStart && InstantiationIdx < SkipEnd) {
533 if (InstantiationIdx == SkipStart) {
534 // Note that we're skipping instantiations.
535 Diags.Report(Active->PointOfInstantiation,
536 diag::note_instantiation_contexts_suppressed)
537 << unsigned(CodeSynthesisContexts.size() - Limit);
538 }
539 continue;
540 }
541
542 switch (Active->Kind) {
543 case CodeSynthesisContext::TemplateInstantiation: {
544 Decl *D = Active->Entity;
545 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
546 unsigned DiagID = diag::note_template_member_class_here;
547 if (isa<ClassTemplateSpecializationDecl>(Record))
548 DiagID = diag::note_template_class_instantiation_here;
549 Diags.Report(Active->PointOfInstantiation, DiagID)
550 << Record << Active->InstantiationRange;
551 } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) {
552 unsigned DiagID;
553 if (Function->getPrimaryTemplate())
554 DiagID = diag::note_function_template_spec_here;
555 else
556 DiagID = diag::note_template_member_function_here;
557 Diags.Report(Active->PointOfInstantiation, DiagID)
558 << Function
559 << Active->InstantiationRange;
560 } else if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
561 Diags.Report(Active->PointOfInstantiation,
562 VD->isStaticDataMember()?
563 diag::note_template_static_data_member_def_here
564 : diag::note_template_variable_def_here)
565 << VD
566 << Active->InstantiationRange;
567 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(D)) {
568 Diags.Report(Active->PointOfInstantiation,
569 diag::note_template_enum_def_here)
570 << ED
571 << Active->InstantiationRange;
572 } else if (FieldDecl *FD = dyn_cast<FieldDecl>(D)) {
573 Diags.Report(Active->PointOfInstantiation,
574 diag::note_template_nsdmi_here)
575 << FD << Active->InstantiationRange;
576 } else {
577 Diags.Report(Active->PointOfInstantiation,
578 diag::note_template_type_alias_instantiation_here)
579 << cast<TypeAliasTemplateDecl>(D)
580 << Active->InstantiationRange;
581 }
582 break;
583 }
584
585 case CodeSynthesisContext::DefaultTemplateArgumentInstantiation: {
586 TemplateDecl *Template = cast<TemplateDecl>(Active->Template);
587 SmallString<128> TemplateArgsStr;
588 llvm::raw_svector_ostream OS(TemplateArgsStr);
589 Template->printName(OS);
590 printTemplateArgumentList(OS, Active->template_arguments(),
591 getPrintingPolicy());
592 Diags.Report(Active->PointOfInstantiation,
593 diag::note_default_arg_instantiation_here)
594 << OS.str()
595 << Active->InstantiationRange;
596 break;
597 }
598
599 case CodeSynthesisContext::ExplicitTemplateArgumentSubstitution: {
600 FunctionTemplateDecl *FnTmpl = cast<FunctionTemplateDecl>(Active->Entity);
601 Diags.Report(Active->PointOfInstantiation,
602 diag::note_explicit_template_arg_substitution_here)
603 << FnTmpl
604 << getTemplateArgumentBindingsText(FnTmpl->getTemplateParameters(),
605 Active->TemplateArgs,
606 Active->NumTemplateArgs)
607 << Active->InstantiationRange;
608 break;
609 }
610
611 case CodeSynthesisContext::DeducedTemplateArgumentSubstitution: {
612 if (FunctionTemplateDecl *FnTmpl =
613 dyn_cast<FunctionTemplateDecl>(Active->Entity)) {
614 Diags.Report(Active->PointOfInstantiation,
615 diag::note_function_template_deduction_instantiation_here)
616 << FnTmpl
617 << getTemplateArgumentBindingsText(FnTmpl->getTemplateParameters(),
618 Active->TemplateArgs,
619 Active->NumTemplateArgs)
620 << Active->InstantiationRange;
621 } else {
622 bool IsVar = isa<VarTemplateDecl>(Active->Entity) ||
623 isa<VarTemplateSpecializationDecl>(Active->Entity);
624 bool IsTemplate = false;
625 TemplateParameterList *Params;
626 if (auto *D = dyn_cast<TemplateDecl>(Active->Entity)) {
627 IsTemplate = true;
628 Params = D->getTemplateParameters();
629 } else if (auto *D = dyn_cast<ClassTemplatePartialSpecializationDecl>(
630 Active->Entity)) {
631 Params = D->getTemplateParameters();
632 } else if (auto *D = dyn_cast<VarTemplatePartialSpecializationDecl>(
633 Active->Entity)) {
634 Params = D->getTemplateParameters();
635 } else {
636 llvm_unreachable("unexpected template kind");
637 }
638
639 Diags.Report(Active->PointOfInstantiation,
640 diag::note_deduced_template_arg_substitution_here)
641 << IsVar << IsTemplate << cast<NamedDecl>(Active->Entity)
642 << getTemplateArgumentBindingsText(Params, Active->TemplateArgs,
643 Active->NumTemplateArgs)
644 << Active->InstantiationRange;
645 }
646 break;
647 }
648
649 case CodeSynthesisContext::DefaultFunctionArgumentInstantiation: {
650 ParmVarDecl *Param = cast<ParmVarDecl>(Active->Entity);
651 FunctionDecl *FD = cast<FunctionDecl>(Param->getDeclContext());
652
653 SmallString<128> TemplateArgsStr;
654 llvm::raw_svector_ostream OS(TemplateArgsStr);
655 FD->printName(OS);
656 printTemplateArgumentList(OS, Active->template_arguments(),
657 getPrintingPolicy());
658 Diags.Report(Active->PointOfInstantiation,
659 diag::note_default_function_arg_instantiation_here)
660 << OS.str()
661 << Active->InstantiationRange;
662 break;
663 }
664
665 case CodeSynthesisContext::PriorTemplateArgumentSubstitution: {
666 NamedDecl *Parm = cast<NamedDecl>(Active->Entity);
667 std::string Name;
668 if (!Parm->getName().empty())
669 Name = std::string(" '") + Parm->getName().str() + "'";
670
671 TemplateParameterList *TemplateParams = nullptr;
672 if (TemplateDecl *Template = dyn_cast<TemplateDecl>(Active->Template))
673 TemplateParams = Template->getTemplateParameters();
674 else
675 TemplateParams =
676 cast<ClassTemplatePartialSpecializationDecl>(Active->Template)
677 ->getTemplateParameters();
678 Diags.Report(Active->PointOfInstantiation,
679 diag::note_prior_template_arg_substitution)
680 << isa<TemplateTemplateParmDecl>(Parm)
681 << Name
682 << getTemplateArgumentBindingsText(TemplateParams,
683 Active->TemplateArgs,
684 Active->NumTemplateArgs)
685 << Active->InstantiationRange;
686 break;
687 }
688
689 case CodeSynthesisContext::DefaultTemplateArgumentChecking: {
690 TemplateParameterList *TemplateParams = nullptr;
691 if (TemplateDecl *Template = dyn_cast<TemplateDecl>(Active->Template))
692 TemplateParams = Template->getTemplateParameters();
693 else
694 TemplateParams =
695 cast<ClassTemplatePartialSpecializationDecl>(Active->Template)
696 ->getTemplateParameters();
697
698 Diags.Report(Active->PointOfInstantiation,
699 diag::note_template_default_arg_checking)
700 << getTemplateArgumentBindingsText(TemplateParams,
701 Active->TemplateArgs,
702 Active->NumTemplateArgs)
703 << Active->InstantiationRange;
704 break;
705 }
706
707 case CodeSynthesisContext::ExceptionSpecEvaluation:
708 Diags.Report(Active->PointOfInstantiation,
709 diag::note_evaluating_exception_spec_here)
710 << cast<FunctionDecl>(Active->Entity);
711 break;
712
713 case CodeSynthesisContext::ExceptionSpecInstantiation:
714 Diags.Report(Active->PointOfInstantiation,
715 diag::note_template_exception_spec_instantiation_here)
716 << cast<FunctionDecl>(Active->Entity)
717 << Active->InstantiationRange;
718 break;
719
720 case CodeSynthesisContext::RequirementInstantiation:
721 Diags.Report(Active->PointOfInstantiation,
722 diag::note_template_requirement_instantiation_here)
723 << Active->InstantiationRange;
724 break;
725
726 case CodeSynthesisContext::NestedRequirementConstraintsCheck:
727 Diags.Report(Active->PointOfInstantiation,
728 diag::note_nested_requirement_here)
729 << Active->InstantiationRange;
730 break;
731
732 case CodeSynthesisContext::DeclaringSpecialMember:
733 Diags.Report(Active->PointOfInstantiation,
734 diag::note_in_declaration_of_implicit_special_member)
735 << cast<CXXRecordDecl>(Active->Entity) << Active->SpecialMember;
736 break;
737
738 case CodeSynthesisContext::DeclaringImplicitEqualityComparison:
739 Diags.Report(Active->Entity->getLocation(),
740 diag::note_in_declaration_of_implicit_equality_comparison);
741 break;
742
743 case CodeSynthesisContext::DefiningSynthesizedFunction: {
744 // FIXME: For synthesized functions that are not defaulted,
745 // produce a note.
746 auto *FD = dyn_cast<FunctionDecl>(Active->Entity);
747 DefaultedFunctionKind DFK =
748 FD ? getDefaultedFunctionKind(FD) : DefaultedFunctionKind();
749 if (DFK.isSpecialMember()) {
750 auto *MD = cast<CXXMethodDecl>(FD);
751 Diags.Report(Active->PointOfInstantiation,
752 diag::note_member_synthesized_at)
753 << MD->isExplicitlyDefaulted() << DFK.asSpecialMember()
754 << Context.getTagDeclType(MD->getParent());
755 } else if (DFK.isComparison()) {
756 Diags.Report(Active->PointOfInstantiation,
757 diag::note_comparison_synthesized_at)
758 << (int)DFK.asComparison()
759 << Context.getTagDeclType(
760 cast<CXXRecordDecl>(FD->getLexicalDeclContext()));
761 }
762 break;
763 }
764
765 case CodeSynthesisContext::RewritingOperatorAsSpaceship:
766 Diags.Report(Active->Entity->getLocation(),
767 diag::note_rewriting_operator_as_spaceship);
768 break;
769
770 case CodeSynthesisContext::InitializingStructuredBinding:
771 Diags.Report(Active->PointOfInstantiation,
772 diag::note_in_binding_decl_init)
773 << cast<BindingDecl>(Active->Entity);
774 break;
775
776 case CodeSynthesisContext::MarkingClassDllexported:
777 Diags.Report(Active->PointOfInstantiation,
778 diag::note_due_to_dllexported_class)
779 << cast<CXXRecordDecl>(Active->Entity) << !getLangOpts().CPlusPlus11;
780 break;
781
782 case CodeSynthesisContext::Memoization:
783 break;
784
785 case CodeSynthesisContext::ConstraintsCheck: {
786 unsigned DiagID = 0;
787 if (!Active->Entity) {
788 Diags.Report(Active->PointOfInstantiation,
789 diag::note_nested_requirement_here)
790 << Active->InstantiationRange;
791 break;
792 }
793 if (isa<ConceptDecl>(Active->Entity))
794 DiagID = diag::note_concept_specialization_here;
795 else if (isa<TemplateDecl>(Active->Entity))
796 DiagID = diag::note_checking_constraints_for_template_id_here;
797 else if (isa<VarTemplatePartialSpecializationDecl>(Active->Entity))
798 DiagID = diag::note_checking_constraints_for_var_spec_id_here;
799 else if (isa<ClassTemplatePartialSpecializationDecl>(Active->Entity))
800 DiagID = diag::note_checking_constraints_for_class_spec_id_here;
801 else {
802 assert(isa<FunctionDecl>(Active->Entity));
803 DiagID = diag::note_checking_constraints_for_function_here;
804 }
805 SmallString<128> TemplateArgsStr;
806 llvm::raw_svector_ostream OS(TemplateArgsStr);
807 cast<NamedDecl>(Active->Entity)->printName(OS);
808 if (!isa<FunctionDecl>(Active->Entity))
809 printTemplateArgumentList(OS, Active->template_arguments(),
810 getPrintingPolicy());
811 Diags.Report(Active->PointOfInstantiation, DiagID) << OS.str()
812 << Active->InstantiationRange;
813 break;
814 }
815 case CodeSynthesisContext::ConstraintSubstitution:
816 Diags.Report(Active->PointOfInstantiation,
817 diag::note_constraint_substitution_here)
818 << Active->InstantiationRange;
819 break;
820 case CodeSynthesisContext::ConstraintNormalization:
821 Diags.Report(Active->PointOfInstantiation,
822 diag::note_constraint_normalization_here)
823 << cast<NamedDecl>(Active->Entity)->getName()
824 << Active->InstantiationRange;
825 break;
826 case CodeSynthesisContext::ParameterMappingSubstitution:
827 Diags.Report(Active->PointOfInstantiation,
828 diag::note_parameter_mapping_substitution_here)
829 << Active->InstantiationRange;
830 break;
831 }
832 }
833 }
834
isSFINAEContext() const835 Optional<TemplateDeductionInfo *> Sema::isSFINAEContext() const {
836 if (InNonInstantiationSFINAEContext)
837 return Optional<TemplateDeductionInfo *>(nullptr);
838
839 for (SmallVectorImpl<CodeSynthesisContext>::const_reverse_iterator
840 Active = CodeSynthesisContexts.rbegin(),
841 ActiveEnd = CodeSynthesisContexts.rend();
842 Active != ActiveEnd;
843 ++Active)
844 {
845 switch (Active->Kind) {
846 case CodeSynthesisContext::TemplateInstantiation:
847 // An instantiation of an alias template may or may not be a SFINAE
848 // context, depending on what else is on the stack.
849 if (isa<TypeAliasTemplateDecl>(Active->Entity))
850 break;
851 LLVM_FALLTHROUGH;
852 case CodeSynthesisContext::DefaultFunctionArgumentInstantiation:
853 case CodeSynthesisContext::ExceptionSpecInstantiation:
854 case CodeSynthesisContext::ConstraintsCheck:
855 case CodeSynthesisContext::ParameterMappingSubstitution:
856 case CodeSynthesisContext::ConstraintNormalization:
857 case CodeSynthesisContext::NestedRequirementConstraintsCheck:
858 // This is a template instantiation, so there is no SFINAE.
859 return None;
860
861 case CodeSynthesisContext::DefaultTemplateArgumentInstantiation:
862 case CodeSynthesisContext::PriorTemplateArgumentSubstitution:
863 case CodeSynthesisContext::DefaultTemplateArgumentChecking:
864 case CodeSynthesisContext::RewritingOperatorAsSpaceship:
865 // A default template argument instantiation and substitution into
866 // template parameters with arguments for prior parameters may or may
867 // not be a SFINAE context; look further up the stack.
868 break;
869
870 case CodeSynthesisContext::ExplicitTemplateArgumentSubstitution:
871 case CodeSynthesisContext::DeducedTemplateArgumentSubstitution:
872 case CodeSynthesisContext::ConstraintSubstitution:
873 case CodeSynthesisContext::RequirementInstantiation:
874 // We're either substituting explicitly-specified template arguments,
875 // deduced template arguments, a constraint expression or a requirement
876 // in a requires expression, so SFINAE applies.
877 assert(Active->DeductionInfo && "Missing deduction info pointer");
878 return Active->DeductionInfo;
879
880 case CodeSynthesisContext::DeclaringSpecialMember:
881 case CodeSynthesisContext::DeclaringImplicitEqualityComparison:
882 case CodeSynthesisContext::DefiningSynthesizedFunction:
883 case CodeSynthesisContext::InitializingStructuredBinding:
884 case CodeSynthesisContext::MarkingClassDllexported:
885 // This happens in a context unrelated to template instantiation, so
886 // there is no SFINAE.
887 return None;
888
889 case CodeSynthesisContext::ExceptionSpecEvaluation:
890 // FIXME: This should not be treated as a SFINAE context, because
891 // we will cache an incorrect exception specification. However, clang
892 // bootstrap relies this! See PR31692.
893 break;
894
895 case CodeSynthesisContext::Memoization:
896 break;
897 }
898
899 // The inner context was transparent for SFINAE. If it occurred within a
900 // non-instantiation SFINAE context, then SFINAE applies.
901 if (Active->SavedInNonInstantiationSFINAEContext)
902 return Optional<TemplateDeductionInfo *>(nullptr);
903 }
904
905 return None;
906 }
907
908 //===----------------------------------------------------------------------===/
909 // Template Instantiation for Types
910 //===----------------------------------------------------------------------===/
911 namespace {
912 class TemplateInstantiator : public TreeTransform<TemplateInstantiator> {
913 const MultiLevelTemplateArgumentList &TemplateArgs;
914 SourceLocation Loc;
915 DeclarationName Entity;
916
917 public:
918 typedef TreeTransform<TemplateInstantiator> inherited;
919
TemplateInstantiator(Sema & SemaRef,const MultiLevelTemplateArgumentList & TemplateArgs,SourceLocation Loc,DeclarationName Entity)920 TemplateInstantiator(Sema &SemaRef,
921 const MultiLevelTemplateArgumentList &TemplateArgs,
922 SourceLocation Loc,
923 DeclarationName Entity)
924 : inherited(SemaRef), TemplateArgs(TemplateArgs), Loc(Loc),
925 Entity(Entity) { }
926
927 /// Determine whether the given type \p T has already been
928 /// transformed.
929 ///
930 /// For the purposes of template instantiation, a type has already been
931 /// transformed if it is NULL or if it is not dependent.
932 bool AlreadyTransformed(QualType T);
933
934 /// Returns the location of the entity being instantiated, if known.
getBaseLocation()935 SourceLocation getBaseLocation() { return Loc; }
936
937 /// Returns the name of the entity being instantiated, if any.
getBaseEntity()938 DeclarationName getBaseEntity() { return Entity; }
939
940 /// Sets the "base" location and entity when that
941 /// information is known based on another transformation.
setBase(SourceLocation Loc,DeclarationName Entity)942 void setBase(SourceLocation Loc, DeclarationName Entity) {
943 this->Loc = Loc;
944 this->Entity = Entity;
945 }
946
TransformTemplateDepth(unsigned Depth)947 unsigned TransformTemplateDepth(unsigned Depth) {
948 return TemplateArgs.getNewDepth(Depth);
949 }
950
TryExpandParameterPacks(SourceLocation EllipsisLoc,SourceRange PatternRange,ArrayRef<UnexpandedParameterPack> Unexpanded,bool & ShouldExpand,bool & RetainExpansion,Optional<unsigned> & NumExpansions)951 bool TryExpandParameterPacks(SourceLocation EllipsisLoc,
952 SourceRange PatternRange,
953 ArrayRef<UnexpandedParameterPack> Unexpanded,
954 bool &ShouldExpand, bool &RetainExpansion,
955 Optional<unsigned> &NumExpansions) {
956 return getSema().CheckParameterPacksForExpansion(EllipsisLoc,
957 PatternRange, Unexpanded,
958 TemplateArgs,
959 ShouldExpand,
960 RetainExpansion,
961 NumExpansions);
962 }
963
ExpandingFunctionParameterPack(ParmVarDecl * Pack)964 void ExpandingFunctionParameterPack(ParmVarDecl *Pack) {
965 SemaRef.CurrentInstantiationScope->MakeInstantiatedLocalArgPack(Pack);
966 }
967
ForgetPartiallySubstitutedPack()968 TemplateArgument ForgetPartiallySubstitutedPack() {
969 TemplateArgument Result;
970 if (NamedDecl *PartialPack
971 = SemaRef.CurrentInstantiationScope->getPartiallySubstitutedPack()){
972 MultiLevelTemplateArgumentList &TemplateArgs
973 = const_cast<MultiLevelTemplateArgumentList &>(this->TemplateArgs);
974 unsigned Depth, Index;
975 std::tie(Depth, Index) = getDepthAndIndex(PartialPack);
976 if (TemplateArgs.hasTemplateArgument(Depth, Index)) {
977 Result = TemplateArgs(Depth, Index);
978 TemplateArgs.setArgument(Depth, Index, TemplateArgument());
979 }
980 }
981
982 return Result;
983 }
984
RememberPartiallySubstitutedPack(TemplateArgument Arg)985 void RememberPartiallySubstitutedPack(TemplateArgument Arg) {
986 if (Arg.isNull())
987 return;
988
989 if (NamedDecl *PartialPack
990 = SemaRef.CurrentInstantiationScope->getPartiallySubstitutedPack()){
991 MultiLevelTemplateArgumentList &TemplateArgs
992 = const_cast<MultiLevelTemplateArgumentList &>(this->TemplateArgs);
993 unsigned Depth, Index;
994 std::tie(Depth, Index) = getDepthAndIndex(PartialPack);
995 TemplateArgs.setArgument(Depth, Index, Arg);
996 }
997 }
998
999 /// Transform the given declaration by instantiating a reference to
1000 /// this declaration.
1001 Decl *TransformDecl(SourceLocation Loc, Decl *D);
1002
transformAttrs(Decl * Old,Decl * New)1003 void transformAttrs(Decl *Old, Decl *New) {
1004 SemaRef.InstantiateAttrs(TemplateArgs, Old, New);
1005 }
1006
transformedLocalDecl(Decl * Old,ArrayRef<Decl * > NewDecls)1007 void transformedLocalDecl(Decl *Old, ArrayRef<Decl *> NewDecls) {
1008 if (Old->isParameterPack()) {
1009 SemaRef.CurrentInstantiationScope->MakeInstantiatedLocalArgPack(Old);
1010 for (auto *New : NewDecls)
1011 SemaRef.CurrentInstantiationScope->InstantiatedLocalPackArg(
1012 Old, cast<VarDecl>(New));
1013 return;
1014 }
1015
1016 assert(NewDecls.size() == 1 &&
1017 "should only have multiple expansions for a pack");
1018 Decl *New = NewDecls.front();
1019
1020 // If we've instantiated the call operator of a lambda or the call
1021 // operator template of a generic lambda, update the "instantiation of"
1022 // information.
1023 auto *NewMD = dyn_cast<CXXMethodDecl>(New);
1024 if (NewMD && isLambdaCallOperator(NewMD)) {
1025 auto *OldMD = dyn_cast<CXXMethodDecl>(Old);
1026 if (auto *NewTD = NewMD->getDescribedFunctionTemplate())
1027 NewTD->setInstantiatedFromMemberTemplate(
1028 OldMD->getDescribedFunctionTemplate());
1029 else
1030 NewMD->setInstantiationOfMemberFunction(OldMD,
1031 TSK_ImplicitInstantiation);
1032 }
1033
1034 SemaRef.CurrentInstantiationScope->InstantiatedLocal(Old, New);
1035
1036 // We recreated a local declaration, but not by instantiating it. There
1037 // may be pending dependent diagnostics to produce.
1038 if (auto *DC = dyn_cast<DeclContext>(Old))
1039 SemaRef.PerformDependentDiagnostics(DC, TemplateArgs);
1040 }
1041
1042 /// Transform the definition of the given declaration by
1043 /// instantiating it.
1044 Decl *TransformDefinition(SourceLocation Loc, Decl *D);
1045
1046 /// Transform the first qualifier within a scope by instantiating the
1047 /// declaration.
1048 NamedDecl *TransformFirstQualifierInScope(NamedDecl *D, SourceLocation Loc);
1049
1050 /// Rebuild the exception declaration and register the declaration
1051 /// as an instantiated local.
1052 VarDecl *RebuildExceptionDecl(VarDecl *ExceptionDecl,
1053 TypeSourceInfo *Declarator,
1054 SourceLocation StartLoc,
1055 SourceLocation NameLoc,
1056 IdentifierInfo *Name);
1057
1058 /// Rebuild the Objective-C exception declaration and register the
1059 /// declaration as an instantiated local.
1060 VarDecl *RebuildObjCExceptionDecl(VarDecl *ExceptionDecl,
1061 TypeSourceInfo *TSInfo, QualType T);
1062
1063 /// Check for tag mismatches when instantiating an
1064 /// elaborated type.
1065 QualType RebuildElaboratedType(SourceLocation KeywordLoc,
1066 ElaboratedTypeKeyword Keyword,
1067 NestedNameSpecifierLoc QualifierLoc,
1068 QualType T);
1069
1070 TemplateName
1071 TransformTemplateName(CXXScopeSpec &SS, TemplateName Name,
1072 SourceLocation NameLoc,
1073 QualType ObjectType = QualType(),
1074 NamedDecl *FirstQualifierInScope = nullptr,
1075 bool AllowInjectedClassName = false);
1076
1077 const LoopHintAttr *TransformLoopHintAttr(const LoopHintAttr *LH);
1078
1079 ExprResult TransformPredefinedExpr(PredefinedExpr *E);
1080 ExprResult TransformDeclRefExpr(DeclRefExpr *E);
1081 ExprResult TransformCXXDefaultArgExpr(CXXDefaultArgExpr *E);
1082
1083 ExprResult TransformTemplateParmRefExpr(DeclRefExpr *E,
1084 NonTypeTemplateParmDecl *D);
1085 ExprResult TransformSubstNonTypeTemplateParmPackExpr(
1086 SubstNonTypeTemplateParmPackExpr *E);
1087 ExprResult TransformSubstNonTypeTemplateParmExpr(
1088 SubstNonTypeTemplateParmExpr *E);
1089
1090 /// Rebuild a DeclRefExpr for a VarDecl reference.
1091 ExprResult RebuildVarDeclRefExpr(VarDecl *PD, SourceLocation Loc);
1092
1093 /// Transform a reference to a function or init-capture parameter pack.
1094 ExprResult TransformFunctionParmPackRefExpr(DeclRefExpr *E, VarDecl *PD);
1095
1096 /// Transform a FunctionParmPackExpr which was built when we couldn't
1097 /// expand a function parameter pack reference which refers to an expanded
1098 /// pack.
1099 ExprResult TransformFunctionParmPackExpr(FunctionParmPackExpr *E);
1100
TransformFunctionProtoType(TypeLocBuilder & TLB,FunctionProtoTypeLoc TL)1101 QualType TransformFunctionProtoType(TypeLocBuilder &TLB,
1102 FunctionProtoTypeLoc TL) {
1103 // Call the base version; it will forward to our overridden version below.
1104 return inherited::TransformFunctionProtoType(TLB, TL);
1105 }
1106
1107 template<typename Fn>
1108 QualType TransformFunctionProtoType(TypeLocBuilder &TLB,
1109 FunctionProtoTypeLoc TL,
1110 CXXRecordDecl *ThisContext,
1111 Qualifiers ThisTypeQuals,
1112 Fn TransformExceptionSpec);
1113
1114 ParmVarDecl *TransformFunctionTypeParam(ParmVarDecl *OldParm,
1115 int indexAdjustment,
1116 Optional<unsigned> NumExpansions,
1117 bool ExpectParameterPack);
1118
1119 /// Transforms a template type parameter type by performing
1120 /// substitution of the corresponding template type argument.
1121 QualType TransformTemplateTypeParmType(TypeLocBuilder &TLB,
1122 TemplateTypeParmTypeLoc TL);
1123
1124 /// Transforms an already-substituted template type parameter pack
1125 /// into either itself (if we aren't substituting into its pack expansion)
1126 /// or the appropriate substituted argument.
1127 QualType TransformSubstTemplateTypeParmPackType(TypeLocBuilder &TLB,
1128 SubstTemplateTypeParmPackTypeLoc TL);
1129
TransformLambdaExpr(LambdaExpr * E)1130 ExprResult TransformLambdaExpr(LambdaExpr *E) {
1131 LocalInstantiationScope Scope(SemaRef, /*CombineWithOuterScope=*/true);
1132 return TreeTransform<TemplateInstantiator>::TransformLambdaExpr(E);
1133 }
1134
TransformRequiresExpr(RequiresExpr * E)1135 ExprResult TransformRequiresExpr(RequiresExpr *E) {
1136 LocalInstantiationScope Scope(SemaRef, /*CombineWithOuterScope=*/true);
1137 return TreeTransform<TemplateInstantiator>::TransformRequiresExpr(E);
1138 }
1139
TransformRequiresExprRequirements(ArrayRef<concepts::Requirement * > Reqs,SmallVectorImpl<concepts::Requirement * > & Transformed)1140 bool TransformRequiresExprRequirements(
1141 ArrayRef<concepts::Requirement *> Reqs,
1142 SmallVectorImpl<concepts::Requirement *> &Transformed) {
1143 bool SatisfactionDetermined = false;
1144 for (concepts::Requirement *Req : Reqs) {
1145 concepts::Requirement *TransReq = nullptr;
1146 if (!SatisfactionDetermined) {
1147 if (auto *TypeReq = dyn_cast<concepts::TypeRequirement>(Req))
1148 TransReq = TransformTypeRequirement(TypeReq);
1149 else if (auto *ExprReq = dyn_cast<concepts::ExprRequirement>(Req))
1150 TransReq = TransformExprRequirement(ExprReq);
1151 else
1152 TransReq = TransformNestedRequirement(
1153 cast<concepts::NestedRequirement>(Req));
1154 if (!TransReq)
1155 return true;
1156 if (!TransReq->isDependent() && !TransReq->isSatisfied())
1157 // [expr.prim.req]p6
1158 // [...] The substitution and semantic constraint checking
1159 // proceeds in lexical order and stops when a condition that
1160 // determines the result of the requires-expression is
1161 // encountered. [..]
1162 SatisfactionDetermined = true;
1163 } else
1164 TransReq = Req;
1165 Transformed.push_back(TransReq);
1166 }
1167 return false;
1168 }
1169
TransformTemplateParameterList(TemplateParameterList * OrigTPL)1170 TemplateParameterList *TransformTemplateParameterList(
1171 TemplateParameterList *OrigTPL) {
1172 if (!OrigTPL || !OrigTPL->size()) return OrigTPL;
1173
1174 DeclContext *Owner = OrigTPL->getParam(0)->getDeclContext();
1175 TemplateDeclInstantiator DeclInstantiator(getSema(),
1176 /* DeclContext *Owner */ Owner, TemplateArgs);
1177 return DeclInstantiator.SubstTemplateParams(OrigTPL);
1178 }
1179
1180 concepts::TypeRequirement *
1181 TransformTypeRequirement(concepts::TypeRequirement *Req);
1182 concepts::ExprRequirement *
1183 TransformExprRequirement(concepts::ExprRequirement *Req);
1184 concepts::NestedRequirement *
1185 TransformNestedRequirement(concepts::NestedRequirement *Req);
1186
1187 private:
1188 ExprResult transformNonTypeTemplateParmRef(NonTypeTemplateParmDecl *parm,
1189 SourceLocation loc,
1190 TemplateArgument arg);
1191 };
1192 }
1193
AlreadyTransformed(QualType T)1194 bool TemplateInstantiator::AlreadyTransformed(QualType T) {
1195 if (T.isNull())
1196 return true;
1197
1198 if (T->isInstantiationDependentType() || T->isVariablyModifiedType())
1199 return false;
1200
1201 getSema().MarkDeclarationsReferencedInType(Loc, T);
1202 return true;
1203 }
1204
1205 static TemplateArgument
getPackSubstitutedTemplateArgument(Sema & S,TemplateArgument Arg)1206 getPackSubstitutedTemplateArgument(Sema &S, TemplateArgument Arg) {
1207 assert(S.ArgumentPackSubstitutionIndex >= 0);
1208 assert(S.ArgumentPackSubstitutionIndex < (int)Arg.pack_size());
1209 Arg = Arg.pack_begin()[S.ArgumentPackSubstitutionIndex];
1210 if (Arg.isPackExpansion())
1211 Arg = Arg.getPackExpansionPattern();
1212 return Arg;
1213 }
1214
TransformDecl(SourceLocation Loc,Decl * D)1215 Decl *TemplateInstantiator::TransformDecl(SourceLocation Loc, Decl *D) {
1216 if (!D)
1217 return nullptr;
1218
1219 if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(D)) {
1220 if (TTP->getDepth() < TemplateArgs.getNumLevels()) {
1221 // If the corresponding template argument is NULL or non-existent, it's
1222 // because we are performing instantiation from explicitly-specified
1223 // template arguments in a function template, but there were some
1224 // arguments left unspecified.
1225 if (!TemplateArgs.hasTemplateArgument(TTP->getDepth(),
1226 TTP->getPosition()))
1227 return D;
1228
1229 TemplateArgument Arg = TemplateArgs(TTP->getDepth(), TTP->getPosition());
1230
1231 if (TTP->isParameterPack()) {
1232 assert(Arg.getKind() == TemplateArgument::Pack &&
1233 "Missing argument pack");
1234 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1235 }
1236
1237 TemplateName Template = Arg.getAsTemplate().getNameToSubstitute();
1238 assert(!Template.isNull() && Template.getAsTemplateDecl() &&
1239 "Wrong kind of template template argument");
1240 return Template.getAsTemplateDecl();
1241 }
1242
1243 // Fall through to find the instantiated declaration for this template
1244 // template parameter.
1245 }
1246
1247 return SemaRef.FindInstantiatedDecl(Loc, cast<NamedDecl>(D), TemplateArgs);
1248 }
1249
TransformDefinition(SourceLocation Loc,Decl * D)1250 Decl *TemplateInstantiator::TransformDefinition(SourceLocation Loc, Decl *D) {
1251 Decl *Inst = getSema().SubstDecl(D, getSema().CurContext, TemplateArgs);
1252 if (!Inst)
1253 return nullptr;
1254
1255 getSema().CurrentInstantiationScope->InstantiatedLocal(D, Inst);
1256 return Inst;
1257 }
1258
1259 NamedDecl *
TransformFirstQualifierInScope(NamedDecl * D,SourceLocation Loc)1260 TemplateInstantiator::TransformFirstQualifierInScope(NamedDecl *D,
1261 SourceLocation Loc) {
1262 // If the first part of the nested-name-specifier was a template type
1263 // parameter, instantiate that type parameter down to a tag type.
1264 if (TemplateTypeParmDecl *TTPD = dyn_cast_or_null<TemplateTypeParmDecl>(D)) {
1265 const TemplateTypeParmType *TTP
1266 = cast<TemplateTypeParmType>(getSema().Context.getTypeDeclType(TTPD));
1267
1268 if (TTP->getDepth() < TemplateArgs.getNumLevels()) {
1269 // FIXME: This needs testing w/ member access expressions.
1270 TemplateArgument Arg = TemplateArgs(TTP->getDepth(), TTP->getIndex());
1271
1272 if (TTP->isParameterPack()) {
1273 assert(Arg.getKind() == TemplateArgument::Pack &&
1274 "Missing argument pack");
1275
1276 if (getSema().ArgumentPackSubstitutionIndex == -1)
1277 return nullptr;
1278
1279 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1280 }
1281
1282 QualType T = Arg.getAsType();
1283 if (T.isNull())
1284 return cast_or_null<NamedDecl>(TransformDecl(Loc, D));
1285
1286 if (const TagType *Tag = T->getAs<TagType>())
1287 return Tag->getDecl();
1288
1289 // The resulting type is not a tag; complain.
1290 getSema().Diag(Loc, diag::err_nested_name_spec_non_tag) << T;
1291 return nullptr;
1292 }
1293 }
1294
1295 return cast_or_null<NamedDecl>(TransformDecl(Loc, D));
1296 }
1297
1298 VarDecl *
RebuildExceptionDecl(VarDecl * ExceptionDecl,TypeSourceInfo * Declarator,SourceLocation StartLoc,SourceLocation NameLoc,IdentifierInfo * Name)1299 TemplateInstantiator::RebuildExceptionDecl(VarDecl *ExceptionDecl,
1300 TypeSourceInfo *Declarator,
1301 SourceLocation StartLoc,
1302 SourceLocation NameLoc,
1303 IdentifierInfo *Name) {
1304 VarDecl *Var = inherited::RebuildExceptionDecl(ExceptionDecl, Declarator,
1305 StartLoc, NameLoc, Name);
1306 if (Var)
1307 getSema().CurrentInstantiationScope->InstantiatedLocal(ExceptionDecl, Var);
1308 return Var;
1309 }
1310
RebuildObjCExceptionDecl(VarDecl * ExceptionDecl,TypeSourceInfo * TSInfo,QualType T)1311 VarDecl *TemplateInstantiator::RebuildObjCExceptionDecl(VarDecl *ExceptionDecl,
1312 TypeSourceInfo *TSInfo,
1313 QualType T) {
1314 VarDecl *Var = inherited::RebuildObjCExceptionDecl(ExceptionDecl, TSInfo, T);
1315 if (Var)
1316 getSema().CurrentInstantiationScope->InstantiatedLocal(ExceptionDecl, Var);
1317 return Var;
1318 }
1319
1320 QualType
RebuildElaboratedType(SourceLocation KeywordLoc,ElaboratedTypeKeyword Keyword,NestedNameSpecifierLoc QualifierLoc,QualType T)1321 TemplateInstantiator::RebuildElaboratedType(SourceLocation KeywordLoc,
1322 ElaboratedTypeKeyword Keyword,
1323 NestedNameSpecifierLoc QualifierLoc,
1324 QualType T) {
1325 if (const TagType *TT = T->getAs<TagType>()) {
1326 TagDecl* TD = TT->getDecl();
1327
1328 SourceLocation TagLocation = KeywordLoc;
1329
1330 IdentifierInfo *Id = TD->getIdentifier();
1331
1332 // TODO: should we even warn on struct/class mismatches for this? Seems
1333 // like it's likely to produce a lot of spurious errors.
1334 if (Id && Keyword != ETK_None && Keyword != ETK_Typename) {
1335 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForKeyword(Keyword);
1336 if (!SemaRef.isAcceptableTagRedeclaration(TD, Kind, /*isDefinition*/false,
1337 TagLocation, Id)) {
1338 SemaRef.Diag(TagLocation, diag::err_use_with_wrong_tag)
1339 << Id
1340 << FixItHint::CreateReplacement(SourceRange(TagLocation),
1341 TD->getKindName());
1342 SemaRef.Diag(TD->getLocation(), diag::note_previous_use);
1343 }
1344 }
1345 }
1346
1347 return TreeTransform<TemplateInstantiator>::RebuildElaboratedType(KeywordLoc,
1348 Keyword,
1349 QualifierLoc,
1350 T);
1351 }
1352
TransformTemplateName(CXXScopeSpec & SS,TemplateName Name,SourceLocation NameLoc,QualType ObjectType,NamedDecl * FirstQualifierInScope,bool AllowInjectedClassName)1353 TemplateName TemplateInstantiator::TransformTemplateName(
1354 CXXScopeSpec &SS, TemplateName Name, SourceLocation NameLoc,
1355 QualType ObjectType, NamedDecl *FirstQualifierInScope,
1356 bool AllowInjectedClassName) {
1357 if (TemplateTemplateParmDecl *TTP
1358 = dyn_cast_or_null<TemplateTemplateParmDecl>(Name.getAsTemplateDecl())) {
1359 if (TTP->getDepth() < TemplateArgs.getNumLevels()) {
1360 // If the corresponding template argument is NULL or non-existent, it's
1361 // because we are performing instantiation from explicitly-specified
1362 // template arguments in a function template, but there were some
1363 // arguments left unspecified.
1364 if (!TemplateArgs.hasTemplateArgument(TTP->getDepth(),
1365 TTP->getPosition()))
1366 return Name;
1367
1368 TemplateArgument Arg = TemplateArgs(TTP->getDepth(), TTP->getPosition());
1369
1370 if (TemplateArgs.isRewrite()) {
1371 // We're rewriting the template parameter as a reference to another
1372 // template parameter.
1373 if (Arg.getKind() == TemplateArgument::Pack) {
1374 assert(Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion() &&
1375 "unexpected pack arguments in template rewrite");
1376 Arg = Arg.pack_begin()->getPackExpansionPattern();
1377 }
1378 assert(Arg.getKind() == TemplateArgument::Template &&
1379 "unexpected nontype template argument kind in template rewrite");
1380 return Arg.getAsTemplate();
1381 }
1382
1383 if (TTP->isParameterPack()) {
1384 assert(Arg.getKind() == TemplateArgument::Pack &&
1385 "Missing argument pack");
1386
1387 if (getSema().ArgumentPackSubstitutionIndex == -1) {
1388 // We have the template argument pack to substitute, but we're not
1389 // actually expanding the enclosing pack expansion yet. So, just
1390 // keep the entire argument pack.
1391 return getSema().Context.getSubstTemplateTemplateParmPack(TTP, Arg);
1392 }
1393
1394 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1395 }
1396
1397 TemplateName Template = Arg.getAsTemplate().getNameToSubstitute();
1398 assert(!Template.isNull() && "Null template template argument");
1399 assert(!Template.getAsQualifiedTemplateName() &&
1400 "template decl to substitute is qualified?");
1401
1402 Template = getSema().Context.getSubstTemplateTemplateParm(TTP, Template);
1403 return Template;
1404 }
1405 }
1406
1407 if (SubstTemplateTemplateParmPackStorage *SubstPack
1408 = Name.getAsSubstTemplateTemplateParmPack()) {
1409 if (getSema().ArgumentPackSubstitutionIndex == -1)
1410 return Name;
1411
1412 TemplateArgument Arg = SubstPack->getArgumentPack();
1413 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1414 return Arg.getAsTemplate().getNameToSubstitute();
1415 }
1416
1417 return inherited::TransformTemplateName(SS, Name, NameLoc, ObjectType,
1418 FirstQualifierInScope,
1419 AllowInjectedClassName);
1420 }
1421
1422 ExprResult
TransformPredefinedExpr(PredefinedExpr * E)1423 TemplateInstantiator::TransformPredefinedExpr(PredefinedExpr *E) {
1424 if (!E->isTypeDependent())
1425 return E;
1426
1427 return getSema().BuildPredefinedExpr(E->getLocation(), E->getIdentKind());
1428 }
1429
1430 ExprResult
TransformTemplateParmRefExpr(DeclRefExpr * E,NonTypeTemplateParmDecl * NTTP)1431 TemplateInstantiator::TransformTemplateParmRefExpr(DeclRefExpr *E,
1432 NonTypeTemplateParmDecl *NTTP) {
1433 // If the corresponding template argument is NULL or non-existent, it's
1434 // because we are performing instantiation from explicitly-specified
1435 // template arguments in a function template, but there were some
1436 // arguments left unspecified.
1437 if (!TemplateArgs.hasTemplateArgument(NTTP->getDepth(),
1438 NTTP->getPosition()))
1439 return E;
1440
1441 TemplateArgument Arg = TemplateArgs(NTTP->getDepth(), NTTP->getPosition());
1442
1443 if (TemplateArgs.isRewrite()) {
1444 // We're rewriting the template parameter as a reference to another
1445 // template parameter.
1446 if (Arg.getKind() == TemplateArgument::Pack) {
1447 assert(Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion() &&
1448 "unexpected pack arguments in template rewrite");
1449 Arg = Arg.pack_begin()->getPackExpansionPattern();
1450 }
1451 assert(Arg.getKind() == TemplateArgument::Expression &&
1452 "unexpected nontype template argument kind in template rewrite");
1453 // FIXME: This can lead to the same subexpression appearing multiple times
1454 // in a complete expression.
1455 return Arg.getAsExpr();
1456 }
1457
1458 if (NTTP->isParameterPack()) {
1459 assert(Arg.getKind() == TemplateArgument::Pack &&
1460 "Missing argument pack");
1461
1462 if (getSema().ArgumentPackSubstitutionIndex == -1) {
1463 // We have an argument pack, but we can't select a particular argument
1464 // out of it yet. Therefore, we'll build an expression to hold on to that
1465 // argument pack.
1466 QualType TargetType = SemaRef.SubstType(NTTP->getType(), TemplateArgs,
1467 E->getLocation(),
1468 NTTP->getDeclName());
1469 if (TargetType.isNull())
1470 return ExprError();
1471
1472 QualType ExprType = TargetType.getNonLValueExprType(SemaRef.Context);
1473 if (TargetType->isRecordType())
1474 ExprType.addConst();
1475
1476 return new (SemaRef.Context) SubstNonTypeTemplateParmPackExpr(
1477 ExprType, TargetType->isReferenceType() ? VK_LValue : VK_RValue, NTTP,
1478 E->getLocation(), Arg);
1479 }
1480
1481 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1482 }
1483
1484 return transformNonTypeTemplateParmRef(NTTP, E->getLocation(), Arg);
1485 }
1486
1487 const LoopHintAttr *
TransformLoopHintAttr(const LoopHintAttr * LH)1488 TemplateInstantiator::TransformLoopHintAttr(const LoopHintAttr *LH) {
1489 Expr *TransformedExpr = getDerived().TransformExpr(LH->getValue()).get();
1490
1491 if (TransformedExpr == LH->getValue())
1492 return LH;
1493
1494 // Generate error if there is a problem with the value.
1495 if (getSema().CheckLoopHintExpr(TransformedExpr, LH->getLocation()))
1496 return LH;
1497
1498 // Create new LoopHintValueAttr with integral expression in place of the
1499 // non-type template parameter.
1500 return LoopHintAttr::CreateImplicit(getSema().Context, LH->getOption(),
1501 LH->getState(), TransformedExpr, *LH);
1502 }
1503
transformNonTypeTemplateParmRef(NonTypeTemplateParmDecl * parm,SourceLocation loc,TemplateArgument arg)1504 ExprResult TemplateInstantiator::transformNonTypeTemplateParmRef(
1505 NonTypeTemplateParmDecl *parm,
1506 SourceLocation loc,
1507 TemplateArgument arg) {
1508 ExprResult result;
1509
1510 // Determine the substituted parameter type. We can usually infer this from
1511 // the template argument, but not always.
1512 auto SubstParamType = [&] {
1513 QualType T;
1514 if (parm->isExpandedParameterPack())
1515 T = parm->getExpansionType(SemaRef.ArgumentPackSubstitutionIndex);
1516 else
1517 T = parm->getType();
1518 if (parm->isParameterPack() && isa<PackExpansionType>(T))
1519 T = cast<PackExpansionType>(T)->getPattern();
1520 return SemaRef.SubstType(T, TemplateArgs, loc, parm->getDeclName());
1521 };
1522
1523 bool refParam = false;
1524
1525 // The template argument itself might be an expression, in which case we just
1526 // return that expression. This happens when substituting into an alias
1527 // template.
1528 if (arg.getKind() == TemplateArgument::Expression) {
1529 Expr *argExpr = arg.getAsExpr();
1530 result = argExpr;
1531 if (argExpr->isLValue()) {
1532 if (argExpr->getType()->isRecordType()) {
1533 // Check whether the parameter was actually a reference.
1534 QualType paramType = SubstParamType();
1535 if (paramType.isNull())
1536 return ExprError();
1537 refParam = paramType->isReferenceType();
1538 } else {
1539 refParam = true;
1540 }
1541 }
1542 } else if (arg.getKind() == TemplateArgument::Declaration ||
1543 arg.getKind() == TemplateArgument::NullPtr) {
1544 ValueDecl *VD;
1545 if (arg.getKind() == TemplateArgument::Declaration) {
1546 VD = arg.getAsDecl();
1547
1548 // Find the instantiation of the template argument. This is
1549 // required for nested templates.
1550 VD = cast_or_null<ValueDecl>(
1551 getSema().FindInstantiatedDecl(loc, VD, TemplateArgs));
1552 if (!VD)
1553 return ExprError();
1554 } else {
1555 // Propagate NULL template argument.
1556 VD = nullptr;
1557 }
1558
1559 QualType paramType = VD ? arg.getParamTypeForDecl() : arg.getNullPtrType();
1560 assert(!paramType.isNull() && "type substitution failed for param type");
1561 assert(!paramType->isDependentType() && "param type still dependent");
1562 result = SemaRef.BuildExpressionFromDeclTemplateArgument(arg, paramType, loc);
1563 refParam = paramType->isReferenceType();
1564 } else {
1565 result = SemaRef.BuildExpressionFromIntegralTemplateArgument(arg, loc);
1566 assert(result.isInvalid() ||
1567 SemaRef.Context.hasSameType(result.get()->getType(),
1568 arg.getIntegralType()));
1569 }
1570
1571 if (result.isInvalid())
1572 return ExprError();
1573
1574 Expr *resultExpr = result.get();
1575 return new (SemaRef.Context) SubstNonTypeTemplateParmExpr(
1576 resultExpr->getType(), resultExpr->getValueKind(), loc, parm, refParam,
1577 resultExpr);
1578 }
1579
1580 ExprResult
TransformSubstNonTypeTemplateParmPackExpr(SubstNonTypeTemplateParmPackExpr * E)1581 TemplateInstantiator::TransformSubstNonTypeTemplateParmPackExpr(
1582 SubstNonTypeTemplateParmPackExpr *E) {
1583 if (getSema().ArgumentPackSubstitutionIndex == -1) {
1584 // We aren't expanding the parameter pack, so just return ourselves.
1585 return E;
1586 }
1587
1588 TemplateArgument Arg = E->getArgumentPack();
1589 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1590 return transformNonTypeTemplateParmRef(E->getParameterPack(),
1591 E->getParameterPackLocation(),
1592 Arg);
1593 }
1594
1595 ExprResult
TransformSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr * E)1596 TemplateInstantiator::TransformSubstNonTypeTemplateParmExpr(
1597 SubstNonTypeTemplateParmExpr *E) {
1598 ExprResult SubstReplacement = E->getReplacement();
1599 if (!isa<ConstantExpr>(SubstReplacement.get()))
1600 SubstReplacement = TransformExpr(E->getReplacement());
1601 if (SubstReplacement.isInvalid())
1602 return true;
1603 QualType SubstType = TransformType(E->getParameterType(getSema().Context));
1604 if (SubstType.isNull())
1605 return true;
1606 // The type may have been previously dependent and not now, which means we
1607 // might have to implicit cast the argument to the new type, for example:
1608 // template<auto T, decltype(T) U>
1609 // concept C = sizeof(U) == 4;
1610 // void foo() requires C<2, 'a'> { }
1611 // When normalizing foo(), we first form the normalized constraints of C:
1612 // AtomicExpr(sizeof(U) == 4,
1613 // U=SubstNonTypeTemplateParmExpr(Param=U,
1614 // Expr=DeclRef(U),
1615 // Type=decltype(T)))
1616 // Then we substitute T = 2, U = 'a' into the parameter mapping, and need to
1617 // produce:
1618 // AtomicExpr(sizeof(U) == 4,
1619 // U=SubstNonTypeTemplateParmExpr(Param=U,
1620 // Expr=ImpCast(
1621 // decltype(2),
1622 // SubstNTTPE(Param=U, Expr='a',
1623 // Type=char)),
1624 // Type=decltype(2)))
1625 // The call to CheckTemplateArgument here produces the ImpCast.
1626 TemplateArgument Converted;
1627 if (SemaRef.CheckTemplateArgument(E->getParameter(), SubstType,
1628 SubstReplacement.get(),
1629 Converted).isInvalid())
1630 return true;
1631 return transformNonTypeTemplateParmRef(E->getParameter(),
1632 E->getExprLoc(), Converted);
1633 }
1634
RebuildVarDeclRefExpr(VarDecl * PD,SourceLocation Loc)1635 ExprResult TemplateInstantiator::RebuildVarDeclRefExpr(VarDecl *PD,
1636 SourceLocation Loc) {
1637 DeclarationNameInfo NameInfo(PD->getDeclName(), Loc);
1638 return getSema().BuildDeclarationNameExpr(CXXScopeSpec(), NameInfo, PD);
1639 }
1640
1641 ExprResult
TransformFunctionParmPackExpr(FunctionParmPackExpr * E)1642 TemplateInstantiator::TransformFunctionParmPackExpr(FunctionParmPackExpr *E) {
1643 if (getSema().ArgumentPackSubstitutionIndex != -1) {
1644 // We can expand this parameter pack now.
1645 VarDecl *D = E->getExpansion(getSema().ArgumentPackSubstitutionIndex);
1646 VarDecl *VD = cast_or_null<VarDecl>(TransformDecl(E->getExprLoc(), D));
1647 if (!VD)
1648 return ExprError();
1649 return RebuildVarDeclRefExpr(VD, E->getExprLoc());
1650 }
1651
1652 QualType T = TransformType(E->getType());
1653 if (T.isNull())
1654 return ExprError();
1655
1656 // Transform each of the parameter expansions into the corresponding
1657 // parameters in the instantiation of the function decl.
1658 SmallVector<VarDecl *, 8> Vars;
1659 Vars.reserve(E->getNumExpansions());
1660 for (FunctionParmPackExpr::iterator I = E->begin(), End = E->end();
1661 I != End; ++I) {
1662 VarDecl *D = cast_or_null<VarDecl>(TransformDecl(E->getExprLoc(), *I));
1663 if (!D)
1664 return ExprError();
1665 Vars.push_back(D);
1666 }
1667
1668 auto *PackExpr =
1669 FunctionParmPackExpr::Create(getSema().Context, T, E->getParameterPack(),
1670 E->getParameterPackLocation(), Vars);
1671 getSema().MarkFunctionParmPackReferenced(PackExpr);
1672 return PackExpr;
1673 }
1674
1675 ExprResult
TransformFunctionParmPackRefExpr(DeclRefExpr * E,VarDecl * PD)1676 TemplateInstantiator::TransformFunctionParmPackRefExpr(DeclRefExpr *E,
1677 VarDecl *PD) {
1678 typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack;
1679 llvm::PointerUnion<Decl *, DeclArgumentPack *> *Found
1680 = getSema().CurrentInstantiationScope->findInstantiationOf(PD);
1681 assert(Found && "no instantiation for parameter pack");
1682
1683 Decl *TransformedDecl;
1684 if (DeclArgumentPack *Pack = Found->dyn_cast<DeclArgumentPack *>()) {
1685 // If this is a reference to a function parameter pack which we can
1686 // substitute but can't yet expand, build a FunctionParmPackExpr for it.
1687 if (getSema().ArgumentPackSubstitutionIndex == -1) {
1688 QualType T = TransformType(E->getType());
1689 if (T.isNull())
1690 return ExprError();
1691 auto *PackExpr = FunctionParmPackExpr::Create(getSema().Context, T, PD,
1692 E->getExprLoc(), *Pack);
1693 getSema().MarkFunctionParmPackReferenced(PackExpr);
1694 return PackExpr;
1695 }
1696
1697 TransformedDecl = (*Pack)[getSema().ArgumentPackSubstitutionIndex];
1698 } else {
1699 TransformedDecl = Found->get<Decl*>();
1700 }
1701
1702 // We have either an unexpanded pack or a specific expansion.
1703 return RebuildVarDeclRefExpr(cast<VarDecl>(TransformedDecl), E->getExprLoc());
1704 }
1705
1706 ExprResult
TransformDeclRefExpr(DeclRefExpr * E)1707 TemplateInstantiator::TransformDeclRefExpr(DeclRefExpr *E) {
1708 NamedDecl *D = E->getDecl();
1709
1710 // Handle references to non-type template parameters and non-type template
1711 // parameter packs.
1712 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(D)) {
1713 if (NTTP->getDepth() < TemplateArgs.getNumLevels())
1714 return TransformTemplateParmRefExpr(E, NTTP);
1715
1716 // We have a non-type template parameter that isn't fully substituted;
1717 // FindInstantiatedDecl will find it in the local instantiation scope.
1718 }
1719
1720 // Handle references to function parameter packs.
1721 if (VarDecl *PD = dyn_cast<VarDecl>(D))
1722 if (PD->isParameterPack())
1723 return TransformFunctionParmPackRefExpr(E, PD);
1724
1725 return TreeTransform<TemplateInstantiator>::TransformDeclRefExpr(E);
1726 }
1727
TransformCXXDefaultArgExpr(CXXDefaultArgExpr * E)1728 ExprResult TemplateInstantiator::TransformCXXDefaultArgExpr(
1729 CXXDefaultArgExpr *E) {
1730 assert(!cast<FunctionDecl>(E->getParam()->getDeclContext())->
1731 getDescribedFunctionTemplate() &&
1732 "Default arg expressions are never formed in dependent cases.");
1733 return SemaRef.BuildCXXDefaultArgExpr(E->getUsedLocation(),
1734 cast<FunctionDecl>(E->getParam()->getDeclContext()),
1735 E->getParam());
1736 }
1737
1738 template<typename Fn>
TransformFunctionProtoType(TypeLocBuilder & TLB,FunctionProtoTypeLoc TL,CXXRecordDecl * ThisContext,Qualifiers ThisTypeQuals,Fn TransformExceptionSpec)1739 QualType TemplateInstantiator::TransformFunctionProtoType(TypeLocBuilder &TLB,
1740 FunctionProtoTypeLoc TL,
1741 CXXRecordDecl *ThisContext,
1742 Qualifiers ThisTypeQuals,
1743 Fn TransformExceptionSpec) {
1744 // We need a local instantiation scope for this function prototype.
1745 LocalInstantiationScope Scope(SemaRef, /*CombineWithOuterScope=*/true);
1746 return inherited::TransformFunctionProtoType(
1747 TLB, TL, ThisContext, ThisTypeQuals, TransformExceptionSpec);
1748 }
1749
1750 ParmVarDecl *
TransformFunctionTypeParam(ParmVarDecl * OldParm,int indexAdjustment,Optional<unsigned> NumExpansions,bool ExpectParameterPack)1751 TemplateInstantiator::TransformFunctionTypeParam(ParmVarDecl *OldParm,
1752 int indexAdjustment,
1753 Optional<unsigned> NumExpansions,
1754 bool ExpectParameterPack) {
1755 auto NewParm =
1756 SemaRef.SubstParmVarDecl(OldParm, TemplateArgs, indexAdjustment,
1757 NumExpansions, ExpectParameterPack);
1758 if (NewParm && SemaRef.getLangOpts().OpenCL)
1759 SemaRef.deduceOpenCLAddressSpace(NewParm);
1760 return NewParm;
1761 }
1762
1763 QualType
TransformTemplateTypeParmType(TypeLocBuilder & TLB,TemplateTypeParmTypeLoc TL)1764 TemplateInstantiator::TransformTemplateTypeParmType(TypeLocBuilder &TLB,
1765 TemplateTypeParmTypeLoc TL) {
1766 const TemplateTypeParmType *T = TL.getTypePtr();
1767 if (T->getDepth() < TemplateArgs.getNumLevels()) {
1768 // Replace the template type parameter with its corresponding
1769 // template argument.
1770
1771 // If the corresponding template argument is NULL or doesn't exist, it's
1772 // because we are performing instantiation from explicitly-specified
1773 // template arguments in a function template class, but there were some
1774 // arguments left unspecified.
1775 if (!TemplateArgs.hasTemplateArgument(T->getDepth(), T->getIndex())) {
1776 TemplateTypeParmTypeLoc NewTL
1777 = TLB.push<TemplateTypeParmTypeLoc>(TL.getType());
1778 NewTL.setNameLoc(TL.getNameLoc());
1779 return TL.getType();
1780 }
1781
1782 TemplateArgument Arg = TemplateArgs(T->getDepth(), T->getIndex());
1783
1784 if (TemplateArgs.isRewrite()) {
1785 // We're rewriting the template parameter as a reference to another
1786 // template parameter.
1787 if (Arg.getKind() == TemplateArgument::Pack) {
1788 assert(Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion() &&
1789 "unexpected pack arguments in template rewrite");
1790 Arg = Arg.pack_begin()->getPackExpansionPattern();
1791 }
1792 assert(Arg.getKind() == TemplateArgument::Type &&
1793 "unexpected nontype template argument kind in template rewrite");
1794 QualType NewT = Arg.getAsType();
1795 assert(isa<TemplateTypeParmType>(NewT) &&
1796 "type parm not rewritten to type parm");
1797 auto NewTL = TLB.push<TemplateTypeParmTypeLoc>(NewT);
1798 NewTL.setNameLoc(TL.getNameLoc());
1799 return NewT;
1800 }
1801
1802 if (T->isParameterPack()) {
1803 assert(Arg.getKind() == TemplateArgument::Pack &&
1804 "Missing argument pack");
1805
1806 if (getSema().ArgumentPackSubstitutionIndex == -1) {
1807 // We have the template argument pack, but we're not expanding the
1808 // enclosing pack expansion yet. Just save the template argument
1809 // pack for later substitution.
1810 QualType Result
1811 = getSema().Context.getSubstTemplateTypeParmPackType(T, Arg);
1812 SubstTemplateTypeParmPackTypeLoc NewTL
1813 = TLB.push<SubstTemplateTypeParmPackTypeLoc>(Result);
1814 NewTL.setNameLoc(TL.getNameLoc());
1815 return Result;
1816 }
1817
1818 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1819 }
1820
1821 assert(Arg.getKind() == TemplateArgument::Type &&
1822 "Template argument kind mismatch");
1823
1824 QualType Replacement = Arg.getAsType();
1825
1826 // TODO: only do this uniquing once, at the start of instantiation.
1827 QualType Result
1828 = getSema().Context.getSubstTemplateTypeParmType(T, Replacement);
1829 SubstTemplateTypeParmTypeLoc NewTL
1830 = TLB.push<SubstTemplateTypeParmTypeLoc>(Result);
1831 NewTL.setNameLoc(TL.getNameLoc());
1832 return Result;
1833 }
1834
1835 // The template type parameter comes from an inner template (e.g.,
1836 // the template parameter list of a member template inside the
1837 // template we are instantiating). Create a new template type
1838 // parameter with the template "level" reduced by one.
1839 TemplateTypeParmDecl *NewTTPDecl = nullptr;
1840 if (TemplateTypeParmDecl *OldTTPDecl = T->getDecl())
1841 NewTTPDecl = cast_or_null<TemplateTypeParmDecl>(
1842 TransformDecl(TL.getNameLoc(), OldTTPDecl));
1843
1844 QualType Result = getSema().Context.getTemplateTypeParmType(
1845 T->getDepth() - TemplateArgs.getNumSubstitutedLevels(), T->getIndex(),
1846 T->isParameterPack(), NewTTPDecl);
1847 TemplateTypeParmTypeLoc NewTL = TLB.push<TemplateTypeParmTypeLoc>(Result);
1848 NewTL.setNameLoc(TL.getNameLoc());
1849 return Result;
1850 }
1851
1852 QualType
TransformSubstTemplateTypeParmPackType(TypeLocBuilder & TLB,SubstTemplateTypeParmPackTypeLoc TL)1853 TemplateInstantiator::TransformSubstTemplateTypeParmPackType(
1854 TypeLocBuilder &TLB,
1855 SubstTemplateTypeParmPackTypeLoc TL) {
1856 if (getSema().ArgumentPackSubstitutionIndex == -1) {
1857 // We aren't expanding the parameter pack, so just return ourselves.
1858 SubstTemplateTypeParmPackTypeLoc NewTL
1859 = TLB.push<SubstTemplateTypeParmPackTypeLoc>(TL.getType());
1860 NewTL.setNameLoc(TL.getNameLoc());
1861 return TL.getType();
1862 }
1863
1864 TemplateArgument Arg = TL.getTypePtr()->getArgumentPack();
1865 Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
1866 QualType Result = Arg.getAsType();
1867
1868 Result = getSema().Context.getSubstTemplateTypeParmType(
1869 TL.getTypePtr()->getReplacedParameter(),
1870 Result);
1871 SubstTemplateTypeParmTypeLoc NewTL
1872 = TLB.push<SubstTemplateTypeParmTypeLoc>(Result);
1873 NewTL.setNameLoc(TL.getNameLoc());
1874 return Result;
1875 }
1876
1877 template<typename EntityPrinter>
1878 static concepts::Requirement::SubstitutionDiagnostic *
createSubstDiag(Sema & S,TemplateDeductionInfo & Info,EntityPrinter Printer)1879 createSubstDiag(Sema &S, TemplateDeductionInfo &Info, EntityPrinter Printer) {
1880 SmallString<128> Message;
1881 SourceLocation ErrorLoc;
1882 if (Info.hasSFINAEDiagnostic()) {
1883 PartialDiagnosticAt PDA(SourceLocation(),
1884 PartialDiagnostic::NullDiagnostic{});
1885 Info.takeSFINAEDiagnostic(PDA);
1886 PDA.second.EmitToString(S.getDiagnostics(), Message);
1887 ErrorLoc = PDA.first;
1888 } else {
1889 ErrorLoc = Info.getLocation();
1890 }
1891 char *MessageBuf = new (S.Context) char[Message.size()];
1892 std::copy(Message.begin(), Message.end(), MessageBuf);
1893 SmallString<128> Entity;
1894 llvm::raw_svector_ostream OS(Entity);
1895 Printer(OS);
1896 char *EntityBuf = new (S.Context) char[Entity.size()];
1897 std::copy(Entity.begin(), Entity.end(), EntityBuf);
1898 return new (S.Context) concepts::Requirement::SubstitutionDiagnostic{
1899 StringRef(EntityBuf, Entity.size()), ErrorLoc,
1900 StringRef(MessageBuf, Message.size())};
1901 }
1902
1903 concepts::TypeRequirement *
TransformTypeRequirement(concepts::TypeRequirement * Req)1904 TemplateInstantiator::TransformTypeRequirement(concepts::TypeRequirement *Req) {
1905 if (!Req->isDependent() && !AlwaysRebuild())
1906 return Req;
1907 if (Req->isSubstitutionFailure()) {
1908 if (AlwaysRebuild())
1909 return RebuildTypeRequirement(
1910 Req->getSubstitutionDiagnostic());
1911 return Req;
1912 }
1913
1914 Sema::SFINAETrap Trap(SemaRef);
1915 TemplateDeductionInfo Info(Req->getType()->getTypeLoc().getBeginLoc());
1916 Sema::InstantiatingTemplate TypeInst(SemaRef,
1917 Req->getType()->getTypeLoc().getBeginLoc(), Req, Info,
1918 Req->getType()->getTypeLoc().getSourceRange());
1919 if (TypeInst.isInvalid())
1920 return nullptr;
1921 TypeSourceInfo *TransType = TransformType(Req->getType());
1922 if (!TransType || Trap.hasErrorOccurred())
1923 return RebuildTypeRequirement(createSubstDiag(SemaRef, Info,
1924 [&] (llvm::raw_ostream& OS) {
1925 Req->getType()->getType().print(OS, SemaRef.getPrintingPolicy());
1926 }));
1927 return RebuildTypeRequirement(TransType);
1928 }
1929
1930 concepts::ExprRequirement *
TransformExprRequirement(concepts::ExprRequirement * Req)1931 TemplateInstantiator::TransformExprRequirement(concepts::ExprRequirement *Req) {
1932 if (!Req->isDependent() && !AlwaysRebuild())
1933 return Req;
1934
1935 Sema::SFINAETrap Trap(SemaRef);
1936 TemplateDeductionInfo Info(Req->getExpr()->getBeginLoc());
1937
1938 llvm::PointerUnion<Expr *, concepts::Requirement::SubstitutionDiagnostic *>
1939 TransExpr;
1940 if (Req->isExprSubstitutionFailure())
1941 TransExpr = Req->getExprSubstitutionDiagnostic();
1942 else {
1943 Sema::InstantiatingTemplate ExprInst(SemaRef, Req->getExpr()->getBeginLoc(),
1944 Req, Info,
1945 Req->getExpr()->getSourceRange());
1946 if (ExprInst.isInvalid())
1947 return nullptr;
1948 ExprResult TransExprRes = TransformExpr(Req->getExpr());
1949 if (TransExprRes.isInvalid() || Trap.hasErrorOccurred())
1950 TransExpr = createSubstDiag(SemaRef, Info,
1951 [&] (llvm::raw_ostream& OS) {
1952 Req->getExpr()->printPretty(OS, nullptr,
1953 SemaRef.getPrintingPolicy());
1954 });
1955 else
1956 TransExpr = TransExprRes.get();
1957 }
1958
1959 llvm::Optional<concepts::ExprRequirement::ReturnTypeRequirement> TransRetReq;
1960 const auto &RetReq = Req->getReturnTypeRequirement();
1961 if (RetReq.isEmpty())
1962 TransRetReq.emplace();
1963 else if (RetReq.isSubstitutionFailure())
1964 TransRetReq.emplace(RetReq.getSubstitutionDiagnostic());
1965 else if (RetReq.isTypeConstraint()) {
1966 TemplateParameterList *OrigTPL =
1967 RetReq.getTypeConstraintTemplateParameterList();
1968 Sema::InstantiatingTemplate TPLInst(SemaRef, OrigTPL->getTemplateLoc(),
1969 Req, Info, OrigTPL->getSourceRange());
1970 if (TPLInst.isInvalid())
1971 return nullptr;
1972 TemplateParameterList *TPL =
1973 TransformTemplateParameterList(OrigTPL);
1974 if (!TPL)
1975 TransRetReq.emplace(createSubstDiag(SemaRef, Info,
1976 [&] (llvm::raw_ostream& OS) {
1977 RetReq.getTypeConstraint()->getImmediatelyDeclaredConstraint()
1978 ->printPretty(OS, nullptr, SemaRef.getPrintingPolicy());
1979 }));
1980 else {
1981 TPLInst.Clear();
1982 TransRetReq.emplace(TPL);
1983 }
1984 }
1985 assert(TransRetReq.hasValue() &&
1986 "All code paths leading here must set TransRetReq");
1987 if (Expr *E = TransExpr.dyn_cast<Expr *>())
1988 return RebuildExprRequirement(E, Req->isSimple(), Req->getNoexceptLoc(),
1989 std::move(*TransRetReq));
1990 return RebuildExprRequirement(
1991 TransExpr.get<concepts::Requirement::SubstitutionDiagnostic *>(),
1992 Req->isSimple(), Req->getNoexceptLoc(), std::move(*TransRetReq));
1993 }
1994
1995 concepts::NestedRequirement *
TransformNestedRequirement(concepts::NestedRequirement * Req)1996 TemplateInstantiator::TransformNestedRequirement(
1997 concepts::NestedRequirement *Req) {
1998 if (!Req->isDependent() && !AlwaysRebuild())
1999 return Req;
2000 if (Req->isSubstitutionFailure()) {
2001 if (AlwaysRebuild())
2002 return RebuildNestedRequirement(
2003 Req->getSubstitutionDiagnostic());
2004 return Req;
2005 }
2006 Sema::InstantiatingTemplate ReqInst(SemaRef,
2007 Req->getConstraintExpr()->getBeginLoc(), Req,
2008 Sema::InstantiatingTemplate::ConstraintsCheck{},
2009 Req->getConstraintExpr()->getSourceRange());
2010
2011 ExprResult TransConstraint;
2012 TemplateDeductionInfo Info(Req->getConstraintExpr()->getBeginLoc());
2013 {
2014 EnterExpressionEvaluationContext ContextRAII(
2015 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
2016 Sema::SFINAETrap Trap(SemaRef);
2017 Sema::InstantiatingTemplate ConstrInst(SemaRef,
2018 Req->getConstraintExpr()->getBeginLoc(), Req, Info,
2019 Req->getConstraintExpr()->getSourceRange());
2020 if (ConstrInst.isInvalid())
2021 return nullptr;
2022 TransConstraint = TransformExpr(Req->getConstraintExpr());
2023 if (TransConstraint.isInvalid() || Trap.hasErrorOccurred())
2024 return RebuildNestedRequirement(createSubstDiag(SemaRef, Info,
2025 [&] (llvm::raw_ostream& OS) {
2026 Req->getConstraintExpr()->printPretty(OS, nullptr,
2027 SemaRef.getPrintingPolicy());
2028 }));
2029 }
2030 return RebuildNestedRequirement(TransConstraint.get());
2031 }
2032
2033
2034 /// Perform substitution on the type T with a given set of template
2035 /// arguments.
2036 ///
2037 /// This routine substitutes the given template arguments into the
2038 /// type T and produces the instantiated type.
2039 ///
2040 /// \param T the type into which the template arguments will be
2041 /// substituted. If this type is not dependent, it will be returned
2042 /// immediately.
2043 ///
2044 /// \param Args the template arguments that will be
2045 /// substituted for the top-level template parameters within T.
2046 ///
2047 /// \param Loc the location in the source code where this substitution
2048 /// is being performed. It will typically be the location of the
2049 /// declarator (if we're instantiating the type of some declaration)
2050 /// or the location of the type in the source code (if, e.g., we're
2051 /// instantiating the type of a cast expression).
2052 ///
2053 /// \param Entity the name of the entity associated with a declaration
2054 /// being instantiated (if any). May be empty to indicate that there
2055 /// is no such entity (if, e.g., this is a type that occurs as part of
2056 /// a cast expression) or that the entity has no name (e.g., an
2057 /// unnamed function parameter).
2058 ///
2059 /// \param AllowDeducedTST Whether a DeducedTemplateSpecializationType is
2060 /// acceptable as the top level type of the result.
2061 ///
2062 /// \returns If the instantiation succeeds, the instantiated
2063 /// type. Otherwise, produces diagnostics and returns a NULL type.
SubstType(TypeSourceInfo * T,const MultiLevelTemplateArgumentList & Args,SourceLocation Loc,DeclarationName Entity,bool AllowDeducedTST)2064 TypeSourceInfo *Sema::SubstType(TypeSourceInfo *T,
2065 const MultiLevelTemplateArgumentList &Args,
2066 SourceLocation Loc,
2067 DeclarationName Entity,
2068 bool AllowDeducedTST) {
2069 assert(!CodeSynthesisContexts.empty() &&
2070 "Cannot perform an instantiation without some context on the "
2071 "instantiation stack");
2072
2073 if (!T->getType()->isInstantiationDependentType() &&
2074 !T->getType()->isVariablyModifiedType())
2075 return T;
2076
2077 TemplateInstantiator Instantiator(*this, Args, Loc, Entity);
2078 return AllowDeducedTST ? Instantiator.TransformTypeWithDeducedTST(T)
2079 : Instantiator.TransformType(T);
2080 }
2081
SubstType(TypeLoc TL,const MultiLevelTemplateArgumentList & Args,SourceLocation Loc,DeclarationName Entity)2082 TypeSourceInfo *Sema::SubstType(TypeLoc TL,
2083 const MultiLevelTemplateArgumentList &Args,
2084 SourceLocation Loc,
2085 DeclarationName Entity) {
2086 assert(!CodeSynthesisContexts.empty() &&
2087 "Cannot perform an instantiation without some context on the "
2088 "instantiation stack");
2089
2090 if (TL.getType().isNull())
2091 return nullptr;
2092
2093 if (!TL.getType()->isInstantiationDependentType() &&
2094 !TL.getType()->isVariablyModifiedType()) {
2095 // FIXME: Make a copy of the TypeLoc data here, so that we can
2096 // return a new TypeSourceInfo. Inefficient!
2097 TypeLocBuilder TLB;
2098 TLB.pushFullCopy(TL);
2099 return TLB.getTypeSourceInfo(Context, TL.getType());
2100 }
2101
2102 TemplateInstantiator Instantiator(*this, Args, Loc, Entity);
2103 TypeLocBuilder TLB;
2104 TLB.reserve(TL.getFullDataSize());
2105 QualType Result = Instantiator.TransformType(TLB, TL);
2106 if (Result.isNull())
2107 return nullptr;
2108
2109 return TLB.getTypeSourceInfo(Context, Result);
2110 }
2111
2112 /// Deprecated form of the above.
SubstType(QualType T,const MultiLevelTemplateArgumentList & TemplateArgs,SourceLocation Loc,DeclarationName Entity)2113 QualType Sema::SubstType(QualType T,
2114 const MultiLevelTemplateArgumentList &TemplateArgs,
2115 SourceLocation Loc, DeclarationName Entity) {
2116 assert(!CodeSynthesisContexts.empty() &&
2117 "Cannot perform an instantiation without some context on the "
2118 "instantiation stack");
2119
2120 // If T is not a dependent type or a variably-modified type, there
2121 // is nothing to do.
2122 if (!T->isInstantiationDependentType() && !T->isVariablyModifiedType())
2123 return T;
2124
2125 TemplateInstantiator Instantiator(*this, TemplateArgs, Loc, Entity);
2126 return Instantiator.TransformType(T);
2127 }
2128
NeedsInstantiationAsFunctionType(TypeSourceInfo * T)2129 static bool NeedsInstantiationAsFunctionType(TypeSourceInfo *T) {
2130 if (T->getType()->isInstantiationDependentType() ||
2131 T->getType()->isVariablyModifiedType())
2132 return true;
2133
2134 TypeLoc TL = T->getTypeLoc().IgnoreParens();
2135 if (!TL.getAs<FunctionProtoTypeLoc>())
2136 return false;
2137
2138 FunctionProtoTypeLoc FP = TL.castAs<FunctionProtoTypeLoc>();
2139 for (ParmVarDecl *P : FP.getParams()) {
2140 // This must be synthesized from a typedef.
2141 if (!P) continue;
2142
2143 // If there are any parameters, a new TypeSourceInfo that refers to the
2144 // instantiated parameters must be built.
2145 return true;
2146 }
2147
2148 return false;
2149 }
2150
2151 /// A form of SubstType intended specifically for instantiating the
2152 /// type of a FunctionDecl. Its purpose is solely to force the
2153 /// instantiation of default-argument expressions and to avoid
2154 /// instantiating an exception-specification.
SubstFunctionDeclType(TypeSourceInfo * T,const MultiLevelTemplateArgumentList & Args,SourceLocation Loc,DeclarationName Entity,CXXRecordDecl * ThisContext,Qualifiers ThisTypeQuals)2155 TypeSourceInfo *Sema::SubstFunctionDeclType(TypeSourceInfo *T,
2156 const MultiLevelTemplateArgumentList &Args,
2157 SourceLocation Loc,
2158 DeclarationName Entity,
2159 CXXRecordDecl *ThisContext,
2160 Qualifiers ThisTypeQuals) {
2161 assert(!CodeSynthesisContexts.empty() &&
2162 "Cannot perform an instantiation without some context on the "
2163 "instantiation stack");
2164
2165 if (!NeedsInstantiationAsFunctionType(T))
2166 return T;
2167
2168 TemplateInstantiator Instantiator(*this, Args, Loc, Entity);
2169
2170 TypeLocBuilder TLB;
2171
2172 TypeLoc TL = T->getTypeLoc();
2173 TLB.reserve(TL.getFullDataSize());
2174
2175 QualType Result;
2176
2177 if (FunctionProtoTypeLoc Proto =
2178 TL.IgnoreParens().getAs<FunctionProtoTypeLoc>()) {
2179 // Instantiate the type, other than its exception specification. The
2180 // exception specification is instantiated in InitFunctionInstantiation
2181 // once we've built the FunctionDecl.
2182 // FIXME: Set the exception specification to EST_Uninstantiated here,
2183 // instead of rebuilding the function type again later.
2184 Result = Instantiator.TransformFunctionProtoType(
2185 TLB, Proto, ThisContext, ThisTypeQuals,
2186 [](FunctionProtoType::ExceptionSpecInfo &ESI,
2187 bool &Changed) { return false; });
2188 } else {
2189 Result = Instantiator.TransformType(TLB, TL);
2190 }
2191 if (Result.isNull())
2192 return nullptr;
2193
2194 return TLB.getTypeSourceInfo(Context, Result);
2195 }
2196
SubstExceptionSpec(SourceLocation Loc,FunctionProtoType::ExceptionSpecInfo & ESI,SmallVectorImpl<QualType> & ExceptionStorage,const MultiLevelTemplateArgumentList & Args)2197 bool Sema::SubstExceptionSpec(SourceLocation Loc,
2198 FunctionProtoType::ExceptionSpecInfo &ESI,
2199 SmallVectorImpl<QualType> &ExceptionStorage,
2200 const MultiLevelTemplateArgumentList &Args) {
2201 assert(ESI.Type != EST_Uninstantiated);
2202
2203 bool Changed = false;
2204 TemplateInstantiator Instantiator(*this, Args, Loc, DeclarationName());
2205 return Instantiator.TransformExceptionSpec(Loc, ESI, ExceptionStorage,
2206 Changed);
2207 }
2208
SubstExceptionSpec(FunctionDecl * New,const FunctionProtoType * Proto,const MultiLevelTemplateArgumentList & Args)2209 void Sema::SubstExceptionSpec(FunctionDecl *New, const FunctionProtoType *Proto,
2210 const MultiLevelTemplateArgumentList &Args) {
2211 FunctionProtoType::ExceptionSpecInfo ESI =
2212 Proto->getExtProtoInfo().ExceptionSpec;
2213
2214 SmallVector<QualType, 4> ExceptionStorage;
2215 if (SubstExceptionSpec(New->getTypeSourceInfo()->getTypeLoc().getEndLoc(),
2216 ESI, ExceptionStorage, Args))
2217 // On error, recover by dropping the exception specification.
2218 ESI.Type = EST_None;
2219
2220 UpdateExceptionSpec(New, ESI);
2221 }
2222
2223 namespace {
2224
2225 struct GetContainedInventedTypeParmVisitor :
2226 public TypeVisitor<GetContainedInventedTypeParmVisitor,
2227 TemplateTypeParmDecl *> {
2228 using TypeVisitor<GetContainedInventedTypeParmVisitor,
2229 TemplateTypeParmDecl *>::Visit;
2230
Visit__anondae4e9c10811::GetContainedInventedTypeParmVisitor2231 TemplateTypeParmDecl *Visit(QualType T) {
2232 if (T.isNull())
2233 return nullptr;
2234 return Visit(T.getTypePtr());
2235 }
2236 // The deduced type itself.
VisitTemplateTypeParmType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2237 TemplateTypeParmDecl *VisitTemplateTypeParmType(
2238 const TemplateTypeParmType *T) {
2239 if (!T->getDecl() || !T->getDecl()->isImplicit())
2240 return nullptr;
2241 return T->getDecl();
2242 }
2243
2244 // Only these types can contain 'auto' types, and subsequently be replaced
2245 // by references to invented parameters.
2246
VisitElaboratedType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2247 TemplateTypeParmDecl *VisitElaboratedType(const ElaboratedType *T) {
2248 return Visit(T->getNamedType());
2249 }
2250
VisitPointerType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2251 TemplateTypeParmDecl *VisitPointerType(const PointerType *T) {
2252 return Visit(T->getPointeeType());
2253 }
2254
VisitBlockPointerType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2255 TemplateTypeParmDecl *VisitBlockPointerType(const BlockPointerType *T) {
2256 return Visit(T->getPointeeType());
2257 }
2258
VisitReferenceType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2259 TemplateTypeParmDecl *VisitReferenceType(const ReferenceType *T) {
2260 return Visit(T->getPointeeTypeAsWritten());
2261 }
2262
VisitMemberPointerType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2263 TemplateTypeParmDecl *VisitMemberPointerType(const MemberPointerType *T) {
2264 return Visit(T->getPointeeType());
2265 }
2266
VisitArrayType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2267 TemplateTypeParmDecl *VisitArrayType(const ArrayType *T) {
2268 return Visit(T->getElementType());
2269 }
2270
VisitDependentSizedExtVectorType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2271 TemplateTypeParmDecl *VisitDependentSizedExtVectorType(
2272 const DependentSizedExtVectorType *T) {
2273 return Visit(T->getElementType());
2274 }
2275
VisitVectorType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2276 TemplateTypeParmDecl *VisitVectorType(const VectorType *T) {
2277 return Visit(T->getElementType());
2278 }
2279
VisitFunctionProtoType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2280 TemplateTypeParmDecl *VisitFunctionProtoType(const FunctionProtoType *T) {
2281 return VisitFunctionType(T);
2282 }
2283
VisitFunctionType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2284 TemplateTypeParmDecl *VisitFunctionType(const FunctionType *T) {
2285 return Visit(T->getReturnType());
2286 }
2287
VisitParenType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2288 TemplateTypeParmDecl *VisitParenType(const ParenType *T) {
2289 return Visit(T->getInnerType());
2290 }
2291
VisitAttributedType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2292 TemplateTypeParmDecl *VisitAttributedType(const AttributedType *T) {
2293 return Visit(T->getModifiedType());
2294 }
2295
VisitMacroQualifiedType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2296 TemplateTypeParmDecl *VisitMacroQualifiedType(const MacroQualifiedType *T) {
2297 return Visit(T->getUnderlyingType());
2298 }
2299
VisitAdjustedType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2300 TemplateTypeParmDecl *VisitAdjustedType(const AdjustedType *T) {
2301 return Visit(T->getOriginalType());
2302 }
2303
VisitPackExpansionType__anondae4e9c10811::GetContainedInventedTypeParmVisitor2304 TemplateTypeParmDecl *VisitPackExpansionType(const PackExpansionType *T) {
2305 return Visit(T->getPattern());
2306 }
2307 };
2308
2309 } // namespace
2310
SubstParmVarDecl(ParmVarDecl * OldParm,const MultiLevelTemplateArgumentList & TemplateArgs,int indexAdjustment,Optional<unsigned> NumExpansions,bool ExpectParameterPack)2311 ParmVarDecl *Sema::SubstParmVarDecl(ParmVarDecl *OldParm,
2312 const MultiLevelTemplateArgumentList &TemplateArgs,
2313 int indexAdjustment,
2314 Optional<unsigned> NumExpansions,
2315 bool ExpectParameterPack) {
2316 TypeSourceInfo *OldDI = OldParm->getTypeSourceInfo();
2317 TypeSourceInfo *NewDI = nullptr;
2318
2319 TypeLoc OldTL = OldDI->getTypeLoc();
2320 if (PackExpansionTypeLoc ExpansionTL = OldTL.getAs<PackExpansionTypeLoc>()) {
2321
2322 // We have a function parameter pack. Substitute into the pattern of the
2323 // expansion.
2324 NewDI = SubstType(ExpansionTL.getPatternLoc(), TemplateArgs,
2325 OldParm->getLocation(), OldParm->getDeclName());
2326 if (!NewDI)
2327 return nullptr;
2328
2329 if (NewDI->getType()->containsUnexpandedParameterPack()) {
2330 // We still have unexpanded parameter packs, which means that
2331 // our function parameter is still a function parameter pack.
2332 // Therefore, make its type a pack expansion type.
2333 NewDI = CheckPackExpansion(NewDI, ExpansionTL.getEllipsisLoc(),
2334 NumExpansions);
2335 } else if (ExpectParameterPack) {
2336 // We expected to get a parameter pack but didn't (because the type
2337 // itself is not a pack expansion type), so complain. This can occur when
2338 // the substitution goes through an alias template that "loses" the
2339 // pack expansion.
2340 Diag(OldParm->getLocation(),
2341 diag::err_function_parameter_pack_without_parameter_packs)
2342 << NewDI->getType();
2343 return nullptr;
2344 }
2345 } else {
2346 NewDI = SubstType(OldDI, TemplateArgs, OldParm->getLocation(),
2347 OldParm->getDeclName());
2348 }
2349
2350 if (!NewDI)
2351 return nullptr;
2352
2353 if (NewDI->getType()->isVoidType()) {
2354 Diag(OldParm->getLocation(), diag::err_param_with_void_type);
2355 return nullptr;
2356 }
2357
2358 // In abbreviated templates, TemplateTypeParmDecls with possible
2359 // TypeConstraints are created when the parameter list is originally parsed.
2360 // The TypeConstraints can therefore reference other functions parameters in
2361 // the abbreviated function template, which is why we must instantiate them
2362 // here, when the instantiated versions of those referenced parameters are in
2363 // scope.
2364 if (TemplateTypeParmDecl *TTP =
2365 GetContainedInventedTypeParmVisitor().Visit(OldDI->getType())) {
2366 if (const TypeConstraint *TC = TTP->getTypeConstraint()) {
2367 auto *Inst = cast_or_null<TemplateTypeParmDecl>(
2368 FindInstantiatedDecl(TTP->getLocation(), TTP, TemplateArgs));
2369 // We will first get here when instantiating the abbreviated function
2370 // template's described function, but we might also get here later.
2371 // Make sure we do not instantiate the TypeConstraint more than once.
2372 if (Inst && !Inst->getTypeConstraint()) {
2373 // TODO: Concepts: do not instantiate the constraint (delayed constraint
2374 // substitution)
2375 const ASTTemplateArgumentListInfo *TemplArgInfo
2376 = TC->getTemplateArgsAsWritten();
2377 TemplateArgumentListInfo InstArgs;
2378
2379 if (TemplArgInfo) {
2380 InstArgs.setLAngleLoc(TemplArgInfo->LAngleLoc);
2381 InstArgs.setRAngleLoc(TemplArgInfo->RAngleLoc);
2382 if (Subst(TemplArgInfo->getTemplateArgs(),
2383 TemplArgInfo->NumTemplateArgs, InstArgs, TemplateArgs))
2384 return nullptr;
2385 }
2386 if (AttachTypeConstraint(
2387 TC->getNestedNameSpecifierLoc(), TC->getConceptNameInfo(),
2388 TC->getNamedConcept(), &InstArgs, Inst,
2389 TTP->isParameterPack()
2390 ? cast<CXXFoldExpr>(TC->getImmediatelyDeclaredConstraint())
2391 ->getEllipsisLoc()
2392 : SourceLocation()))
2393 return nullptr;
2394 }
2395 }
2396 }
2397
2398 ParmVarDecl *NewParm = CheckParameter(Context.getTranslationUnitDecl(),
2399 OldParm->getInnerLocStart(),
2400 OldParm->getLocation(),
2401 OldParm->getIdentifier(),
2402 NewDI->getType(), NewDI,
2403 OldParm->getStorageClass());
2404 if (!NewParm)
2405 return nullptr;
2406
2407 // Mark the (new) default argument as uninstantiated (if any).
2408 if (OldParm->hasUninstantiatedDefaultArg()) {
2409 Expr *Arg = OldParm->getUninstantiatedDefaultArg();
2410 NewParm->setUninstantiatedDefaultArg(Arg);
2411 } else if (OldParm->hasUnparsedDefaultArg()) {
2412 NewParm->setUnparsedDefaultArg();
2413 UnparsedDefaultArgInstantiations[OldParm].push_back(NewParm);
2414 } else if (Expr *Arg = OldParm->getDefaultArg()) {
2415 FunctionDecl *OwningFunc = cast<FunctionDecl>(OldParm->getDeclContext());
2416 if (OwningFunc->isInLocalScopeForInstantiation()) {
2417 // Instantiate default arguments for methods of local classes (DR1484)
2418 // and non-defining declarations.
2419 Sema::ContextRAII SavedContext(*this, OwningFunc);
2420 LocalInstantiationScope Local(*this, true);
2421 ExprResult NewArg = SubstExpr(Arg, TemplateArgs);
2422 if (NewArg.isUsable()) {
2423 // It would be nice if we still had this.
2424 SourceLocation EqualLoc = NewArg.get()->getBeginLoc();
2425 ExprResult Result =
2426 ConvertParamDefaultArgument(NewParm, NewArg.get(), EqualLoc);
2427 if (Result.isInvalid())
2428 return nullptr;
2429
2430 SetParamDefaultArgument(NewParm, Result.getAs<Expr>(), EqualLoc);
2431 }
2432 } else {
2433 // FIXME: if we non-lazily instantiated non-dependent default args for
2434 // non-dependent parameter types we could remove a bunch of duplicate
2435 // conversion warnings for such arguments.
2436 NewParm->setUninstantiatedDefaultArg(Arg);
2437 }
2438 }
2439
2440 NewParm->setHasInheritedDefaultArg(OldParm->hasInheritedDefaultArg());
2441
2442 if (OldParm->isParameterPack() && !NewParm->isParameterPack()) {
2443 // Add the new parameter to the instantiated parameter pack.
2444 CurrentInstantiationScope->InstantiatedLocalPackArg(OldParm, NewParm);
2445 } else {
2446 // Introduce an Old -> New mapping
2447 CurrentInstantiationScope->InstantiatedLocal(OldParm, NewParm);
2448 }
2449
2450 // FIXME: OldParm may come from a FunctionProtoType, in which case CurContext
2451 // can be anything, is this right ?
2452 NewParm->setDeclContext(CurContext);
2453
2454 NewParm->setScopeInfo(OldParm->getFunctionScopeDepth(),
2455 OldParm->getFunctionScopeIndex() + indexAdjustment);
2456
2457 InstantiateAttrs(TemplateArgs, OldParm, NewParm);
2458
2459 return NewParm;
2460 }
2461
2462 /// Substitute the given template arguments into the given set of
2463 /// parameters, producing the set of parameter types that would be generated
2464 /// from such a substitution.
SubstParmTypes(SourceLocation Loc,ArrayRef<ParmVarDecl * > Params,const FunctionProtoType::ExtParameterInfo * ExtParamInfos,const MultiLevelTemplateArgumentList & TemplateArgs,SmallVectorImpl<QualType> & ParamTypes,SmallVectorImpl<ParmVarDecl * > * OutParams,ExtParameterInfoBuilder & ParamInfos)2465 bool Sema::SubstParmTypes(
2466 SourceLocation Loc, ArrayRef<ParmVarDecl *> Params,
2467 const FunctionProtoType::ExtParameterInfo *ExtParamInfos,
2468 const MultiLevelTemplateArgumentList &TemplateArgs,
2469 SmallVectorImpl<QualType> &ParamTypes,
2470 SmallVectorImpl<ParmVarDecl *> *OutParams,
2471 ExtParameterInfoBuilder &ParamInfos) {
2472 assert(!CodeSynthesisContexts.empty() &&
2473 "Cannot perform an instantiation without some context on the "
2474 "instantiation stack");
2475
2476 TemplateInstantiator Instantiator(*this, TemplateArgs, Loc,
2477 DeclarationName());
2478 return Instantiator.TransformFunctionTypeParams(
2479 Loc, Params, nullptr, ExtParamInfos, ParamTypes, OutParams, ParamInfos);
2480 }
2481
2482 /// Perform substitution on the base class specifiers of the
2483 /// given class template specialization.
2484 ///
2485 /// Produces a diagnostic and returns true on error, returns false and
2486 /// attaches the instantiated base classes to the class template
2487 /// specialization if successful.
2488 bool
SubstBaseSpecifiers(CXXRecordDecl * Instantiation,CXXRecordDecl * Pattern,const MultiLevelTemplateArgumentList & TemplateArgs)2489 Sema::SubstBaseSpecifiers(CXXRecordDecl *Instantiation,
2490 CXXRecordDecl *Pattern,
2491 const MultiLevelTemplateArgumentList &TemplateArgs) {
2492 bool Invalid = false;
2493 SmallVector<CXXBaseSpecifier*, 4> InstantiatedBases;
2494 for (const auto &Base : Pattern->bases()) {
2495 if (!Base.getType()->isDependentType()) {
2496 if (const CXXRecordDecl *RD = Base.getType()->getAsCXXRecordDecl()) {
2497 if (RD->isInvalidDecl())
2498 Instantiation->setInvalidDecl();
2499 }
2500 InstantiatedBases.push_back(new (Context) CXXBaseSpecifier(Base));
2501 continue;
2502 }
2503
2504 SourceLocation EllipsisLoc;
2505 TypeSourceInfo *BaseTypeLoc;
2506 if (Base.isPackExpansion()) {
2507 // This is a pack expansion. See whether we should expand it now, or
2508 // wait until later.
2509 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
2510 collectUnexpandedParameterPacks(Base.getTypeSourceInfo()->getTypeLoc(),
2511 Unexpanded);
2512 bool ShouldExpand = false;
2513 bool RetainExpansion = false;
2514 Optional<unsigned> NumExpansions;
2515 if (CheckParameterPacksForExpansion(Base.getEllipsisLoc(),
2516 Base.getSourceRange(),
2517 Unexpanded,
2518 TemplateArgs, ShouldExpand,
2519 RetainExpansion,
2520 NumExpansions)) {
2521 Invalid = true;
2522 continue;
2523 }
2524
2525 // If we should expand this pack expansion now, do so.
2526 if (ShouldExpand) {
2527 for (unsigned I = 0; I != *NumExpansions; ++I) {
2528 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, I);
2529
2530 TypeSourceInfo *BaseTypeLoc = SubstType(Base.getTypeSourceInfo(),
2531 TemplateArgs,
2532 Base.getSourceRange().getBegin(),
2533 DeclarationName());
2534 if (!BaseTypeLoc) {
2535 Invalid = true;
2536 continue;
2537 }
2538
2539 if (CXXBaseSpecifier *InstantiatedBase
2540 = CheckBaseSpecifier(Instantiation,
2541 Base.getSourceRange(),
2542 Base.isVirtual(),
2543 Base.getAccessSpecifierAsWritten(),
2544 BaseTypeLoc,
2545 SourceLocation()))
2546 InstantiatedBases.push_back(InstantiatedBase);
2547 else
2548 Invalid = true;
2549 }
2550
2551 continue;
2552 }
2553
2554 // The resulting base specifier will (still) be a pack expansion.
2555 EllipsisLoc = Base.getEllipsisLoc();
2556 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, -1);
2557 BaseTypeLoc = SubstType(Base.getTypeSourceInfo(),
2558 TemplateArgs,
2559 Base.getSourceRange().getBegin(),
2560 DeclarationName());
2561 } else {
2562 BaseTypeLoc = SubstType(Base.getTypeSourceInfo(),
2563 TemplateArgs,
2564 Base.getSourceRange().getBegin(),
2565 DeclarationName());
2566 }
2567
2568 if (!BaseTypeLoc) {
2569 Invalid = true;
2570 continue;
2571 }
2572
2573 if (CXXBaseSpecifier *InstantiatedBase
2574 = CheckBaseSpecifier(Instantiation,
2575 Base.getSourceRange(),
2576 Base.isVirtual(),
2577 Base.getAccessSpecifierAsWritten(),
2578 BaseTypeLoc,
2579 EllipsisLoc))
2580 InstantiatedBases.push_back(InstantiatedBase);
2581 else
2582 Invalid = true;
2583 }
2584
2585 if (!Invalid && AttachBaseSpecifiers(Instantiation, InstantiatedBases))
2586 Invalid = true;
2587
2588 return Invalid;
2589 }
2590
2591 // Defined via #include from SemaTemplateInstantiateDecl.cpp
2592 namespace clang {
2593 namespace sema {
2594 Attr *instantiateTemplateAttribute(const Attr *At, ASTContext &C, Sema &S,
2595 const MultiLevelTemplateArgumentList &TemplateArgs);
2596 Attr *instantiateTemplateAttributeForDecl(
2597 const Attr *At, ASTContext &C, Sema &S,
2598 const MultiLevelTemplateArgumentList &TemplateArgs);
2599 }
2600 }
2601
2602 /// Instantiate the definition of a class from a given pattern.
2603 ///
2604 /// \param PointOfInstantiation The point of instantiation within the
2605 /// source code.
2606 ///
2607 /// \param Instantiation is the declaration whose definition is being
2608 /// instantiated. This will be either a class template specialization
2609 /// or a member class of a class template specialization.
2610 ///
2611 /// \param Pattern is the pattern from which the instantiation
2612 /// occurs. This will be either the declaration of a class template or
2613 /// the declaration of a member class of a class template.
2614 ///
2615 /// \param TemplateArgs The template arguments to be substituted into
2616 /// the pattern.
2617 ///
2618 /// \param TSK the kind of implicit or explicit instantiation to perform.
2619 ///
2620 /// \param Complain whether to complain if the class cannot be instantiated due
2621 /// to the lack of a definition.
2622 ///
2623 /// \returns true if an error occurred, false otherwise.
2624 bool
InstantiateClass(SourceLocation PointOfInstantiation,CXXRecordDecl * Instantiation,CXXRecordDecl * Pattern,const MultiLevelTemplateArgumentList & TemplateArgs,TemplateSpecializationKind TSK,bool Complain)2625 Sema::InstantiateClass(SourceLocation PointOfInstantiation,
2626 CXXRecordDecl *Instantiation, CXXRecordDecl *Pattern,
2627 const MultiLevelTemplateArgumentList &TemplateArgs,
2628 TemplateSpecializationKind TSK,
2629 bool Complain) {
2630 CXXRecordDecl *PatternDef
2631 = cast_or_null<CXXRecordDecl>(Pattern->getDefinition());
2632 if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Instantiation,
2633 Instantiation->getInstantiatedFromMemberClass(),
2634 Pattern, PatternDef, TSK, Complain))
2635 return true;
2636
2637 llvm::TimeTraceScope TimeScope("InstantiateClass", [&]() {
2638 std::string Name;
2639 llvm::raw_string_ostream OS(Name);
2640 Instantiation->getNameForDiagnostic(OS, getPrintingPolicy(),
2641 /*Qualified=*/true);
2642 return Name;
2643 });
2644
2645 Pattern = PatternDef;
2646
2647 // Record the point of instantiation.
2648 if (MemberSpecializationInfo *MSInfo
2649 = Instantiation->getMemberSpecializationInfo()) {
2650 MSInfo->setTemplateSpecializationKind(TSK);
2651 MSInfo->setPointOfInstantiation(PointOfInstantiation);
2652 } else if (ClassTemplateSpecializationDecl *Spec
2653 = dyn_cast<ClassTemplateSpecializationDecl>(Instantiation)) {
2654 Spec->setTemplateSpecializationKind(TSK);
2655 Spec->setPointOfInstantiation(PointOfInstantiation);
2656 }
2657
2658 InstantiatingTemplate Inst(*this, PointOfInstantiation, Instantiation);
2659 if (Inst.isInvalid())
2660 return true;
2661 assert(!Inst.isAlreadyInstantiating() && "should have been caught by caller");
2662 PrettyDeclStackTraceEntry CrashInfo(Context, Instantiation, SourceLocation(),
2663 "instantiating class definition");
2664
2665 // Enter the scope of this instantiation. We don't use
2666 // PushDeclContext because we don't have a scope.
2667 ContextRAII SavedContext(*this, Instantiation);
2668 EnterExpressionEvaluationContext EvalContext(
2669 *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
2670
2671 // If this is an instantiation of a local class, merge this local
2672 // instantiation scope with the enclosing scope. Otherwise, every
2673 // instantiation of a class has its own local instantiation scope.
2674 bool MergeWithParentScope = !Instantiation->isDefinedOutsideFunctionOrMethod();
2675 LocalInstantiationScope Scope(*this, MergeWithParentScope);
2676
2677 // Some class state isn't processed immediately but delayed till class
2678 // instantiation completes. We may not be ready to handle any delayed state
2679 // already on the stack as it might correspond to a different class, so save
2680 // it now and put it back later.
2681 SavePendingParsedClassStateRAII SavedPendingParsedClassState(*this);
2682
2683 // Pull attributes from the pattern onto the instantiation.
2684 InstantiateAttrs(TemplateArgs, Pattern, Instantiation);
2685
2686 // Start the definition of this instantiation.
2687 Instantiation->startDefinition();
2688
2689 // The instantiation is visible here, even if it was first declared in an
2690 // unimported module.
2691 Instantiation->setVisibleDespiteOwningModule();
2692
2693 // FIXME: This loses the as-written tag kind for an explicit instantiation.
2694 Instantiation->setTagKind(Pattern->getTagKind());
2695
2696 // Do substitution on the base class specifiers.
2697 if (SubstBaseSpecifiers(Instantiation, Pattern, TemplateArgs))
2698 Instantiation->setInvalidDecl();
2699
2700 TemplateDeclInstantiator Instantiator(*this, Instantiation, TemplateArgs);
2701 SmallVector<Decl*, 4> Fields;
2702 // Delay instantiation of late parsed attributes.
2703 LateInstantiatedAttrVec LateAttrs;
2704 Instantiator.enableLateAttributeInstantiation(&LateAttrs);
2705
2706 bool MightHaveConstexprVirtualFunctions = false;
2707 for (auto *Member : Pattern->decls()) {
2708 // Don't instantiate members not belonging in this semantic context.
2709 // e.g. for:
2710 // @code
2711 // template <int i> class A {
2712 // class B *g;
2713 // };
2714 // @endcode
2715 // 'class B' has the template as lexical context but semantically it is
2716 // introduced in namespace scope.
2717 if (Member->getDeclContext() != Pattern)
2718 continue;
2719
2720 // BlockDecls can appear in a default-member-initializer. They must be the
2721 // child of a BlockExpr, so we only know how to instantiate them from there.
2722 // Similarly, lambda closure types are recreated when instantiating the
2723 // corresponding LambdaExpr.
2724 if (isa<BlockDecl>(Member) ||
2725 (isa<CXXRecordDecl>(Member) && cast<CXXRecordDecl>(Member)->isLambda()))
2726 continue;
2727
2728 if (Member->isInvalidDecl()) {
2729 Instantiation->setInvalidDecl();
2730 continue;
2731 }
2732
2733 Decl *NewMember = Instantiator.Visit(Member);
2734 if (NewMember) {
2735 if (FieldDecl *Field = dyn_cast<FieldDecl>(NewMember)) {
2736 Fields.push_back(Field);
2737 } else if (EnumDecl *Enum = dyn_cast<EnumDecl>(NewMember)) {
2738 // C++11 [temp.inst]p1: The implicit instantiation of a class template
2739 // specialization causes the implicit instantiation of the definitions
2740 // of unscoped member enumerations.
2741 // Record a point of instantiation for this implicit instantiation.
2742 if (TSK == TSK_ImplicitInstantiation && !Enum->isScoped() &&
2743 Enum->isCompleteDefinition()) {
2744 MemberSpecializationInfo *MSInfo =Enum->getMemberSpecializationInfo();
2745 assert(MSInfo && "no spec info for member enum specialization");
2746 MSInfo->setTemplateSpecializationKind(TSK_ImplicitInstantiation);
2747 MSInfo->setPointOfInstantiation(PointOfInstantiation);
2748 }
2749 } else if (StaticAssertDecl *SA = dyn_cast<StaticAssertDecl>(NewMember)) {
2750 if (SA->isFailed()) {
2751 // A static_assert failed. Bail out; instantiating this
2752 // class is probably not meaningful.
2753 Instantiation->setInvalidDecl();
2754 break;
2755 }
2756 } else if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewMember)) {
2757 if (MD->isConstexpr() && !MD->getFriendObjectKind() &&
2758 (MD->isVirtualAsWritten() || Instantiation->getNumBases()))
2759 MightHaveConstexprVirtualFunctions = true;
2760 }
2761
2762 if (NewMember->isInvalidDecl())
2763 Instantiation->setInvalidDecl();
2764 } else {
2765 // FIXME: Eventually, a NULL return will mean that one of the
2766 // instantiations was a semantic disaster, and we'll want to mark the
2767 // declaration invalid.
2768 // For now, we expect to skip some members that we can't yet handle.
2769 }
2770 }
2771
2772 // Finish checking fields.
2773 ActOnFields(nullptr, Instantiation->getLocation(), Instantiation, Fields,
2774 SourceLocation(), SourceLocation(), ParsedAttributesView());
2775 CheckCompletedCXXClass(nullptr, Instantiation);
2776
2777 // Default arguments are parsed, if not instantiated. We can go instantiate
2778 // default arg exprs for default constructors if necessary now. Unless we're
2779 // parsing a class, in which case wait until that's finished.
2780 if (ParsingClassDepth == 0)
2781 ActOnFinishCXXNonNestedClass();
2782
2783 // Instantiate late parsed attributes, and attach them to their decls.
2784 // See Sema::InstantiateAttrs
2785 for (LateInstantiatedAttrVec::iterator I = LateAttrs.begin(),
2786 E = LateAttrs.end(); I != E; ++I) {
2787 assert(CurrentInstantiationScope == Instantiator.getStartingScope());
2788 CurrentInstantiationScope = I->Scope;
2789
2790 // Allow 'this' within late-parsed attributes.
2791 NamedDecl *ND = dyn_cast<NamedDecl>(I->NewDecl);
2792 CXXRecordDecl *ThisContext =
2793 dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext());
2794 CXXThisScopeRAII ThisScope(*this, ThisContext, Qualifiers(),
2795 ND && ND->isCXXInstanceMember());
2796
2797 Attr *NewAttr =
2798 instantiateTemplateAttribute(I->TmplAttr, Context, *this, TemplateArgs);
2799 if (NewAttr)
2800 I->NewDecl->addAttr(NewAttr);
2801 LocalInstantiationScope::deleteScopes(I->Scope,
2802 Instantiator.getStartingScope());
2803 }
2804 Instantiator.disableLateAttributeInstantiation();
2805 LateAttrs.clear();
2806
2807 ActOnFinishDelayedMemberInitializers(Instantiation);
2808
2809 // FIXME: We should do something similar for explicit instantiations so they
2810 // end up in the right module.
2811 if (TSK == TSK_ImplicitInstantiation) {
2812 Instantiation->setLocation(Pattern->getLocation());
2813 Instantiation->setLocStart(Pattern->getInnerLocStart());
2814 Instantiation->setBraceRange(Pattern->getBraceRange());
2815 }
2816
2817 if (!Instantiation->isInvalidDecl()) {
2818 // Perform any dependent diagnostics from the pattern.
2819 PerformDependentDiagnostics(Pattern, TemplateArgs);
2820
2821 // Instantiate any out-of-line class template partial
2822 // specializations now.
2823 for (TemplateDeclInstantiator::delayed_partial_spec_iterator
2824 P = Instantiator.delayed_partial_spec_begin(),
2825 PEnd = Instantiator.delayed_partial_spec_end();
2826 P != PEnd; ++P) {
2827 if (!Instantiator.InstantiateClassTemplatePartialSpecialization(
2828 P->first, P->second)) {
2829 Instantiation->setInvalidDecl();
2830 break;
2831 }
2832 }
2833
2834 // Instantiate any out-of-line variable template partial
2835 // specializations now.
2836 for (TemplateDeclInstantiator::delayed_var_partial_spec_iterator
2837 P = Instantiator.delayed_var_partial_spec_begin(),
2838 PEnd = Instantiator.delayed_var_partial_spec_end();
2839 P != PEnd; ++P) {
2840 if (!Instantiator.InstantiateVarTemplatePartialSpecialization(
2841 P->first, P->second)) {
2842 Instantiation->setInvalidDecl();
2843 break;
2844 }
2845 }
2846 }
2847
2848 // Exit the scope of this instantiation.
2849 SavedContext.pop();
2850
2851 if (!Instantiation->isInvalidDecl()) {
2852 // Always emit the vtable for an explicit instantiation definition
2853 // of a polymorphic class template specialization. Otherwise, eagerly
2854 // instantiate only constexpr virtual functions in preparation for their use
2855 // in constant evaluation.
2856 if (TSK == TSK_ExplicitInstantiationDefinition)
2857 MarkVTableUsed(PointOfInstantiation, Instantiation, true);
2858 else if (MightHaveConstexprVirtualFunctions)
2859 MarkVirtualMembersReferenced(PointOfInstantiation, Instantiation,
2860 /*ConstexprOnly*/ true);
2861 }
2862
2863 Consumer.HandleTagDeclDefinition(Instantiation);
2864
2865 return Instantiation->isInvalidDecl();
2866 }
2867
2868 /// Instantiate the definition of an enum from a given pattern.
2869 ///
2870 /// \param PointOfInstantiation The point of instantiation within the
2871 /// source code.
2872 /// \param Instantiation is the declaration whose definition is being
2873 /// instantiated. This will be a member enumeration of a class
2874 /// temploid specialization, or a local enumeration within a
2875 /// function temploid specialization.
2876 /// \param Pattern The templated declaration from which the instantiation
2877 /// occurs.
2878 /// \param TemplateArgs The template arguments to be substituted into
2879 /// the pattern.
2880 /// \param TSK The kind of implicit or explicit instantiation to perform.
2881 ///
2882 /// \return \c true if an error occurred, \c false otherwise.
InstantiateEnum(SourceLocation PointOfInstantiation,EnumDecl * Instantiation,EnumDecl * Pattern,const MultiLevelTemplateArgumentList & TemplateArgs,TemplateSpecializationKind TSK)2883 bool Sema::InstantiateEnum(SourceLocation PointOfInstantiation,
2884 EnumDecl *Instantiation, EnumDecl *Pattern,
2885 const MultiLevelTemplateArgumentList &TemplateArgs,
2886 TemplateSpecializationKind TSK) {
2887 EnumDecl *PatternDef = Pattern->getDefinition();
2888 if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Instantiation,
2889 Instantiation->getInstantiatedFromMemberEnum(),
2890 Pattern, PatternDef, TSK,/*Complain*/true))
2891 return true;
2892 Pattern = PatternDef;
2893
2894 // Record the point of instantiation.
2895 if (MemberSpecializationInfo *MSInfo
2896 = Instantiation->getMemberSpecializationInfo()) {
2897 MSInfo->setTemplateSpecializationKind(TSK);
2898 MSInfo->setPointOfInstantiation(PointOfInstantiation);
2899 }
2900
2901 InstantiatingTemplate Inst(*this, PointOfInstantiation, Instantiation);
2902 if (Inst.isInvalid())
2903 return true;
2904 if (Inst.isAlreadyInstantiating())
2905 return false;
2906 PrettyDeclStackTraceEntry CrashInfo(Context, Instantiation, SourceLocation(),
2907 "instantiating enum definition");
2908
2909 // The instantiation is visible here, even if it was first declared in an
2910 // unimported module.
2911 Instantiation->setVisibleDespiteOwningModule();
2912
2913 // Enter the scope of this instantiation. We don't use
2914 // PushDeclContext because we don't have a scope.
2915 ContextRAII SavedContext(*this, Instantiation);
2916 EnterExpressionEvaluationContext EvalContext(
2917 *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
2918
2919 LocalInstantiationScope Scope(*this, /*MergeWithParentScope*/true);
2920
2921 // Pull attributes from the pattern onto the instantiation.
2922 InstantiateAttrs(TemplateArgs, Pattern, Instantiation);
2923
2924 TemplateDeclInstantiator Instantiator(*this, Instantiation, TemplateArgs);
2925 Instantiator.InstantiateEnumDefinition(Instantiation, Pattern);
2926
2927 // Exit the scope of this instantiation.
2928 SavedContext.pop();
2929
2930 return Instantiation->isInvalidDecl();
2931 }
2932
2933
2934 /// Instantiate the definition of a field from the given pattern.
2935 ///
2936 /// \param PointOfInstantiation The point of instantiation within the
2937 /// source code.
2938 /// \param Instantiation is the declaration whose definition is being
2939 /// instantiated. This will be a class of a class temploid
2940 /// specialization, or a local enumeration within a function temploid
2941 /// specialization.
2942 /// \param Pattern The templated declaration from which the instantiation
2943 /// occurs.
2944 /// \param TemplateArgs The template arguments to be substituted into
2945 /// the pattern.
2946 ///
2947 /// \return \c true if an error occurred, \c false otherwise.
InstantiateInClassInitializer(SourceLocation PointOfInstantiation,FieldDecl * Instantiation,FieldDecl * Pattern,const MultiLevelTemplateArgumentList & TemplateArgs)2948 bool Sema::InstantiateInClassInitializer(
2949 SourceLocation PointOfInstantiation, FieldDecl *Instantiation,
2950 FieldDecl *Pattern, const MultiLevelTemplateArgumentList &TemplateArgs) {
2951 // If there is no initializer, we don't need to do anything.
2952 if (!Pattern->hasInClassInitializer())
2953 return false;
2954
2955 assert(Instantiation->getInClassInitStyle() ==
2956 Pattern->getInClassInitStyle() &&
2957 "pattern and instantiation disagree about init style");
2958
2959 // Error out if we haven't parsed the initializer of the pattern yet because
2960 // we are waiting for the closing brace of the outer class.
2961 Expr *OldInit = Pattern->getInClassInitializer();
2962 if (!OldInit) {
2963 RecordDecl *PatternRD = Pattern->getParent();
2964 RecordDecl *OutermostClass = PatternRD->getOuterLexicalRecordContext();
2965 Diag(PointOfInstantiation,
2966 diag::err_default_member_initializer_not_yet_parsed)
2967 << OutermostClass << Pattern;
2968 Diag(Pattern->getEndLoc(),
2969 diag::note_default_member_initializer_not_yet_parsed);
2970 Instantiation->setInvalidDecl();
2971 return true;
2972 }
2973
2974 InstantiatingTemplate Inst(*this, PointOfInstantiation, Instantiation);
2975 if (Inst.isInvalid())
2976 return true;
2977 if (Inst.isAlreadyInstantiating()) {
2978 // Error out if we hit an instantiation cycle for this initializer.
2979 Diag(PointOfInstantiation, diag::err_default_member_initializer_cycle)
2980 << Instantiation;
2981 return true;
2982 }
2983 PrettyDeclStackTraceEntry CrashInfo(Context, Instantiation, SourceLocation(),
2984 "instantiating default member init");
2985
2986 // Enter the scope of this instantiation. We don't use PushDeclContext because
2987 // we don't have a scope.
2988 ContextRAII SavedContext(*this, Instantiation->getParent());
2989 EnterExpressionEvaluationContext EvalContext(
2990 *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
2991
2992 LocalInstantiationScope Scope(*this, true);
2993
2994 // Instantiate the initializer.
2995 ActOnStartCXXInClassMemberInitializer();
2996 CXXThisScopeRAII ThisScope(*this, Instantiation->getParent(), Qualifiers());
2997
2998 ExprResult NewInit = SubstInitializer(OldInit, TemplateArgs,
2999 /*CXXDirectInit=*/false);
3000 Expr *Init = NewInit.get();
3001 assert((!Init || !isa<ParenListExpr>(Init)) && "call-style init in class");
3002 ActOnFinishCXXInClassMemberInitializer(
3003 Instantiation, Init ? Init->getBeginLoc() : SourceLocation(), Init);
3004
3005 if (auto *L = getASTMutationListener())
3006 L->DefaultMemberInitializerInstantiated(Instantiation);
3007
3008 // Return true if the in-class initializer is still missing.
3009 return !Instantiation->getInClassInitializer();
3010 }
3011
3012 namespace {
3013 /// A partial specialization whose template arguments have matched
3014 /// a given template-id.
3015 struct PartialSpecMatchResult {
3016 ClassTemplatePartialSpecializationDecl *Partial;
3017 TemplateArgumentList *Args;
3018 };
3019 }
3020
usesPartialOrExplicitSpecialization(SourceLocation Loc,ClassTemplateSpecializationDecl * ClassTemplateSpec)3021 bool Sema::usesPartialOrExplicitSpecialization(
3022 SourceLocation Loc, ClassTemplateSpecializationDecl *ClassTemplateSpec) {
3023 if (ClassTemplateSpec->getTemplateSpecializationKind() ==
3024 TSK_ExplicitSpecialization)
3025 return true;
3026
3027 SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
3028 ClassTemplateSpec->getSpecializedTemplate()
3029 ->getPartialSpecializations(PartialSpecs);
3030 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) {
3031 TemplateDeductionInfo Info(Loc);
3032 if (!DeduceTemplateArguments(PartialSpecs[I],
3033 ClassTemplateSpec->getTemplateArgs(), Info))
3034 return true;
3035 }
3036
3037 return false;
3038 }
3039
3040 /// Get the instantiation pattern to use to instantiate the definition of a
3041 /// given ClassTemplateSpecializationDecl (either the pattern of the primary
3042 /// template or of a partial specialization).
3043 static ActionResult<CXXRecordDecl *>
getPatternForClassTemplateSpecialization(Sema & S,SourceLocation PointOfInstantiation,ClassTemplateSpecializationDecl * ClassTemplateSpec,TemplateSpecializationKind TSK)3044 getPatternForClassTemplateSpecialization(
3045 Sema &S, SourceLocation PointOfInstantiation,
3046 ClassTemplateSpecializationDecl *ClassTemplateSpec,
3047 TemplateSpecializationKind TSK) {
3048 Sema::InstantiatingTemplate Inst(S, PointOfInstantiation, ClassTemplateSpec);
3049 if (Inst.isInvalid())
3050 return {/*Invalid=*/true};
3051 if (Inst.isAlreadyInstantiating())
3052 return {/*Invalid=*/false};
3053
3054 llvm::PointerUnion<ClassTemplateDecl *,
3055 ClassTemplatePartialSpecializationDecl *>
3056 Specialized = ClassTemplateSpec->getSpecializedTemplateOrPartial();
3057 if (!Specialized.is<ClassTemplatePartialSpecializationDecl *>()) {
3058 // Find best matching specialization.
3059 ClassTemplateDecl *Template = ClassTemplateSpec->getSpecializedTemplate();
3060
3061 // C++ [temp.class.spec.match]p1:
3062 // When a class template is used in a context that requires an
3063 // instantiation of the class, it is necessary to determine
3064 // whether the instantiation is to be generated using the primary
3065 // template or one of the partial specializations. This is done by
3066 // matching the template arguments of the class template
3067 // specialization with the template argument lists of the partial
3068 // specializations.
3069 typedef PartialSpecMatchResult MatchResult;
3070 SmallVector<MatchResult, 4> Matched;
3071 SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs;
3072 Template->getPartialSpecializations(PartialSpecs);
3073 TemplateSpecCandidateSet FailedCandidates(PointOfInstantiation);
3074 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) {
3075 ClassTemplatePartialSpecializationDecl *Partial = PartialSpecs[I];
3076 TemplateDeductionInfo Info(FailedCandidates.getLocation());
3077 if (Sema::TemplateDeductionResult Result = S.DeduceTemplateArguments(
3078 Partial, ClassTemplateSpec->getTemplateArgs(), Info)) {
3079 // Store the failed-deduction information for use in diagnostics, later.
3080 // TODO: Actually use the failed-deduction info?
3081 FailedCandidates.addCandidate().set(
3082 DeclAccessPair::make(Template, AS_public), Partial,
3083 MakeDeductionFailureInfo(S.Context, Result, Info));
3084 (void)Result;
3085 } else {
3086 Matched.push_back(PartialSpecMatchResult());
3087 Matched.back().Partial = Partial;
3088 Matched.back().Args = Info.take();
3089 }
3090 }
3091
3092 // If we're dealing with a member template where the template parameters
3093 // have been instantiated, this provides the original template parameters
3094 // from which the member template's parameters were instantiated.
3095
3096 if (Matched.size() >= 1) {
3097 SmallVectorImpl<MatchResult>::iterator Best = Matched.begin();
3098 if (Matched.size() == 1) {
3099 // -- If exactly one matching specialization is found, the
3100 // instantiation is generated from that specialization.
3101 // We don't need to do anything for this.
3102 } else {
3103 // -- If more than one matching specialization is found, the
3104 // partial order rules (14.5.4.2) are used to determine
3105 // whether one of the specializations is more specialized
3106 // than the others. If none of the specializations is more
3107 // specialized than all of the other matching
3108 // specializations, then the use of the class template is
3109 // ambiguous and the program is ill-formed.
3110 for (SmallVectorImpl<MatchResult>::iterator P = Best + 1,
3111 PEnd = Matched.end();
3112 P != PEnd; ++P) {
3113 if (S.getMoreSpecializedPartialSpecialization(
3114 P->Partial, Best->Partial, PointOfInstantiation) ==
3115 P->Partial)
3116 Best = P;
3117 }
3118
3119 // Determine if the best partial specialization is more specialized than
3120 // the others.
3121 bool Ambiguous = false;
3122 for (SmallVectorImpl<MatchResult>::iterator P = Matched.begin(),
3123 PEnd = Matched.end();
3124 P != PEnd; ++P) {
3125 if (P != Best && S.getMoreSpecializedPartialSpecialization(
3126 P->Partial, Best->Partial,
3127 PointOfInstantiation) != Best->Partial) {
3128 Ambiguous = true;
3129 break;
3130 }
3131 }
3132
3133 if (Ambiguous) {
3134 // Partial ordering did not produce a clear winner. Complain.
3135 Inst.Clear();
3136 ClassTemplateSpec->setInvalidDecl();
3137 S.Diag(PointOfInstantiation,
3138 diag::err_partial_spec_ordering_ambiguous)
3139 << ClassTemplateSpec;
3140
3141 // Print the matching partial specializations.
3142 for (SmallVectorImpl<MatchResult>::iterator P = Matched.begin(),
3143 PEnd = Matched.end();
3144 P != PEnd; ++P)
3145 S.Diag(P->Partial->getLocation(), diag::note_partial_spec_match)
3146 << S.getTemplateArgumentBindingsText(
3147 P->Partial->getTemplateParameters(), *P->Args);
3148
3149 return {/*Invalid=*/true};
3150 }
3151 }
3152
3153 ClassTemplateSpec->setInstantiationOf(Best->Partial, Best->Args);
3154 } else {
3155 // -- If no matches are found, the instantiation is generated
3156 // from the primary template.
3157 }
3158 }
3159
3160 CXXRecordDecl *Pattern = nullptr;
3161 Specialized = ClassTemplateSpec->getSpecializedTemplateOrPartial();
3162 if (auto *PartialSpec =
3163 Specialized.dyn_cast<ClassTemplatePartialSpecializationDecl *>()) {
3164 // Instantiate using the best class template partial specialization.
3165 while (PartialSpec->getInstantiatedFromMember()) {
3166 // If we've found an explicit specialization of this class template,
3167 // stop here and use that as the pattern.
3168 if (PartialSpec->isMemberSpecialization())
3169 break;
3170
3171 PartialSpec = PartialSpec->getInstantiatedFromMember();
3172 }
3173 Pattern = PartialSpec;
3174 } else {
3175 ClassTemplateDecl *Template = ClassTemplateSpec->getSpecializedTemplate();
3176 while (Template->getInstantiatedFromMemberTemplate()) {
3177 // If we've found an explicit specialization of this class template,
3178 // stop here and use that as the pattern.
3179 if (Template->isMemberSpecialization())
3180 break;
3181
3182 Template = Template->getInstantiatedFromMemberTemplate();
3183 }
3184 Pattern = Template->getTemplatedDecl();
3185 }
3186
3187 return Pattern;
3188 }
3189
InstantiateClassTemplateSpecialization(SourceLocation PointOfInstantiation,ClassTemplateSpecializationDecl * ClassTemplateSpec,TemplateSpecializationKind TSK,bool Complain)3190 bool Sema::InstantiateClassTemplateSpecialization(
3191 SourceLocation PointOfInstantiation,
3192 ClassTemplateSpecializationDecl *ClassTemplateSpec,
3193 TemplateSpecializationKind TSK, bool Complain) {
3194 // Perform the actual instantiation on the canonical declaration.
3195 ClassTemplateSpec = cast<ClassTemplateSpecializationDecl>(
3196 ClassTemplateSpec->getCanonicalDecl());
3197 if (ClassTemplateSpec->isInvalidDecl())
3198 return true;
3199
3200 ActionResult<CXXRecordDecl *> Pattern =
3201 getPatternForClassTemplateSpecialization(*this, PointOfInstantiation,
3202 ClassTemplateSpec, TSK);
3203 if (!Pattern.isUsable())
3204 return Pattern.isInvalid();
3205
3206 return InstantiateClass(
3207 PointOfInstantiation, ClassTemplateSpec, Pattern.get(),
3208 getTemplateInstantiationArgs(ClassTemplateSpec), TSK, Complain);
3209 }
3210
3211 /// Instantiates the definitions of all of the member
3212 /// of the given class, which is an instantiation of a class template
3213 /// or a member class of a template.
3214 void
InstantiateClassMembers(SourceLocation PointOfInstantiation,CXXRecordDecl * Instantiation,const MultiLevelTemplateArgumentList & TemplateArgs,TemplateSpecializationKind TSK)3215 Sema::InstantiateClassMembers(SourceLocation PointOfInstantiation,
3216 CXXRecordDecl *Instantiation,
3217 const MultiLevelTemplateArgumentList &TemplateArgs,
3218 TemplateSpecializationKind TSK) {
3219 // FIXME: We need to notify the ASTMutationListener that we did all of these
3220 // things, in case we have an explicit instantiation definition in a PCM, a
3221 // module, or preamble, and the declaration is in an imported AST.
3222 assert(
3223 (TSK == TSK_ExplicitInstantiationDefinition ||
3224 TSK == TSK_ExplicitInstantiationDeclaration ||
3225 (TSK == TSK_ImplicitInstantiation && Instantiation->isLocalClass())) &&
3226 "Unexpected template specialization kind!");
3227 for (auto *D : Instantiation->decls()) {
3228 bool SuppressNew = false;
3229 if (auto *Function = dyn_cast<FunctionDecl>(D)) {
3230 if (FunctionDecl *Pattern =
3231 Function->getInstantiatedFromMemberFunction()) {
3232
3233 if (Function->hasAttr<ExcludeFromExplicitInstantiationAttr>())
3234 continue;
3235
3236 MemberSpecializationInfo *MSInfo =
3237 Function->getMemberSpecializationInfo();
3238 assert(MSInfo && "No member specialization information?");
3239 if (MSInfo->getTemplateSpecializationKind()
3240 == TSK_ExplicitSpecialization)
3241 continue;
3242
3243 if (CheckSpecializationInstantiationRedecl(PointOfInstantiation, TSK,
3244 Function,
3245 MSInfo->getTemplateSpecializationKind(),
3246 MSInfo->getPointOfInstantiation(),
3247 SuppressNew) ||
3248 SuppressNew)
3249 continue;
3250
3251 // C++11 [temp.explicit]p8:
3252 // An explicit instantiation definition that names a class template
3253 // specialization explicitly instantiates the class template
3254 // specialization and is only an explicit instantiation definition
3255 // of members whose definition is visible at the point of
3256 // instantiation.
3257 if (TSK == TSK_ExplicitInstantiationDefinition && !Pattern->isDefined())
3258 continue;
3259
3260 Function->setTemplateSpecializationKind(TSK, PointOfInstantiation);
3261
3262 if (Function->isDefined()) {
3263 // Let the ASTConsumer know that this function has been explicitly
3264 // instantiated now, and its linkage might have changed.
3265 Consumer.HandleTopLevelDecl(DeclGroupRef(Function));
3266 } else if (TSK == TSK_ExplicitInstantiationDefinition) {
3267 InstantiateFunctionDefinition(PointOfInstantiation, Function);
3268 } else if (TSK == TSK_ImplicitInstantiation) {
3269 PendingLocalImplicitInstantiations.push_back(
3270 std::make_pair(Function, PointOfInstantiation));
3271 }
3272 }
3273 } else if (auto *Var = dyn_cast<VarDecl>(D)) {
3274 if (isa<VarTemplateSpecializationDecl>(Var))
3275 continue;
3276
3277 if (Var->isStaticDataMember()) {
3278 if (Var->hasAttr<ExcludeFromExplicitInstantiationAttr>())
3279 continue;
3280
3281 MemberSpecializationInfo *MSInfo = Var->getMemberSpecializationInfo();
3282 assert(MSInfo && "No member specialization information?");
3283 if (MSInfo->getTemplateSpecializationKind()
3284 == TSK_ExplicitSpecialization)
3285 continue;
3286
3287 if (CheckSpecializationInstantiationRedecl(PointOfInstantiation, TSK,
3288 Var,
3289 MSInfo->getTemplateSpecializationKind(),
3290 MSInfo->getPointOfInstantiation(),
3291 SuppressNew) ||
3292 SuppressNew)
3293 continue;
3294
3295 if (TSK == TSK_ExplicitInstantiationDefinition) {
3296 // C++0x [temp.explicit]p8:
3297 // An explicit instantiation definition that names a class template
3298 // specialization explicitly instantiates the class template
3299 // specialization and is only an explicit instantiation definition
3300 // of members whose definition is visible at the point of
3301 // instantiation.
3302 if (!Var->getInstantiatedFromStaticDataMember()->getDefinition())
3303 continue;
3304
3305 Var->setTemplateSpecializationKind(TSK, PointOfInstantiation);
3306 InstantiateVariableDefinition(PointOfInstantiation, Var);
3307 } else {
3308 Var->setTemplateSpecializationKind(TSK, PointOfInstantiation);
3309 }
3310 }
3311 } else if (auto *Record = dyn_cast<CXXRecordDecl>(D)) {
3312 if (Record->hasAttr<ExcludeFromExplicitInstantiationAttr>())
3313 continue;
3314
3315 // Always skip the injected-class-name, along with any
3316 // redeclarations of nested classes, since both would cause us
3317 // to try to instantiate the members of a class twice.
3318 // Skip closure types; they'll get instantiated when we instantiate
3319 // the corresponding lambda-expression.
3320 if (Record->isInjectedClassName() || Record->getPreviousDecl() ||
3321 Record->isLambda())
3322 continue;
3323
3324 MemberSpecializationInfo *MSInfo = Record->getMemberSpecializationInfo();
3325 assert(MSInfo && "No member specialization information?");
3326
3327 if (MSInfo->getTemplateSpecializationKind()
3328 == TSK_ExplicitSpecialization)
3329 continue;
3330
3331 if (Context.getTargetInfo().getTriple().isOSWindows() &&
3332 TSK == TSK_ExplicitInstantiationDeclaration) {
3333 // On Windows, explicit instantiation decl of the outer class doesn't
3334 // affect the inner class. Typically extern template declarations are
3335 // used in combination with dll import/export annotations, but those
3336 // are not propagated from the outer class templates to inner classes.
3337 // Therefore, do not instantiate inner classes on this platform, so
3338 // that users don't end up with undefined symbols during linking.
3339 continue;
3340 }
3341
3342 if (CheckSpecializationInstantiationRedecl(PointOfInstantiation, TSK,
3343 Record,
3344 MSInfo->getTemplateSpecializationKind(),
3345 MSInfo->getPointOfInstantiation(),
3346 SuppressNew) ||
3347 SuppressNew)
3348 continue;
3349
3350 CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass();
3351 assert(Pattern && "Missing instantiated-from-template information");
3352
3353 if (!Record->getDefinition()) {
3354 if (!Pattern->getDefinition()) {
3355 // C++0x [temp.explicit]p8:
3356 // An explicit instantiation definition that names a class template
3357 // specialization explicitly instantiates the class template
3358 // specialization and is only an explicit instantiation definition
3359 // of members whose definition is visible at the point of
3360 // instantiation.
3361 if (TSK == TSK_ExplicitInstantiationDeclaration) {
3362 MSInfo->setTemplateSpecializationKind(TSK);
3363 MSInfo->setPointOfInstantiation(PointOfInstantiation);
3364 }
3365
3366 continue;
3367 }
3368
3369 InstantiateClass(PointOfInstantiation, Record, Pattern,
3370 TemplateArgs,
3371 TSK);
3372 } else {
3373 if (TSK == TSK_ExplicitInstantiationDefinition &&
3374 Record->getTemplateSpecializationKind() ==
3375 TSK_ExplicitInstantiationDeclaration) {
3376 Record->setTemplateSpecializationKind(TSK);
3377 MarkVTableUsed(PointOfInstantiation, Record, true);
3378 }
3379 }
3380
3381 Pattern = cast_or_null<CXXRecordDecl>(Record->getDefinition());
3382 if (Pattern)
3383 InstantiateClassMembers(PointOfInstantiation, Pattern, TemplateArgs,
3384 TSK);
3385 } else if (auto *Enum = dyn_cast<EnumDecl>(D)) {
3386 MemberSpecializationInfo *MSInfo = Enum->getMemberSpecializationInfo();
3387 assert(MSInfo && "No member specialization information?");
3388
3389 if (MSInfo->getTemplateSpecializationKind()
3390 == TSK_ExplicitSpecialization)
3391 continue;
3392
3393 if (CheckSpecializationInstantiationRedecl(
3394 PointOfInstantiation, TSK, Enum,
3395 MSInfo->getTemplateSpecializationKind(),
3396 MSInfo->getPointOfInstantiation(), SuppressNew) ||
3397 SuppressNew)
3398 continue;
3399
3400 if (Enum->getDefinition())
3401 continue;
3402
3403 EnumDecl *Pattern = Enum->getTemplateInstantiationPattern();
3404 assert(Pattern && "Missing instantiated-from-template information");
3405
3406 if (TSK == TSK_ExplicitInstantiationDefinition) {
3407 if (!Pattern->getDefinition())
3408 continue;
3409
3410 InstantiateEnum(PointOfInstantiation, Enum, Pattern, TemplateArgs, TSK);
3411 } else {
3412 MSInfo->setTemplateSpecializationKind(TSK);
3413 MSInfo->setPointOfInstantiation(PointOfInstantiation);
3414 }
3415 } else if (auto *Field = dyn_cast<FieldDecl>(D)) {
3416 // No need to instantiate in-class initializers during explicit
3417 // instantiation.
3418 if (Field->hasInClassInitializer() && TSK == TSK_ImplicitInstantiation) {
3419 CXXRecordDecl *ClassPattern =
3420 Instantiation->getTemplateInstantiationPattern();
3421 DeclContext::lookup_result Lookup =
3422 ClassPattern->lookup(Field->getDeclName());
3423 FieldDecl *Pattern = cast<FieldDecl>(Lookup.front());
3424 InstantiateInClassInitializer(PointOfInstantiation, Field, Pattern,
3425 TemplateArgs);
3426 }
3427 }
3428 }
3429 }
3430
3431 /// Instantiate the definitions of all of the members of the
3432 /// given class template specialization, which was named as part of an
3433 /// explicit instantiation.
3434 void
InstantiateClassTemplateSpecializationMembers(SourceLocation PointOfInstantiation,ClassTemplateSpecializationDecl * ClassTemplateSpec,TemplateSpecializationKind TSK)3435 Sema::InstantiateClassTemplateSpecializationMembers(
3436 SourceLocation PointOfInstantiation,
3437 ClassTemplateSpecializationDecl *ClassTemplateSpec,
3438 TemplateSpecializationKind TSK) {
3439 // C++0x [temp.explicit]p7:
3440 // An explicit instantiation that names a class template
3441 // specialization is an explicit instantion of the same kind
3442 // (declaration or definition) of each of its members (not
3443 // including members inherited from base classes) that has not
3444 // been previously explicitly specialized in the translation unit
3445 // containing the explicit instantiation, except as described
3446 // below.
3447 InstantiateClassMembers(PointOfInstantiation, ClassTemplateSpec,
3448 getTemplateInstantiationArgs(ClassTemplateSpec),
3449 TSK);
3450 }
3451
3452 StmtResult
SubstStmt(Stmt * S,const MultiLevelTemplateArgumentList & TemplateArgs)3453 Sema::SubstStmt(Stmt *S, const MultiLevelTemplateArgumentList &TemplateArgs) {
3454 if (!S)
3455 return S;
3456
3457 TemplateInstantiator Instantiator(*this, TemplateArgs,
3458 SourceLocation(),
3459 DeclarationName());
3460 return Instantiator.TransformStmt(S);
3461 }
3462
SubstTemplateArguments(ArrayRef<TemplateArgumentLoc> Args,const MultiLevelTemplateArgumentList & TemplateArgs,TemplateArgumentListInfo & Out)3463 bool Sema::SubstTemplateArguments(
3464 ArrayRef<TemplateArgumentLoc> Args,
3465 const MultiLevelTemplateArgumentList &TemplateArgs,
3466 TemplateArgumentListInfo &Out) {
3467 TemplateInstantiator Instantiator(*this, TemplateArgs,
3468 SourceLocation(),
3469 DeclarationName());
3470 return Instantiator.TransformTemplateArguments(Args.begin(), Args.end(),
3471 Out);
3472 }
3473
3474 ExprResult
SubstExpr(Expr * E,const MultiLevelTemplateArgumentList & TemplateArgs)3475 Sema::SubstExpr(Expr *E, const MultiLevelTemplateArgumentList &TemplateArgs) {
3476 if (!E)
3477 return E;
3478
3479 TemplateInstantiator Instantiator(*this, TemplateArgs,
3480 SourceLocation(),
3481 DeclarationName());
3482 return Instantiator.TransformExpr(E);
3483 }
3484
SubstInitializer(Expr * Init,const MultiLevelTemplateArgumentList & TemplateArgs,bool CXXDirectInit)3485 ExprResult Sema::SubstInitializer(Expr *Init,
3486 const MultiLevelTemplateArgumentList &TemplateArgs,
3487 bool CXXDirectInit) {
3488 TemplateInstantiator Instantiator(*this, TemplateArgs,
3489 SourceLocation(),
3490 DeclarationName());
3491 return Instantiator.TransformInitializer(Init, CXXDirectInit);
3492 }
3493
SubstExprs(ArrayRef<Expr * > Exprs,bool IsCall,const MultiLevelTemplateArgumentList & TemplateArgs,SmallVectorImpl<Expr * > & Outputs)3494 bool Sema::SubstExprs(ArrayRef<Expr *> Exprs, bool IsCall,
3495 const MultiLevelTemplateArgumentList &TemplateArgs,
3496 SmallVectorImpl<Expr *> &Outputs) {
3497 if (Exprs.empty())
3498 return false;
3499
3500 TemplateInstantiator Instantiator(*this, TemplateArgs,
3501 SourceLocation(),
3502 DeclarationName());
3503 return Instantiator.TransformExprs(Exprs.data(), Exprs.size(),
3504 IsCall, Outputs);
3505 }
3506
3507 NestedNameSpecifierLoc
SubstNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS,const MultiLevelTemplateArgumentList & TemplateArgs)3508 Sema::SubstNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS,
3509 const MultiLevelTemplateArgumentList &TemplateArgs) {
3510 if (!NNS)
3511 return NestedNameSpecifierLoc();
3512
3513 TemplateInstantiator Instantiator(*this, TemplateArgs, NNS.getBeginLoc(),
3514 DeclarationName());
3515 return Instantiator.TransformNestedNameSpecifierLoc(NNS);
3516 }
3517
3518 /// Do template substitution on declaration name info.
3519 DeclarationNameInfo
SubstDeclarationNameInfo(const DeclarationNameInfo & NameInfo,const MultiLevelTemplateArgumentList & TemplateArgs)3520 Sema::SubstDeclarationNameInfo(const DeclarationNameInfo &NameInfo,
3521 const MultiLevelTemplateArgumentList &TemplateArgs) {
3522 TemplateInstantiator Instantiator(*this, TemplateArgs, NameInfo.getLoc(),
3523 NameInfo.getName());
3524 return Instantiator.TransformDeclarationNameInfo(NameInfo);
3525 }
3526
3527 TemplateName
SubstTemplateName(NestedNameSpecifierLoc QualifierLoc,TemplateName Name,SourceLocation Loc,const MultiLevelTemplateArgumentList & TemplateArgs)3528 Sema::SubstTemplateName(NestedNameSpecifierLoc QualifierLoc,
3529 TemplateName Name, SourceLocation Loc,
3530 const MultiLevelTemplateArgumentList &TemplateArgs) {
3531 TemplateInstantiator Instantiator(*this, TemplateArgs, Loc,
3532 DeclarationName());
3533 CXXScopeSpec SS;
3534 SS.Adopt(QualifierLoc);
3535 return Instantiator.TransformTemplateName(SS, Name, Loc);
3536 }
3537
Subst(const TemplateArgumentLoc * Args,unsigned NumArgs,TemplateArgumentListInfo & Result,const MultiLevelTemplateArgumentList & TemplateArgs)3538 bool Sema::Subst(const TemplateArgumentLoc *Args, unsigned NumArgs,
3539 TemplateArgumentListInfo &Result,
3540 const MultiLevelTemplateArgumentList &TemplateArgs) {
3541 TemplateInstantiator Instantiator(*this, TemplateArgs, SourceLocation(),
3542 DeclarationName());
3543
3544 return Instantiator.TransformTemplateArguments(Args, NumArgs, Result);
3545 }
3546
getCanonicalParmVarDecl(const Decl * D)3547 static const Decl *getCanonicalParmVarDecl(const Decl *D) {
3548 // When storing ParmVarDecls in the local instantiation scope, we always
3549 // want to use the ParmVarDecl from the canonical function declaration,
3550 // since the map is then valid for any redeclaration or definition of that
3551 // function.
3552 if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(D)) {
3553 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(PV->getDeclContext())) {
3554 unsigned i = PV->getFunctionScopeIndex();
3555 // This parameter might be from a freestanding function type within the
3556 // function and isn't necessarily referring to one of FD's parameters.
3557 if (i < FD->getNumParams() && FD->getParamDecl(i) == PV)
3558 return FD->getCanonicalDecl()->getParamDecl(i);
3559 }
3560 }
3561 return D;
3562 }
3563
3564
3565 llvm::PointerUnion<Decl *, LocalInstantiationScope::DeclArgumentPack *> *
findInstantiationOf(const Decl * D)3566 LocalInstantiationScope::findInstantiationOf(const Decl *D) {
3567 D = getCanonicalParmVarDecl(D);
3568 for (LocalInstantiationScope *Current = this; Current;
3569 Current = Current->Outer) {
3570
3571 // Check if we found something within this scope.
3572 const Decl *CheckD = D;
3573 do {
3574 LocalDeclsMap::iterator Found = Current->LocalDecls.find(CheckD);
3575 if (Found != Current->LocalDecls.end())
3576 return &Found->second;
3577
3578 // If this is a tag declaration, it's possible that we need to look for
3579 // a previous declaration.
3580 if (const TagDecl *Tag = dyn_cast<TagDecl>(CheckD))
3581 CheckD = Tag->getPreviousDecl();
3582 else
3583 CheckD = nullptr;
3584 } while (CheckD);
3585
3586 // If we aren't combined with our outer scope, we're done.
3587 if (!Current->CombineWithOuterScope)
3588 break;
3589 }
3590
3591 // If we're performing a partial substitution during template argument
3592 // deduction, we may not have values for template parameters yet.
3593 if (isa<NonTypeTemplateParmDecl>(D) || isa<TemplateTypeParmDecl>(D) ||
3594 isa<TemplateTemplateParmDecl>(D))
3595 return nullptr;
3596
3597 // Local types referenced prior to definition may require instantiation.
3598 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D))
3599 if (RD->isLocalClass())
3600 return nullptr;
3601
3602 // Enumeration types referenced prior to definition may appear as a result of
3603 // error recovery.
3604 if (isa<EnumDecl>(D))
3605 return nullptr;
3606
3607 // Materialized typedefs/type alias for implicit deduction guides may require
3608 // instantiation.
3609 if (isa<TypedefNameDecl>(D) &&
3610 isa<CXXDeductionGuideDecl>(D->getDeclContext()))
3611 return nullptr;
3612
3613 // If we didn't find the decl, then we either have a sema bug, or we have a
3614 // forward reference to a label declaration. Return null to indicate that
3615 // we have an uninstantiated label.
3616 assert(isa<LabelDecl>(D) && "declaration not instantiated in this scope");
3617 return nullptr;
3618 }
3619
InstantiatedLocal(const Decl * D,Decl * Inst)3620 void LocalInstantiationScope::InstantiatedLocal(const Decl *D, Decl *Inst) {
3621 D = getCanonicalParmVarDecl(D);
3622 llvm::PointerUnion<Decl *, DeclArgumentPack *> &Stored = LocalDecls[D];
3623 if (Stored.isNull()) {
3624 #ifndef NDEBUG
3625 // It should not be present in any surrounding scope either.
3626 LocalInstantiationScope *Current = this;
3627 while (Current->CombineWithOuterScope && Current->Outer) {
3628 Current = Current->Outer;
3629 assert(Current->LocalDecls.find(D) == Current->LocalDecls.end() &&
3630 "Instantiated local in inner and outer scopes");
3631 }
3632 #endif
3633 Stored = Inst;
3634 } else if (DeclArgumentPack *Pack = Stored.dyn_cast<DeclArgumentPack *>()) {
3635 Pack->push_back(cast<VarDecl>(Inst));
3636 } else {
3637 assert(Stored.get<Decl *>() == Inst && "Already instantiated this local");
3638 }
3639 }
3640
InstantiatedLocalPackArg(const Decl * D,VarDecl * Inst)3641 void LocalInstantiationScope::InstantiatedLocalPackArg(const Decl *D,
3642 VarDecl *Inst) {
3643 D = getCanonicalParmVarDecl(D);
3644 DeclArgumentPack *Pack = LocalDecls[D].get<DeclArgumentPack *>();
3645 Pack->push_back(Inst);
3646 }
3647
MakeInstantiatedLocalArgPack(const Decl * D)3648 void LocalInstantiationScope::MakeInstantiatedLocalArgPack(const Decl *D) {
3649 #ifndef NDEBUG
3650 // This should be the first time we've been told about this decl.
3651 for (LocalInstantiationScope *Current = this;
3652 Current && Current->CombineWithOuterScope; Current = Current->Outer)
3653 assert(Current->LocalDecls.find(D) == Current->LocalDecls.end() &&
3654 "Creating local pack after instantiation of local");
3655 #endif
3656
3657 D = getCanonicalParmVarDecl(D);
3658 llvm::PointerUnion<Decl *, DeclArgumentPack *> &Stored = LocalDecls[D];
3659 DeclArgumentPack *Pack = new DeclArgumentPack;
3660 Stored = Pack;
3661 ArgumentPacks.push_back(Pack);
3662 }
3663
isLocalPackExpansion(const Decl * D)3664 bool LocalInstantiationScope::isLocalPackExpansion(const Decl *D) {
3665 for (DeclArgumentPack *Pack : ArgumentPacks)
3666 if (std::find(Pack->begin(), Pack->end(), D) != Pack->end())
3667 return true;
3668 return false;
3669 }
3670
SetPartiallySubstitutedPack(NamedDecl * Pack,const TemplateArgument * ExplicitArgs,unsigned NumExplicitArgs)3671 void LocalInstantiationScope::SetPartiallySubstitutedPack(NamedDecl *Pack,
3672 const TemplateArgument *ExplicitArgs,
3673 unsigned NumExplicitArgs) {
3674 assert((!PartiallySubstitutedPack || PartiallySubstitutedPack == Pack) &&
3675 "Already have a partially-substituted pack");
3676 assert((!PartiallySubstitutedPack
3677 || NumArgsInPartiallySubstitutedPack == NumExplicitArgs) &&
3678 "Wrong number of arguments in partially-substituted pack");
3679 PartiallySubstitutedPack = Pack;
3680 ArgsInPartiallySubstitutedPack = ExplicitArgs;
3681 NumArgsInPartiallySubstitutedPack = NumExplicitArgs;
3682 }
3683
getPartiallySubstitutedPack(const TemplateArgument ** ExplicitArgs,unsigned * NumExplicitArgs) const3684 NamedDecl *LocalInstantiationScope::getPartiallySubstitutedPack(
3685 const TemplateArgument **ExplicitArgs,
3686 unsigned *NumExplicitArgs) const {
3687 if (ExplicitArgs)
3688 *ExplicitArgs = nullptr;
3689 if (NumExplicitArgs)
3690 *NumExplicitArgs = 0;
3691
3692 for (const LocalInstantiationScope *Current = this; Current;
3693 Current = Current->Outer) {
3694 if (Current->PartiallySubstitutedPack) {
3695 if (ExplicitArgs)
3696 *ExplicitArgs = Current->ArgsInPartiallySubstitutedPack;
3697 if (NumExplicitArgs)
3698 *NumExplicitArgs = Current->NumArgsInPartiallySubstitutedPack;
3699
3700 return Current->PartiallySubstitutedPack;
3701 }
3702
3703 if (!Current->CombineWithOuterScope)
3704 break;
3705 }
3706
3707 return nullptr;
3708 }
3709